C++ (Cpp) MP4Atom::GetFlags Examples

Example #1

File: mp4track.cpp Project: TravisKraatz/cinelerra

FILE* MP4Track::GetSampleFile(MP4SampleId sampleId)
{
	u_int32_t stscIndex =
		GetSampleStscIndex(sampleId);

	u_int32_t stsdIndex = 
		m_pStscSampleDescrIndexProperty->GetValue(stscIndex);

	// check if the answer will be the same as last time
	if (m_lastStsdIndex && stsdIndex == m_lastStsdIndex) {
		return m_lastSampleFile;
	}

	MP4Atom* pStsdAtom = 
		m_pTrakAtom->FindAtom("trak.mdia.minf.stbl.stsd");
	ASSERT(pStsdAtom);

	MP4Atom* pStsdEntryAtom = 
		pStsdAtom->GetChildAtom(stsdIndex - 1);
	ASSERT(pStsdEntryAtom);

	MP4Integer16Property* pDrefIndexProperty = NULL;
	pStsdEntryAtom->FindProperty(
		"*.dataReferenceIndex",
		(MP4Property**)&pDrefIndexProperty);
	
	if (pDrefIndexProperty == NULL) {
		throw new MP4Error("invalid stsd entry", "GetSampleFile");
	}

	u_int32_t drefIndex =
		pDrefIndexProperty->GetValue();

	MP4Atom* pDrefAtom =
		m_pTrakAtom->FindAtom("trak.mdia.minf.dinf.dref");
	ASSERT(pDrefAtom);

	MP4Atom* pUrlAtom =
		pDrefAtom->GetChildAtom(drefIndex - 1);
	ASSERT(pUrlAtom);

	FILE* pFile;

	if (pUrlAtom->GetFlags() & 1) {
		pFile = NULL;	// self-contained
	} else {
#ifndef USE_FILE_CALLBACKS
		MP4StringProperty* pLocationProperty = NULL;
		pUrlAtom->FindProperty(
			"*.location", 
			(MP4Property**)&pLocationProperty);
		ASSERT(pLocationProperty);

		const char* url = pLocationProperty->GetValue();

		VERBOSE_READ_SAMPLE(m_pFile->GetVerbosity(),
			printf("dref url = %s\n", url));

		pFile = (FILE*)-1;

		// attempt to open url if it's a file url 
		// currently this is the only thing we understand
		if (!strncmp(url, "file:", 5)) {
			const char* fileName = url + 5;
			if (!strncmp(fileName, "//", 2)) {
				fileName = strchr(fileName + 2, '/');
			}
			if (fileName) {
				pFile = fopen(fileName, "rb");
				if (!pFile) {
					pFile = (FILE*)-1;
				}
			}
		} 
#else
        throw new MP4Error(errno, "Function not supported when using callbacks", "GetSampleFile");
#endif
	}

	if (m_lastSampleFile) {
#ifndef USE_FILE_CALLBACKS
		fclose(m_lastSampleFile);
#else
        throw new MP4Error(errno, "Function not supported when using callbacks", "GetSampleFile");
#endif
	}

	// cache the answer
	m_lastStsdIndex = stsdIndex;
	m_lastSampleFile = pFile;

	return pFile;
}