fix decoder so that ffmpeg does not crash, at least not right away
[libav.git] / libavcodec / vp3.c
1 /*
2 *
3 * Copyright (C) 2003 the ffmpeg project
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 * VP3 Video Decoder by Mike Melanson (melanson@pcisys.net)
20 *
21 */
22
23 /**
24 * @file vp3.c
25 * On2 VP3 Video Decoder
26 */
27
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32
33 #include "common.h"
34 #include "avcodec.h"
35 #include "dsputil.h"
36 #include "mpegvideo.h"
37 #include "dsputil.h"
38 #include "bswap.h"
39
40 #include "vp3data.h"
41
42 #define FRAGMENT_PIXELS 8
43
44 /*
45 * Debugging Variables
46 *
47 * Define one or more of the following compile-time variables to 1 to obtain
48 * elaborate information about certain aspects of the decoding process.
49 *
50 * DEBUG_VP3: high-level decoding flow
51 * DEBUG_INIT: initialization parameters
52 * DEBUG_DEQUANTIZERS: display how the dequanization tables are built
53 * DEBUG_BLOCK_CODING: unpacking the superblock/macroblock/fragment coding
54 * DEBUG_MODES: unpacking the coding modes for individual fragments
55 * DEBUG_VECTORS: display the motion vectors
56 * DEBUG_TOKEN: display exhaustive information about each DCT token
57 * DEBUG_VLC: display the VLCs as they are extracted from the stream
58 * DEBUG_DC_PRED: display the process of reversing DC prediction
59 * DEBUG_IDCT: show every detail of the IDCT process
60 */
61
62 #define DEBUG_VP3 0
63 #define DEBUG_INIT 0
64 #define DEBUG_DEQUANTIZERS 0
65 #define DEBUG_BLOCK_CODING 0
66 #define DEBUG_MODES 0
67 #define DEBUG_VECTORS 0
68 #define DEBUG_TOKEN 0
69 #define DEBUG_VLC 0
70 #define DEBUG_DC_PRED 0
71 #define DEBUG_IDCT 0
72
73 #if DEBUG_VP3
74 #define debug_vp3 printf
75 #else
76 static inline void debug_vp3(const char *format, ...) { }
77 #endif
78
79 #if DEBUG_INIT
80 #define debug_init printf
81 #else
82 static inline void debug_init(const char *format, ...) { }
83 #endif
84
85 #if DEBUG_DEQUANTIZERS
86 #define debug_dequantizers printf
87 #else
88 static inline void debug_dequantizers(const char *format, ...) { }
89 #endif
90
91 #if DEBUG_BLOCK_CODING
92 #define debug_block_coding printf
93 #else
94 static inline void debug_block_coding(const char *format, ...) { }
95 #endif
96
97 #if DEBUG_MODES
98 #define debug_modes printf
99 #else
100 static inline void debug_modes(const char *format, ...) { }
101 #endif
102
103 #if DEBUG_VECTORS
104 #define debug_vectors printf
105 #else
106 static inline void debug_vectors(const char *format, ...) { }
107 #endif
108
109 #if DEBUG_TOKEN
110 #define debug_token printf
111 #else
112 static inline void debug_token(const char *format, ...) { }
113 #endif
114
115 #if DEBUG_VLC
116 #define debug_vlc printf
117 #else
118 static inline void debug_vlc(const char *format, ...) { }
119 #endif
120
121 #if DEBUG_DC_PRED
122 #define debug_dc_pred printf
123 #else
124 static inline void debug_dc_pred(const char *format, ...) { }
125 #endif
126
127 #if DEBUG_IDCT
128 #define debug_idct printf
129 #else
130 static inline void debug_idct(const char *format, ...) { }
131 #endif
132
133 typedef struct Vp3Fragment {
134 DCTELEM coeffs[64];
135 int coding_method;
136 int coeff_count;
137 int last_coeff;
138 int motion_x;
139 int motion_y;
140 /* address of first pixel taking into account which plane the fragment
141 * lives on as well as the plane stride */
142 int first_pixel;
143 /* this is the macroblock that the fragment belongs to */
144 int macroblock;
145 } Vp3Fragment;
146
147 #define SB_NOT_CODED 0
148 #define SB_PARTIALLY_CODED 1
149 #define SB_FULLY_CODED 2
150
151 #define MODE_INTER_NO_MV 0
152 #define MODE_INTRA 1
153 #define MODE_INTER_PLUS_MV 2
154 #define MODE_INTER_LAST_MV 3
155 #define MODE_INTER_PRIOR_LAST 4
156 #define MODE_USING_GOLDEN 5
157 #define MODE_GOLDEN_MV 6
158 #define MODE_INTER_FOURMV 7
159 #define CODING_MODE_COUNT 8
160
161 /* special internal mode */
162 #define MODE_COPY 8
163
164 /* There are 6 preset schemes, plus a free-form scheme */
165 static int ModeAlphabet[7][CODING_MODE_COUNT] =
166 {
167 /* this is the custom scheme */
168 { 0, 0, 0, 0, 0, 0, 0, 0 },
169
170 /* scheme 1: Last motion vector dominates */
171 { MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
172 MODE_INTER_PLUS_MV, MODE_INTER_NO_MV,
173 MODE_INTRA, MODE_USING_GOLDEN,
174 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
175
176 /* scheme 2 */
177 { MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
178 MODE_INTER_NO_MV, MODE_INTER_PLUS_MV,
179 MODE_INTRA, MODE_USING_GOLDEN,
180 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
181
