/*----------------------------------------------------------------------
|   AP4_FragmentSampleTable::AP4_FragmentSampleTable
+---------------------------------------------------------------------*/
AP4_FragmentSampleTable::AP4_FragmentSampleTable(AP4_ContainerAtom* traf,
        AP4_TrexAtom*      trex,
        AP4_Cardinal       internal_track_id,
        AP4_ByteStream*    sample_stream,
        AP4_Position       moof_offset,
        AP4_Position       mdat_payload_offset,
        AP4_UI64           dts_origin)
    :m_InternalTrackId(internal_track_id)
{
    AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD));
    if (tfhd == NULL) return;

    // count all the samples and reserve space for them
    unsigned int sample_count = 0;
    for (AP4_List<AP4_Atom>::Item* item = traf->GetChildren().FirstItem();
            item;
            item = item->GetNext()) {
        AP4_Atom* atom = item->GetData();
        if (atom->GetType() == AP4_ATOM_TYPE_TRUN) {
            AP4_TrunAtom* trun = AP4_DYNAMIC_CAST(AP4_TrunAtom, atom);
            if (trun) sample_count += trun->GetEntries().ItemCount();
        }
    }
    m_Samples.EnsureCapacity(sample_count);

    // check if we have a timecode base
    AP4_TfdtAtom* tfdt = AP4_DYNAMIC_CAST(AP4_TfdtAtom, traf->GetChild(AP4_ATOM_TYPE_TFDT));
    if (tfdt) {
        dts_origin = tfdt->GetBaseMediaDecodeTime();
    }

    // process all the trun atoms
    for (AP4_List<AP4_Atom>::Item* item = traf->GetChildren().FirstItem();
            item;
            item = item->GetNext()) {
        AP4_Atom* atom = item->GetData();
        if (atom->GetType() == AP4_ATOM_TYPE_TRUN) {
            AP4_TrunAtom* trun = AP4_DYNAMIC_CAST(AP4_TrunAtom, atom);
            if (trun) {
                AP4_Result result = AddTrun(trun,
                                            tfhd,
                                            trex,
                                            sample_stream,
                                            moof_offset,
                                            mdat_payload_offset,
                                            dts_origin);
                if (AP4_FAILED(result)) return;
            }
        }
    }
}
Exemplo n.º 2
0
/*----------------------------------------------------------------------
|   AutoDetectAudioFragmentDuration
+---------------------------------------------------------------------*/
static unsigned int 
AutoDetectAudioFragmentDuration(AP4_ByteStream& stream, TrackCursor* cursor)
{
    // remember where we are in the stream
    AP4_Position where = 0;
    stream.Tell(where);
    AP4_LargeSize stream_size = 0;
    stream.GetSize(stream_size);
    AP4_LargeSize bytes_available = stream_size-where;
    
    AP4_UI64  fragment_count = 0;
    AP4_UI32  last_fragment_size = 0;
    AP4_Atom* atom = NULL;
    while (AP4_SUCCEEDED(AP4_DefaultAtomFactory::Instance.CreateAtomFromStream(stream, bytes_available, atom))) {
        if (atom && atom->GetType() == AP4_ATOM_TYPE_MOOF) {
            AP4_ContainerAtom* moof = AP4_DYNAMIC_CAST(AP4_ContainerAtom, atom);
            AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, moof->FindChild("traf/tfhd"));
            if (tfhd && tfhd->GetTrackId() == cursor->m_Track->GetId()) {
                ++fragment_count;
                AP4_TrunAtom* trun = AP4_DYNAMIC_CAST(AP4_TrunAtom, moof->FindChild("traf/trun"));
                if (trun) {
                    last_fragment_size = trun->GetEntries().ItemCount();
                }
            }
        }
        delete atom;
        atom = NULL;
    }
    
    // restore the stream to its original position
    stream.Seek(where);
    
    // decide if we can infer an fragment size
    if (fragment_count == 0 || cursor->m_Samples->GetSampleCount() == 0) {
        return 0;
    }
    // don't count the last fragment if we have more than one
    if (fragment_count > 1 && last_fragment_size) {
        --fragment_count;
    }
    if (fragment_count <= 1 || cursor->m_Samples->GetSampleCount() < last_fragment_size) {
        last_fragment_size = 0;
    }
    AP4_Sample sample;
    AP4_UI64 total_duration = 0;
    for (unsigned int i=0; i<cursor->m_Samples->GetSampleCount()-last_fragment_size; i++) {
        cursor->m_Samples->GetSample(i, sample);
        total_duration += sample.GetDuration();
    }
    return (unsigned int)AP4_ConvertTime(total_duration/fragment_count, cursor->m_Track->GetMediaTimeScale(), 1000);
}
Exemplo n.º 3
0
/*----------------------------------------------------------------------
|   Fragment
+---------------------------------------------------------------------*/
static void
Fragment(AP4_File&                input_file,
         AP4_ByteStream&          output_stream,
         AP4_Array<TrackCursor*>& cursors,
         unsigned int             fragment_duration,
         AP4_UI32                 timescale,
         AP4_UI32                 track_id,
         bool                     create_segment_index)
{
    AP4_List<FragmentInfo> fragments;
    TrackCursor*           index_cursor = NULL;
    AP4_Result             result;
    
    AP4_Movie* input_movie = input_file.GetMovie();
    if (input_movie == NULL) {
        fprintf(stderr, "ERROR: no moov found in the input file\n");
        return;
    }

    // create the output file object
    AP4_Movie* output_movie = new AP4_Movie(1000);
    
    // create an mvex container
    AP4_ContainerAtom* mvex = new AP4_ContainerAtom(AP4_ATOM_TYPE_MVEX);
    AP4_MehdAtom*      mehd = new AP4_MehdAtom(0);
    mvex->AddChild(mehd);
    
    // add an output track for each track in the input file
    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
        AP4_Track* track = cursors[i]->m_Track;
        
        // skip non matching tracks if we have a selector
        if (track_id && track->GetId() != track_id) {
            continue;
        }
        
        result = cursors[i]->Init();
        if (AP4_FAILED(result)) {
            fprintf(stderr, "ERROR: failed to init sample cursor (%d), skipping track %d\n", result, track->GetId());
            return;
        }

