示例#1
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);
}
AP4_Result
AP4_Processor::NormalizeTRAF(AP4_ContainerAtom *atom, AP4_UI32 start, AP4_UI32 end, AP4_UI32 &index)
{
	for (; AP4_Atom* child = atom->GetChild(AP4_ATOM_TYPE_TRAF, index);) {
		AP4_TrafAtom* traf = AP4_DYNAMIC_CAST(AP4_TrafAtom, child);
		AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD));
		while (start < end && m_TrackData[start].original_id != tfhd->GetTrackId())
			;
		tfhd->SetTrackId(m_TrackData[start].new_id);
		traf->SetInternalTrackId(start);
		++index;
	}
	return AP4_SUCCESS;
}
/*----------------------------------------------------------------------
|   AP4_Processor::CreateFragmentHandler
+---------------------------------------------------------------------*/
AP4_Processor::FragmentHandler* 
AP4_Processor::CreateFragmentHandler(AP4_TrakAtom*      /* trak */,
                                     AP4_TrexAtom*      /* trex */,
                                     AP4_ContainerAtom* traf,
                                     AP4_ByteStream&    /* moof_data   */,
                                     AP4_Position       /* moof_offset */)
{
    // find the matching track handler
    for (unsigned int i=0; i<m_TrackData.ItemCount(); i++) {
        AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD));
        if (tfhd && m_TrackData[i].new_id == tfhd->GetTrackId()) {
			return new AP4_DefaultFragmentHandler(m_TrackData[i].track_handler);
        }
    }
    
    return NULL;
}
示例#4
0
文件: main.cpp 项目: xbmcin/XBMCinTC
  virtual AP4_Result ProcessMoof(AP4_ContainerAtom* moof,
    AP4_Position       moof_offset,
    AP4_Position       mdat_payload_offset)
  {
    AP4_Result result;

    if (!~m_Track->GetId())
    {
      AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, moof->FindChild("traf/tfhd"));
      m_Track->SetId(tfhd->GetTrackId());
    }

    if (m_Observer)
      m_Observer->BeginFragment(m_StreamId);

    if (AP4_SUCCEEDED((result = AP4_LinearReader::ProcessMoof(moof, moof_offset, mdat_payload_offset))) &&  m_Protected_desc)
    {
      //Setup the decryption
      AP4_CencSampleInfoTable *sample_table;
      AP4_UI32 algorithm_id = 0;

      delete m_Decrypter;
      m_Decrypter = 0;

      AP4_ContainerAtom *traf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, moof->GetChild(AP4_ATOM_TYPE_TRAF, 0));

      if (!m_Protected_desc || !traf)
        return AP4_ERROR_INVALID_FORMAT;

      if (AP4_FAILED(result = AP4_CencSampleInfoTable::Create(m_Protected_desc, traf, algorithm_id, *m_FragmentStream, moof_offset, sample_table)))
        return result;

      if (AP4_FAILED(result = AP4_CencSampleDecrypter::Create(sample_table, algorithm_id, 0, 0, 0, m_SingleSampleDecryptor, m_Decrypter)))
        return result;
    }
    if (m_Observer)
      m_Observer->EndFragment(m_StreamId);
    return result;
  }
示例#5
0
/*----------------------------------------------------------------------
|   main
+---------------------------------------------------------------------*/
int
main(int argc, char** argv)
{
    if (argc < 2) {
        PrintUsageAndExit();
    }
    
    // default options
    Options.verbose                = false;
    Options.input                  = NULL;
    Options.init_segment_name      = AP4_SPLIT_DEFAULT_INIT_SEGMENT_NAME;
    Options.media_segment_name     = AP4_SPLIT_DEFAULT_MEDIA_SEGMENT_NAME;
    Options.pattern_params         = AP4_SPLIT_DEFAULT_PATTERN_PARAMS;
    Options.start_number           = 1;
    Options.track_id               = 0;
    Options.audio_only             = false;
    Options.video_only             = false;
    Options.init_only              = false;
    Options.track_filter           = 0;
    
