scummvm/engines/saga/shorten.cpp

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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 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/scummsys.h"
#include "common/textconsole.h"
#include "saga/shorten.h"
#ifdef SOUND_SHORTEN_H
// Based on etree's Shorten tool, version 3.6.1
// http://etree.org/shnutils/shorten/
// FIXME: This doesn't work yet correctly
#include "common/util.h"
#include "audio/decoders/raw.h"
namespace Saga {
#define MASKTABSIZE 33
#define MAX_SUPPORTED_VERSION 3
#define DEFAULT_BLOCK_SIZE 256
enum kShortenTypes {
kTypeAU1 = 0, // lossless ulaw
kTypeS8 = 1, // signed 8 bit
kTypeU8 = 2, // unsigned 8 bit
kTypeS16HL = 3, // signed 16 bit shorts: high-low
kTypeU16HL = 4, // unsigned 16 bit shorts: high-low
kTypeS16LH = 5, // signed 16 bit shorts: low-high
kTypeU16LH = 6, // unsigned 16 bit shorts: low-high
kTypeULaw = 7, // lossy ulaw
kTypeAU2 = 8, // new ulaw with zero mapping
kTypeAU3 = 9, // lossless alaw
kTypeALaw = 10, // lossy alaw
kTypeWAV = 11, // WAV
kTypeAIFF = 12, // AIFF
kTypeEOF = 13,
kTypeGenericULaw = 128,
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kTypeGenericALaw = 129
};
enum kShortenCommands {
kCmdDiff0 = 0,
kCmdDiff1 = 1,
kCmdDiff2 = 2,
kCmdDiff3 = 3,
kCmdQuit = 4,
kCmdBlockSize = 5,
kCmdBitShift = 6,
kCmdQLPC = 7,
kCmdZero = 8,
kCmdVerbatim = 9
};
#ifndef M_LN2
#define M_LN2 0.69314718055994530942
#endif
// ---------------------------------------------------------------------------
class ShortenGolombReader {
public:
ShortenGolombReader(Common::ReadStream *stream, int version);
~ShortenGolombReader() {}
uint32 getUint32(uint32 numBits); // UINT_GET
int32 getURice(uint32 numBits); // uvar_get
int32 getSRice(uint32 numBits); // var_get
private:
int _version;
uint32 _nbitget;
uint32 _buf;
uint32 _masktab[MASKTABSIZE];
Common::ReadStream *_stream;
};
ShortenGolombReader::ShortenGolombReader(Common::ReadStream *stream, int version) {
_stream = stream;
_version = version;
uint32 val = 0;
_masktab[0] = 0;
_nbitget = 0;
_buf = 0;
for (int i = 1; i < MASKTABSIZE; i++) {
val <<= 1;
val |= 1;
_masktab[i] = val;
}
}
int32 ShortenGolombReader::getURice(uint32 numBits) {
int32 result = 0;
if (!_nbitget) {
_buf = _stream->readUint32BE();
_nbitget = 32;
}
for (result = 0; !(_buf & (1L << --_nbitget)); result++) {
if (!_nbitget) {
_buf = _stream->readUint32BE();
_nbitget = 32;
}
}
while (numBits != 0) {
if (_nbitget >= numBits) {
result = (result << numBits) | ((_buf >> (_nbitget - numBits)) & _masktab[numBits]);
_nbitget -= numBits;
numBits = 0;
} else {
result = (result << _nbitget) | (_buf & _masktab[_nbitget]);
_buf = _stream->readUint32BE();
numBits -= _nbitget;
_nbitget = 32;
}
}
return result;
}
int32 ShortenGolombReader::getSRice(uint32 numBits) {
uint32 uvar = (uint32) getURice(numBits + 1);
return (uvar & 1) ? (int32) ~(uvar >> 1) : (int32) (uvar >> 1);
}
uint32 ShortenGolombReader::getUint32(uint32 numBits) {
return (_version == 0) ? (uint32)getURice(numBits) : (uint32)getURice(getURice(2));
}
// ---------------------------------------------------------------------------
byte *loadShortenFromStream(Common::ReadStream &stream, int &size, int &rate, byte &flags) {
