优化直播字幕时间轴处理

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

@@ -164,6 +164,11 @@ namespace N_m3u8DL_RE.Common.Entity
             }
         }
 
+        private IEnumerable<SubCue> GetCues()
+        {
+            return this.Cues.Where(c => !string.IsNullOrEmpty(c.Payload));
+        }
+
         private static TimeSpan ConvertToTS(string str)
         {
             var ms = Convert.ToInt32(str.Split('.').Last());
@@ -180,7 +185,7 @@ namespace N_m3u8DL_RE.Common.Entity
         public override string ToString()
         {
             StringBuilder sb = new StringBuilder();
-            foreach (var c in this.Cues)
+            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);
                 sb.AppendLine(c.Payload);
@@ -190,9 +195,32 @@ namespace N_m3u8DL_RE.Common.Entity
             return sb.ToString();
         }
 
-        public string ToStringWithHeader()
+        public string ToVtt()
         {
             return "WEBVTT" + Environment.NewLine + Environment.NewLine + ToString();
         }
+
+        public string ToSrt()
+        {
+            StringBuilder sb = new StringBuilder();
+            int index = 1;
+            foreach (var c in GetCues())
+            {
+                sb.AppendLine($"{index++}");
+                sb.AppendLine(c.StartTime.ToString(@"hh\:mm\:ss\,fff") + " --> " + c.EndTime.ToString(@"hh\:mm\:ss\,fff"));
+                sb.AppendLine(c.Payload);
+                sb.AppendLine();
+            }
+            sb.AppendLine();
+
+            var srt = sb.ToString();
+
+            if (string.IsNullOrEmpty(srt.Trim()))
+            {
+                srt = "1\r\n00:00:00,000 --> 00:00:01,000"; //空字幕
+            }
+
+            return srt;
+        }
     }
 }

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

@@ -62,10 +62,10 @@ namespace N_m3u8DL_RE.Parser.Extractor
 
             //选中第一个SmoothStreamingMedia节点
             var ssmElement = xmlDocument.Elements().First(e => e.Name.LocalName == "SmoothStreamingMedia");
-            bool isLive = Convert.ToBoolean(ssmElement.Attribute("IsLive")?.Value ?? "FALSE");
             var timeScaleStr = ssmElement.Attribute("TimeScale")?.Value ?? "10000000";
             var durationStr = ssmElement.Attribute("Duration")?.Value;
             var isLiveStr = ssmElement.Attribute("IsLive")?.Value;
+            bool isLive = Convert.ToBoolean(isLiveStr ?? "FALSE");
 
             var isProtection = false;
             var protectionSystemId = "";
@@ -121,6 +121,7 @@ namespace N_m3u8DL_RE.Parser.Extractor
                     var channels = qualityLevel.Attribute("Channels")?.Value;
 
                     StreamSpec streamSpec = new();
+                    streamSpec.PublishTime = DateTime.Now; //发布时间默认现在
                     streamSpec.Extension = "m4s";
                     streamSpec.OriginalUrl = ParserConfig.OriginalUrl;
                     streamSpec.PeriodId = indexStr;

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

@@ -122,6 +122,11 @@ namespace Mp4SubtitleParser
             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
@@ -163,6 +168,11 @@ namespace Mp4SubtitleParser
             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