        // create a sample table (with no samples) to hold the sample description
        AP4_SyntheticSampleTable* sample_table = new AP4_SyntheticSampleTable();
        for (unsigned int j=0; j<track->GetSampleDescriptionCount(); j++) {
            AP4_SampleDescription* sample_description = track->GetSampleDescription(j);
            sample_table->AddSampleDescription(sample_description, false);
        }
        
        // create the track
        AP4_Track* output_track = new AP4_Track(sample_table,
                                                track->GetId(),
                                                timescale?timescale:1000,
                                                AP4_ConvertTime(track->GetDuration(),
                                                                input_movie->GetTimeScale(),
                                                                timescale?timescale:1000),
                                                timescale?timescale:track->GetMediaTimeScale(),
                                                0,//track->GetMediaDuration(),
                                                track);
        output_movie->AddTrack(output_track);
        
        // add a trex entry to the mvex container
        AP4_TrexAtom* trex = new AP4_TrexAtom(track->GetId(),
                                              1,
                                              0,
                                              0,
                                              0);
        mvex->AddChild(trex);
    }
    
    // select the anchor cursor
    TrackCursor* anchor_cursor = NULL;
    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
        if (cursors[i]->m_Track->GetId() == track_id) {
            anchor_cursor = cursors[i];
        }
    }
    if (anchor_cursor == NULL) {
        for (unsigned int i=0; i<cursors.ItemCount(); i++) {
            // use this as the anchor track if it is the first video track
            if (cursors[i]->m_Track->GetType() == AP4_Track::TYPE_VIDEO) {
                anchor_cursor = cursors[i];
                break;
            }
        }
    }
    if (anchor_cursor == NULL) {
        // no video track to anchor with, pick the first audio track
        for (unsigned int i=0; i<cursors.ItemCount(); i++) {
            if (cursors[i]->m_Track->GetType() == AP4_Track::TYPE_AUDIO) {
                anchor_cursor = cursors[i];
                break;
            }
        }
        // no audio track to anchor with, pick the first subtitles track
        for (unsigned int i=0; i<cursors.ItemCount(); i++) {
            if (cursors[i]->m_Track->GetType() == AP4_Track::TYPE_SUBTITLES) {
                anchor_cursor = cursors[i];
                break;
            }
        }
    }
    if (anchor_cursor == NULL) {
        // this shoudl never happen
        fprintf(stderr, "ERROR: no anchor track\n");
        return;
    }
    if (create_segment_index) {
        index_cursor = anchor_cursor;
    }
    if (Options.debug) {
        printf("Using track ID %d as anchor\n", anchor_cursor->m_Track->GetId());
    }
    
    // update the mehd duration
    mehd->SetDuration(output_movie->GetDuration());
    
    // add the mvex container to the moov container
    output_movie->GetMoovAtom()->AddChild(mvex);
    
    // compute all the fragments
    unsigned int sequence_number = 1;
    for(;;) {
        TrackCursor* cursor = NULL;

        // pick the first track with a fragment index lower than the anchor's
        for (unsigned int i=0; i<cursors.ItemCount(); i++) {
            if (track_id && cursors[i]->m_Track->GetId() != track_id) continue;
            if (cursors[i]->m_Eos) continue;
            if (cursors[i]->m_FragmentIndex < anchor_cursor->m_FragmentIndex) {
                cursor = cursors[i];
                break;
            }
        }
        
        // check if we found a non-anchor cursor to use
        if (cursor == NULL) {
            // the anchor should be used in this round, check if we can use it
            if (anchor_cursor->m_Eos) {
                // the anchor is done, pick a new anchor unless we need to trim
                anchor_cursor = NULL;
                if (!Options.trim) {
                    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
                        if (track_id && cursors[i]->m_Track->GetId() != track_id) continue;
                        if (cursors[i]->m_Eos) continue;
                        if (anchor_cursor == NULL ||
                            cursors[i]->m_Track->GetType() == AP4_Track::TYPE_VIDEO ||
                            cursors[i]->m_Track->GetType() == AP4_Track::TYPE_AUDIO) {
                            anchor_cursor = cursors[i];
                            if (Options.debug) {
                                printf("+++ New anchor: Track ID %d\n", anchor_cursor->m_Track->GetId());
                            }
                        }
                    }
                }
            }
            cursor = anchor_cursor;
        }
        if (cursor == NULL) break; // all done
        
        // decide how many samples go into this fragment
        AP4_UI64 target_dts;
        if (cursor == anchor_cursor) {
            // compute the current dts in milliseconds
            AP4_UI64 anchor_dts_ms = AP4_ConvertTime(cursor->m_Sample.GetDts(),
                                                     cursor->m_Track->GetMediaTimeScale(),
                                                     1000);
            // round to the nearest multiple of fragment_duration
            AP4_UI64 anchor_position = (anchor_dts_ms + (fragment_duration/2))/fragment_duration;
            
            // pick the next fragment_duration multiple at our target
            target_dts = AP4_ConvertTime(fragment_duration*(anchor_position+1),
                                         1000,
                                         cursor->m_Track->GetMediaTimeScale());
        } else {
            target_dts = AP4_ConvertTime(anchor_cursor->m_Sample.GetDts(),
                                         anchor_cursor->m_Track->GetMediaTimeScale(),
                                         cursor->m_Track->GetMediaTimeScale());
            if (target_dts <= cursor->m_Sample.GetDts()) {
                // we must be at the end, past the last anchor sample, just use the target duration
                target_dts = AP4_ConvertTime(fragment_duration*(cursor->m_FragmentIndex+1),
                                            1000,
                                            cursor->m_Track->GetMediaTimeScale());
                
                if (target_dts <= cursor->m_Sample.GetDts()) {
                    // we're still behind, there may have been an alignment/rounding error, just advance by one segment duration
                    target_dts = cursor->m_Sample.GetDts()+AP4_ConvertTime(fragment_duration,
                                                                           1000,
                                                                           cursor->m_Track->GetMediaTimeScale());
                }
            }
        }

