scummvm/engines/kyra/sound_digital.cpp
Johannes Schickel 287e79d477 Documenting the sound code a bit.
svn-id: r29392
2007-11-03 23:32:15 +00:00

390 lines
8.9 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.
*
* $URL$
* $Id$
*
*/
#include "kyra/sound.h"
#include "sound/audiostream.h"
namespace Kyra {
// Thanks to Torbjorn Andersson (eriktorbjorn) for his aud player on which
// this code is based on
// TODO: cleanup of whole AUDStream
class AUDStream : public Audio::AudioStream {
public:
AUDStream(Common::File *file, bool loop = false);
~AUDStream();
int readBuffer(int16 *buffer, const int numSamples);
bool isStereo() const { return false; }
bool endOfData() const { return _endOfData; }
int getRate() const { return _rate; }
void beginFadeIn();
void beginFadeOut();
private:
Common::File *_file;
bool _loop;
uint32 _loopStart;
bool _endOfData;
int _rate;
uint _processedSize;
uint _totalSize;
int _bytesLeft;
byte *_outBuffer;
int _outBufferOffset;
uint _outBufferSize;
byte *_inBuffer;
uint _inBufferSize;
int32 _fadeSamples;
int32 _fadeCount;
int _fading;
int readChunk(int16 *buffer, const int maxSamples);
static const int8 WSTable2Bit[];
static const int8 WSTable4Bit[];
};
const int8 AUDStream::WSTable2Bit[] = { -2, -1, 0, 1 };
const int8 AUDStream::WSTable4Bit[] = {
-9, -8, -6, -5, -4, -3, -2, -1,
0, 1, 2, 3, 4, 5, 6, 8
};
AUDStream::AUDStream(Common::File *file, bool loop) : _file(file), _endOfData(true), _rate(0),
_processedSize(0), _totalSize(0), _bytesLeft(0), _outBuffer(0),
_outBufferOffset(0), _outBufferSize(0), _inBuffer(0), _inBufferSize(0) {
_rate = _file->readUint16LE();
_totalSize = _file->readUint32LE();
_loop = loop;
// TODO: Find the correct number of samples for a fade-in/out. Should
// probably take the same amount of time as a palette fade.
_fadeSamples = 2 * getRate();
_fading = 0;
// TODO?: add checks
int flags = _file->readByte(); // flags
int type = _file->readByte(); // type
_loopStart = file->pos();
if (type == 1 && !flags) {
_endOfData = false;
} else
warning("No AUD file (rate: %d, size: %d, flags: 0x%X, type: %d)", _rate, _totalSize, flags, type);
}
AUDStream::~AUDStream() {
delete [] _outBuffer;
delete [] _inBuffer;
delete _file;
}
void AUDStream::beginFadeIn() {
if (_fading == 0)
_fadeCount = 0;
_fading = 1;
}
void AUDStream::beginFadeOut() {
if (_fading == 0)
_fadeCount = _fadeSamples;
_fading = -1;
}
int AUDStream::readBuffer(int16 *buffer, const int numSamples) {
int samplesRead = 0, samplesLeft = numSamples;
while (samplesLeft > 0 && !_endOfData) {
int samples = readChunk(buffer, samplesLeft);
samplesRead += samples;
samplesLeft -= samples;
buffer += samples;
}
return samplesRead;
}
inline int16 clip8BitSample(int16 sample) {
if (sample > 255)
return 255;
if (sample < 0)
return 0;
return sample;
}
int AUDStream::readChunk(int16 *buffer, const int maxSamples) {
int samplesProcessed = 0;
// if no bytes of the old chunk are left, read the next one
if (_bytesLeft <= 0) {
if (_processedSize >= _totalSize) {
if (_loop) {
_file->seek(_loopStart);
_processedSize = 0;
} else {
_endOfData = true;
return 0;
}
}
uint16 size = _file->readUint16LE();
uint16 outSize = _file->readUint16LE();
uint32 id = _file->readUint32LE();
assert(id == 0x0000DEAF);
_processedSize += 8 + size;
_outBufferOffset = 0;
if (size == outSize) {
if (outSize > _outBufferSize) {
_outBufferSize = outSize;
delete [] _outBuffer;
_outBuffer = new uint8[_outBufferSize];
assert(_outBuffer);
}
_bytesLeft = size;
_file->read(_outBuffer, _bytesLeft);
} else {
_bytesLeft = outSize;
if (outSize > _outBufferSize) {
_outBufferSize = outSize;
delete [] _outBuffer;
_outBuffer = new uint8[_outBufferSize];
assert(_outBuffer);
}
if (size > _inBufferSize) {
_inBufferSize = size;
delete [] _inBuffer;
_inBuffer = new uint8[_inBufferSize];
