优化部分代码

src/N_m3u8DL-RE.Common/Entity/EncryptInfo.cs

@@ -1,9 +1,4 @@
 using N_m3u8DL_RE.Common.Enum;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace N_m3u8DL_RE.Common.Entity;
 
@@ -34,9 +29,6 @@ public class EncryptInfo
         {
             return m;
         }
-        else
+        return EncryptMethod.UNKNOWN;
-        {
-            return EncryptMethod.UNKNOWN;
-        }
     }
 }

src/N_m3u8DL-RE.Common/Entity/MediaPart.cs

@@ -3,5 +3,5 @@
 // 主要处理 EXT-X-DISCONTINUITY
 public class MediaPart
 {
-    public List<MediaSegment> MediaSegments { get; set; } = new List<MediaSegment>();
+    public List<MediaSegment> MediaSegments { get; set; } = [];
 }

src/N_m3u8DL-RE.Common/Entity/MediaSegment.cs

@@ -17,7 +17,7 @@ public class MediaSegment
     
     public bool IsEncrypted => EncryptInfo.Method != EncryptMethod.NONE;
 
-    public string Url { get; set; }
+    public string Url { get; set; } = string.Empty;
 
     public string? NameFromVar { get; set; } // MPD分段文件名
 

src/N_m3u8DL-RE.Common/Entity/Playlist.cs

@@ -3,17 +3,18 @@
 public class Playlist
 {
     // 对应Url信息
-    public string Url { get; set; }
+    public string Url { get; set; } = string.Empty;
     // 是否直播
     public bool IsLive { get; set; } = false;
     // 直播刷新间隔毫秒（默认15秒）
     public double RefreshIntervalMs { get; set; } = 15000;
     // 所有分片时长总和
-    public double TotalDuration { get => MediaParts.Sum(x => x.MediaSegments.Sum(m => m.Duration)); }
+    public double TotalDuration => MediaParts.Sum(x => x.MediaSegments.Sum(m => m.Duration));
+
     // 所有分片中最长时长
     public double? TargetDuration { get; set; }
     // INIT信息
     public MediaSegment? MediaInit { get; set; }
     // 分片信息
-    public List<MediaPart> MediaParts { get; set; } = new List<MediaPart>();
+    public List<MediaPart> MediaParts { get; set; } = [];
 }

src/N_m3u8DL-RE.Common/Entity/StreamSpec.cs

@@ -46,12 +46,12 @@ public class StreamSpec
     /// <summary>
     /// URL
     /// </summary>
-    public string Url { get; set; }
+    public string Url { get; set; } = string.Empty;
 
     /// <summary>
     /// 原始URL
     /// </summary>
-    public string OriginalUrl { get; set; }
+    public string OriginalUrl { get; set; } = string.Empty;
 
     public Playlist? Playlist { get; set; }
 

src/N_m3u8DL-RE.Common/Entity/WebVttSub.cs

@@ -11,10 +11,10 @@ public partial class WebVttSub
     private static partial Regex TSValueRegex();
     [GeneratedRegex("\\s")]
     private static partial Regex SplitRegex();
-    [GeneratedRegex("<c\\..*?>([\\s\\S]*?)<\\/c>")]
+    [GeneratedRegex(@"<c\..*?>([\s\S]*?)<\/c>")]
     private static partial Regex VttClassRegex();
 
-    public List<SubCue> Cues { get; set; } = new List<SubCue>();
+    public List<SubCue> Cues { get; set; } = [];
     public long MpegtsTimestamp { get; set; } = 0L;
 
     /// <summary>
@@ -71,47 +71,45 @@ public partial class WebVttSub
                 continue;
             }
 
-            if (needPayload)
+            if (!needPayload) continue;
+            
+            if (string.IsNullOrEmpty(line.Trim()))
             {
-                if (string.IsNullOrEmpty(line.Trim()))
+                var payload = string.Join(Environment.NewLine, payloads);
-                {
+                if (string.IsNullOrEmpty(payload.Trim())) continue; // 没获取到payload 跳过添加
-                    var payload = string.Join(Environment.NewLine, payloads);
-                    if (string.IsNullOrEmpty(payload.Trim())) continue; // 没获取到payload 跳过添加
 
-                    var arr = SplitRegex().Split(timeLine.Replace("-->", "")).Where(s => !string.IsNullOrEmpty(s)).ToList();
+                var arr = SplitRegex().Split(timeLine.Replace("-->", "")).Where(s => !string.IsNullOrEmpty(s)).ToList();
-                    var startTime = ConvertToTS(arr[0]);
+                var startTime = ConvertToTS(arr[0]);
-                    var endTime = ConvertToTS(arr[1]);
+                var endTime = ConvertToTS(arr[1]);
-                    var style = arr.Count > 2 ? string.Join(" ", arr.Skip(2)) : "";
+                var style = arr.Count > 2 ? string.Join(" ", arr.Skip(2)) : "";
-                    webSub.Cues.Add(new SubCue()
+                webSub.Cues.Add(new SubCue()
-                    {
-                        StartTime = startTime,
-                        EndTime = endTime,
-                        Payload = RemoveClassTag(string.Join("", payload.Where(c => c != 8203))), // Remove Zero Width Space!
-                        Settings = style
-                    });
-                    payloads.Clear();
-                    needPayload = false;
-                }
-                else
                 {
-                    payloads.Add(line.Trim());
+                    StartTime = startTime,
-                }
+                    EndTime = endTime,
+                    Payload = RemoveClassTag(string.Join("", payload.Where(c => c != 8203))), // Remove Zero Width Space!
+                    Settings = style
+                });
+                payloads.Clear();
+                needPayload = false;
+            }
+            else
+            {
+                payloads.Add(line.Trim());
             }
         }
 
-        if (BaseTimestamp != 0)
+        if (BaseTimestamp == 0) return webSub;
+        
+        foreach (var item in webSub.Cues)
         {
-            foreach (var item in webSub.Cues)
+            if (item.StartTime.TotalMilliseconds - BaseTimestamp >= 0)
             {
-                if (item.StartTime.TotalMilliseconds - BaseTimestamp >= 0)
+                item.StartTime = TimeSpan.FromMilliseconds(item.StartTime.TotalMilliseconds - BaseTimestamp);
-                {
+                item.EndTime = TimeSpan.FromMilliseconds(item.EndTime.TotalMilliseconds - BaseTimestamp);
-                    item.StartTime = TimeSpan.FromMilliseconds(item.StartTime.TotalMilliseconds - BaseTimestamp);
+            }
-                    item.EndTime = TimeSpan.FromMilliseconds(item.EndTime.TotalMilliseconds - BaseTimestamp);
+            else
-                }
+            {
-                else
+                break;
-                {
-                    break;
-                }
             }
         }
 
@@ -127,7 +125,7 @@ public partial class WebVttSub
                 return string.Concat(VttClassRegex().Matches(line).Select(x => x.Groups[1].Value + " "));
             })).TrimEnd();
         }
-        else return text;
+        return text;
     }
 
     /// <summary>
@@ -140,18 +138,17 @@ public partial class WebVttSub
         FixTimestamp(webSub, this.MpegtsTimestamp);
         foreach (var item in webSub.Cues)
         {
-            if (!this.Cues.Contains(item))
+            if (this.Cues.Contains(item)) continue;
+            
+            // 如果相差只有1ms，且payload相同，则拼接
+            var last = this.Cues.LastOrDefault();
+            if (last != null && this.Cues.Count > 0 && (item.StartTime - last.EndTime).TotalMilliseconds <= 1 && item.Payload == last.Payload) 
             {
-                // 如果相差只有1ms，且payload相同，则拼接
+                last.EndTime = item.EndTime;
-                var last = this.Cues.LastOrDefault();
+            }
-                if (last != null && this.Cues.Count > 0 && (item.StartTime - last.EndTime).TotalMilliseconds <= 1 && item.Payload == last.Payload) 
+            else
-                {
+            {
-                    last.EndTime = item.EndTime;
+                this.Cues.Add(item);
-                }
-                else
-                {
-                    this.Cues.Add(item);
-                }
             }
         }
         return this;
@@ -173,10 +170,10 @@ public partial class WebVttSub
             // 当前预添加的字幕的起始时间小于实际上已经走过的时间(如offset已经是100秒，而字幕起始却是2秒)，才修复
             if (sub.Cues.Count > 0 && sub.Cues.First().StartTime < offset)
             {
-                for (int i = 0; i < sub.Cues.Count; i++)
+                foreach (var subCue in sub.Cues)
                 {
-                    sub.Cues[i].StartTime += offset;
+                    subCue.StartTime += offset;
-                    sub.Cues[i].EndTime += offset;
+                    subCue.EndTime += offset;
                 }
             }
         }
@@ -205,7 +202,7 @@ public partial class WebVttSub
             str = parts.First();
         }
         var t = str.Split(':').Reverse().ToList();
-        for (int i = 0; i < t.Count(); i++)
+        for (int i = 0; i < t.Count; i++)
         {
             time += (long)Math.Pow(60, i) * Convert.ToInt32(t[i]) * 1000;
         }
@@ -214,7 +211,7 @@ public partial class WebVttSub
 
     public override string ToString()
     {
-        StringBuilder sb = new StringBuilder();
+        var sb = new StringBuilder();
         foreach (var c in GetCues())  // 输出时去除空串
         {
             sb.AppendLine(c.StartTime.ToString(@"hh\:mm\:ss\.fff") + " --> " + c.EndTime.ToString(@"hh\:mm\:ss\.fff") + " " + c.Settings);

src/N_m3u8DL-RE.Common/JsonConverter/BytesBase64Converter.cs

@@ -1,10 +1,5 @@
-using System;
+using System.Text.Json;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Text.Json;
 using System.Text.Json.Serialization;
-using System.Threading.Tasks;
 
 namespace N_m3u8DL_RE.Common.JsonConverter;
 

src/N_m3u8DL-RE.Common/Log/CustomAnsiConsole.cs

@@ -4,7 +4,7 @@ using Spectre.Console;
 
 namespace N_m3u8DL_RE.Common.Log;
 
-public class NonAnsiWriter : TextWriter
+public partial class NonAnsiWriter : TextWriter
 {
     public override Encoding Encoding => Console.OutputEncoding;
 
@@ -28,15 +28,22 @@ public class NonAnsiWriter : TextWriter
     private void RemoveAnsiEscapeSequences(string? input)
     {
         // Use regular expression to remove ANSI escape sequences
-        string output = Regex.Replace(input ?? "", @"\x1B\[(\d+;?)+m", "");
+        var output = MyRegex().Replace(input ?? "", "");
-        output = Regex.Replace(output, @"\[\??\d+[AKlh]", "");
+        output = MyRegex1().Replace(output, "");
-        output = Regex.Replace(output,"[\r\n] +","");
+        output = MyRegex2().Replace(output, "");
         if (string.IsNullOrWhiteSpace(output))
         {
             return;
         }
         Console.Write(output);
     }
+
+    [GeneratedRegex(@"\x1B\[(\d+;?)+m")]
+    private static partial Regex MyRegex();
+    [GeneratedRegex(@"\[\??\d+[AKlh]")]
+    private static partial Regex MyRegex1();
+    [GeneratedRegex("[\r\n] +")]
+    private static partial Regex MyRegex2();
 }
 
 /// <summary>

src/N_m3u8DL-RE.Common/Log/LogLevel.cs

@@ -1,10 +1,4 @@
-using System;
+namespace N_m3u8DL_RE.Common.Log;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace N_m3u8DL_RE.Common.Log;
 
 public enum LogLevel
 {

src/N_m3u8DL-RE.Common/Log/Logger.cs

@@ -4,7 +4,7 @@ using System.Text.RegularExpressions;
 
 namespace N_m3u8DL_RE.Common.Log;
 
-public partial class Logger
+public static partial class Logger
 {
     [GeneratedRegex("{}")]
     private static partial Regex VarsRepRegex();
@@ -80,24 +80,23 @@ public partial class Logger
                 Console.WriteLine(subWrite);
             }
 
-            if (IsWriteFile && File.Exists(LogFilePath))
+            if (!IsWriteFile || !File.Exists(LogFilePath)) return;
+            
+            var plain = write.RemoveMarkup() + subWrite.RemoveMarkup();
+            try
             {
-                var plain = write.RemoveMarkup() + subWrite.RemoveMarkup();
+                // 进入写入
-                try
+                LogWriteLock.EnterWriteLock();
+                using (StreamWriter sw = File.AppendText(LogFilePath))
                 {
-                    // 进入写入
+                    sw.WriteLine(plain);
-                    LogWriteLock.EnterWriteLock();
-                    using (StreamWriter sw = File.AppendText(LogFilePath))
-                    {
-                        sw.WriteLine(plain);
-                    }
-                }
-                finally
-                {
-                    // 释放占用
-                    LogWriteLock.ExitWriteLock();
                 }
             }
+            finally
+            {
+                // 释放占用
+                LogWriteLock.ExitWriteLock();
+            }
         }
         catch (Exception)
         {
@@ -117,82 +116,74 @@ public partial class Logger
 
     public static void Info(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.INFO)
+        if (LogLevel < LogLevel.INFO) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline #548c26]INFO[/] : ";
+        var write = GetCurrTime() + " " + "[underline #548c26]INFO[/] : ";
-            HandleLog(write, data);
+        HandleLog(write, data);
-        }
     }
 
     public static void InfoMarkUp(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.INFO)
+        if (LogLevel < LogLevel.INFO) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline #548c26]INFO[/] : " + data;
+        var write = GetCurrTime() + " " + "[underline #548c26]INFO[/] : " + data;
-            HandleLog(write);
+        HandleLog(write);
-        }
     }
 
     public static void Debug(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.DEBUG)
+        if (LogLevel < LogLevel.DEBUG) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline grey]DEBUG[/]: ";
+        var write = GetCurrTime() + " " + "[underline grey]DEBUG[/]: ";
-            HandleLog(write, data);
+        HandleLog(write, data);
-        }
     }
 
     public static void DebugMarkUp(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.DEBUG)
+        if (LogLevel < LogLevel.DEBUG) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline grey]DEBUG[/]: " + data;
+        var write = GetCurrTime() + " " + "[underline grey]DEBUG[/]: " + data;
-            HandleLog(write);
+        HandleLog(write);
-        }
     }
 
     public static void Warn(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.WARN)
+        if (LogLevel < LogLevel.WARN) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline #a89022]WARN[/] : ";
+        var write = GetCurrTime() + " " + "[underline #a89022]WARN[/] : ";
-            HandleLog(write, data);
+        HandleLog(write, data);
-        }
     }
 
     public static void WarnMarkUp(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.WARN)
+        if (LogLevel < LogLevel.WARN) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline #a89022]WARN[/] : " + data;
+        var write = GetCurrTime() + " " + "[underline #a89022]WARN[/] : " + data;
-            HandleLog(write);
+        HandleLog(write);
-        }
     }
 
     public static void Error(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.ERROR)
+        if (LogLevel < LogLevel.ERROR) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline red1]ERROR[/]: ";
+        var write = GetCurrTime() + " " + "[underline red1]ERROR[/]: ";
-            HandleLog(write, data);
+        HandleLog(write, data);
-        }
     }
 
     public static void ErrorMarkUp(string data, params object[] ps)
     {
-        if (LogLevel >= LogLevel.ERROR)
+        if (LogLevel < LogLevel.ERROR) return;
-        {
+        
-            data = ReplaceVars(data, ps);
+        data = ReplaceVars(data, ps);
-            var write = GetCurrTime() + " " + "[underline red1]ERROR[/]: " + data;
+        var write = GetCurrTime() + " " + "[underline red1]ERROR[/]: " + data;
-            HandleLog(write);
+        HandleLog(write);
-        }
     }
 
     public static void ErrorMarkUp(Exception exception)
@@ -213,24 +204,23 @@ public partial class Logger
     /// <param name="ps"></param>
     public static void Extra(string data, params object[] ps)
     {
-        if (IsWriteFile && File.Exists(LogFilePath))
+        if (!IsWriteFile || !File.Exists(LogFilePath)) return;
+        
+        data = ReplaceVars(data, ps);
+        var plain = GetCurrTime() + " " + "EXTRA: " + data.RemoveMarkup();
+        try
         {
-            data = ReplaceVars(data, ps);
+            // 进入写入
-            var plain = GetCurrTime() + " " + "EXTRA: " + data.RemoveMarkup();
+            LogWriteLock.EnterWriteLock();
-            try
+            using (StreamWriter sw = File.AppendText(LogFilePath))
             {
-                // 进入写入
+                sw.WriteLine(plain, Encoding.UTF8);
-                LogWriteLock.EnterWriteLock();
-                using (StreamWriter sw = File.AppendText(LogFilePath))
-                {
-                    sw.WriteLine(plain, Encoding.UTF8);
-                }
-            }
-            finally
-            {
-                // 释放占用
-                LogWriteLock.ExitWriteLock();
             }
         }
+        finally
+        {
+            // 释放占用
+            LogWriteLock.ExitWriteLock();
+        }
     }
 }

src/N_m3u8DL-RE.Common/Resource/ResString.cs

@@ -2,7 +2,7 @@
 
 public static class ResString
 {
-    public static string CurrentLoc = "en-US";
+    public static string CurrentLoc { get; set; } = "en-US";
 
     public static readonly string ReLiveTs = "<RE_LIVE_TS>";
     public static string singleFileRealtimeDecryptWarn => GetText("singleFileRealtimeDecryptWarn");
@@ -140,13 +140,11 @@ public static class ResString
 
     private static string GetText(string key)
     {
-        if (!StaticText.LANG_DIC.ContainsKey(key))
+        if (!StaticText.LANG_DIC.TryGetValue(key, out var textObj))
             return "<...LANG TEXT MISSING...>";
 
-        if (CurrentLoc == "zh-CN" || CurrentLoc == "zh-SG" || CurrentLoc == "zh-Hans")
+        if (CurrentLoc is "zh-CN" or "zh-SG" or "zh-Hans")
-            return StaticText.LANG_DIC[key].ZH_CN;
+            return textObj.ZH_CN;
-        if (CurrentLoc.StartsWith("zh-"))
+        return CurrentLoc.StartsWith("zh-") ? textObj.ZH_TW : textObj.EN_US;
-            return StaticText.LANG_DIC[key].ZH_TW;
-        return StaticText.LANG_DIC[key].EN_US;
     }
 }

src/N_m3u8DL-RE.Common/Resource/StaticText.cs

@@ -1,14 +1,8 @@
-using System;
+namespace N_m3u8DL_RE.Common.Resource;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
-namespace N_m3u8DL_RE.Common.Resource;
+internal static class StaticText
-
-internal class StaticText
 {
-    public static Dictionary<string, TextContainer> LANG_DIC = new()
+    public static readonly Dictionary<string, TextContainer> LANG_DIC = new()
     {
         ["singleFileSplitWarn"] = new TextContainer
         (
@@ -228,9 +222,9 @@ internal class StaticText
         ),
         ["cmd_decryptionBinaryPath"] = new TextContainer
         (
-            zhCN: "MP4解密所用工具的全路径, 例如 C:\\Tools\\mp4decrypt.exe",
+            zhCN: @"MP4解密所用工具的全路径, 例如 C:\Tools\mp4decrypt.exe",
-            zhTW: "MP4解密所用工具的全路徑, 例如 C:\\Tools\\mp4decrypt.exe",
+            zhTW: @"MP4解密所用工具的全路徑, 例如 C:\Tools\mp4decrypt.exe",
-            enUS: "Full path to the tool used for MP4 decryption, like C:\\Tools\\mp4decrypt.exe"
+            enUS: @"Full path to the tool used for MP4 decryption, like C:\Tools\mp4decrypt.exe"
         ),
         ["cmd_delAfterDone"] = new TextContainer
         (
@@ -240,15 +234,15 @@ internal class StaticText
         ),
         ["cmd_ffmpegBinaryPath"] = new TextContainer
         (
-            zhCN: "ffmpeg可执行程序全路径, 例如 C:\\Tools\\ffmpeg.exe",
+            zhCN: @"ffmpeg可执行程序全路径, 例如 C:\Tools\ffmpeg.exe",
-            zhTW: "ffmpeg可執行程序全路徑, 例如 C:\\Tools\\ffmpeg.exe",
+            zhTW: @"ffmpeg可執行程序全路徑, 例如 C:\Tools\ffmpeg.exe",
-            enUS: "Full path to the ffmpeg binary, like C:\\Tools\\ffmpeg.exe"
+            enUS: @"Full path to the ffmpeg binary, like C:\Tools\ffmpeg.exe"
         ),
         ["cmd_mkvmergeBinaryPath"] = new TextContainer
         (
-            zhCN: "mkvmerge可执行程序全路径, 例如 C:\\Tools\\mkvmerge.exe",
+            zhCN: @"mkvmerge可执行程序全路径, 例如 C:\Tools\mkvmerge.exe",
-            zhTW: "mkvmerge可執行程序全路徑, 例如 C:\\Tools\\mkvmerge.exe",
+            zhTW: @"mkvmerge可執行程序全路徑, 例如 C:\Tools\mkvmerge.exe",
-            enUS: "Full path to the mkvmerge binary, like C:\\Tools\\mkvmerge.exe"
+            enUS: @"Full path to the mkvmerge binary, like C:\Tools\mkvmerge.exe"
         ),
         ["cmd_liveFixVttByAudio"] = new TextContainer
         (

src/N_m3u8DL-RE.Common/Util/GlobalUtil.cs

@@ -67,8 +67,7 @@ public static class GlobalUtil
     {
         var fileExt = OperatingSystem.IsWindows() ? ".exe" : "";
         var searchPath = new[] { Environment.CurrentDirectory, Path.GetDirectoryName(Environment.ProcessPath) };
-        var envPath = Environment.GetEnvironmentVariable("PATH")?.Split(Path.PathSeparator) ??
+        var envPath = Environment.GetEnvironmentVariable("PATH")?.Split(Path.PathSeparator) ?? [];
-                      Array.Empty<string>();
         return searchPath.Concat(envPath).Select(p => Path.Combine(p!, name + fileExt)).FirstOrDefault(File.Exists);
     }
 }

src/N_m3u8DL-RE.Common/Util/HTTPUtil.cs

@@ -99,7 +99,7 @@ public static class HTTPUtil
     private static bool CheckMPEG2TS(HttpResponseMessage? webResponse)
     {
         var mediaType = webResponse?.Content.Headers.ContentType?.MediaType?.ToLower();
-        return mediaType == "video/ts" || mediaType == "video/mp2t" || mediaType == "video/mpeg";
+        return mediaType is "video/ts" or "video/mp2t" or "video/mpeg";
     }
 
     /// <summary>

src/N_m3u8DL-RE.Parser/Config/ParserConfig.cs

@@ -7,11 +7,11 @@ namespace N_m3u8DL_RE.Parser.Config;
 
 public class ParserConfig
 {
-    public string Url { get; set; }
+    public string Url { get; set; } = string.Empty;
 
-    public string OriginalUrl { get; set; }
+    public string OriginalUrl { get; set; } = string.Empty;
 
