scummvm/audio/decoders/adpcm.cpp
2013-04-20 15:18:09 -04:00

461 lines
13 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 "common/stream.h"
#include "common/textconsole.h"
#include "common/util.h"
#include "audio/decoders/adpcm.h"
#include "audio/decoders/adpcm_intern.h"
namespace Audio {
// Routines to convert 12 bit linear samples to the
// Dialogic or Oki ADPCM coding format aka VOX.
// See also <http://www.comptek.ru/telephony/tnotes/tt1-13.html>
//
// IMA ADPCM support is based on
// <http://wiki.multimedia.cx/index.php?title=IMA_ADPCM>
//
// In addition, also MS IMA ADPCM is supported. See
// <http://wiki.multimedia.cx/index.php?title=Microsoft_IMA_ADPCM>.
ADPCMStream::ADPCMStream(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse, uint32 size, int rate, int channels, uint32 blockAlign)
: _stream(stream, disposeAfterUse),
_startpos(stream->pos()),
_endpos(_startpos + size),
_channels(channels),
_blockAlign(blockAlign),
_rate(rate) {
reset();
}
void ADPCMStream::reset() {
memset(&_status, 0, sizeof(_status));
_blockPos[0] = _blockPos[1] = _blockAlign; // To make sure first header is read
}
bool ADPCMStream::rewind() {
// TODO: Error checking.
reset();
_stream->seek(_startpos);
return true;
}
#pragma mark -
int Oki_ADPCMStream::readBuffer(int16 *buffer, const int numSamples) {
int samples;
byte data;
for (samples = 0; samples < numSamples && !endOfData(); samples++) {
if (_decodedSampleCount == 0) {
data = _stream->readByte();
_decodedSamples[0] = decodeOKI((data >> 4) & 0x0f);
_decodedSamples[1] = decodeOKI((data >> 0) & 0x0f);
_decodedSampleCount = 2;
}
// (1 - (count - 1)) ensures that _decodedSamples acts as a FIFO of depth 2
buffer[samples] = _decodedSamples[1 - (_decodedSampleCount - 1)];
_decodedSampleCount--;
}
return samples;
}
static const int16 okiStepSize[49] = {
16, 17, 19, 21, 23, 25, 28, 31,
34, 37, 41, 45, 50, 55, 60, 66,
73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658,
724, 796, 876, 963, 1060, 1166, 1282, 1411,
1552
};
// Decode Linear to ADPCM
int16 Oki_ADPCMStream::decodeOKI(byte code) {
int16 diff, E, samp;
E = (2 * (code & 0x7) + 1) * okiStepSize[_status.ima_ch[0].stepIndex] / 8;
diff = (code & 0x08) ? -E : E;
samp = _status.ima_ch[0].last + diff;
// Clip the values to +/- 2^11 (supposed to be 12 bits)
samp = CLIP<int16>(samp, -2048, 2047);
_status.ima_ch[0].last = samp;
_status.ima_ch[0].stepIndex += _stepAdjustTable[code];
_status.ima_ch[0].stepIndex = CLIP<int32>(_status.ima_ch[0].stepIndex, 0, ARRAYSIZE(okiStepSize) - 1);
// * 16 effectively converts 12-bit input to 16-bit output
return samp * 16;
}
#pragma mark -
int DVI_ADPCMStream::readBuffer(int16 *buffer, const int numSamples) {
int samples;
byte data;
for (samples = 0; samples < numSamples && !endOfData(); samples++) {
if (_decodedSampleCount == 0) {
data = _stream->readByte();
_decodedSamples[0] = decodeIMA((data >> 4) & 0x0f, 0);
_decodedSamples[1] = decodeIMA((data >> 0) & 0x0f, _channels == 2 ? 1 : 0);
_decodedSampleCount = 2;
}
// (1 - (count - 1)) ensures that _decodedSamples acts as a FIFO of depth 2
buffer[samples] = _decodedSamples[1 - (_decodedSampleCount - 1)];
_decodedSampleCount--;
}
return samples;
}
#pragma mark -
int Apple_ADPCMStream::readBuffer(int16 *buffer, const int numSamples) {
// Need to write at least one samples per channel
assert((numSamples % _channels) == 0);
// Current sample positions
int samples[2] = { 0, 0};
// Number of samples per channel
int chanSamples = numSamples / _channels;
for (int i = 0; i < _channels; i++) {
_stream->seek(_streamPos[i]);
while ((samples[i] < chanSamples) &&
// Last byte read and a new one needed
!((_stream->eos() || (_stream->pos() >= _endpos)) && (_chunkPos[i] == 0))) {
if (_blockPos[i] == _blockAlign) {
// 2 byte header per block
uint16 temp = _stream->readUint16BE();
// First 9 bits are the upper bits of the predictor
_status.ima_ch[i].last = (int16) (temp & 0xFF80);
// Lower 7 bits are the step index
_status.ima_ch[i].stepIndex = temp & 0x007F;
// Clip the step index
_status.ima_ch[i].stepIndex = CLIP<int32>(_status.ima_ch[i].stepIndex, 0, 88);
_blockPos[i] = 2;
}
if (_chunkPos[i] == 0) {
// Decode data
byte data = _stream->readByte();
_buffer[i][0] = decodeIMA(data & 0x0F, i);
_buffer[i][1] = decodeIMA(data >> 4, i);
}
// The original is interleaved block-wise, we want it sample-wise
buffer[_channels * samples[i] + i] = _buffer[i][_chunkPos[i]];
if (++_chunkPos[i] > 1) {
// We're about to decode the next byte, so advance the block position
_chunkPos[i] = 0;
_blockPos[i]++;
}
samples[i]++;
if (_channels == 2)
if (_blockPos[i] == _blockAlign)
// We're at the end of the block.
