优化`hvcC`生成

This commit is contained in:
nilaoda 2022-11-27 21:59:41 +08:00
parent 999f01e0a0
commit 093794cdd9
1 changed files with 93 additions and 23 deletions

View File

@ -7,6 +7,8 @@ using System.Text.RegularExpressions;
//https://github.com/canalplus/rx-player/blob/48d1f845064cea5c5a3546d2c53b1855c2be149d/src/parsers/manifest/smooth/get_codecs.ts
//https://github.dev/Dash-Industry-Forum/dash.js/blob/2aad3e79079b4de0bcd961ce6b4957103d98a621/src/mss/MssFragmentMoovProcessor.js
//https://github.com/yt-dlp/yt-dlp/blob/3639df54c3298e35b5ae2a96a25bc4d3c38950d0/yt_dlp/downloader/ism.py
//https://github.com/google/ExoPlayer/blob/a9444c880230d2c2c79097e89259ce0b9f80b87d/library/extractor/src/main/java/com/google/android/exoplayer2/video/HevcConfig.java#L38
//https://github.com/sannies/mp4parser/blob/master/isoparser/src/main/java/org/mp4parser/boxes/iso14496/part15/HevcDecoderConfigurationRecord.java
namespace N_m3u8DL_RE.Parser.Mp4
{
public partial class MSSMoovProcessor
@ -92,6 +94,7 @@ namespace N_m3u8DL_RE.Parser.Mp4
}
}
private static string[] HEVC_GENERAL_PROFILE_SPACE_STRINGS = new string[] { "", "A", "B", "C" };
private int SamplingFrequencyIndex(int samplingRate) => samplingRate switch
{
96000 => 0x0,
@ -520,9 +523,9 @@ namespace N_m3u8DL_RE.Parser.Mp4
else if (FourCC == "HVC1" || FourCC == "HEV1")
{
var arr = CodecPrivateData.Split(new[] { StartCode }, StringSplitOptions.RemoveEmptyEntries);
var sps = HexUtil.HexToBytes(arr[0]);
var pps = HexUtil.HexToBytes(arr[1]);
var vps = arr.Length > 2 ? HexUtil.HexToBytes(arr[2]) : null;
var vps = HexUtil.HexToBytes(arr[0]);
var sps = HexUtil.HexToBytes(arr[1]);
var pps = HexUtil.HexToBytes(arr[2]);
//make hvcC
var hvcC = GetHvcC(sps, pps, vps);
writer.Write(hvcC);
@ -582,19 +585,88 @@ namespace N_m3u8DL_RE.Parser.Mp4
return Box("avcC", stream.ToArray()); //AVC Decoder Configuration Record
}
private byte[] GetHvcC(byte[] sps, byte[] pps, byte[]? vps)
private byte[] GetHvcC(byte[] sps, byte[] pps, byte[] vps)
{
var oriSps = new List<byte>(sps);
//https://www.itu.int/rec/dologin.asp?lang=f&id=T-REC-H.265-201504-S!!PDF-E&type=items
//Read generalProfileSpace, generalTierFlag, generalProfileIdc,
//generalProfileCompatibilityFlags, constraintBytes, generalLevelIdc
//from sps
var encList = new List<byte>();
/**
* payload, 00 00 03 0,1,2,3 00 00 XX 03
* 30x0000030x03
* 00 00 03 03 03 03 03 01 => 00 00 01
* 00 00 03 03 03 03 01
*
*
* 42 01 01 01 60 00 00 03 00 90 00 00 03 00 00 03 00 96 a0 01 e0 20 06 61 65 95 9a 49 30 bf fc 0c 7c 0c 81 a8 08 08 08 20 00 00 03 00 20 00 00 03 03 01
* 42 01 01 01 60 00 00 00 90 00 00 00 00 00 96 A0 01 E0 20 06 61 65 95 9A 49 30 BF FC 0C 7C 0C 81 A8 08 08 08 20 00 00 00 20 00 00 01
*/
using (var _reader = new BinaryReader(new MemoryStream(sps)))
{
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)
{
encList.RemoveAt(encList.Count - 1);
}
}
}
sps = encList.ToArray();
using var reader = new BinaryReader2(new MemoryStream(sps));
reader.ReadBytes(2); //Skip 2 bytes unit header
var firstByte = reader.ReadByte();
var maxSubLayersMinus1 = (firstByte & 0xe) >> 1;
var nextByte = reader.ReadByte();
var generalProfileSpace = (nextByte & 0xc0) >> 6;
var generalTierFlag = (nextByte & 0x20) >> 5;
