aboutsummaryrefslogtreecommitdiff
path: root/graphics/video/smk_decoder.cpp
blob: 8952f553b71acd3016a404a66da02bc532a6eddc (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
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
/* 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.
 *
 * $URL$
 * $Id$
 *
 */

// Based on http://wiki.multimedia.cx/index.php?title=Smacker
// and the FFmpeg Smacker decoder (libavcodec/smacker.c), revision 16143
// http://svn.ffmpeg.org/ffmpeg/trunk/libavcodec/smacker.c?revision=16143&view=markup

#include "graphics/video/smk_decoder.h"

#include "common/archive.h"
#include "common/endian.h"
#include "common/util.h"
#include "common/stream.h"
#include "common/system.h"

#include "sound/mixer.h"
#include "sound/audiostream.h"

namespace Graphics {

enum SmkBlockTypes {
	SMK_BLOCK_MONO = 0,
	SMK_BLOCK_FULL = 1,
	SMK_BLOCK_SKIP = 2,
	SMK_BLOCK_FILL = 3
};

/*
 * class BitStream
 * Little-endian bit stream provider.
 */

class BitStream {
public:
	BitStream(byte *buf, uint32 length)
		: _buf(buf), _end(buf+length), _bitCount(8) {
		_curByte = *_buf++;
	}

	bool getBit();
	byte getBits8();

	byte peek8() const;
	void skip(int n);

private:
	byte *_buf;
	byte *_end;
	byte _curByte;
	byte  _bitCount;
};

bool BitStream::getBit() {
	if (_bitCount == 0) {
		assert(_buf < _end);
		_curByte = *_buf++;
		_bitCount = 8;
	}

	bool v = _curByte & 1;

	_curByte >>= 1;
	--_bitCount;

	return v;
}

byte BitStream::getBits8() {
	assert(_buf < _end);

	byte v = (*_buf << _bitCount) | _curByte;
	_curByte = *_buf++ >> (8 - _bitCount);

	return v;
}

byte BitStream::peek8() const {
	if (_buf == _end)
		return _curByte;

	assert(_buf < _end);
	return (*_buf << _bitCount) | _curByte;
}

void BitStream::skip(int n) {
	assert(n <= 8);
	_curByte >>= n;

	if (_bitCount >= n) {
		_bitCount -= n;
	} else {
		assert(_buf < _end);
		_bitCount = _bitCount + 8 - n;
		_curByte = *_buf++ >> (8 - _bitCount);
	}
}

/*
 * class SmallHuffmanTree
 * A Huffman-tree to hold 8-bit values.
 */

class SmallHuffmanTree {
public:
	SmallHuffmanTree(BitStream &bs);

	uint16 getCode(BitStream &bs);
private:
	enum {
		SMK_NODE = 0x8000
	};

	uint16 decodeTree(uint32 prefix, int length);

	uint16 _treeSize;
	uint16 _tree[511];

	uint16 _prefixtree[256];
	byte _prefixlength[256];

	BitStream &_bs;
};

SmallHuffmanTree::SmallHuffmanTree(BitStream &bs)
	: _treeSize(0), _bs(bs) {
	uint32 bit = _bs.getBit();
	assert(bit);

	for (uint16 i = 0; i < 256; ++i)
		_prefixtree[i] = _prefixlength[i] = 0;

	decodeTree(0, 0);

	bit = _bs.getBit();
	assert(!bit);
}

uint16 SmallHuffmanTree::decodeTree(uint32 prefix, int length) {
	if (!_bs.getBit()) { // Leaf
		_tree[_treeSize] = _bs.getBits8();

		if (length <= 8) {
			for (int i = 0; i < 256; i += (1 << length)) {
				_prefixtree[prefix | i] = _treeSize;
				_prefixlength[prefix | i] = length;
			}
		}
		++_treeSize;

		return 1;
	}

	uint16 t = _treeSize++;

	if (length == 8) {
		_prefixtree[prefix] = t;
		_prefixlength[prefix] = 8;
	}

	uint16 r1 = decodeTree(prefix, length + 1);

