将1078转fmp4_6

src/JT1078.FMp4.Test/JT1078ToFMp4Box_Test.cs

@@ -4,6 +4,7 @@ using JT1078.FMp4.Samples;
 using JT1078.Protocol;
 using JT1078.Protocol.Extensions;
 using JT1078.Protocol.H264;
+using JT1078.Protocol.MessagePack;
 using System;
 using System.Buffers.Binary;
 using System.Collections.Generic;
@@ -166,6 +167,269 @@ namespace JT1078.FMp4.Test
             fileStream.Close();
         }
 
+        [Fact]
+        public void Test2()
+        {
+            var jT1078Package = ParseNALUTest();
+            H264Decoder decoder = new H264Decoder();
+            var nalus = decoder.ParseNALU(jT1078Package);
+            var spsNALU = nalus.FirstOrDefault(n => n.NALUHeader.NalUnitType == 7);
+            //SPS
+            spsNALU.RawData = decoder.DiscardEmulationPreventionBytes(spsNALU.RawData);
+            var ppsNALU = nalus.FirstOrDefault(n => n.NALUHeader.NalUnitType == 8);
+            ppsNALU.RawData = decoder.DiscardEmulationPreventionBytes(ppsNALU.RawData);
+            FMp4MessagePackWriter writer = new FMp4MessagePackWriter(new byte[65535]);
+            //ftyp
+            FileTypeBox fileTypeBox = new FileTypeBox();
+            fileTypeBox.MajorBrand = "isom";
+            fileTypeBox.MinorVersion = "\0\0\u0002\0";
+            fileTypeBox.CompatibleBrands.Add("isom");
+            fileTypeBox.CompatibleBrands.Add("iso6");
+            fileTypeBox.CompatibleBrands.Add("iso2");
+            fileTypeBox.CompatibleBrands.Add("avc1");
+            fileTypeBox.CompatibleBrands.Add("mp41");
+            //moov
+            MovieBox movieBox = new MovieBox();
+            movieBox.MovieHeaderBox = new MovieHeaderBox(0, 0);
+            movieBox.MovieHeaderBox.CreationTime = 0;
+            movieBox.MovieHeaderBox.ModificationTime = 0;
+            movieBox.MovieHeaderBox.Duration = 0;
+            movieBox.MovieHeaderBox.Timescale = 1000;
+            movieBox.MovieHeaderBox.NextTrackID = 2;
+            movieBox.TrackBox = new TrackBox();
+            movieBox.TrackBox.TrackHeaderBox = new TrackHeaderBox(0, 3);
+            movieBox.TrackBox.TrackHeaderBox.CreationTime = 0;
+            movieBox.TrackBox.TrackHeaderBox.ModificationTime = 0;
+            movieBox.TrackBox.TrackHeaderBox.TrackID = 1;
+            movieBox.TrackBox.TrackHeaderBox.Duration = 0;
+            movieBox.TrackBox.TrackHeaderBox.TrackIsAudio = false;
+            movieBox.TrackBox.TrackHeaderBox.Width = 352;
+            movieBox.TrackBox.TrackHeaderBox.Height = 288;
+            movieBox.TrackBox.MediaBox = new MediaBox();
+            movieBox.TrackBox.MediaBox.MediaHeaderBox = new MediaHeaderBox();
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.CreationTime = 0;
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.ModificationTime = 0;
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.Timescale = 1200000;
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.Duration = 0;
+            movieBox.TrackBox.MediaBox.HandlerBox = new HandlerBox();
+            movieBox.TrackBox.MediaBox.HandlerBox.HandlerType = HandlerType.vide;
+            movieBox.TrackBox.MediaBox.HandlerBox.Name = "VideoHandler";
+            movieBox.TrackBox.MediaBox.MediaInformationBox = new MediaInformationBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.VideoMediaHeaderBox = new VideoMediaHeaderBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox = new DataInformationBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox.DataReferenceBox = new DataReferenceBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox.DataReferenceBox.DataEntryBoxes = new List<DataEntryBox>();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox.DataReferenceBox.DataEntryBoxes.Add(new DataEntryUrlBox(1));
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox = new SampleTableBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleDescriptionBox = new SampleDescriptionBox(movieBox.TrackBox.MediaBox.HandlerBox.HandlerType);
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleDescriptionBox.SampleEntries = new List<SampleEntry>();
+            AVC1SampleEntry avc1 = new AVC1SampleEntry();
+            avc1.AVCConfigurationBox = new AVCConfigurationBox();
+            //h264
+            avc1.Width = (ushort)movieBox.TrackBox.TrackHeaderBox.Width;
+            avc1.Height = (ushort)movieBox.TrackBox.TrackHeaderBox.Height;
+            avc1.AVCConfigurationBox.AVCLevelIndication = 20;
+            avc1.AVCConfigurationBox.AVCProfileIndication = 77;
+            avc1.AVCConfigurationBox.PPSs = new List<byte[]>() { ppsNALU.RawData };
+            avc1.AVCConfigurationBox.SPSs = new List<byte[]>() { spsNALU.RawData };
+            avc1.AVCConfigurationBox.ProfileCompatibility = 0;