182 /* scheme 3 */
183 { MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
184 MODE_INTER_PRIOR_LAST, MODE_INTER_NO_MV,
185 MODE_INTRA, MODE_USING_GOLDEN,
186 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
187
188 /* scheme 4 */
189 { MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
190 MODE_INTER_NO_MV, MODE_INTER_PRIOR_LAST,
191 MODE_INTRA, MODE_USING_GOLDEN,
192 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
193
194 /* scheme 5: No motion vector dominates */
195 { MODE_INTER_NO_MV, MODE_INTER_LAST_MV,
196 MODE_INTER_PRIOR_LAST, MODE_INTER_PLUS_MV,
197 MODE_INTRA, MODE_USING_GOLDEN,
198 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
199
200 /* scheme 6 */
201 { MODE_INTER_NO_MV, MODE_USING_GOLDEN,
202 MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
203 MODE_INTER_PLUS_MV, MODE_INTRA,
204 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
205
206 };
207
208 #define MIN_DEQUANT_VAL 2
209
210 typedef struct Vp3DecodeContext {
211 AVCodecContext *avctx;
212 int width, height;
213 AVFrame golden_frame;
214 AVFrame last_frame;
215 AVFrame current_frame;
216 int keyframe;
217 DSPContext dsp;
218
219 int quality_index;
220 int last_quality_index;
221
222 int superblock_count;
223 int superblock_width;
224 int superblock_height;
225 int u_superblock_start;
226 int v_superblock_start;
227 unsigned char *superblock_coding;
228
229 int macroblock_count;
230 int macroblock_width;
231 int macroblock_height;
232
233 int fragment_count;
234 int fragment_width;
235 int fragment_height;
236
237 Vp3Fragment *all_fragments;
238 int u_fragment_start;
239 int v_fragment_start;
240
241 /* this is a list of indices into the all_fragments array indicating
242 * which of the fragments are coded */
243 int *coded_fragment_list;
244 int coded_fragment_list_index;
245 int pixel_addresses_inited;
246
247 VLC dc_vlc[16];
248 VLC ac_vlc_1[16];
249 VLC ac_vlc_2[16];
250 VLC ac_vlc_3[16];
251 VLC ac_vlc_4[16];
252
253 int16_t intra_y_dequant[64];
254 int16_t intra_c_dequant[64];
255 int16_t inter_dequant[64];
256
257 /* This table contains superblock_count * 16 entries. Each set of 16
258 * numbers corresponds to the fragment indices 0..15 of the superblock.
259 * An entry will be -1 to indicate that no entry corresponds to that
260 * index. */
261 int *superblock_fragments;
262
263 /* This table contains superblock_count * 4 entries. Each set of 4
264 * numbers corresponds to the macroblock indices 0..3 of the superblock.
265 * An entry will be -1 to indicate that no entry corresponds to that
266 * index. */
267 int *superblock_macroblocks;
268
269 /* This table contains macroblock_count * 6 entries. Each set of 6
270 * numbers corresponds to the fragment indices 0..5 which comprise
271 * the macroblock (4 Y fragments and 2 C fragments). */
272 int *macroblock_fragments;
273 /* This is an array of flags indicating whether a particular
274 * macroblock is coded. */
275 unsigned char *macroblock_coded;
276
277 } Vp3DecodeContext;
278
279 /************************************************************************
280 * VP3 specific functions
281 ************************************************************************/
282
283 /*
284 * This function sets up all of the various blocks mappings:
285 * superblocks <-> fragments, macroblocks <-> fragments,
286 * superblocks <-> macroblocks
287 */
288 static void init_block_mapping(Vp3DecodeContext *s)
289 {
290 int i, j;
291 signed int hilbert_walk_y[16];
292 signed int hilbert_walk_c[16];
293 signed int hilbert_walk_mb[4];
294
295 int current_fragment = 0;
296 int current_width = 0;
297 int current_height = 0;
298 int right_edge = 0;
299 int bottom_edge = 0;
300 int superblock_row_inc = 0;
301 int *hilbert = NULL;
302 int mapping_index = 0;
303
304 int current_macroblock;
305 int c_fragment;
306
307 signed char travel_width[16] = {
308 1, 1, 0, -1,
309 0, 0, 1, 0,
310 1, 0, 1, 0,
311 0, -1, 0, 1
312 };
313
314 signed char travel_height[16] = {
315 0, 0, 1, 0,
316 1, 1, 0, -1,
317 0, 1, 0, -1,
318 -1, 0, -1, 0
319 };
320
321 signed char travel_width_mb[4] = {
322 1, 0, 1, 0
323 };
324
325 signed char travel_height_mb[4] = {
326 0, 1, 0, -1
327 };
328
329 debug_vp3(" vp3: initialize block mapping tables\n");
330
331 /* figure out hilbert pattern per these frame dimensions */
332 hilbert_walk_y[0] = 1;
333 hilbert_walk_y[1] = 1;
334 hilbert_walk_y[2] = s->fragment_width;
335 hilbert_walk_y[3] = -1;
336 hilbert_walk_y[4] = s->fragment_width;
337 hilbert_walk_y[5] = s->fragment_width;
338 hilbert_walk_y[6] = 1;
339 hilbert_walk_y[7] = -s->fragment_width;