	_tree[t] = (SMK_NODE | r1);

	uint16 r2 = decodeTree(prefix | (1 << length), length + 1);

	return r1+r2+1;
}

uint16 SmallHuffmanTree::getCode(BitStream &bs) {
	byte peek = bs.peek8();
	uint16 *p = &_tree[_prefixtree[peek]];
	bs.skip(_prefixlength[peek]);

	while (*p & SMK_NODE) {
		if (bs.getBit())
			p += *p & ~SMK_NODE;
		p++;
	}

	return *p;
}

/*
 * class BigHuffmanTree
 * A Huffman-tree to hold 16-bit values.
 */

class BigHuffmanTree {
public:
	BigHuffmanTree(BitStream &bs, int allocSize);
	~BigHuffmanTree();

	void reset();
	uint32 getCode(BitStream &bs);
private:
	enum {
		SMK_NODE = 0x80000000
	};

	uint32 decodeTree(uint32 prefix, int length);

	uint32  _treeSize;
	uint32 *_tree;
	uint32  _last[3];

	uint32 _prefixtree[256];
	byte _prefixlength[256];

	/* Used during construction */
	BitStream &_bs;
	uint32 _markers[3];
	SmallHuffmanTree *_loBytes;
	SmallHuffmanTree *_hiBytes;
};

BigHuffmanTree::BigHuffmanTree(BitStream &bs, int allocSize)
	: _bs(bs) {
	uint32 bit = _bs.getBit();
	if (!bit) {
		_tree = new uint32[1];
		_tree[0] = 0;
		_last[0] = _last[1] = _last[2] = 0;
		return;
	}

	for (uint32 i = 0; i < 256; ++i)
		_prefixtree[i] = _prefixlength[i] = 0;

	_loBytes = new SmallHuffmanTree(_bs);
	_hiBytes = new SmallHuffmanTree(_bs);

	_markers[0] = _bs.getBits8() | (_bs.getBits8() << 8);
	_markers[1] = _bs.getBits8() | (_bs.getBits8() << 8);
	_markers[2] = _bs.getBits8() | (_bs.getBits8() << 8);

	_last[0] = _last[1] = _last[2] = 0xffffffff;

	_treeSize = 0;
	_tree = new uint32[allocSize / 4];
	decodeTree(0, 0);
	bit = _bs.getBit();
	assert(!bit);

	for (uint32 i = 0; i < 3; ++i) {
		if (_last[i] == 0xffffffff) {
			_last[i] = _treeSize;
			_tree[_treeSize++] = 0;
		}
	}

	delete _loBytes;
	delete _hiBytes;
}

BigHuffmanTree::~BigHuffmanTree()
{
	delete[] _tree;
}

void BigHuffmanTree::reset() {
	_tree[_last[0]] = _tree[_last[1]] = _tree[_last[2]] = 0;
}

uint32 BigHuffmanTree::decodeTree(uint32 prefix, int length) {
	uint32 bit = _bs.getBit();

	if (!bit) { // Leaf
		uint32 lo = _loBytes->getCode(_bs);
		uint32 hi = _hiBytes->getCode(_bs);

		uint32 v = (hi << 8) | lo;

		_tree[_treeSize] = v;

		if (length <= 8) {
			for (int i = 0; i < 256; i += (1 << length)) {
				_prefixtree[prefix | i] = _treeSize;
				_prefixlength[prefix | i] = length;
			}
		}

		for (int i = 0; i < 3; ++i) {
			if (_markers[i] == v) {
				_last[i] = _treeSize;
				_tree[_treeSize] = 0;
			}
		}
		++_treeSize;

		return 1;
	}

	uint32 t = _treeSize++;

	if (length == 8) {
		_prefixtree[prefix] = t;
		_prefixlength[prefix] = 8;
	}

	uint32 r1 = decodeTree(prefix, length + 1);