-    public string BaseUrl { get; set; }
+    public string BaseUrl { get; set; } = string.Empty;
     
     public Dictionary<string, string> CustomParserArgs { get; } = new();
 

src/N_m3u8DL-RE.Parser/Constants/DASHTags.cs

@@ -1,15 +1,9 @@
-using System;
+namespace N_m3u8DL_RE.Parser.Constants;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
-namespace N_m3u8DL_RE.Parser.Constants;
+internal static class DASHTags
-
-internal class DASHTags
 {
-    public static string TemplateRepresentationID = "$RepresentationID$";
+    public const string TemplateRepresentationID = "$RepresentationID$";
-    public static string TemplateBandwidth = "$Bandwidth$";
+    public const string TemplateBandwidth = "$Bandwidth$";
-    public static string TemplateNumber = "$Number$";
+    public const string TemplateNumber = "$Number$";
-    public static string TemplateTime = "$Time$";
+    public const string TemplateTime = "$Time$";
 }

src/N_m3u8DL-RE.Parser/Constants/HLSTags.cs

@@ -1,37 +1,31 @@
-using System;
+namespace N_m3u8DL_RE.Parser.Constants;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
-namespace N_m3u8DL_RE.Parser.Constants;
+internal static class HLSTags
-
-internal class HLSTags
 {
-    public static string ext_m3u = "#EXTM3U";
+    public const string ext_m3u = "#EXTM3U";
-    public static string ext_x_targetduration = "#EXT-X-TARGETDURATION";
+    public const string ext_x_targetduration = "#EXT-X-TARGETDURATION";
-    public static string ext_x_media_sequence = "#EXT-X-MEDIA-SEQUENCE";
+    public const string ext_x_media_sequence = "#EXT-X-MEDIA-SEQUENCE";
-    public static string ext_x_discontinuity_sequence = "#EXT-X-DISCONTINUITY-SEQUENCE";
+    public const string ext_x_discontinuity_sequence = "#EXT-X-DISCONTINUITY-SEQUENCE";
-    public static string ext_x_program_date_time = "#EXT-X-PROGRAM-DATE-TIME";
+    public const string ext_x_program_date_time = "#EXT-X-PROGRAM-DATE-TIME";
-    public static string ext_x_media = "#EXT-X-MEDIA";
+    public const string ext_x_media = "#EXT-X-MEDIA";
-    public static string ext_x_playlist_type = "#EXT-X-PLAYLIST-TYPE";
+    public const string ext_x_playlist_type = "#EXT-X-PLAYLIST-TYPE";
-    public static string ext_x_key = "#EXT-X-KEY";
+    public const string ext_x_key = "#EXT-X-KEY";
-    public static string ext_x_stream_inf = "#EXT-X-STREAM-INF";
+    public const string ext_x_stream_inf = "#EXT-X-STREAM-INF";
-    public static string ext_x_version = "#EXT-X-VERSION";
+    public const string ext_x_version = "#EXT-X-VERSION";
-    public static string ext_x_allow_cache = "#EXT-X-ALLOW-CACHE";
+    public const string ext_x_allow_cache = "#EXT-X-ALLOW-CACHE";
-    public static string ext_x_endlist = "#EXT-X-ENDLIST";
+    public const string ext_x_endlist = "#EXT-X-ENDLIST";
-    public static string extinf = "#EXTINF";
+    public const string extinf = "#EXTINF";
-    public static string ext_i_frames_only = "#EXT-X-I-FRAMES-ONLY";
+    public const string ext_i_frames_only = "#EXT-X-I-FRAMES-ONLY";
-    public static string ext_x_byterange = "#EXT-X-BYTERANGE";
+    public const string ext_x_byterange = "#EXT-X-BYTERANGE";
-    public static string ext_x_i_frame_stream_inf = "#EXT-X-I-FRAME-STREAM-INF";
+    public const string ext_x_i_frame_stream_inf = "#EXT-X-I-FRAME-STREAM-INF";
-    public static string ext_x_discontinuity = "#EXT-X-DISCONTINUITY";
+    public const string ext_x_discontinuity = "#EXT-X-DISCONTINUITY";
-    public static string ext_x_cue_out_start = "#EXT-X-CUE-OUT";
+    public const string ext_x_cue_out_start = "#EXT-X-CUE-OUT";
-    public static string ext_x_cue_out = "#EXT-X-CUE-OUT-CONT";
+    public const string ext_x_cue_out = "#EXT-X-CUE-OUT-CONT";
-    public static string ext_is_independent_segments = "#EXT-X-INDEPENDENT-SEGMENTS";
+    public const string ext_is_independent_segments = "#EXT-X-INDEPENDENT-SEGMENTS";
-    public static string ext_x_scte35 = "#EXT-OATCLS-SCTE35";
+    public const string ext_x_scte35 = "#EXT-OATCLS-SCTE35";
-    public static string ext_x_cue_start = "#EXT-X-CUE-OUT";
+    public const string ext_x_cue_start = "#EXT-X-CUE-OUT";
-    public static string ext_x_cue_end = "#EXT-X-CUE-IN";
+    public const string ext_x_cue_end = "#EXT-X-CUE-IN";
-    public static string ext_x_cue_span = "#EXT-X-CUE-SPAN";
+    public const string ext_x_cue_span = "#EXT-X-CUE-SPAN";
-    public static string ext_x_map = "#EXT-X-MAP";
+    public const string ext_x_map = "#EXT-X-MAP";
-    public static string ext_x_start = "#EXT-X-START";
+    public const string ext_x_start = "#EXT-X-START";
 }

src/N_m3u8DL-RE.Parser/Constants/MSSTags.cs

@@ -1,15 +1,9 @@
-using System;
+namespace N_m3u8DL_RE.Parser.Constants;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
-namespace N_m3u8DL_RE.Parser.Constants;
+internal static class MSSTags
-
-internal class MSSTags
 {
-    public static string Bitrate = "{Bitrate}";
+    public const string Bitrate = "{Bitrate}";
-    public static string Bitrate_BK = "{bitrate}";
+    public const string Bitrate_BK = "{bitrate}";
-    public static string StartTime = "{start_time}";
+    public const string StartTime = "{start_time}";
-    public static string StartTime_BK = "{start time}";
+    public const string StartTime_BK = "{start time}";
 }

src/N_m3u8DL-RE.Parser/Extractor/DASHExtractor2.cs

@@ -4,19 +4,14 @@ using N_m3u8DL_RE.Common.Util;
 using N_m3u8DL_RE.Parser.Config;
 using N_m3u8DL_RE.Parser.Constants;
 using N_m3u8DL_RE.Parser.Util;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 using System.Xml;
 using System.Xml.Linq;
 
 namespace N_m3u8DL_RE.Parser.Extractor;
 
 // https://blog.csdn.net/leek5533/article/details/117750191
-internal class DASHExtractor2 : IExtractor
+internal partial class DASHExtractor2 : IExtractor
 {
     private static EncryptMethod DEFAULT_METHOD = EncryptMethod.CENC;
 
@@ -37,10 +32,7 @@ internal class DASHExtractor2 : IExtractor
     private void SetInitUrl()
     {
         this.MpdUrl = ParserConfig.Url ?? string.Empty;
-        if (!string.IsNullOrEmpty(ParserConfig.BaseUrl))
+        this.BaseUrl = !string.IsNullOrEmpty(ParserConfig.BaseUrl) ? ParserConfig.BaseUrl : this.MpdUrl;
-            this.BaseUrl = ParserConfig.BaseUrl;
-        else
-            this.BaseUrl = this.MpdUrl;
     }
 
     private string ExtendBaseUrl(XElement element, string oriBaseUrl)
@@ -57,13 +49,11 @@ internal class DASHExtractor2 : IExtractor
     private double? GetFrameRate(XElement element)
     {
         var frameRate = element.Attribute("frameRate")?.Value;
-        if (frameRate != null && frameRate.Contains('/'))
+        if (frameRate == null || !frameRate.Contains('/')) return null;
-        {
+        
-            var d = Convert.ToDouble(frameRate.Split('/')[0]) / Convert.ToDouble(frameRate.Split('/')[1]);
+        var d = Convert.ToDouble(frameRate.Split('/')[0]) / Convert.ToDouble(frameRate.Split('/')[1]);
-            frameRate = d.ToString("0.000");
+        frameRate = d.ToString("0.000");
-            return Convert.ToDouble(frameRate);
+        return Convert.ToDouble(frameRate);
-        }
-        return null;
     }
 
     public Task<List<StreamSpec>> ExtractStreamsAsync(string rawText)
@@ -180,7 +170,7 @@ internal class DASHExtractor2 : IExtractor
                         streamSpec.Extension = mTypeSplit.Length == 2 ? mTypeSplit[1] : null;
                     }
                     // 优化字幕场景识别
-                    if (streamSpec.Codecs == "stpp" || streamSpec.Codecs == "wvtt")
+                    if (streamSpec.Codecs is "stpp" or "wvtt")
                     {
                         streamSpec.MediaType = MediaType.SUBTITLES;
                     }
@@ -493,7 +483,7 @@ internal class DASHExtractor2 : IExtractor
                     else
                     {
                         // 修复mp4类型字幕
-                        if (streamSpec.MediaType == MediaType.SUBTITLES && streamSpec.Extension == "mp4")
+                        if (streamSpec is { MediaType: MediaType.SUBTITLES, Extension: "mp4" })
                         {
                             streamSpec.Extension = "m4s";
                         }
@@ -513,20 +503,17 @@ internal class DASHExtractor2 : IExtractor
         }
 
         // 为视频设置默认轨道
-        var aL = streamList.Where(s => s.MediaType == MediaType.AUDIO);
+        var aL = streamList.Where(s => s.MediaType == MediaType.AUDIO).ToList();
-        var sL = streamList.Where(s => s.MediaType == MediaType.SUBTITLES);
+        var sL = streamList.Where(s => s.MediaType == MediaType.SUBTITLES).ToList();
-        foreach (var item in streamList)
+        foreach (var item in streamList.Where(item => !string.IsNullOrEmpty(item.Resolution)))
         {
-            if (!string.IsNullOrEmpty(item.Resolution))
+            if (aL.Count != 0)
             {
-                if (aL.Any())
+                item.AudioId = aL.OrderByDescending(x => x.Bandwidth).First().GroupId;
-                {
+            }
-                    item.AudioId = aL.OrderByDescending(x => x.Bandwidth).First().GroupId;
+            if (sL.Count != 0)
-                }
+            {
-                if (sL.Any())
+                item.SubtitleId = sL.OrderByDescending(x => x.Bandwidth).First().GroupId;
-                {
-                    item.SubtitleId = sL.OrderByDescending(x => x.Bandwidth).First().GroupId;
-                }
             }
         }
 
@@ -541,8 +528,7 @@ internal class DASHExtractor2 : IExtractor
     private string? FilterLanguage(string? v)
     {
         if (v == null) return null;
-        if (Regex.IsMatch(v, "^[\\w_\\-\\d]+$")) return v;
+        return LangCodeRegex().IsMatch(v) ? v : "und";
-        return "und";
     }
 
     public async Task RefreshPlayListAsync(List<StreamSpec> streamSpecs)
@@ -581,22 +567,21 @@ internal class DASHExtractor2 : IExtractor
 
     private Task ProcessUrlAsync(List<StreamSpec> streamSpecs)
     {
-        for (int i = 0; i < streamSpecs.Count; i++)
+        foreach (var streamSpec in streamSpecs)
         {
-            var playlist = streamSpecs[i].Playlist;
+            var playlist = streamSpec.Playlist;
-            if (playlist != null)
+            if (playlist == null) continue;
+            
+            if (playlist.MediaInit != null)
             {
-                if (playlist.MediaInit != null)
+                playlist.MediaInit!.Url = PreProcessUrl(playlist.MediaInit!.Url);
+            }
+            for (var ii = 0; ii < playlist!.MediaParts.Count; ii++)
+            {
+                var part = playlist.MediaParts[ii];
+                foreach (var mediaSegment in part.MediaSegments)
                 {
-                    playlist.MediaInit!.Url = PreProcessUrl(playlist.MediaInit!.Url);
+                    mediaSegment.Url = PreProcessUrl(mediaSegment.Url);
-                }
-                for (int ii = 0; ii < playlist!.MediaParts.Count; ii++)
-                {
-                    var part = playlist.MediaParts[ii];
-                    for (int iii = 0; iii < part.MediaSegments.Count; iii++)
-                    {
-                        part.MediaSegments[iii].Url = PreProcessUrl(part.MediaSegments[iii].Url);
-                    }
                 }
             }
         }
@@ -633,4 +618,7 @@ internal class DASHExtractor2 : IExtractor
             }
         }
     }
+
+    [GeneratedRegex(@"^[\w_\-\d]+$")]
+    private static partial Regex LangCodeRegex();
 }

src/N_m3u8DL-RE.Parser/Extractor/HLSExtractor.cs

@@ -5,12 +5,6 @@ using N_m3u8DL_RE.Common.Log;
 using N_m3u8DL_RE.Common.Resource;
 using N_m3u8DL_RE.Parser.Util;
 using N_m3u8DL_RE.Parser.Constants;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 using N_m3u8DL_RE.Common.Util;
 
 namespace N_m3u8DL_RE.Parser.Extractor;
@@ -26,8 +20,6 @@ internal class HLSExtractor : IExtractor
 
     public ParserConfig ParserConfig { get; set; }
 
-    private HLSExtractor() { }
-
     public HLSExtractor(ParserConfig parserConfig)
     {
         this.ParserConfig = parserConfig;
@@ -37,14 +29,7 @@ internal class HLSExtractor : IExtractor
 
     private void SetBaseUrl()
     {
-        if (!string.IsNullOrEmpty(ParserConfig.BaseUrl))
+        this.BaseUrl = !string.IsNullOrEmpty(ParserConfig.BaseUrl) ? ParserConfig.BaseUrl : this.M3u8Url;
-        {
-            this.BaseUrl = ParserConfig.BaseUrl;
-        }
-        else
-        {
-            this.BaseUrl = this.M3u8Url;
-        }
     }
 
     /// <summary>
@@ -87,7 +72,7 @@ internal class HLSExtractor : IExtractor
     {
         MasterM3u8Flag = true;
 
-        List<StreamSpec> streams = new List<StreamSpec>();
+        List<StreamSpec> streams = [];
 
         using StringReader sr = new StringReader(M3u8Content);
         string? line;
@@ -201,7 +186,7 @@ internal class HLSExtractor : IExtractor
 
                 streams.Add(streamSpec);
             }
-            else if (line.StartsWith("#"))
+            else if (line.StartsWith('#'))
             {
                 continue;
             }
@@ -237,22 +222,22 @@ internal class HLSExtractor : IExtractor
         long startIndex;
 
         Playlist playlist = new();
-        List<MediaPart> mediaParts = new();
+        List<MediaPart> mediaParts = [];
 
         // 当前的加密信息
         EncryptInfo currentEncryptInfo = new();
         if (ParserConfig.CustomMethod != null)
             currentEncryptInfo.Method = ParserConfig.CustomMethod.Value;
-        if (ParserConfig.CustomeKey != null && ParserConfig.CustomeKey.Length > 0) 
+        if (ParserConfig.CustomeKey is { Length: > 0 }) 
             currentEncryptInfo.Key = ParserConfig.CustomeKey;
-        if (ParserConfig.CustomeIV != null && ParserConfig.CustomeIV.Length > 0)
+        if (ParserConfig.CustomeIV is { Length: > 0 })
             currentEncryptInfo.IV = ParserConfig.CustomeIV;
         // 上次读取到的加密行，#EXT-X-KEY:……
         string lastKeyLine = "";
 
         MediaPart mediaPart = new();
         MediaSegment segment = new();
-        List<MediaSegment> segments = new();
+        List<MediaSegment> segments = [];
 
 
         while ((line = sr.ReadLine()) != null)
@@ -304,20 +289,19 @@ internal class HLSExtractor : IExtractor
                 // 修复YK去除广告后的遗留问题
                 if (hasAd && mediaParts.Count > 0)
                 {
-                    segments = mediaParts[mediaParts.Count - 1].MediaSegments;
+                    segments = mediaParts[^1].MediaSegments;
                     mediaParts.RemoveAt(mediaParts.Count - 1);
                     hasAd = false;
                     continue;
                 }
                 // 常规情况的#EXT-X-DISCONTINUITY标记，新建part
-                if (!hasAd && segments.Count >= 1)
+                if (hasAd || segments.Count < 1) continue;
+                
+                mediaParts.Add(new MediaPart
                 {
-                    mediaParts.Add(new MediaPart()
+                    MediaSegments = segments,
-                    {
+                });
-                        MediaSegments = segments,
+                segments = new();
-                    });
-                    segments = new();
-                }
             }
             // 解析KEY
             else if (line.StartsWith(HLSTags.ext_x_key))
@@ -382,13 +366,11 @@ internal class HLSExtractor : IExtractor
                         playlist.MediaInit.ExpectLength = n;
                         playlist.MediaInit.StartRange = o ?? 0L;
                     }
-                    // 是否有加密，有的话写入KEY和IV
+                    if (currentEncryptInfo.Method == EncryptMethod.NONE) continue;
-                    if (currentEncryptInfo.Method != EncryptMethod.NONE)
+                    // 有加密的话写入KEY和IV
-                    {
+                    playlist.MediaInit.EncryptInfo.Method = currentEncryptInfo.Method;
-                        playlist.MediaInit.EncryptInfo.Method = currentEncryptInfo.Method;
+                    playlist.MediaInit.EncryptInfo.Key = currentEncryptInfo.Key;
-                        playlist.MediaInit.EncryptInfo.Key = currentEncryptInfo.Key;
+                    playlist.MediaInit.EncryptInfo.IV = currentEncryptInfo.IV ?? HexUtil.HexToBytes(Convert.ToString(segIndex, 16).PadLeft(32, '0'));
-                        playlist.MediaInit.EncryptInfo.IV = currentEncryptInfo.IV ?? HexUtil.HexToBytes(Convert.ToString(segIndex, 16).PadLeft(32, '0'));
-                    }
                 }
                 // 遇到了其他的map，说明已经不是一个视频了，全部丢弃即可
                 else
@@ -409,7 +391,7 @@ internal class HLSExtractor : IExtractor
                 }
             }
             // 评论行不解析
-            else if (line.StartsWith("#")) continue;
+            else if (line.StartsWith('#')) continue;
             // 空白行不解析
             else if (line.StartsWith("\r\n")) continue;
             // 解析分片的地址
@@ -488,15 +470,15 @@ internal class HLSExtractor : IExtractor
         }
 
         var playlist = await ParseListAsync();
-        return new List<StreamSpec>
+        return
-        {
+        [
             new()
             {
                 Url = ParserConfig.Url,
                 Playlist = playlist,
                 Extension = playlist.MediaInit != null ? "mp4" : "ts"
             }
-        };
+        ];
     }
 
     private async Task LoadM3u8FromUrlAsync(string url)
@@ -539,11 +521,10 @@ internal class HLSExtractor : IExtractor
         foreach (var l in lists)
         {
             var match = newStreams.Where(n => n.ToShortString() == l.ToShortString()).ToList();
-            if (match.Any())
+            if (match.Count == 0) continue;
-            {
+            
-                Logger.DebugMarkUp($"{l.Url} => {match.First().Url}");
+            Logger.DebugMarkUp($"{l.Url} => {match.First().Url}");
-                l.Url = match.First().Url;
+            l.Url = match.First().Url;
-            }
         }
     }
 
@@ -556,7 +537,7 @@ internal class HLSExtractor : IExtractor
                 // 直接重新加载m3u8
                 await LoadM3u8FromUrlAsync(lists[i].Url!);
             }
-            catch (HttpRequestException) when (MasterM3u8Flag == true)
+            catch (HttpRequestException) when (MasterM3u8Flag)
             {
                 Logger.WarnMarkUp("Can not load m3u8. Try refreshing url from master url...");
                 // 当前URL无法加载 尝试从Master链接中刷新URL

src/N_m3u8DL-RE.Parser/Extractor/IExtractor.cs

@@ -1,10 +1,5 @@
 using N_m3u8DL_RE.Parser.Config;
 using N_m3u8DL_RE.Common.Entity;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using N_m3u8DL_RE.Common.Enum;
 
 namespace N_m3u8DL_RE.Parser.Extractor;

src/N_m3u8DL-RE.Parser/Extractor/MSSExtractor.cs

@@ -6,14 +6,7 @@ using N_m3u8DL_RE.Parser.Config;
 using N_m3u8DL_RE.Parser.Constants;
 using N_m3u8DL_RE.Parser.Mp4;
 using N_m3u8DL_RE.Parser.Util;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Security.Cryptography;
-using System.Text;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
-using System.Xml;
 using System.Xml.Linq;
 
 namespace N_m3u8DL_RE.Parser.Extractor;
@@ -46,10 +39,7 @@ internal partial class MSSExtractor : IExtractor
     private void SetInitUrl()
     {
         this.IsmUrl = ParserConfig.Url ?? string.Empty;
-        if (!string.IsNullOrEmpty(ParserConfig.BaseUrl))
+        this.BaseUrl = !string.IsNullOrEmpty(ParserConfig.BaseUrl) ? ParserConfig.BaseUrl : this.IsmUrl;
-            this.BaseUrl = ParserConfig.BaseUrl;
-        else
-            this.BaseUrl = this.IsmUrl;
     }
 
     public Task<List<StreamSpec>> ExtractStreamsAsync(string rawText)
@@ -248,20 +238,17 @@ internal partial class MSSExtractor : IExtractor
         }
 
         // 为视频设置默认轨道
-        var aL = streamList.Where(s => s.MediaType == MediaType.AUDIO);
+        var aL = streamList.Where(s => s.MediaType == MediaType.AUDIO).ToList();
-        var sL = streamList.Where(s => s.MediaType == MediaType.SUBTITLES);
+        var sL = streamList.Where(s => s.MediaType == MediaType.SUBTITLES).ToList();
-        foreach (var item in streamList)
+        foreach (var item in streamList.Where(item => !string.IsNullOrEmpty(item.Resolution)))
         {
-            if (!string.IsNullOrEmpty(item.Resolution))
+            if (aL.Count != 0)
             {
-                if (aL.Any())
+                item.AudioId = aL.First().GroupId;
-                {
+            }
-                    item.AudioId = aL.First().GroupId;
+            if (sL.Count != 0)
-                }
+            {
-                if (sL.Any())
+                item.SubtitleId = sL.First().GroupId;
-                {
-                    item.SubtitleId = sL.First().GroupId;
-                }
             }
         }
 
