Free Electrons

Embedded Linux Experts

  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
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
/* Linux driver for Philips webcam
   Decompression for chipset version 2 et 3
   (C) 2004-2006  Luc Saillard (luc@saillard.org)

   NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx
   driver and thus may have bugs that are not present in the original version.
   Please send bug reports and support requests to <luc@saillard.org>.
   The decompression routines have been implemented by reverse-engineering the
   Nemosoft binary pwcx module. Caveat emptor.

   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

*/

#include "pwc-timon.h"
#include "pwc-kiara.h"
#include "pwc-dec23.h"
#include <media/pwc-ioctl.h>

#include <linux/string.h>
#include <linux/slab.h>

/*
 * USE_LOOKUP_TABLE_TO_CLAMP
 *   0: use a C version of this tests:  {  a<0?0:(a>255?255:a) }
 *   1: use a faster lookup table for cpu with a big cache (intel)
 */
#define USE_LOOKUP_TABLE_TO_CLAMP	1
/*
 * UNROLL_LOOP_FOR_COPYING_BLOCK
 *   0: use a loop for a smaller code (but little slower)
 *   1: when unrolling the loop, gcc produces some faster code (perhaps only
 *   valid for intel processor class). Activating this option, automaticaly
 *   activate USE_LOOKUP_TABLE_TO_CLAMP
 */
#define UNROLL_LOOP_FOR_COPY		1
#if UNROLL_LOOP_FOR_COPY
# undef USE_LOOKUP_TABLE_TO_CLAMP
# define USE_LOOKUP_TABLE_TO_CLAMP 1
#endif

/*
 * ENABLE_BAYER_DECODER
 *   0: bayer decoder is not build (save some space)
 *   1: bayer decoder is build and can be used
 */
#define ENABLE_BAYER_DECODER 0

static void build_subblock_pattern(struct pwc_dec23_private *pdec)
{
	static const unsigned int initial_values[12] = {
		-0x526500, -0x221200, 0x221200, 0x526500,
			   -0x3de200, 0x3de200,
		-0x6db480, -0x2d5d00, 0x2d5d00, 0x6db480,
			   -0x12c200, 0x12c200

	};
	static const unsigned int values_derivated[12] = {
		0xa4ca, 0x4424, -0x4424, -0xa4ca,
			0x7bc4, -0x7bc4,
		0xdb69, 0x5aba, -0x5aba, -0xdb69,
			0x2584, -0x2584
	};
	unsigned int temp_values[12];
	int i, j;

	memcpy(temp_values, initial_values, sizeof(initial_values));
	for (i = 0; i < 256; i++) {
		for (j = 0; j < 12; j++) {
			pdec->table_subblock[i][j] = temp_values[j];
			temp_values[j] += values_derivated[j];
		}
	}
}

static void build_bit_powermask_table(struct pwc_dec23_private *pdec)
{
	unsigned char *p;
	unsigned int bit, byte, mask, val;
	unsigned int bitpower = 1;

	for (bit = 0; bit < 8; bit++) {
		mask = bitpower - 1;
		p = pdec->table_bitpowermask[bit];
		for (byte = 0; byte < 256; byte++) {
			val = (byte & mask);
			if (byte & bitpower)
				val = -val;
			*p++ = val;
		}
		bitpower<<=1;
	}
}


static void build_table_color(const unsigned int romtable[16][8],
			      unsigned char p0004[16][1024],
			      unsigned char p8004[16][256])
{
	int compression_mode, j, k, bit, pw;
	unsigned char *p0, *p8;
	const unsigned int *r;