    // parse command line
    AP4_Result result;
    char** args = argv+1;
    while (const char* arg = *args++) {
        if (!strcmp(arg, "--verbose")) {
            Options.verbose = true;
        } else if (!strcmp(arg, "--init-segment")) {
            if (*args == NULL) {
                fprintf(stderr, "ERROR: missing argument after --init-segment option\n");
                return 1;
            }
            Options.init_segment_name = *args++;
        } else if (!strcmp(arg, "--media-segment")) {
            if (*args == NULL) {
                fprintf(stderr, "ERROR: missing argument after --media-segment option\n");
                return 1;
            }
            Options.media_segment_name = *args++;
        } else if (!strcmp(arg, "--pattern-parameters")) {
            if (*args == NULL) {
                fprintf(stderr, "ERROR: missing argument after --pattern-params option\n");
                return 1;
            }
            Options.pattern_params = *args++;
        } else if (!strcmp(arg, "--track-id")) {
            Options.track_id = strtoul(*args++, NULL, 10);
        } else if (!strcmp(arg, "--start-number")) {
            Options.start_number = strtoul(*args++, NULL, 10);
        } else if (!strcmp(arg, "--init-only")) {
            Options.init_only = true;
        } else if (!strcmp(arg, "--audio")) {
            Options.audio_only = true;
        } else if (!strcmp(arg, "--video")) {
            Options.video_only = true;
        } else if (Options.input == NULL) {
            Options.input = arg;
        } else {
            fprintf(stderr, "ERROR: unexpected argument\n");
            return 1;
        }
    }

    // check args
    if (Options.input == NULL) {
        fprintf(stderr, "ERROR: missing input file name\n");
        return 1;
    }
    if ((Options.audio_only && (Options.video_only || Options.track_id)) ||
        (Options.video_only && (Options.audio_only || Options.track_id)) ||
        (Options.track_id   && (Options.audio_only || Options.video_only))) {
        fprintf(stderr, "ERROR: --audio, --video and --track-id options are mutualy exclusive\n");
        return 1;
    }
    if (strlen(Options.pattern_params) < 1) {
        fprintf(stderr, "ERROR: --pattern-params argument is too short\n");
        return 1;
    }
    if (strlen(Options.pattern_params) > 2) {
        fprintf(stderr, "ERROR: --pattern-params argument is too long\n");
        return 1;
    }
    const char* cursor = Options.pattern_params;
    while (*cursor) {
        if (*cursor != 'I' && *cursor != 'N') {
            fprintf(stderr, "ERROR: invalid pattern parameter '%c'\n", *cursor);
            return 1;
        }
        ++cursor;
    }
    
	// create the input stream
    AP4_ByteStream* input = NULL;
    result = AP4_FileByteStream::Create(Options.input, AP4_FileByteStream::STREAM_MODE_READ, input);
    if (AP4_FAILED(result)) {
        fprintf(stderr, "ERROR: cannot open input (%d)\n", result);
        return 1;
    }
    
    // get the movie
    AP4_File* file = new AP4_File(*input, AP4_DefaultAtomFactory::Instance, true);
    AP4_Movie* movie = file->GetMovie();
    if (movie == NULL) {
        fprintf(stderr, "no movie found in file\n");
        return 1;
    }
    
    // filter tracks if required
    if (Options.audio_only) {
        AP4_Track* track = movie->GetTrack(AP4_Track::TYPE_AUDIO);
        if (track == NULL) {
            fprintf(stderr, "--audio option specified, but no audio track found\n");
            return 1;
        }
        Options.track_filter = track->GetId();
    } else if (Options.video_only) {
        AP4_Track* track = movie->GetTrack(AP4_Track::TYPE_VIDEO);
        if (track == NULL) {
            fprintf(stderr, "--video option specified, but no video track found\n");
            return 1;
        }
        Options.track_filter = track->GetId();
    } else if (Options.track_id) {
        AP4_Track* track = movie->GetTrack(Options.track_id);
        if (track == NULL) {
            fprintf(stderr, "--track-id option specified, but no such track found\n");
            return 1;
        }
        Options.track_filter = track->GetId();
    }
    
    // save the init segment
    AP4_ByteStream* output = NULL;
    result = AP4_FileByteStream::Create(Options.init_segment_name, AP4_FileByteStream::STREAM_MODE_WRITE, output);
    if (AP4_FAILED(result)) {
        fprintf(stderr, "ERROR: cannot open output file (%d)\n", result);
        return 1;
    }
    AP4_FtypAtom* ftyp = file->GetFileType(); 
    if (ftyp) {
        result = ftyp->Write(*output);
        if (AP4_FAILED(result)) {
            fprintf(stderr, "ERROR: cannot write ftyp segment (%d)\n", result);
            return 1;
        }
    }
    if (Options.track_filter) {
        AP4_MoovAtom* moov = movie->GetMoovAtom();
        
        // only keep the 'trak' atom that we need
        AP4_List<AP4_Atom>::Item* child = moov->GetChildren().FirstItem();
        while (child) {
            AP4_Atom* atom = child->GetData();
            child = child->GetNext();
            if (atom->GetType() == AP4_ATOM_TYPE_TRAK) {
                AP4_TrakAtom* trak = (AP4_TrakAtom*)atom;
                AP4_TkhdAtom* tkhd = (AP4_TkhdAtom*)trak->GetChild(AP4_ATOM_TYPE_TKHD);
                if (tkhd && tkhd->GetTrackId() != Options.track_filter) {
                    atom->Detach();
                    delete atom;
                }
            }
        }