        unsigned int end_sample_index = cursor->m_Samples->GetSampleCount();
        AP4_UI64 smallest_diff = (AP4_UI64)(0xFFFFFFFFFFFFFFFFULL);
        AP4_Sample sample;
        for (unsigned int i=cursor->m_SampleIndex+1; i<=cursor->m_Samples->GetSampleCount(); i++) {
            AP4_UI64 dts;
            if (i < cursor->m_Samples->GetSampleCount()) {
                result = cursor->m_Samples->GetSample(i, sample);
                if (AP4_FAILED(result)) {
                    fprintf(stderr, "ERROR: failed to get sample %d (%d)\n", i, result);
                    return;
                }
                if (!sample.IsSync()) continue; // only look for sync samples
                dts = sample.GetDts();
            } else {
                result = cursor->m_Samples->GetSample(i-1, sample);
                if (AP4_FAILED(result)) {
                    fprintf(stderr, "ERROR: failed to get sample %d (%d)\n", i-1, result);
                    return;
                }
                dts = sample.GetDts()+sample.GetDuration();
            }
            AP4_SI64 diff = dts-target_dts;
            AP4_UI64 abs_diff = diff<0?-diff:diff;
            if (abs_diff < smallest_diff) {
                // this sample is the closest to the target so far
                end_sample_index = i;
                smallest_diff = abs_diff;
            }
            if (diff >= 0) {
                // this sample is past the target, it is not going to get any better, stop looking
                break;
            }
        }
        if (cursor->m_Eos) continue;
        
        if (Options.debug) {
            if (cursor == anchor_cursor) {
                printf("====");
            } else {
                printf("----");
            }
            printf(" Track ID %d - dts=%lld, target=%lld, start=%d, end=%d/%d\n",
                   cursor->m_Track->GetId(),
                   cursor->m_Sample.GetDts(),
                   target_dts,
                   cursor->m_SampleIndex,
                   end_sample_index,
                   cursor->m_Track->GetSampleCount());
        }
        
        // emit a fragment for the selected track
        if (Options.verbosity > 1) {
            printf("fragment: track ID %d ", cursor->m_Track->GetId());
        }

        // decide which sample description index to use
        // (this is not very sophisticated, we only look at the sample description
        // index of the first sample in the group, which may not be correct. This
        // should be fixed later)
        unsigned int sample_desc_index = cursor->m_Sample.GetDescriptionIndex();
        unsigned int tfhd_flags = AP4_TFHD_FLAG_DEFAULT_BASE_IS_MOOF;
        if (sample_desc_index > 0) {
            tfhd_flags |= AP4_TFHD_FLAG_SAMPLE_DESCRIPTION_INDEX_PRESENT;
        }
        if (cursor->m_Track->GetType() == AP4_Track::TYPE_VIDEO) {
            tfhd_flags |= AP4_TFHD_FLAG_DEFAULT_SAMPLE_FLAGS_PRESENT;
        }
        
        // setup the moof structure
        AP4_ContainerAtom* moof = new AP4_ContainerAtom(AP4_ATOM_TYPE_MOOF);
        AP4_MfhdAtom* mfhd = new AP4_MfhdAtom(sequence_number++);
        moof->AddChild(mfhd);
        AP4_ContainerAtom* traf = new AP4_ContainerAtom(AP4_ATOM_TYPE_TRAF);
        AP4_TfhdAtom* tfhd = new AP4_TfhdAtom(tfhd_flags,
                                              cursor->m_Track->GetId(),
                                              0,
                                              sample_desc_index+1,
                                              0,
                                              0,
                                              0);
        if (tfhd_flags & AP4_TFHD_FLAG_DEFAULT_SAMPLE_FLAGS_PRESENT) {
            tfhd->SetDefaultSampleFlags(0x1010000); // sample_is_non_sync_sample=1, sample_depends_on=1 (not I frame)
        }
        
        traf->AddChild(tfhd);
        if (!Options.no_tfdt) {
            AP4_TfdtAtom* tfdt = new AP4_TfdtAtom(1, cursor->m_Timestamp);
            traf->AddChild(tfdt);
        }
        AP4_UI32 trun_flags = AP4_TRUN_FLAG_DATA_OFFSET_PRESENT     |
                              AP4_TRUN_FLAG_SAMPLE_DURATION_PRESENT |
                              AP4_TRUN_FLAG_SAMPLE_SIZE_PRESENT;
        AP4_UI32 first_sample_flags = 0;
        if (cursor->m_Track->GetType() == AP4_Track::TYPE_VIDEO) {
            trun_flags |= AP4_TRUN_FLAG_FIRST_SAMPLE_FLAGS_PRESENT;
            first_sample_flags = 0x2000000; // sample_depends_on=2 (I frame)
        }
        AP4_TrunAtom* trun = new AP4_TrunAtom(trun_flags, 0, first_sample_flags);
        
        traf->AddChild(trun);
        moof->AddChild(traf);
        
        // create a new FragmentInfo object to store the fragment details
        FragmentInfo* fragment = new FragmentInfo(cursor->m_Samples, cursor->m_Tfra, cursor->m_Timestamp, moof);
        fragments.Add(fragment);
        
        // add samples to the fragment
        unsigned int                   sample_count = 0;
        AP4_Array<AP4_TrunAtom::Entry> trun_entries;
        fragment->m_MdatSize = AP4_ATOM_HEADER_SIZE;
        for (;;) {
            // if we have one non-zero CTS delta, we'll need to express it
            if (cursor->m_Sample.GetCtsDelta()) {
                trun->SetFlags(trun->GetFlags() | AP4_TRUN_FLAG_SAMPLE_COMPOSITION_TIME_OFFSET_PRESENT);
            }
            
            // add one sample
            trun_entries.SetItemCount(sample_count+1);
            AP4_TrunAtom::Entry& trun_entry = trun_entries[sample_count];
            trun_entry.sample_duration                = timescale?
                                                        (AP4_UI32)AP4_ConvertTime(cursor->m_Sample.GetDuration(),
                                                                                  cursor->m_Track->GetMediaTimeScale(),
                                                                                  timescale):
                                                        cursor->m_Sample.GetDuration();
            trun_entry.sample_size                    = cursor->m_Sample.GetSize();
            trun_entry.sample_composition_time_offset = timescale?
                                                        (AP4_UI32)AP4_ConvertTime(cursor->m_Sample.GetCtsDelta(),
                                                                                  cursor->m_Track->GetMediaTimeScale(),
                                                                                  timescale):
                                                        cursor->m_Sample.GetCtsDelta();
                        
            fragment->m_SampleIndexes.SetItemCount(sample_count+1);
            fragment->m_SampleIndexes[sample_count] = cursor->m_SampleIndex;
            fragment->m_MdatSize += trun_entry.sample_size;
            fragment->m_Duration += trun_entry.sample_duration;
            
