scummvm/sound/audiostream.cpp

92 lines
3.1 KiB
C++

/* ScummVM - Scumm Interpreter
* Copyright (C) 2001-2003 The ScummVM project
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*
*/
#include "audiostream.h"
#include "mixer.h"
template<int channels, int sampleSize>
class MemoryAudioInputStream : public AudioInputStream {
protected:
const byte *_ptr;
const byte *_end;
void advance() { _ptr += channels * sampleSize; }
public:
MemoryAudioInputStream(const byte *ptr, uint len) : _ptr(ptr), _end(ptr+len) { }
virtual int size() { return (_end - _ptr) / (channels * sampleSize); }
};
template<int channels>
class Input8bitSignedStream : public MemoryAudioInputStream<channels, 1> {
protected:
int16 readIntern() { int8 v = (int8)*_ptr; return v << 8; }
public:
Input8bitSignedStream(const byte *ptr, int len) : MemoryAudioInputStream<channels, 1>(ptr, len) { }
};
template<int channels>
class Input8bitUnsignedStream : public MemoryAudioInputStream<channels, 1> {
protected:
int16 readIntern() { int8 v = (int8)(*_ptr ^ 0x80); return v << 8; }
public:
Input8bitUnsignedStream(const byte *ptr, int len) : MemoryAudioInputStream<channels, 1>(ptr, len) { }
};
template<int channels>
class Input16bitSignedStream : public MemoryAudioInputStream<channels, 2> {
protected:
int16 readIntern() { return (int16)READ_BE_UINT16(_ptr); }
public:
Input16bitSignedStream(const byte *ptr, int len) : MemoryAudioInputStream<channels, 2>(ptr, len) { }
};
template<int channels>
class Input16bitUnsignedStream : public MemoryAudioInputStream<channels, 2> {
protected:
int16 readIntern() { return (int16)(READ_BE_UINT16(_ptr) ^ 0x8000); }
public:
Input16bitUnsignedStream(const byte *ptr, int len) : MemoryAudioInputStream<channels, 2>(ptr, len) { }
};
template<int channels>
static AudioInputStream *makeInputStream(const byte *ptr, uint32 len, bool isUnsigned, bool is16Bit) {
if (isUnsigned) {
if (is16Bit)
return new Input16bitUnsignedStream<channels>(ptr, len);
else
return new Input8bitUnsignedStream<channels>(ptr, len);
} else {
if (is16Bit)
return new Input16bitSignedStream<channels>(ptr, len);
else
return new Input8bitSignedStream<channels>(ptr, len);
}
}
AudioInputStream *makeInputStream(byte _flags, const byte *ptr, uint32 len) {
if (_flags & SoundMixer::FLAG_STEREO)
return makeInputStream<2>(ptr, len, _flags & SoundMixer::FLAG_UNSIGNED, _flags & SoundMixer::FLAG_16BITS);
else
return makeInputStream<1>(ptr, len, _flags & SoundMixer::FLAG_UNSIGNED, _flags & SoundMixer::FLAG_16BITS);
}