这个用例是一项服务，它手动将一系列未压缩的 .wav 媒体片段编码为 .m4s 片段，以便通过 MPEG-DASH 进行广播，使用 ffmpeg 将 .wav 压缩为 .aac 并使用 sannies/mp4parser 将 aac 音频组装成 . m4s 媒体片段。
我创建了这个公共 GitHub 项目来完整地重现这个问题。
例如，这是自定义ChunkFragmentM4sBuilder.java类。
使用 MP4 盒的第一个示例有效，因为我能够生成初始化 MP4 + 系列片段 M4s 文件，然后可以将它们连接起来形成可播放的 MPEG4 流。
注意：此用例要求每个媒体段都从单独生成的源段编码，而不是使用 MP4Box 等工具从连续音频源流式传输。
通过 mp4parser 手动构建媒体片段的尝试总体上仍然失败，因为下面使用的ChunkFragmentM4sBuilder.java编写的片段格式不正确。但我很难理解它们究竟是如何畸形的。
并排比较两个测试日志ChunkFragmentM4sBuilderTest.log.txt 和MP4BoxTest.log.txt对我很有帮助。
通过 Java mp4parser（格式错误）
前一个日志来自ChunkFragmentM4sBuilderTest.java导致串联的测试输出test-java-mp4parser.mp4实际上是空的：
Files.deleteIfExists(Path.of(m4sFilePath));
AACTrackImpl aacTrack=new AACTrackImpl(new FileDataSourceImpl(aacFilePath));
Movie movie=new Movie();
movie.addTrack(aacTrack);
Container mp4file=new ChunkFragmentM4sBuilder(hz,seconds,seqNum,bufferSize).build(movie);
FileChannel fc=new FileOutputStream(m4sFilePath).getChannel();
mp4file.writeContainer(fc);
fc.close();
连接框：
FileTypeBox[majorBrand=iso5;minorVersion=512;compatibleBrand=iso6;compatibleBrand=mp41]
MovieBox[MovieHeaderBox[creationTime=Thu Dec 31 16:00:00 PST 1903;modificationTime=Thu Dec 31 16:00:00 PST 1903;timescale=1000;duration=0;rate=1.0;volume=1.0;matrix=Rotate 0°;nextTrackId=2];TrackBox[TrackHeaderBox[creationTime=Thu Dec 31 16:00:00 PST 1903;modificationTime=Thu Dec 31 16:00:00 PST 1903;trackId=1;duration=0;layer=0;alternateGroup=1;volume=1.0;matrix=Rotate 0°;width=0.0;height=0.0];EditBox[EditListBox{entries=[Entry{segmentDuration=0, mediaTime=1024, mediaRate=1.0}]}];MediaBox[MediaHeaderBox[creationTime=Thu Dec 31 16:00:00 PST 1903;modificationTime=Thu Dec 31 16:00:00 PST 1903;timescale=48000;duration=0;language=und];HandlerBox[handlerType=soun;name=SoundHandler];MediaInformationBox[SoundMediaHeaderBox[balance=0.0];DataInformationBox[DataReferenceBox[DataEntryUrlBox[]]];SampleTableBox[SampleDescriptionBox[AudioSampleEntry{bytesPerSample=0, bytesPerFrame=0, bytesPerPacket=0, samplesPerPacket=0, packetSize=0, compressionId=0, soundVersion=0, sampleRate=48000, sampleSize=16, channelCount=2, boxes=[org.mp4parser.boxes.iso14496.part14.ESDescriptorBox@bed094d2]}];TimeToSampleBox[entryCount=0];SampleToChunkBox[entryCount=0];SampleSizeBox[sampleSize=0;sampleCount=0];StaticChunkOffsetBox[entryCount=0]]]]];MovieExtendsBox[org.mp4parser.boxes.iso14496.part12.TrackExtendsBox@11e7301d];UserDataBox[MetaBox[HandlerBox[handlerType=mdir;name=];AppleItemListBox[org.mp4parser.boxes.apple.AppleEncoderBox@691fba4]]]]
SegmentTypeBox[majorBrand=msdh;minorVersion=0;compatibleBrand=msdh;compatibleBrand=msix]
SegmentIndexBox{entries=[Entry{referenceType=0, referencedSize=160944, subsegmentDuration=480000, startsWithSap=1, sapType=0, sapDeltaTime=0}], referenceId=1, timeScale=48000, earliestPresentationTime=0, firstOffset=0, reserved=0}
MovieFragmentBox[MovieFragmentHeaderBox{sequenceNumber=151304042};TrackFragmentBox[TrackFragmentHeaderBox{trackId=1, baseDataOffset=-1, sampleDescriptionIndex=0, defaultSampleDuration=-1, defaultSampleSize=-1, defaultSampleFlags=null, durationIsEmpty=true, defaultBaseIsMoof=true};TrackFragmentBaseMediaDecodeTimeBox{baseMediaDecodeTime=0};TrackRunBox{sampleCount=470, dataOffset=-1, dataOffsetPresent=false, sampleSizePresent=true, sampleDurationPresent=true, sampleFlagsPresentPresent=false, sampleCompositionTimeOffsetPresent=false, firstSampleFlags=null}]]