@@ -318,22 +305,21 @@ internal partial class MSSExtractor : IExtractor
 
     private Task ProcessUrlAsync(List<StreamSpec> streamSpecs)
     {
-        for (int i = 0; i < streamSpecs.Count; i++)
+        foreach (var streamSpec in streamSpecs)
         {
-            var playlist = streamSpecs[i].Playlist;
+            var playlist = streamSpec.Playlist;
-            if (playlist != null)
+            if (playlist == null) continue;
+            
+            if (playlist.MediaInit != null)
             {
-                if (playlist.MediaInit != null)
+                playlist.MediaInit!.Url = PreProcessUrl(playlist.MediaInit!.Url);
+            }
+            for (var ii = 0; ii < playlist!.MediaParts.Count; ii++)
+            {
+                var part = playlist.MediaParts[ii];
+                foreach (var segment in part.MediaSegments)
                 {
-                    playlist.MediaInit!.Url = PreProcessUrl(playlist.MediaInit!.Url);
+                    segment.Url = PreProcessUrl(segment.Url);
-                }
-                for (int ii = 0; ii < playlist!.MediaParts.Count; ii++)
-                {
-                    var part = playlist.MediaParts[ii];
-                    for (int iii = 0; iii < part.MediaSegments.Count; iii++)
-                    {
-                        part.MediaSegments[iii].Url = PreProcessUrl(part.MediaSegments[iii].Url);
-                    }
                 }
             }
         }

src/N_m3u8DL-RE.Parser/Mp4/BinaryReader2.cs

@@ -1,70 +1,62 @@
-using System;
+namespace Mp4SubtitleParser;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
-namespace Mp4SubtitleParser
+// make BinaryReader in Big Endian
+class BinaryReader2 : BinaryReader
 {
-    // make BinaryReader in Big Endian
+    public BinaryReader2(System.IO.Stream stream) : base(stream) { }
-    class BinaryReader2 : BinaryReader
+
+    public bool HasMoreData()
     {
-        public BinaryReader2(System.IO.Stream stream) : base(stream) { }
+        return BaseStream.Position < BaseStream.Length;
-
-        public bool HasMoreData()
-        {
-            return BaseStream.Position < BaseStream.Length;
-        }
-
-        public long GetLength()
-        {
-            return BaseStream.Length;
-        }
-
-        public long GetPosition()
-        {
-            return BaseStream.Position;
-        }
-
-        public override int ReadInt32()
-        {
-            var data = base.ReadBytes(4);
-            if (BitConverter.IsLittleEndian)
-                Array.Reverse(data);
-            return BitConverter.ToInt32(data, 0);
-        }
-
-        public override short ReadInt16()
-        {
-            var data = base.ReadBytes(2);
-            if (BitConverter.IsLittleEndian)
-                Array.Reverse(data);
-            return BitConverter.ToInt16(data, 0);
-        }
-
-        public override long ReadInt64()
-        {
-            var data = base.ReadBytes(8);
-            if (BitConverter.IsLittleEndian)
-                Array.Reverse(data);
-            return BitConverter.ToInt64(data, 0);
-        }
-
-        public override uint ReadUInt32()
-        {
-            var data = base.ReadBytes(4);
-            if (BitConverter.IsLittleEndian)
-                Array.Reverse(data);
-            return BitConverter.ToUInt32(data, 0);
-        }
-
-        public override ulong ReadUInt64()
-        {
-            var data = base.ReadBytes(8);
-            if (BitConverter.IsLittleEndian)
-                Array.Reverse(data);
-            return BitConverter.ToUInt64(data, 0);
-        }
     }
-}
+
+    public long GetLength()
+    {
+        return BaseStream.Length;
+    }
+
+    public long GetPosition()
+    {
+        return BaseStream.Position;
+    }
+
+    public override int ReadInt32()
+    {
+        var data = base.ReadBytes(4);
+        if (BitConverter.IsLittleEndian)
+            Array.Reverse(data);
+        return BitConverter.ToInt32(data, 0);
+    }
+
+    public override short ReadInt16()
+    {
+        var data = base.ReadBytes(2);
+        if (BitConverter.IsLittleEndian)
+            Array.Reverse(data);
+        return BitConverter.ToInt16(data, 0);
+    }
+
+    public override long ReadInt64()
+    {
+        var data = base.ReadBytes(8);
+        if (BitConverter.IsLittleEndian)
+            Array.Reverse(data);
+        return BitConverter.ToInt64(data, 0);
+    }
+
+    public override uint ReadUInt32()
+    {
+        var data = base.ReadBytes(4);
+        if (BitConverter.IsLittleEndian)
+            Array.Reverse(data);
+        return BitConverter.ToUInt32(data, 0);
+    }
+
+    public override ulong ReadUInt64()
+    {
+        var data = base.ReadBytes(8);
+        if (BitConverter.IsLittleEndian)
+            Array.Reverse(data);
+        return BitConverter.ToUInt64(data, 0);
+    }
+}

src/N_m3u8DL-RE.Parser/Mp4/BinaryWriter2.cs

@@ -1,89 +1,83 @@
-using System;
+using System.Text;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
-namespace Mp4SubtitleParser
+namespace Mp4SubtitleParser;
+
+// make BinaryWriter in Big Endian
+class BinaryWriter2 : BinaryWriter
 {
-    // make BinaryWriter in Big Endian
+    private static bool IsLittleEndian = BitConverter.IsLittleEndian;
-    class BinaryWriter2 : BinaryWriter
+    public BinaryWriter2(System.IO.Stream stream) : base(stream) { }
+
+
+    public void WriteUInt(decimal n, int offset = 0)
     {
-        private static bool IsLittleEndian = BitConverter.IsLittleEndian;
+        var arr = BitConverter.GetBytes((uint)n);
-        public BinaryWriter2(System.IO.Stream stream) : base(stream) { }
+        if (IsLittleEndian)
-
+            Array.Reverse(arr);
-
+        if (offset != 0)
-        public void WriteUInt(decimal n, int offset = 0)
+            arr = arr[offset..];
-        {
+        BaseStream.Write(arr);
-            var arr = BitConverter.GetBytes((uint)n);
-            if (IsLittleEndian)
-                Array.Reverse(arr);
-            if (offset != 0)
-                arr = arr[offset..];
-            BaseStream.Write(arr);
-        }
-
-        public override void Write(string text)
-        {
-            BaseStream.Write(Encoding.ASCII.GetBytes(text));
-        }
-
-        public void WriteInt(decimal n, int offset = 0)
-        {
-            var arr = BitConverter.GetBytes((int)n);
-            if (IsLittleEndian)
-                Array.Reverse(arr);
-            if (offset != 0)
-                arr = arr[offset..];
-            BaseStream.Write(arr);
-        }
-
-        public void WriteULong(decimal n, int offset = 0)
-        {
-            var arr = BitConverter.GetBytes((ulong)n);
-            if (IsLittleEndian)
-                Array.Reverse(arr);
-            if (offset != 0)
-                arr = arr[offset..];
-            BaseStream.Write(arr);
-        }
-
-        public void WriteUShort(decimal n, int padding = 0)
-        {
-            var arr = BitConverter.GetBytes((ushort)n);
-            if (IsLittleEndian)
-                Array.Reverse(arr);
-            while (padding > 0)
-            {
-                arr = arr.Concat(new byte[] { 0x00 }).ToArray();
-                padding--;
-            }
-            BaseStream.Write(arr);
-        }
-
-        public void WriteShort(decimal n, int padding = 0)
-        {
-            var arr = BitConverter.GetBytes((short)n);
-            if (IsLittleEndian)
-                Array.Reverse(arr);
-            while (padding > 0)
-            {
-                arr = arr.Concat(new byte[] { 0x00 }).ToArray();
-                padding--;
-            }
-            BaseStream.Write(arr);
-        }
-
-        public void WriteByte(byte n, int padding = 0)
-        {
-            var arr = new byte[] { n };
-            while (padding > 0)
-            {
-                arr = arr.Concat(new byte[] { 0x00 }).ToArray();
-                padding--;
-            }
-            BaseStream.Write(arr);
-        }
     }
-}
+
+    public override void Write(string text)
+    {
+        BaseStream.Write(Encoding.ASCII.GetBytes(text));
+    }
+
+    public void WriteInt(decimal n, int offset = 0)
+    {
+        var arr = BitConverter.GetBytes((int)n);
+        if (IsLittleEndian)
+            Array.Reverse(arr);
+        if (offset != 0)
+            arr = arr[offset..];
+        BaseStream.Write(arr);
+    }
+
+    public void WriteULong(decimal n, int offset = 0)
+    {
+        var arr = BitConverter.GetBytes((ulong)n);
+        if (IsLittleEndian)
+            Array.Reverse(arr);
+        if (offset != 0)
+            arr = arr[offset..];
+        BaseStream.Write(arr);
+    }
+
+    public void WriteUShort(decimal n, int padding = 0)
+    {
+        var arr = BitConverter.GetBytes((ushort)n);
+        if (IsLittleEndian)
+            Array.Reverse(arr);
+        while (padding > 0)
+        {
+            arr = arr.Concat(new byte[] { 0x00 }).ToArray();
+            padding--;
+        }
+        BaseStream.Write(arr);
+    }
+
+    public void WriteShort(decimal n, int padding = 0)
+    {
+        var arr = BitConverter.GetBytes((short)n);
+        if (IsLittleEndian)
+            Array.Reverse(arr);
+        while (padding > 0)
+        {
+            arr = arr.Concat(new byte[] { 0x00 }).ToArray();
+            padding--;
+        }
+        BaseStream.Write(arr);
+    }
+
+    public void WriteByte(byte n, int padding = 0)
+    {
+        var arr = new byte[] { n };
+        while (padding > 0)
+        {
+            arr = arr.Concat(new byte[] { 0x00 }).ToArray();
+            padding--;
+        }
+        BaseStream.Write(arr);
+    }
+}

src/N_m3u8DL-RE.Parser/Mp4/MP4InitUtil.cs

@@ -1,5 +1,4 @@
 using N_m3u8DL_RE.Common.Util;
-using System.Security.Cryptography;
 
 namespace Mp4SubtitleParser
 {
@@ -11,10 +10,10 @@ namespace Mp4SubtitleParser
         public bool isMultiDRM;
     }
 
-    public class MP4InitUtil
+    public static class MP4InitUtil
     {
-        private static readonly byte[] SYSTEM_ID_WIDEVINE = { 0xED, 0xEF, 0x8B, 0xA9, 0x79, 0xD6, 0x4A, 0xCE, 0xA3, 0xC8, 0x27, 0xDC, 0xD5, 0x1D, 0x21, 0xED };
+        private static readonly byte[] SYSTEM_ID_WIDEVINE = [0xED, 0xEF, 0x8B, 0xA9, 0x79, 0xD6, 0x4A, 0xCE, 0xA3, 0xC8, 0x27, 0xDC, 0xD5, 0x1D, 0x21, 0xED];
-        private static readonly byte[] SYSTEM_ID_PLAYREADY = { 0x9A, 0x04, 0xF0, 0x79, 0x98, 0x40, 0x42, 0x86, 0xAB, 0x92, 0xE6, 0x5B, 0xE0, 0x88, 0x5F, 0x95 };
+        private static readonly byte[] SYSTEM_ID_PLAYREADY = [0x9A, 0x04, 0xF0, 0x79, 0x98, 0x40, 0x42, 0x86, 0xAB, 0x92, 0xE6, 0x5B, 0xE0, 0x88, 0x5F, 0x95];
 
         public static ParsedMP4Info ReadInit(byte[] data)
         {
@@ -28,22 +27,20 @@ namespace Mp4SubtitleParser
                 .Box("minf", MP4Parser.Children)
                 .Box("stbl", MP4Parser.Children)
                 .FullBox("stsd", MP4Parser.SampleDescription)
-                .FullBox("pssh", (box) =>
+                .FullBox("pssh", box =>
                 {
-                    if (!(box.Version == 0 || box.Version == 1))
+                    if (box.Version is not (0 or 1))
                         throw new Exception("PSSH version can only be 0 or 1");
                     var systemId = box.Reader.ReadBytes(16);
-                    if (SYSTEM_ID_WIDEVINE.SequenceEqual(systemId))
+                    if (!SYSTEM_ID_WIDEVINE.SequenceEqual(systemId)) return;
-                    {
+                    
-                        var dataSize = box.Reader.ReadUInt32();
+                    var dataSize = box.Reader.ReadUInt32();
-                        var psshData = box.Reader.ReadBytes((int)dataSize);
+                    var psshData = box.Reader.ReadBytes((int)dataSize);
-                        info.PSSH = Convert.ToBase64String(psshData);
+                    info.PSSH = Convert.ToBase64String(psshData);
-                        if (info.KID == "00000000000000000000000000000000")
+                    if (info.KID != "00000000000000000000000000000000") return;
-                        {
+                    
-                            info.KID = HexUtil.BytesToHex(psshData[2..18]).ToLower();
+                    info.KID = HexUtil.BytesToHex(psshData[2..18]).ToLower();
-                            info.isMultiDRM = true;
+                    info.isMultiDRM = true;
-                        }
-                    }
                 })
                 .FullBox("encv", MP4Parser.AllData(data => ReadBox(data, info)))
                 .FullBox("enca", MP4Parser.AllData(data => ReadBox(data, info)))
@@ -57,11 +54,11 @@ namespace Mp4SubtitleParser
         private static void ReadBox(byte[] data, ParsedMP4Info info)
         {
             // find schm 
-            var schmBytes = new byte[4] { 0x73, 0x63, 0x68, 0x6d };
+            byte[] schmBytes = [0x73, 0x63, 0x68, 0x6d];
             var schmIndex = 0;
-            for (int i = 0; i < data.Length - 4; i++) 
+            for (var i = 0; i < data.Length - 4; i++) 
             {
-                if (new byte[4] { data[i], data[i + 1], data[i + 2], data[i + 3] }.SequenceEqual(schmBytes))
+                if (new[] { data[i], data[i + 1], data[i + 2], data[i + 3] }.SequenceEqual(schmBytes))
                 {
                     schmIndex = i;
                     break;
@@ -75,11 +72,11 @@ namespace Mp4SubtitleParser
             // if (info.Scheme != "cenc") return;
 
             // find KID
-            var tencBytes = new byte[4] { 0x74, 0x65, 0x6E, 0x63 };
+            byte[] tencBytes = [0x74, 0x65, 0x6E, 0x6];
             var tencIndex = -1;
             for (int i = 0; i < data.Length - 4; i++)
             {
-                if (new byte[4] { data[i], data[i + 1], data[i + 2], data[i + 3] }.SequenceEqual(tencBytes))
+                if (new[] { data[i], data[i + 1], data[i + 2], data[i + 3] }.SequenceEqual(tencBytes))
                 {
                     tencIndex = i;
                     break;

src/N_m3u8DL-RE.Parser/Mp4/MP4Parser.cs

@@ -9,12 +9,12 @@ namespace Mp4SubtitleParser
 {
     class ParsedBox
     {
-        public MP4Parser Parser { get; set; }
+        public required MP4Parser Parser { get; set; }
         public bool PartialOkay { get; set; }
         public long Start { get; set; }
         public uint Version { get; set; } = 1000;
         public uint Flags { get; set; } = 1000;
-        public BinaryReader2 Reader { get; set; }
+        public required BinaryReader2 Reader { get; set; }
         public bool Has64BitSize { get; set; }
     }
 
@@ -28,7 +28,7 @@ namespace Mp4SubtitleParser
     class TRUN
     {
         public uint SampleCount { get; set; }
-        public List<Sample> SampleData { get; set; } = new List<Sample>();
+        public List<Sample> SampleData { get; set; } = [];
     }
 
     class Sample
@@ -55,7 +55,7 @@ namespace Mp4SubtitleParser
 
         public static BoxHandler AllData(DataHandler handler)
         {
-            return (box) =>
+            return box =>
             {
                 var all = box.Reader.GetLength() - box.Reader.GetPosition();
                 handler(box.Reader.ReadBytes((int)all));
@@ -161,7 +161,7 @@ namespace Mp4SubtitleParser
                 }
 
                 int payloadSize = (int)(end - reader.GetPosition());
-                var payload = (payloadSize > 0) ? reader.ReadBytes(payloadSize) : new byte[0];
+                var payload = (payloadSize > 0) ? reader.ReadBytes(payloadSize) : [];
                 var box = new ParsedBox()
                 {
                     Parser = this,

src/N_m3u8DL-RE.Parser/Mp4/MP4TtmlUtil.cs

@@ -3,75 +3,229 @@ using System.Text;
 using System.Text.RegularExpressions;
 using System.Xml;
 
-namespace Mp4SubtitleParser
+namespace Mp4SubtitleParser;
+
+class SubEntity
 {
-    class SubEntity
+    public required string Begin { get; set; }
+    public required string End { get; set; }
+    public required string Region { get; set; }
+    public List<XmlElement> Contents { get; set; } = [];
+    public List<string> ContentStrings { get; set; } = [];
+
+    public override bool Equals(object? obj)
     {
-        public string Begin { get; set; }
+        return obj is SubEntity entity &&
-        public string End { get; set; }
+               Begin == entity.Begin &&
-        public string Region { get; set; }
+               End == entity.End &&
-        public List<XmlElement> Contents { get; set; } = new();
+               Region == entity.Region &&
-        public List<string> ContentStrings { get; set; } = new();
+               ContentStrings.SequenceEqual(entity.ContentStrings);
-
-        public override bool Equals(object? obj)
-        {
-            return obj is SubEntity entity &&
-                   Begin == entity.Begin &&
-                   End == entity.End &&
-                   Region == entity.Region &&
-                   ContentStrings.SequenceEqual(entity.ContentStrings);
-        }
-
-        public override int GetHashCode()
-        {
-            return HashCode.Combine(Begin, End, Region, ContentStrings);
-        }
     }
 
-    public partial class MP4TtmlUtil
+    public override int GetHashCode()
     {
-        [GeneratedRegex(" \\w+:\\w+=\\\"[^\\\"]*\\\"")]
+        return HashCode.Combine(Begin, End, Region, ContentStrings);
-        private static partial Regex AttrRegex();
+    }
-        [GeneratedRegex("<p.*?>(.+?)<\\/p>")]
+}
-        private static partial Regex LabelFixRegex();
-        [GeneratedRegex("\\<tt[\\s\\S]*?\\<\\/tt\\>")]
-        private static partial Regex MultiElementsFixRegex();
-        [GeneratedRegex("\\<smpte:image.*xml:id=\\\"(.*?)\\\".*\\>([\\s\\S]*?)<\\/smpte:image>")]
-        private static partial Regex ImageRegex();
 
-        public static bool CheckInit(byte[] data)
+public static partial class MP4TtmlUtil
+{
+    [GeneratedRegex(" \\w+:\\w+=\\\"[^\\\"]*\\\"")]
+    private static partial Regex AttrRegex();
+    [GeneratedRegex("<p.*?>(.+?)<\\/p>")]
+    private static partial Regex LabelFixRegex();
+    [GeneratedRegex(@"\<tt[\s\S]*?\<\/tt\>")]
+    private static partial Regex MultiElementsFixRegex();
+    [GeneratedRegex("\\<smpte:image.*xml:id=\\\"(.*?)\\\".*\\>([\\s\\S]*?)<\\/smpte:image>")]
+    private static partial Regex ImageRegex();
+
+    public static bool CheckInit(byte[] data)
+    {
+        bool sawSTPP = false;
+
+        // parse init
+        new MP4Parser()
+            .Box("moov", MP4Parser.Children)
+            .Box("trak", MP4Parser.Children)
+            .Box("mdia", MP4Parser.Children)
+            .Box("minf", MP4Parser.Children)
+            .Box("stbl", MP4Parser.Children)
+            .FullBox("stsd", MP4Parser.SampleDescription)
+            .Box("stpp", box => {
+                sawSTPP = true;
+            })
+            .Parse(data);
+
+        return sawSTPP;
+    }
+
+    private static string ShiftTime(string xmlSrc, long segTimeMs, int index)
+    {
+        string Add(string xmlTime)
         {
-            bool sawSTPP = false;
+            var dt = DateTime.ParseExact(xmlTime, "HH:mm:ss.fff", System.Globalization.CultureInfo.InvariantCulture);
-
+            var ts = TimeSpan.FromMilliseconds(dt.TimeOfDay.TotalMilliseconds + segTimeMs * index);
-            // parse init
+            return $"{ts.Hours:00}:{ts.Minutes:00}:{ts.Seconds:00}.{ts.Milliseconds:000}";
-            new MP4Parser()
-                .Box("moov", MP4Parser.Children)
-                .Box("trak", MP4Parser.Children)
-                .Box("mdia", MP4Parser.Children)
-                .Box("minf", MP4Parser.Children)
-                .Box("stbl", MP4Parser.Children)
-                .FullBox("stsd", MP4Parser.SampleDescription)
-                .Box("stpp", (box) => {
-                    sawSTPP = true;
-                })
-                .Parse(data);
-
-            return sawSTPP;
         }
 
-        private static string ShiftTime(string xmlSrc, long segTimeMs, int index)
+        if (!xmlSrc.Contains("<tt") || !xmlSrc.Contains("<head>")) return xmlSrc;
+        var xmlDoc = new XmlDocument();
+        XmlNamespaceManager? nsMgr = null;
+        xmlDoc.LoadXml(xmlSrc);
+        var ttNode = xmlDoc.LastChild;
+        if (nsMgr == null)
         {
-            string Add(string xmlTime)
+            var ns = ((XmlElement)ttNode!).GetAttribute("xmlns");
-            {
+            nsMgr = new XmlNamespaceManager(xmlDoc.NameTable);
-                var dt = DateTime.ParseExact(xmlTime, "HH:mm:ss.fff", System.Globalization.CultureInfo.InvariantCulture);
+            nsMgr.AddNamespace("ns", ns);
-                var ts = TimeSpan.FromMilliseconds(dt.TimeOfDay.TotalMilliseconds + segTimeMs * index);
+        }
-                return string.Format("{0:00}:{1:00}:{2:00}.{3:000}", ts.Hours, ts.Minutes, ts.Seconds, ts.Milliseconds);
-            }
 