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleDescriptionBox.SampleEntries.Add(avc1);
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.TimeToSampleBox = new TimeToSampleBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleToChunkBox = new SampleToChunkBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleSizeBox = new SampleSizeBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.ChunkOffsetBox = new ChunkOffsetBox();
+            movieBox.MovieExtendsBox = new MovieExtendsBox();
+            movieBox.MovieExtendsBox.TrackExtendsBoxs = new List<TrackExtendsBox>();
+            TrackExtendsBox trex = new TrackExtendsBox();
+            trex.TrackID = 1;
+            trex.DefaultSampleDescriptionIndex = 1;
+            trex.DefaultSampleDuration = 0;
+            trex.DefaultSampleSize = 0;
+            trex.DefaultSampleFlags = 0;
+            movieBox.MovieExtendsBox.TrackExtendsBoxs.Add(trex);
+            fileTypeBox.ToBuffer(ref writer);
+            movieBox.ToBuffer(ref writer);
+
+            //fragment moof n
+            List<FragmentBox> moofs = new List<FragmentBox>();
+            ulong moofOffset = (ulong)writer.GetCurrentPosition();
+            FragmentBox fragmentBox = new FragmentBox();
+            fragmentBox.MovieFragmentBox = new MovieFragmentBox();
+            fragmentBox.MovieFragmentBox.MovieFragmentHeaderBox = new MovieFragmentHeaderBox();
+            fragmentBox.MovieFragmentBox.MovieFragmentHeaderBox.SequenceNumber = 1;
+            fragmentBox.MovieFragmentBox.TrackFragmentBox = new TrackFragmentBox();
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox = new TrackFragmentHeaderBox(0x39);
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.TrackID = 1;
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.BaseDataOffset = moofOffset;
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.DefaultSampleDuration = 48000;
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.DefaultSampleSize = (uint)jT1078Package.Bodies.Length;
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.DefaultSampleFlags = 0x1010000;
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentBaseMediaDecodeTimeBox = new TrackFragmentBaseMediaDecodeTimeBox();
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentBaseMediaDecodeTimeBox.BaseMediaDecodeTime = 0;
+            //trun
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox = new TrackRunBox(flags: 0x5);
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox.FirstSampleFlags = 0;
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox.TrackRunInfos = new List<TrackRunBox.TrackRunInfo>();
+            fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox.TrackRunInfos.Add(new TrackRunBox.TrackRunInfo());
+            fragmentBox.MediaDataBox = new MediaDataBox();
+            fragmentBox.MediaDataBox.Data = nalus.Select(s => s.RawData).ToList();
+            moofs.Add(fragmentBox);
+            foreach(var moof in moofs)
+            {
+                moof.ToBuffer(ref writer);
+            }
+            //mfra
+            MovieFragmentRandomAccessBox movieFragmentRandomAccessBox = new MovieFragmentRandomAccessBox();
+            //mfra->tfra
+            movieFragmentRandomAccessBox.TrackFragmentRandomAccessBox = new TrackFragmentRandomAccessBox(1);
+            movieFragmentRandomAccessBox.TrackFragmentRandomAccessBox.TrackID = 0x01;
+            movieFragmentRandomAccessBox.TrackFragmentRandomAccessBox.TrackFragmentRandomAccessInfos = new List<TrackFragmentRandomAccessBox.TrackFragmentRandomAccessInfo>();
+            TrackFragmentRandomAccessBox.TrackFragmentRandomAccessInfo trackFragmentRandomAccessInfo1 = new TrackFragmentRandomAccessBox.TrackFragmentRandomAccessInfo();
+            trackFragmentRandomAccessInfo1.Time = 0;
+            trackFragmentRandomAccessInfo1.MoofOffset = moofOffset;
+            trackFragmentRandomAccessInfo1.TrafNumber = 0x01;
+            trackFragmentRandomAccessInfo1.TrunNumber = 0x01;
+            trackFragmentRandomAccessInfo1.SampleNumber = 0x01;
+            movieFragmentRandomAccessBox.TrackFragmentRandomAccessBox.TrackFragmentRandomAccessInfos.Add(trackFragmentRandomAccessInfo1);
+            //mfra->mfro
+            movieFragmentRandomAccessBox.MovieFragmentRandomAccessOffsetBox = new MovieFragmentRandomAccessOffsetBox(0);
+            movieFragmentRandomAccessBox.ToBuffer(ref writer);
+            var buffer = writer.FlushAndGetArray();
+
+            var filepath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "H264", "JT1078_2.mp4");
+            if (File.Exists(filepath))
+            {
+                File.Delete(filepath);
+            }
