aboutsummaryrefslogtreecommitdiff
path: root/sound/audiostream.cpp
blob: 748e480c613b1c5ed40dffc06c3b1d7c0ae5438d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
/* 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.
 *
 * $URL$
 * $Id$
 *
 */

#include "common/debug.h"
#include "common/endian.h"
#include "common/file.h"
#include "common/list.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"


// This used to be an inline template function, but
// buggy template function handling in MSVC6 forced
// us to go with the macro approach. So far this is
// the only template function that MSVC6 seemed to
// compile incorrectly. Knock on wood.
#define READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, ptr, isLE) \
	((is16Bit ? (isLE ? READ_LE_UINT16(ptr) : READ_BE_UINT16(ptr)) : (*ptr << 8)) ^ (isUnsigned ? 0x8000 : 0))


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).
	 */
	SeekableAudioStream *(*openStreamFile)(Common::SeekableReadStream *stream, bool disposeAfterUse);
};

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
};

SeekableAudioStream *SeekableAudioStream::openStreamFile(const Common::String &basename) {
	SeekableAudioStream *stream = NULL;
	Common::File *fileHandle = new Common::File();

	for (int i = 0; i < ARRAYSIZE(STREAM_FILEFORMATS)-1 && stream == NULL; ++i) {
		Common::String filename = basename + STREAM_FILEFORMATS[i].fileExtension;
		fileHandle->open(filename);
		if (fileHandle->isOpen()) {
			// Create the stream object
			stream = STREAM_FILEFORMATS[i].openStreamFile(fileHandle, true);
			fileHandle = 0;
			break;
		}
	}

	delete fileHandle;

	if (stream == NULL) {
		debug(1, "AudioStream: Could not open compressed AudioFile %s", basename.c_str());
	}

	return stream;
}

#pragma mark -
#pragma mark --- LinearMemoryStream ---
#pragma mark -

inline int32 calculatePlayTime(int rate, int samples) {
	int32 seconds = samples / rate;
	int32 milliseconds = (1000 * (samples % rate)) / rate;
	return seconds * 1000 + milliseconds;
}

uint32 calculateSampleOffset(const Timestamp &where, int rate) {
	const Timestamp whereRate = where.convertToFramerate(rate);
	return whereRate.secs() * rate + whereRate.numberOfFrames();
}

/**
 * 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 efficient as possible (without
 * resorting to assembly, that is). To this end, it is written as a template
 * class. This way the compiler can create optimized code for each special
 * case. 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 SeekableAudioStream {
protected:
	const byte *_ptr;
	const byte *_end;
	const byte *_loopPtr;
	const byte *_loopEnd;
	const int _rate;
	const byte *_origPtr;
	const int32 _playtime;

	uint _numLoops;			///< Number of loops to play
	uint _numPlayedLoops;	///< Number of loops which have been played

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), _playtime(calculatePlayTime(rate, len / (is16Bit ? 2 : 1) / (stereo ? 2 : 1))) {

		if (loopLen) {
			_numLoops = 0;
			_loopPtr = _ptr + loopOffset;
			_loopEnd = _loopPtr + loopLen;
		} else {
			_numLoops = 1;
		}
		_numPlayedLoops = 0;

		_origPtr = autoFreeMemory ? ptr : 0;
	}
	virtual ~LinearMemoryStream() {
		free(const_cast<byte *>(_origPtr));
	}
	int readBuffer(int16 *buffer, const int numSamples);

	bool isStereo() const			{ return stereo; }
	bool endOfData() const			{ return _ptr >= _end; }

	int getRate() const				{ return _rate; }
	bool seek(const Timestamp &where);
	// TODO: We can definitly increase the precision here, since we know the exact sample count
	Timestamp getLength() const { return Timestamp(_playtime, getRate()); }

	void setNumLoops(uint numLoops) {
		_numLoops = numLoops;
		_numPlayedLoops = 0;

		if (numLoops == 1) {
			_loopPtr = 0;
			_loopEnd = 0;
		} else {
			_loopPtr = _ptr;
			_loopEnd = _end;
		}
	}