            // next sample
            cursor->m_Timestamp += trun_entry.sample_duration;
            result = cursor->SetSampleIndex(cursor->m_SampleIndex+1);
            if (AP4_FAILED(result)) {
                fprintf(stderr, "ERROR: failed to get sample %d (%d)\n", cursor->m_SampleIndex+1, result);
                return;
            }
            sample_count++;
            if (cursor->m_Eos) {
                if (Options.debug) {
                    printf("[Track ID %d has reached the end]\n", cursor->m_Track->GetId());
                }
                break;
            }
            if (cursor->m_SampleIndex >= end_sample_index) {
                break; // done with this fragment
            }
        }
        if (Options.verbosity > 1) {
            printf(" %d samples\n", sample_count);
        }
                
        // update moof and children
        trun->SetEntries(trun_entries);
        trun->SetDataOffset((AP4_UI32)moof->GetSize()+AP4_ATOM_HEADER_SIZE);
        
        // advance the cursor's fragment index
        ++cursor->m_FragmentIndex;
    }
    
    // write the ftyp atom
    AP4_FtypAtom* ftyp = input_file.GetFileType();
    if (ftyp) {
        // keep the existing brand and compatible brands
        AP4_Array<AP4_UI32> compatible_brands;
        compatible_brands.EnsureCapacity(ftyp->GetCompatibleBrands().ItemCount()+1);
        for (unsigned int i=0; i<ftyp->GetCompatibleBrands().ItemCount(); i++) {
            compatible_brands.Append(ftyp->GetCompatibleBrands()[i]);
        }
        
        // add the compatible brand if it is not already there
        if (!ftyp->HasCompatibleBrand(AP4_FILE_BRAND_ISO5)) {
            compatible_brands.Append(AP4_FILE_BRAND_ISO5);
        }

        // create a replacement
        AP4_FtypAtom* new_ftyp = new AP4_FtypAtom(ftyp->GetMajorBrand(),
                                                  ftyp->GetMinorVersion(),
                                                  &compatible_brands[0],
                                                  compatible_brands.ItemCount());
        ftyp = new_ftyp;
    } else {
        AP4_UI32 compat = AP4_FILE_BRAND_ISO5;
        ftyp = new AP4_FtypAtom(AP4_FTYP_BRAND_MP42, 0, &compat, 1);
    }
    ftyp->Write(output_stream);
    delete ftyp;
    
    // write the moov atom
    output_movie->GetMoovAtom()->Write(output_stream);

    // write the (not-yet fully computed) index if needed
    AP4_SidxAtom* sidx = NULL;
    AP4_Position  sidx_position = 0;
    output_stream.Tell(sidx_position);
    if (create_segment_index) {
        sidx = new AP4_SidxAtom(index_cursor->m_Track->GetId(),
                                index_cursor->m_Track->GetMediaTimeScale(),
                                0,
                                0);
        // reserve space for the entries now, but they will be computed and updated later
        sidx->SetReferenceCount(fragments.ItemCount());
        sidx->Write(output_stream);
    }
    
    // write all fragments
    for (AP4_List<FragmentInfo>::Item* item = fragments.FirstItem();
                                       item;
                                       item = item->GetNext()) {
        FragmentInfo* fragment = item->GetData();

        // remember the time and position of this fragment
        output_stream.Tell(fragment->m_MoofPosition);
        fragment->m_Tfra->AddEntry(fragment->m_Timestamp, fragment->m_MoofPosition);
        
        // write the moof
        fragment->m_Moof->Write(output_stream);
        
        // write mdat
        output_stream.WriteUI32(fragment->m_MdatSize);
        output_stream.WriteUI32(AP4_ATOM_TYPE_MDAT);
        AP4_DataBuffer sample_data;
        AP4_Sample     sample;
        for (unsigned int i=0; i<fragment->m_SampleIndexes.ItemCount(); i++) {
            // get the sample
            result = fragment->m_Samples->GetSample(fragment->m_SampleIndexes[i], sample);
            if (AP4_FAILED(result)) {
                fprintf(stderr, "ERROR: failed to get sample %d (%d)\n", fragment->m_SampleIndexes[i], result);
                return;
            }

            // read the sample data
            result = sample.ReadData(sample_data);
            if (AP4_FAILED(result)) {
                fprintf(stderr, "ERROR: failed to read sample data for sample %d (%d)\n", fragment->m_SampleIndexes[i], result);
                return;
            }
            
            // write the sample data
            result = output_stream.Write(sample_data.GetData(), sample_data.GetDataSize());
            if (AP4_FAILED(result)) {
                fprintf(stderr, "ERROR: failed to write sample data (%d)\n", result);
                return;
            }
        }
    }

    // update the index and re-write it if needed
    if (create_segment_index) {
        unsigned int segment_index = 0;
        AP4_SidxAtom::Reference reference;
        for (AP4_List<FragmentInfo>::Item* item = fragments.FirstItem();
                                           item;
                                           item = item->GetNext()) {
            FragmentInfo* fragment = item->GetData();
            reference.m_ReferencedSize     = (AP4_UI32)(fragment->m_Moof->GetSize()+fragment->m_MdatSize);
            reference.m_SubsegmentDuration = fragment->m_Duration;
            reference.m_StartsWithSap      = true;
            sidx->SetReference(segment_index++, reference);
        }
        AP4_Position here = 0;
        output_stream.Tell(here);
        output_stream.Seek(sidx_position);
        sidx->Write(output_stream);
        output_stream.Seek(here);
        delete sidx;
    }
    
    // create an mfra container and write out the index
    AP4_ContainerAtom mfra(AP4_ATOM_TYPE_MFRA);
    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
        if (track_id && cursors[i]->m_Track->GetId() != track_id) {
            continue;
        }
        mfra.AddChild(cursors[i]->m_Tfra);
        cursors[i]->m_Tfra = NULL;
    }
    AP4_MfroAtom* mfro = new AP4_MfroAtom((AP4_UI32)mfra.GetSize()+16);
    mfra.AddChild(mfro);
    result = mfra.Write(output_stream);
    if (AP4_FAILED(result)) {
        fprintf(stderr, "ERROR: failed to write 'mfra' (%d)\n", result);
        return;
    }
    