src/N_m3u8DL-RE/DownloadManager/SimpleDownloadManager.cs

@@ -360,12 +360,12 @@ namespace N_m3u8DL_RE.DownloadManager
                 FileDic.Clear();
                 var index = 0;
                 var path = Path.Combine(tmpDir, index.ToString(pad) + ".fix.vtt");
-                var subContentFixed = finalVtt.ToStringWithHeader();
+                var subContentFixed = finalVtt.ToVtt();
                 //转换字幕格式
                 if (DownloaderConfig.MyOptions.SubtitleFormat != Enum.SubtitleFormat.VTT)
                 {
                     path = Path.ChangeExtension(path, ".srt");
-                    subContentFixed = OtherUtil.WebVtt2Other(finalVtt, DownloaderConfig.MyOptions.SubtitleFormat);
+                    subContentFixed = finalVtt.ToSrt();
                 }
                 await File.WriteAllTextAsync(path, subContentFixed, Encoding.UTF8);
                 FileDic[keys.First()] = new DownloadResult()
@@ -394,12 +394,12 @@ namespace N_m3u8DL_RE.DownloadManager
                     FileDic.Clear();
                     var index = 0;
                     var path = Path.Combine(tmpDir, index.ToString(pad) + ".fix.vtt");
-                    var subContentFixed = finalVtt.ToStringWithHeader();
+                    var subContentFixed = finalVtt.ToVtt();
                     //转换字幕格式
                     if (DownloaderConfig.MyOptions.SubtitleFormat != Enum.SubtitleFormat.VTT)
                     {
                         path = Path.ChangeExtension(path, ".srt");
-                        subContentFixed = OtherUtil.WebVtt2Other(finalVtt, DownloaderConfig.MyOptions.SubtitleFormat);
+                        subContentFixed = finalVtt.ToSrt();
                     }
                     await File.WriteAllTextAsync(path, subContentFixed, Encoding.UTF8);
                     FileDic[firstKey] = new DownloadResult()
@@ -420,7 +420,7 @@ namespace N_m3u8DL_RE.DownloadManager
                 var keys = FileDic.OrderBy(s => s.Key.Index).Select(s => s.Key);
                 foreach (var seg in keys)
                 {
-                    var vtt = MP4TtmlUtil.ExtractFromTTMLs(new string[] { FileDic[seg]!.ActualFilePath }, 0);
+                    var vtt = MP4TtmlUtil.ExtractFromTTML(FileDic[seg]!.ActualFilePath, 0);
                     //手动计算MPEGTS
                     if (finalVtt.MpegtsTimestamp == 0 && vtt.MpegtsTimestamp == 0)
                     {
@@ -452,12 +452,12 @@ namespace N_m3u8DL_RE.DownloadManager
                 FileDic.Clear();
                 var index = 0;
                 var path = Path.Combine(tmpDir, index.ToString(pad) + ".fix.vtt");
-                var subContentFixed = finalVtt.ToStringWithHeader();
+                var subContentFixed = finalVtt.ToVtt();
                 //转换字幕格式
                 if (DownloaderConfig.MyOptions.SubtitleFormat != Enum.SubtitleFormat.VTT)
                 {
                     path = Path.ChangeExtension(path, ".srt");
-                    subContentFixed = OtherUtil.WebVtt2Other(finalVtt, DownloaderConfig.MyOptions.SubtitleFormat);
+                    subContentFixed = finalVtt.ToSrt();
                 }
                 await File.WriteAllTextAsync(path, subContentFixed, Encoding.UTF8);
                 FileDic[firstKey] = new DownloadResult()
@@ -482,7 +482,7 @@ namespace N_m3u8DL_RE.DownloadManager
                 var keys = FileDic.OrderBy(s => s.Key.Index).Where(v => v.Value!.ActualFilePath.EndsWith(".m4s")).Select(s => s.Key);
                 foreach (var seg in keys)
                 {
-                    var vtt = MP4TtmlUtil.ExtractFromMp4s(new string[] { FileDic[seg]!.ActualFilePath }, 0);
+                    var vtt = MP4TtmlUtil.ExtractFromMp4(FileDic[seg]!.ActualFilePath, 0);
                     //手动计算MPEGTS
                     if (finalVtt.MpegtsTimestamp == 0 && vtt.MpegtsTimestamp == 0)
                     {
@@ -515,12 +515,12 @@ namespace N_m3u8DL_RE.DownloadManager
                 FileDic.Clear();
                 var index = 0;
                 var path = Path.Combine(tmpDir, index.ToString(pad) + ".fix.vtt");
-                var subContentFixed = finalVtt.ToStringWithHeader();
+                var subContentFixed = finalVtt.ToVtt();
                 //转换字幕格式
                 if (DownloaderConfig.MyOptions.SubtitleFormat != Enum.SubtitleFormat.VTT)
                 {
                     path = Path.ChangeExtension(path, ".srt");
-                    subContentFixed = OtherUtil.WebVtt2Other(finalVtt, DownloaderConfig.MyOptions.SubtitleFormat);
+                    subContentFixed = finalVtt.ToSrt();
                 }
                 await File.WriteAllTextAsync(path, subContentFixed, Encoding.UTF8);
                 FileDic[firstKey] = new DownloadResult()

src/N_m3u8DL-RE/DownloadManager/SimpleLiveRecordManager2.cs

@@ -209,6 +209,7 @@ namespace N_m3u8DL_RE.DownloadManager
                 //TryReceiveAll可以稍微缓解一下
                 source.TryReceiveAll(out IList<List<MediaSegment>>? segmentsList);
                 var segments = segmentsList!.SelectMany(s => s);
+                var segmentsDuration = segments.Sum(s => s.Duration);
                 Logger.DebugMarkUp(string.Join(",", segments.Select(sss => GetSegmentName(sss, false, false))));
 
                 //下载init
@@ -355,8 +356,6 @@ namespace N_m3u8DL_RE.DownloadManager
                     }
                 });
 
