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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.
*
* $URL$
* $Id$
*
*/
/*
* The code in this file is based on information found at
* http://www.borg.com/~jglatt/tech/aiff.htm
*
* We currently only implement uncompressed AIFF. If we ever need AIFF-C, SoX
* (http://sox.sourceforge.net) may be a good place to start from.
*/
#include "common/endian.h"
#include "common/util.h"
#include "common/stream.h"
#include "sound/aiff.h"
#include "sound/audiostream.h"
#include "sound/mixer.h"
namespace Audio {
uint32 readExtended(Common::SeekableReadStream &stream) {
// The sample rate is stored as an "80 bit IEEE Standard 754 floating
// point number (Standard Apple Numeric Environment [SANE] data type
// Extended).
byte buf[10];
uint32 mantissa;
uint32 last = 0;
byte exp;
stream.read(buf, 10);
mantissa = READ_BE_UINT32(buf + 2);
exp = 30 - buf[1];
while (exp--) {
last = mantissa;
mantissa >>= 1;
}
if (last & 0x00000001)
mantissa++;
return mantissa;
}
bool loadAIFFFromStream(Common::SeekableReadStream &stream, int &size, int &rate, byte &flags) {
byte buf[4];
stream.read(buf, 4);
if (memcmp(buf, "FORM", 4) != 0) {
warning("loadAIFFFromStream: No 'FORM' header");
return false;
}
stream.readUint32BE();
// This could be AIFC, but we don't handle that case.
stream.read(buf, 4);
if (memcmp(buf, "AIFF", 4) != 0) {
warning("loadAIFFFromStream: No 'AIFF' header");
return false;
}
// From here on, we only care about the COMM and SSND chunks, which are
// the only required chunks.
bool foundCOMM = false;
bool foundSSND = false;
uint16 numChannels = 0, bitsPerSample = 0;
uint32 numSampleFrames = 0, offset = 0, blockSize = 0, soundOffset = 0;
while ((!foundCOMM || !foundSSND) && !stream.ioFailed()) {
uint32 length, pos;
stream.read(buf, 4);
length = stream.readUint32BE();
pos = stream.pos();
if (memcmp(buf, "COMM", 4) == 0) {
foundCOMM = true;
numChannels = stream.readUint16BE();
numSampleFrames = stream.readUint32BE();
bitsPerSample = stream.readUint16BE();
rate = readExtended(stream);
size = numSampleFrames * numChannels * (bitsPerSample / 8);
} else if (memcmp(buf, "SSND", 4) == 0) {
foundSSND = true;
offset = stream.readUint32BE();
blockSize = stream.readUint32BE();
soundOffset = stream.pos();
}
stream.seek(pos + length);
}
if (!foundCOMM) {
warning("loadAIFFFromStream: Cound not find 'COMM' chunk");
return false;
}
if (!foundSSND) {
warning("loadAIFFFromStream: Cound not find 'SSND' chunk");
return false;
}
// We only implement a subset of the AIFF standard.
if (numChannels < 1 || numChannels > 2) {
warning("loadAIFFFromStream: Only 1 or 2 channels are supported, not %d", numChannels);
return false;
}
if (bitsPerSample != 8 && bitsPerSample != 16) {
warning("loadAIFFFromStream: Only 8 or 16 bits per sample are supported, not %d", bitsPerSample);
return false;
}
if (offset != 0 || blockSize != 0) {
warning("loadAIFFFromStream: Block-aligned data is not supported");
return false;
}
// Samples are always signed, and big endian.
flags = 0;
if (bitsPerSample == 16)
flags |= Audio::Mixer::FLAG_16BITS;
if (numChannels == 2)
flags |= Audio::Mixer::FLAG_STEREO;
stream.seek(soundOffset);
// Stream now points at the sample data
return true;
}
AudioStream *makeAIFFStream(Common::SeekableReadStream &stream) {
int size, rate;
byte *data, flags;
if (!loadAIFFFromStream(stream, size, rate, flags))
return 0;
data = (byte *)malloc(size);
assert(data);
stream.read(data, size);
// Since we allocated our own buffer for the data, we must set the autofree flag.
flags |= Audio::Mixer::FLAG_AUTOFREE;
return makeLinearInputStream(data, size, rate, flags, 0, 0);
}
} // End of namespace Audio
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