assert(_inBuffer);
}
if (_file->read(_inBuffer, size) != size) {
_endOfData = true;
return 0;
}
int16 curSample = 0x80;
byte code = 0;
int8 count = 0;
uint16 input = 0;
int j = 0;
int i = 0;
while (outSize > 0) {
input = _inBuffer[i++] << 2;
code = (input >> 8) & 0xff;
count = (input & 0xff) >> 2;
switch (code) {
case 2:
if (count & 0x20) {
/* NOTE: count is signed! */
count <<= 3;
curSample += (count >> 3);
_outBuffer[j++] = curSample & 0xFF;
outSize--;
} else {
for (; count >= 0; count--) {
_outBuffer[j++] = _inBuffer[i++];
outSize--;
}
curSample = _inBuffer[i - 1];
}
break;
case 1:
for (; count >= 0; count--) {
code = _inBuffer[i++];
curSample += WSTable4Bit[code & 0x0f];
curSample = clip8BitSample(curSample);
_outBuffer[j++] = curSample;
curSample += WSTable4Bit[code >> 4];
curSample = clip8BitSample(curSample);
_outBuffer[j++] = curSample;
outSize -= 2;
}
break;
case 0:
for (; count >= 0; count--) {
code = (uint8)_inBuffer[i++];
curSample += WSTable2Bit[code & 0x03];
curSample = clip8BitSample(curSample);
_outBuffer[j++] = curSample & 0xFF;
curSample += WSTable2Bit[(code >> 2) & 0x03];
curSample = clip8BitSample(curSample);
_outBuffer[j++] = curSample & 0xFF;
curSample += WSTable2Bit[(code >> 4) & 0x03];
curSample = clip8BitSample(curSample);
_outBuffer[j++] = curSample & 0xFF;
curSample += WSTable2Bit[(code >> 6) & 0x03];
curSample = clip8BitSample(curSample);
_outBuffer[j++] = curSample & 0xFF;
outSize -= 4;
}
break;
default:
for (; count >= 0; count--) {
_outBuffer[j++] = curSample & 0xFF;
outSize--;
}
}
}
}
}
// copies the chunk data to the output buffer
if (_bytesLeft > 0) {
int samples = MIN(_bytesLeft, maxSamples);
samplesProcessed += samples;
_bytesLeft -= samples;
// To help avoid overflows for long fade times, we divide both
// _fadeSamples and _fadeCount when calculating the new sample.
int32 div = _fadeSamples / 256;
while (samples--) {
int16 sample = (_outBuffer[_outBufferOffset++] << 8) ^ 0x8000;
if (_fading) {
sample = (sample * (_fadeCount / 256)) / div;
_fadeCount += _fading;
if (_fadeCount < 0) {
_fadeCount = 0;
_endOfData = true;
} else if (_fadeCount > _fadeSamples) {
_fadeCount = _fadeSamples;
_fading = 0;
}
}
*buffer++ = sample;
}
}
if (_fading < 0 && _fadeCount == 0)
_fading = false;
return samplesProcessed;
}
#pragma mark -
SoundDigital::SoundDigital(KyraEngine *vm, Audio::Mixer *mixer) : _vm(vm), _mixer(mixer), _sounds() {
memset(_sounds, 0, sizeof(_sounds));
}
SoundDigital::~SoundDigital() {
for (int i = 0; i < SOUND_STREAMS; ++i)
stopSound(i);
}
int SoundDigital::playSound(Common::File *fileHandle, bool loop, bool fadeIn, int channel) {
Sound *use = 0;
if (channel != -1 && channel < SOUND_STREAMS) {
stopSound(channel);
use = &_sounds[channel];
} else {
for (channel = 0; channel < SOUND_STREAMS; ++channel) {
if (!_sounds[channel].stream) {
use = &_sounds[channel];
break;
}
}
if (!use) {
warning("no free sound channel");
delete fileHandle;
return -1;
}
}
use->stream = new AUDStream(fileHandle, loop);
if (use->stream->endOfData()) {
delete use->stream;
use->stream = 0;
return -1;
}
if (fadeIn)
use->stream->beginFadeIn();
// TODO: set correct sound type from channel id
_mixer->playInputStream(Audio::Mixer::kPlainSoundType, &use->handle, use->stream);
return use - _sounds;
}
bool SoundDigital::isPlaying(int channel) {
if (channel == -1)
return false;
assert(channel >= 0 && channel < SOUND_STREAMS);
return _mixer->isSoundHandleActive(_sounds[channel].handle);
}
void SoundDigital::stopSound(int channel) {
assert(channel >= 0 && channel < SOUND_STREAMS);
_mixer->stopHandle(_sounds[channel].handle);
_sounds[channel].stream = 0;
}
void SoundDigital::beginFadeOut(int channel) {
if (isPlaying(channel))
_sounds[channel].stream->beginFadeOut();
}
} // end of namespace Kyra