-                RecordingDurDic[task.Id] += (int)segments.Sum(s => s.Duration);
-
                 //自动修复VTT raw字幕
                 if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
                     && streamSpec.Extension != null && streamSpec.Extension.Contains("vtt"))
@@ -372,15 +371,8 @@ namespace N_m3u8DL_RE.DownloadManager
                         {
                             vtt.MpegtsTimestamp = 90000 * (long)keys.Where(s => s.Index < seg.Index).Sum(s => s.Duration);
                         }
-                        if (firstSub)
+                        if (firstSub) { currentVtt = vtt; firstSub = false; }
-                        {
+                        else currentVtt.AddCuesFromOne(vtt);
-                            currentVtt = vtt;
-                            firstSub = false;
-                        }
-                        else
-                        {
-                            currentVtt.AddCuesFromOne(vtt);
-                        }
                     }
                 }
 
@@ -401,8 +393,8 @@ namespace N_m3u8DL_RE.DownloadManager
                         }
                         else
                         {
-                            var finalVtt = MP4VttUtil.ExtractSub(mp4s, timescale);
+                            var vtt = MP4VttUtil.ExtractSub(mp4s, timescale);
-                            currentVtt.AddCuesFromOne(finalVtt);
+                            currentVtt.AddCuesFromOne(vtt);
                         }
                     }
                 }
@@ -411,21 +403,40 @@ namespace N_m3u8DL_RE.DownloadManager
                 if (DownloaderConfig.MyOptions.AutoSubtitleFix && streamSpec.MediaType == Common.Enum.MediaType.SUBTITLES
                     && streamSpec.Extension != null && streamSpec.Extension.Contains("ttml"))
                 {
-                    var mp4s = FileDic.OrderBy(s => s.Key.Index).Select(s => s.Value).Select(v => v!.ActualFilePath).Where(p => p.EndsWith(".ttml")).ToArray();
+                    var keys = FileDic.OrderBy(s => s.Key.Index).Where(v => v.Value!.ActualFilePath.EndsWith(".m4s")).Select(s => s.Key);
                     if (firstSub)
                     {
                         if (baseTimestamp != 0)
                         {
-                            var total = segments.Sum(s => s.Duration);
+                            var total = segmentsDuration;
                             baseTimestamp -= (long)TimeSpan.FromSeconds(total).TotalMilliseconds;
                         }
-                        currentVtt = MP4TtmlUtil.ExtractFromTTMLs(mp4s, 0, baseTimestamp);
+                        var first = true;
+                        foreach (var seg in keys)
+                        {
+                            var vtt = MP4TtmlUtil.ExtractFromTTML(FileDic[seg]!.ActualFilePath, 0, first ? baseTimestamp : 0);
+                            //手动计算MPEGTS
+                            if (currentVtt.MpegtsTimestamp == 0 && vtt.MpegtsTimestamp == 0)
+                            {
+                                vtt.MpegtsTimestamp = 90000 * (long)keys.Where(s => s.Index < seg.Index).Sum(s => s.Duration);
+                            }
+                            if (first) { currentVtt = vtt; first = false; }
+                            else currentVtt.AddCuesFromOne(vtt);
+                        }
                         firstSub = false;
                     }
                     else
                     {
-                        var finalVtt = MP4TtmlUtil.ExtractFromTTMLs(mp4s, 0, baseTimestamp);
+                        foreach (var seg in keys)
-                        currentVtt.AddCuesFromOne(finalVtt);
+                        {
+                            var vtt = MP4TtmlUtil.ExtractFromTTML(FileDic[seg]!.ActualFilePath, 0);
+                            //手动计算MPEGTS
+                            if (currentVtt.MpegtsTimestamp == 0 && vtt.MpegtsTimestamp == 0)
+                            {
+                                vtt.MpegtsTimestamp = 90000 * (RecordingDurDic[task.Id] + (long)keys.Where(s => s.Index < seg.Index).Sum(s => s.Duration));
+                            }
+                            currentVtt.AddCuesFromOne(vtt);
+                        }
                     }
                 }
 