int32 *buffer[2], *offset[2]; // up to 2 channels
byte *unpackedBuffer = 0;
byte *pBuf = unpackedBuffer;
int prevSize = 0;
int32 *lpc = 0;
ShortenGolombReader *gReader;
uint32 i, j, version, mean, type, channels, blockSize;
uint32 maxLPC = 0, lpcqOffset = 0;
int32 bitShift = 0, wrap = 0;
flags = 0;
size = 0;
// Read header
byte magic[4];
stream.read(magic, 4);
if (memcmp(magic, "ajkg", 4) != 0) {
warning("loadShortenFromStream: No 'ajkg' header");
return NULL;
}
version = stream.readByte();
if (version > MAX_SUPPORTED_VERSION) {
warning("loadShortenFromStream: Can't decode version %d, maximum supported version is %d", version, MAX_SUPPORTED_VERSION);
return NULL;
}
mean = (version < 2) ? 0 : 4;
gReader = new ShortenGolombReader(&stream, version);
// Get file type
type = gReader->getUint32(4);
switch (type) {
case kTypeS8:
break;
case kTypeU8:
flags |= Audio::FLAG_UNSIGNED;
break;
case kTypeS16LH:
flags |= Audio::FLAG_LITTLE_ENDIAN;
case kTypeS16HL:
flags |= Audio::FLAG_16BITS;
break;
case kTypeU16LH:
flags |= Audio::FLAG_LITTLE_ENDIAN;
case kTypeU16HL:
flags |= Audio::FLAG_16BITS;
flags |= Audio::FLAG_UNSIGNED;
break;
case kTypeWAV:
// TODO: Perhaps implement this if we find WAV Shorten encoded files
warning("loadShortenFromStream: Type WAV is not supported");
delete gReader;
return NULL;
case kTypeAIFF:
// TODO: Perhaps implement this if we find AIFF Shorten encoded files
warning("loadShortenFromStream: Type AIFF is not supported");
delete gReader;
return NULL;
case kTypeAU1:
case kTypeAU2:
case kTypeAU3:
case kTypeULaw:
case kTypeALaw:
case kTypeEOF:
case kTypeGenericULaw:
case kTypeGenericALaw:
default:
warning("loadShortenFromStream: Type %d is not supported", type);
delete gReader;
return NULL;
}
// Get channels
channels = gReader->getUint32(0);
if (channels != 1 && channels != 2) {
warning("loadShortenFromStream: Only 1 or 2 channels are supported, stream contains %d channels", channels);
delete gReader;
return NULL;
}
// Get block size
if (version > 0) {
blockSize = gReader->getUint32((int) (log((double) DEFAULT_BLOCK_SIZE) / M_LN2));
maxLPC = gReader->getUint32(2);
mean = gReader->getUint32(0);
uint32 skipBytes = gReader->getUint32(1);
if (skipBytes > 0) {
prevSize = size;
size += skipBytes;
unpackedBuffer = (byte *) realloc(unpackedBuffer, size);
pBuf = unpackedBuffer + prevSize;
for (i = 0; i < skipBytes; i++) {
*pBuf++ = gReader->getUint32(7) & 0xFF;
}
}
} else {
blockSize = DEFAULT_BLOCK_SIZE;
}
wrap = MAX<uint32>(3, maxLPC);
// Initialize buffers
for (i = 0; i < channels; i++) {
buffer[i] = (int32 *)malloc((blockSize + wrap) * 4);
offset[i] = (int32 *)malloc((MAX<uint32>(1, mean)) * 4);
memset(buffer[i], 0, (blockSize + wrap) * 4);
memset(offset[i], 0, (MAX<uint32>(1, mean)) * 4);
}
if (maxLPC > 0)
lpc = (int32 *) malloc(maxLPC * 4);
if (version > 1)
lpcqOffset = 1 << 5;
// Init offset
int32 offsetMean = 0;
uint32 blocks = MAX<int>(1, mean);
if (type == kTypeU8)
offsetMean = 0x80;
else if (type == kTypeU16HL || type == kTypeU16LH)
offsetMean = 0x8000;
for (uint32 channel = 0; channel < channels; channel++)
for (uint32 block = 0; block < blocks; block++)
offset[channel][block] = offsetMean;
uint32 curChannel = 0, cmd = 0;
// Parse Shorten commands
while (true) {