    // cleanup
    fragments.DeleteReferences();
    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
        delete cursors[i];
    }
    for (AP4_List<FragmentInfo>::Item* item = fragments.FirstItem();
                                       item;
                                       item = item->GetNext()) {
        FragmentInfo* fragment = item->GetData();
        delete fragment->m_Moof;
    }
    delete output_movie;
}
Exemplo n.º 4
0
/*----------------------------------------------------------------------
|   AP4_Processor::ProcessFragments
+---------------------------------------------------------------------*/
AP4_Result
AP4_Processor::ProcessFragment( AP4_ContainerAtom*		    moof,
                                AP4_SidxAtom*			    sidx,
                                AP4_Position			    sidx_position,
                                AP4_ByteStream&			    output,
								AP4_Array<AP4_Position>&    moof_positions,
								AP4_Array<AP4_Position>&    mdat_positions)
{
	unsigned int fragment_index = 0;
    
    //AP4_UI64           mdat_payload_offset = atom_offset+atom->GetSize()+AP4_ATOM_HEADER_SIZE;
    AP4_Sample         sample;
    AP4_DataBuffer     sample_data_in;
    AP4_DataBuffer     sample_data_out;
    AP4_Result         result = AP4_SUCCESS;
        
    // parse the moof
    //AP4_MovieFragment* fragment = new AP4_MovieFragment(moof);

    // process all the traf atoms
    AP4_Array<AP4_Processor::FragmentHandler*> handlers;
    AP4_Array<AP4_FragmentSampleTable*> sample_tables;

	for (; AP4_Atom* child = moof->GetChild(AP4_ATOM_TYPE_TRAF, handlers.ItemCount());) {
		AP4_TrafAtom* traf = AP4_DYNAMIC_CAST(AP4_TrafAtom, child);

		PERTRACK &track_data(m_TrackData[traf->GetInternalTrackId()]);
		AP4_TrakAtom* trak = track_data.track_handler->GetTrakAtom();
		AP4_TrexAtom* trex = track_data.track_handler->GetTrexAtom();

		// create the handler for this traf
		AP4_Processor::FragmentHandler* handler = CreateFragmentHandler(trak, trex, traf,
			*(m_StreamData[track_data.streamId].stream),
			moof_positions[track_data.streamId]);
		if (handler) {
			result = handler->ProcessFragment();
			if (AP4_FAILED(result)) return result;
		}
		handlers.Append(handler);

		// create a sample table object so we can read the sample data
		AP4_FragmentSampleTable* sample_table = new AP4_FragmentSampleTable(
			traf,
			trex,
      traf->GetInternalTrackId(),
			m_StreamData[track_data.streamId].stream,
			moof_positions[traf->GetInternalTrackId()],
			mdat_positions[traf->GetInternalTrackId()],
			0);
		sample_tables.Append(sample_table);

		// let the handler look at the samples before we process them
		if (handler)
			result = handler->PrepareForSamples(sample_table);
		if (AP4_FAILED(result))
			return result;
	}
             
	output.Buffer();
		
	// write the moof
    AP4_UI64 moof_out_start = 0;
    output.Tell(moof_out_start);
    moof->Write(output);
        
    // remember the location of this fragment
	FragmentMapEntry map_entry = { moof_positions[0], moof_out_start };
    fragment_map_.Append(map_entry);

    // write an mdat header
    AP4_Position mdat_out_start;
    AP4_UI64 mdat_size = AP4_ATOM_HEADER_SIZE;
    output.Tell(mdat_out_start);
    output.WriteUI32(0);
    output.WriteUI32(AP4_ATOM_TYPE_MDAT);

    // process all track runs
    for (unsigned int i=0; i<handlers.ItemCount(); i++) {
        AP4_Processor::FragmentHandler* handler = handlers[i];

        // get the track ID
        AP4_ContainerAtom* traf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, moof->GetChild(AP4_ATOM_TYPE_TRAF, i));
        if (traf == NULL) continue;
        AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD));
            
        // compute the base data offset
        AP4_UI64 base_data_offset;
        if (tfhd->GetFlags() & AP4_TFHD_FLAG_BASE_DATA_OFFSET_PRESENT) {
            base_data_offset = mdat_out_start+AP4_ATOM_HEADER_SIZE;
        } else {
            base_data_offset = moof_out_start;
        }
            
        // build a list of all trun atoms
        AP4_Array<AP4_TrunAtom*> truns;
        for (AP4_List<AP4_Atom>::Item* child_item = traf->GetChildren().FirstItem();
                                        child_item;
                                        child_item = child_item->GetNext()) {
            AP4_Atom* child_atom = child_item->GetData();
            if (child_atom->GetType() == AP4_ATOM_TYPE_TRUN) {
                AP4_TrunAtom* trun = AP4_DYNAMIC_CAST(AP4_TrunAtom, child_atom);
                truns.Append(trun);
            }
        }    
        AP4_Ordinal   trun_index        = 0;
        AP4_Ordinal   trun_sample_index = 0;
        AP4_TrunAtom* trun = truns[0];
        trun->SetDataOffset((AP4_SI32)((mdat_out_start+mdat_size)-base_data_offset));
            
        // write the mdat
        for (unsigned int j=0; j<sample_tables[i]->GetSampleCount(); j++, trun_sample_index++) {
            // advance the trun index if necessary
            if (trun_sample_index >= trun->GetEntries().ItemCount()) {
                trun = truns[++trun_index];
                trun->SetDataOffset((AP4_SI32)((mdat_out_start+mdat_size)-base_data_offset));
                trun_sample_index = 0;
            }
                
            // get the next sample
            result = sample_tables[i]->GetSample(j, sample);
            if (AP4_FAILED(result)) return result;
            sample.ReadData(sample_data_in);
                
            m_TrackData[sample_tables[i]->GetInteralTrackId()].dts = sample.GetDts();
            
            // process the sample data
            if (handler) {
                result = handler->ProcessSample(sample_data_in, sample_data_out);
                if (AP4_FAILED(result)) return result;

                // write the sample data
                result = output.Write(sample_data_out.GetData(), sample_data_out.GetDataSize());
                if (AP4_FAILED(result)) return result;

                // update the mdat size
                mdat_size += sample_data_out.GetDataSize();
                    
                // update the trun entry
                trun->UseEntries()[trun_sample_index].sample_size = sample_data_out.GetDataSize();
            } else {
                // write the sample data (unmodified)
                result = output.Write(sample_data_in.GetData(), sample_data_in.GetDataSize());
                if (AP4_FAILED(result)) return result;