	_tree[t] = SMK_NODE | r1;

	uint32 r2 = decodeTree(prefix | (1 << length), length + 1);
	return r1+r2+1;
}

uint32 BigHuffmanTree::getCode(BitStream &bs) {
	byte peek = bs.peek8();
	uint32 *p = &_tree[_prefixtree[peek]];
	bs.skip(_prefixlength[peek]);

	while (*p & SMK_NODE) {
		if (bs.getBit())
			p += (*p) & ~SMK_NODE;
		p++;
	}

	uint32 v = *p;
	if (v != _tree[_last[0]]) {
		_tree[_last[2]] = _tree[_last[1]];
		_tree[_last[1]] = _tree[_last[0]];
		_tree[_last[0]] = v;
	}

	return v;
}

SmackerDecoder::SmackerDecoder(Audio::Mixer *mixer, Audio::Mixer::SoundType soundType)
	: _audioStarted(false), _audioStream(0), _mixer(mixer), _soundType(soundType) {
}

SmackerDecoder::~SmackerDecoder() {
	closeFile();
}

int SmackerDecoder::getHeight() {
	if (!_fileStream)
		return 0;
	return (_header.flags ? 2 : 1) * _videoInfo.height;
}

int32 SmackerDecoder::getAudioLag() {
	if (!_fileStream)
		return 0;

	int32 frameDelay = getFrameDelay();
	int32 videoTime = _videoInfo.currentFrame * frameDelay;
	int32 audioTime;

	if (!_audioStream) {
		/* No audio.
		   Calculate the lag by how much time has gone by since the first frame
		   and how much time *should* have passed.
		*/

		audioTime = (g_system->getMillis() - _videoInfo.startTime) * 100;
	} else
		audioTime = (((int32) _mixer->getSoundElapsedTime(_audioHandle)) * 100);

	return videoTime - audioTime;
}

bool SmackerDecoder::loadFile(const char *fileName) {
	int32 frameRate;

	closeFile();

	_fileStream = SearchMan.createReadStreamForMember(fileName);
	if (!_fileStream)
		return false;

	// Seek to the first frame
	_videoInfo.currentFrame = 0;
	_header.signature = _fileStream->readUint32BE();

	// No BINK support available
	if (_header.signature == MKID_BE('BIKi')) {
		delete _fileStream;
		_fileStream = 0;
		return false;
	}

	assert(_header.signature == MKID_BE('SMK2') || _header.signature == MKID_BE('SMK4'));

	_videoInfo.width = _fileStream->readUint32LE();
	_videoInfo.height = _fileStream->readUint32LE();
	_videoInfo.frameCount = _fileStream->readUint32LE();
	frameRate = _fileStream->readSint32LE();

	if (frameRate > 0) {
		_videoInfo.frameRate = 1000 / frameRate;
		_videoInfo.frameDelay = frameRate * 100;
	} else if (frameRate < 0) {
		_videoInfo.frameRate = 100000 / (-frameRate);
		_videoInfo.frameDelay = -frameRate;
	} else {
		_videoInfo.frameRate = 10;
		_videoInfo.frameDelay = 10000;
	}

	// Flags are determined by which bit is set, which can be one of the following:
	// 0 - set to 1 if file contains a ring frame.
	// 1 - set to 1 if file is Y-interlaced
	// 2 - set to 1 if file is Y-doubled
	// If bits 1 or 2 are set, the frame should be scaled to twice its height
    // before it is displayed.
	_header.flags = _fileStream->readUint32LE();

	// TODO: should we do any extra processing for Smacker files with ring frames?