cmd = gReader->getURice(2);
if (cmd == kCmdQuit)
break;
switch (cmd) {
case kCmdZero:
case kCmdDiff0:
case kCmdDiff1:
case kCmdDiff2:
case kCmdDiff3:
case kCmdQLPC:
{
int32 channelOffset = 0, energy = 0;
uint32 lpcNum = 0;
if (cmd != kCmdZero) {
energy = gReader->getURice(3);
// hack for version 0
if (version == 0)
energy--;
}
// Find mean offset (code duplicated below)
if (mean == 0) {
channelOffset = offset[curChannel][0];
} else {
int32 sum = (version < 2) ? 0 : mean / 2;
for (i = 0; i < mean; i++)
sum += offset[curChannel][i];
channelOffset = sum / mean;
if (version >= 2 && bitShift > 0)
channelOffset = (channelOffset >> (bitShift - 1)) >> 1;
}
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// FIXME: The original code in this bit tries to modify memory outside of the array (negative indices)
// in cases kCmdDiff1, kCmdDiff2 and kCmdDiff3
// I've removed those invalid writes, since they happen all the time (even when curChannel is 0)
switch (cmd) {
case kCmdZero:
for (i = 0; i < blockSize; i++)
buffer[curChannel][i] = 0;
break;
case kCmdDiff0:
for (i = 0; i < blockSize; i++)
buffer[curChannel][i] = gReader->getSRice(energy) + channelOffset;
break;
case kCmdDiff1:
gReader->getSRice(energy); // i = 0 (to fix invalid table/memory access)
for (i = 1; i < blockSize; i++)
buffer[curChannel][i] = gReader->getSRice(energy) + buffer[curChannel][i - 1];
break;
case kCmdDiff2:
gReader->getSRice(energy); // i = 0 (to fix invalid table/memory access)
gReader->getSRice(energy); // i = 1 (to fix invalid table/memory access)
for (i = 2; i < blockSize; i++)
buffer[curChannel][i] = gReader->getSRice(energy) + 2 * buffer[curChannel][i - 1] - buffer[curChannel][i - 2];
break;
case kCmdDiff3:
gReader->getSRice(energy); // i = 0 (to fix invalid table/memory access)
gReader->getSRice(energy); // i = 1 (to fix invalid table/memory access)
gReader->getSRice(energy); // i = 2 (to fix invalid table/memory access)
for (i = 3; i < blockSize; i++)
buffer[curChannel][i] = gReader->getSRice(energy) + 3 * (buffer[curChannel][i - 1] - buffer[curChannel][i - 2]) + buffer[curChannel][i - 3];
break;
case kCmdQLPC:
lpcNum = gReader->getURice(2);
// Safeguard: if maxLPC < lpcNum, realloc the lpc buffer
if (maxLPC < lpcNum) {
warning("Safeguard: maxLPC < lpcNum (should never happen)");
maxLPC = lpcNum;
int32 *tmp = (int32 *) realloc(lpc, maxLPC * 4);
if ((tmp != NULL) || (maxLPC == 0)) {
lpc = tmp;
} else {
error("loadShortenFromStream(): Error while reallocating memory");
}
}
for (i = 0; i < lpcNum; i++)
lpc[i] = gReader->getSRice(5);
for (i = 0; i < lpcNum; i++)
buffer[curChannel][i - lpcNum] -= channelOffset;
for (i = 0; i < blockSize; i++) {
int32 sum = lpcqOffset;
for (j = 0; j < lpcNum; j++) {
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// FIXME: The original code did an invalid memory access here
// (if i and j are 0, the array index requested is -1)
// I've removed those invalid writes, since they happen all the time (even when curChannel is 0)
if (i <= j) // ignore invalid table/memory access
continue;
sum += lpc[j] * buffer[curChannel][i - j - 1];
}
buffer[curChannel][i] = gReader->getSRice(energy) + (sum >> 5);
}
if (channelOffset > 0)
for (i = 0; i < blockSize; i++)
buffer[curChannel][i] += channelOffset;