                // update the mdat size
                mdat_size += sample_data_in.GetDataSize();
            }
        }

        if (handler) {
            // update the tfhd header
            if (tfhd->GetFlags() & AP4_TFHD_FLAG_BASE_DATA_OFFSET_PRESENT) {
                tfhd->SetBaseDataOffset(mdat_out_start+AP4_ATOM_HEADER_SIZE);
            }
            if (tfhd->GetFlags() & AP4_TFHD_FLAG_DEFAULT_SAMPLE_SIZE_PRESENT) {
                tfhd->SetDefaultSampleSize(trun->GetEntries()[0].sample_size);
            }
                
            // give the handler a chance to update the atoms
            handler->FinishFragment();
        }
    }

    // update the mdat header
    AP4_Position mdat_out_end;
    output.Tell(mdat_out_end);
#if defined(AP4_DEBUG)
    AP4_ASSERT(mdat_out_end-mdat_out_start == mdat_size);
#endif
	if (AP4_FAILED(result = output.Seek(mdat_out_start)))
		return result;
    output.WriteUI32((AP4_UI32)mdat_size);
    output.Seek(mdat_out_end);
        
    // update the moof if needed
	if (AP4_FAILED(result = output.Seek(moof_out_start)))
		return result;
    moof->Write(output);
    output.Seek(mdat_out_end);
        
    // update the sidx if we have one
    if (sidx && fragment_index < sidx->GetReferences().ItemCount()) {
        if (fragment_index == 0) {
            sidx->SetFirstOffset(moof_out_start-(sidx_position+sidx->GetSize()));
        }
        AP4_LargeSize fragment_size = mdat_out_end-moof_out_start;
        AP4_SidxAtom::Reference& sidx_ref = sidx->UseReferences()[fragment_index];
        sidx_ref.m_ReferencedSize = (AP4_UI32)fragment_size;
    }
        
    // cleanup
    //delete fragment;
        
    for (unsigned int i=0; i<handlers.ItemCount(); i++) {
        delete handlers[i];
    }
    for (unsigned int i=0; i<sample_tables.ItemCount(); i++) {
        delete sample_tables[i];
    }
	if (AP4_FAILED(result = output.Flush()))
		return result;
    
    return AP4_SUCCESS;
}
Exemplo n.º 5
0
/*----------------------------------------------------------------------
|   AP4_Movie::ProcessMoof
+---------------------------------------------------------------------*/
void
AP4_Movie::ProcessMoof(AP4_ContainerAtom* moof, AP4_ByteStream& stream)
{
	if (moof) {
		AP4_Offset offset = 0;
		stream.Tell(offset);
		AP4_Offset moof_offset = offset - moof->GetSize();
		AP4_Offset mdat_payload_offset = offset + 8;

		AP4_MfhdAtom* mfhd = AP4_DYNAMIC_CAST(AP4_MfhdAtom, moof->GetChild(AP4_ATOM_TYPE_MFHD));
		if (mfhd) {
			for (AP4_List<AP4_Atom>::Item* item = moof->GetChildren().FirstItem();
										   item;
										   item = item->GetNext()) {
				AP4_Atom* atom = item->GetData();
				if (atom->GetType() == AP4_ATOM_TYPE_TRAF) {
					AP4_ContainerAtom* traf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, atom);
					if (traf) {
						AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD));
						if (!tfhd) {
							continue;
						}
						AP4_Track* track = GetTrack(tfhd->GetTrackId());
						if (!track) {
							continue;
						}

						AP4_TfdtAtom* tfdt = AP4_DYNAMIC_CAST(AP4_TfdtAtom, traf->GetChild(AP4_ATOM_TYPE_TFDT));

						AP4_TrexAtom*      trex = NULL;
						AP4_ContainerAtom* mvex = AP4_DYNAMIC_CAST(AP4_ContainerAtom, m_MoovAtom->GetChild(AP4_ATOM_TYPE_MVEX));
						if (mvex) {
							for (AP4_List<AP4_Atom>::Item* child_item = mvex->GetChildren().FirstItem();
														   child_item;
														   child_item = child_item->GetNext()) {
								AP4_Atom* child_atom = child_item->GetData();
								if (child_atom->GetType() == AP4_ATOM_TYPE_TREX) {
									trex = AP4_DYNAMIC_CAST(AP4_TrexAtom, child_atom);
									if (trex && trex->GetTrackId() == tfhd->GetTrackId()) break;
									trex = NULL;
								}
							}
						}

						AP4_FragmentSampleTable* sampleTable = track->GetFragmentSampleTable();

						AP4_Cardinal sample_count = 0;
						for (AP4_List<AP4_Atom>::Item* child_item = traf->GetChildren().FirstItem();
													   child_item;
													   child_item = child_item->GetNext()) {
							AP4_Atom* child_atom = child_item->GetData();
							if (child_atom->GetType() == AP4_ATOM_TYPE_TRUN) {
								AP4_TrunAtom* trun = AP4_DYNAMIC_CAST(AP4_TrunAtom, child_atom);
								if (trun) {
									sample_count += trun->GetEntries().ItemCount();
								}
							}
						}

						if (!sample_count) {
							return;
						}

						if (sampleTable->GetSampleCount() == 0) {
							track->CreateFragmentFromStdSamples();
						}

						if (AP4_FAILED(sampleTable->EnsureCapacity(sample_count + sampleTable->GetSampleCount()))) {
							return;
						}

						AP4_UI64 dts_origin = tfdt ? tfdt->GetBaseMediaDecodeTime() : 0;
						for (AP4_List<AP4_Atom>::Item* child_item = traf->GetChildren().FirstItem();
													   child_item;
													   child_item = child_item->GetNext()) {
							AP4_Atom* child_atom = child_item->GetData();
							if (child_atom->GetType() == AP4_ATOM_TYPE_TRUN) {
								AP4_TrunAtom* trun = AP4_DYNAMIC_CAST(AP4_TrunAtom, child_atom);
								if (trun) {
									sampleTable->AddTrun(trun, tfhd, trex, stream, dts_origin, moof_offset, mdat_payload_offset);
								}
							}
						}
					}
				}
			}
		}
	}
}
Exemplo n.º 6
0
/*----------------------------------------------------------------------
|   Fragment
+---------------------------------------------------------------------*/
static void
Fragment(AP4_File&       input_file,
         AP4_ByteStream& output_stream,
         unsigned int    fragment_duration,
         AP4_UI32        timescale)
{
    AP4_Result result;
    
