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VIDEO: Use the standalone AC-3 decoder in the MPEG-PS code

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This code comes from clone2727's now defunct (?) ac3 branch, with
some minor compile fixes. This represents the latest version of
the stalled AC-3 decoder work for Zork: Grand Inquisitor. Note,
however, that I have not yet asked for clone2727's permission to
use this. I'm just experimenting.
This commit is contained in:
Torbjörn Andersson 2018-05-11 14:03:19 +02:00 • committed by Thierry Crozat
parent 6705b6df9e
commit 43b29a93d7
2 changed files with 15 additions and 136 deletions
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133
video/mpegps_decoder.cpp
View file

@ -21,6 +21,7 @@
*/
#include "audio/audiostream.h"
#include "audio/decoders/ac3.h"
#include "audio/decoders/mp3.h"
#include "common/debug.h"
#include "common/endian.h"
@ -118,7 +119,7 @@ void MPEGPSDecoder::readNextPacket() {
#ifdef USE_A52
handled = true;
AC3AudioTrack *ac3Track = new AC3AudioTrack(packet);
AC3AudioTrack *ac3Track = new AC3AudioTrack(*packet, getSoundType());
stream = ac3Track;
_streamMap[startCode] = ac3Track;
addTrack(ac3Track);
@ -545,35 +546,24 @@ Audio::AudioStream *MPEGPSDecoder::MPEGAudioTrack::getAudioStream() const {
#ifdef USE_A52
MPEGPSDecoder::AC3AudioTrack::AC3AudioTrack(Common::SeekableReadStream *firstPacket) {
// 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);
initStream(firstPacket);
if (_sampleRate >= 0) {
_audStream = Audio::makeQueuingAudioStream(_sampleRate, true);
} else {
_audStream = 0;
}
firstPacket->seek(0);
_inBufPtr = _inBuf;
_flags = 0;
_frameSize = 0;
MPEGPSDecoder::AC3AudioTrack::AC3AudioTrack(Common::SeekableReadStream &firstPacket, Audio::Mixer::SoundType soundType) :
AudioTrack(soundType) {
_audStream = Audio::makeAC3Stream(firstPacket);
if (!_audStream)
error("Could not create AC-3 stream");
}
MPEGPSDecoder::AC3AudioTrack::~AC3AudioTrack() {
delete _audStream;
a52_free(_a52State);
}
bool MPEGPSDecoder::AC3AudioTrack::sendPacket(Common::SeekableReadStream *packet, uint32 pts, uint32 dts) {
if (_audStream) {
decodeAC3Data(packet);
}
delete packet;
// Skip DVD code
packet->readUint32LE();
if (packet->eos())
return true;
_audStream->queuePacket(packet);
return true;
}
@ -581,103 +571,6 @@ Audio::AudioStream *MPEGPSDecoder::AC3AudioTrack::getAudioStream() const {
return _audStream;
}
enum {
HEADER_SIZE = 7
};
void MPEGPSDecoder::AC3AudioTrack::initStream(Common::SeekableReadStream *packet) {
byte buf[HEADER_SIZE];
_sampleRate = -1;
// Probably not very efficient, but hopefully we never do more than a
// few iterations of this loop.
for (uint i = 0; i < packet->size() - sizeof(buf); i++) {
int flags, bitRate;
packet->seek(i, SEEK_SET);
packet->read(buf, sizeof(buf));
if (a52_syncinfo(buf, &flags, &_sampleRate, &bitRate) > 0) {
break;
}
}
}
void MPEGPSDecoder::AC3AudioTrack::decodeAC3Data(Common::SeekableReadStream *packet) {
// Skip the DVD code
packet->readUint32LE();
if (packet->eos())
return;
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 {
int flags = A52_STEREO | A52_ADJUST_LEVEL;
sample_t level = 32767;
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)samples[j];
*outputPtr++ = (int16)samples[j + 256];
}
outputLength += 1024;
}
}
if (outputLength > 0) {
flags = Audio::FLAG_STEREO | Audio::FLAG_16BITS;
#ifdef SCUMM_LITTLE_ENDIAN
flags |= Audio::FLAG_LITTLE_ENDIAN;
#endif
_audStream->queueBuffer((byte *)outputBuffer, outputLength, DisposeAfterUse::YES, flags);
}
_inBufPtr = _inBuf;
_frameSize = 0;
}
}
}
#endif
} // End of namespace Video

18
video/mpegps_decoder.h
View file

@ -28,11 +28,6 @@
#include "graphics/surface.h"
#include "video/video_decoder.h"
#ifdef USE_A52
extern "C" {
#include <a52dec/a52.h>
}
namespace Audio {
class PacketizedAudioStream;
}
@ -136,7 +131,7 @@ private:
#ifdef USE_A52
class AC3AudioTrack : public AudioTrack, public MPEGStream {
public:
AC3AudioTrack(Common::SeekableReadStream *firstPacket);
AC3AudioTrack(Common::SeekableReadStream &firstPacket, Audio::Mixer::SoundType soundType);
~AC3AudioTrack();
bool sendPacket(Common::SeekableReadStream *packet, uint32 pts, uint32 dts);
@ -146,16 +141,7 @@ private:
Audio::AudioStream *getAudioStream() const;
private:
Audio::QueuingAudioStream *_audStream;
a52_state_t *_a52State;
uint32 _frameSize;
byte _inBuf[4096];
byte *_inBufPtr;
int _flags;
int _sampleRate;
void initStream(Common::SeekableReadStream *packet);
void decodeAC3Data(Common::SeekableReadStream *packet);
Audio::PacketizedAudioStream *_audStream;
};
#endif