-            if (!xmlSrc.Contains("<tt") || !xmlSrc.Contains("<head>")) return xmlSrc;
+        var bodyNode = ttNode!.SelectSingleNode("ns:body", nsMgr);
-            var xmlDoc = new XmlDocument();
+        if (bodyNode == null)
-            XmlNamespaceManager? nsMgr = null;
+            return xmlSrc;
-            xmlDoc.LoadXml(xmlSrc);
+
+        var _div = bodyNode.SelectSingleNode("ns:div", nsMgr);
+        // Parse <p> label
+        foreach (XmlElement _p in _div!.SelectNodes("ns:p", nsMgr)!)
+        {
+            var _begin = _p.GetAttribute("begin");
+            var _end = _p.GetAttribute("end");
+            // Handle namespace
+            foreach (XmlAttribute attr in _p.Attributes)
+            {
+                if (attr.LocalName == "begin") _begin = attr.Value;
+                else if (attr.LocalName == "end") _end = attr.Value;
+            }
+            _p.SetAttribute("begin", Add(_begin));
+            _p.SetAttribute("end", Add(_end));
+            // Console.WriteLine($"{_begin} {_p.GetAttribute("begin")}");
+            // Console.WriteLine($"{_end} {_p.GetAttribute("begin")}");
+        }
+
+        return xmlDoc.OuterXml;
+    }
+
+    private static string GetTextFromElement(XmlElement node)
+    {
+        var sb = new StringBuilder();
+        foreach (XmlNode item in node.ChildNodes)
+        {
+            if (item.NodeType == XmlNodeType.Text)
+            {
+                sb.Append(item.InnerText.Trim());
+            }
+            else if(item is { NodeType: XmlNodeType.Element, Name: "br" })
+            {
+                sb.AppendLine();
+            }
+        }
+        return sb.ToString();
+    }
+
+    private static List<string> SplitMultipleRootElements(string xml)
+    {
+        return !MultiElementsFixRegex().IsMatch(xml) ? [] : MultiElementsFixRegex().Matches(xml).Select(m => m.Value).ToList();
+    }
+
+    public static WebVttSub ExtractFromMp4(string item, long segTimeMs, long baseTimestamp = 0L)
+    {
+        return ExtractFromMp4s([item], segTimeMs, baseTimestamp);
+    }
+
+    private static WebVttSub ExtractFromMp4s(IEnumerable<string> items, long segTimeMs, long baseTimestamp = 0L)
+    {
+        // read ttmls
+        List<string> xmls = [];
+        int segIndex = 0;
+        foreach (var item in items)
+        {
+            var dataSeg = File.ReadAllBytes(item);
+
+            var sawMDAT = false;
+            // parse media
+            new MP4Parser()
+                .Box("mdat", MP4Parser.AllData(data =>
+                {
+                    sawMDAT = true;
+                    // Join this to any previous payload, in case the mp4 has multiple
+                    // mdats.
+                    if (segTimeMs != 0)
+                    {
+                        var datas = SplitMultipleRootElements(Encoding.UTF8.GetString(data));
+                        foreach (var item in datas)
+                        {
+                            xmls.Add(ShiftTime(item, segTimeMs, segIndex));
+                        }
+                    }
+                    else
+                    {
+                        var datas = SplitMultipleRootElements(Encoding.UTF8.GetString(data));
+                        xmls.AddRange(datas);
+                    }
+                }))
+                .Parse(dataSeg,/* partialOkay= */ false);
+            segIndex++;
+        }
+
+        return ExtractSub(xmls, baseTimestamp);
+    }
+
+    public static WebVttSub ExtractFromTTML(string item, long segTimeMs, long baseTimestamp = 0L)
+    {
+        return ExtractFromTTMLs([item], segTimeMs, baseTimestamp);
+    }
+
+    public static WebVttSub ExtractFromTTMLs(IEnumerable<string> items, long segTimeMs, long baseTimestamp = 0L)
+    {
+        // read ttmls
+        List<string> xmls = [];
+        int segIndex = 0;
+        foreach (var item in items)
+        {
+            var xml = File.ReadAllText(item);
+            xmls.Add(segTimeMs != 0 ? ShiftTime(xml, segTimeMs, segIndex) : xml);
+            segIndex++;
+        }
+
+        return ExtractSub(xmls, baseTimestamp);
+    }
+
+    private static WebVttSub ExtractSub(List<string> xmls, long baseTimestamp)
+    {
+        // parsing
+        var xmlDoc = new XmlDocument();
+        var finalSubs = new List<SubEntity>();
+        XmlNode? headNode = null;
+        XmlNamespaceManager? nsMgr = null;
+        var regex = LabelFixRegex();
+        var attrRegex = AttrRegex();
+        foreach (var item in xmls)
+        {
+            var xmlContent = item;
+            if (!xmlContent.Contains("<tt")) continue;
+
+            // fix non-standard xml 
+            var xmlContentFix = xmlContent;
+            if (regex.IsMatch(xmlContent))
+            {
+                foreach (Match m in regex.Matches(xmlContentFix))
+                {
+                    try
+                    {
+                        var inner = m.Groups[1].Value;
+                        if (attrRegex.IsMatch(inner))
+                        {
+                            inner = attrRegex.Replace(inner, "");
+                        }
+                        new XmlDocument().LoadXml($"<p>{inner}</p>");
+                    }
+                    catch (Exception)
+                    {
+                        xmlContentFix = xmlContentFix.Replace(m.Groups[1].Value, System.Web.HttpUtility.HtmlEncode(m.Groups[1].Value));
+                    }
+                }
+            }
+            xmlDoc.LoadXml(xmlContentFix);
             var ttNode = xmlDoc.LastChild;
             if (nsMgr == null)
             {
@@ -79,306 +233,142 @@ namespace Mp4SubtitleParser
                 nsMgr = new XmlNamespaceManager(xmlDoc.NameTable);
                 nsMgr.AddNamespace("ns", ns);
             }
+            if (headNode == null)
+                headNode = ttNode!.SelectSingleNode("ns:head", nsMgr);
 
             var bodyNode = ttNode!.SelectSingleNode("ns:body", nsMgr);
             if (bodyNode == null)
-                return xmlSrc;
+                continue;
 
             var _div = bodyNode.SelectSingleNode("ns:div", nsMgr);
+            if (_div == null)
+                continue;
+
+
+            // PNG Subs
+            var imageDic = new Dictionary<string, string>(); // id, Base64
+            if (ImageRegex().IsMatch(xmlDoc.InnerXml))
+            {
+                foreach (Match img in ImageRegex().Matches(xmlDoc.InnerXml))
+                {
+                    imageDic.Add(img.Groups[1].Value.Trim(), img.Groups[2].Value.Trim());
+                }
+            }
+
+            // convert <div> to <p>
+            if (_div!.SelectNodes("ns:p", nsMgr) == null || _div!.SelectNodes("ns:p", nsMgr)!.Count == 0)
+            {
+                foreach (XmlElement _tDiv in bodyNode.SelectNodes("ns:div", nsMgr)!)
+                {
+                    var _p = xmlDoc.CreateDocumentFragment();
+                    _p.InnerXml = _tDiv.OuterXml.Replace("<div ", "<p ").Replace("</div>", "</p>");
+                    _div.AppendChild(_p);
+                }
+            }
+
             // Parse <p> label
             foreach (XmlElement _p in _div!.SelectNodes("ns:p", nsMgr)!)
             {
                 var _begin = _p.GetAttribute("begin");
                 var _end = _p.GetAttribute("end");
+                var _region = _p.GetAttribute("region");
+                var _bgImg = _p.GetAttribute("smpte:backgroundImage");
                 // Handle namespace
                 foreach (XmlAttribute attr in _p.Attributes)
                 {
                     if (attr.LocalName == "begin") _begin = attr.Value;
                     else if (attr.LocalName == "end") _end = attr.Value;
+                    else if (attr.LocalName == "region") _region = attr.Value;
                 }
-                _p.SetAttribute("begin", Add(_begin));
+                var sub = new SubEntity
-                _p.SetAttribute("end", Add(_end));
-                // Console.WriteLine($"{_begin} {_p.GetAttribute("begin")}");
-                // Console.WriteLine($"{_end} {_p.GetAttribute("begin")}");
-            }
-
-            return xmlDoc.OuterXml;
-        }
-
-        private static string GetTextFromElement(XmlElement node)
-        {
-            var sb = new StringBuilder();
-            foreach (XmlNode item in node.ChildNodes)
-            {
-                if (item.NodeType == XmlNodeType.Text)
                 {
-                    sb.Append(item.InnerText.Trim());
+                    Begin = _begin,
-                }
+                    End = _end,
-                else if(item.NodeType == XmlNodeType.Element && item.Name == "br")
+                    Region = _region
+                };
+
+                if (string.IsNullOrEmpty(_bgImg))
                 {
-                    sb.AppendLine();
+                    var _spans = _p.ChildNodes;
-                }
+                    // Collect <span>
-            }
+                    foreach (XmlNode _node in _spans)
-            return sb.ToString();
-        }
-
-        public static List<string> SplitMultipleRootElements(string xml)
-        {
-            if (!MultiElementsFixRegex().IsMatch(xml)) return new List<string>();
-            return MultiElementsFixRegex().Matches(xml).Select(m => m.Value).ToList();
-        }
-
-        public static WebVttSub ExtractFromMp4(string item, long segTimeMs, long baseTimestamp = 0L)
-        {
-            return ExtractFromMp4s(new string[] { item }, segTimeMs, baseTimestamp);
-        }
-
-        public static WebVttSub ExtractFromMp4s(IEnumerable<string> items, long segTimeMs, long baseTimestamp = 0L)
-        {
-            // read ttmls
-            List<string> xmls = new List<string>();
-            int segIndex = 0;
-            foreach (var item in items)
-            {
-                var dataSeg = File.ReadAllBytes(item);
-
-                var sawMDAT = false;
-                // parse media
-                new MP4Parser()
-                    .Box("mdat", MP4Parser.AllData((data) =>
                     {
-                        sawMDAT = true;
+                        if (_node.NodeType == XmlNodeType.Element)
-                        // Join this to any previous payload, in case the mp4 has multiple
-                        // mdats.
-                        if (segTimeMs != 0)
                         {
-                            var datas = SplitMultipleRootElements(Encoding.UTF8.GetString(data));
+                            var _span = (XmlElement)_node;
-                            foreach (var item in datas)
+                            if (string.IsNullOrEmpty(_span.InnerText))
-                            {
+                                continue;
-                                xmls.Add(ShiftTime(item, segTimeMs, segIndex));
+                            sub.Contents.Add(_span);
-                            }
+                            sub.ContentStrings.Add(_span.OuterXml);
                         }
-                        else
+                        else if (_node.NodeType == XmlNodeType.Text)
-                        {
-                            var datas = SplitMultipleRootElements(Encoding.UTF8.GetString(data));
-                            xmls.AddRange(datas);
-                        }
-                    }))
-                    .Parse(dataSeg,/* partialOkay= */ false);
-                segIndex++;
-            }
-
-            return ExtractSub(xmls, baseTimestamp);
-        }
-
-        public static WebVttSub ExtractFromTTML(string item, long segTimeMs, long baseTimestamp = 0L)
-        {
-            return ExtractFromTTMLs(new string[] { item }, segTimeMs, baseTimestamp);
-        }
-
-        public static WebVttSub ExtractFromTTMLs(IEnumerable<string> items, long segTimeMs, long baseTimestamp = 0L)
-        {
-            // read ttmls
-            List<string> xmls = new List<string>();
-            int segIndex = 0;
-            foreach (var item in items)
-            {
-                var xml = File.ReadAllText(item);
-                if (segTimeMs != 0)
-                {
-                    xmls.Add(ShiftTime(xml, segTimeMs, segIndex));
-                }
-                else
-                {
-                    xmls.Add(xml);
-                }
-                segIndex++;
-            }
-
-            return ExtractSub(xmls, baseTimestamp);
-        }
-
-        private static WebVttSub ExtractSub(List<string> xmls, long baseTimestamp)
-        {
-            // parsing
-            var xmlDoc = new XmlDocument();
-            var finalSubs = new List<SubEntity>();
-            XmlNode? headNode = null;
-            XmlNamespaceManager? nsMgr = null;
-            var regex = LabelFixRegex();
-            var attrRegex = AttrRegex();
-            foreach (var item in xmls)
-            {
-                var xmlContent = item;
-                if (!xmlContent.Contains("<tt")) continue;
-
-                // fix non-standard xml 
-                var xmlContentFix = xmlContent;
-                if (regex.IsMatch(xmlContent))
-                {
-                    foreach (Match m in regex.Matches(xmlContentFix))
-                    {
-                        try
-                        {
-                            var inner = m.Groups[1].Value;
-                            if (attrRegex.IsMatch(inner))
-                            {
-                                inner = attrRegex.Replace(inner, "");
-                            }
-                            new XmlDocument().LoadXml($"<p>{inner}</p>");
-                        }
-                        catch (Exception)
-                        {
-                            xmlContentFix = xmlContentFix.Replace(m.Groups[1].Value, System.Web.HttpUtility.HtmlEncode(m.Groups[1].Value));
-                        }
-                    }
-                }
-                xmlDoc.LoadXml(xmlContentFix);
-                var ttNode = xmlDoc.LastChild;
-                if (nsMgr == null)
-                {
-                    var ns = ((XmlElement)ttNode!).GetAttribute("xmlns");
-                    nsMgr = new XmlNamespaceManager(xmlDoc.NameTable);
-                    nsMgr.AddNamespace("ns", ns);
-                }
-                if (headNode == null)
-                    headNode = ttNode!.SelectSingleNode("ns:head", nsMgr);
-
-                var bodyNode = ttNode!.SelectSingleNode("ns:body", nsMgr);
-                if (bodyNode == null)
-                    continue;
-
-                var _div = bodyNode.SelectSingleNode("ns:div", nsMgr);
-                if (_div == null)
-                    continue;
-
-
-                // PNG Subs
-                var imageDic = new Dictionary<string, string>(); // id, Base64
-                if (ImageRegex().IsMatch(xmlDoc.InnerXml))
-                {
-                    foreach (Match img in ImageRegex().Matches(xmlDoc.InnerXml))
-                    {
-                        imageDic.Add(img.Groups[1].Value.Trim(), img.Groups[2].Value.Trim());
-                    }
-                }
-
-                // convert <div> to <p>
-                if (_div!.SelectNodes("ns:p", nsMgr) == null || _div!.SelectNodes("ns:p", nsMgr)!.Count == 0)
-                {
-                    foreach (XmlElement _tDiv in bodyNode.SelectNodes("ns:div", nsMgr)!)
-                    {
-                        var _p = xmlDoc.CreateDocumentFragment();
-                        _p.InnerXml = _tDiv.OuterXml.Replace("<div ", "<p ").Replace("</div>", "</p>");
-                        _div.AppendChild(_p);
-                    }
-                }
-
-                // Parse <p> label
-                foreach (XmlElement _p in _div!.SelectNodes("ns:p", nsMgr)!)
-                {
-                    var _begin = _p.GetAttribute("begin");
-                    var _end = _p.GetAttribute("end");
-                    var _region = _p.GetAttribute("region");
-                    var _bgImg = _p.GetAttribute("smpte:backgroundImage");
-                    // Handle namespace
-                    foreach (XmlAttribute attr in _p.Attributes)
-                    {
-                        if (attr.LocalName == "begin") _begin = attr.Value;
-                        else if (attr.LocalName == "end") _end = attr.Value;
-                        else if (attr.LocalName == "region") _region = attr.Value;
-                    }
-                    var sub = new SubEntity
-                    {
-                        Begin = _begin,
-                        End = _end,
-                        Region = _region
-                    };
-
-                    if (string.IsNullOrEmpty(_bgImg))
-                    {
-                        var _spans = _p.ChildNodes;
-                        // Collect <span>
-                        foreach (XmlNode _node in _spans)
-                        {
-                            if (_node.NodeType == XmlNodeType.Element)
-                            {
-                                var _span = (XmlElement)_node;
-                                if (string.IsNullOrEmpty(_span.InnerText))
-                                    continue;
-                                sub.Contents.Add(_span);
-                                sub.ContentStrings.Add(_span.OuterXml);
-                            }
-                            else if (_node.NodeType == XmlNodeType.Text)
-                            {
-                                var _span = new XmlDocument().CreateElement("span");
-                                _span.InnerText = _node.Value!;
-                                sub.Contents.Add(_span);
-                                sub.ContentStrings.Add(_span.OuterXml);
-                            }
-                        }
-                    }
-                    else
-                    {
-                        var id = _bgImg.Replace("#", "");
-                        if (imageDic.ContainsKey(id))
                         {
                             var _span = new XmlDocument().CreateElement("span");
-                            _span.InnerText = $"Base64::{imageDic[id]}";
+                            _span.InnerText = _node.Value!;
                             sub.Contents.Add(_span);
                             sub.ContentStrings.Add(_span.OuterXml);
                         }
                     }
-                    
-                    // Check if one <p> has been splitted
-                    var index = finalSubs.FindLastIndex(s => s.End == _begin && s.Region == _region && s.ContentStrings.SequenceEqual(sub.ContentStrings));
-                    // Skip empty lines
-                    if (sub.ContentStrings.Count > 0)
-                    {
-                        // Extend <p> duration
-                        if (index != -1)
-                            finalSubs[index].End = sub.End;
-                        else if (!finalSubs.Contains(sub))
-                            finalSubs.Add(sub);
-                    }
                 }
-            }
+                else
-
-
-            var dic = new Dictionary<string, string>();
-            foreach (var sub in finalSubs)
-            {
-                var key = $"{sub.Begin} --> {sub.End}";
-                foreach (var item in sub.Contents)
                 {
-                    if (dic.ContainsKey(key))
+                    var id = _bgImg.Replace("#", "");
+                    if (imageDic.TryGetValue(id, out var value))
                     {
-                        if (item.GetAttribute("tts:fontStyle") == "italic" || item.GetAttribute("tts:fontStyle") == "oblique")
+                        var _span = new XmlDocument().CreateElement("span");
-                            dic[key] = $"{dic[key]}\r\n<i>{GetTextFromElement(item)}</i>";
+                        _span.InnerText = $"Base64::{value}";
-                        else
+                        sub.Contents.Add(_span);
-                            dic[key] = $"{dic[key]}\r\n{GetTextFromElement(item)}";
+                        sub.ContentStrings.Add(_span.OuterXml);
-                    }
-                    else
-                    {
-                        if (item.GetAttribute("tts:fontStyle") == "italic" || item.GetAttribute("tts:fontStyle") == "oblique")
-                            dic.Add(key, $"<i>{GetTextFromElement(item)}</i>");
-                        else
-                            dic.Add(key, GetTextFromElement(item));
                     }
                 }
+                    
+                // Check if one <p> has been splitted
+                var index = finalSubs.FindLastIndex(s => s.End == _begin && s.Region == _region && s.ContentStrings.SequenceEqual(sub.ContentStrings));
+                // Skip empty lines
+                if (sub.ContentStrings.Count <= 0)
+                    continue;
+                // Extend <p> duration
+                if (index != -1)
+                    finalSubs[index].End = sub.End;
+                else if (!finalSubs.Contains(sub))
+                    finalSubs.Add(sub);
             }
-
-
-            var vtt = new StringBuilder();
-            vtt.AppendLine("WEBVTT");
-            foreach (var item in dic)
-            {
-                vtt.AppendLine(item.Key);
-                vtt.AppendLine(item.Value);
-                vtt.AppendLine();
-            }
-
-            return WebVttSub.Parse(vtt.ToString(), baseTimestamp);
         }
+
+
+        var dic = new Dictionary<string, string>();
+        foreach (var sub in finalSubs)
+        {
+            var key = $"{sub.Begin} --> {sub.End}";
+            foreach (var item in sub.Contents)
+            {
+                if (dic.ContainsKey(key))
+                {
+                    if (item.GetAttribute("tts:fontStyle") == "italic" || item.GetAttribute("tts:fontStyle") == "oblique")
+                        dic[key] = $"{dic[key]}\r\n<i>{GetTextFromElement(item)}</i>";
+                    else
+                        dic[key] = $"{dic[key]}\r\n{GetTextFromElement(item)}";
+                }
+                else
+                {
+                    if (item.GetAttribute("tts:fontStyle") == "italic" || item.GetAttribute("tts:fontStyle") == "oblique")
+                        dic.Add(key, $"<i>{GetTextFromElement(item)}</i>");
+                    else
+                        dic.Add(key, GetTextFromElement(item));
+                }
+            }
+        }
+
+
+        var vtt = new StringBuilder();
+        vtt.AppendLine("WEBVTT");
+        foreach (var item in dic)
+        {
+            vtt.AppendLine(item.Key);
+            vtt.AppendLine(item.Value);
+            vtt.AppendLine();
+        }
+
+        return WebVttSub.Parse(vtt.ToString(), baseTimestamp);
     }
-}
+}

src/N_m3u8DL-RE.Parser/Mp4/MP4VttUtil.cs

@@ -3,7 +3,7 @@ using System.Text;
 
 namespace Mp4SubtitleParser;
 
-public class MP4VttUtil
+public static class MP4VttUtil
 {
     public static (bool, uint) CheckInit(byte[] data)
     {
@@ -15,16 +15,16 @@ public class MP4VttUtil
             .Box("moov", MP4Parser.Children)
             .Box("trak", MP4Parser.Children)
             .Box("mdia", MP4Parser.Children)
-            .FullBox("mdhd", (box) =>
+            .FullBox("mdhd", box =>
             {
-                if (!(box.Version == 0 || box.Version == 1))
+                if (box.Version is not (0 or 1))
                     throw new Exception("MDHD version can only be 0 or 1");
                 timescale = MP4Parser.ParseMDHD(box.Reader, box.Version);
             })
             .Box("minf", MP4Parser.Children)
             .Box("stbl", MP4Parser.Children)
             .FullBox("stsd", MP4Parser.SampleDescription)
-            .Box("wvtt", (box) => {
+            .Box("wvtt", _ => {
                 // A valid vtt init segment, though we have no actual subtitles yet.
                 sawWVTT = true;
             })
@@ -38,7 +38,7 @@ public class MP4VttUtil
         if (timescale == 0)
             throw new Exception("Missing timescale for VTT content!");
 
-        List<SubCue> cues = new();
+        List<SubCue> cues = [];
 
         foreach (var item in files)
         {
@@ -50,27 +50,27 @@ public class MP4VttUtil
             byte[]? rawPayload = null;
             ulong baseTime = 0;
             ulong defaultDuration = 0;
-            List<Sample> presentations = new();
+            List<Sample> presentations = [];
 
 
             // parse media
             new MP4Parser()
                 .Box("moof", MP4Parser.Children)
                 .Box("traf", MP4Parser.Children)
-                .FullBox("tfdt", (box) =>
+                .FullBox("tfdt", box =>
                 {
                     sawTFDT = true;
-                    if (!(box.Version == 0 || box.Version == 1))
+                    if (box.Version is not (0 or 1))
                         throw new Exception("TFDT version can only be 0 or 1");
                     baseTime = MP4Parser.ParseTFDT(box.Reader, box.Version);
                 })
-                .FullBox("tfhd", (box) =>
+                .FullBox("tfhd", box =>
                 {
                     if (box.Flags == 1000)
                         throw new Exception("A TFHD box should have a valid flags value");
                     defaultDuration = MP4Parser.ParseTFHD(box.Reader, box.Flags).DefaultSampleDuration;
                 })
-                .FullBox("trun", (box) =>
+                .FullBox("trun", box =>
                 {
                     sawTRUN = true;
                     if (box.Version == 1000)
@@ -79,7 +79,7 @@ public class MP4VttUtil
                         throw new Exception("A TRUN box should have a valid flags value");
                     presentations = MP4Parser.ParseTRUN(box.Reader, box.Version, box.Flags).SampleData;
                 })
-                .Box("mdat", MP4Parser.AllData((data) =>
+                .Box("mdat", MP4Parser.AllData(data =>
                 {
                     if (sawMDAT)
                         throw new Exception("VTT cues in mp4 with multiple MDAT are not currently supported");
@@ -139,8 +139,6 @@ public class MP4VttUtil
                     {
                         if (payload != null)
                         {
-                            if (timescale == 0)
-                                throw new Exception("Timescale should not be zero!");
                             var cue = ParseVTTC(
                                 payload,
                                 0 + (double)startTime / timescale,
@@ -192,15 +190,15 @@ public class MP4VttUtil
         string id = string.Empty;
         string settings = string.Empty;
         new MP4Parser()
-            .Box("payl", MP4Parser.AllData((data) =>
+            .Box("payl", MP4Parser.AllData(data =>
             {
                 payload = Encoding.UTF8.GetString(data);
             }))
-            .Box("iden", MP4Parser.AllData((data) =>
+            .Box("iden", MP4Parser.AllData(data =>
             {
                 id = Encoding.UTF8.GetString(data);
             }))
-            .Box("sttg", MP4Parser.AllData((data) =>
+            .Box("sttg", MP4Parser.AllData(data =>
             {
                 settings = Encoding.UTF8.GetString(data);
             }))

src/N_m3u8DL-RE.Parser/Mp4/MSSMoovProcessor.cs

@@ -13,7 +13,7 @@ namespace N_m3u8DL_RE.Parser.Mp4;
 
 public partial class MSSMoovProcessor
 {
-    [GeneratedRegex("\\<KID\\>(.*?)\\<")]
+    [GeneratedRegex(@"\<KID\>(.*?)\<")]
     private static partial Regex KIDRegex();
 
     private static string StartCode = "00000001";
@@ -23,7 +23,7 @@ public partial class MSSMoovProcessor
     private string CodecPrivateData;
     private int Timesacle;
     private long Duration;
-    private string Language { get => StreamSpec.Language ?? "und"; }
+    private string Language => StreamSpec.Language ?? "und";
     private int Width => int.Parse((StreamSpec.Resolution ?? "0x0").Split('x').First());
     private int Height => int.Parse((StreamSpec.Resolution ?? "0x0").Split('x').Last());
     private string StreamType;
@@ -36,8 +36,8 @@ public partial class MSSMoovProcessor
     private bool IsProtection;
     private string ProtectionSystemId;
     private string ProtectionData;
-    private string ProtecitonKID;
+    private string? ProtecitonKID;
-    private string ProtecitonKID_PR;
+    private string? ProtecitonKID_PR;
     private byte[] UnityMatrix
     {
         get
@@ -60,10 +60,9 @@ public partial class MSSMoovProcessor
     private static byte TRACK_IN_MOVIE = 0x2;
     private static byte TRACK_IN_PREVIEW = 0x4;
     private static byte SELF_CONTAINED = 0x1;
-    private static List<string> SupportedFourCC = new()
+
-    {
+    private static List<string> SupportedFourCC =
-        "HVC1","HEV1","AACL","AACH","EC-3","H264","AVC1","DAVC","AVC1","TTML","DVHE","DVH1"
+        ["HVC1", "HEV1", "AACL", "AACH", "EC-3", "H264", "AVC1", "DAVC", "AVC1", "TTML", "DVHE", "DVH1"];
-    };
 
     public MSSMoovProcessor(StreamSpec streamSpec)
     {
@@ -95,7 +94,7 @@ public partial class MSSMoovProcessor
         }
     }
 
