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/* ScummVM - Scumm Interpreter
* Copyright (C) 2005 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 "stdafx.h"
#include "common/util.h"
#include "common/stream.h"
#include "sound/audiostream.h"
#include "sound/mixer.h"
#include "sound/wave.h"
bool loadWAVFromStream(Common::SeekableReadStream &stream, int &size, int &rate, byte &flags) {
const uint32 initialPos = stream.pos();
byte buf[4+1];
buf[4] = 0;
stream.read(buf, 4);
if (memcmp(buf, "RIFF", 4) != 0) {
warning("getWavInfo: No 'RIFF' header");
return false;
}
uint32 wavLength = stream.readUint32LE();
stream.read(buf, 4);
if (memcmp(buf, "WAVE", 4) != 0) {
warning("getWavInfo: No 'WAVE' header");
return false;
}
stream.read(buf, 4);
if (memcmp(buf, "fmt ", 4) != 0) {
warning("getWavInfo: No 'fmt' header");
return false;
}
uint32 fmtLength = stream.readUint32LE();
if (fmtLength < 16) {
// A valid fmt chunk always contains at least 16 bytes
warning("getWavInfo: 'fmt' header is too short");
return false;
}
// Next comes the "type" field of the fmt header. Some typical
// values for it:
// 1 -> uncompressed PCM
// See <http://www.sonicspot.com/guide/wavefiles.html> for a more complete
// list of common WAVE compression formats...
uint16 type = stream.readUint16LE(); // == 1 for PCM data
uint16 numChannels = stream.readUint16LE(); // 1 for mono, 2 for stereo
uint32 samplesPerSec = stream.readUint32LE(); // in Hz
uint32 avgBytesPerSec = stream.readUint32LE(); // == SampleRate * NumChannels * BitsPerSample/8
uint16 blockAlign = stream.readUint16LE(); // == NumChannels * BitsPerSample/8
uint16 bitsPerSample = stream.readUint16LE(); // 8, 16 ...
// 8 bit data is unsigned, 16 bit data signed
#if 0
printf("WAVE information:\n");
printf(" total size: %d\n", wavLength);
printf(" fmt size: %d\n", fmtLength);
printf(" type: %d\n", type);
printf(" numChannels: %d\n", numChannels);
printf(" samplesPerSec: %d\n", samplesPerSec);
printf(" avgBytesPerSec: %d\n", avgBytesPerSec);
printf(" blockAlign: %d\n", blockAlign);
printf(" bitsPerSample: %d\n", bitsPerSample);
#endif
if (type != 1) {
warning("getWavInfo: only PCM data is supported (type %d)", type);
return false;
}
if (blockAlign != numChannels * bitsPerSample / 8) {
debug(0, "getWavInfo: blockAlign is invalid");
}
if (avgBytesPerSec != samplesPerSec * blockAlign) {
debug(0, "getWavInfo: avgBytesPerSec is invalid");
}
// Prepare the return values.
rate = samplesPerSec;
flags = 0;
if (bitsPerSample == 8) // 8 bit data is unsigned
flags |= SoundMixer::FLAG_UNSIGNED;
else if (bitsPerSample == 16) // 16 bit data is signed little endian
flags |= (SoundMixer::FLAG_16BITS | SoundMixer::FLAG_LITTLE_ENDIAN);
else {
warning("getWavInfo: unsupported bitsPerSample %d", bitsPerSample);
return false;
}
if (numChannels == 2)
flags |= SoundMixer::FLAG_STEREO;
else if (numChannels != 1) {
warning("getWavInfo: unsupported number of channels %d", numChannels);
return false;
}
// It's almost certainly a WAV file, but we still need to find its
// 'data' chunk.
// Skip over the rest of the fmt chunk.
int offset = fmtLength - 16;
do {
stream.seek(offset, SEEK_CUR);
if (stream.pos() >= initialPos + wavLength + 8) {
warning("getWavInfo: Can't find 'data' chunk");
return false;
}
stream.read(buf, 4);
offset = stream.readUint32LE();
#if 0
printf(" found a '%s' tag of size %d\n", buf, offset);
#endif
} while (memcmp(buf, "data", 4) != 0);
// Stream now points at 'offset' bytes of sample data...
size = offset;
return true;
}
AudioStream *makeWAVStream(Common::SeekableReadStream &stream) {
int size, rate;
byte flags;
if (!loadWAVFromStream(stream, size, rate, flags))
return 0;
byte *data = (byte *)malloc(size);
assert(data);
stream.read(data, size);
flags |= SoundMixer::FLAG_AUTOFREE;
return makeLinearInputStream(rate, flags, data, size, 0, 0);
}
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