	uint getNumPlayedLoops() { return _numPlayedLoops; }
};

template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
int LinearMemoryStream<stereo, is16Bit, isUnsigned, isLE>::readBuffer(int16 *buffer, const int numSamples) {
	int samples = numSamples;
	while (samples > 0 && _ptr < _end) {
		int len = MIN(samples, (int)(_end - _ptr) / (is16Bit ? 2 : 1));
		samples -= len;
		do {
			*buffer++ = READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, _ptr, isLE);
			_ptr += (is16Bit ? 2 : 1);
		} while (--len);
		// Loop, if looping was specified
		// TODO: Handle non-infinite loops
		if (_loopPtr && _ptr >= _end) {
			_ptr = _loopPtr;
			_end = _loopEnd;

			_numPlayedLoops++;
		}
	}
	return numSamples-samples;
}

template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
bool LinearMemoryStream<stereo, is16Bit, isUnsigned, isLE>::seek(const Timestamp &where) {
	const uint8 *ptr = _origPtr + calculateSampleOffset(where, getRate()) * (is16Bit ? 2 : 1) * (stereo ? 2 : 1);
	if (ptr > _end) {
		_ptr = _end;
		return false;
	} else if (ptr == _end) {
		_ptr = _end;
		return true;
	} else {
		_ptr = ptr;
		return true;
	}
}

#pragma mark -
#pragma mark --- LinearDiskStream ---
#pragma mark -



/**
 *  LinearDiskStream.  This can stream linear (PCM) audio from disk.  The
 *  function takes an pointer to an array of LinearDiskStreamAudioBlock which defines the
 *  start position and length of each block of uncompressed audio in the stream.
 */
template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
class LinearDiskStream : public SeekableAudioStream {

// Allow backends to override buffer size
#ifdef CUSTOM_AUDIO_BUFFER_SIZE
	static const int32 BUFFER_SIZE = CUSTOM_AUDIO_BUFFER_SIZE;
#else
	static const int32 BUFFER_SIZE = 16384;
#endif

	void setNumLoops(uint numLoops) {
		_numLoops = numLoops;
		_numPlayedLoops = 0;
	}
	uint getNumPlayedLoops() { return _numPlayedLoops; }

protected:
	byte* _buffer;			///< Streaming buffer
	const byte *_ptr;		///< Pointer to current position in stream buffer
	const int _rate;		///< Sample rate of stream

	int32 _playtime;		///< Calculated total play time
	Common::SeekableReadStream *_stream;	///< Stream to read data from
	int32 _filePos;			///< Current position in stream
	int32 _diskLeft;		///< Samples left in stream in current block not yet read to buffer
	int32 _bufferLeft;		///< Samples left in buffer in current block
	bool _disposeAfterUse;		///< If true, delete stream object when LinearDiskStream is destructed

	LinearDiskStreamAudioBlock *_audioBlock;	///< Audio block list
	int _audioBlockCount;		///< Number of blocks in _audioBlock
	int _currentBlock;		///< Current audio block number

	int _beginLoop;			///< Loop start parameter
	int _endLoop;			///< Loop end parameter, currently not implemented
	bool _loop;				///< Determines if the stream should be looped when it finishes
	uint _numLoops;			///< Number of loops to play
	uint _numPlayedLoops;	///< Number of loops which have been played

public:
	LinearDiskStream(int rate, uint beginLoop, uint endLoop, bool disposeStream, Common::SeekableReadStream *stream, LinearDiskStreamAudioBlock *block, uint numBlocks, bool loop)
		: _rate(rate), _stream(stream), _beginLoop(beginLoop), _endLoop(endLoop), _disposeAfterUse(disposeStream),
		  _audioBlockCount(numBlocks), _loop(loop), _numLoops(loop ? 0 : 1), _numPlayedLoops(0) {

		assert(numBlocks > 0);

