scummvm/engines/bladerunner/aud_stream.cpp
2016-10-22 20:24:57 +02:00

117 lines
2.9 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.
*
*/
#include "bladerunner/aud_stream.h"
#include "bladerunner/audio_player.h"
#include "common/util.h"
namespace BladeRunner {
AudStream::AudStream(byte *data) : _cache(nullptr) {
init(data);
}
AudStream::AudStream(AudioCache *cache, int32 hash)
: _cache(cache), _hash(hash) {
_cache->incRef(_hash);
init(_cache->findByHash(_hash));
}
void AudStream::init(byte *data) {
_data = data;
_end = _data + READ_LE_UINT32(_data + 2) + 12;
assert(_end - _data >= 12);
_compressionType = *(_data + 11);
_deafBlockRemain = 0;
_p = _data + 12;
}
AudStream::~AudStream() {
if (_cache)
_cache->decRef(_hash);
}
int AudStream::readBuffer(int16 *buffer, const int numSamples) {
int samplesRead = 0;
if (_compressionType == 99) {
assert(numSamples % 2 == 0);
while (samplesRead < numSamples) {
if (_deafBlockRemain == 0) {
if (_end - _p == 0)
break;
assert(_end - _p >= 6);
uint16 blockSize = READ_LE_UINT16(_p);
uint16 blockOutSize = READ_LE_UINT16(_p + 2);
uint32 sig = READ_LE_UINT32(_p + 4);
_p += 8;
assert(sig == 0xdeaf);
assert(_end - _p >= blockSize);
// TODO: Previously we asserted that
// blockOutSize == 4 * blockSize, but
// occasionally, at the end of an AUD,
// we see blockOutSize == 4 * blockSize + 2
// Investigate how BLADE.EXE handles this.
assert(blockOutSize / 4 == blockSize);
_deafBlockRemain = blockSize;
}
assert(_end - _p >= _deafBlockRemain);
int bytesConsumed = MIN<int>(_deafBlockRemain, (numSamples - samplesRead) / 2);
_decoder.decode(_p, bytesConsumed, buffer + samplesRead);
_p += bytesConsumed;
_deafBlockRemain -= bytesConsumed;
samplesRead += 2 * bytesConsumed;
}
} else {
samplesRead = MIN(numSamples, (int)(_end - _p) / 2);
for (int i = 0; i < samplesRead; i++, _p += 2) {
buffer[i] = READ_LE_UINT16(_p);
}
}
return samplesRead;
}
bool AudStream::rewind() {
_p = _data + 12;
_decoder.setParameters(0, 0);
return true;
}
} // End of namespace BladeRunner