    AP4_Movie* input_movie = input_file.GetMovie();
    if (input_movie == NULL) {
        fprintf(stderr, "ERROR: no moov found in the input file\n");
        return;
    }

    // create the output file object
    AP4_Movie* output_movie = new AP4_Movie(1000);
    
    // create an mvex container
    AP4_ContainerAtom* mvex = new AP4_ContainerAtom(AP4_ATOM_TYPE_MVEX);
    AP4_MehdAtom* mehd = new AP4_MehdAtom(0); 
    mvex->AddChild(mehd);
    
    // create a cusor list to keep track of the tracks we will read from
    AP4_Array<TrackCursor*> cursors;
    
    // add an output track for each track in the input file
    for (AP4_List<AP4_Track>::Item* track_item = input_movie->GetTracks().FirstItem();
                                    track_item;
                                    track_item = track_item->GetNext()) {
        AP4_Track* track = track_item->GetData();
        TrackCursor* cursor = new TrackCursor();
        cursor->m_TrackId = track->GetId();
        cursor->m_Tfra->SetTrackId(track->GetId());
        cursors.Append(cursor);
                    
        // create a sample table (with no samples) to hold the sample description
        AP4_SyntheticSampleTable* sample_table = new AP4_SyntheticSampleTable();
        for (unsigned int i=0; i<track->GetSampleDescriptionCount(); i++) {
            AP4_SampleDescription* sample_description = track->GetSampleDescription(i);
            sample_table->AddSampleDescription(sample_description, false);
        }
        
        // create the track
        AP4_Track* output_track = new AP4_Track(track->GetType(),
                                                sample_table,
                                                cursor->m_TrackId,
                                                timescale?timescale:1000,
                                                AP4_ConvertTime(track->GetDuration(),
                                                                input_movie->GetTimeScale(),
                                                                timescale?timescale:1000),
                                                timescale?timescale:track->GetMediaTimeScale(),
                                                0,//track->GetMediaDuration(),
                                                track->GetTrackLanguage(),
                                                track->GetWidth(),
                                                track->GetHeight());
        output_movie->AddTrack(output_track);
        result = cursor->SetTrack(track);
        if (AP4_FAILED(result)) {
            fprintf(stderr, "ERROR: failed to read sample (%d)\n", result);
            return;
        }
                
        // add a trex entry to the mvex container
        AP4_TrexAtom* trex = new AP4_TrexAtom(cursor->m_TrackId,
                                              1,
                                              0,
                                              0,
                                              0);
        mvex->AddChild(trex);
    }
    
    if (cursors.ItemCount() == 0) {
        fprintf(stderr, "ERROR: no track found\n");
        return;
    }

    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
        if (cursors[i]->m_Track->GetType() == AP4_Track::TYPE_VIDEO) {
            cursors[i]->m_TargetDuration = AP4_ConvertTime(fragment_duration>AP4_FRAGMENTER_FRAGMENT_DURATION_TOLERANCE ?
                                                           fragment_duration-AP4_FRAGMENTER_FRAGMENT_DURATION_TOLERANCE : 0,
                                                           1000,
                                                           cursors[i]->m_Track->GetMediaTimeScale());
        } else {
            cursors[i]->m_TargetDuration = AP4_ConvertTime(fragment_duration,
                                                           1000,
                                                           cursors[i]->m_Track->GetMediaTimeScale());
        }
    }
    
    // update the mehd duration
    mehd->SetDuration(output_movie->GetDuration());
    
    // the mvex container to the moov container
    output_movie->GetMoovAtom()->AddChild(mvex);
    
    // write the ftyp atom
    AP4_FtypAtom* ftyp = input_file.GetFileType();
    if (ftyp) {
        ftyp->Write(output_stream);
    }
                 
    // write the moov atom
    output_movie->GetMoovAtom()->Write(output_stream);
    
    // write all the fragments
    unsigned int sequence_number = 1;
    for(;;) {
        // select the next track to read from
        TrackCursor* cursor = NULL;
        AP4_UI64 min_dts = (AP4_UI64)(-1);
        for (unsigned int i=0; i<cursors.ItemCount(); i++) {
            if (cursors[i]->m_Eos) continue;
            AP4_UI64 dts = AP4_ConvertTime(cursors[i]->m_Sample.GetDts(),
                                           cursors[i]->m_Track->GetMediaTimeScale(),
                                           AP4_FRAGMENTER_BASE_TIMESCALE);
            if (dts < min_dts) {
                min_dts = dts;
                cursor = cursors[i];
            }
        }
        if (cursor == NULL) break; // all done
        
        // compute the target end for the segment
        cursor->m_EndDts = cursor->m_Sample.GetDts()+cursor->m_TargetDuration;
        
        // emit a fragment for the selected track
        if (Options.verbosity > 0) {
            printf("fragment: track ID %d ", cursor->m_Track->GetId());
        }

        // remember the time and position of this fragment
        AP4_Position moof_offset = 0;
        output_stream.Tell(moof_offset);
        cursor->m_Tfra->AddEntry(cursor->m_Timestamp, moof_offset);
        
        // decide which sample description index to use
        // (this is not very sophisticated, we only look at the sample description
        // index of the first sample in the group, which may not be correct. This
        // should be fixed later)
        unsigned int sample_desc_index = cursor->m_Sample.GetDescriptionIndex();
        unsigned int tfhd_flags = AP4_TFHD_FLAG_DEFAULT_BASE_IS_MOOF;
        if (sample_desc_index > 0) {
            tfhd_flags |= AP4_TFHD_FLAG_SAMPLE_DESCRIPTION_INDEX_PRESENT;
        }
        if (cursor->m_Track->GetType() == AP4_Track::TYPE_VIDEO) {
            tfhd_flags |= AP4_TFHD_FLAG_DEFAULT_SAMPLE_FLAGS_PRESENT;
        }
            