break;
}
// Store mean value, if appropriate (duplicated code from above)
if (mean > 0) {
int32 sum = (version < 2) ? 0 : blockSize / 2;
for (i = 0; i < blockSize; i++)
sum += buffer[curChannel][i];
for (i = 1; i < mean; i++)
offset[curChannel][i - 1] = offset[curChannel][i];
offset[curChannel][mean - 1] = sum / blockSize;
if (version >= 2 && bitShift > 0)
offset[curChannel][mean - 1] = offset[curChannel][mean - 1] << bitShift;
}
// Do the wrap
// FIXME: removed for now, as this corrupts the heap, because it
// accesses negative array indices
//for (int32 k = -wrap; k < 0; k++)
// buffer[curChannel][k] = buffer[curChannel][k + blockSize];
// Fix bitshift
if (bitShift > 0) {
for (i = 0; i < blockSize; i++)
buffer[curChannel][i] <<= bitShift;
}
if (curChannel == channels - 1) {
int dataSize = (flags & Audio::FLAG_16BITS) ? 2 : 1;
int limit = (flags & Audio::FLAG_16BITS) ? 32767 : 127;
limit = (flags & Audio::FLAG_UNSIGNED) ? limit * 2 + 1 : limit;
prevSize = size;
size += (blockSize * dataSize);
byte *tmp = (byte *) realloc(unpackedBuffer, size);
if ((tmp != NULL) || (size == 0)) {
unpackedBuffer = tmp;
} else {
error("loadShortenFromStream(): Error while reallocating memory");
}
pBuf = unpackedBuffer + prevSize;
if (flags & Audio::FLAG_16BITS) {
for (i = 0; i < blockSize; i++) {
for (j = 0; j < channels; j++) {
int16 val = (int16)(MIN<int32>(buffer[j][i], limit) & 0xFFFF);
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// values are written in LE
*pBuf++ = (byte) (val & 0xFF);
*pBuf++ = (byte) ((val >> 8) & 0xFF);
}
}
} else {
for (i = 0; i < blockSize; i++)
for (j = 0; j < channels; j++)
*pBuf++ = (byte)(MIN<int32>(buffer[j][i], limit) & 0xFF);
}
}
curChannel = (curChannel + 1) % channels;
}
break;
case kCmdBlockSize:
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blockSize = gReader->getUint32((uint32)log((double) blockSize / M_LN2));
break;
case kCmdBitShift:
bitShift = gReader->getURice(2);
break;
case kCmdVerbatim:
{
uint32 vLen = (uint32)gReader->getURice(5);
prevSize = size;
size += vLen;
byte *tmp = (byte *) realloc(unpackedBuffer, size);
if ((tmp != NULL) || (size == 0)) {
unpackedBuffer = tmp;
} else {
error("loadShortenFromStream(): Error while reallocating memory");
}
pBuf = unpackedBuffer + prevSize;
while (vLen--) {
*pBuf++ = (byte)(gReader->getURice(8) & 0xFF);
}
}
break;
default:
warning("loadShortenFromStream: Unknown command: %d", cmd);
// Cleanup
for (i = 0; i < channels; i++) {
free(buffer[i]);
free(offset[i]);
}
if (maxLPC > 0)
free(lpc);
if (size > 0)
free(unpackedBuffer);
delete gReader;
return NULL;
break;
}
}
// Rate is always 44100Hz
rate = 44100;
// Cleanup
for (i = 0; i < channels; i++) {
free(buffer[i]);
free(offset[i]);
}
if (maxLPC > 0)
free(lpc);
if (size > 0)
free(unpackedBuffer);
delete gReader;
return unpackedBuffer;
}
Audio::AudioStream *makeShortenStream(Common::SeekableReadStream &stream) {
int size, rate;
byte *data, flags;
data = loadShortenFromStream(stream, size, rate, flags);
if (!data)
return 0;
// Since we allocated our own buffer for the data, we must specify DisposeAfterUse::YES.
return Audio::makeRawStream(data, size, rate, flags);
}
} // End of namespace Audio
#endif // defined(SOUND_SHORTEN_H)