-    private static string[] HEVC_GENERAL_PROFILE_SPACE_STRINGS = new string[] { "", "A", "B", "C" };
+    private static string[] HEVC_GENERAL_PROFILE_SPACE_STRINGS = ["", "A", "B", "C"];
     private int SamplingFrequencyIndex(int samplingRate) => samplingRate switch
     {
         96000 => 0x0,
@@ -169,8 +168,8 @@ public partial class MSSMoovProcessor
             // save kid for playready
             this.ProtecitonKID_PR = HexUtil.BytesToHex(kidBytes);
             // fix byte order
-            var reverse1 = new byte[4] { kidBytes[3], kidBytes[2], kidBytes[1], kidBytes[0] };
+            var reverse1 = new[] { kidBytes[3], kidBytes[2], kidBytes[1], kidBytes[0] };
-            var reverse2 = new byte[4] { kidBytes[5], kidBytes[4], kidBytes[7], kidBytes[6] };
+            var reverse2 = new[] { kidBytes[5], kidBytes[4], kidBytes[7], kidBytes[6] };
             Array.Copy(reverse1, 0, kidBytes, 0, reverse1.Length);
             Array.Copy(reverse2, 0, kidBytes, 4, reverse1.Length);
             this.ProtecitonKID = HexUtil.BytesToHex(kidBytes);
@@ -217,13 +216,13 @@ public partial class MSSMoovProcessor
 
         var schmPayload = new List<byte>();
         schmPayload.AddRange(Encoding.ASCII.GetBytes("cenc")); // scheme_type 'cenc' => common encryption
-        schmPayload.AddRange(new byte[] { 0, 1, 0, 0 }); // scheme_version Major version 1, Minor version 0
+        schmPayload.AddRange([0, 1, 0, 0]); // scheme_version Major version 1, Minor version 0
         var schmBox = FullBox("schm", 0, 0, schmPayload.ToArray());
 
         sinfPayload.AddRange(schmBox);
 
         var tencPayload = new List<byte>();
-        tencPayload.AddRange(new byte[] { 0, 0 });
+        tencPayload.AddRange([0, 0]);
         tencPayload.Add(0x1); // default_IsProtected
         tencPayload.Add(0x8); // default_Per_Sample_IV_size
         tencPayload.AddRange(HexUtil.HexToBytes(ProtecitonKID)); // default_KID
@@ -368,7 +367,7 @@ public partial class MSSMoovProcessor
         }
         else if (StreamType == "text")
         {
-            minfPayload.AddRange(FullBox("sthd", 0, 0, new byte[0])); // Subtitle Media Header
+            minfPayload.AddRange(FullBox("sthd", 0, 0, [])); // Subtitle Media Header
         }
         else
         {
@@ -377,7 +376,7 @@ public partial class MSSMoovProcessor
 
         var drefPayload = new List<byte>();
         drefPayload.Add(0); drefPayload.Add(0); drefPayload.Add(0); drefPayload.Add(1); // entry count
-        drefPayload.AddRange(FullBox("url ", 0, SELF_CONTAINED, new byte[0])); // Data Entry URL Box
+        drefPayload.AddRange(FullBox("url ", 0, SELF_CONTAINED, [])); // Data Entry URL Box
 
         var dinfPayload = FullBox("dref", 0, 0, drefPayload.ToArray()); // Data Reference Box
         minfPayload.AddRange(Box("dinf", dinfPayload.ToArray())); // Data Information Box
@@ -466,10 +465,7 @@ public partial class MSSMoovProcessor
                     writer.Write(sinfBox);
                     return Box("enca", stream.ToArray()); // Encrypted Audio
                 }
-                else
+                return Box("mp4a", stream.ToArray());
-                {
-                    return Box("mp4a", stream.ToArray());
-                }
             }
             if (FourCC == "EC-3")
             {
@@ -479,10 +475,7 @@ public partial class MSSMoovProcessor
                     writer.Write(sinfBox);
                     return Box("enca", stream.ToArray()); // Encrypted Audio
                 }
-                else
+                return Box("ec-3", stream.ToArray());
-                {
-                    return Box("ec-3", stream.ToArray());
-                }
             }
         }
         else if (StreamType == "video")
@@ -507,11 +500,11 @@ public partial class MSSMoovProcessor
 
             var codecPrivateData = HexUtil.HexToBytes(CodecPrivateData);
 
-            if (FourCC == "H264" || FourCC == "AVC1" || FourCC == "DAVC" || FourCC == "AVC1")
+            if (FourCC is "H264" or "AVC1" or "DAVC")
             {
-                var arr = CodecPrivateData.Split(new[] { StartCode }, StringSplitOptions.RemoveEmptyEntries);
+                var arr = CodecPrivateData.Split([StartCode], StringSplitOptions.RemoveEmptyEntries);
-                var sps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] & 0x1F) == 7).First());
+                var sps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] & 0x1F) == 7));
-                var pps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] & 0x1F) == 8).First());
+                var pps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] & 0x1F) == 8));
                 // make avcC
                 var avcC = GetAvcC(sps, pps);
                 writer.Write(avcC);
@@ -521,17 +514,14 @@ public partial class MSSMoovProcessor
                     writer.Write(sinfBox);
                     return Box("encv", stream.ToArray()); // Encrypted Video
                 }
-                else
+                return Box("avc1", stream.ToArray()); // AVC Simple Entry
-                {
-                    return Box("avc1", stream.ToArray()); // AVC Simple Entry
-                }
             }
-            else if (FourCC == "HVC1" || FourCC == "HEV1")
+            if (FourCC is "HVC1" or "HEV1")
             {
-                var arr = CodecPrivateData.Split(new[] { StartCode }, StringSplitOptions.RemoveEmptyEntries);
+                var arr = CodecPrivateData.Split([StartCode], StringSplitOptions.RemoveEmptyEntries);
-                var vps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x20).First());
+                var vps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x20));
-                var sps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x21).First());
+                var sps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x21));
-                var pps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x22).First());
+                var pps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x22));
                 // make hvcC
                 var hvcC = GetHvcC(sps, pps, vps);
                 writer.Write(hvcC);
@@ -541,18 +531,15 @@ public partial class MSSMoovProcessor
                     writer.Write(sinfBox);
                     return Box("encv", stream.ToArray()); // Encrypted Video
                 }
-                else
+                return Box("hvc1", stream.ToArray()); // HEVC Simple Entry
-                {
-                    return Box("hvc1", stream.ToArray()); // HEVC Simple Entry
-                }
             }
             // 杜比视界也按照hevc处理
-            else if (FourCC == "DVHE" || FourCC == "DVH1")
+            if (FourCC is "DVHE" or "DVH1")
             {
-                var arr = CodecPrivateData.Split(new[] { StartCode }, StringSplitOptions.RemoveEmptyEntries);
+                var arr = CodecPrivateData.Split([StartCode], StringSplitOptions.RemoveEmptyEntries);
-                var vps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x20).First());
+                var vps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x20));
-                var sps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x21).First());
+                var sps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x21));
-                var pps = HexUtil.HexToBytes(arr.Where(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x22).First());
+                var pps = HexUtil.HexToBytes(arr.First(x => (HexUtil.HexToBytes(x[0..2])[0] >> 1) == 0x22));
                 // make hvcC
                 var hvcC = GetHvcC(sps, pps, vps, "dvh1");
                 writer.Write(hvcC);
@@ -562,15 +549,10 @@ public partial class MSSMoovProcessor
                     writer.Write(sinfBox);
                     return Box("encv", stream.ToArray()); // Encrypted Video
                 }
-                else
+                return Box("dvh1", stream.ToArray()); // HEVC Simple Entry
-                {
-                    return Box("dvh1", stream.ToArray()); // HEVC Simple Entry
-                }
-            }
-            else
-            {
-                throw new NotSupportedException();
             }
+
+            throw new NotSupportedException();
         }
         else if (StreamType == "text")
         {
@@ -581,10 +563,7 @@ public partial class MSSMoovProcessor
                 writer.Write("\0"); // auxilary mime types(??)
                 return Box("stpp", stream.ToArray()); // TTML Simple Entry
             }
-            else
+            throw new NotSupportedException();
-            {
-                throw new NotSupportedException();
-            }
         }
         else
         {
@@ -635,7 +614,7 @@ public partial class MSSMoovProcessor
             while (_reader.BaseStream.Position < _reader.BaseStream.Length)
             {
                 encList.Add(_reader.ReadByte());
-                if (encList.Count >= 3 && encList[encList.Count - 3] == 0x00 && encList[encList.Count - 2] == 0x00 && encList[encList.Count - 1] == 0x03)
+                if (encList is [.., 0x00, 0x00, 0x03])
                 {
                     encList.RemoveAt(encList.Count - 1);
                 }
@@ -805,7 +784,7 @@ public partial class MSSMoovProcessor
         new MP4Parser()
             .Box("moof", MP4Parser.Children)
             .Box("traf", MP4Parser.Children)
-            .FullBox("tfhd", (box) =>
+            .FullBox("tfhd", box =>
             {
                 TrackId = (int)box.Reader.ReadUInt32();
             })

src/N_m3u8DL-RE.Parser/Processor/ContentProcessor.cs

@@ -1,10 +1,5 @@
 using N_m3u8DL_RE.Common.Enum;
 using N_m3u8DL_RE.Parser.Config;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace N_m3u8DL_RE.Parser.Processor;
 

src/N_m3u8DL-RE.Parser/Processor/DASH/DefaultDASHContentProcessor.cs

@@ -1,11 +1,6 @@
 using N_m3u8DL_RE.Common.Enum;
 using N_m3u8DL_RE.Common.Log;
 using N_m3u8DL_RE.Parser.Config;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace N_m3u8DL_RE.Parser.Processor.DASH;
 
@@ -18,11 +13,7 @@ public class DefaultDASHContentProcessor : ContentProcessor
     {
         if (extractorType != ExtractorType.MPEG_DASH) return false;
 
-        if (mpdContent.Contains("<mas:") && !mpdContent.Contains("xmlns:mas"))
+        return mpdContent.Contains("<mas:") && !mpdContent.Contains("xmlns:mas");
-        {
-            return true;
-        }
-        return false;
     }
 
     public override string Process(string mpdContent, ParserConfig parserConfig)

src/N_m3u8DL-RE.Parser/Processor/DefaultUrlProcessor.cs

@@ -1,12 +1,6 @@
 using N_m3u8DL_RE.Common.Enum;
 using N_m3u8DL_RE.Common.Log;
 using N_m3u8DL_RE.Parser.Config;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 using System.Web;
 
 namespace N_m3u8DL_RE.Parser.Processor;
@@ -17,29 +11,27 @@ public class DefaultUrlProcessor : UrlProcessor
 
     public override string Process(string oriUrl, ParserConfig paserConfig)
     {
-        if (oriUrl.StartsWith("http")) 
+        if (!oriUrl.StartsWith("http")) return oriUrl;
+        
+        var uriFromConfig = new Uri(paserConfig.Url);
+        var uriFromConfigQuery = HttpUtility.ParseQueryString(uriFromConfig.Query);
+
+        var oldUri = new Uri(oriUrl);
+        var newQuery = HttpUtility.ParseQueryString(oldUri.Query);
+        foreach (var item in uriFromConfigQuery.AllKeys)
         {
-            var uriFromConfig = new Uri(paserConfig.Url);
+            if (newQuery.AllKeys.Contains(item))
-            var uriFromConfigQuery = HttpUtility.ParseQueryString(uriFromConfig.Query);
+                newQuery.Set(item, uriFromConfigQuery.Get(item));
-
+            else
-            var oldUri = new Uri(oriUrl);
+                newQuery.Add(item, uriFromConfigQuery.Get(item));
-            var newQuery = HttpUtility.ParseQueryString(oldUri.Query);
-            foreach (var item in uriFromConfigQuery.AllKeys)
-            {
-                if (newQuery.AllKeys.Contains(item))
-                    newQuery.Set(item, uriFromConfigQuery.Get(item));
-                else
-                    newQuery.Add(item, uriFromConfigQuery.Get(item));
-            }
-
-            if (!string.IsNullOrEmpty(newQuery.ToString()))
-            {
-                Logger.Debug("Before: " + oriUrl);
-                oriUrl = (oldUri.GetLeftPart(UriPartial.Path) + "?" + newQuery.ToString()).TrimEnd('?');
-                Logger.Debug("After: " + oriUrl);
-            }
         }
 
+        if (string.IsNullOrEmpty(newQuery.ToString())) return oriUrl;
+        
+        Logger.Debug("Before: " + oriUrl);
+        oriUrl = (oldUri.GetLeftPart(UriPartial.Path) + "?" + newQuery).TrimEnd('?');
+        Logger.Debug("After: " + oriUrl);
+
         return oriUrl;
     }
 }

src/N_m3u8DL-RE.Parser/Processor/HLS/DefaultHLSContentProcessor.cs

@@ -1,12 +1,7 @@
 using N_m3u8DL_RE.Common.Enum;
 using N_m3u8DL_RE.Parser.Config;
 using N_m3u8DL_RE.Parser.Constants;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 
 namespace N_m3u8DL_RE.Parser.Processor.HLS;
 
@@ -16,13 +11,13 @@ public partial class DefaultHLSContentProcessor : ContentProcessor
     private static partial Regex YkDVRegex();
     [GeneratedRegex("#EXT-X-MAP:URI=\\\".*?BUMPER/[\\s\\S]+?#EXT-X-DISCONTINUITY")]
     private static partial Regex DNSPRegex();
-    [GeneratedRegex("#EXTINF:.*?,\\s+.*BUMPER.*\\s+?#EXT-X-DISCONTINUITY")]
+    [GeneratedRegex(@"#EXTINF:.*?,\s+.*BUMPER.*\s+?#EXT-X-DISCONTINUITY")]
     private static partial Regex DNSPSubRegex();
     [GeneratedRegex("(#EXTINF.*)(\\s+)(#EXT-X-KEY.*)")]
     private static partial Regex OrderFixRegex();
-    [GeneratedRegex("#EXT-X-MAP.*\\.apple\\.com/")]
+    [GeneratedRegex(@"#EXT-X-MAP.*\.apple\.com/")]
     private static partial Regex ATVRegex();
-    [GeneratedRegex("(#EXT-X-KEY:[\\s\\S]*?)(#EXT-X-DISCONTINUITY|#EXT-X-ENDLIST)")]
+    [GeneratedRegex(@"(#EXT-X-KEY:[\s\S]*?)(#EXT-X-DISCONTINUITY|#EXT-X-ENDLIST)")]
     private static partial Regex ATVRegex2();
 
     public override bool CanProcess(ExtractorType extractorType, string rawText, ParserConfig parserConfig) => extractorType == ExtractorType.HLS;
@@ -30,7 +25,7 @@ public partial class DefaultHLSContentProcessor : ContentProcessor
     public override string Process(string m3u8Content, ParserConfig parserConfig)
     {
         // 处理content以\r作为换行符的情况
-        if (m3u8Content.Contains("\r") && !m3u8Content.Contains("\n"))
+        if (m3u8Content.Contains('\r') && !m3u8Content.Contains('\n'))
         {
             m3u8Content = m3u8Content.Replace("\r", Environment.NewLine);
         }
@@ -51,7 +46,7 @@ public partial class DefaultHLSContentProcessor : ContentProcessor
         // 针对YK #EXT-X-VERSION:7杜比视界片源修正
         if (m3u8Content.Contains("#EXT-X-DISCONTINUITY") && m3u8Content.Contains("#EXT-X-MAP") && m3u8Content.Contains("ott.cibntv.net") && m3u8Content.Contains("ccode="))
         {
-            Regex ykmap = YkDVRegex();
+            var ykmap = YkDVRegex();
             foreach (Match m in ykmap.Matches(m3u8Content))
             {
                 m3u8Content = m3u8Content.Replace(m.Value, $"#EXTINF:0.000000,\n#EXT-X-BYTERANGE:{m.Groups[2].Value}\n{m.Groups[1].Value}");

src/N_m3u8DL-RE.Parser/Processor/HLS/DefaultHLSKeyProcessor.cs

@@ -83,12 +83,11 @@ public class DefaultHLSKeyProcessor : KeyProcessor
             encryptInfo.Method = EncryptMethod.UNKNOWN;
         }
 
+        if (parserConfig.CustomMethod == null) return encryptInfo;
+        
         // 处理自定义加密方式
-        if (parserConfig.CustomMethod != null)
+        encryptInfo.Method = parserConfig.CustomMethod.Value;
-        {
+        Logger.Warn("METHOD changed from {} to {}", method, encryptInfo.Method);
-            encryptInfo.Method = parserConfig.CustomMethod.Value;
-            Logger.Warn("METHOD changed from {} to {}", method, encryptInfo.Method);
-        }
 
         return encryptInfo;
     }

src/N_m3u8DL-RE.Parser/Processor/KeyProcessor.cs

@@ -1,11 +1,6 @@
 using N_m3u8DL_RE.Common.Entity;
 using N_m3u8DL_RE.Common.Enum;
 using N_m3u8DL_RE.Parser.Config;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace N_m3u8DL_RE.Parser.Processor;
 

src/N_m3u8DL-RE.Parser/StreamExtractor.cs

@@ -1,4 +1,5 @@
-using N_m3u8DL_RE.Parser.Config;
+using System.Diagnostics.CodeAnalysis;
+using N_m3u8DL_RE.Parser.Config;
 using N_m3u8DL_RE.Common.Entity;
 using N_m3u8DL_RE.Common.Log;
 using N_m3u8DL_RE.Common.Resource;
@@ -19,11 +20,6 @@ public class StreamExtractor
 
     public Dictionary<string, string> RawFiles { get; set; } = new(); // 存储（文件名,文件内容）
 
-    public StreamExtractor()
-    {
-
-    }
-
     public StreamExtractor(ParserConfig parserConfig)
     {
         this.parserConfig = parserConfig;
@@ -54,7 +50,8 @@ public class StreamExtractor
         LoadSourceFromText(this.rawText);
     }
 
-    public void LoadSourceFromText(string rawText)
+    [MemberNotNull(nameof(this.rawText), nameof(this.extractor))]
+    private void LoadSourceFromText(string rawText)
     {
         var rawType = "txt";
         rawText = rawText.Trim();

src/N_m3u8DL-RE.Parser/Util/ParserUtil.cs

@@ -3,9 +3,9 @@ using System.Text.RegularExpressions;
 
 namespace N_m3u8DL_RE.Parser.Util;
 
-public partial class ParserUtil
+public static partial class ParserUtil
 {
-    [GeneratedRegex("\\$Number%([^$]+)d\\$")]
+    [GeneratedRegex(@"\$Number%([^$]+)d\$")]
     private static partial Regex VarsNumberRegex();
 
     /// <summary>
@@ -33,8 +33,7 @@ public partial class ParserUtil
         {
             var startIndex = index + (key + "=").Length;
             var endIndex = startIndex + line[startIndex..].IndexOf(',');
-            if (endIndex >= startIndex) result = line[startIndex..endIndex];
+            result = endIndex >= startIndex ? line[startIndex..endIndex] : line[startIndex..];
-            else result = line[startIndex..];
         }
 
         return result;
@@ -49,18 +48,13 @@ public partial class ParserUtil
     public static (long, long?) GetRange(string input)
     {
         var t = input.Split('@');
-        if (t.Length > 0)
+        return t.Length switch
         {
-            if (t.Length == 1)
+            <= 0 => (0, null),
-            {
+            1 => (Convert.ToInt64(t[0]), null),
-                return (Convert.ToInt64(t[0]), null);
+            2 => (Convert.ToInt64(t[0]), Convert.ToInt64(t[1])),
-            }
+            _ => (0, null)
-            if (t.Length == 2)
+        };
-            {
-                return (Convert.ToInt64(t[0]), Convert.ToInt64(t[1]));
-            }
-        }
-        return (0, null);
     }
 
     /// <summary>
@@ -111,8 +105,8 @@ public partial class ParserUtil
         if (string.IsNullOrEmpty(baseurl))
             return url;
 
-        Uri uri1 = new Uri(baseurl);  // 这里直接传完整的URL即可
+        var uri1 = new Uri(baseurl);  // 这里直接传完整的URL即可
-        Uri uri2 = new Uri(uri1, url);
+        var uri2 = new Uri(uri1, url);
         url = uri2.ToString();
 
         return url;

src/N_m3u8DL-RE/Column/DownloadSpeedColumn.cs

@@ -27,7 +27,7 @@ internal sealed class DownloadSpeedColumn : ProgressColumn
         var now = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
         var flag = task.IsFinished || !task.IsStarted;
         // 单文件下载汇报进度
-        if (!flag && speedContainer.SingleSegment && speedContainer.ResponseLength != null)
+        if (!flag && speedContainer is { SingleSegment: true, ResponseLength: not null })
         {
             task.MaxValue = (double)speedContainer.ResponseLength;
             task.Value = speedContainer.RDownloaded;

src/N_m3u8DL-RE/Column/RecordingDurationColumn.cs

@@ -25,9 +25,6 @@ internal class RecordingDurationColumn : ProgressColumn
     {
         if (_refreshedDurDic == null)
             return new Text($"{GlobalUtil.FormatTime(_recodingDurDic[task.Id])}", MyStyle).LeftJustified();
-        else
+        return new Text($"{GlobalUtil.FormatTime(_recodingDurDic[task.Id])}/{GlobalUtil.FormatTime(_refreshedDurDic[task.Id])}", GreyStyle);
-        {                
-            return new Text($"{GlobalUtil.FormatTime(_recodingDurDic[task.Id])}/{GlobalUtil.FormatTime(_refreshedDurDic[task.Id])}", GreyStyle);
-        }
     }
 }

src/N_m3u8DL-RE/CommandLine/CommandInvoker.cs

@@ -15,14 +15,16 @@ using System.Text.RegularExpressions;
 
 namespace N_m3u8DL_RE.CommandLine;
 
