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/* ScummVM - Scumm Interpreter
* Copyright (C) 2001-2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#include "common/stdafx.h"
#include "common/endian.h"
#include "common/file.h"
#include "common/util.h"
#include "sound/audiostream.h"
#include "sound/mixer.h"
#include "sound/mp3.h"
#include "sound/vorbis.h"
#include "sound/flac.h"
namespace Audio {
struct StreamFileFormat {
/** Decodername */
const char* decoderName;
const char* fileExtension;
/**
* Pointer to a function which tries to open a file of type StreamFormat.
* Return NULL in case of an error (invalid/nonexisting file).
*/
AudioStream* (*openStreamFile)(Common::File *file, uint32 size);
};
static const StreamFileFormat STREAM_FILEFORMATS[] = {
/* decoderName, fileExt, openStreamFuntion */
#ifdef USE_FLAC
{ "Flac", "flac", makeFlacStream },
{ "Flac", "fla", makeFlacStream },
#endif
#ifdef USE_VORBIS
{ "Ogg Vorbis", "ogg", makeVorbisStream },
#endif
#ifdef USE_MAD
{ "MPEG Layer 3", "mp3", makeMP3Stream },
#endif
{ NULL, NULL, NULL } // Terminator
};
AudioStream* AudioStream::openStreamFile(const char *filename)
{
char buffer[1024];
const uint len = strlen(filename);
assert(len+6 < sizeof(buffer)); // we need a bigger buffer if wrong
memcpy(buffer, filename, len);
buffer[len] = '.';
char *ext = &buffer[len+1];
AudioStream* stream = NULL;
Common::File *fileHandle = new Common::File();
for (int i = 0; i < ARRAYSIZE(STREAM_FILEFORMATS)-1 && stream == NULL; ++i) {
strcpy(ext, STREAM_FILEFORMATS[i].fileExtension);
fileHandle->open(buffer);
if (fileHandle->isOpen())
stream = STREAM_FILEFORMATS[i].openStreamFile(fileHandle, fileHandle->size());
}
// Do not reference the file anymore. If the stream didn't incRef the file,
// the object will be deleted (and the file be closed).
fileHandle->decRef();
if (stream == NULL) {
debug(1, "AudioStream: Could not open compressed AudioFile %s", filename);
}
return stream;
}
#pragma mark -
#pragma mark --- LinearMemoryStream ---
#pragma mark -
/**
* A simple raw audio stream, purely memory based. It operates on a single
* block of data, which is passed to it upon creation.
* Optionally supports looping the sound.
*
* Design note: This code tries to be as optimized as possible (without
* resorting to assembly, that is). To this end, it is written as a template
* class. This way the compiler can actually create optimized code for each
* special code. This results in a total of 12 versions of the code being
* generated.
*/
template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
class LinearMemoryStream : public AudioStream {
protected:
const byte *_ptr;
const byte *_end;
const byte *_loopPtr;
const byte *_loopEnd;
const int _rate;
const byte *_origPtr;
inline bool eosIntern() const { return _ptr >= _end; };
public:
LinearMemoryStream(int rate, const byte *ptr, uint len, uint loopOffset, uint loopLen, bool autoFreeMemory)
: _ptr(ptr), _end(ptr+len), _loopPtr(0), _loopEnd(0), _rate(rate) {
// Verify the buffer sizes are sane
if (is16Bit && stereo)
assert((len & 3) == 0 && (loopLen & 3) == 0);
else if (is16Bit || stereo)
assert((len & 1) == 0 && (loopLen & 1) == 0);
if (loopLen) {
_loopPtr = _ptr + loopOffset;
_loopEnd = _loopPtr + loopLen;
}
if (stereo) // Stereo requires even sized data
assert(len % 2 == 0);
_origPtr = autoFreeMemory ? ptr : 0;
}
~LinearMemoryStream() {
free(const_cast<byte *>(_origPtr));
}
int readBuffer(int16 *buffer, const int numSamples);
bool isStereo() const { return stereo; }
bool endOfData() const { return eosIntern(); }
int getRate() const { return _rate; }
};
template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
int LinearMemoryStream<stereo, is16Bit, isUnsigned, isLE>::readBuffer(int16 *buffer, const int numSamples) {
int samples = 0;
while (samples < numSamples && !eosIntern()) {
const int len = MIN(numSamples, samples + (int)(_end - _ptr) / (is16Bit ? 2 : 1));
while (samples < len) {
*buffer++ = READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, _ptr, isLE);
_ptr += (is16Bit ? 2 : 1);
samples++;
}
// Loop, if looping was specified
if (_loopPtr && eosIntern()) {
_ptr = _loopPtr;
_end = _loopEnd;
}
}
return samples;
}
#pragma mark -
#pragma mark --- Input stream factory ---
#pragma mark -
/* In the following, we use preprocessor / macro tricks to simplify the code
* which instantiates the input streams. We used to use template functions for
* this, but MSVC6 / EVC 3-4 (used for WinCE builds) are extremely buggy when it
* comes to this feature of C++... so as a compromise we use macros to cut down
* on the (source) code duplication a bit.
* So while normally macro tricks are said to make maintenance harder, in this
* particular case it should actually help it :-)
*/
#define MAKE_LINEAR(STEREO, UNSIGNED) \
if (is16Bit) { \
if (isLE) \
return new LinearMemoryStream<STEREO, true, UNSIGNED, true>(rate, ptr, len, loopOffset, loopLen, autoFree); \
else \
return new LinearMemoryStream<STEREO, true, UNSIGNED, false>(rate, ptr, len, loopOffset, loopLen, autoFree); \
} else \
return new LinearMemoryStream<STEREO, false, UNSIGNED, false>(rate, ptr, len, loopOffset, loopLen, autoFree)
AudioStream *makeLinearInputStream(int rate, byte flags, const byte *ptr, uint32 len, uint loopOffset, uint loopLen) {
const bool isStereo = (flags & Audio::Mixer::FLAG_STEREO) != 0;
const bool is16Bit = (flags & Audio::Mixer::FLAG_16BITS) != 0;
const bool isUnsigned = (flags & Audio::Mixer::FLAG_UNSIGNED) != 0;
const bool isLE = (flags & Audio::Mixer::FLAG_LITTLE_ENDIAN) != 0;
const bool autoFree = (flags & Audio::Mixer::FLAG_AUTOFREE) != 0;
if (isStereo) {
if (isUnsigned) {
MAKE_LINEAR(true, true);
} else {
MAKE_LINEAR(true, false);
}
} else {
if (isUnsigned) {
MAKE_LINEAR(false, true);
} else {
MAKE_LINEAR(false, false);
}
}
}
} // End of namespace Audio
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