        // only keep the 'trex' atom that we need
        AP4_ContainerAtom* mvex = AP4_DYNAMIC_CAST(AP4_ContainerAtom, moov->GetChild(AP4_ATOM_TYPE_MVEX));
        if (mvex) {
            child = mvex->GetChildren().FirstItem();
            while (child) {
                AP4_Atom* atom = child->GetData();
                child = child->GetNext();
                if (atom->GetType() == AP4_ATOM_TYPE_TREX) {
                    AP4_TrexAtom* trex = AP4_DYNAMIC_CAST(AP4_TrexAtom, atom);
                    if (trex && trex->GetTrackId() != Options.track_filter) {
                        atom->Detach();
                        delete atom;
                    }
                }
            }
        }
    }
    result = movie->GetMoovAtom()->Write(*output);
    if (AP4_FAILED(result)) {
        fprintf(stderr, "ERROR: cannot write init segment (%d)\n", result);
        return 1;
    }
        
    AP4_Atom* atom = NULL;
    unsigned int track_id = 0;
    for (;!Options.init_only;) {
        // process the next atom
        result = AP4_DefaultAtomFactory::Instance.CreateAtomFromStream(*input, atom);
        if (AP4_FAILED(result)) break;
        
        if (atom->GetType() == AP4_ATOM_TYPE_MOOF) {
            AP4_ContainerAtom* moof = AP4_DYNAMIC_CAST(AP4_ContainerAtom, atom);

            unsigned int traf_count = 0;
            AP4_ContainerAtom* traf = NULL;
            do {
                traf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, moof->GetChild(AP4_ATOM_TYPE_TRAF, traf_count));
                if (traf == NULL) break;
                AP4_TfhdAtom* tfhd = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD));
                if (tfhd == NULL) {
                    fprintf(stderr, "ERROR: invalid media format\n");
                    return 1;                    
                }
                track_id = tfhd->GetTrackId();
                traf_count++;
            } while (traf);
    
            // check if this fragment has more than one traf
            if (traf_count > 1) {
                if (Options.audio_only) {
                    fprintf(stderr, "ERROR: --audio option incompatible with multi-track fragments");
                    return 1;
                }
                if (Options.video_only) {
                    fprintf(stderr, "ERROR: --video option incompatible with multi-track fragments");
                    return 1;
                }
                track_id = 0;
            }
            
            // open a new file for this fragment
            if (output) {
                output->Release();
                output = NULL;
            }
            char segment_name[4096];
            if (Options.track_filter == 0 || Options.track_filter == track_id) {
                AP4_UI64 p[2] = {0,0};
                unsigned int params_len = strlen(Options.pattern_params);
                for (unsigned int i=0; i<params_len; i++) {
                    if (Options.pattern_params[i] == 'I') {
                        p[i] = track_id;
                    } else if (Options.pattern_params[i] == 'N') {
                        p[i] = NextFragmentIndex(track_id)+Options.start_number;
                    }
                }
                switch (params_len) {
                    case 1:
                        sprintf(segment_name, Options.media_segment_name, p[0]);
                        break;
                    case 2:
                        sprintf(segment_name, Options.media_segment_name, p[0], p[1]);
                        break;
                    default:
                        segment_name[0] = 0;
                        break;
                }
                result = AP4_FileByteStream::Create(segment_name, AP4_FileByteStream::STREAM_MODE_WRITE, output);
                if (AP4_FAILED(result)) {
                    fprintf(stderr, "ERROR: cannot open output file (%d)\n", result);
                    return 1;
                }
            }
        }
        
        // write the atom
        if (output && atom->GetType() != AP4_ATOM_TYPE_MFRA) {
            atom->Write(*output);
        }
        delete atom;
    }

    // cleanup
    delete file;
    if (input) input->Release();
    if (output) output->Release();
    
    return 0;
}
示例#6
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);
								}
							}
						}
					}
				}
			}
		}
	}
}
/*----------------------------------------------------------------------
|   AP4_Processor::ProcessFragments
+---------------------------------------------------------------------*/
AP4_Result
AP4_Processor::ProcessFragments(AP4_MoovAtom*              moov, 
                                AP4_List<AP4_MoofLocator>& moofs, 
                                AP4_ContainerAtom*         mfra,
                                AP4_ByteStream&            input, 
                                AP4_ByteStream&            output)
{
    // FIXME: this only works for non-changing moofs 
 
    for (AP4_List<AP4_MoofLocator>::Item* item = moofs.FirstItem();
                                          item;
                                          item = item->GetNext()) {
        AP4_MoofLocator*   locator     = item->GetData();
        AP4_ContainerAtom* moof        = locator->m_Moof;
        AP4_UI64           moof_offset = locator->m_Offset;
        AP4_UI64           mdat_payload_offset = moof_offset+moof->GetSize()+8;
        AP4_MovieFragment* fragment    = new AP4_MovieFragment(moof);
        AP4_Sample         sample;
        AP4_DataBuffer     sample_data_in;
        AP4_DataBuffer     sample_data_out;
        AP4_Result         result;
    