340 hilbert_walk_y[8] = 1;
341 hilbert_walk_y[9] = s->fragment_width;
342 hilbert_walk_y[10] = 1;
343 hilbert_walk_y[11] = -s->fragment_width;
344 hilbert_walk_y[12] = -s->fragment_width;
345 hilbert_walk_y[13] = -1;
346 hilbert_walk_y[14] = -s->fragment_width;
347 hilbert_walk_y[15] = 1;
348
349 hilbert_walk_c[0] = 1;
350 hilbert_walk_c[1] = 1;
351 hilbert_walk_c[2] = s->fragment_width / 2;
352 hilbert_walk_c[3] = -1;
353 hilbert_walk_c[4] = s->fragment_width / 2;
354 hilbert_walk_c[5] = s->fragment_width / 2;
355 hilbert_walk_c[6] = 1;
356 hilbert_walk_c[7] = -s->fragment_width / 2;
357 hilbert_walk_c[8] = 1;
358 hilbert_walk_c[9] = s->fragment_width / 2;
359 hilbert_walk_c[10] = 1;
360 hilbert_walk_c[11] = -s->fragment_width / 2;
361 hilbert_walk_c[12] = -s->fragment_width / 2;
362 hilbert_walk_c[13] = -1;
363 hilbert_walk_c[14] = -s->fragment_width / 2;
364 hilbert_walk_c[15] = 1;
365
366 hilbert_walk_mb[0] = 1;
367 hilbert_walk_mb[1] = s->macroblock_width;
368 hilbert_walk_mb[2] = 1;
369 hilbert_walk_mb[3] = -s->macroblock_width;
370
371 /* iterate through each superblock (all planes) and map the fragments */
372 for (i = 0; i < s->superblock_count; i++) {
373 debug_init(" superblock %d (u starts @ %d, v starts @ %d)\n",
374 i, s->u_superblock_start, s->v_superblock_start);
375
376 /* time to re-assign the limits? */
377 if (i == 0) {
378
379 /* start of Y superblocks */
380 right_edge = s->fragment_width;
381 bottom_edge = s->fragment_height;
382 current_width = 0;
383 current_height = 0;
384 superblock_row_inc = 3 * s->fragment_width;
385 hilbert = hilbert_walk_y;
386
387 /* the first operation for this variable is to advance by 1 */
388 current_fragment = -1;
389
390 } else if (i == s->u_superblock_start) {
391
392 /* start of U superblocks */
393 right_edge = s->fragment_width / 2;
394 bottom_edge = s->fragment_height / 2;
395 current_width = 0;
396 current_height = 0;
397 superblock_row_inc = 3 * (s->fragment_width / 2);
398 hilbert = hilbert_walk_c;
399
400 /* the first operation for this variable is to advance by 1 */
401 current_fragment = s->u_fragment_start - 1;
402
403 } else if (i == s->v_superblock_start) {
404
405 /* start of V superblocks */
406 right_edge = s->fragment_width / 2;
407 bottom_edge = s->fragment_height / 2;
408 current_width = 0;
409 current_height = 0;
410 superblock_row_inc = 3 * (s->fragment_width / 2);
411 hilbert = hilbert_walk_c;
412
413 /* the first operation for this variable is to advance by 1 */
414 current_fragment = s->v_fragment_start - 1;
415
416 }
417
418 if (current_width >= right_edge) {
419 /* reset width and move to next superblock row */
420 current_width = 0;
421 current_height += 4;
422
423 /* fragment is now at the start of a new superblock row */
424 current_fragment += superblock_row_inc;
425 }
426
427 /* iterate through all 16 fragments in a superblock */
428 for (j = 0; j < 16; j++) {
429 current_fragment += hilbert[j];
430 current_height += travel_height[j];
431
432 /* check if the fragment is in bounds */
433 if ((current_width <= right_edge) &&
434 (current_height < bottom_edge)) {
435 s->superblock_fragments[mapping_index] = current_fragment;
436 debug_init(" mapping fragment %d to superblock %d, position %d\n",
437 s->superblock_fragments[mapping_index], i, j);
438 } else {
439 s->superblock_fragments[mapping_index] = -1;
440 debug_init(" superblock %d, position %d has no fragment\n",
441 i, j);
442 }
443
444 current_width += travel_width[j];
445 mapping_index++;
446 }
447 }
448
449 /* initialize the superblock <-> macroblock mapping; iterate through
450 * all of the Y plane superblocks to build this mapping */
451 right_edge = s->macroblock_width;
452 bottom_edge = s->macroblock_height;
453 current_width = 0;
454 current_height = 0;
455 superblock_row_inc = s->macroblock_width;
456 hilbert = hilbert_walk_mb;
457 mapping_index = 0;
458 current_macroblock = -1;
459 for (i = 0; i < s->u_superblock_start; i++) {
460
461 if (current_width >= right_edge) {
462 /* reset width and move to next superblock row */
463 current_width = 0;
464 current_height += 2;
465
466 /* macroblock is now at the start of a new superblock row */
467 current_macroblock += superblock_row_inc;
468 }
469
470 /* iterate through each potential macroblock in the superblock */
471 for (j = 0; j < 4; j++) {
472 current_macroblock += hilbert_walk_mb[j];
473 current_height += travel_height_mb[j];
474
475 /* check if the macroblock is in bounds */
476 if ((current_width <= right_edge) &&
477 (current_height < bottom_edge)) {
478 s->superblock_macroblocks[mapping_index] = current_macroblock;