	/* We have 16 compressions tables */
	for (compression_mode = 0; compression_mode < 16; compression_mode++) {
		p0 = p0004[compression_mode];
		p8 = p8004[compression_mode];
		r  = romtable[compression_mode];

		for (j = 0; j < 8; j++, r++, p0 += 128) {

			for (k = 0; k < 16; k++) {
				if (k == 0)
					bit = 1;
				else if (k >= 1 && k < 3)
					bit = (r[0] >> 15) & 7;
				else if (k >= 3 && k < 6)
					bit = (r[0] >> 12) & 7;
				else if (k >= 6 && k < 10)
					bit = (r[0] >> 9) & 7;
				else if (k >= 10 && k < 13)
					bit = (r[0] >> 6) & 7;
				else if (k >= 13 && k < 15)
					bit = (r[0] >> 3) & 7;
				else
					bit = (r[0]) & 7;
				if (k == 0)
					*p8++ = 8;
				else
					*p8++ = j - bit;
				*p8++ = bit;

				pw = 1 << bit;
				p0[k + 0x00] = (1 * pw) + 0x80;
				p0[k + 0x10] = (2 * pw) + 0x80;
				p0[k + 0x20] = (3 * pw) + 0x80;
				p0[k + 0x30] = (4 * pw) + 0x80;
				p0[k + 0x40] = (-1 * pw) + 0x80;
				p0[k + 0x50] = (-2 * pw) + 0x80;
				p0[k + 0x60] = (-3 * pw) + 0x80;
				p0[k + 0x70] = (-4 * pw) + 0x80;
			}	/* end of for (k=0; k<16; k++, p8++) */
		}	/* end of for (j=0; j<8; j++ , table++) */
	} /* end of foreach compression_mode */
}

/*
 *
 */
static void fill_table_dc00_d800(struct pwc_dec23_private *pdec)
{
#define SCALEBITS 15
#define ONE_HALF  (1UL << (SCALEBITS - 1))
	int i;
	unsigned int offset1 = ONE_HALF;
	unsigned int offset2 = 0x0000;

	for (i=0; i<256; i++) {
		pdec->table_dc00[i] = offset1 & ~(ONE_HALF);
		pdec->table_d800[i] = offset2;

		offset1 += 0x7bc4;
		offset2 += 0x7bc4;
	}
}

/*
 * To decode the stream:
 *   if look_bits(2) == 0:	# op == 2 in the lookup table
 *      skip_bits(2)
 *      end of the stream
 *   elif look_bits(3) == 7:	# op == 1 in the lookup table
 *      skip_bits(3)
 *      yyyy = get_bits(4)
 *      xxxx = get_bits(8)
 *   else:			# op == 0 in the lookup table
 *      skip_bits(x)
 *
 * For speedup processing, we build a lookup table and we takes the first 6 bits.
 *
 * struct {
 *   unsigned char op;	    // operation to execute
 *   unsigned char bits;    // bits use to perform operation
 *   unsigned char offset1; // offset to add to access in the table_0004 % 16
 *   unsigned char offset2; // offset to add to access in the table_0004
 * }
 *
 * How to build this table ?
 *   op == 2 when (i%4)==0
 *   op == 1 when (i%8)==7
 *   op == 0 otherwise
 *
 */
static const unsigned char hash_table_ops[64*4] = {
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x10,
	0x00, 0x06, 0x01, 0x30,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x01, 0x20,
	0x01, 0x00, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x50,
	0x00, 0x05, 0x02, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x03, 0x00,
	0x01, 0x00, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x10,
	0x00, 0x06, 0x02, 0x10,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x01, 0x60,
	0x01, 0x00, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x50,
	0x00, 0x05, 0x02, 0x40,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x03, 0x40,
	0x01, 0x00, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x10,
	0x00, 0x06, 0x01, 0x70,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x01, 0x20,
	0x01, 0x00, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x50,
	0x00, 0x05, 0x02, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x03, 0x00,
	0x01, 0x00, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x10,
	0x00, 0x06, 0x02, 0x50,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x01, 0x60,
	0x01, 0x00, 0x00, 0x00,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x00,
	0x00, 0x04, 0x01, 0x50,
	0x00, 0x05, 0x02, 0x40,
	0x02, 0x00, 0x00, 0x00,
	0x00, 0x03, 0x01, 0x40,
	0x00, 0x05, 0x03, 0x40,
	0x01, 0x00, 0x00, 0x00
};

