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/* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "common/ptr.h"
#include "common/stream.h"
#include "common/textconsole.h"
#include "common/util.h"
#include "audio/audiostream.h"
#include "audio/decoders/ac3.h"
#include "audio/decoders/raw.h"
extern "C" {
#include <a52dec/a52.h>
}
namespace Audio {
class AC3Stream : public PacketizedAudioStream {
public:
AC3Stream(double decibel);
~AC3Stream();
bool init(Common::SeekableReadStream &firstPacket);
void deinit();
// AudioStream API
int readBuffer(int16 *buffer, const int numSamples) override { return _audStream->readBuffer(buffer, numSamples); }
bool isStereo() const override { return _audStream->isStereo(); }
int getRate() const override { return _audStream->getRate(); }
bool endOfData() const override { return _audStream->endOfData(); }
bool endOfStream() const override { return _audStream->endOfStream(); }
// PacketizedAudioStream API
void queuePacket(Common::SeekableReadStream *data) override;
void finish() override { _audStream->finish(); }
private:
Common::ScopedPtr<QueuingAudioStream> _audStream;
a52_state_t *_a52State;
uint32 _frameSize;
byte _inBuf[4096];
byte *_inBufPtr;
int _flags;
int _sampleRate;
double _audioGain;
};
AC3Stream::AC3Stream(double decibel) : _a52State(nullptr), _frameSize(0), _inBufPtr(nullptr), _flags(0), _sampleRate(0) {
_audioGain = pow(2, decibel / 6);
}
AC3Stream::~AC3Stream() {
deinit();
}
enum {
HEADER_SIZE = 7
};
bool AC3Stream::init(Common::SeekableReadStream &firstPacket) {
deinit();
// In theory, I should pass mm_accel() to a52_init(), but I don't know
// where that's supposed to be defined.
_a52State = a52_init(0);
// Go through the header to find sync
byte buf[HEADER_SIZE];
_sampleRate = -1;
for (uint i = 0; i < firstPacket.size() - sizeof(buf); i++) {
int flags, bitRate;
firstPacket.seek(i);
firstPacket.read(buf, sizeof(buf));
if (a52_syncinfo(buf, &flags, &_sampleRate, &bitRate) > 0)
break;
}
// Ensure we have a valid sample rate
if (_sampleRate <= 0) {
deinit();
return false;
}
_audStream.reset(makeQueuingAudioStream(_sampleRate, true));
_inBufPtr = _inBuf;
_flags = 0;
_frameSize = 0;
return true;
}
void AC3Stream::deinit() {
if (!_a52State)
return;
_audStream.reset();
a52_free(_a52State);
_a52State = nullptr;
}
void AC3Stream::queuePacket(Common::SeekableReadStream *data) {
Common::ScopedPtr<Common::SeekableReadStream> packet(data);
while (packet->pos() < packet->size()) {
uint32 leftSize = packet->size() - packet->pos();
uint32 len = _inBufPtr - _inBuf;
if (_frameSize == 0) {
// No header seen: find one
len = HEADER_SIZE - len;
if (len > leftSize)
len = leftSize;
packet->read(_inBufPtr, len);
leftSize -= len;
_inBufPtr += len;
if ((_inBufPtr - _inBuf) == HEADER_SIZE) {
int sampleRate, bitRate;
len = a52_syncinfo(_inBuf, &_flags, &sampleRate, &bitRate);
if (len == 0) {
memmove(_inBuf, _inBuf + 1, HEADER_SIZE - 1);
_inBufPtr--;
} else {
_frameSize = len;
}
}
} else if (len < _frameSize) {
len = _frameSize - len;
if (len > leftSize)
len = leftSize;
assert(len < sizeof(_inBuf) - (_inBufPtr - _inBuf));
packet->read(_inBufPtr, len);
leftSize -= len;
_inBufPtr += len;
} else {
// TODO: Eventually support more than just stereo max
int flags = A52_STEREO | A52_ADJUST_LEVEL;
sample_t level = 32767 * _audioGain;
if (a52_frame(_a52State, _inBuf, &flags, &level, 0) != 0)
error("Frame fail");
int16 *outputBuffer = (int16 *)malloc(6 * 256 * 2 * 2);
int16 *outputPtr = outputBuffer;
int outputLength = 0;
for (int i = 0; i < 6; i++) {
if (a52_block(_a52State) == 0) {
sample_t *samples = a52_samples(_a52State);
for (int j = 0; j < 256; j++) {
*outputPtr++ = (int16)CLIP<sample_t>(samples[j], -32768, 32767);
*outputPtr++ = (int16)CLIP<sample_t>(samples[j + 256], -32768, 32767);
}
outputLength += 1024;
}
}
if (outputLength > 0) {
flags = FLAG_STEREO | FLAG_16BITS;
#ifdef SCUMM_LITTLE_ENDIAN
flags |= FLAG_LITTLE_ENDIAN;
#endif
_audStream->queueBuffer((byte *)outputBuffer, outputLength, DisposeAfterUse::YES, flags);
}
_inBufPtr = _inBuf;
_frameSize = 0;
}
}
}
PacketizedAudioStream *makeAC3Stream(Common::SeekableReadStream &firstPacket, double decibel) {
Common::ScopedPtr<AC3Stream> stream(new AC3Stream(decibel));
if (!stream->init(firstPacket))
return nullptr;
return stream.release();
}
} // End of namespace Audio
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