@@ -438,24 +449,45 @@ namespace N_m3u8DL_RE.DownloadManager
                     //var initFile = FileDic.Values.Where(v => Path.GetFileName(v!.ActualFilePath).StartsWith("_init")).FirstOrDefault();
                     //var iniFileBytes = File.ReadAllBytes(initFile!.ActualFilePath);
                     //var sawTtml = MP4TtmlUtil.CheckInit(iniFileBytes);
-                    var mp4s = FileDic.OrderBy(s => s.Key.Index).Select(s => s.Value).Select(v => v!.ActualFilePath).Where(p => p.EndsWith(".m4s")).ToArray();
+                    var keys = FileDic.OrderBy(s => s.Key.Index).Where(v => v.Value!.ActualFilePath.EndsWith(".m4s")).Select(s => s.Key);
                     if (firstSub)
                     {
                         if (baseTimestamp != 0)
                         {
-                            var total = segments.Sum(s => s.Duration);
+                            var total = segmentsDuration;
                             baseTimestamp -= (long)TimeSpan.FromSeconds(total).TotalMilliseconds;
                         }
-                        currentVtt = MP4TtmlUtil.ExtractFromMp4s(mp4s, 0, baseTimestamp);
+                        var first = true;
+                        foreach (var seg in keys)
+                        {
+                            var vtt = MP4TtmlUtil.ExtractFromMp4(FileDic[seg]!.ActualFilePath, 0, first ? baseTimestamp : 0);
+                            //手动计算MPEGTS
+                            if (currentVtt.MpegtsTimestamp == 0 && vtt.MpegtsTimestamp == 0)
+                            {
+                                vtt.MpegtsTimestamp = 90000 * (long)keys.Where(s => s.Index < seg.Index).Sum(s => s.Duration);
+                            }
+                            if (first) { currentVtt = vtt; first = false; }
+                            else currentVtt.AddCuesFromOne(vtt);
+                        }
                         firstSub = false;
                     }
                     else
                     {
-                        var finalVtt = MP4TtmlUtil.ExtractFromMp4s(mp4s, 0, baseTimestamp);
+                        foreach (var seg in keys)
-                        currentVtt.AddCuesFromOne(finalVtt);
+                        {
+                            var vtt = MP4TtmlUtil.ExtractFromMp4(FileDic[seg]!.ActualFilePath, 0);
+                            //手动计算MPEGTS
+                            if (currentVtt.MpegtsTimestamp == 0 && vtt.MpegtsTimestamp == 0)
+                            {
+                                vtt.MpegtsTimestamp = 90000 * (RecordingDurDic[task.Id] + (long)keys.Where(s => s.Index < seg.Index).Sum(s => s.Duration));
+                            }
+                            currentVtt.AddCuesFromOne(vtt);
+                        }
                     }
                 }
 
+                RecordingDurDic[task.Id] += (int)segmentsDuration;
+
                 /*//写出m3u8
                 if (DownloaderConfig.MyOptions.LiveWriteHLS)
                 {
@@ -538,10 +570,10 @@ namespace N_m3u8DL_RE.DownloadManager
                                 File.Delete(inputFilePath);
                             }
                         }
-                        var subText = currentVtt.ToStringWithHeader();
+                        var subText = currentVtt.ToVtt();
                         if (outputExt == ".srt")
                         {
-                            subText = OtherUtil.WebVtt2Other(currentVtt, Enum.SubtitleFormat.SRT);
+                            subText = currentVtt.ToSrt();
                         }
                         var subBytes = Encoding.UTF8.GetBytes(subText);
                         fileOutputStream.Position = 0;

src/N_m3u8DL-RE/Util/OtherUtil.cs

@@ -27,40 +27,6 @@ namespace N_m3u8DL_RE.Util
             return dic;
         }
 
-        private static string WebVtt2Srt(WebVttSub vtt)
-        {
-            StringBuilder sb = new StringBuilder();
-            int index = 1;
-            foreach (var c in vtt.Cues)
-            {
-                sb.AppendLine($"{index++}");
-                sb.AppendLine(c.StartTime.ToString(@"hh\:mm\:ss\,fff") + " --> " + c.EndTime.ToString(@"hh\:mm\:ss\,fff"));
-                sb.AppendLine(c.Payload);
-                sb.AppendLine();
-            }
-            sb.AppendLine();
-
-            var srt = sb.ToString();
-
-            if (string.IsNullOrEmpty(srt.Trim()))
-            {
-                srt = "1\r\n00:00:00,000 --> 00:00:01,000"; //空字幕
-            }
-
-            return srt;
-        }
-
-        public static string WebVtt2Other(WebVttSub vtt, SubtitleFormat toFormat)
-        {
-            Logger.Debug($"Convert {SubtitleFormat.VTT} ==> {toFormat}");
-            return toFormat switch
-            {
-                SubtitleFormat.VTT => vtt.ToStringWithHeader(),
-                SubtitleFormat.SRT => WebVtt2Srt(vtt),
-                _ => throw new NotSupportedException($"{toFormat} not supported!")
-            };
-        }
-
         private static 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)