scummvm/audio/decoders/iff_sound.cpp
2011-05-12 01:16:22 +02:00

127 lines
3.2 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 "audio/decoders/iff_sound.h"
#include "audio/audiostream.h"
#include "audio/decoders/raw.h"
#include "common/iff_container.h"
#include "common/func.h"
namespace Audio {
struct Voice8Header {
uint32 oneShotHiSamples;
uint32 repeatHiSamples;
uint32 samplesPerHiCycle;
uint16 samplesPerSec;
byte octaves;
byte compression;
uint32 volume;
Voice8Header() {
memset(this, 0, sizeof(Voice8Header));
}
void load(Common::ReadStream &stream);
};
void Voice8Header::load(Common::ReadStream &stream) {
oneShotHiSamples = stream.readUint32BE();
repeatHiSamples = stream.readUint32BE();
samplesPerHiCycle = stream.readUint32BE();
samplesPerSec = stream.readUint16BE();
octaves = stream.readByte();
compression = stream.readByte();
volume = stream.readUint32BE();
}
struct A8SVXLoader {
Voice8Header _header;
int8 *_data;
uint32 _dataSize;
void load(Common::ReadStream &input) {
Common::IFFParser parser(&input);
Common::Functor1Mem< Common::IFFChunk&, bool, A8SVXLoader > c(this, &A8SVXLoader::callback);
parser.parse(c);
}
bool callback(Common::IFFChunk &chunk) {
switch (chunk._type) {
case ID_VHDR:
_header.load(*chunk._stream);
break;
case ID_BODY:
_dataSize = chunk._size;
_data = (int8*)malloc(_dataSize);
assert(_data);
loadData(chunk._stream);
return true;
}
return false;
}
void loadData(Common::ReadStream *stream) {
switch (_header.compression) {
case 0:
stream->read(_data, _dataSize);
break;
case 1:
// implement other formats here
error("compressed IFF audio is not supported");
break;
}
}
};
AudioStream *make8SVXStream(Common::ReadStream &input, bool loop) {
A8SVXLoader loader;
loader.load(input);
SeekableAudioStream *stream = Audio::makeRawStream((byte *)loader._data, loader._dataSize, loader._header.samplesPerSec, 0);
uint32 loopStart = 0, loopEnd = 0;
if (loop) {
// the standard way to loop 8SVX audio implies use of the oneShotHiSamples and
// repeatHiSamples fields
loopStart = 0;
loopEnd = loader._header.oneShotHiSamples + loader._header.repeatHiSamples;
if (loopStart != loopEnd) {
return new SubLoopingAudioStream(stream, 0,
Timestamp(0, loopStart, loader._header.samplesPerSec),
Timestamp(0, loopEnd, loader._header.samplesPerSec));
}
}
return stream;
}
}