		// Allocate streaming buffer
		if (is16Bit) {
			_buffer = (byte *)malloc(BUFFER_SIZE * sizeof(int16));
		} else {
			_buffer = (byte *)malloc(BUFFER_SIZE * sizeof(byte));
		}

		_ptr = _buffer;
		_bufferLeft = 0;

		// Copy audio block data to our buffer
		// TODO: Replace this with a Common::Array or Common::List to
		// make it a little friendlier.
		_audioBlock = new LinearDiskStreamAudioBlock[numBlocks];
		memcpy(_audioBlock, block, numBlocks * sizeof(LinearDiskStreamAudioBlock));

		// Set current buffer state, playing first block
		_currentBlock = 0;
		_filePos = _audioBlock[_currentBlock].pos;
		_diskLeft = _audioBlock[_currentBlock].len;

		// Add up length of all blocks in order to caluclate total play time
		int len = 0;
		for (int r = 0; r < _audioBlockCount; r++) {
			len += _audioBlock[r].len;
		}
		_playtime = calculatePlayTime(rate, len / (is16Bit ? 2 : 1) / (stereo ? 2 : 1));
	}


	virtual ~LinearDiskStream() {
		if (_disposeAfterUse) {
			delete _stream;
		}

		delete[] _audioBlock;
		free(_buffer);
	}
	int readBuffer(int16 *buffer, const int numSamples);

	bool isStereo() const			{ return stereo; }
	bool endOfData() const			{ return (_currentBlock == _audioBlockCount - 1) && (_diskLeft == 0) && (_bufferLeft == 0); }

	int getRate() const			{ return _rate; }
	// TODO: We can definitly increase the precision here, since we know the exact sample count
	Timestamp getLength() const { return Timestamp(_playtime, getRate()); }

	bool seek(const Timestamp &where);
};

template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
int LinearDiskStream<stereo, is16Bit, isUnsigned, isLE>::readBuffer(int16 *buffer, const int numSamples) {
	int oldPos = _stream->pos();
	bool restoreFilePosition = false;

	int samples = numSamples;

	while (samples > 0 && ((_diskLeft > 0 || _bufferLeft > 0) || (_currentBlock != _audioBlockCount - 1))  ) {
		// Output samples in the buffer to the output
		int len = MIN<int>(samples, _bufferLeft);
		samples -= len;
		_bufferLeft -= len;

		while (len > 0) {
			*buffer++ = READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, _ptr, isLE);
			_ptr += (is16Bit ? 2 : 1);
			len--;
		}

		// Have we now finished this block?  If so, read the next block
		if ((_bufferLeft == 0) && (_diskLeft == 0) && (_currentBlock != _audioBlockCount - 1)) {
			// Next block
			_currentBlock++;

			_filePos = _audioBlock[_currentBlock].pos;
			_diskLeft = _audioBlock[_currentBlock].len;
		}
			
		// Now read more data from disk if there is more to be read
		if ((_bufferLeft == 0) && (_diskLeft > 0)) {
			int32 readAmount = MIN(_diskLeft, BUFFER_SIZE);

			_stream->seek(_filePos, SEEK_SET);
			_stream->read(_buffer, readAmount * (is16Bit? 2: 1));

			// Amount of data in buffer is now the amount read in, and
			// the amount left to read on disk is decreased by the same amount
			_bufferLeft = readAmount;
			_diskLeft -= readAmount;
			_ptr = (byte *)_buffer;
			_filePos += readAmount * (is16Bit? 2: 1);

			// Set this flag now we've used the file, it restores it's
			// original position.
			restoreFilePosition = true;
		}

		// Looping
		if (_diskLeft == 0 && _loop) {
			// Reset the stream
			_currentBlock = 0;
			_filePos = _audioBlock[_currentBlock].pos + _beginLoop;
			_diskLeft = _audioBlock[_currentBlock].len;