479 debug_init(" mapping macroblock %d to superblock %d, position %d\n",
480 s->superblock_macroblocks[mapping_index], i, j);
481 } else {
482 s->superblock_macroblocks[mapping_index] = -1;
483 debug_init(" superblock %d, position %d has no macroblock\n",
484 i, j);
485 }
486
487 current_width += travel_width_mb[j];
488 mapping_index++;
489 }
490 }
491
492 /* initialize the macroblock <-> fragment mapping */
493 current_fragment = 0;
494 current_macroblock = 0;
495 mapping_index = 0;
496 for (i = 0; i < s->fragment_height; i += 2) {
497
498 for (j = 0; j < s->fragment_width; j += 2) {
499
500 debug_init(" macroblock %d contains fragments: ", current_macroblock);
501 s->all_fragments[current_fragment].macroblock = current_macroblock;
502 s->macroblock_fragments[mapping_index++] = current_fragment;
503 debug_init("%d ", current_fragment);
504
505 if (j + 1 < s->fragment_width) {
506 s->all_fragments[current_fragment + 1].macroblock = current_macroblock;
507 s->macroblock_fragments[mapping_index++] = current_fragment + 1;
508 debug_init("%d ", current_fragment + 1);
509 } else
510 s->macroblock_fragments[mapping_index++] = -1;
511
512 if (i + 1 < s->fragment_height) {
513 s->all_fragments[current_fragment + s->fragment_width].macroblock =
514 current_macroblock;
515 s->macroblock_fragments[mapping_index++] =
516 current_fragment + s->fragment_width;
517 debug_init("%d ", current_fragment + s->fragment_width);
518 } else
519 s->macroblock_fragments[mapping_index++] = -1;
520
521 if ((j + 1 < s->fragment_width) && (i + 1 < s->fragment_height)) {
522 s->all_fragments[current_fragment + s->fragment_width + 1].macroblock =
523 current_macroblock;
524 s->macroblock_fragments[mapping_index++] =
525 current_fragment + s->fragment_width + 1;
526 debug_init("%d ", current_fragment + s->fragment_width + 1);
527 } else
528 s->macroblock_fragments[mapping_index++] = -1;
529
530 /* C planes */
531 c_fragment = s->u_fragment_start +
532 (i * s->fragment_width / 4) + (j / 2);
533 s->all_fragments[c_fragment].macroblock = s->macroblock_count;
534 s->macroblock_fragments[mapping_index++] = c_fragment;
535 debug_init("%d ", c_fragment);
536
537 c_fragment = s->v_fragment_start +
538 (i * s->fragment_width / 4) + (j / 2);
539 s->all_fragments[c_fragment].macroblock = s->macroblock_count;
540 s->macroblock_fragments[mapping_index++] = c_fragment;
541 debug_init("%d ", c_fragment);
542
543 debug_init("\n");
544
545 if (j + 2 <= s->fragment_width)
546 current_fragment += 2;
547 else
548 current_fragment++;
549 current_macroblock++;
550 }
551
552 current_fragment += s->fragment_width;
553 }
554 }
555
556 /*
557 * This function unpacks a single token (which should be in the range 0..31)
558 * and returns a zero run (number of zero coefficients in current DCT matrix
559 * before next non-zero coefficient), the next DCT coefficient, and the
560 * number of consecutive, non-EOB'd DCT blocks to EOB.
561 */
562 static void unpack_token(GetBitContext *gb, int token, int *zero_run,
563 DCTELEM *coeff, int *eob_run)
564 {
565 int sign;
566
567 *zero_run = 0;
568 *eob_run = 0;
569 *coeff = 0;
570
571 debug_token(" vp3 token %d: ", token);
572 switch (token) {
573
574 case 0:
575 debug_token("DCT_EOB_TOKEN, EOB next block\n");
576 *eob_run = 1;
577 break;
578
579 case 1:
580 debug_token("DCT_EOB_PAIR_TOKEN, EOB next 2 blocks\n");
581 *eob_run = 2;
582 break;
583
584 case 2:
585 debug_token("DCT_EOB_TRIPLE_TOKEN, EOB next 3 blocks\n");
586 *eob_run = 3;
587 break;
588
589 case 3:
590 debug_token("DCT_REPEAT_RUN_TOKEN, ");
591 *eob_run = get_bits(gb, 2) + 4;
592 debug_token("EOB the next %d blocks\n", *eob_run);
593 break;
594
595 case 4:
596 debug_token("DCT_REPEAT_RUN2_TOKEN, ");
597 *eob_run = get_bits(gb, 3) + 8;
598 debug_token("EOB the next %d blocks\n", *eob_run);
599 break;
600
601 case 5:
602 debug_token("DCT_REPEAT_RUN3_TOKEN, ");
603 *eob_run = get_bits(gb, 4) + 16;
604 debug_token("EOB the next %d blocks\n", *eob_run);
605 break;
606
607 case 6:
608 debug_token("DCT_REPEAT_RUN4_TOKEN, ");
609 *eob_run = get_bits(gb, 12);
610 debug_token("EOB the next %d blocks\n", *eob_run);
611 break;
612
613 case 7:
614 debug_token("DCT_SHORT_ZRL_TOKEN, ");
615 /* note that this token actually indicates that (3 extra bits) + 1 0s
616 * should be output; this case specifies a run of (3 EBs) 0s and a
617 * coefficient of 0. */
618 *zero_run = get_bits(gb, 3);
619 *coeff = 0;
620 debug_token("skip the next %d positions in output matrix\n", *zero_run + 1);
621 break;
622
623 case 8:
624 debug_token("DCT_ZRL_TOKEN, ");
