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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 "scumm/cdda.h"
#include "common/stream.h"
#include "audio/audiostream.h"
namespace Scumm {
#pragma mark -
#pragma mark --- CDDA stream ---
#pragma mark -
#define START_OF_CDDA_DATA 800
#define BLOCK_SIZE 1177
class CDDAStream : public Audio::SeekableAudioStream {
private:
Common::SeekableReadStream *_stream;
DisposeAfterUse::Flag _disposeAfterUse;
byte _shiftLeft;
byte _shiftRight;
uint32 _pos;
Audio::Timestamp _length;
public:
CDDAStream(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse);
virtual ~CDDAStream();
int readBuffer(int16 *buffer, const int numSamples);
bool isStereo() const { return true; }
int getRate() const { return 44100; }
bool endOfData() const { return _stream->eos(); }
bool seek(const Audio::Timestamp &where);
Audio::Timestamp getLength() const { return _length; }
};
CDDAStream::CDDAStream(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse) :
_stream(stream), _disposeAfterUse(disposeAfterUse), _pos(START_OF_CDDA_DATA) {
_stream->seek(START_OF_CDDA_DATA, SEEK_SET);
// The total size of CDDA.SOU is 289,808,802 bytes or (289808802 - 800) / 1177 = 246226 blocks
// We also deduct the shift values to return the correct length
uint32 blocks = (_stream->size() - START_OF_CDDA_DATA) / BLOCK_SIZE;
_length = Audio::Timestamp(0, (_stream->size() - START_OF_CDDA_DATA - blocks) / (isStereo() ? 2 : 1), getRate());
}
CDDAStream::~CDDAStream() {
if (_disposeAfterUse == DisposeAfterUse::YES)
delete _stream;
}
bool CDDAStream::seek(const Audio::Timestamp &where) {
const uint32 seekSample = convertTimeToStreamPos(where, getRate(), isStereo()).totalNumberOfFrames();
uint32 blocks = seekSample / 1176;
// Before seeking, read the shift values from the beginning of that block
_stream->seek(START_OF_CDDA_DATA + blocks * BLOCK_SIZE, SEEK_SET);
byte shiftVal = _stream->readByte();
_shiftLeft = shiftVal >> 4;
_shiftRight = shiftVal & 0x0F;
_pos = START_OF_CDDA_DATA + blocks + seekSample;
return _stream->seek(_pos, SEEK_SET);
}
int CDDAStream::readBuffer(int16 *buffer, const int numSamples) {
int samples;
for (samples = 0 ; samples < numSamples && !_stream->eos() ; ) {
if (!((_pos - START_OF_CDDA_DATA) % BLOCK_SIZE)) {
byte shiftVal = _stream->readByte();
_shiftLeft = shiftVal >> 4;
_shiftRight = shiftVal & 0x0F;
_pos++;
}
buffer[samples++] = _stream->readSByte() << _shiftLeft;
buffer[samples++] = _stream->readSByte() << _shiftRight;
_pos += 2;
}
return samples;
}
#pragma mark -
#pragma mark --- CDDA factory functions ---
#pragma mark -
Audio::SeekableAudioStream *makeCDDAStream(
Common::SeekableReadStream *stream,
DisposeAfterUse::Flag disposeAfterUse) {
Audio::SeekableAudioStream *s = new CDDAStream(stream, disposeAfterUse);
if (s && s->endOfData()) {
delete s;
return 0;
} else {
return s;
}
return 0;
}
} // End of namespace Scumm
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