/*
 *
 */
static const unsigned int MulIdx[16][16] = {
	{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,},
	{0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3,},
	{0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,},
	{4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 4, 4,},
	{6, 7, 8, 9, 7, 10, 11, 8, 8, 11, 10, 7, 9, 8, 7, 6,},
	{4, 5, 5, 4, 4, 5, 5, 4, 4, 5, 5, 4, 4, 5, 5, 4,},
	{1, 3, 0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3, 0, 2,},
	{0, 3, 3, 0, 1, 2, 2, 1, 2, 1, 1, 2, 3, 0, 0, 3,},
	{0, 1, 2, 3, 3, 2, 1, 0, 3, 2, 1, 0, 0, 1, 2, 3,},
	{1, 1, 1, 1, 3, 3, 3, 3, 0, 0, 0, 0, 2, 2, 2, 2,},
	{7, 10, 11, 8, 9, 8, 7, 6, 6, 7, 8, 9, 8, 11, 10, 7,},
	{4, 5, 5, 4, 5, 4, 4, 5, 5, 4, 4, 5, 4, 5, 5, 4,},
	{7, 9, 6, 8, 10, 8, 7, 11, 11, 7, 8, 10, 8, 6, 9, 7,},
	{1, 3, 0, 2, 2, 0, 3, 1, 2, 0, 3, 1, 1, 3, 0, 2,},
	{1, 2, 2, 1, 3, 0, 0, 3, 0, 3, 3, 0, 2, 1, 1, 2,},
	{10, 8, 7, 11, 8, 6, 9, 7, 7, 9, 6, 8, 11, 7, 8, 10}
};

#if USE_LOOKUP_TABLE_TO_CLAMP
#define MAX_OUTER_CROP_VALUE	(512)
static unsigned char pwc_crop_table[256 + 2*MAX_OUTER_CROP_VALUE];
#define CLAMP(x) (pwc_crop_table[MAX_OUTER_CROP_VALUE+(x)])
#else
#define CLAMP(x) ((x)>255?255:((x)<0?0:x))
#endif


/* If the type or the command change, we rebuild the lookup table */
int pwc_dec23_init(struct pwc_device *pwc, int type, unsigned char *cmd)
{
	int flags, version, shift, i;
	struct pwc_dec23_private *pdec;

	if (pwc->decompress_data == NULL) {
		pdec = kmalloc(sizeof(struct pwc_dec23_private), GFP_KERNEL);
		if (pdec == NULL)
			return -ENOMEM;
		pwc->decompress_data = pdec;
	}
	pdec = pwc->decompress_data;

	if (DEVICE_USE_CODEC3(type)) {
		flags = cmd[2] & 0x18;
		if (flags == 8)
			pdec->nbits = 7;	/* More bits, mean more bits to encode the stream, but better quality */
		else if (flags == 0x10)
			pdec->nbits = 8;
		else
			pdec->nbits = 6;

		version = cmd[2] >> 5;
		build_table_color(KiaraRomTable[version][0], pdec->table_0004_pass1, pdec->table_8004_pass1);
		build_table_color(KiaraRomTable[version][1], pdec->table_0004_pass2, pdec->table_8004_pass2);

	} else {

		flags = cmd[2] & 6;
		if (flags == 2)
			pdec->nbits = 7;
		else if (flags == 4)
			pdec->nbits = 8;
		else
			pdec->nbits = 6;

		version = cmd[2] >> 3;
		build_table_color(TimonRomTable[version][0], pdec->table_0004_pass1, pdec->table_8004_pass1);
		build_table_color(TimonRomTable[version][1], pdec->table_0004_pass2, pdec->table_8004_pass2);
	}

	/* Informations can be coded on a variable number of bits but never less than 8 */
	shift = 8 - pdec->nbits;
	pdec->scalebits = SCALEBITS - shift;
	pdec->nbitsmask = 0xFF >> shift;

	fill_table_dc00_d800(pdec);
	build_subblock_pattern(pdec);
	build_bit_powermask_table(pdec);