625 /* note that this token actually indicates that (6 extra bits) + 1 0s
626 * should be output; this case specifies a run of (6 EBs) 0s and a
627 * coefficient of 0. */
628 *zero_run = get_bits(gb, 6);
629 *coeff = 0;
630 debug_token("skip the next %d positions in output matrix\n", *zero_run + 1);
631 break;
632
633 case 9:
634 debug_token("ONE_TOKEN, output 1\n");
635 *coeff = 1;
636 break;
637
638 case 10:
639 debug_token("MINUS_ONE_TOKEN, output -1\n");
640 *coeff = -1;
641 break;
642
643 case 11:
644 debug_token("TWO_TOKEN, output 2\n");
645 *coeff = 2;
646 break;
647
648 case 12:
649 debug_token("MINUS_TWO_TOKEN, output -2\n");
650 *coeff = -2;
651 break;
652
653 case 13:
654 case 14:
655 case 15:
656 case 16:
657 debug_token("LOW_VAL_TOKENS, ");
658 if (get_bits(gb, 1))
659 *coeff = -(3 + (token - 13));
660 else
661 *coeff = 3 + (token - 13);
662 debug_token("output %d\n", *coeff);
663 break;
664
665 case 17:
666 debug_token("DCT_VAL_CATEGORY3, ");
667 sign = get_bits(gb, 1);
668 *coeff = 7 + get_bits(gb, 1);
669 if (sign)
670 *coeff = -(*coeff);
671 debug_token("output %d\n", *coeff);
672 break;
673
674 case 18:
675 debug_token("DCT_VAL_CATEGORY4, ");
676 sign = get_bits(gb, 1);
677 *coeff = 9 + get_bits(gb, 2);
678 if (sign)
679 *coeff = -(*coeff);
680 debug_token("output %d\n", *coeff);
681 break;
682
683 case 19:
684 debug_token("DCT_VAL_CATEGORY5, ");
685 sign = get_bits(gb, 1);
686 *coeff = 13 + get_bits(gb, 3);
687 if (sign)
688 *coeff = -(*coeff);
689 debug_token("output %d\n", *coeff);
690 break;
691
692 case 20:
693 debug_token("DCT_VAL_CATEGORY6, ");
694 sign = get_bits(gb, 1);
695 *coeff = 21 + get_bits(gb, 4);
696 if (sign)
697 *coeff = -(*coeff);
698 debug_token("output %d\n", *coeff);
699 break;
700
701 case 21:
702 debug_token("DCT_VAL_CATEGORY7, ");
703 sign = get_bits(gb, 1);
704 *coeff = 37 + get_bits(gb, 5);
705 if (sign)
706 *coeff = -(*coeff);
707 debug_token("output %d\n", *coeff);
708 break;
709
710 case 22:
711 debug_token("DCT_VAL_CATEGORY8, ");
712 sign = get_bits(gb, 1);
713 *coeff = 69 + get_bits(gb, 9);
714 if (sign)
715 *coeff = -(*coeff);
716 debug_token("output %d\n", *coeff);
717 break;
718
719 case 23:
720 case 24:
721 case 25:
722 case 26:
723 case 27:
724 debug_token("DCT_RUN_CATEGORY1, ");
725 *zero_run = token - 22;
726 if (get_bits(gb, 1))
727 *coeff = -1;
728 else
729 *coeff = 1;
730 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
731 break;
732
733 case 28:
734 debug_token("DCT_RUN_CATEGORY1B, ");
735 if (get_bits(gb, 1))
736 *coeff = -1;
737 else
738 *coeff = 1;
739 *zero_run = 6 + get_bits(gb, 2);
740 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
741 break;
742
743 case 29:
744 debug_token("DCT_RUN_CATEGORY1C, ");
745 if (get_bits(gb, 1))
746 *coeff = -1;
747 else
748 *coeff = 1;
749 *zero_run = 10 + get_bits(gb, 3);
750 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
751 break;
752
753 case 30:
754 debug_token("DCT_RUN_CATEGORY2, ");
755 sign = get_bits(gb, 1);
756 *coeff = 2 + get_bits(gb, 1);
757 if (sign)
758 *coeff = -(*coeff);
759 *zero_run = 1;
760 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
761 break;
762
763 case 31:
764 debug_token("DCT_RUN_CATEGORY2, ");
765 sign = get_bits(gb, 1);
766 *coeff = 2 + get_bits(gb, 1);
767 if (sign)
768 *coeff = -(*coeff);
769 *zero_run = 2 + get_bits(gb, 1);
770 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
771 break;
772
773 default:
774 printf (" vp3: help! Got a bad token: %d > 31\n", token);
775 break;
776
777 }
778 }
779
780 /*
781 * This function wipes out all of the fragment data.
782 */
783 static void init_frame(Vp3DecodeContext *s, GetBitContext *gb)
784 {
785 int i;
786
787 /* zero out all of the fragment information */
788 s->coded_fragment_list_index = 0;
789 for (i = 0; i < s->fragment_count; i++) {
790 memset(s->all_fragments[i].coeffs, 0, 64 * sizeof(DCTELEM));
791 s->all_fragments[i].coeff_count = 0;
792 s->all_fragments[i].last_coeff = 0;
793 }
794 }
795
796 /*
797 * This function sets of the dequantization tables used for a particular
798 * frame.
799 */
800 static void init_dequantizer(Vp3DecodeContext *s)
801 {
802
803 int quality_scale = vp31_quality_threshold[s->quality_index];
804 int dc_scale_factor = vp31_dc_scale_factor[s->quality_index];
805 int i, j;
806
807 debug_vp3(" vp3: initializing dequantization tables\n");
808
809 /*
810 * Scale dequantizers:
811 *
812 * quantizer * sf
813 * --------------
814 * 100
815 *
816 * where sf = dc_scale_factor for DC quantizer
817 * or quality_scale for AC quantizer
818 *
819 * Then, saturate the result to a lower limit of MIN_DEQUANT_VAL.
