/*----------------------------------------------------------------------
| AP4_MarlinIpmpParser:Parse
+---------------------------------------------------------------------*/
AP4_Result
AP4_MarlinIpmpParser::Parse(AP4_AtomParent& top_level,
AP4_ByteStream& stream,
AP4_List<SinfEntry>& sinf_entries,
bool remove_od_data)
{
// check the file type
AP4_FtypAtom* ftyp = AP4_DYNAMIC_CAST(AP4_FtypAtom, top_level.GetChild(AP4_ATOM_TYPE_FTYP));
if (ftyp == NULL ||
(ftyp->GetMajorBrand() != AP4_MARLIN_BRAND_MGSV && !ftyp->HasCompatibleBrand(AP4_MARLIN_BRAND_MGSV))) {
return AP4_ERROR_INVALID_FORMAT;
}
// check the initial object descriptor and get the OD Track ID
AP4_IodsAtom* iods = AP4_DYNAMIC_CAST(AP4_IodsAtom, top_level.FindChild("moov/iods"));
AP4_UI32 od_track_id = 0;
if (iods == NULL) return AP4_ERROR_INVALID_FORMAT;
const AP4_ObjectDescriptor* od = iods->GetObjectDescriptor();
if (od == NULL) return AP4_ERROR_INVALID_FORMAT;
AP4_EsIdIncDescriptor* es_id_inc = AP4_DYNAMIC_CAST(AP4_EsIdIncDescriptor, od->FindSubDescriptor(AP4_DESCRIPTOR_TAG_ES_ID_INC));
if (es_id_inc == NULL) return AP4_ERROR_INVALID_FORMAT;
od_track_id = es_id_inc->GetTrackId();
// find the track pointed to by the descriptor
AP4_MoovAtom* moov = AP4_DYNAMIC_CAST(AP4_MoovAtom, top_level.GetChild(AP4_ATOM_TYPE_MOOV));
if (moov == NULL) return AP4_ERROR_INVALID_FORMAT;
AP4_TrakAtom* od_trak = NULL;
for (AP4_List<AP4_TrakAtom>::Item* trak_item = moov->GetTrakAtoms().FirstItem();
trak_item;
trak_item = trak_item->GetNext()) {
AP4_TrakAtom* trak = trak_item->GetData();
if (trak) {
if (trak->GetId() == od_track_id) {
od_trak = trak;
} else {
sinf_entries.Add(new SinfEntry(trak->GetId(), NULL));
}
}
}
// check that we have found the OD track
if (od_trak == NULL) return AP4_ERROR_INVALID_FORMAT;
// look for the 'mpod' trak references
AP4_TrefTypeAtom* track_references;
track_references = AP4_DYNAMIC_CAST(AP4_TrefTypeAtom, od_trak->FindChild("tref/mpod"));
if (track_references == NULL) return AP4_ERROR_INVALID_FORMAT;
// create an AP4_Track object from the trak atom and check that it has samples
AP4_Track* od_track = new AP4_Track(*od_trak, stream, 0);
if (od_track->GetSampleCount() < 1) {
delete od_track;
return AP4_ERROR_INVALID_FORMAT;
}
// get the first sample (in this version, we only look at a single OD command)
AP4_Sample od_sample;
AP4_Result result = od_track->GetSample(0, od_sample);
if (AP4_FAILED(result)) {
delete od_track;
return AP4_ERROR_INVALID_FORMAT;
}
// adapt the sample data into a byte stream for parsing
AP4_DataBuffer sample_data;
od_sample.ReadData(sample_data);
AP4_MemoryByteStream* sample_stream = new AP4_MemoryByteStream(sample_data);
// look for one ObjectDescriptorUpdate command and
// one IPMP_DescriptorUpdate command
AP4_DescriptorUpdateCommand* od_update = NULL;
AP4_DescriptorUpdateCommand* ipmp_update = NULL;
do {
AP4_Command* command = NULL;
result = AP4_CommandFactory::CreateCommandFromStream(*sample_stream, command);
if (AP4_SUCCEEDED(result)) {
// found a command in the sample, check the type
switch (command->GetTag()) {
case AP4_COMMAND_TAG_OBJECT_DESCRIPTOR_UPDATE:
if (od_update == NULL) {
od_update = AP4_DYNAMIC_CAST(AP4_DescriptorUpdateCommand, command);
}
break;
case AP4_COMMAND_TAG_IPMP_DESCRIPTOR_UPDATE:
if (ipmp_update == NULL) {
ipmp_update = AP4_DYNAMIC_CAST(AP4_DescriptorUpdateCommand, command);
}
break;
default:
break;
}
}
} while (AP4_SUCCEEDED(result));
sample_stream->Release();
sample_stream = NULL;
// check that we have what we need
if (od_update == NULL || ipmp_update == NULL) {
delete od_track;
return AP4_ERROR_INVALID_FORMAT;
}
// process all the object descriptors in the od update
for (AP4_List<AP4_Descriptor>::Item* od_item = od_update->GetDescriptors().FirstItem();
od_item;
od_item = od_item->GetNext()) {