	// TODO: should we do any extra processing for Y-doubled videos? Are they the
	// same as Y-interlaced videos?

	uint32 i;
	for (i = 0; i < 7; ++i)
		_header.audioSize[i] = _fileStream->readUint32LE();

	_header.treesSize = _fileStream->readUint32LE();
	_header.mMapSize = _fileStream->readUint32LE();
	_header.mClrSize = _fileStream->readUint32LE();
	_header.fullSize = _fileStream->readUint32LE();
	_header.typeSize = _fileStream->readUint32LE();

	uint32 audioInfo;
	for (i = 0; i < 7; ++i) {
		// AudioRate - Frequency and format information for each sound track, up to 7 audio tracks.
		// The 32 constituent bits have the following meaning:
		// * bit 31 - data is compressed
		// * bit 30 - indicates that audio data is present for this track
		// * bit 29 - 1 = 16-bit audio; 0 = 8-bit audio
		// * bit 28 - 1 = stereo audio; 0 = mono audio
		// * bits 27-26 - if both set to zero - use v2 sound decompression
		// * bits 25-24 - unused
		// * bits 23-0 - audio sample rate
		audioInfo = _fileStream->readUint32LE();
		_header.audioInfo[i].isCompressed = audioInfo & 0x80000000;
		_header.audioInfo[i].hasAudio = audioInfo & 0x40000000;
		_header.audioInfo[i].is16Bits = audioInfo & 0x20000000;
		_header.audioInfo[i].isStereo = audioInfo & 0x10000000;
		_header.audioInfo[i].hasV2Compression = !(audioInfo & 0x8000000) &&
												!(audioInfo & 0x4000000);
		_header.audioInfo[i].sampleRate = audioInfo & 0xFFFFFF;

		if (_header.audioInfo[i].hasAudio && i == 0) {
			byte flags = 0;

			if (_header.audioInfo[i].is16Bits)
				flags = flags | Audio::Mixer::FLAG_16BITS;

			if (_header.audioInfo[i].isStereo)
				flags = flags | Audio::Mixer::FLAG_STEREO;

			_audioStream = Audio::makeAppendableAudioStream(_header.audioInfo[i].sampleRate, flags);
		}
	}

	_header.dummy = _fileStream->readUint32LE();

	_frameSizes = (uint32 *)malloc(_videoInfo.frameCount * sizeof(uint32));
	for (i = 0; i < _videoInfo.frameCount; ++i)
		_frameSizes[i] = _fileStream->readUint32LE();

	_frameTypes = (byte *)malloc(_videoInfo.frameCount);
	for (i = 0; i < _videoInfo.frameCount; ++i)
		_frameTypes[i] = _fileStream->readByte();

	byte *huffmanTrees = new byte[_header.treesSize];
	_fileStream->read(huffmanTrees, _header.treesSize);

	BitStream bs(huffmanTrees, _header.treesSize);

	_MMapTree = new BigHuffmanTree(bs, _header.mMapSize);
	_MClrTree = new BigHuffmanTree(bs, _header.mClrSize);
	_FullTree = new BigHuffmanTree(bs, _header.fullSize);
	_TypeTree = new BigHuffmanTree(bs, _header.typeSize);

	delete[] huffmanTrees;

	_videoFrameBuffer = (byte *)malloc(2 * _videoInfo.width * _videoInfo.height);
	memset(_videoFrameBuffer, 0, 2 * _videoInfo.width * _videoInfo.height);
	_palette = (byte *)malloc(3 * 256);
	memset(_palette, 0, 3 * 256);

	_videoInfo.firstframeOffset = _fileStream->pos();

	return true;
}

void SmackerDecoder::closeFile() {
	if (!_fileStream)
		return;

	if (_audioStarted && _audioStream) {
		_mixer->stopHandle(_audioHandle);
		_audioStream = 0;
		_audioStarted = false;
	}

	delete _fileStream;
	_fileStream = 0;

	delete _MMapTree;
	delete _MClrTree;
	delete _FullTree;
	delete _TypeTree;

	free(_frameSizes);
	free(_frameTypes);
	free(_videoFrameBuffer);
	free(_palette);
}

bool SmackerDecoder::decodeNextFrame() {
	uint i;
	uint32 chunkSize = 0;
	uint32 dataSizeUnpacked = 0;

	uint32 startPos = _fileStream->pos();

	if (_videoInfo.currentFrame == 0)
		_videoInfo.startTime = g_system->getMillis();