820 */
821 #define SCALER 1
822
823 /* scale DC quantizers */
824 s->intra_y_dequant[0] = vp31_intra_y_dequant[0] * dc_scale_factor / 100;
825 if (s->intra_y_dequant[0] < MIN_DEQUANT_VAL * 2)
826 s->intra_y_dequant[0] = MIN_DEQUANT_VAL * 2;
827 s->intra_y_dequant[0] *= SCALER;
828
829 s->intra_c_dequant[0] = vp31_intra_c_dequant[0] * dc_scale_factor / 100;
830 if (s->intra_c_dequant[0] < MIN_DEQUANT_VAL * 2)
831 s->intra_c_dequant[0] = MIN_DEQUANT_VAL * 2;
832 s->intra_c_dequant[0] *= SCALER;
833
834 s->inter_dequant[0] = vp31_inter_dequant[0] * dc_scale_factor / 100;
835 if (s->inter_dequant[0] < MIN_DEQUANT_VAL * 4)
836 s->inter_dequant[0] = MIN_DEQUANT_VAL * 4;
837 s->inter_dequant[0] *= SCALER;
838
839 /* scale AC quantizers, zigzag at the same time in preparation for
840 * the dequantization phase */
841 for (i = 1; i < 64; i++) {
842
843 j = quant_index[i];
844
845 s->intra_y_dequant[j] = vp31_intra_y_dequant[i] * quality_scale / 100;
846 if (s->intra_y_dequant[j] < MIN_DEQUANT_VAL)
847 s->intra_y_dequant[j] = MIN_DEQUANT_VAL;
848 s->intra_y_dequant[j] *= SCALER;
849
850 s->intra_c_dequant[j] = vp31_intra_c_dequant[i] * quality_scale / 100;
851 if (s->intra_c_dequant[j] < MIN_DEQUANT_VAL)
852 s->intra_c_dequant[j] = MIN_DEQUANT_VAL;
853 s->intra_c_dequant[j] *= SCALER;
854
855 s->inter_dequant[j] = vp31_inter_dequant[i] * quality_scale / 100;
856 if (s->inter_dequant[j] < MIN_DEQUANT_VAL * 2)
857 s->inter_dequant[j] = MIN_DEQUANT_VAL * 2;
858 s->inter_dequant[j] *= SCALER;
859 }
860
861 /* print debug information as requested */
862 debug_dequantizers("intra Y dequantizers:\n");
863 for (i = 0; i < 8; i++) {
864 for (j = i * 8; j < i * 8 + 8; j++) {
865 debug_dequantizers(" %4d,", s->intra_y_dequant[j]);
866 }
867 debug_dequantizers("\n");
868 }
869 debug_dequantizers("\n");
870
871 debug_dequantizers("intra C dequantizers:\n");
872 for (i = 0; i < 8; i++) {
873 for (j = i * 8; j < i * 8 + 8; j++) {
874 debug_dequantizers(" %4d,", s->intra_c_dequant[j]);
875 }
876 debug_dequantizers("\n");
877 }
878 debug_dequantizers("\n");
879
880 debug_dequantizers("interframe dequantizers:\n");
881 for (i = 0; i < 8; i++) {
882 for (j = i * 8; j < i * 8 + 8; j++) {
883 debug_dequantizers(" %4d,", s->inter_dequant[j]);
884 }
885 debug_dequantizers("\n");
886 }
887 debug_dequantizers("\n");
888 }
889
890 /*
891 * This function is used to fetch runs of 1s or 0s from the bitstream for
892 * use in determining which superblocks are fully and partially coded.
893 *
894 * Codeword RunLength
895 * 0 1
896 * 10x 2-3
897 * 110x 4-5
898 * 1110xx 6-9
899 * 11110xxx 10-17
900 * 111110xxxx 18-33
901 * 111111xxxxxxxxxxxx 34-4129
902 */
903 static int get_superblock_run_length(GetBitContext *gb)
904 {
905
906 if (get_bits(gb, 1) == 0)
907 return 1;
908
909 else if (get_bits(gb, 1) == 0)
910 return (2 + get_bits(gb, 1));
911
912 else if (get_bits(gb, 1) == 0)
913 return (4 + get_bits(gb, 1));
914
915 else if (get_bits(gb, 1) == 0)
916 return (6 + get_bits(gb, 2));
917
918 else if (get_bits(gb, 1) == 0)
919 return (10 + get_bits(gb, 3));
920
921 else if (get_bits(gb, 1) == 0)
922 return (18 + get_bits(gb, 4));
923
924 else
925 return (34 + get_bits(gb, 12));
926
927 }
928
929 /*
930 * This function is used to fetch runs of 1s or 0s from the bitstream for
931 * use in determining which particular fragments are coded.
932 *
933 * Codeword RunLength
934 * 0x 1-2
935 * 10x 3-4
936 * 110x 5-6
937 * 1110xx 7-10
938 * 11110xx 11-14
939 * 11111xxxx 15-30
940 */
941 static int get_fragment_run_length(GetBitContext *gb)
942 {
943
944 if (get_bits(gb, 1) == 0)
945 return (1 + get_bits(gb, 1));
946
947 else if (get_bits(gb, 1) == 0)
948 return (3 + get_bits(gb, 1));
949
950 else if (get_bits(gb, 1) == 0)
951 return (5 + get_bits(gb, 1));
952
953 else if (get_bits(gb, 1) == 0)
954 return (7 + get_bits(gb, 2));
955
956 else if (get_bits(gb, 1) == 0)
957 return (11 + get_bits(gb, 2));
958
959 else
960 return (15 + get_bits(gb, 4));
961
962 }
963
964 /*
965 * This function decodes a VLC from the bitstream and returns a number
966 * that ranges from 0..7. The number indicates which of the 8 coding
967 * modes to use.
968 *
969 * VLC Number
970 * 0 0
971 * 10 1
972 * 110 2
973 * 1110 3
974 * 11110 4
975 * 111110 5
976 * 1111110 6
977 * 1111111 7
978 *
979 */
980 static int get_mode_code(GetBitContext *gb)
981 {
982
983 if (get_bits(gb, 1) == 0)
984 return 0;
985
986 else if (get_bits(gb, 1) == 0)
987 return 1;
988
989 else if (get_bits(gb, 1) == 0)
990 return 2;
991
992 else if (get_bits(gb, 1) == 0)
993 return 3;
994
995 else if (get_bits(gb, 1) == 0)
996 return 4;
997
998 else if (get_bits(gb, 1) == 0)
999 return 5;
1000
1001 else if (get_bits(gb, 1) == 0)
1002 return 6;
1003
1004 else
1005 return 7;
1006
1007 }
1008
1009 /*
1010 * This function extracts a motion vector from the bitstream using a VLC
1011 * scheme. 3 bits are fetched from the bitstream and 1 of 8 actions is
1012 * taken depending on the value on those 3 bits:
1013 *
1014 * 0: return 0
1015 * 1: return 1
1016 * 2: return -1
1017 * 3: if (next bit is 1) return -2, else return 2
1018 * 4: if (next bit is 1) return -3, else return 3
1019 * 5: return 4 + (next 2 bits), next bit is sign
1020 * 6: return 8 + (next 3 bits), next bit is sign
1021 * 7: return 16 + (next 4 bits), next bit is sign
1022 */
1023 static int get_motion_vector_vlc(GetBitContext *gb)
1024 {
1025 int bits;
1026
1027 bits = get_bits(gb, 3);
1028
1029 switch(bits) {
1030
1031 case 0:
1032 bits = 0;
1033 break;
1034
1035 case 1:
1036 bits = 1;
1037 break;
1038
1039 case 2:
1040 bits = -1;
1041 break;
1042
1043 case 3:
1044 if (get_bits(gb, 1) == 0)
1045 bits = 2;
1046 else
1047 bits = -2;
1048 break;
1049
1050 case 4:
1051 if (get_bits(gb, 1) == 0)
1052 bits = 3;
1053 else
1054 bits = -3;
1055 break;
1056
1057 case 5:
1058 bits = 4 + get_bits(gb, 2);
1059 if (get_bits(gb, 1) == 1)
1060 bits = -bits;
1061 break;
1062
1063 case 6:
1064 bits = 8 + get_bits(gb, 3);
1065 if (get_bits(gb, 1) == 1)
1066 bits = -bits;
1067 break;
1068
1069 case 7:
1070 bits = 16 + get_bits(gb, 4);
1071 if (get_bits(gb, 1) == 1)
1072 bits = -bits;
1073 break;
1074
1075 }
1076
1077 return bits;
1078 }
1079
1080 /*
1081 * This function fetches a 5-bit number from the stream followed by
1082 * a sign and calls it a motion vector.
