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|
/*****************************************************************
|
| AP4 - File Writer
|
| Copyright 2002-2008 Axiomatic Systems, LLC
|
|
| This file is part of Bento4/AP4 (MP4 Atom Processing Library).
|
| Unless you have obtained Bento4 under a difference license,
| this version of Bento4 is Bento4|GPL.
| Bento4|GPL is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2, or (at your option)
| any later version.
|
| Bento4|GPL is distributed in the hope that it will be useful,
| but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License
| along with Bento4|GPL; see the file COPYING. If not, write to the
| Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
| 02111-1307, USA.
|
****************************************************************/
/*----------------------------------------------------------------------
| includes
+---------------------------------------------------------------------*/
#include "Ap4MoovAtom.h"
#include "Ap4FileWriter.h"
#include "Ap4Movie.h"
#include "Ap4File.h"
#include "Ap4TrakAtom.h"
#include "Ap4Track.h"
#include "Ap4Sample.h"
#include "Ap4DataBuffer.h"
#include "Ap4FtypAtom.h"
#include "Ap4SampleTable.h"
/*----------------------------------------------------------------------
| AP4_FileWriter::Write
+---------------------------------------------------------------------*/
AP4_Result
AP4_FileWriter::Write(AP4_File& file, AP4_ByteStream& stream, Interleaving /* interleaving */)
{
// get the file type
AP4_FtypAtom* file_type = file.GetFileType();
// write the ftyp atom (always first)
if (file_type) file_type->Write(stream);
// write the top-level atoms, except for ftyp, moov and mdat
for (AP4_List<AP4_Atom>::Item* atom_item = file.GetChildren().FirstItem();
atom_item;
atom_item = atom_item->GetNext()) {
AP4_Atom* atom = atom_item->GetData();
if (atom->GetType() != AP4_ATOM_TYPE_MDAT &&
atom->GetType() != AP4_ATOM_TYPE_FTYP &&
atom->GetType() != AP4_ATOM_TYPE_MOOV) {
atom->Write(stream);
}
}
// get the movie object (and stop if there isn't any)
AP4_Movie* movie = file.GetMovie();
if (movie == NULL) return AP4_SUCCESS;
// see how much we've written so far
AP4_Position position;
stream.Tell(position);
// backup and recompute all the chunk offsets
unsigned int t=0;
AP4_Result result = AP4_SUCCESS;
AP4_UI64 mdat_size = AP4_ATOM_HEADER_SIZE;
AP4_UI64 mdat_position = position+movie->GetMoovAtom()->GetSize();
AP4_Array<AP4_Array<AP4_UI64>*> trak_chunk_offsets_backup;
AP4_Array<AP4_UI64> chunk_offsets;
for (AP4_List<AP4_Track>::Item* track_item = movie->GetTracks().FirstItem();
track_item;
track_item = track_item->GetNext()) {
AP4_Track* track = track_item->GetData();
AP4_TrakAtom* trak = track->UseTrakAtom();
// backup the chunk offsets
AP4_Array<AP4_UI64>* chunk_offsets_backup = new AP4_Array<AP4_UI64>();
trak_chunk_offsets_backup.Append(chunk_offsets_backup);
result = trak->GetChunkOffsets(*chunk_offsets_backup);
if (AP4_FAILED(result)) goto end;
// allocate space for the new chunk offsets
chunk_offsets.SetItemCount(chunk_offsets_backup->ItemCount());
// compute the new chunk offsets
AP4_Cardinal sample_count = track->GetSampleCount();
AP4_SampleTable* sample_table = track->GetSampleTable();
AP4_Sample sample;
for (AP4_Ordinal i=0; i<sample_count; i++) {
AP4_Ordinal chunk_index = 0;
AP4_Ordinal position_in_chunk = 0;
sample_table->GetSampleChunkPosition(i, chunk_index, position_in_chunk);
sample_table->GetSample(i, sample);
if (position_in_chunk == 0) {
// this sample is the first sample in a chunk, so this is the start of a chunk
if (chunk_index >= chunk_offsets.ItemCount()) return AP4_ERROR_INTERNAL;
chunk_offsets[chunk_index] = mdat_position+mdat_size;
}
mdat_size += sample.GetSize();
}
result = trak->SetChunkOffsets(chunk_offsets);
}
// write the moov atom
movie->GetMoovAtom()->Write(stream);
// create and write the media data (mdat)
// FIXME: this only supports 32-bit mdat size
stream.WriteUI32((AP4_UI32)mdat_size);
stream.WriteUI32(AP4_ATOM_TYPE_MDAT);
// write all tracks and restore the chunk offsets to their backed-up values
for (AP4_List<AP4_Track>::Item* track_item = movie->GetTracks().FirstItem();
track_item;
track_item = track_item->GetNext(), ++t) {
AP4_Track* track = track_item->GetData();
AP4_TrakAtom* trak = track->UseTrakAtom();
// restore the backed-up chunk offsets
result = trak->SetChunkOffsets(*trak_chunk_offsets_backup[t]);
// write all the track's samples
AP4_Cardinal sample_count = track->GetSampleCount();
AP4_Sample sample;
AP4_DataBuffer sample_data;
for (AP4_Ordinal i=0; i<sample_count; i++) {
track->ReadSample(i, sample, sample_data);
stream.Write(sample_data.GetData(), sample_data.GetDataSize());
}
}
end:
for (unsigned int i=0; i<trak_chunk_offsets_backup.ItemCount(); i++) {
delete trak_chunk_offsets_backup[i];
}
return result;
}
|