od = AP4_DYNAMIC_CAST(AP4_ObjectDescriptor, od_item->GetData());
if (od == NULL) continue;
// find which track this od references
AP4_EsIdRefDescriptor* es_id_ref;
es_id_ref = AP4_DYNAMIC_CAST(AP4_EsIdRefDescriptor, od->FindSubDescriptor(AP4_DESCRIPTOR_TAG_ES_ID_REF));
if (es_id_ref == NULL ||
es_id_ref->GetRefIndex() > track_references->GetTrackIds().ItemCount() ||
es_id_ref->GetRefIndex() == 0) {
continue;
}
AP4_UI32 track_id = track_references->GetTrackIds()[es_id_ref->GetRefIndex()-1];
SinfEntry* sinf_entry = NULL;
for (AP4_List<SinfEntry>::Item* sinf_entry_item = sinf_entries.FirstItem();
sinf_entry_item;
sinf_entry_item = sinf_entry_item->GetNext()) {
sinf_entry = sinf_entry_item->GetData();
if (sinf_entry->m_TrackId == track_id) {
break; // match
} else {
sinf_entry = NULL; // no match
}
}
if (sinf_entry == NULL) continue; // no matching entry
if (sinf_entry->m_Sinf != NULL) continue; // entry already populated
// see what ipmp descriptor this od points to
AP4_IpmpDescriptorPointer* ipmpd_pointer;
ipmpd_pointer = AP4_DYNAMIC_CAST(AP4_IpmpDescriptorPointer, od->FindSubDescriptor(AP4_DESCRIPTOR_TAG_IPMP_DESCRIPTOR_POINTER));
if (ipmpd_pointer == NULL) continue; // no pointer
// find the ipmp descriptor referenced by the pointer
AP4_IpmpDescriptor* ipmpd = NULL;
for (AP4_List<AP4_Descriptor>::Item* ipmpd_item = ipmp_update->GetDescriptors().FirstItem();
ipmpd_item;
ipmpd_item = ipmpd_item->GetNext()) {
// check that this descriptor is of the right type
ipmpd = AP4_DYNAMIC_CAST(AP4_IpmpDescriptor, ipmpd_item->GetData());
if (ipmpd == NULL || ipmpd->GetIpmpsType() != AP4_MARLIN_IPMPS_TYPE_MGSV) continue;
// check the descriptor id
if (ipmpd->GetDescriptorId() == ipmpd_pointer->GetDescriptorId()) {
break; // match
} else {
ipmpd = NULL; // no match
}
}
if (ipmpd == NULL) continue; // no matching entry
// parse the ipmp data into one or more 'sinf' atoms, and keep the one with the
// right type
AP4_MemoryByteStream* data = new AP4_MemoryByteStream(ipmpd->GetData().GetData(),
ipmpd->GetData().GetDataSize());
AP4_LargeSize bytes_available = ipmpd->GetData().GetDataSize();
do {
AP4_Atom* atom = NULL;
// setup the factory with a context so we can instantiate a 'schm'
// atom with a slightly different format than the standard 'schm'
AP4_AtomFactory* factory = &AP4_MarlinIpmpAtomFactory::Instance;
factory->PushContext(AP4_ATOM_TYPE('m','r','l','n'));
// parse the next atom in the stream
result = factory->CreateAtomFromStream(*data, bytes_available, atom);
factory->PopContext();
if (AP4_FAILED(result) || atom == NULL) break;
// check that what we have parsed is indeed an 'sinf' of the right type
if (atom->GetType() == AP4_ATOM_TYPE_SINF) {
AP4_ContainerAtom* sinf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, atom);
AP4_SchmAtom* schm = AP4_DYNAMIC_CAST(AP4_SchmAtom, sinf->FindChild("schm"));
if ((schm->GetSchemeType() == AP4_PROTECTION_SCHEME_TYPE_MARLIN_ACBC &&
schm->GetSchemeVersion() == 0x0100) ||
(schm->GetSchemeType() == AP4_PROTECTION_SCHEME_TYPE_MARLIN_ACGK &&
schm->GetSchemeVersion() == 0x0100)) {
// store the sinf in the entry for that track
sinf_entry->m_Sinf = sinf;
break;
}
}
delete atom;
} while (AP4_SUCCEEDED(result));
data->Release();
}
// get rid of entries that have no SINF
for (AP4_List<SinfEntry>::Item* sinf_entry_item = sinf_entries.FirstItem();
sinf_entry_item;
sinf_entry_item = sinf_entry_item->GetNext()) {
SinfEntry* sinf_entry = sinf_entry_item->GetData();
if (sinf_entry->m_Sinf == NULL) {
sinf_entries.Remove(sinf_entry);
sinf_entry_item = sinf_entries.FirstItem();
continue;
}
}
// remove the iods atom and the OD track if required
if (remove_od_data) {
od_trak->Detach();
delete od_trak;
iods->Detach();
delete iods;
}
// cleanup
delete od_track;
return AP4_SUCCESS;
}