        // process all the traf atoms
        AP4_Array<AP4_Processor::FragmentHandler*> handlers;
        for (;AP4_Atom* atom = moof->GetChild(AP4_ATOM_TYPE_TRAF, handlers.ItemCount());) {
            AP4_ContainerAtom* traf = AP4_DYNAMIC_CAST(AP4_ContainerAtom, atom);
            AP4_Processor::FragmentHandler* handler = CreateFragmentHandler(traf);
            if (handler) result = handler->ProcessFragment();
            handlers.Append(handler);
        }
             
        // write the moof
        AP4_UI64 moof_out_start = 0;
        output.Tell(moof_out_start);
        bool moof_has_changed = false;
        moof->Write(output);
            
        // process all track runs
        for (unsigned int i=0; i<handlers.ItemCount(); i++) {
            AP4_FragmentSampleTable* sample_table = NULL;
            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));
            AP4_TfhdAtom* tfhd      = AP4_DYNAMIC_CAST(AP4_TfhdAtom, traf->GetChild(AP4_ATOM_TYPE_TFHD, i));
            
            // create a sample table object so we can read the sample data
            result = fragment->CreateSampleTable(moov, tfhd->GetTrackId(), &input, moof_offset, mdat_payload_offset, sample_table);
            if (AP4_FAILED(result)) return result;

            // compute the mdat size
            AP4_UI64 mdat_size = 0;
            for (unsigned int j=0; j<sample_table->GetSampleCount(); j++) {
                result = sample_table->GetSample(j, sample);
                if (AP4_FAILED(result)) return result;
                mdat_size += sample.GetSize();
            }
            
            // write an mdat header
            if (mdat_size > 0xFFFFFFFF-8) {
                // we don't support large mdat fragments
                return AP4_ERROR_OUT_OF_RANGE;
            }
            if (mdat_size) {
                output.WriteUI32((AP4_UI32)(8+mdat_size));
                output.WriteUI32(AP4_ATOM_TYPE_MDAT);
            }
            
#if defined(AP4_DEBUG)
            AP4_Position before;
            output.Tell(before);
#endif
            
            // write the mdat
            for (unsigned int j=0; j<sample_table->GetSampleCount(); j++) {
                result = sample_table->GetSample(j, sample);
                if (AP4_FAILED(result)) return result;
                sample.ReadData(sample_data_in);
                
                // 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;

                    // give the handler a chance to update the atoms
                    result = handler->FinishFragment();
                    if (AP4_SUCCEEDED(result)) moof_has_changed = true;
                } else {
                    // write the sample data (unmodified)
                    result = output.Write(sample_data_in.GetData(), sample_data_in.GetDataSize());
                    if (AP4_FAILED(result)) return result;
                }
            }
            
#if defined(AP4_DEBUG)
            AP4_Position after;
            output.Tell(after);
            AP4_ASSERT(after-before == mdat_size);
#endif
            delete sample_table;
        }
        
        // update the moof if needed
        AP4_UI64 mdat_out_end = 0;
        output.Tell(mdat_out_end);
        if (moof_has_changed) {
            output.Seek(moof_out_start);
            moof->Write(output);
            output.Seek(mdat_out_end);
        }
                
        // update the mfra if we have one
        if (mfra) {
            for (AP4_List<AP4_Atom>::Item* mfra_item = mfra->GetChildren().FirstItem();
                                           mfra_item;
                                           mfra_item = mfra_item->GetNext()) {
                if (mfra_item->GetData()->GetType() != AP4_ATOM_TYPE_TFRA) continue;
                AP4_TfraAtom* tfra = AP4_DYNAMIC_CAST(AP4_TfraAtom, mfra_item->GetData());
                if (tfra == NULL) continue;
                AP4_Array<AP4_TfraAtom::Entry>& entries     = tfra->GetEntries();
                AP4_Cardinal                    entry_count = entries.ItemCount();
                for (unsigned int i=0; i<entry_count; i++) {
                    if (entries[i].m_MoofOffset == locator->m_Offset) {
                        entries[i].m_MoofOffset = moof_out_start;
                    }
                }
            }
        }

        delete fragment;
    }
        
    return AP4_SUCCESS;
}