#if USE_LOOKUP_TABLE_TO_CLAMP
	/* Build the static table to clamp value [0-255] */
	for (i=0;i<MAX_OUTER_CROP_VALUE;i++)
		pwc_crop_table[i] = 0;
	for (i=0; i<256; i++)
		pwc_crop_table[MAX_OUTER_CROP_VALUE+i] = i;
	for (i=0; i<MAX_OUTER_CROP_VALUE; i++)
		pwc_crop_table[MAX_OUTER_CROP_VALUE+256+i] = 255;
#endif

	return 0;
}

/*
 * Copy the 4x4 image block to Y plane buffer
 */
static void copy_image_block_Y(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
{
#if UNROLL_LOOP_FOR_COPY
	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
	const int *c = src;
	unsigned char *d = dst;

	*d++ = cm[c[0] >> scalebits];
	*d++ = cm[c[1] >> scalebits];
	*d++ = cm[c[2] >> scalebits];
	*d++ = cm[c[3] >> scalebits];

	d = dst + bytes_per_line;
	*d++ = cm[c[4] >> scalebits];
	*d++ = cm[c[5] >> scalebits];
	*d++ = cm[c[6] >> scalebits];
	*d++ = cm[c[7] >> scalebits];

	d = dst + bytes_per_line*2;
	*d++ = cm[c[8] >> scalebits];
	*d++ = cm[c[9] >> scalebits];
	*d++ = cm[c[10] >> scalebits];
	*d++ = cm[c[11] >> scalebits];

	d = dst + bytes_per_line*3;
	*d++ = cm[c[12] >> scalebits];
	*d++ = cm[c[13] >> scalebits];
	*d++ = cm[c[14] >> scalebits];
	*d++ = cm[c[15] >> scalebits];
#else
	int i;
	const int *c = src;
	unsigned char *d = dst;
	for (i = 0; i < 4; i++, c++)
		*d++ = CLAMP((*c) >> scalebits);

	d = dst + bytes_per_line;
	for (i = 0; i < 4; i++, c++)
		*d++ = CLAMP((*c) >> scalebits);

	d = dst + bytes_per_line*2;
	for (i = 0; i < 4; i++, c++)
		*d++ = CLAMP((*c) >> scalebits);

	d = dst + bytes_per_line*3;
	for (i = 0; i < 4; i++, c++)
		*d++ = CLAMP((*c) >> scalebits);
#endif
}

/*
 * Copy the 4x4 image block to a CrCb plane buffer
 *
 */
static void copy_image_block_CrCb(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
{
#if UNROLL_LOOP_FOR_COPY
	/* Unroll all loops */
	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
	const int *c = src;
	unsigned char *d = dst;

	*d++ = cm[c[0] >> scalebits];
	*d++ = cm[c[4] >> scalebits];
	*d++ = cm[c[1] >> scalebits];
	*d++ = cm[c[5] >> scalebits];
	*d++ = cm[c[2] >> scalebits];
	*d++ = cm[c[6] >> scalebits];
	*d++ = cm[c[3] >> scalebits];
	*d++ = cm[c[7] >> scalebits];

	d = dst + bytes_per_line;
	*d++ = cm[c[12] >> scalebits];
	*d++ = cm[c[8] >> scalebits];
	*d++ = cm[c[13] >> scalebits];
	*d++ = cm[c[9] >> scalebits];
	*d++ = cm[c[14] >> scalebits];
	*d++ = cm[c[10] >> scalebits];
	*d++ = cm[c[15] >> scalebits];
	*d++ = cm[c[11] >> scalebits];
#else
	int i;
	const int *c1 = src;
	const int *c2 = src + 4;
	unsigned char *d = dst;

	for (i = 0; i < 4; i++, c1++, c2++) {
		*d++ = CLAMP((*c1) >> scalebits);
		*d++ = CLAMP((*c2) >> scalebits);
	}
	c1 = src + 12;
	d = dst + bytes_per_line;
	for (i = 0; i < 4; i++, c1++, c2++) {
		*d++ = CLAMP((*c1) >> scalebits);
		*d++ = CLAMP((*c2) >> scalebits);
	}
#endif
}