var generalProfileIdc = nextByte & 0x1f;
var generalProfileCompatibilityFlags = reader.ReadUInt32();
var constraintBytes = reader.ReadBytes(6);
var generalLevelIdc = reader.ReadByte();
/*var skipBit = 0;
for (int i = 0; i < maxSubLayersMinus1; i++)
{
skipBit += 2; //sub_layer_profile_present_flag sub_layer_level_present_flag
}
if (maxSubLayersMinus1 > 0)
{
for (int i = maxSubLayersMinus1; i < 8; i++)
{
skipBit += 2; //reserved_zero_2bits
}
}
for (int i = 0; i < maxSubLayersMinus1; i++)
{
skipBit += 2; //sub_layer_profile_present_flag sub_layer_level_present_flag
}*/
//生成编码信息
var codecs = $"hvc1" +
$".{HEVC_GENERAL_PROFILE_SPACE_STRINGS[generalProfileSpace]}{generalProfileIdc}" +
$".{Convert.ToString(generalProfileCompatibilityFlags, 16)}" +
$".{(generalTierFlag == 1 ? 'H' : 'L')}{generalLevelIdc}" +
$".{HexUtil.BytesToHex(constraintBytes.Where(b => b != 0).ToArray())}";
StreamSpec.Codecs = codecs;
///////////////////////
using var stream = new MemoryStream();
using var writer = new BinaryWriter2(stream);
var generalProfileCompatibilityFlags = 0xffffffff;
var generalConstraintIndicatorFlags = 0xffffffffffff;
//var reserved1 = 0xF;
writer.WriteByte(1); //configuration version
writer.WriteByte(0 << 6 | 0 << 5 | 0); //general_profile_space + general_tier_flag + general_profile_idc
writer.WriteByte((byte)((generalProfileSpace << 6) + (generalTierFlag == 1 ? 0x20 : 0) | generalProfileIdc)); //general_profile_space + general_tier_flag + general_profile_idc
writer.WriteUInt(generalProfileCompatibilityFlags); //general_profile_compatibility_flags
writer.WriteUInt(generalConstraintIndicatorFlags >> 16); //general_constraint_indicator_flags
writer.WriteUShort(ushort.MaxValue);
writer.WriteByte(0); //general_level_idc
writer.Write(constraintBytes); //general_constraint_indicator_flags
writer.WriteByte((byte)generalProfileIdc); //general_level_idc
writer.WriteUShort(0xf000); //reserved + min_spatial_segmentation_idc
writer.WriteByte(0xfc); //reserved + parallelismType
writer.WriteByte(0 | 0xfc); //reserved + chromaFormat
@ -602,21 +674,19 @@ namespace N_m3u8DL_RE.Parser.Mp4
writer.WriteByte(0 | 0xf8); //reserved + bitDepthChromaMinus8
writer.WriteUShort(0); //avgFrameRate
writer.WriteByte((byte)(0 << 6 | 0 << 3 | 0 << 2 | (NalUnitLengthField - 1))); //constantFrameRate + numTemporalLayers + temporalIdNested + lengthSizeMinusOne
writer.WriteByte((byte)(vps != null ? 0x03 : 0x02)); //numOfArrays (vps sps pps)
if (vps != null)
{
writer.WriteByte(32); //array_completeness + reserved + NAL_unit_type
writer.WriteUShort(1); //numNalus
writer.WriteUShort(vps.Length);
writer.Write(vps);
}
writer.WriteByte(33);
writer.WriteByte(1); //numNalus
writer.WriteByte(0x03); //numOfArrays (vps sps pps)
sps = oriSps.ToArray();
writer.WriteByte(0x20); //array_completeness + reserved + NAL_unit_type
writer.WriteUShort(1); //numNalus
writer.WriteUShort(vps.Length);
writer.Write(vps);
writer.WriteByte(0x21);
writer.WriteUShort(1); //numNalus
writer.WriteUShort(sps.Length);
writer.Write(sps);
writer.WriteByte(34);
writer.WriteByte(1); //numNalus
writer.WriteByte(0x22);
writer.WriteUShort(1); //numNalus
writer.WriteUShort(pps.Length);
writer.Write(pps);