// Since the channels are interleaved, skip the next block
_stream->skip(MIN<uint32>(_blockAlign, _endpos - _stream->pos()));
_streamPos[i] = _stream->pos();
}
}
return samples[0] + samples[1];
}
#pragma mark -
int MSIma_ADPCMStream::readBuffer(int16 *buffer, const int numSamples) {
// Need to write at least one sample per channel
assert((numSamples % _channels) == 0);
int samples = 0;
while (samples < numSamples && !_stream->eos() && _stream->pos() < _endpos) {
if (_blockPos[0] == _blockAlign) {
for (int i = 0; i < _channels; i++) {
// read block header
_status.ima_ch[i].last = _stream->readSint16LE();
_status.ima_ch[i].stepIndex = _stream->readSint16LE();
}
_blockPos[0] = _channels * 4;
}
// Decode a set of samples
for (int i = 0; i < _channels; i++) {
// The stream encodes four bytes per channel at a time
for (int j = 0; j < 4; j++) {
byte data = _stream->readByte();
_blockPos[0]++;
_buffer[i][j * 2] = decodeIMA(data & 0x0f, i);
_buffer[i][j * 2 + 1] = decodeIMA((data >> 4) & 0x0f, i);
_samplesLeft[i] += 2;
}
}
while (samples < numSamples && _samplesLeft[0] != 0) {
for (int i = 0; i < _channels; i++) {
buffer[samples + i] = _buffer[i][8 - _samplesLeft[i]];
_samplesLeft[i]--;
}
samples += _channels;
}
}
return samples;
}
#pragma mark -
static const int MSADPCMAdaptCoeff1[] = {
256, 512, 0, 192, 240, 460, 392
};
static const int MSADPCMAdaptCoeff2[] = {
0, -256, 0, 64, 0, -208, -232
};
static const int MSADPCMAdaptationTable[] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
};
int16 MS_ADPCMStream::decodeMS(ADPCMChannelStatus *c, byte code) {
int32 predictor;
predictor = (((c->sample1) * (c->coeff1)) + ((c->sample2) * (c->coeff2))) / 256;
predictor += (signed)((code & 0x08) ? (code - 0x10) : (code)) * c->delta;
predictor = CLIP<int32>(predictor, -32768, 32767);
c->sample2 = c->sample1;
c->sample1 = predictor;
c->delta = (MSADPCMAdaptationTable[(int)code] * c->delta) >> 8;
if (c->delta < 16)
c->delta = 16;
return (int16)predictor;
}
int MS_ADPCMStream::readBuffer(int16 *buffer, const int numSamples) {
int samples;
byte data;
int i;
for (samples = 0; samples < numSamples && !endOfData(); samples++) {
if (_decodedSampleCount == 0) {
if (_blockPos[0] == _blockAlign) {
// read block header
for (i = 0; i < _channels; i++) {
_status.ch[i].predictor = CLIP(_stream->readByte(), (byte)0, (byte)6);
_status.ch[i].coeff1 = MSADPCMAdaptCoeff1[_status.ch[i].predictor];
_status.ch[i].coeff2 = MSADPCMAdaptCoeff2[_status.ch[i].predictor];
}
for (i = 0; i < _channels; i++)
_status.ch[i].delta = _stream->readSint16LE();
for (i = 0; i < _channels; i++)
_status.ch[i].sample1 = _stream->readSint16LE();
for (i = 0; i < _channels; i++)
_decodedSamples[_decodedSampleCount++] = _status.ch[i].sample2 = _stream->readSint16LE();
for (i = 0; i < _channels; i++)
_decodedSamples[_decodedSampleCount++] = _status.ch[i].sample1;
_blockPos[0] = _channels * 7;
} else {
data = _stream->readByte();
_blockPos[0]++;
_decodedSamples[_decodedSampleCount++] = decodeMS(&_status.ch[0], (data >> 4) & 0x0f);
_decodedSamples[_decodedSampleCount++] = decodeMS(&_status.ch[_channels - 1], data & 0x0f);
}
}
// (1 - (count - 1)) ensures that _decodedSamples acts as a FIFO of depth 2
buffer[samples] = _decodedSamples[1 - (_decodedSampleCount - 1)];
_decodedSampleCount--;
}
return samples;
}
#pragma mark -
#define DK3_READ_NIBBLE() \
do { \
if (_topNibble) { \
_nibble = _lastByte >> 4; \
_topNibble = false; \
} else { \
if (_stream->pos() >= _endpos) \
break; \
if ((_stream->pos() % _blockAlign) == 0) \