#if ENABLE_BAYER_DECODER
/*
 * Format: 8x2 pixels
 *   . G . G . G . G . G . G . G
 *   . . . . . . . . . . . . . .
 *   . G . G . G . G . G . G . G
 *   . . . . . . . . . . . . . .
 *   or
 *   . . . . . . . . . . . . . .
 *   G . G . G . G . G . G . G .
 *   . . . . . . . . . . . . . .
 *   G . G . G . G . G . G . G .
*/
static void copy_image_block_Green(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
{
#if UNROLL_LOOP_FOR_COPY
	/* Unroll all loops */
	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
	unsigned char *d = dst;
	const int *c = src;

	d[0] = cm[c[0] >> scalebits];
	d[2] = cm[c[1] >> scalebits];
	d[4] = cm[c[2] >> scalebits];
	d[6] = cm[c[3] >> scalebits];
	d[8] = cm[c[4] >> scalebits];
	d[10] = cm[c[5] >> scalebits];
	d[12] = cm[c[6] >> scalebits];
	d[14] = cm[c[7] >> scalebits];

	d = dst + bytes_per_line;
	d[0] = cm[c[8] >> scalebits];
	d[2] = cm[c[9] >> scalebits];
	d[4] = cm[c[10] >> scalebits];
	d[6] = cm[c[11] >> scalebits];
	d[8] = cm[c[12] >> scalebits];
	d[10] = cm[c[13] >> scalebits];
	d[12] = cm[c[14] >> scalebits];
	d[14] = cm[c[15] >> scalebits];
#else
	int i;
	unsigned char *d;
	const int *c = src;

	d = dst;
	for (i = 0; i < 8; i++, c++)
		d[i*2] = CLAMP((*c) >> scalebits);

	d = dst + bytes_per_line;
	for (i = 0; i < 8; i++, c++)
		d[i*2] = CLAMP((*c) >> scalebits);
#endif
}
#endif

#if ENABLE_BAYER_DECODER
/*
 * Format: 4x4 pixels
 *   R . R . R . R
 *   . B . B . B .
 *   R . R . R . R
 *   . B . B . B .
 */
static void copy_image_block_RedBlue(const int *src, unsigned char *dst, unsigned int bytes_per_line, unsigned int scalebits)
{
#if UNROLL_LOOP_FOR_COPY
	/* Unroll all loops */
	const unsigned char *cm = pwc_crop_table+MAX_OUTER_CROP_VALUE;
	unsigned char *d = dst;
	const int *c = src;

	d[0] = cm[c[0] >> scalebits];
	d[2] = cm[c[1] >> scalebits];
	d[4] = cm[c[2] >> scalebits];
	d[6] = cm[c[3] >> scalebits];

	d = dst + bytes_per_line;
	d[1] = cm[c[4] >> scalebits];
	d[3] = cm[c[5] >> scalebits];
	d[5] = cm[c[6] >> scalebits];
	d[7] = cm[c[7] >> scalebits];

	d = dst + bytes_per_line*2;
	d[0] = cm[c[8] >> scalebits];
	d[2] = cm[c[9] >> scalebits];
	d[4] = cm[c[10] >> scalebits];
	d[6] = cm[c[11] >> scalebits];

	d = dst + bytes_per_line*3;
	d[1] = cm[c[12] >> scalebits];
	d[3] = cm[c[13] >> scalebits];
	d[5] = cm[c[14] >> scalebits];
	d[7] = cm[c[15] >> scalebits];
#else
	int i;
	unsigned char *d;
	const int *c = src;

	d = dst;
	for (i = 0; i < 4; i++, c++)
		d[i*2] = CLAMP((*c) >> scalebits);

	d = dst + bytes_per_line;
	for (i = 0; i < 4; i++, c++)
		d[i*2+1] = CLAMP((*c) >> scalebits);

	d = dst + bytes_per_line*2;
	for (i = 0; i < 4; i++, c++)
		d[i*2] = CLAMP((*c) >> scalebits);

	d = dst + bytes_per_line*3;
	for (i = 0; i < 4; i++, c++)
		d[i*2+1] = CLAMP((*c) >> scalebits);
#endif
}
#endif