			_numPlayedLoops++;
		}
	}

	// In case calling code relies on the position of this stream staying 
	// constant, I restore the location if I've changed it.  This is probably
	// not necessary.
	if (restoreFilePosition) {
		_stream->seek(oldPos, SEEK_SET);
	}

	return numSamples - samples;
}

template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
bool LinearDiskStream<stereo, is16Bit, isUnsigned, isLE>::seek(const Timestamp &where) {
	const uint32 seekSample = calculateSampleOffset(where, getRate()) * (stereo ? 2 : 1);
	uint32 curSample = 0;

	// Search for the disk block in which the specific sample is placed
	_currentBlock = 0;
	while (_currentBlock < _audioBlockCount) {
		uint32 nextBlockSample = curSample + _audioBlock[_currentBlock].len;

		if (nextBlockSample > seekSample)
			break;

		curSample = nextBlockSample;
		++_currentBlock;
	}

	_filePos = 0;
	_diskLeft = 0;
	_bufferLeft = 0;

	if (_currentBlock == _audioBlockCount) {
		return ((seekSample - curSample) == (uint32)_audioBlock[_currentBlock - 1].len);
	} else {
		const uint32 offset = seekSample - curSample;

		_filePos = _audioBlock[_currentBlock].pos + offset * (is16Bit? 2: 1);
		_diskLeft = _audioBlock[_currentBlock].len - offset;

		return true;
	}
}

#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)

SeekableAudioStream *makeLinearInputStream(const byte *ptr, uint32 len, int rate, byte flags, uint loopStart, uint loopEnd) {
	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;


	uint loopOffset = 0, loopLen = 0;
	if (flags & Audio::Mixer::FLAG_LOOP) {
		if (loopEnd == 0)
			loopEnd = len;
		assert(loopStart <= loopEnd);
		assert(loopEnd <= len);

		loopOffset = loopStart;
		loopLen = loopEnd - loopStart;
	}

	// Verify the buffer sizes are sane
	if (is16Bit && isStereo) {
		assert((len & 3) == 0 && (loopLen & 3) == 0);
	} else if (is16Bit || isStereo) {
		assert((len & 1) == 0 && (loopLen & 1) == 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);
		}
	}
}





#define MAKE_LINEAR_DISK(STEREO, UNSIGNED) \
		if (is16Bit) { \
			if (isLE) \
				return new LinearDiskStream<STEREO, true, UNSIGNED, true>(rate, loopStart, loopEnd, takeOwnership, stream, block, numBlocks, loop); \
			else  \
				return new LinearDiskStream<STEREO, true, UNSIGNED, false>(rate, loopStart, loopEnd, takeOwnership, stream, block, numBlocks, loop); \
		} else \
			return new LinearDiskStream<STEREO, false, UNSIGNED, false>(rate, loopStart, loopEnd, takeOwnership, stream, block, numBlocks, loop)


SeekableAudioStream *makeLinearDiskStream(Common::SeekableReadStream *stream, LinearDiskStreamAudioBlock *block, int numBlocks, int rate, byte flags, bool takeOwnership, uint loopStart, uint loopEnd) {
	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 loop       = (flags & Audio::Mixer::FLAG_LOOP) != 0;

	if (isStereo) {
		if (isUnsigned) {
			MAKE_LINEAR_DISK(true, true);
		} else {
			MAKE_LINEAR_DISK(true, false);
		}
	} else {
		if (isUnsigned) {
			MAKE_LINEAR_DISK(false, true);
		} else {
			MAKE_LINEAR_DISK(false, false);
		}
	}
}




#pragma mark -
#pragma mark --- Appendable audio stream ---
#pragma mark -

struct Buffer {
	byte *start;
	byte *end;
};

/**
 * Wrapped memory stream.
 */
class BaseAppendableMemoryStream : public AppendableAudioStream {
protected:

	// A mutex to avoid access problems (causing e.g. corruption of
	// the linked list) in thread aware environments.
	Common::Mutex _mutex;

	// List of all queued buffers
	Common::List<Buffer> _bufferQueue;