continue; \
_lastByte = _stream->readByte(); \
_nibble = _lastByte & 0xf; \
_topNibble = true; \
} \
} while (0)
int DK3_ADPCMStream::readBuffer(int16 *buffer, const int numSamples) {
int samples = 0;
assert((numSamples % 4) == 0);
while (samples < numSamples && !_stream->eos() && _stream->pos() < _endpos) {
if ((_stream->pos() % _blockAlign) == 0) {
_stream->readUint16LE(); // Unknown
uint16 rate = _stream->readUint16LE(); // Copy of rate
_stream->skip(6); // Unknown
// Get predictor for both sum/diff channels
_status.ima_ch[0].last = _stream->readSint16LE();
_status.ima_ch[1].last = _stream->readSint16LE();
// Get index for both sum/diff channels
_status.ima_ch[0].stepIndex = _stream->readByte();
_status.ima_ch[1].stepIndex = _stream->readByte();
if (_stream->eos())
break;
// Sanity check
assert(rate == getRate());
}
DK3_READ_NIBBLE();
decodeIMA(_nibble, 0);
DK3_READ_NIBBLE();
decodeIMA(_nibble, 1);
buffer[samples++] = _status.ima_ch[0].last + _status.ima_ch[1].last;
buffer[samples++] = _status.ima_ch[0].last - _status.ima_ch[1].last;
DK3_READ_NIBBLE();
decodeIMA(_nibble, 0);
buffer[samples++] = _status.ima_ch[0].last + _status.ima_ch[1].last;
buffer[samples++] = _status.ima_ch[0].last - _status.ima_ch[1].last;
}
return samples;
}
#pragma mark -
// This table is used to adjust the step for use on the next sample.
// We could half the table, but since the lookup index used is always
// a 4-bit nibble, it's more efficient to just keep it as it is.
const int16 ADPCMStream::_stepAdjustTable[16] = {
-1, -1, -1, -1, 2, 4, 6, 8,
-1, -1, -1, -1, 2, 4, 6, 8
};
const int16 Ima_ADPCMStream::_imaTable[89] = {
7, 8, 9, 10, 11, 12, 13, 14,
16, 17, 19, 21, 23, 25, 28, 31,
34, 37, 41, 45, 50, 55, 60, 66,
73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658,
724, 796, 876, 963, 1060, 1166, 1282, 1411,
1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024,
3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484,
7132, 7845, 8630, 9493,10442,11487,12635,13899,
15289,16818,18500,20350,22385,24623,27086,29794,
32767
};
int16 Ima_ADPCMStream::decodeIMA(byte code, int channel) {
int32 E = (2 * (code & 0x7) + 1) * _imaTable[_status.ima_ch[channel].stepIndex] / 8;
int32 diff = (code & 0x08) ? -E : E;
int32 samp = CLIP<int32>(_status.ima_ch[channel].last + diff, -32768, 32767);
_status.ima_ch[channel].last = samp;
_status.ima_ch[channel].stepIndex += _stepAdjustTable[code];
_status.ima_ch[channel].stepIndex = CLIP<int32>(_status.ima_ch[channel].stepIndex, 0, ARRAYSIZE(_imaTable) - 1);
return samp;
}
RewindableAudioStream *makeADPCMStream(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse, uint32 size, ADPCMType type, int rate, int channels, uint32 blockAlign) {
// If size is 0, report the entire size of the stream
if (!size)
size = stream->size();
switch (type) {
case kADPCMOki:
return new Oki_ADPCMStream(stream, disposeAfterUse, size, rate, channels, blockAlign);
case kADPCMMSIma:
return new MSIma_ADPCMStream(stream, disposeAfterUse, size, rate, channels, blockAlign);
case kADPCMMS:
return new MS_ADPCMStream(stream, disposeAfterUse, size, rate, channels, blockAlign);
case kADPCMDVI:
return new DVI_ADPCMStream(stream, disposeAfterUse, size, rate, channels, blockAlign);
case kADPCMApple:
return new Apple_ADPCMStream(stream, disposeAfterUse, size, rate, channels, blockAlign);
case kADPCMDK3:
return new DK3_ADPCMStream(stream, disposeAfterUse, size, rate, channels, blockAlign);
default:
error("Unsupported ADPCM encoding");
break;
}
}
} // End of namespace Audio