        // setup the moof structure
        AP4_ContainerAtom* moof = new AP4_ContainerAtom(AP4_ATOM_TYPE_MOOF);
        AP4_MfhdAtom* mfhd = new AP4_MfhdAtom(sequence_number++);
        moof->AddChild(mfhd);
        AP4_ContainerAtom* traf = new AP4_ContainerAtom(AP4_ATOM_TYPE_TRAF);
        AP4_TfhdAtom* tfhd = new AP4_TfhdAtom(tfhd_flags,
                                              cursor->m_TrackId,
                                              0,
                                              sample_desc_index+1,
                                              0,
                                              0,
                                              0);
        if (tfhd_flags & AP4_TFHD_FLAG_DEFAULT_SAMPLE_FLAGS_PRESENT) {
            tfhd->SetDefaultSampleFlags(0x1010000); // sample_is_non_sync_sample=1, sample_depends_on=1 (not I frame)
        }
        
        traf->AddChild(tfhd);
        AP4_TfdtAtom* tfdt = new AP4_TfdtAtom(1, cursor->m_Timestamp);
        traf->AddChild(tfdt);
        AP4_UI32 trun_flags = AP4_TRUN_FLAG_DATA_OFFSET_PRESENT     |
                              AP4_TRUN_FLAG_SAMPLE_DURATION_PRESENT |
                              AP4_TRUN_FLAG_SAMPLE_SIZE_PRESENT;
        AP4_UI32 first_sample_flags = 0;
        if (cursor->m_Track->GetType() == AP4_Track::TYPE_VIDEO) {
            trun_flags |= AP4_TRUN_FLAG_FIRST_SAMPLE_FLAGS_PRESENT;
            first_sample_flags = 0x2000000; // sample_depends_on=2 (I frame)
        }
        AP4_TrunAtom* trun = new AP4_TrunAtom(trun_flags, 0, first_sample_flags);
        
        traf->AddChild(trun);
        moof->AddChild(traf);
            
        // decide which samples go in this fragment
        AP4_Array<AP4_UI32>            sample_indexes;
        unsigned int                   sample_count = 0;
        AP4_Array<AP4_TrunAtom::Entry> trun_entries;
        AP4_UI32                       mdat_size = AP4_ATOM_HEADER_SIZE;
        for (;;) {
            // if we have one non-zero CTS delta, we'll need to express it
            if (cursor->m_Sample.GetCtsDelta()) {
                trun->SetFlags(trun->GetFlags() | AP4_TRUN_FLAG_SAMPLE_COMPOSITION_TIME_OFFSET_PRESENT);
            }
            
            // add one sample
            trun_entries.SetItemCount(sample_count+1);
            AP4_TrunAtom::Entry& trun_entry = trun_entries[sample_count];
            trun_entry.sample_duration                = timescale?
                                                        (AP4_UI32)AP4_ConvertTime(cursor->m_Sample.GetDuration(),
                                                                                  cursor->m_Track->GetMediaTimeScale(),
                                                                                  timescale):
                                                        cursor->m_Sample.GetDuration();
            trun_entry.sample_size                    = cursor->m_Sample.GetSize();
            trun_entry.sample_composition_time_offset = timescale?
                                                        (AP4_UI32)AP4_ConvertTime(cursor->m_Sample.GetCtsDelta(),
                                                                                  cursor->m_Track->GetMediaTimeScale(),
                                                                                  timescale):
                                                        cursor->m_Sample.GetCtsDelta();
                        
            sample_indexes.SetItemCount(sample_count+1);
            sample_indexes[sample_count] = cursor->m_SampleIndex;
            mdat_size += trun_entry.sample_size;
            
            // next sample
            cursor->m_Timestamp += trun_entry.sample_duration;
            cursor->m_SampleIndex++;
            sample_count++;
            if (cursor->m_SampleIndex >= cursor->m_Track->GetSampleCount()) {
                cursor->m_Eos = true;

                AP4_UI64 end_dts = cursor->m_Sample.GetDts()+cursor->m_Sample.GetDuration();
                cursor->m_Sample.Reset();
                cursor->m_Sample.SetDts(end_dts);

                break;
            }
            result = cursor->m_Track->GetSample(cursor->m_SampleIndex, cursor->m_Sample);
            if (AP4_FAILED(result)) {
                cursor->m_Eos = true;

                AP4_UI64 end_dts = cursor->m_Sample.GetDts()+cursor->m_Sample.GetDuration();
                cursor->m_Sample.Reset();
                cursor->m_Sample.SetDts(end_dts);

                break;
            }
            if (cursor->m_Sample.IsSync()) {
                if (cursor->m_Sample.GetDts() >= cursor->m_EndDts) {
                    break; // done with this segment
                }
            }
        }
        if (Options.verbosity) {
            printf(" %d samples\n", sample_count);
        }
                
        // update moof and children
        trun->SetEntries(trun_entries);
        trun->SetDataOffset((AP4_UI32)moof->GetSize()+AP4_ATOM_HEADER_SIZE);
        
        // write moof
        moof->Write(output_stream);
        
        // write mdat
        output_stream.WriteUI32(mdat_size);
        output_stream.WriteUI32(AP4_ATOM_TYPE_MDAT);
        AP4_Sample     sample;
        AP4_DataBuffer sample_data;
        for (unsigned int i=0; i<sample_indexes.ItemCount(); i++) {
            result = cursor->m_Track->ReadSample(sample_indexes[i], sample, sample_data);
            if (AP4_FAILED(result)) {
                fprintf(stderr, "ERROR: failed to read sample %d (%d)\n", sample_indexes[i], result);
                return;
            }
            result = output_stream.Write(sample_data.GetData(), sample_data.GetDataSize());
            if (AP4_FAILED(result)) {
                fprintf(stderr, "ERROR: failed to write sample data (%d)\n", result);
                return;
            }
        }
        
        // cleanup
        delete moof;
    }
    
    // create an mfra container and write out the index
    AP4_ContainerAtom mfra(AP4_ATOM_TYPE_MFRA);
    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
        mfra.AddChild(cursors[i]->m_Tfra);
        cursors[i]->m_Tfra = NULL;
    }
    AP4_MfroAtom* mfro = new AP4_MfroAtom((AP4_UI32)mfra.GetSize()+16);
    mfra.AddChild(mfro);
    result = mfra.Write(output_stream);
    if (AP4_FAILED(result)) {
        fprintf(stderr, "ERROR: failed to write 'mfra' (%d)\n", result);
        return;
    }
    
    // cleanup
    for (unsigned int i=0; i<cursors.ItemCount(); i++) {
        delete cursors[i];
    }
    delete output_movie;
}