/*
 * To manage the stream, we keep bits in a 32 bits register.
 * fill_nbits(n): fill the reservoir with at least n bits
 * skip_bits(n): discard n bits from the reservoir
 * get_bits(n): fill the reservoir, returns the first n bits and discard the
 *              bits from the reservoir.
 * __get_nbits(n): faster version of get_bits(n), but asumes that the reservoir
 *                 contains at least n bits. bits returned is discarded.
 */
#define fill_nbits(pdec, nbits_wanted) do { \
   while (pdec->nbits_in_reservoir<(nbits_wanted)) \
    { \
      pdec->reservoir |= (*(pdec->stream)++) << (pdec->nbits_in_reservoir); \
      pdec->nbits_in_reservoir += 8; \
    } \
}  while(0);

#define skip_nbits(pdec, nbits_to_skip) do { \
   pdec->reservoir >>= (nbits_to_skip); \
   pdec->nbits_in_reservoir -= (nbits_to_skip); \
}  while(0);

#define get_nbits(pdec, nbits_wanted, result) do { \
   fill_nbits(pdec, nbits_wanted); \
   result = (pdec->reservoir) & ((1U<<(nbits_wanted))-1); \
   skip_nbits(pdec, nbits_wanted); \
}  while(0);

#define __get_nbits(pdec, nbits_wanted, result) do { \
   result = (pdec->reservoir) & ((1U<<(nbits_wanted))-1); \
   skip_nbits(pdec, nbits_wanted); \
}  while(0);

#define look_nbits(pdec, nbits_wanted) \
   ((pdec->reservoir) & ((1U<<(nbits_wanted))-1))

/*
 * Decode a 4x4 pixel block
 */
static void decode_block(struct pwc_dec23_private *pdec,
			 const unsigned char *ptable0004,
			 const unsigned char *ptable8004)
{
	unsigned int primary_color;
	unsigned int channel_v, offset1, op;
	int i;

	fill_nbits(pdec, 16);
	__get_nbits(pdec, pdec->nbits, primary_color);

	if (look_nbits(pdec,2) == 0) {
		skip_nbits(pdec, 2);
		/* Very simple, the color is the same for all pixels of the square */
		for (i = 0; i < 16; i++)
			pdec->temp_colors[i] = pdec->table_dc00[primary_color];

		return;
	}

	/* This block is encoded with small pattern */
	for (i = 0; i < 16; i++)
		pdec->temp_colors[i] = pdec->table_d800[primary_color];

	__get_nbits(pdec, 3, channel_v);
	channel_v = ((channel_v & 1) << 2) | (channel_v & 2) | ((channel_v & 4) >> 2);

	ptable0004 += (channel_v * 128);
	ptable8004 += (channel_v * 32);

	offset1 = 0;
	do
	{
		unsigned int htable_idx, rows = 0;
		const unsigned int *block;

		/* [  zzzz y x x ]
		 *     xx == 00 :=> end of the block def, remove the two bits from the stream
		 *    yxx == 111
		 *    yxx == any other value
		 *
		 */
		fill_nbits(pdec, 16);
		htable_idx = look_nbits(pdec, 6);
		op = hash_table_ops[htable_idx * 4];

		if (op == 2) {
			skip_nbits(pdec, 2);

		} else if (op == 1) {
			/* 15bits [ xxxx xxxx yyyy 111 ]
			 * yyy => offset in the table8004
			 * xxx => offset in the tabled004 (tree)
			 */
			unsigned int mask, shift;
			unsigned int nbits, col1;
			unsigned int yyyy;

			skip_nbits(pdec, 3);
			/* offset1 += yyyy */
			__get_nbits(pdec, 4, yyyy);
			offset1 += 1 + yyyy;
			offset1 &= 0x0F;
			nbits = ptable8004[offset1 * 2];