1083 */
1084 static int get_motion_vector_fixed(GetBitContext *gb)
1085 {
1086
1087 int bits;
1088
1089 bits = get_bits(gb, 5);
1090
1091 if (get_bits(gb, 1) == 1)
1092 bits = -bits;
1093
1094 return bits;
1095 }
1096
1097 /*
1098 * This function unpacks all of the superblock/macroblock/fragment coding
1099 * information from the bitstream.
1100 */
1101 static void unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
1102 {
1103 int bit = 0;
1104 int current_superblock = 0;
1105 int current_run = 0;
1106 int decode_fully_flags = 0;
1107 int decode_partial_blocks = 0;
1108
1109 int i, j;
1110 int current_fragment;
1111
1112 debug_vp3(" vp3: unpacking superblock coding\n");
1113
1114 if (s->keyframe) {
1115
1116 debug_vp3(" keyframe-- all superblocks are fully coded\n");
1117 memset(s->superblock_coding, SB_FULLY_CODED, s->superblock_count);
1118
1119 } else {
1120
1121 /* unpack the list of partially-coded superblocks */
1122 bit = get_bits(gb, 1);
1123 /* toggle the bit because as soon as the first run length is
1124 * fetched the bit will be toggled again */
1125 bit ^= 1;
1126 while (current_superblock < s->superblock_count) {
1127 if (current_run == 0) {
1128 bit ^= 1;
1129 current_run = get_superblock_run_length(gb);
1130 debug_block_coding(" setting superblocks %d..%d to %s\n",
1131 current_superblock,
1132 current_superblock + current_run - 1,
1133 (bit) ? "partially coded" : "not coded");
1134
1135 /* if any of the superblocks are not partially coded, flag
1136 * a boolean to decode the list of fully-coded superblocks */
1137 if (bit == 0)
1138 decode_fully_flags = 1;
1139 } else {
1140
1141 /* make a note of the fact that there are partially coded
1142 * superblocks */
1143 decode_partial_blocks = 1;
1144
1145 }
1146 s->superblock_coding[current_superblock++] =
1147 (bit) ? SB_PARTIALLY_CODED : SB_NOT_CODED;
1148 current_run--;
1149 }
1150
1151 /* unpack the list of fully coded superblocks if any of the blocks were
1152 * not marked as partially coded in the previous step */
1153 if (decode_fully_flags) {
1154
1155 current_superblock = 0;
1156 current_run = 0;
1157 bit = get_bits(gb, 1);
1158 /* toggle the bit because as soon as the first run length is
1159 * fetched the bit will be toggled again */
1160 bit ^= 1;
1161 while (current_superblock < s->superblock_count) {
1162
1163 /* skip any superblocks already marked as partially coded */
1164 if (s->superblock_coding[current_superblock] == SB_NOT_CODED) {
1165
1166 if (current_run == 0) {
1167 bit ^= 1;
1168 current_run = get_superblock_run_length(gb);
1169 }
1170
1171 debug_block_coding(" setting superblock %d to %s\n",
1172 current_superblock,
1173 (bit) ? "fully coded" : "not coded");
1174 s->superblock_coding[current_superblock] =
1175 (bit) ? SB_FULLY_CODED : SB_NOT_CODED;
1176 current_run--;
1177 }
1178 current_superblock++;
1179 }
1180 }
1181
1182 /* if there were partial blocks, initialize bitstream for
1183 * unpacking fragment codings */
1184 if (decode_partial_blocks) {
1185
1186 current_run = 0;
1187 bit = get_bits(gb, 1);
1188 /* toggle the bit because as soon as the first run length is
1189 * fetched the bit will be toggled again */
1190 bit ^= 1;
1191 }
1192 }
1193
1194 /* figure out which fragments are coded; iterate through each
1195 * superblock (all planes) */
1196 s->coded_fragment_list_index = 0;
1197 memset(s->macroblock_coded, 0, s->macroblock_count);
1198 for (i = 0; i < s->superblock_count; i++) {
1199
1200 /* iterate through all 16 fragments in a superblock */
1201 for (j = 0; j < 16; j++) {
1202
1203 /* if the fragment is in bounds, check its coding status */
1204 current_fragment = s->superblock_fragments[i * 16 + j];
1205 if (current_fragment != -1) {
1206 if (s->superblock_coding[i] == SB_NOT_CODED) {
1207
1208 /* copy all the fragments from the prior frame */
1209 s->all_fragments[current_fragment].coding_method =
1210 MODE_COPY;
1211
1212 } else if (s->superblock_coding[i] == SB_PARTIALLY_CODED) {
1213
1214 /* fragment may or may not be coded; this is the case
1215 * that cares about the fragment coding runs */
1216 if (current_run == 0) {
1217 bit ^= 1;
1218 current_run = get_fragment_run_length(gb);
1219 }
1220
1221 if (bit) {
1222 /* mode will be decoded in the next phase */
1223 s->all_fragments[current_fragment].coding_method =
1224 MODE_INTER_NO_MV;
1225 s->coded_fragment_list[s->coded_fragment_list_index++] =
1226 current_fragment;
1227 s->macroblock_coded[s->all_fragments[current_fragment].macroblock] = 1;
1228 debug_block_coding(" superblock %d is partially coded, fragment %d is coded\n",
1229 i, current_fragment);
1230 } else {
1231 /* not coded; copy this fragment from the prior frame */
1232 s->all_fragments[current_fragment].coding_method =
1233 MODE_COPY;
1234 debug_block_coding(" superblock %d is partially coded, fragment %d is not coded\n",
1235 i, current_fragment);
1236 }
1237
1238 current_run--;
1239
1240 } else {
1241
1242 /* fragments are fully coded in this superblock; actual
1243 * coding will be determined in next step */
1244 s->all_fragments[current_fragment].coding_method =
1245 MODE_INTER_NO_MV;
1246 s->coded_fragment_list[s->coded_fragment_list_index++] =
1247 current_fragment;
1248 s->macroblock_coded[s->all_fragments[current_fragment].macroblock] = 1;
1249 debug_block_coding(" superblock %d is fully coded, fragment %d is coded\n",
1250 i, current_fragment);
1251 }
1252 }
1253 }
1254 }
1255 }
1256
1257 /*
1258 * This function unpacks all the coding mode data for individual macroblocks
1259 * from the bitstream.