-internal partial class CommandInvoker
+internal static partial class CommandInvoker
 {
-    public const string VERSION_INFO = "N_m3u8DL-RE (Beta version) 20241130";
+    public const string VERSION_INFO = "N_m3u8DL-RE (Beta version) 20241201";
 
     [GeneratedRegex("((best|worst)\\d*|all)")]
     private static partial Regex ForStrRegex();
-    [GeneratedRegex("(\\d*)-(\\d*)")]
+    [GeneratedRegex(@"(\d*)-(\d*)")]
     private static partial Regex RangeRegex();
+    [GeneratedRegex(@"([\d\\.]+)(M|K)")]
+    private static partial Regex SpeedStrRegex();
 
     private static readonly Argument<string> Input = new(name: "input", description: ResString.cmd_Input);
     private static readonly Option<string?> TmpDir = new(["--tmp-dir"], description: ResString.cmd_tmpDir);
@@ -110,23 +112,22 @@ internal partial class CommandInvoker
     private static readonly Option<StreamFilter?> DropSubtitleFilter = new(["-ds", "--drop-subtitle"], description: ResString.cmd_dropSubtitle, parseArgument: ParseStreamFilter) { ArgumentHelpName = "OPTIONS" };
 
     /// <summary>
-    /// 解析录制直播时长限制
+    /// 解析下载速度限制
     /// </summary>
     /// <param name="result"></param>
     /// <returns></returns>
     private static long? ParseSpeedLimit(ArgumentResult result)
     {
-        var input = result.Tokens.First().Value.ToUpper();
+        var input = result.Tokens[0].Value.ToUpper();
         try
         {
-            var reg = new Regex("([\\d\\\\.]+)(M|K)");
+            var reg = SpeedStrRegex();
-            if (!reg.IsMatch(input)) throw new ArgumentException();
+            if (!reg.IsMatch(input)) throw new ArgumentException($"Invalid Speed Limit: {input}");
 
             var number = double.Parse(reg.Match(input).Groups[1].Value);
             if (reg.Match(input).Groups[2].Value == "M")
                 return (long)(number * 1024 * 1024);
-            else
+            return (long)(number * 1024);
-                return (long)(number * 1024);
         }
         catch (Exception)
         {
@@ -143,7 +144,7 @@ internal partial class CommandInvoker
     /// <exception cref="ArgumentException"></exception>
     private static CustomRange? ParseCustomRange(ArgumentResult result)
     {
-        var input = result.Tokens.First().Value;
+        var input = result.Tokens[0].Value;
         // 支持的种类 0-100; 01:00:00-02:30:00; -300; 300-; 05:00-; -03:00;
         try
         {
@@ -154,7 +155,7 @@ internal partial class CommandInvoker
             if (arr.Length != 2)
                 throw new ArgumentException("Bad format!");
 
-            if (input.Contains(":"))
+            if (input.Contains(':'))
             {
                 return new CustomRange()
                 {
@@ -163,7 +164,8 @@ internal partial class CommandInvoker
                     EndSec = arr[1] == "" ? double.MaxValue : OtherUtil.ParseDur(arr[1]).TotalSeconds,
                 };
             }
-            else if (RangeRegex().IsMatch(input))
+
+            if (RangeRegex().IsMatch(input))
             {
                 var left = RangeRegex().Match(input).Groups[1].Value;
                 var right = RangeRegex().Match(input).Groups[2].Value;
@@ -192,7 +194,7 @@ internal partial class CommandInvoker
     /// <exception cref="ArgumentException"></exception>
     private static WebProxy? ParseProxy(ArgumentResult result)
     {
-        var input = result.Tokens.First().Value;
+        var input = result.Tokens[0].Value;
         try
         {
             if (string.IsNullOrEmpty(input))
@@ -221,17 +223,16 @@ internal partial class CommandInvoker
     /// <returns></returns>
     private static byte[]? ParseHLSCustomKey(ArgumentResult result)
     {
-        var input = result.Tokens.First().Value;
+        var input = result.Tokens[0].Value;
         try
         {
             if (string.IsNullOrEmpty(input))
                 return null;
             if (File.Exists(input))
                 return File.ReadAllBytes(input);
-            else if (HexUtil.TryParseHexString(input, out byte[]? bytes))
+            if (HexUtil.TryParseHexString(input, out byte[]? bytes))
                 return bytes;
-            else
+            return Convert.FromBase64String(input);
-                return Convert.FromBase64String(input);
         }
         catch (Exception)
         {
@@ -247,7 +248,7 @@ internal partial class CommandInvoker
     /// <returns></returns>
     private static TimeSpan? ParseLiveLimit(ArgumentResult result)
     {
-        var input = result.Tokens.First().Value;
+        var input = result.Tokens[0].Value;
         try
         {
             return OtherUtil.ParseDur(input);
@@ -266,7 +267,7 @@ internal partial class CommandInvoker
     /// <returns></returns>
     private static DateTime? ParseStartTime(ArgumentResult result)
     {
-        var input = result.Tokens.First().Value;
+        var input = result.Tokens[0].Value;
         try
         {
             CultureInfo provider = CultureInfo.InvariantCulture;
@@ -281,7 +282,7 @@ internal partial class CommandInvoker
 
     private static string? ParseSaveName(ArgumentResult result)
     {
-        var input = result.Tokens.First().Value;
+        var input = result.Tokens[0].Value;
         var newName = OtherUtil.GetValidFileName(input);
         if (string.IsNullOrEmpty(newName))
         {
@@ -299,7 +300,7 @@ internal partial class CommandInvoker
     private static StreamFilter? ParseStreamFilter(ArgumentResult result)
     {
         var streamFilter = new StreamFilter();
-        var input = result.Tokens.First().Value;
+        var input = result.Tokens[0].Value;
         var p = new ComplexParamParser(input);
 
 
@@ -437,7 +438,7 @@ internal partial class CommandInvoker
     /// <returns></returns>
     private static MuxOptions? ParseMuxAfterDone(ArgumentResult result)
     {
-        var v = result.Tokens.First().Value;
+        var v = result.Tokens[0].Value;
         var p = new ComplexParamParser(v);
         // 混流格式
         var format = p.GetValue("format") ?? v.Split(':')[0]; // 若未获取到，直接:前的字符串作为format解析
@@ -577,14 +578,12 @@ internal partial class CommandInvoker
 
             // 混流设置
             var muxAfterDoneValue = bindingContext.ParseResult.GetValueForOption(MuxAfterDone);
-            if (muxAfterDoneValue != null)
+            if (muxAfterDoneValue == null) return option;
-            {
+            
-                option.MuxAfterDone = true;
+            option.MuxAfterDone = true;
-                option.MuxOptions = muxAfterDoneValue;
+            option.MuxOptions = muxAfterDoneValue;
-                if (muxAfterDoneValue.UseMkvmerge) option.MkvmergeBinaryPath = muxAfterDoneValue.BinPath;
+            if (muxAfterDoneValue.UseMkvmerge) option.MkvmergeBinaryPath = muxAfterDoneValue.BinPath;
-                else option.FFmpegBinaryPath ??= muxAfterDoneValue.BinPath;
+            else option.FFmpegBinaryPath ??= muxAfterDoneValue.BinPath;
-            }
-
 
             return option;
         }
@@ -626,7 +625,7 @@ internal partial class CommandInvoker
         };
 
         rootCommand.TreatUnmatchedTokensAsErrors = true;
-        rootCommand.SetHandler(async (myOption) => await action(myOption), new MyOptionBinder());
+        rootCommand.SetHandler(async myOption => await action(myOption), new MyOptionBinder());
 
         var parser = new CommandLineBuilder(rootCommand)
             .UseDefaults()

src/N_m3u8DL-RE/CommandLine/ComplexParamParser.cs

@@ -4,7 +4,7 @@ namespace N_m3u8DL_RE.CommandLine;
 
 internal class ComplexParamParser
 {
-    private string _arg;
+    private readonly string _arg;
     public ComplexParamParser(string arg)
     {
         _arg = arg;
@@ -16,7 +16,7 @@ internal class ComplexParamParser
 
         try
         {
-            var index = _arg.IndexOf(key + "=");
+            var index = _arg.IndexOf(key + "=", StringComparison.Ordinal);
             if (index == -1) return (_arg.Contains(key) && _arg.EndsWith(key)) ? "true" : null;
 
             var chars = _arg[(index + key.Length + 1)..].ToCharArray();

src/N_m3u8DL-RE/Crypto/AESUtil.cs

@@ -2,7 +2,7 @@
 
 namespace N_m3u8DL_RE.Crypto;
 
-internal class AESUtil
+internal static class AESUtil
 {
     /// <summary>
     /// AES-128解密，解密后原地替换文件

src/N_m3u8DL-RE/Crypto/ChaCha20Util.cs

@@ -2,7 +2,7 @@
 
 namespace N_m3u8DL_RE.Crypto;
 
-internal class ChaCha20Util
+internal static class ChaCha20Util
 {
     public static byte[] DecryptPer1024Bytes(byte[] encryptedBuff, byte[] keyBytes, byte[] nonceBytes)
     {

src/N_m3u8DL-RE/DownloadManager/HTTPLiveRecordManager.cs

@@ -20,7 +20,7 @@ internal class HTTPLiveRecordManager
     DownloaderConfig DownloaderConfig;
     StreamExtractor StreamExtractor;
     List<StreamSpec> SelectedSteams;
-    List<OutputFile> OutputFiles = new();
+    List<OutputFile> OutputFiles = [];
     DateTime NowDateTime;
     DateTime? PublishDateTime;
     bool STOP_FLAG = false;
@@ -107,7 +107,7 @@ internal class HTTPLiveRecordManager
             await Task.Delay(200);
             if (InfoBuffer.Count < 188 * 5000) continue;
 
-            UInt16 ConvertToUint16(IEnumerable<byte> bytes)
+            ushort ConvertToUint16(IEnumerable<byte> bytes)
             {
                 if (BitConverter.IsLittleEndian)
                     bytes = bytes.Reverse();
@@ -217,7 +217,7 @@ internal class HTTPLiveRecordManager
                 return (item, task);
             }).ToDictionary(item => item.item, item => item.task);
 
-            DownloaderConfig.MyOptions.LiveRecordLimit = DownloaderConfig.MyOptions.LiveRecordLimit ?? TimeSpan.MaxValue;
+            DownloaderConfig.MyOptions.LiveRecordLimit ??= TimeSpan.MaxValue;
             var limit = DownloaderConfig.MyOptions.LiveRecordLimit;
             if (limit != TimeSpan.MaxValue)
                 Logger.WarnMarkUp($"[darkorange3_1]{ResString.liveLimit}{GlobalUtil.FormatTime((int)limit.Value.TotalSeconds)}[/]");

src/N_m3u8DL-RE/DownloadManager/SimpleDownloadManager.cs

@@ -23,7 +23,7 @@ internal class SimpleDownloadManager
     DownloaderConfig DownloaderConfig;
     StreamExtractor StreamExtractor;
     List<StreamSpec> SelectedSteams;
-    List<OutputFile> OutputFiles = new();
+    List<OutputFile> OutputFiles = [];
 
     public SimpleDownloadManager(DownloaderConfig downloaderConfig, List<StreamSpec> selectedSteams, StreamExtractor streamExtractor) 
     { 
@@ -48,13 +48,13 @@ internal class SimpleDownloadManager
 
     private void ChangeSpecInfo(StreamSpec streamSpec, List<Mediainfo> mediainfos, ref bool useAACFilter)
     {
-        if (!DownloaderConfig.MyOptions.BinaryMerge && mediainfos.Any(m => m.DolbyVison == true))
+        if (!DownloaderConfig.MyOptions.BinaryMerge && mediainfos.Any(m => m.DolbyVison))
         {
             DownloaderConfig.MyOptions.BinaryMerge = true;
             Logger.WarnMarkUp($"[darkorange3_1]{ResString.autoBinaryMerge2}[/]");
         }
 
-        if (DownloaderConfig.MyOptions.MuxAfterDone && mediainfos.Any(m => m.DolbyVison == true))
+        if (DownloaderConfig.MyOptions.MuxAfterDone && mediainfos.Any(m => m.DolbyVison))
         {
             DownloaderConfig.MyOptions.MuxAfterDone = false;
             Logger.WarnMarkUp($"[darkorange3_1]{ResString.autoBinaryMerge5}[/]");
@@ -72,7 +72,7 @@ internal class SimpleDownloadManager
         else if (mediainfos.All(m => m.Type == "Subtitle"))
         {
             streamSpec.MediaType = MediaType.SUBTITLES;
-            if (streamSpec.Extension == null || streamSpec.Extension == "ts")
+            if (streamSpec.Extension is null or "ts")
                 streamSpec.Extension = "vtt";
         }
     }
@@ -81,7 +81,7 @@ internal class SimpleDownloadManager
     {
         speedContainer.ResetVars();
         bool useAACFilter = false; // ffmpeg合并flag
-        List<Mediainfo> mediaInfos = new();
+        List<Mediainfo> mediaInfos = [];
         ConcurrentDictionary<MediaSegment, DownloadResult?> FileDic = new();
 
         var segments = streamSpec.Playlist?.MediaParts.SelectMany(m => m.MediaSegments);
@@ -158,7 +158,7 @@ internal class SimpleDownloadManager
             var path = Path.Combine(tmpDir, "_init.mp4.tmp");
             var result = await Downloader.DownloadSegmentAsync(streamSpec.Playlist.MediaInit, path, speedContainer, headers);
             FileDic[streamSpec.Playlist.MediaInit] = result;
-            if (result == null || !result.Success)
+            if (result is not { Success: true })
             {
                 throw new Exception("Download init file failed!");
             }
@@ -166,7 +166,7 @@ internal class SimpleDownloadManager
             task.Increment(1);
 
             // 读取mp4信息
-            if (result != null && result.Success) 
+            if (result is { Success: true }) 
             {
                 mp4Info = MP4DecryptUtil.GetMP4Info(result.ActualFilePath);
                 currentKID = mp4Info.KID;
@@ -212,12 +212,12 @@ internal class SimpleDownloadManager
             var path = Path.Combine(tmpDir, index.ToString(pad) + $".{streamSpec.Extension ?? "clip"}.tmp");
             var result = await Downloader.DownloadSegmentAsync(seg, path, speedContainer, headers);
             FileDic[seg] = result;
-            if (result == null || !result.Success)
+            if (result is not { Success: true })
             {
                 throw new Exception("Download first segment failed!");
             }
             task.Increment(1);
-            if (result != null && result.Success)
+            if (result is { Success: true })
             {
                 // 修复MSS init
                 if (StreamExtractor.ExtractorType == ExtractorType.MSS)
@@ -284,10 +284,10 @@ internal class SimpleDownloadManager
             var path = Path.Combine(tmpDir, index.ToString(pad) + $".{streamSpec.Extension ?? "clip"}.tmp");
             var result = await Downloader.DownloadSegmentAsync(seg, path, speedContainer, headers);
             FileDic[seg] = result;
-            if (result != null && result.Success)
+            if (result is { Success: true })
                 task.Increment(1);
             // 实时解密
-            if (seg.IsEncrypted && DownloaderConfig.MyOptions.MP4RealTimeDecryption && result != null && result.Success && !string.IsNullOrEmpty(currentKID)) 
+            if (seg.IsEncrypted && DownloaderConfig.MyOptions.MP4RealTimeDecryption && result is { Success: true } && !string.IsNullOrEmpty(currentKID)) 
             {
                 var enc = result.ActualFilePath;
                 var dec = Path.Combine(Path.GetDirectoryName(enc)!, Path.GetFileNameWithoutExtension(enc) + "_dec" + Path.GetExtension(enc));
@@ -304,13 +304,12 @@ internal class SimpleDownloadManager
         // 修改输出后缀
         var outputExt = "." + streamSpec.Extension;
         if (streamSpec.Extension == null) outputExt = ".ts";
-        else if (streamSpec.MediaType == MediaType.AUDIO && (streamSpec.Extension == "m4s" || streamSpec.Extension == "mp4")) outputExt = ".m4a";
+        else if (streamSpec is { MediaType: MediaType.AUDIO, Extension: "m4s" or "mp4" }) outputExt = ".m4a";
-        else if (streamSpec.MediaType != MediaType.SUBTITLES && (streamSpec.Extension == "m4s" || streamSpec.Extension == "mp4")) outputExt = ".mp4";
+        else if (streamSpec.MediaType != MediaType.SUBTITLES && streamSpec.Extension is "m4s" or "mp4") outputExt = ".mp4";
 
         if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == MediaType.SUBTITLES)
         {
-            if (DownloaderConfig.MyOptions.SubtitleFormat == Enum.SubtitleFormat.SRT) outputExt = ".srt";
+            outputExt = DownloaderConfig.MyOptions.SubtitleFormat == Enum.SubtitleFormat.SRT ? ".srt" : ".vtt";
-            else outputExt = ".vtt";
         }
         var output = Path.Combine(saveDir, saveName + outputExt);
 
@@ -320,7 +319,7 @@ internal class SimpleDownloadManager
             Logger.WarnMarkUp($"{Path.GetFileName(output)} => {Path.GetFileName(output = Path.ChangeExtension(output, $"copy" + Path.GetExtension(output)))}");
         }
 
-        if (!string.IsNullOrEmpty(currentKID) && DownloaderConfig.MyOptions.MP4RealTimeDecryption && DownloaderConfig.MyOptions.Keys != null && DownloaderConfig.MyOptions.Keys.Length > 0 && mp4InitFile != "")
+        if (!string.IsNullOrEmpty(currentKID) && DownloaderConfig.MyOptions is { MP4RealTimeDecryption: true, Keys.Length: > 0 } && mp4InitFile != "")
         {
             File.Delete(mp4InitFile);
             // shaka/ffmpeg实时解密不需要init文件用于合并
@@ -333,7 +332,7 @@ internal class SimpleDownloadManager
         // 校验分片数量
         if (DownloaderConfig.MyOptions.CheckSegmentsCount && FileDic.Values.Any(s => s == null))
         {
-            Logger.ErrorMarkUp(ResString.segmentCountCheckNotPass, totalCount, FileDic.Values.Where(s => s != null).Count());
+            Logger.ErrorMarkUp(ResString.segmentCountCheckNotPass, totalCount, FileDic.Values.Count(s => s != null));
             return false;
         }
 
@@ -351,8 +350,7 @@ internal class SimpleDownloadManager
         }
 
         // 自动修复VTT raw字幕
-        if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES 
+        if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec is { MediaType: Common.Enum.MediaType.SUBTITLES, Extension: not null } && streamSpec.Extension.Contains("vtt")) 
-                                                       && streamSpec.Extension != null && streamSpec.Extension.Contains("vtt")) 
         {
             Logger.WarnMarkUp(ResString.fixingVTT);
             // 排序字幕并修正时间戳
@@ -398,7 +396,7 @@ internal class SimpleDownloadManager
         if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
                                                        && streamSpec.Codecs != "stpp" && streamSpec.Extension != null && streamSpec.Extension.Contains("m4s"))
         {
-            var initFile = FileDic.Values.Where(v => Path.GetFileName(v!.ActualFilePath).StartsWith("_init")).FirstOrDefault();
+            var initFile = FileDic.Values.FirstOrDefault(v => Path.GetFileName(v!.ActualFilePath).StartsWith("_init"));
             var iniFileBytes = File.ReadAllBytes(initFile!.ActualFilePath);
             var (sawVtt, timescale) = MP4VttUtil.CheckInit(iniFileBytes);
             if (sawVtt)
@@ -432,8 +430,7 @@ internal class SimpleDownloadManager
         }
 
         // 自动修复TTML raw字幕
-        if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
+        if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec is { MediaType: Common.Enum.MediaType.SUBTITLES, Extension: not null } && streamSpec.Extension.Contains("ttml"))
-                                                       && streamSpec.Extension != null && streamSpec.Extension.Contains("ttml"))
         {
             Logger.WarnMarkUp(ResString.fixingTTML);
             var first = true;
@@ -479,9 +476,8 @@ internal class SimpleDownloadManager
         }
 
         // 自动修复TTML mp4字幕
-        if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
+        if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec is { MediaType: Common.Enum.MediaType.SUBTITLES, Extension: not null } && streamSpec.Extension.Contains("m4s")
-                                                       && streamSpec.Extension != null && streamSpec.Extension.Contains("m4s")
+            && streamSpec.Codecs != null && streamSpec.Codecs.Contains("stpp")) 
-                                                       && streamSpec.Codecs != null && streamSpec.Codecs.Contains("stpp")) 
         {
             Logger.WarnMarkUp(ResString.fixingTTMLmp4);
             // sawTtml暂时不判断
@@ -575,7 +571,7 @@ internal class SimpleDownloadManager
         }
 
         // 删除临时文件夹
-        if (!DownloaderConfig.MyOptions.SkipMerge && DownloaderConfig.MyOptions.DelAfterDone && mergeSuccess)
+        if (DownloaderConfig.MyOptions is { SkipMerge: false, DelAfterDone: true } && mergeSuccess)
         {
             var files = FileDic.Values.Select(v => v!.ActualFilePath);
             foreach (var file in files)
@@ -598,7 +594,7 @@ internal class SimpleDownloadManager
         }
 
         // 调用mp4decrypt解密
-        if (mergeSuccess && File.Exists(output) && !string.IsNullOrEmpty(currentKID) && !DownloaderConfig.MyOptions.MP4RealTimeDecryption && DownloaderConfig.MyOptions.Keys != null && DownloaderConfig.MyOptions.Keys.Length > 0)
+        if (mergeSuccess && File.Exists(output) && !string.IsNullOrEmpty(currentKID) && DownloaderConfig.MyOptions is { MP4RealTimeDecryption: false, Keys.Length: > 0 })
         {
             var enc = output;
             var dec = Path.Combine(Path.GetDirectoryName(enc)!, Path.GetFileNameWithoutExtension(enc) + "_dec" + Path.GetExtension(enc));
@@ -700,7 +696,7 @@ internal class SimpleDownloadManager
         var success = Results.Values.All(v => v == true);
 
