void
STSDAtom::ReadDecoderConfig(uint8 **pDecoderConfig, size_t *pDecoderConfigSize,
AudioDescription *pAudioDescription, VideoDescription *pVideoDescription)
{
// Check for a Decoder Config and if it exists copy it back to the caller
// MPEG-4 video/audio use the various decoder config structures to pass
// additional decoder information to the decoder. The extractor sometimes
// needs to decode the data to work out how to properly construct the
// decoder
// First make sure we have a something
if (GetBytesRemaining() > 0) {
// Well something is there so read it as an atom
AtomBase *aAtomBase = GetAtom(theStream);
aAtomBase->ProcessMetaData();
printf("%s [%Ld]\n",aAtomBase->GetAtomName(),aAtomBase->GetAtomSize());
if (dynamic_cast<DecoderConfigAtom *>(aAtomBase)) {
// DecoderConfig atom good
DecoderConfigAtom *aDecoderConfigAtom =
dynamic_cast<DecoderConfigAtom *>(aAtomBase);
aDecoderConfigAtom->OverrideAudioDescription(pAudioDescription);
aDecoderConfigAtom->OverrideVideoDescription(pVideoDescription);
delete aAtomBase;
} else {
// Unknown atom bad
printf("Unknown atom %s\n",aAtomBase->GetAtomName());
delete aAtomBase;
}
}
}
void
CMOVAtom::OnProcessMetaData()
{
BMallocIO *theUncompressedData;
uint8 *outBuffer;
CMVDAtom *aCMVDAtom = NULL;
uint32 compressionID = 0;
uint64 descBytesLeft;
uint32 Size;
descBytesLeft = GetAtomSize();
// Check for Compression Type
while (descBytesLeft > 0) {
AtomBase *aAtomBase = GetAtom(theStream);
aAtomBase->OnProcessMetaData();
if (aAtomBase->GetAtomSize() > 0) {
descBytesLeft = descBytesLeft - aAtomBase->GetAtomSize();
} else {
printf("Invalid Atom found when reading Compressed Headers\n");
descBytesLeft = 0;
}
if (dynamic_cast<DCOMAtom *>(aAtomBase)) {
// DCOM atom
compressionID = dynamic_cast<DCOMAtom *>(aAtomBase)->GetCompressionID();
delete aAtomBase;
} else {
if (dynamic_cast<CMVDAtom *>(aAtomBase)) {
// CMVD atom
aCMVDAtom = dynamic_cast<CMVDAtom *>(aAtomBase);
descBytesLeft = 0;
}
}
}
// Decompress data
if (compressionID == 'zlib') {
Size = aCMVDAtom->GetUncompressedSize();
outBuffer = (uint8 *)(malloc(Size));
printf("Decompressing %ld bytes to %ld bytes\n",aCMVDAtom->GetBufferSize(),Size);
int result = uncompress(outBuffer, &Size, aCMVDAtom->GetCompressedData(), aCMVDAtom->GetBufferSize());
if (result != Z_OK) {
printf("Failed to decompress headers uncompress returned ");
switch (result) {
case Z_MEM_ERROR:
DEBUGGER("Lack of Memory Error\n");
break;
case Z_BUF_ERROR:
DEBUGGER("Lack of Output buffer space Error\n");
break;
case Z_DATA_ERROR:
DEBUGGER("Input Data is corrupt or not a compressed set Error\n");
break;
}
}
// Copy uncompressed data into BMAllocIO
theUncompressedData = new BMallocIO();
theUncompressedData->SetSize(Size);
theUncompressedData->WriteAt(0L,outBuffer,Size);
free(outBuffer);
delete aCMVDAtom;
// reset position on BMAllocIO
theUncompressedData->Seek(SEEK_SET,0L);
// Assign to Stream
theUncompressedStream = theUncompressedData;
// All subsequent reads should use theUncompressedStream
}
}