	// Check if we got a frame with palette data, and
	// call back the virtual setPalette function to set
	// the current palette
	if (_frameTypes[_videoInfo.currentFrame] & 1) {
		unpackPalette();
		setPalette(_palette);
	}

	// Load audio tracks
	for (i = 0; i < 7; ++i) {
		if (!(_frameTypes[_videoInfo.currentFrame] & (2 << i)))
			continue;

		chunkSize = _fileStream->readUint32LE();
		chunkSize -= 4;    // subtract the first 4 bytes (chunk size)

		if (_header.audioInfo[i].isCompressed) {
			dataSizeUnpacked = _fileStream->readUint32LE();
			chunkSize -= 4;    // subtract the next 4 bytes (unpacked data size)
		} else {
			dataSizeUnpacked = 0;
		}

		if (_header.audioInfo[i].hasAudio && chunkSize > 0 && i == 0) {
			// If it's track 0, play the audio data
			byte *soundBuffer = new byte[chunkSize];

			_fileStream->read(soundBuffer, chunkSize);

			if (_header.audioInfo[i].isCompressed) {
				// Compressed audio (Huffman DPCM encoded)
				queueCompressedBuffer(soundBuffer, chunkSize, dataSizeUnpacked, i);
				delete[] soundBuffer;
			} else {
				// Uncompressed audio (PCM)
				_audioStream->queueBuffer(soundBuffer, chunkSize);
				// The sound buffer will be deleted by AppendableAudioStream
			}

			if (!_audioStarted) {
				_mixer->playInputStream(_soundType, &_audioHandle, _audioStream, -1, 255);
				_audioStarted = true;
			}
		} else {
			// Ignore the rest of the audio tracks, if they exist
			// TODO: Are there any Smacker videos with more than one audio stream?
			// If yes, we should play the rest of the audio streams as well
			if (chunkSize > 0)
				_fileStream->skip(chunkSize);
		}
	}

	uint32 frameSize = _frameSizes[_videoInfo.currentFrame] & ~3;

	if (_fileStream->pos() - startPos > frameSize)
		exit(1);

	uint32 frameDataSize = frameSize - (_fileStream->pos() - startPos);

	_frameData = (byte *)malloc(frameDataSize);
	_fileStream->read(_frameData, frameDataSize);

	BitStream bs(_frameData, frameDataSize);

	_MMapTree->reset();
	_MClrTree->reset();
	_FullTree->reset();
	_TypeTree->reset();

	uint bw = _videoInfo.width / 4;
	uint bh = _videoInfo.height / 4;
	uint stride = _videoInfo.width;
	uint block = 0, blocks = bw*bh;

	uint doubleY = _header.flags ? 2 : 1;

	byte *out;
	uint type, run, j, mode;
	uint32 p1, p2, clr, map;
	byte hi, lo;

	while (block < blocks) {
		type = _TypeTree->getCode(bs);
		run = getBlockRun((type >> 2) & 0x3f);

		switch (type & 3) {
		case SMK_BLOCK_MONO:
			while (run-- && block < blocks) {
				clr = _MClrTree->getCode(bs);
				map = _MMapTree->getCode(bs);
				out = _videoFrameBuffer + (block / bw) * (stride * 4 * doubleY) + (block % bw) * 4;
				hi = clr >> 8;
				lo = clr & 0xff;
				for (i = 0; i < 4; i++) {
					for (j = 0; j < doubleY; j++) {
						out[0] = (map & 1) ? hi : lo;
						out[1] = (map & 2) ? hi : lo;
						out[2] = (map & 4) ? hi : lo;
						out[3] = (map & 8) ? hi : lo;
						out += stride;
					}
					map >>= 4;
				}
				++block;
			}
			break;
		case SMK_BLOCK_FULL:
			// Smacker v2 has one mode, Smacker v4 has three
			if (_header.signature == MKID_BE('SMK2')) {
				mode = 0;
			} else {
				// 00 - mode 0
				// 10 - mode 1
				// 01 - mode 2
				mode = 0;
				if (bs.getBit()) {
					mode = 1;
				} else if (bs.getBit()) {
					mode = 2;
				}
			}