			/* col1 = xxxx xxxx */
			__get_nbits(pdec, nbits+1, col1);

			/* Bit mask table */
			mask = pdec->table_bitpowermask[nbits][col1];
			shift = ptable8004[offset1 * 2 + 1];
			rows = ((mask << shift) + 0x80) & 0xFF;

			block = pdec->table_subblock[rows];
			for (i = 0; i < 16; i++)
				pdec->temp_colors[i] += block[MulIdx[offset1][i]];

		} else {
			/* op == 0
			 * offset1 is coded on 3 bits
			 */
			unsigned int shift;

			offset1 += hash_table_ops [htable_idx * 4 + 2];
			offset1 &= 0x0F;

			rows = ptable0004[offset1 + hash_table_ops [htable_idx * 4 + 3]];
			block = pdec->table_subblock[rows];
			for (i = 0; i < 16; i++)
				pdec->temp_colors[i] += block[MulIdx[offset1][i]];

			shift = hash_table_ops[htable_idx * 4 + 1];
			skip_nbits(pdec, shift);
		}

	} while (op != 2);

}

static void DecompressBand23(struct pwc_dec23_private *pdec,
			     const unsigned char *rawyuv,
			     unsigned char *planar_y,
			     unsigned char *planar_u,
			     unsigned char *planar_v,
			     unsigned int   compressed_image_width,
			     unsigned int   real_image_width)
{
	int compression_index, nblocks;
	const unsigned char *ptable0004;
	const unsigned char *ptable8004;

	pdec->reservoir = 0;
	pdec->nbits_in_reservoir = 0;
	pdec->stream = rawyuv + 1;	/* The first byte of the stream is skipped */

	get_nbits(pdec, 4, compression_index);

	/* pass 1: uncompress Y component */
	nblocks = compressed_image_width / 4;

	ptable0004 = pdec->table_0004_pass1[compression_index];
	ptable8004 = pdec->table_8004_pass1[compression_index];

	/* Each block decode a square of 4x4 */
	while (nblocks) {
		decode_block(pdec, ptable0004, ptable8004);
		copy_image_block_Y(pdec->temp_colors, planar_y, real_image_width, pdec->scalebits);
		planar_y += 4;
		nblocks--;
	}

	/* pass 2: uncompress UV component */
	nblocks = compressed_image_width / 8;

	ptable0004 = pdec->table_0004_pass2[compression_index];
	ptable8004 = pdec->table_8004_pass2[compression_index];

	/* Each block decode a square of 4x4 */
	while (nblocks) {
		decode_block(pdec, ptable0004, ptable8004);
		copy_image_block_CrCb(pdec->temp_colors, planar_u, real_image_width/2, pdec->scalebits);

		decode_block(pdec, ptable0004, ptable8004);
		copy_image_block_CrCb(pdec->temp_colors, planar_v, real_image_width/2, pdec->scalebits);

		planar_v += 8;
		planar_u += 8;
		nblocks -= 2;
	}

}

#if ENABLE_BAYER_DECODER
/*
 * Size need to be a multiple of 8 in width
 *
 * Return a block of four line encoded like this:
 *
 *   G R G R G R G R G R G R G R G R
 *   B G B G B G B G B G B G B G B G
 *   G R G R G R G R G R G R G R G R
 *   B G B G B G B G B G B G B G B G
 *
 */
static void DecompressBandBayer(struct pwc_dec23_private *pdec,
				const unsigned char *rawyuv,
				unsigned char *rgbbayer,
				unsigned int   compressed_image_width,
				unsigned int   real_image_width)
{
	int compression_index, nblocks;
	const unsigned char *ptable0004;
	const unsigned char *ptable8004;
	unsigned char *dest;

	pdec->reservoir = 0;
	pdec->nbits_in_reservoir = 0;
	pdec->stream = rawyuv + 1;	/* The first byte of the stream is skipped */

	get_nbits(pdec, 4, compression_index);

	/* pass 1: uncompress RB component */
	nblocks = compressed_image_width / 4;

	ptable0004 = pdec->table_0004_pass1[compression_index];
	ptable8004 = pdec->table_8004_pass1[compression_index];
	dest = rgbbayer;

