void MP4RtpAtom::WriteHntiType()
{
// since length of string is implicit in size of atom
// we need to handle this specially, and not write the terminating \0
MP4StringProperty* pSdp = (MP4StringProperty*)m_pProperties[1];
pSdp->SetFixedLength(strlen(pSdp->GetValue()));
MP4Atom::Write();
pSdp->SetFixedLength(0);
}
void MP4SdpAtom::Write()
{
// since length of string is implicit in size of atom
// we need to handle this specially, and not write the terminating \0
MP4StringProperty* pSdp = (MP4StringProperty*)m_pProperties[0];
const char* sdpText = pSdp->GetValue();
if (sdpText) {
pSdp->SetFixedLength(strlen(sdpText));
}
MP4Atom::Write();
pSdp->SetFixedLength(0);
}
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;
}