			while (run-- && block < blocks) {
				out = _videoFrameBuffer + (block / bw) * (stride * 4 * doubleY) + (block % bw) * 4;
				switch (mode) {
					case 0:
						for (i = 0; i < 4; ++i) {
							p1 = _FullTree->getCode(bs);
							p2 = _FullTree->getCode(bs);
							for (j = 0; j < doubleY; ++j) {
								out[2] = p1 & 0xff;
								out[3] = p1 >> 8;
								out[0] = p2 & 0xff;
								out[1] = p2 >> 8;
								out += stride;
							}
						}
						break;
					case 1:
						p1 = _FullTree->getCode(bs);
						out[0] = out[1] = p1 & 0xFF;
						out[2] = out[3] = p1 >> 8;
						out += stride;
						out[0] = out[1] = p1 & 0xFF;
						out[2] = out[3] = p1 >> 8;
						out += stride;
						p2 = _FullTree->getCode(bs);
						out[0] = out[1] = p2 & 0xFF;
						out[2] = out[3] = p2 >> 8;
						out += stride;
						out[0] = out[1] = p2 & 0xFF;
						out[2] = out[3] = p2 >> 8;
						out += stride;
						break;
					case 2:
						for (i = 0; i < 2; i++) {
							// We first get p2 and then p1
							// Check ffmpeg thread "[PATCH] Smacker video decoder bug fix"
							// http://article.gmane.org/gmane.comp.video.ffmpeg.devel/78768
							p2 = _FullTree->getCode(bs);
							p1 = _FullTree->getCode(bs);
							for (j = 0; j < doubleY; ++j) {
								out[0] = p1 & 0xff;
								out[1] = p1 >> 8;
								out[2] = p2 & 0xff;
								out[3] = p2 >> 8;
								out += stride;
							}
							for (j = 0; j < doubleY; ++j) {
								out[0] = p1 & 0xff;
								out[1] = p1 >> 8;
								out[2] = p2 & 0xff;
								out[3] = p2 >> 8;
								out += stride;
							}
						}
						break;
				}
				++block;
			}
			break;
		case SMK_BLOCK_SKIP:
			while (run-- && block < blocks)
				block++;
			break;
		case SMK_BLOCK_FILL:
			uint32 col;
			mode = type >> 8;
			while (run-- && block < blocks) {
				out = _videoFrameBuffer + (block / bw) * (stride * 4 * doubleY) + (block % bw) * 4;
				col = mode * 0x01010101;
				for (i = 0; i < 4 * doubleY; ++i) {
					out[0] = out[1] = out[2] = out[3] = col;
					out += stride;
				}
				++block;
			}
			break;
		}
	}

	_fileStream->seek(startPos + frameSize);

	free(_frameData);

	return ++_videoInfo.currentFrame < _videoInfo.frameCount;
}

void SmackerDecoder::queueCompressedBuffer(byte *buffer, uint32 bufferSize,
		uint32 unpackedSize, int streamNum) {

	BitStream audioBS(buffer, bufferSize);
	bool dataPresent = audioBS.getBit();

	if (!dataPresent)
		return;

	bool isStereo = audioBS.getBit();
	assert(isStereo == _header.audioInfo[streamNum].isStereo);
	bool is16Bits = audioBS.getBit();
	assert(is16Bits == _header.audioInfo[streamNum].is16Bits);

	int numBytes = 1 * (isStereo ? 2 : 1) * (is16Bits ? 2 : 1);

	byte *unpackedBuffer = new byte[unpackedSize];
	byte *curPointer = unpackedBuffer;
	uint32 curPos = 0;