+            using var fileStream = new FileStream(filepath, FileMode.OpenOrCreate, FileAccess.Write);
+            fileStream.Write(buffer);
+            fileStream.Close();
+        }
+
+        [Fact]
+        public void Test3()
+        {
+            H264Decoder decoder = new H264Decoder();
+            var packages = ParseNALUTests();
+            //10M
+            FMp4MessagePackWriter writer = new FMp4MessagePackWriter(new byte[10 * 1024 * 1024]);
+            var filepath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "H264", "JT1078_3.mp4");
+            if (File.Exists(filepath))
+            {
+                File.Delete(filepath);
+            }
+            using var fileStream = new FileStream(filepath, FileMode.OpenOrCreate, FileAccess.Write);
+            var jT1078Package = packages.FirstOrDefault();
+            var nalus = decoder.ParseNALU(jT1078Package);
+            var spsNALU = nalus.FirstOrDefault(n => n.NALUHeader.NalUnitType == 7);
+            //SPS
+            spsNALU.RawData = decoder.DiscardEmulationPreventionBytes(spsNALU.RawData);
+            var ppsNALU = nalus.FirstOrDefault(n => n.NALUHeader.NalUnitType == 8);
+            ppsNALU.RawData = decoder.DiscardEmulationPreventionBytes(ppsNALU.RawData);
+            ExpGolombReader h264GolombReader = new ExpGolombReader(spsNALU.RawData);
+            var spsInfo = h264GolombReader.ReadSPS();
+            //ftyp
+            FileTypeBox fileTypeBox = new FileTypeBox();
+            fileTypeBox.MajorBrand = "isom";
+            fileTypeBox.MinorVersion = "\0\0\u0002\0";
+            fileTypeBox.CompatibleBrands.Add("isom");
+            fileTypeBox.CompatibleBrands.Add("iso6");
+            fileTypeBox.CompatibleBrands.Add("iso2");
+            fileTypeBox.CompatibleBrands.Add("avc1");
+            fileTypeBox.CompatibleBrands.Add("mp41");
+            //moov
+            MovieBox movieBox = new MovieBox();
+            movieBox.MovieHeaderBox = new MovieHeaderBox(0, 0);
+            movieBox.MovieHeaderBox.CreationTime = 0;
+            movieBox.MovieHeaderBox.ModificationTime = 0;
+            movieBox.MovieHeaderBox.Duration = 0;
+            movieBox.MovieHeaderBox.Timescale = 1000;
+            movieBox.MovieHeaderBox.NextTrackID = 2;
+            movieBox.TrackBox = new TrackBox();
+            movieBox.TrackBox.TrackHeaderBox = new TrackHeaderBox(0, 3);
+            movieBox.TrackBox.TrackHeaderBox.CreationTime = 0;
+            movieBox.TrackBox.TrackHeaderBox.ModificationTime = 0;
+            movieBox.TrackBox.TrackHeaderBox.TrackID = 1;
+            movieBox.TrackBox.TrackHeaderBox.Duration = 0;
+            movieBox.TrackBox.TrackHeaderBox.TrackIsAudio = false;
+            movieBox.TrackBox.TrackHeaderBox.Width = (uint)spsInfo.width;
+            movieBox.TrackBox.TrackHeaderBox.Height = (uint)spsInfo.height;
+            movieBox.TrackBox.MediaBox = new MediaBox();
+            movieBox.TrackBox.MediaBox.MediaHeaderBox = new MediaHeaderBox();
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.CreationTime = 0;
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.ModificationTime = 0;
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.Timescale = 1200000;
+            movieBox.TrackBox.MediaBox.MediaHeaderBox.Duration = 0;
+            movieBox.TrackBox.MediaBox.HandlerBox = new HandlerBox();
+            movieBox.TrackBox.MediaBox.HandlerBox.HandlerType = HandlerType.vide;
+            movieBox.TrackBox.MediaBox.HandlerBox.Name = "VideoHandler";
+            movieBox.TrackBox.MediaBox.MediaInformationBox = new MediaInformationBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.VideoMediaHeaderBox = new VideoMediaHeaderBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox = new DataInformationBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox.DataReferenceBox = new DataReferenceBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox.DataReferenceBox.DataEntryBoxes = new List<DataEntryBox>();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.DataInformationBox.DataReferenceBox.DataEntryBoxes.Add(new DataEntryUrlBox(1));
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox = new SampleTableBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleDescriptionBox = new SampleDescriptionBox(movieBox.TrackBox.MediaBox.HandlerBox.HandlerType);
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleDescriptionBox.SampleEntries = new List<SampleEntry>();
+            AVC1SampleEntry avc1 = new AVC1SampleEntry();
+            avc1.AVCConfigurationBox = new AVCConfigurationBox();
+            //h264
+            avc1.Width = (ushort)movieBox.TrackBox.TrackHeaderBox.Width;
+            avc1.Height = (ushort)movieBox.TrackBox.TrackHeaderBox.Height;