         // 删除临时文件夹
-        if (!DownloaderConfig.MyOptions.SkipMerge && DownloaderConfig.MyOptions.DelAfterDone && success)
+        if (DownloaderConfig.MyOptions is { SkipMerge: false, DelAfterDone: true } && success)
         {
             foreach (var item in StreamExtractor.RawFiles)
             {

src/N_m3u8DL-RE/DownloadManager/SimpleLiveRecordManager2.cs

@@ -27,7 +27,7 @@ internal class SimpleLiveRecordManager2
     StreamExtractor StreamExtractor;
     List<StreamSpec> SelectedSteams;
     ConcurrentDictionary<int, string> PipeSteamNamesDic = new();
-    List<OutputFile> OutputFiles = new();
+    List<OutputFile> OutputFiles = [];
     DateTime? PublishDateTime;
     bool STOP_FLAG = false;
     int WAIT_SEC = 0; // 刷新间隔
@@ -41,7 +41,7 @@ internal class SimpleLiveRecordManager2
     ConcurrentDictionary<int, long> DateTimeDic = new(); // 上次下载的dateTime
     CancellationTokenSource CancellationTokenSource = new(); // 取消Wait
 
-    private readonly object lockObj = new object();
+    private readonly Lock lockObj = new();
     TimeSpan? audioStart = null;
 
     public SimpleLiveRecordManager2(DownloaderConfig downloaderConfig, List<StreamSpec> selectedSteams, StreamExtractor streamExtractor)
@@ -60,9 +60,9 @@ internal class SimpleLiveRecordManager2
         if (_key != null)
         {
             if (DownloaderConfig.MyOptions.Keys == null)
-                DownloaderConfig.MyOptions.Keys = new string[] { _key };
+                DownloaderConfig.MyOptions.Keys = [_key];
             else
-                DownloaderConfig.MyOptions.Keys = DownloaderConfig.MyOptions.Keys.Concat(new string[] { _key }).ToArray();
+                DownloaderConfig.MyOptions.Keys = [..DownloaderConfig.MyOptions.Keys, _key];
         }
     }
 
@@ -111,13 +111,13 @@ internal class SimpleLiveRecordManager2
 
     private void ChangeSpecInfo(StreamSpec streamSpec, List<Mediainfo> mediainfos, ref bool useAACFilter)
     {
-        if (!DownloaderConfig.MyOptions.BinaryMerge && mediainfos.Any(m => m.DolbyVison == true))
+        if (!DownloaderConfig.MyOptions.BinaryMerge && mediainfos.Any(m => m.DolbyVison))
         {
             DownloaderConfig.MyOptions.BinaryMerge = true;
             Logger.WarnMarkUp($"[darkorange3_1]{ResString.autoBinaryMerge2}[/]");
         }
 
-        if (DownloaderConfig.MyOptions.MuxAfterDone && mediainfos.Any(m => m.DolbyVison == true))
+        if (DownloaderConfig.MyOptions.MuxAfterDone && mediainfos.Any(m => m.DolbyVison))
         {
             DownloaderConfig.MyOptions.MuxAfterDone = false;
             Logger.WarnMarkUp($"[darkorange3_1]{ResString.autoBinaryMerge5}[/]");
@@ -136,7 +136,7 @@ internal class SimpleLiveRecordManager2
         {
             streamSpec.MediaType = MediaType.SUBTITLES;
 
-            if (streamSpec.Extension == null || streamSpec.Extension == "ts")
+            if (streamSpec.Extension is null or "ts")
                 streamSpec.Extension = "vtt";
         }
     }
@@ -151,7 +151,7 @@ internal class SimpleLiveRecordManager2
         bool useAACFilter = false; // ffmpeg合并flag
         bool initDownloaded = false; // 是否下载过init文件
         ConcurrentDictionary<MediaSegment, DownloadResult?> FileDic = new();
-        List<Mediainfo> mediaInfos = new();
+        List<Mediainfo> mediaInfos = [];
         Stream? fileOutputStream = null;
         WebVttSub currentVtt = new(); // 字幕流始终维护一个实例
         bool firstSub = true;
@@ -197,7 +197,7 @@ internal class SimpleLiveRecordManager2
                 var path = Path.Combine(tmpDir, "_init.mp4.tmp");
                 var result = await Downloader.DownloadSegmentAsync(streamSpec.Playlist.MediaInit, path, speedContainer, headers);
                 FileDic[streamSpec.Playlist.MediaInit] = result;
-                if (result == null || !result.Success)
+                if (result is not { Success: true })
                 {
                     throw new Exception("Download init file failed!");
                 }
@@ -205,7 +205,7 @@ internal class SimpleLiveRecordManager2
                 task.Increment(1);
 
                 // 读取mp4信息
-                if (result != null && result.Success)
+                if (result is { Success: true })
                 {
                     currentKID = MP4DecryptUtil.GetMP4Info(result.ActualFilePath).KID;
                     // 从文件读取KEY
@@ -257,12 +257,12 @@ internal class SimpleLiveRecordManager2
                 var path = Path.Combine(tmpDir, filename + $".{streamSpec.Extension ?? "clip"}.tmp");
                 var result = await Downloader.DownloadSegmentAsync(seg, path, speedContainer, headers);
                 FileDic[seg] = result;
-                if (result == null || !result.Success)
+                if (result is not { Success: true })
                 {
                     throw new Exception("Download first segment failed!");
                 }
                 task.Increment(1);
-                if (result != null && result.Success)
+                if (result is { Success: true })
                 {
                     // 修复MSS init
                     if (StreamExtractor.ExtractorType == ExtractorType.MSS)
@@ -330,10 +330,10 @@ internal class SimpleLiveRecordManager2
                 var path = Path.Combine(tmpDir, filename + $".{streamSpec.Extension ?? "clip"}.tmp");
                 var result = await Downloader.DownloadSegmentAsync(seg, path, speedContainer, headers);
                 FileDic[seg] = result;
-                if (result != null && result.Success)
+                if (result is { Success: true })
                     task.Increment(1);
                 // 实时解密
-                if (seg.IsEncrypted && DownloaderConfig.MyOptions.MP4RealTimeDecryption && result != null && result.Success && !string.IsNullOrEmpty(currentKID))
+                if (seg.IsEncrypted && DownloaderConfig.MyOptions.MP4RealTimeDecryption && result is { Success: true } && !string.IsNullOrEmpty(currentKID))
                 {
                     var enc = result.ActualFilePath;
                     var dec = Path.Combine(Path.GetDirectoryName(enc)!, Path.GetFileNameWithoutExtension(enc) + "_dec" + Path.GetExtension(enc));
@@ -347,14 +347,13 @@ internal class SimpleLiveRecordManager2
             });
 
             // 自动修复VTT raw字幕
-            if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
+            if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec is { MediaType: Common.Enum.MediaType.SUBTITLES, Extension: not null } && streamSpec.Extension.Contains("vtt"))
-                                                           && streamSpec.Extension != null && streamSpec.Extension.Contains("vtt"))
             {
                 // 排序字幕并修正时间戳
-                var keys = FileDic.Keys.OrderBy(k => k.Index);
+                var keys = FileDic.Keys.OrderBy(k => k.Index).ToList();
                 foreach (var seg in keys)
                 {
-                    var vttContent = File.ReadAllText(FileDic[seg]!.ActualFilePath);
+                    var vttContent = await File.ReadAllTextAsync(FileDic[seg]!.ActualFilePath);
                     var waitCount = 0;
                     while (DownloaderConfig.MyOptions.LiveFixVttByAudio && audioStart == null && waitCount++ < 5)
                     {
@@ -376,7 +375,7 @@ internal class SimpleLiveRecordManager2
             if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
                                                            && streamSpec.Codecs != "stpp" && streamSpec.Extension != null && streamSpec.Extension.Contains("m4s"))
             {
-                var initFile = FileDic.Values.Where(v => Path.GetFileName(v!.ActualFilePath).StartsWith("_init")).FirstOrDefault();
+                var initFile = FileDic.Values.FirstOrDefault(v => Path.GetFileName(v!.ActualFilePath).StartsWith("_init"));
                 var iniFileBytes = File.ReadAllBytes(initFile!.ActualFilePath);
                 var (sawVtt, timescale) = MP4VttUtil.CheckInit(iniFileBytes);
                 if (sawVtt)
@@ -396,10 +395,9 @@ internal class SimpleLiveRecordManager2
             }
 
             // 自动修复TTML raw字幕
-            if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
+            if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec is { MediaType: Common.Enum.MediaType.SUBTITLES, Extension: not null } && streamSpec.Extension.Contains("ttml"))
-                                                           && streamSpec.Extension != null && streamSpec.Extension.Contains("ttml"))
             {
-                var keys = FileDic.OrderBy(s => s.Key.Index).Where(v => v.Value!.ActualFilePath.EndsWith(".m4s")).Select(s => s.Key);
+                var keys = FileDic.OrderBy(s => s.Key.Index).Where(v => v.Value!.ActualFilePath.EndsWith(".m4s")).Select(s => s.Key).ToList();
                 if (firstSub)
                 {
                     if (baseTimestamp != 0)
@@ -437,9 +435,8 @@ internal class SimpleLiveRecordManager2
             }
 
             // 自动修复TTML mp4字幕
-            if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
+            if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec is { MediaType: Common.Enum.MediaType.SUBTITLES, Extension: not null } && streamSpec.Extension.Contains("m4s")
-                                                           && streamSpec.Extension != null && streamSpec.Extension.Contains("m4s")
+                && streamSpec.Codecs != null && streamSpec.Codecs.Contains("stpp"))
-                                                           && streamSpec.Codecs != null && streamSpec.Codecs.Contains("stpp"))
             {
                 // sawTtml暂时不判断
                 // var initFile = FileDic.Values.Where(v => Path.GetFileName(v!.ActualFilePath).StartsWith("_init")).FirstOrDefault();
@@ -498,12 +495,11 @@ internal class SimpleLiveRecordManager2
                 // 合并
                 var outputExt = "." + streamSpec.Extension;
                 if (streamSpec.Extension == null) outputExt = ".ts";
-                else if (streamSpec.MediaType == MediaType.AUDIO && streamSpec.Extension == "m4s") outputExt = ".m4a";
+                else if (streamSpec is { MediaType: MediaType.AUDIO, Extension: "m4s" }) outputExt = ".m4a";
                 else if (streamSpec.MediaType != MediaType.SUBTITLES && streamSpec.Extension == "m4s") outputExt = ".mp4";
                 else if (streamSpec.MediaType == MediaType.SUBTITLES)
                 {
-                    if (DownloaderConfig.MyOptions.SubtitleFormat == Enum.SubtitleFormat.SRT) outputExt = ".srt";
+                    outputExt = DownloaderConfig.MyOptions.SubtitleFormat == Enum.SubtitleFormat.SRT ? ".srt" : ".vtt";
-                    else outputExt = ".vtt";
                 }
 
                 var output = Path.Combine(saveDir, saveName + outputExt);
@@ -536,7 +532,7 @@ internal class SimpleLiveRecordManager2
                         fileOutputStream = PipeUtil.CreatePipe(pipeName);
                         Logger.InfoMarkUp($"{ResString.namedPipeCreated} [cyan]{pipeName.EscapeMarkup()}[/]");
                         PipeSteamNamesDic[task.Id] = pipeName;
-                        if (PipeSteamNamesDic.Count == SelectedSteams.Where(x => x.MediaType != MediaType.SUBTITLES).Count()) 
+                        if (PipeSteamNamesDic.Count == SelectedSteams.Count(x => x.MediaType != MediaType.SUBTITLES)) 
                         {
                             var names = PipeSteamNamesDic.OrderBy(i => i.Key).Select(k => k.Value).ToArray();
                             Logger.WarnMarkUp($"{ResString.namedPipeMux} [deepskyblue1]{Path.GetFileName(output).EscapeMarkup()}[/]");
@@ -622,24 +618,23 @@ internal class SimpleLiveRecordManager2
                 break;
         }
 
-        if (fileOutputStream != null)
+        if (fileOutputStream == null) return true;
+        
+        if (!DownloaderConfig.MyOptions.LivePipeMux)
         {
-            if (!DownloaderConfig.MyOptions.LivePipeMux)
+            // 记录所有文件信息
+            OutputFiles.Add(new OutputFile()
             {
-                // 记录所有文件信息
+                Index = task.Id,
-                OutputFiles.Add(new OutputFile()
+                FilePath = (fileOutputStream as FileStream)!.Name,
-                {
+                LangCode = streamSpec.Language,
-                    Index = task.Id,
+                Description = streamSpec.Name,
-                    FilePath = (fileOutputStream as FileStream)!.Name,
+                Mediainfos = mediaInfos,
-                    LangCode = streamSpec.Language,
+                MediaType = streamSpec.MediaType,
-                    Description = streamSpec.Name,
+            });
-                    Mediainfos = mediaInfos,
-                    MediaType = streamSpec.MediaType,
-                });
-            }
-            fileOutputStream.Close();
-            fileOutputStream.Dispose();
         }
+        fileOutputStream.Close();
+        fileOutputStream.Dispose();
 
         return true;
     }
@@ -648,78 +643,76 @@ internal class SimpleLiveRecordManager2
     {
         while (!STOP_FLAG)
         {
-            if (WAIT_SEC != 0)
+            if (WAIT_SEC == 0) continue;
+            
+            // 1. MPD 所有URL相同 单次请求即可获得所有轨道的信息
+            // 2. M3U8 所有URL不同 才需要多次请求
+            await Parallel.ForEachAsync(dic, async (dic, _) =>
             {
-                // 1. MPD 所有URL相同 单次请求即可获得所有轨道的信息
+                var streamSpec = dic.Key;
-                // 2. M3U8 所有URL不同 才需要多次请求
+                var task = dic.Value;
 
-                await Parallel.ForEachAsync(dic, async (dic, _) =>
+                // 达到上限时 不需要刷新了
+                if (RecordLimitReachedDic[task.Id])
+                    return;
+
+                var allHasDatetime = streamSpec.Playlist!.MediaParts[0].MediaSegments.All(s => s.DateTime != null);
+                if (!SamePathDic.ContainsKey(task.Id))
                 {
-                    var streamSpec = dic.Key;
+                    var allName = streamSpec.Playlist!.MediaParts[0].MediaSegments.Select(s => OtherUtil.GetFileNameFromInput(s.Url, false));
-                    var task = dic.Value;
+                    var allSamePath = allName.Count() > 1 && allName.Distinct().Count() == 1;
-
+                    SamePathDic[task.Id] = allSamePath;
-                    // 达到上限时 不需要刷新了
-                    if (RecordLimitReachedDic[task.Id])
-                        return;
-
-                    var allHasDatetime = streamSpec.Playlist!.MediaParts[0].MediaSegments.All(s => s.DateTime != null);
-                    if (!SamePathDic.ContainsKey(task.Id))
-                    {
-                        var allName = streamSpec.Playlist!.MediaParts[0].MediaSegments.Select(s => OtherUtil.GetFileNameFromInput(s.Url, false));
-                        var allSamePath = allName.Count() > 1 && allName.Distinct().Count() == 1;
-                        SamePathDic[task.Id] = allSamePath;
-                    }
-                    // 过滤不需要下载的片段
-                    FilterMediaSegments(streamSpec, task, allHasDatetime, SamePathDic[task.Id]);
-                    var newList = streamSpec.Playlist!.MediaParts[0].MediaSegments;
-                    if (newList.Count > 0)
-                    {
-                        task.MaxValue += newList.Count;
-                        // 推送给消费者
-                        await BlockDic[task.Id].SendAsync(newList);
-                        // 更新最新链接
-                        LastFileNameDic[task.Id] = GetSegmentName(newList.Last(), allHasDatetime, SamePathDic[task.Id]);
-                        // 尝试更新时间戳
-                        var dt = newList.Last().DateTime;
-                        DateTimeDic[task.Id] = dt != null ? GetUnixTimestamp(dt.Value) : 0L;
-                        // 累加已获取到的时长
-                        RefreshedDurDic[task.Id] += (int)newList.Sum(s => s.Duration);
-                    }
-
-                    if (!STOP_FLAG && RefreshedDurDic[task.Id] >= DownloaderConfig.MyOptions.LiveRecordLimit?.TotalSeconds)
-                    {
-                        RecordLimitReachedDic[task.Id] = true;
-                    }
-
-                    // 检测时长限制
-                    if (!STOP_FLAG && RecordLimitReachedDic.Values.All(x => x == true))
-                    {
-                        Logger.WarnMarkUp($"[darkorange3_1]{ResString.liveLimitReached}[/]");
-                        STOP_FLAG = true;
-                        CancellationTokenSource.Cancel();
-                    }
-                });
-
-                try
-                {
-                    // Logger.WarnMarkUp($"wait {waitSec}s");
-                    if (!STOP_FLAG) await Task.Delay(WAIT_SEC * 1000, CancellationTokenSource.Token);
-                    // 刷新列表
-                    if (!STOP_FLAG) await StreamExtractor.RefreshPlayListAsync(dic.Keys.ToList());
                 }
-                catch (OperationCanceledException oce) when (oce.CancellationToken == CancellationTokenSource.Token)
+                // 过滤不需要下载的片段
+                FilterMediaSegments(streamSpec, task, allHasDatetime, SamePathDic[task.Id]);
+                var newList = streamSpec.Playlist!.MediaParts[0].MediaSegments;
+                if (newList.Count > 0)
                 {
-                    // 不需要做事
+                    task.MaxValue += newList.Count;
+                    // 推送给消费者
+                    await BlockDic[task.Id].SendAsync(newList);
+                    // 更新最新链接
+                    LastFileNameDic[task.Id] = GetSegmentName(newList.Last(), allHasDatetime, SamePathDic[task.Id]);
+                    // 尝试更新时间戳
+                    var dt = newList.Last().DateTime;
+                    DateTimeDic[task.Id] = dt != null ? GetUnixTimestamp(dt.Value) : 0L;
+                    // 累加已获取到的时长
+                    RefreshedDurDic[task.Id] += (int)newList.Sum(s => s.Duration);
                 }
-                catch (Exception e)
+
+                if (!STOP_FLAG && RefreshedDurDic[task.Id] >= DownloaderConfig.MyOptions.LiveRecordLimit?.TotalSeconds)
                 {
-                    Logger.ErrorMarkUp(e);
+                    RecordLimitReachedDic[task.Id] = true;
+                }
+
+                // 检测时长限制
+                if (!STOP_FLAG && RecordLimitReachedDic.Values.All(x => x))
+                {
+                    Logger.WarnMarkUp($"[darkorange3_1]{ResString.liveLimitReached}[/]");
                     STOP_FLAG = true;
-                    // 停止所有Block
+                    CancellationTokenSource.Cancel();
-                    foreach (var target in BlockDic.Values)
+                }
-                    {
+            });
-                        target.Complete();
+
-                    }
+            try
+            {
+                // Logger.WarnMarkUp($"wait {waitSec}s");
+                if (!STOP_FLAG) await Task.Delay(WAIT_SEC * 1000, CancellationTokenSource.Token);
+                // 刷新列表
+                if (!STOP_FLAG) await StreamExtractor.RefreshPlayListAsync(dic.Keys.ToList());
+            }
+            catch (OperationCanceledException oce) when (oce.CancellationToken == CancellationTokenSource.Token)
+            {
+                // 不需要做事
+            }
+            catch (Exception e)
+            {
+                Logger.ErrorMarkUp(e);
+                STOP_FLAG = true;
+                // 停止所有Block
+                foreach (var target in BlockDic.Values)
+                {
+                    target.Complete();
                 }
             }
         }
@@ -783,7 +776,7 @@ internal class SimpleLiveRecordManager2
             Logger.WarnMarkUp($"set refresh interval to {WAIT_SEC} seconds");
         }
         // 如果没有选中音频 取消通过音频修复vtt时间轴
-        if (!SelectedSteams.Any(x => x.MediaType == MediaType.AUDIO))
+        if (SelectedSteams.All(x => x.MediaType != MediaType.AUDIO))
         {
             DownloaderConfig.MyOptions.LiveFixVttByAudio = false;
         }
@@ -839,7 +832,7 @@ internal class SimpleLiveRecordManager2
 
             DownloaderConfig.MyOptions.ConcurrentDownload = true;
             DownloaderConfig.MyOptions.MP4RealTimeDecryption = true;
-            DownloaderConfig.MyOptions.LiveRecordLimit = DownloaderConfig.MyOptions.LiveRecordLimit ?? TimeSpan.MaxValue;
+            DownloaderConfig.MyOptions.LiveRecordLimit ??= TimeSpan.MaxValue;
             if (DownloaderConfig.MyOptions is { MP4RealTimeDecryption: true, DecryptionEngine: not DecryptEngine.SHAKA_PACKAGER, Keys.Length: > 0 })
                 Logger.WarnMarkUp($"[darkorange3_1]{ResString.realTimeDecMessage}[/]");
             var limit = DownloaderConfig.MyOptions.LiveRecordLimit;
@@ -865,7 +858,7 @@ internal class SimpleLiveRecordManager2
         var success = Results.Values.All(v => v == true);
 
         // 删除临时文件夹
-        if (!DownloaderConfig.MyOptions.SkipMerge && DownloaderConfig.MyOptions.DelAfterDone && success)
+        if (DownloaderConfig.MyOptions is { SkipMerge: false, DelAfterDone: true } && success)
         {
             foreach (var item in StreamExtractor.RawFiles)
             {

src/N_m3u8DL-RE/Downloader/SimpleDownloader.cs

@@ -25,23 +25,25 @@ internal class SimpleDownloader : IDownloader
     {
         var url = segment.Url;
         var (des, dResult) = await DownClipAsync(url, savePath, speedContainer, segment.StartRange, segment.StopRange, headers, DownloaderConfig.MyOptions.DownloadRetryCount);
-        if (dResult != null && dResult.Success && dResult.ActualFilePath != des)
+        if (dResult is { Success: true } && dResult.ActualFilePath != des)
         {
-            if (segment.EncryptInfo != null)
+            switch (segment.EncryptInfo.Method)
             {
-                if (segment.EncryptInfo.Method == EncryptMethod.AES_128)
+                case EncryptMethod.AES_128:
                 {
                     var key = segment.EncryptInfo.Key;
                     var iv = segment.EncryptInfo.IV;
                     AESUtil.AES128Decrypt(dResult.ActualFilePath, key!, iv!);
+                    break;
                 }
-                else if (segment.EncryptInfo.Method == EncryptMethod.AES_128_ECB)
+                case EncryptMethod.AES_128_ECB:
                 {
                     var key = segment.EncryptInfo.Key;
                     var iv = segment.EncryptInfo.IV;
                     AESUtil.AES128Decrypt(dResult.ActualFilePath, key!, iv!, System.Security.Cryptography.CipherMode.ECB);
+                    break;
                 }
-                else if (segment.EncryptInfo.Method == EncryptMethod.CHACHA20)
+                case EncryptMethod.CHACHA20:
                 {
                     var key = segment.EncryptInfo.Key;
                     var nonce = segment.EncryptInfo.IV;
@@ -49,22 +51,22 @@ internal class SimpleDownloader : IDownloader
                     var fileBytes = File.ReadAllBytes(dResult.ActualFilePath);
                     var decrypted = ChaCha20Util.DecryptPer1024Bytes(fileBytes, key!, nonce!);
                     await File.WriteAllBytesAsync(dResult.ActualFilePath, decrypted);
+                    break;
                 }
-                else if (segment.EncryptInfo.Method == EncryptMethod.SAMPLE_AES_CTR)
+                case EncryptMethod.SAMPLE_AES_CTR:
-                {
                     // throw new NotSupportedException("SAMPLE-AES-CTR");
-                }
+                    break;
+            }
 