	// Position in the front buffer, if any
	bool _finalized;
	const int _rate;
	byte *_pos;

	inline bool eosIntern() const { return _bufferQueue.empty(); };
public:
	BaseAppendableMemoryStream(int rate);
	~BaseAppendableMemoryStream();

	bool endOfStream() const	{ return _finalized && eosIntern(); }
	bool endOfData() const		{ return eosIntern(); }

	int getRate() const			{ return _rate; }

	void finish()				{ _finalized = true; }

	void queueBuffer(byte *data, uint32 size);
};

/**
 * Wrapped memory stream.
 */
template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
class AppendableMemoryStream : public BaseAppendableMemoryStream {
public:
	AppendableMemoryStream(int rate) : BaseAppendableMemoryStream(rate) {}

	bool isStereo() const		{ return stereo; }

	int readBuffer(int16 *buffer, const int numSamples);
};

BaseAppendableMemoryStream::BaseAppendableMemoryStream(int rate)
 : _finalized(false), _rate(rate), _pos(0) {

}

BaseAppendableMemoryStream::~BaseAppendableMemoryStream() {
	// Clear the queue
	Common::List<Buffer>::iterator iter;
	for (iter = _bufferQueue.begin(); iter != _bufferQueue.end(); ++iter)
		delete[] iter->start;
}

template<bool stereo, bool is16Bit, bool isUnsigned, bool isLE>
int AppendableMemoryStream<stereo, is16Bit, isUnsigned, isLE>::readBuffer(int16 *buffer, const int numSamples) {
	Common::StackLock lock(_mutex);
	int samples = numSamples;
	while (samples > 0 && !eosIntern()) {
		Buffer buf = *_bufferQueue.begin();
		if (_pos == 0)
			_pos = buf.start;

		assert(buf.start <= _pos && _pos <= buf.end);
		const int samplesLeftInCurBuffer = buf.end - _pos;
		if (samplesLeftInCurBuffer == 0) {
			delete[] buf.start;
			_bufferQueue.erase(_bufferQueue.begin());
			_pos = 0;
			continue;
		}

		int len = MIN(samples, samplesLeftInCurBuffer / (is16Bit ? 2 : 1));
		samples -= len;
		do {
			*buffer++ = READ_ENDIAN_SAMPLE(is16Bit, isUnsigned, _pos, isLE);
			_pos += (is16Bit ? 2 : 1);
		} while (--len);
	}

	return numSamples - samples;
}

void BaseAppendableMemoryStream::queueBuffer(byte *data, uint32 size) {
	Common::StackLock lock(_mutex);

/*
	// Verify the buffer size is sane
	if (is16Bit && stereo) {
		assert((size & 3) == 0);
	} else if (is16Bit || stereo) {
		assert((size & 1) == 0);
	}
*/
	// Verify that the stream has not yet been finalized (by a call to finish())
	assert(!_finalized);

	// Queue the buffer
	Buffer buf = {data, data+size};
	_bufferQueue.push_back(buf);


#if 0
	// Output some stats
	uint totalSize = 0;
	Common::List<Buffer>::iterator iter;
	for (iter = _bufferQueue.begin(); iter != _bufferQueue.end(); ++iter)
		totalSize += iter->end - iter->start;
	printf("AppendableMemoryStream::queueBuffer: added a %d byte buf, a total of %d bytes are queued\n",
				size, totalSize);
#endif
}


#define MAKE_WRAPPED(STEREO, UNSIGNED) \
		if (is16Bit) { \
			if (isLE) \
				return new AppendableMemoryStream<STEREO, true, UNSIGNED, true>(rate); \
			else  \
				return new AppendableMemoryStream<STEREO, true, UNSIGNED, false>(rate); \
		} else \
			return new AppendableMemoryStream<STEREO, false, UNSIGNED, false>(rate)

AppendableAudioStream *makeAppendableAudioStream(int rate, byte _flags) {
	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;

	if (isStereo) {
		if (isUnsigned) {
			MAKE_WRAPPED(true, true);
		} else {
			MAKE_WRAPPED(true, false);
		}
	} else {
		if (isUnsigned) {
			MAKE_WRAPPED(false, true);
		} else {
			MAKE_WRAPPED(false, false);
		}
	}
}


} // End of namespace Audio