	SmallHuffmanTree *audioTrees[4];
	for (int k = 0; k < numBytes; k++)
		audioTrees[k] = new SmallHuffmanTree(audioBS);

	// Base values, stored as big endian

	int32 bases[2];

	if (isStereo)
		bases[1] = (!is16Bits) ?   audioBS.getBits8() :
		               ((int16) (((audioBS.getBits8() << 8) | audioBS.getBits8())));

	bases[0] = (!is16Bits) ?   audioBS.getBits8() :
	               ((int16) (((audioBS.getBits8() << 8) | audioBS.getBits8())));


	// The bases are the first samples, too
	for (int i = 0; i < (isStereo ? 2 : 1); i++, curPointer += (is16Bits ? 2 : 1), curPos += (is16Bits ? 2 : 1)) {
		if (is16Bits)
			WRITE_BE_UINT16(curPointer, bases[i]);
		else
			*curPointer = (bases[i] & 0xFF) ^ 0x80;
	}

	// Next follow the deltas, which are added to the corresponding base values and
	// are stored as little endian
	// We store the unpacked bytes in big endian format

	while (curPos < unpackedSize) {
		// If the sample is stereo, the data is stored for the left and right channel, respectively
		// (the exact opposite to the base values)
		if (!is16Bits) {

			for (int k = 0; k < (isStereo ? 2 : 1); k++) {
				bases[k] += (int8) ((int16) audioTrees[k]->getCode(audioBS));
				*curPointer++ = CLIP<int>(bases[k], 0, 255) ^ 0x80;
				curPos++;
			}

		} else {

			for (int k = 0; k < (isStereo ? 2 : 1); k++) {
				bases[k] += (int16) (audioTrees[k * 2]->getCode(audioBS) |
				                    (audioTrees[k * 2 + 1]->getCode(audioBS) << 8));

				WRITE_BE_UINT16(curPointer, CLIP<int32>(bases[k], -32768, 32767));
				curPointer += 2;
				curPos += 2;
			}
		}

	}

	for (int k = 0; k < numBytes; k++)
		delete audioTrees[k];

	_audioStream->queueBuffer(unpackedBuffer, unpackedSize);
	// unpackedBuffer will be deleted by AppendableAudioStream
}

void SmackerDecoder::unpackPalette() {
	uint startPos = _fileStream->pos();
	uint32 len = 4 * _fileStream->readByte();

	byte *chunk = (byte *)malloc(len);
	_fileStream->read(&chunk[0], len);
	byte *p = &chunk[0];

	byte oldPalette[3*256];
	memcpy(oldPalette, _palette, 3 * 256);

	byte *pal = _palette;

	int sz = 0;
	byte b0;
	while (sz < 256) {
		b0 = *p++;
		if (b0 & 0x80) {               // if top bit is 1 (0x80 = 10000000)
			sz += (b0 & 0x7f) + 1;     // get lower 7 bits + 1 (0x7f = 01111111)
			pal += 3 * ((b0 & 0x7f) + 1);
		} else if (b0 & 0x40) {        // if top 2 bits are 01 (0x40 = 01000000)
			byte c = (b0 & 0x3f) + 1;  // get lower 6 bits + 1 (0x3f = 00111111)
			uint s = 3 * *p++;
			sz += c;

			while (c--) {
				*pal++ = oldPalette[s + 0];
				*pal++ = oldPalette[s + 1];
				*pal++ = oldPalette[s + 2];
				s += 3;
			}
		} else {                       // top 2 bits are 00
			sz++;
			// get the lower 6 bits for each component (0x3f = 00111111)
			byte b = b0 & 0x3f;
			byte g = (*p++) & 0x3f;
			byte r = (*p++) & 0x3f;

			assert(g < 0xc0 && b < 0xc0);

			// upscale to full 8-bit color values by multiplying by 4
			*pal++ = b * 4;
			*pal++ = g * 4;
			*pal++ = r * 4;
		}
	}

	_fileStream->seek(startPos + len);

	free(chunk);
}

} // End of namespace Graphics