+            avc1.AVCConfigurationBox.AVCLevelIndication = spsInfo.levelIdc;
+            avc1.AVCConfigurationBox.AVCProfileIndication = spsInfo.profileIdc;
+            avc1.AVCConfigurationBox.ProfileCompatibility = (byte)spsInfo.profileCompat;
+            avc1.AVCConfigurationBox.PPSs = new List<byte[]>() { ppsNALU.RawData };
+            avc1.AVCConfigurationBox.SPSs = new List<byte[]>() { spsNALU.RawData };
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleDescriptionBox.SampleEntries.Add(avc1);
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.TimeToSampleBox = new TimeToSampleBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleToChunkBox = new SampleToChunkBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.SampleSizeBox = new SampleSizeBox();
+            movieBox.TrackBox.MediaBox.MediaInformationBox.SampleTableBox.ChunkOffsetBox = new ChunkOffsetBox();
+            movieBox.MovieExtendsBox = new MovieExtendsBox();
+            movieBox.MovieExtendsBox.TrackExtendsBoxs = new List<TrackExtendsBox>();
+            TrackExtendsBox trex = new TrackExtendsBox();
+            trex.TrackID = 1;
+            trex.DefaultSampleDescriptionIndex = 1;
+            trex.DefaultSampleDuration = 0;
+            trex.DefaultSampleSize = 0;
+            trex.DefaultSampleFlags = 0;
+            movieBox.MovieExtendsBox.TrackExtendsBoxs.Add(trex);
+            fileTypeBox.ToBuffer(ref writer);
+            movieBox.ToBuffer(ref writer);
+            //fragment moof n
+            foreach (var package in packages)
+            {
+                ulong moofOffset = (ulong)writer.GetCurrentPosition();
+                var package_nalus = decoder.ParseNALU(package);
+                FragmentBox fragmentBox = new FragmentBox();
+                fragmentBox.MovieFragmentBox = new MovieFragmentBox();
+                fragmentBox.MovieFragmentBox.MovieFragmentHeaderBox = new MovieFragmentHeaderBox();
+                fragmentBox.MovieFragmentBox.MovieFragmentHeaderBox.SequenceNumber = package.SN;
+                fragmentBox.MovieFragmentBox.TrackFragmentBox = new TrackFragmentBox();
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox = new TrackFragmentHeaderBox(0x39);
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.TrackID = 1;
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.BaseDataOffset = moofOffset;
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.DefaultSampleDuration = 48000;
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.DefaultSampleSize = (uint)package.Bodies.Length;
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentHeaderBox.DefaultSampleFlags = 0x1010000;
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentBaseMediaDecodeTimeBox = new TrackFragmentBaseMediaDecodeTimeBox();
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackFragmentBaseMediaDecodeTimeBox.BaseMediaDecodeTime = package.Timestamp;
+                //trun
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox = new TrackRunBox(flags: 0x5);
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox.FirstSampleFlags = 0;
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox.TrackRunInfos = new List<TrackRunBox.TrackRunInfo>();
+                fragmentBox.MovieFragmentBox.TrackFragmentBox.TrackRunBox.TrackRunInfos.Add(new TrackRunBox.TrackRunInfo());
+                fragmentBox.MediaDataBox = new MediaDataBox();
+                fragmentBox.MediaDataBox.Data = package_nalus.Select(s => s.RawData).ToList();
+                fragmentBox.ToBuffer(ref writer);
+            }
+            var buffer = writer.FlushAndGetArray();
+            fileStream.Write(buffer);
+            fileStream.Close();
+        }
+
         [Fact]
         public void tkhd_width_height_test()
         {
@@ -233,5 +497,25 @@ namespace JT1078.FMp4.Test
             }
             return Package;
         }
+
+        public List<JT1078Package> ParseNALUTests()
+        {
+            List<JT1078Package> packages = new List<JT1078Package>();
+            var lines = File.ReadAllLines(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "H264", "jt1078_3.txt"));
+            int mergeBodyLength = 0;
+            foreach (var line in lines)
+            {
+                var data = line.Split(',');
+                var bytes = data[6].ToHexBytes();
+                JT1078Package package = JT1078Serializer.Deserialize(bytes);
+                mergeBodyLength += package.DataBodyLength;
+                var packageMerge = JT1078Serializer.Merge(package);
+                if (packageMerge != null)
+                {
+                    packages.Add(packageMerge);
+                }
+            }
+            return packages;
+        }
     }
 }