org.mp4parser.boxes.iso14496.part12.MediaDataBox@3969adb0
通过 MP4Box（好的）
后一个日志来自MP4BoxTest.java，这导致连接的测试输出 test-mp4box.mp4可以。
但是请注意，此方法对于最终用例是不可接受的，因为此 hack 方法输出的块中存在缺陷。
MP4Box \
-profile live \
-add aacFilePath \
-dash 10000 \
-frag 10000 \
-idx ${NUM} \
-moof-sn ${NUM} \
-out test5.mpd \
-segment-name test5-128k- \
-segment-ext m4s \
-single-traf \
-subsegs-per-sidx 0 \
-daisy-chain \
-single-segment \
/tmp
连接框：
FileTypeBox[majorBrand=iso5;minorVersion=512;compatibleBrand=iso6;compatibleBrand=mp41]
MovieBox[MovieHeaderBox[creationTime=Thu Dec 31 16:00:00 PST 1903;modificationTime=Thu Dec 31 16:00:00 PST 1903;timescale=1000;duration=0;rate=1.0;volume=1.0;matrix=Rotate 0°;nextTrackId=2];TrackBox[TrackHeaderBox[creationTime=Thu Dec 31 16:00:00 PST 1903;modificationTime=Thu Dec 31 16:00:00 PST 1903;trackId=1;duration=0;layer=0;alternateGroup=1;volume=1.0;matrix=Rotate 0°;width=0.0;height=0.0];EditBox[EditListBox{entries=[Entry{segmentDuration=0, mediaTime=1024, mediaRate=1.0}]}];MediaBox[MediaHeaderBox[creationTime=Thu Dec 31 16:00:00 PST 1903;modificationTime=Thu Dec 31 16:00:00 PST 1903;timescale=48000;duration=0;language=und];HandlerBox[handlerType=soun;name=SoundHandler];MediaInformationBox[SoundMediaHeaderBox[balance=0.0];DataInformationBox[DataReferenceBox[DataEntryUrlBox[]]];SampleTableBox[SampleDescriptionBox[AudioSampleEntry{bytesPerSample=0, bytesPerFrame=0, bytesPerPacket=0, samplesPerPacket=0, packetSize=0, compressionId=0, soundVersion=0, sampleRate=48000, sampleSize=16, channelCount=2, boxes=[org.mp4parser.boxes.iso14496.part14.ESDescriptorBox@bed094d2]}];TimeToSampleBox[entryCount=0];SampleToChunkBox[entryCount=0];SampleSizeBox[sampleSize=0;sampleCount=0];StaticChunkOffsetBox[entryCount=0]]]]];MovieExtendsBox[org.mp4parser.boxes.iso14496.part12.TrackExtendsBox@7ce1e496];UserDataBox[MetaBox[HandlerBox[handlerType=mdir;name=];AppleItemListBox[org.mp4parser.boxes.apple.AppleEncoderBox@51da5351]]]]
SegmentTypeBox[majorBrand=msdh;minorVersion=0;compatibleBrand=msdh;compatibleBrand=msix]
SegmentIndexBox{entries=[Entry{referenceType=0, referencedSize=162267, subsegmentDuration=479232, startsWithSap=1, sapType=1, sapDeltaTime=0}], referenceId=1, timeScale=48000, earliestPresentationTime=0, firstOffset=0, reserved=0}
MovieFragmentBox[MovieFragmentHeaderBox{sequenceNumber=151304042};TrackFragmentBox[TrackFragmentHeaderBox{trackId=1, baseDataOffset=-1, sampleDescriptionIndex=0, defaultSampleDuration=-1, defaultSampleSize=-1, defaultSampleFlags=null, durationIsEmpty=false, defaultBaseIsMoof=true};TrackFragmentBaseMediaDecodeTimeBox{baseMediaDecodeTime=0};TrackRunBox{sampleCount=468, dataOffset=1964, dataOffsetPresent=true, sampleSizePresent=true, sampleDurationPresent=false, sampleFlagsPresentPresent=false, sampleCompositionTimeOffsetPresent=false, firstSampleFlags=null}]]
org.mp4parser.boxes.iso14496.part12.MediaDataBox@640d3ba5