-                // Image头处理
+            // Image头处理
-                if (dResult.ImageHeader)
+            if (dResult.ImageHeader)
-                {
+            {
-                    await ImageHeaderUtil.ProcessAsync(dResult.ActualFilePath);
+                await ImageHeaderUtil.ProcessAsync(dResult.ActualFilePath);
-                }
+            }
-                // Gzip解压
+            // Gzip解压
-                if (dResult.GzipHeader)
+            if (dResult.GzipHeader)
-                {
+            {
-                    await OtherUtil.DeGzipFileAsync(dResult.ActualFilePath);
+                await OtherUtil.DeGzipFileAsync(dResult.ActualFilePath);
-                }
             }
 
             // 处理完成后改名
@@ -99,14 +101,15 @@ internal class SimpleDownloader : IDownloader
             }
 
             // 另起线程进行监控
+            var cts = cancellationTokenSource;
             using var watcher = Task.Factory.StartNew(async () =>
             {
                 while (true)
                 {
-                    if (cancellationTokenSource == null || cancellationTokenSource.IsCancellationRequested) break;
+                    if (cts.IsCancellationRequested) break;
                     if (speedContainer.ShouldStop)
                     {
-                        cancellationTokenSource.Cancel();
+                        cts.Cancel();
                         Logger.DebugMarkUp("Cancel...");
                         break;
                     }
@@ -123,7 +126,7 @@ internal class SimpleDownloader : IDownloader
         catch (Exception ex)
         {
             Logger.DebugMarkUp($"[grey]{ex.Message.EscapeMarkup()} retryCount: {retryCount}[/]");
-            Logger.Debug(url + " " + ex.ToString());
+            Logger.Debug(url + " " + ex);
             Logger.Extra($"Ah oh!{Environment.NewLine}RetryCount => {retryCount}{Environment.NewLine}Exception  => {ex.Message}{Environment.NewLine}Url        => {url}");
             if (retryCount-- > 0)
             {

src/N_m3u8DL-RE/Entity/DownloadResult.cs

@@ -1,15 +1,8 @@
-using System;
+namespace N_m3u8DL_RE.Entity;
-using System.Collections.Concurrent;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace N_m3u8DL_RE.Entity;
 
 internal class DownloadResult
 {
-    public bool Success { get => (ActualContentLength != null && RespContentLength != null) ? (RespContentLength == ActualContentLength) : (ActualContentLength == null ? false : true); }
+    public bool Success => (ActualContentLength != null && RespContentLength != null) ? (RespContentLength == ActualContentLength) : (ActualContentLength != null);
     public long? RespContentLength { get; set; }
     public long? ActualContentLength { get; set; }
     public bool ImageHeader { get; set; } = false; // 图片伪装

src/N_m3u8DL-RE/Entity/OutputFile.cs

@@ -9,5 +9,5 @@ internal class OutputFile
     public required string FilePath { get; set; }
     public string? LangCode { get; set; }
     public string? Description { get; set; }
-    public List<Mediainfo> Mediainfos { get; set; } = new();
+    public List<Mediainfo> Mediainfos { get; set; } = [];
 }

src/N_m3u8DL-RE/Entity/SpeedContainer.cs

@@ -1,13 +1,4 @@
-using NiL.JS.Statements;
+namespace N_m3u8DL_RE.Entity;
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Drawing;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace N_m3u8DL_RE.Entity;
 
 internal class SpeedContainer
 {
@@ -24,7 +15,7 @@ internal class SpeedContainer
 
     private long _downloaded = 0;
     private long _Rdownloaded = 0;
-    public long Downloaded { get => _downloaded; }
+    public long Downloaded => _downloaded;
 
     public int AddLowSpeedCount()
     {

src/N_m3u8DL-RE/Entity/StreamFilter.cs

@@ -46,6 +46,6 @@ public class StreamFilter
         if (BandwidthMax != null) sb.Append($"{nameof(BandwidthMax)}: {BandwidthMax} ");
         if (Role.HasValue) sb.Append($"Role: {Role} ");
 
-        return sb.ToString() + $"For: {For}";
+        return sb + $"For: {For}";
     }
 }

src/N_m3u8DL-RE/Program.cs

@@ -13,7 +13,6 @@ using N_m3u8DL_RE.Util;
 using N_m3u8DL_RE.DownloadManager;
 using N_m3u8DL_RE.CommandLine;
 using System.Net;
-using System.Net.Http.Headers;
 using N_m3u8DL_RE.Enum;
 
 namespace N_m3u8DL_RE;
@@ -26,7 +25,7 @@ internal class Program
         if (OperatingSystem.IsWindows()) 
         {
             var osVersion = Environment.OSVersion.Version;
-            if (osVersion.Major < 6 || (osVersion.Major == 6 && osVersion.Minor == 0))
+            if (osVersion.Major < 6 || osVersion is { Major: 6, Minor: 0 })
             {
                 Environment.SetEnvironmentVariable("DOTNET_SYSTEM_GLOBALIZATION_INVARIANT", "1");
             }
@@ -38,7 +37,7 @@ internal class Program
 
         string loc = ResString.CurrentLoc;
         string currLoc = Thread.CurrentThread.CurrentUICulture.Name;
-        if (currLoc == "zh-CN" || currLoc == "zh-SG") loc = "zh-CN";
+        if (currLoc is "zh-CN" or "zh-SG") loc = "zh-CN";
         else if (currLoc.StartsWith("zh-")) loc = "zh-TW";
 
         // 处理用户-h等请求
@@ -147,33 +146,36 @@ internal class Program
         // 预先检查
         if (option.Keys is { Length: > 0 } || option.KeyTextFile != null)
         {
-            if (string.IsNullOrEmpty(option.DecryptionBinaryPath))
+            if (!string.IsNullOrEmpty(option.DecryptionBinaryPath) && !File.Exists(option.DecryptionBinaryPath))
             {
-                if (option.DecryptionEngine is DecryptEngine.SHAKA_PACKAGER)
+                throw new FileNotFoundException(option.DecryptionBinaryPath);
+            }
+            switch (option.DecryptionEngine)
+            {
+                case DecryptEngine.SHAKA_PACKAGER:
                 {
                     var file = GlobalUtil.FindExecutable("shaka-packager");
                     var file2 = GlobalUtil.FindExecutable("packager-linux-x64");
                     var file3 = GlobalUtil.FindExecutable("packager-osx-x64");
                     var file4 = GlobalUtil.FindExecutable("packager-win-x64");
-                    if (file == null && file2 == null && file3 == null && file4 == null) throw new FileNotFoundException(ResString.shakaPackagerNotFound);
+                    if (file == null && file2 == null && file3 == null && file4 == null)
+                        throw new FileNotFoundException(ResString.shakaPackagerNotFound);
                     option.DecryptionBinaryPath = file ?? file2 ?? file3 ?? file4;
                     Logger.Extra($"shaka-packager => {option.DecryptionBinaryPath}");
+                    break;
                 }
-                else if (option.DecryptionEngine is DecryptEngine.MP4DECRYPT)
+                case DecryptEngine.MP4DECRYPT:
                 {
                     var file = GlobalUtil.FindExecutable("mp4decrypt");
                     if (file == null) throw new FileNotFoundException(ResString.mp4decryptNotFound);
                     option.DecryptionBinaryPath = file;
                     Logger.Extra($"mp4decrypt => {option.DecryptionBinaryPath}");
+                    break;
                 }
-                else
+                case DecryptEngine.FFMPEG:
-                {
+                default:
                     option.DecryptionBinaryPath = option.FFmpegBinaryPath;
-                }
+                    break;
-            }
-            else if (!File.Exists(option.DecryptionBinaryPath))
-            {
-                throw new FileNotFoundException(option.DecryptionBinaryPath);
             }
         }
 
@@ -283,7 +285,7 @@ internal class Program
 
         if (option.AutoSelect)
         {
-            if (basicStreams.Any())
+            if (basicStreams.Count != 0)
                 selectedStreams.Add(basicStreams.First());
             var langs = audios.DistinctBy(a => a.Language).Select(a => a.Language);
             foreach (var lang in langs)
@@ -309,7 +311,7 @@ internal class Program
             selectedStreams = FilterUtil.SelectStreams(lists);
         }
 
-        if (!selectedStreams.Any())
+        if (selectedStreams.Count == 0)
             throw new Exception(ResString.noStreamsToDownload);
 
         // HLS: 选中流中若有没加载出playlist的，加载playlist
@@ -363,7 +365,7 @@ internal class Program
         Logger.InfoMarkUp(ResString.saveName + $"[deepskyblue1]{option.SaveName.EscapeMarkup()}[/]");
 
         // 开始MuxAfterDone后自动使用二进制版
-        if (!option.BinaryMerge && option.MuxAfterDone)
+        if (option is { BinaryMerge: false, MuxAfterDone: true })
         {
             option.BinaryMerge = true;
             Logger.WarnMarkUp($"[darkorange3_1]{ResString.autoBinaryMerge6}[/]");
@@ -446,24 +448,21 @@ internal class Program
     static async Task<string> Get302Async(string url)
     {
         // this allows you to set the settings so that we can get the redirect url
-        var handler = new HttpClientHandler()
+        var handler = new HttpClientHandler
         {
             AllowAutoRedirect = false
         };
-        string redirectedUrl = "";
+        var redirectedUrl = "";
-        using (HttpClient client = new(handler))
+        using var client = new HttpClient(handler);
-        using (HttpResponseMessage response = await client.GetAsync(url))
+        using var response = await client.GetAsync(url);
-        using (HttpContent content = response.Content)
+        using var content = response.Content;
+        // ... Read the response to see if we have the redirected url
+        if (response.StatusCode != HttpStatusCode.Found) return redirectedUrl;
+        
+        var headers = response.Headers;
+        if (headers.Location != null)
         {
-            // ... Read the response to see if we have the redirected url
+            redirectedUrl = headers.Location.AbsoluteUri;
-            if (response.StatusCode == System.Net.HttpStatusCode.Found)
-            {
-                HttpResponseHeaders headers = response.Headers;
-                if (headers != null && headers.Location != null)
-                {
-                    redirectedUrl = headers.Location.AbsoluteUri;
-                }
-            }
         }
 
         return redirectedUrl;

src/N_m3u8DL-RE/Util/DownloadUtil.cs

@@ -25,7 +25,7 @@ internal static class DownloadUtil
         {
             var buffer = new byte[expect];
             _ = await inputStream.ReadAsync(buffer);
-            await outputStream.WriteAsync(buffer, 0, buffer.Length);
+            await outputStream.WriteAsync(buffer);
             speedContainer.Add(buffer.Length);
         }
         return new DownloadResult()
@@ -81,7 +81,7 @@ internal static class DownloadUtil
             {
                 HttpResponseHeaders respHeaders = response.Headers;
                 Logger.Debug(respHeaders.ToString());
-                if (respHeaders != null && respHeaders.Location != null)
+                if (respHeaders.Location != null)
                 {
                     var redirectedUrl = "";
                     if (!respHeaders.Location.IsAbsoluteUri)
@@ -108,7 +108,7 @@ internal static class DownloadUtil
 
             size = await responseStream.ReadAsync(buffer, cancellationTokenSource.Token);
             speedContainer.Add(size);
-            await stream.WriteAsync(buffer, 0, size);
+            await stream.WriteAsync(buffer.AsMemory(0, size));
             // 检测imageHeader
             bool imageHeader = ImageHeaderUtil.IsImageHeader(buffer);
             // 检测GZip（For DDP Audio）
@@ -117,7 +117,7 @@ internal static class DownloadUtil
             while ((size = await responseStream.ReadAsync(buffer, cancellationTokenSource.Token)) > 0)
             {
                 speedContainer.Add(size);
-                await stream.WriteAsync(buffer, 0, size);
+                await stream.WriteAsync(buffer.AsMemory(0, size));
                 // 限速策略
                 while (speedContainer.Downloaded > speedContainer.SpeedLimit)
                 {

src/N_m3u8DL-RE/Util/FilterUtil.cs

@@ -65,7 +65,7 @@ public static class FilterUtil
 
     public static List<StreamSpec> DoFilterDrop(IEnumerable<StreamSpec> lists, StreamFilter? filter)
     {
-        if (filter == null) return new List<StreamSpec>(lists);
+        if (filter == null) return [..lists];
 
         var inputs = lists.Where(_ => true);
         var selected = DoFilterKeep(lists, filter);
@@ -93,9 +93,8 @@ public static class FilterUtil
                 .UseConverter(x =>
                 {
                     if (x.Name != null && x.Name.StartsWith("__"))
-                        return $"[darkslategray1]{x.Name.Substring(2)}[/]";
+                        return $"[darkslategray1]{x.Name[2..]}[/]";
-                    else
+                    return x.ToString().EscapeMarkup().RemoveMarkup();
-                        return x.ToString().EscapeMarkup().RemoveMarkup();
                 })
                 .Required()
                 .PageSize(10)
@@ -107,12 +106,12 @@ public static class FilterUtil
         var first = streamSpecs.First();
         prompt.Select(first);
 
-        if (basicStreams.Any())
+        if (basicStreams.Count != 0)
         {
             prompt.AddChoiceGroup(new StreamSpec() { Name = "__Basic" }, basicStreams);
         }
 
-        if (audios.Any())
+        if (audios.Count != 0)
         {
             prompt.AddChoiceGroup(new StreamSpec() { Name = "__Audio" }, audios);
             // 默认音轨
@@ -121,7 +120,7 @@ public static class FilterUtil
                 prompt.Select(audios.First(a => a.GroupId == first.AudioId));
             }
         }
-        if (subs.Any())
+        if (subs.Count != 0)
         {
             prompt.AddChoiceGroup(new StreamSpec() { Name = "__Subtitle" }, subs);
             // 默认字幕轨

src/N_m3u8DL-RE/Util/LargeSingleFileSplitUtil.cs

@@ -80,7 +80,7 @@ internal static class LargeSingleFileSplitUtil
     // 此函数主要是切片下载逻辑
     private static List<Clip> GetAllClips(string url, long fileSize)
     {
-        List<Clip> clips = new();
+        List<Clip> clips = [];
         int index = 0;
         long counter = 0;
         int perSize = 10 * 1024 * 1024;

src/N_m3u8DL-RE/Util/MP4DecryptUtil.cs

@@ -7,7 +7,7 @@ using N_m3u8DL_RE.Enum;
 
 namespace N_m3u8DL_RE.Util;
 
-internal static class MP4DecryptUtil
+internal static partial class MP4DecryptUtil
 {
     private static readonly string ZeroKid = "00000000000000000000000000000000";
     public static async Task<bool> DecryptAsync(DecryptEngine decryptEngine, string bin, string[]? keys, string source, string dest, string? kid, string init = "", bool isMultiDRM=false)
@@ -29,7 +29,7 @@ internal static class MP4DecryptUtil
         if (!string.IsNullOrEmpty(kid))
         {
             var test = keyPairs.Where(k => k.StartsWith(kid)).ToList();
-            if (test.Any()) keyPair = test.First();
+            if (test.Count != 0) keyPair = test.First();
         }
 
         // Apple
@@ -159,11 +159,10 @@ internal static class MP4DecryptUtil
             using var reader = new StreamReader(stream);
             while (await reader.ReadLineAsync() is { } line)
             {
-                if (line.Trim().StartsWith(kid))
+                if (!line.Trim().StartsWith(kid)) continue;
-                {
+                
-                    Logger.InfoMarkUp($"[green]OK[/] [grey]{line.Trim()}[/]");
+                Logger.InfoMarkUp($"[green]OK[/] [grey]{line.Trim()}[/]");
-                    return line.Trim();
+                return line.Trim();
-                }
             }
         }
         catch (Exception ex)
@@ -192,7 +191,7 @@ internal static class MP4DecryptUtil
 
     public static string? ReadInitShaka(string output, string bin)
     {
-        Regex shakaKeyIdRegex = new("Key for key_id=([0-9a-f]+) was not found");
+        Regex shakaKeyIdRegex = KidOutputRegex();
 
         // TODO: handle the case that shaka packager actually decrypted (key ID == ZeroKid)
         //       - stop process
@@ -214,4 +213,7 @@ internal static class MP4DecryptUtil
         p.WaitForExit();
         return shakaKeyIdRegex.Match(errorOutput).Groups[1].Value;
     }
+
+    [GeneratedRegex("Key for key_id=([0-9a-f]+) was not found")]
+    private static partial Regex KidOutputRegex();
 }

src/N_m3u8DL-RE/Util/MediainfoUtil.cs

@@ -8,23 +8,23 @@ internal static partial class MediainfoUtil
 {
     [GeneratedRegex("  Stream #.*")]
     private static partial Regex TextRegex();
-    [GeneratedRegex("#0:\\d(\\[0x\\w+?\\])")]
+    [GeneratedRegex(@"#0:\d(\[0x\w+?\])")]
     private static partial Regex IdRegex();
     [GeneratedRegex(": (\\w+): (.*)")]
     private static partial Regex TypeRegex();
     [GeneratedRegex("(.*?)(,|$)")]
     private static partial Regex BaseInfoRegex();
-    [GeneratedRegex(" \\/ 0x\\w+")]
+    [GeneratedRegex(@" \/ 0x\w+")]
     private static partial Regex ReplaceRegex();
-    [GeneratedRegex("\\d{2,}x\\d+")]
+    [GeneratedRegex(@"\d{2,}x\d+")]
     private static partial Regex ResRegex();
-    [GeneratedRegex("\\d+ kb\\/s")]
+    [GeneratedRegex(@"\d+ kb\/s")]
     private static partial Regex BitrateRegex();
-    [GeneratedRegex("(\\d+(\\.\\d+)?) fps")]
+    [GeneratedRegex(@"(\d+(\.\d+)?) fps")]
     private static partial Regex FpsRegex();
-    [GeneratedRegex("DOVI configuration record.*profile: (\\d).*compatibility id: (\\d)")]
+    [GeneratedRegex(@"DOVI configuration record.*profile: (\d).*compatibility id: (\d)")]
     private static partial Regex DoViRegex();
-    [GeneratedRegex("Duration.*?start: (\\d+\\.?\\d{0,3})")]
+    [GeneratedRegex(@"Duration.*?start: (\d+\.?\d{0,3})")]
     private static partial Regex StartRegex();
 
     public static async Task<List<Mediainfo>> ReadInfoAsync(string binary, string file)

src/N_m3u8DL-RE/Util/MergeUtil.cs

@@ -68,20 +68,16 @@ internal static class MergeUtil
     public static string[] PartialCombineMultipleFiles(string[] files)
     {
         var newFiles = new List<string>();
-        int div = 0;
+        var div = files.Length <= 90000 ? 100 : 200;
-        if (files.Length <= 90000)
-            div = 100;
-        else
-            div = 200;
 
-        string outputName = Path.Combine(Path.GetDirectoryName(files[0])!, "T");
+        var outputName = Path.Combine(Path.GetDirectoryName(files[0])!, "T");
-        int index = 0; // 序号
+        var index = 0; // 序号
 
         // 按照div的容量分割为小数组
-        string[][] li = Enumerable.Range(0, files.Count() / div + 1).Select(x => files.Skip(x * div).Take(div).ToArray()).ToArray();
+        var li = Enumerable.Range(0, files.Length / div + 1).Select(x => files.Skip(x * div).Take(div).ToArray()).ToArray();
         foreach (var items in li)
         {
-            if (!items.Any())
+            if (items.Length == 0)
                 continue;
             var output = outputName + index.ToString("0000") + ".ts";
             CombineMultipleFilesIntoSingleFile(items, output);

src/N_m3u8DL-RE/Util/OtherUtil.cs

@@ -4,7 +4,7 @@ using System.Text.RegularExpressions;
 
 namespace N_m3u8DL_RE.Util;
 
-internal static class OtherUtil
+internal static partial class OtherUtil
 {
     public static Dictionary<string, string> SplitHeaderArrayToDic(string[]? headers)
     {
@@ -25,13 +25,9 @@ internal static class OtherUtil
 
     private static readonly char[] InvalidChars = "34,60,62,124,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,58,42,63,92,47"
         .Split(',').Select(s => (char)int.Parse(s)).ToArray();
-    public static string GetValidFileName(string input, string re = ".", bool filterSlash = false)
+    public static string GetValidFileName(string input, string re = "_", bool filterSlash = false)
     {
-        string title = input;
+        var title = InvalidChars.Aggregate(input, (current, invalidChar) => current.Replace(invalidChar.ToString(), re));
-        foreach (char invalidChar in InvalidChars)
-        {
-            title = title.Replace(invalidChar.ToString(), re);
-        }
         if (filterSlash)
         {
             title = title.Replace("/", re);
@@ -98,7 +94,7 @@ internal static class OtherUtil
     /// <exception cref="ArgumentException"></exception>
     public static double ParseSeconds(string timeStr)
     {
-        var pattern = new Regex(@"^(?:(\d+)h)?(?:(\d+)m)?(?:(\d+)s)?$");
+        var pattern = TimeStrRegex();
 
         var match = pattern.Match(timeStr);
 
@@ -171,4 +167,7 @@ internal static class OtherUtil
             _ => throw new ArgumentException($"unknown format: {muxFormat}")
         };
     }
+
+    [GeneratedRegex(@"^(?:(\d+)h)?(?:(\d+)m)?(?:(\d+)s)?$")]
+    private static partial Regex TimeStrRegex();
 }

src/N_m3u8DL-RE/Util/PipeUtil.cs

@@ -14,24 +14,22 @@ internal static class PipeUtil
         {
             return new NamedPipeServerStream(pipeName, PipeDirection.InOut);
         }
-        else
+
+        var path = Path.Combine(Path.GetTempPath(), pipeName);
+        using var p = new Process();
+        p.StartInfo = new ProcessStartInfo()
         {
-            var path = Path.Combine(Path.GetTempPath(), pipeName);
+            FileName = "mkfifo",
-            using var p = new Process();
+            Arguments = path,
-            p.StartInfo = new ProcessStartInfo()
+            CreateNoWindow = true,
-            {
+            UseShellExecute = false,
-                FileName = "mkfifo",
+            RedirectStandardError = true,
-                Arguments = path,
+            RedirectStandardOutput = true,
-                CreateNoWindow = true,
+        };
-                UseShellExecute = false,
+        p.Start();
-                RedirectStandardError = true,
+        p.WaitForExit();
-                RedirectStandardOutput = true,
+        Thread.Sleep(200);
-            };
+        return new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.Read);
-            p.Start();
-            p.WaitForExit();
-            Thread.Sleep(200);
-            return new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.Read);
-        }
     }
 
     public static async Task<bool> StartPipeMuxAsync(string binary, string[] pipeNames, string outputPath)
@@ -77,7 +75,7 @@ internal static class PipeUtil
 
         if (!string.IsNullOrEmpty(customDest))
         {
-            if (customDest.Trim().StartsWith("-"))
+            if (customDest.Trim().StartsWith('-'))
                 command.Append(customDest);
             else
                 command.Append($" -f mpegts -shortest \"{customDest}\"");