src/JT1078.FMp4/Boxs/MovieFragmentBox.cs

@@ -38,6 +38,12 @@ namespace JT1078.FMp4
                 TrackFragmentBox.ToBuffer(ref writer);
             }
             End(ref writer);
+            var trunOffsetPosition = writer.GetTrunOffsetPosition();
+            if (trunOffsetPosition > 0)
+            {
+                writer.WriteInt32Return(writer.GetCurrentPosition() - SizePosition + 8, trunOffsetPosition);
+                writer.ClearTrunOffsetPosition();
+            }
         }
     }
 }

src/JT1078.FMp4/Boxs/MovieFragmentRandomAccessBox.cs

@@ -38,6 +38,12 @@ namespace JT1078.FMp4
                 MovieFragmentRandomAccessOffsetBox.ToBuffer(ref writer);
             }
             End(ref writer);
+            var mfraSizePosition = writer.GetMfraSizePositionn();
+            if (mfraSizePosition > 0)
+            {
+                writer.WriteInt32Return(writer.GetCurrentPosition() - SizePosition, mfraSizePosition);
+                writer.ClearMfraSizePosition();
+            }
         }
     }
 }

src/JT1078.FMp4/Boxs/MovieFragmentRandomAccessOffsetBox.cs

@@ -28,7 +28,17 @@ namespace JT1078.FMp4
         {
             Start(ref writer);
             WriterFullBoxToBuffer(ref writer);
-            writer.WriteUInt32(MfraSize);
+            if (MfraSize > 0)
+            {
+                //人工
+                writer.WriteUInt32(MfraSize);
+            }
+            else
+            {
+                //程序自动计算
+                writer.CreateMfraSizePosition();
+                writer.Skip(4, out _);
+            }
             End(ref writer);
         }
     }