	/* Each block decode a square of 4x4 */
	while (nblocks) {
		decode_block(pdec, ptable0004, ptable8004);
		copy_image_block_RedBlue(pdec->temp_colors, rgbbayer, real_image_width, pdec->scalebits);
		dest += 8;
		nblocks--;
	}

	/* pass 2: uncompress G component */
	nblocks = compressed_image_width / 8;

	ptable0004 = pdec->table_0004_pass2[compression_index];
	ptable8004 = pdec->table_8004_pass2[compression_index];

	/* Each block decode a square of 4x4 */
	while (nblocks) {
		decode_block(pdec, ptable0004, ptable8004);
		copy_image_block_Green(pdec->temp_colors, rgbbayer+1, real_image_width, pdec->scalebits);

		decode_block(pdec, ptable0004, ptable8004);
		copy_image_block_Green(pdec->temp_colors, rgbbayer+real_image_width, real_image_width, pdec->scalebits);

		rgbbayer += 16;
		nblocks -= 2;
	}
}
#endif


/**
 *
 * Uncompress a pwc23 buffer.
 *
 * pwc.view: size of the image wanted
 * pwc.image: size of the image returned by the camera
 * pwc.offset: (x,y) to displayer image in the view
 *
 * src: raw data
 * dst: image output
 * flags: PWCX_FLAG_PLANAR or PWCX_FLAG_BAYER
 */
void pwc_dec23_decompress(const struct pwc_device *pwc,
			  const void *src,
			  void *dst,
			  int flags)
{
	int bandlines_left, stride, bytes_per_block;

	bandlines_left = pwc->image.y / 4;
	bytes_per_block = pwc->view.x * 4;

	if (flags & PWCX_FLAG_BAYER) {
#if ENABLE_BAYER_DECODER
		/* RGB Bayer format */
		unsigned char *rgbout;

		stride = pwc->view.x * pwc->offset.y;
		rgbout = dst + stride + pwc->offset.x;


		while (bandlines_left--) {

			DecompressBandBayer(pwc->decompress_data,
					    src,
					    rgbout,
					    pwc->image.x, pwc->view.x);

			src += pwc->vbandlength;
			rgbout += bytes_per_block;

		}
#else
		memset(dst, 0, pwc->view.x * pwc->view.y);
#endif

	} else {
		/* YUV420P image format */
		unsigned char *pout_planar_y;
		unsigned char *pout_planar_u;
		unsigned char *pout_planar_v;
		unsigned int   plane_size;

		plane_size = pwc->view.x * pwc->view.y;

		/* offset in Y plane */
		stride = pwc->view.x * pwc->offset.y;
		pout_planar_y = dst + stride + pwc->offset.x;

		/* offsets in U/V planes */
		stride = (pwc->view.x * pwc->offset.y) / 4 + pwc->offset.x / 2;
		pout_planar_u = dst + plane_size + stride;
		pout_planar_v = dst + plane_size + plane_size / 4 + stride;

		while (bandlines_left--) {

			DecompressBand23(pwc->decompress_data,
					 src,
					 pout_planar_y, pout_planar_u, pout_planar_v,
					 pwc->image.x, pwc->view.x);
			src += pwc->vbandlength;
			pout_planar_y += bytes_per_block;
			pout_planar_u += pwc->view.x;
			pout_planar_v += pwc->view.x;

		}

	}

}

void pwc_dec23_exit(void)
{
	/* Do nothing */

}

/**
 * Allocate a private structure used by lookup table.
 * You must call kfree() to free the memory allocated.
 */
int pwc_dec23_alloc(struct pwc_device *pwc)
{
	pwc->decompress_data = kmalloc(sizeof(struct pwc_dec23_private), GFP_KERNEL);
	if (pwc->decompress_data == NULL)
		return -ENOMEM;
	return 0;
}

/* vim: set cino= formatoptions=croql cindent shiftwidth=8 tabstop=8: */