private void RestoreTables()
{
uint lastRealChunkNumber = STCO.EntryCount + 1;
ChunksToSamples = new ChunkToSample[STCO.EntryCount];
var items = STSC.Items;
for (int i = items.Length - 1; i >= 0; i--)
{
var item = STSC.Items[i];
uint begRealChunkNumer = item.FirstChunk;
for (uint chki = begRealChunkNumer - 1; chki < lastRealChunkNumber - 1; ++chki)
{
ChunksToSamples[chki] = new ChunkToSample()
{
SamplesCount = item.SamplesPerChunk,
SampleDescriptionIndex = item.SampleDescriptionIndex
};
}
lastRealChunkNumber = begRealChunkNumer;
}
UInt32 sampleIndex = 0;
SampleEntries = new SampleEntry[STSZ.SampleCount];
for (uint i = 0; i < ChunksToSamples.Length; i++)
{
ChunksToSamples[i].FirstSampleIndex = sampleIndex;
UInt32 indexInChunk = 0;
for (uint sami = 0; sami != ChunksToSamples[i].SamplesCount; sami++)
{
SampleEntries[sampleIndex] = new SampleEntry()
{
ChunkIndex = i,
IndexInChunk = indexInChunk,
};
sampleIndex++;
indexInChunk++;
}
}
}
static SampleEntry[] parseSampleTable(Mp4Reader reader)
{
Debug.Assert(reader.currentBox == eBoxType.stsd);
Span <byte> span = stackalloc byte[8];
reader.read(span);
int entryCount = BitConverter.ToInt32(span.Slice(4)).endian();
SampleEntry[] result = new SampleEntry[entryCount];
for (int i = 0; i < entryCount; i++)
{
reader.read(span);
int length = BitConverter.ToInt32(span).endian();
uint code = BitConverter.ToUInt32(span.Slice(4));
switch (code)
{
case (uint)eFileType.avc1:
result[i] = new AVC1SampleEntry(reader, length - 8);
break;
case (uint)eAudioBoxType.mp4a:
result[i] = new MP4AudioSampleEntry(reader, length - 8);
break;
case (uint)eAudioBoxType.ac3:
result[i] = new Ac3AudioSampleEntry(reader, length - 8);
break;
default:
throw new NotImplementedException("The sample format is not currently supported");
}
}
return(result);
}