mirror of
https://github.com/libretro/scummvm.git
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138 lines
3.3 KiB
C++
138 lines
3.3 KiB
C++
/* ScummVM - Graphic Adventure Engine
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*
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* ScummVM is the legal property of its developers, whose names
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* are too numerous to list here. Please refer to the COPYRIGHT
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* file distributed with this source distribution.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* $URL$
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* $Id$
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*
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*/
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#include "common/endian.h"
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#include "common/util.h"
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#include "made/sound.h"
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namespace Made {
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void decompressSound(byte *source, byte *dest, uint16 chunkSize, uint16 chunkCount) {
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int16 prevSample = 0, workSample = 0;
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byte soundBuffer[1025];
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byte deltaSoundBuffer[1024];
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int16 soundBuffer2[16];
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byte deltaType, type;
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uint16 workChunkSize, byteCount, bitCount;
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byte bitMask, bitShift;
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uint16 ofs = 0;
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uint16 i = 0, l = 0;
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byte val;
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const int modeValues[3][4] = {
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{ 2, 8, 0x01, 1},
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{ 4, 4, 0x03, 2},
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{16, 2, 0x0F, 4}
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};
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while (chunkCount--) {
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deltaType = (*source) >> 6;
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workChunkSize = chunkSize;
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if (deltaType == 1)
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workChunkSize /= 2;
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else if (deltaType == 2)
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workChunkSize /= 4;
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type = (*source++) & 0x0F;
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workSample = prevSample;
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switch (type) {
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case 0:
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memset(soundBuffer, 0x80, workChunkSize);
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workSample = 0;
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break;
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case 1:
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break;
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case 2:
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case 3:
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case 4:
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byteCount = modeValues[type - 2][0];
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bitCount = modeValues[type - 2][1];
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bitMask = modeValues[type - 2][2];
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bitShift = modeValues[type - 2][3];
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ofs = 0;
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for (i = 0; i < byteCount; i++)
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soundBuffer2[i] = (*source++) * 2 - 128;
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while (ofs < workChunkSize) {
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val = *source++;
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for (i = 0; i < bitCount; i++) {
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workSample = CLIP<int16>(workSample + soundBuffer2[val & bitMask], -127, 127);
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val >>= bitShift;
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soundBuffer[ofs++] = workSample + 128;
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}
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}
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break;
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case 5:
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for (i = 0; i < workChunkSize; i++)
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soundBuffer[i] = *source++;
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workSample = soundBuffer[workChunkSize - 1] - 128;
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break;
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default:
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return;
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}
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if (deltaType > 0) {
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if (deltaType == 1) {
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for (i = 0; i < chunkSize - 1; i += 2) {
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l = i / 2;
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deltaSoundBuffer[i] = soundBuffer[l];
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deltaSoundBuffer[i + 1] = (soundBuffer[l] + soundBuffer[l + 1]) / 2;
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}
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} else if (deltaType == 2) {
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for (i = 0; i < chunkSize - 1; i += 4) {
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l = i / 4;
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deltaSoundBuffer[i] = soundBuffer[l];
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deltaSoundBuffer[i + 2] = (soundBuffer[l] + soundBuffer[l + 1]) / 2;
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deltaSoundBuffer[i + 1] = (deltaSoundBuffer[i + 2] + soundBuffer[l]) / 2;
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deltaSoundBuffer[i + 3] = (deltaSoundBuffer[i + 2] + soundBuffer[l + 1]) / 2;
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}
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}
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for (i = 0; i < chunkSize; i++)
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soundBuffer[i] = deltaSoundBuffer[i];
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}
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prevSample = workSample;
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memcpy(dest, soundBuffer, chunkSize);
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dest += chunkSize;
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}
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}
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} // End of namespace Made
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