scummvm/audio/decoders/aac.cpp
2011-08-06 11:30:47 +01:00

131 lines
3.9 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "audio/decoders/aac.h"
#ifdef USE_FAAD
#include "common/debug.h"
#include "common/memstream.h"
#include "common/stream.h"
#include "common/textconsole.h"
#include "common/util.h"
#include "audio/audiostream.h"
#include "audio/decoders/codec.h"
#include "audio/decoders/raw.h"
#include <neaacdec.h>
namespace Audio {
class AACDecoder : public Codec {
public:
AACDecoder(Common::SeekableReadStream *extraData,
DisposeAfterUse::Flag disposeExtraData);
~AACDecoder();
AudioStream *decodeFrame(Common::SeekableReadStream &stream);
private:
NeAACDecHandle _handle;
byte _channels;
unsigned long _rate;
};
AACDecoder::AACDecoder(Common::SeekableReadStream *extraData, DisposeAfterUse::Flag disposeExtraData) {
// Open the library
_handle = NeAACDecOpen();
// Configure the library to our needs
NeAACDecConfigurationPtr conf = NeAACDecGetCurrentConfiguration(_handle);
conf->outputFormat = FAAD_FMT_16BIT; // We only support 16bit audio
conf->downMatrix = 1; // Convert from 5.1 to stereo if required
NeAACDecSetConfiguration(_handle, conf);
// Copy the extra data to a buffer
extraData->seek(0);
byte *extraDataBuf = new byte[extraData->size()];
extraData->read(extraDataBuf, extraData->size());
// Initialize with our extra data
// NOTE: This code assumes the extra data is coming from an MPEG-4 file!
int err = NeAACDecInit2(_handle, extraDataBuf, extraData->size(), &_rate, &_channels);
delete[] extraDataBuf;
if (err < 0)
error("Could not initialize AAC decoder: %s", NeAACDecGetErrorMessage(err));
if (disposeExtraData == DisposeAfterUse::YES)
delete extraData;
}
AACDecoder::~AACDecoder() {
NeAACDecClose(_handle);
}
AudioStream *AACDecoder::decodeFrame(Common::SeekableReadStream &stream) {
// read everything into a buffer
uint32 inBufferPos = 0;
uint32 inBufferSize = stream.size();
byte *inBuffer = new byte[inBufferSize];
stream.read(inBuffer, inBufferSize);
QueuingAudioStream *audioStream = makeQueuingAudioStream(_rate, _channels == 2);
// Decode until we have enough samples (or there's no more left)
while (inBufferPos < inBufferSize) {
NeAACDecFrameInfo frameInfo;
void *decodedSamples = NeAACDecDecode(_handle, &frameInfo, inBuffer + inBufferPos, inBufferSize - inBufferPos);
if (frameInfo.error != 0)
error("Failed to decode AAC frame: %s", NeAACDecGetErrorMessage(frameInfo.error));
byte *buffer = (byte *)malloc(frameInfo.samples * 2);
memcpy(buffer, decodedSamples, frameInfo.samples * 2);
byte flags = FLAG_16BITS;
if (_channels == 2)
flags |= FLAG_STEREO;
#ifdef SCUMM_LITTLE_ENDIAN
flags |= FLAG_LITTLE_ENDIAN;
#endif
audioStream->queueBuffer(buffer, frameInfo.samples * 2, DisposeAfterUse::YES, flags);
inBufferPos += frameInfo.bytesconsumed;
}
return audioStream;
}
// Factory function
Codec *makeAACDecoder(Common::SeekableReadStream *extraData, DisposeAfterUse::Flag disposeExtraData) {
return new AACDecoder(extraData, disposeExtraData);
}
} // End of namespace Audio
#endif // #ifdef USE_FAAD