src/JT1078.FMp4/Boxs/TrackRunBox.cs

@@ -52,7 +52,17 @@ namespace JT1078.FMp4
             }
             if((Flags & FMp4Constants.TRUN_FLAG_DATA_OFFSET_PRESENT) > 0)
             {
-                writer.WriteInt32(DataOffset);
+                if (DataOffset > 0)
+                {
+                    //人工
+                    writer.WriteInt32(DataOffset);
+                }
+                else
+                {
+                    //程序自动计算
+                    writer.CreateTrunOffsetPosition();
+                    writer.Skip(4, out _);
+                }
             }
             if ((Flags & FMp4Constants.TRUN_FLAG_FIRST_SAMPLE_FLAGS_PRESENT) > 0)
             {

src/JT1078.FMp4/JT1078.FMp4.xml

@@ -986,7 +986,7 @@
             <summary>
             可选的
             用来表示和该moof配套的mdat中实际数据内容距moof开头有多少byte
-            相当于就是 moof.byteLength + mdat.headerSize
+            相当于就是 moof.byteLength + mdat.headerSize(8)
             </summary>
         </member>
         <member name="P:JT1078.FMp4.TrackRunBox.FirstSampleFlags">
@@ -1250,6 +1250,11 @@
             盒子类型
             </summary>
         </member>
+        <member name="F:JT1078.FMp4.Mp4Box.SizePosition">
+            <summary>
+            
+            </summary>
+        </member>
         <member name="M:JT1078.FMp4.Mp4Box.Start(JT1078.FMp4.MessagePack.FMp4MessagePackWriter@)">
             <summary>
             

src/JT1078.FMp4/MessagePack/FMp4MessagePackWriter.cs

@@ -9,9 +9,16 @@ namespace JT1078.FMp4.MessagePack
     public ref struct FMp4MessagePackWriter
     {
         private FMp4BufferWriter writer;
+
+        private int TrunDataOffsetPosition;
+
+        private int MfraSizePosition;
+
         public FMp4MessagePackWriter(Span<byte> buffer)
         {
             this.writer = new FMp4BufferWriter(buffer);
+            TrunDataOffsetPosition = 0;
+            MfraSizePosition = 0;
         }
         public byte[] FlushAndGetArray()
         {
@@ -90,7 +97,6 @@ namespace JT1078.FMp4.MessagePack
             tmp.CopyTo(writer.Free);
             writer.Advance(count);
         }
-
         public void WriteUInt16Return(ushort value, int position)
         {
             BinaryPrimitives.WriteUInt16BigEndian(writer.Written.Slice(position, 2), value);
@@ -113,6 +119,36 @@ namespace JT1078.FMp4.MessagePack
             return writer.WrittenCount;
         }
 
+        public void CreateTrunOffsetPosition()
+        {
+            TrunDataOffsetPosition = writer.WrittenCount;
+        }
+
+        public int GetTrunOffsetPosition()
+        {
+            return TrunDataOffsetPosition;
+        }
+
+        public void ClearTrunOffsetPosition()
+        {
+            TrunDataOffsetPosition = 0;
+        }
+
+        public void CreateMfraSizePosition()
+        {
+            MfraSizePosition = writer.WrittenCount;
+        }
+
+        public int GetMfraSizePositionn()
+        {
+            return MfraSizePosition;
+        }
+
+        public void ClearMfraSizePosition()
+        {
+            MfraSizePosition = 0;
+        }
+
         /// <summary>
         /// ref
         /// </summary>

src/JT1078.FMp4/Mp4Box.cs

@@ -52,8 +52,10 @@ namespace JT1078.FMp4
         ///// int(8)[16]
         ///// </summary>
         //public string UserType { get; set; }
-
-        private int sizePosition;
+        /// <summary>
+        /// 
+        /// </summary>
+        public int SizePosition;
 
         /// <summary>
         /// 
@@ -61,7 +63,7 @@ namespace JT1078.FMp4
         /// <param name="writer"></param>
         public void Start(ref FMp4MessagePackWriter writer)
         {
-            writer.Skip(FixedSizeLength, out sizePosition);
+            writer.Skip(FixedSizeLength, out SizePosition);
             writer.WriteASCII(BoxType);
         }
         
@@ -71,7 +73,7 @@ namespace JT1078.FMp4
         /// <param name="writer"></param>
         public void End(ref FMp4MessagePackWriter writer)
         {
-            writer.WriteUInt32Return((uint)(writer.GetCurrentPosition() - sizePosition), sizePosition);
+            writer.WriteUInt32Return((uint)(writer.GetCurrentPosition() - SizePosition), SizePosition);
         }
     }
 }