1260 */
1261 static void unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
1262 {
1263 int i, j, k;
1264 int scheme;
1265 int current_macroblock;
1266 int current_fragment;
1267 int coding_mode;
1268
1269 debug_vp3(" vp3: unpacking encoding modes\n");
1270
1271 if (s->keyframe) {
1272 debug_vp3(" keyframe-- all blocks are coded as INTRA\n");
1273
1274 for (i = 0; i < s->fragment_count; i++)
1275 s->all_fragments[i].coding_method = MODE_INTRA;
1276
1277 } else {
1278
1279 /* fetch the mode coding scheme for this frame */
1280 scheme = get_bits(gb, 3);
1281 debug_modes(" using mode alphabet %d\n", scheme);
1282
1283 /* is it a custom coding scheme? */
1284 if (scheme == 0) {
1285 debug_modes(" custom mode alphabet ahead:\n");
1286 for (i = 0; i < 8; i++)
1287 ModeAlphabet[0][i] = get_bits(gb, 3);
1288 }
1289
1290 for (i = 0; i < 8; i++)
1291 debug_modes(" mode[%d][%d] = %d\n", scheme, i,
1292 ModeAlphabet[scheme][i]);
1293
1294 /* iterate through all of the macroblocks that contain 1 or more
1295 * coded fragments */
1296 for (i = 0; i < s->u_superblock_start; i++) {
1297
1298 for (j = 0; j < 4; j++) {
1299 current_macroblock = s->superblock_macroblocks[i * 4 + j];
1300 if ((current_macroblock == -1) ||
1301 (!s->macroblock_coded[current_macroblock]))
1302 continue;
1303
1304 /* mode 7 means get 3 bits for each coding mode */
1305 if (scheme == 7)
1306 coding_mode = get_bits(gb, 3);
1307 else
1308 coding_mode = ModeAlphabet[scheme][get_mode_code(gb)];
1309
1310 for (k = 0; k < 6; k++) {
1311 current_fragment =
1312 s->macroblock_fragments[current_macroblock * 6 + k];
1313 if (s->all_fragments[current_fragment].coding_method !=
1314 MODE_COPY)
1315 s->all_fragments[current_fragment].coding_method =
1316 coding_mode;
1317 }
1318
1319 debug_modes(" coding method for macroblock starting @ fragment %d = %d\n",
1320 s->macroblock_fragments[current_macroblock * 6], coding_mode);
1321 }
1322 }
1323 }
1324
1325 }
1326
1327 /*
1328 * This function unpacks all the motion vectors for the individual
1329 * macroblocks from the bitstream.
1330 */
1331 static void unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
1332 {
1333 int i, j, k;
1334 int coding_mode;
1335 int motion_x[6];
1336 int motion_y[6];
1337 int last_motion_x = 0;
1338 int last_motion_y = 0;
1339 int prior_last_motion_x = 0;
1340 int prior_last_motion_y = 0;
1341 int current_macroblock;
1342 int current_fragment;
1343
1344 debug_vp3(" vp3: unpacking motion vectors\n");
1345
1346 if (s->keyframe) {
1347
1348 debug_vp3(" keyframe-- there are no motion vectors\n");
1349
1350 } else {
1351
1352 memset(motion_x, 0, 6 * sizeof(int));
1353 memset(motion_y, 0, 6 * sizeof(int));
1354
1355 /* coding mode 0 is the VLC scheme; 1 is the fixed code scheme */
1356 coding_mode = get_bits(gb, 1);
1357 debug_vectors(" using %s scheme for unpacking motion vectors\n",
1358 (coding_mode == 0) ? "VLC" : "fixed-length");
1359
1360 /* iterate through all of the macroblocks that contain 1 or more
1361 * coded fragments */
1362 for (i = 0; i < s->u_superblock_start; i++) {
1363
1364 for (j = 0; j < 4; j++) {
1365 current_macroblock = s->superblock_macroblocks[i * 4 + j];
1366 if ((current_macroblock == -1) ||
1367 (!s->macroblock_coded[current_macroblock]))
1368 continue;
1369
1370 current_fragment = s->macroblock_fragments[current_macroblock * 6];
1371 switch (s->all_fragments[current_fragment].coding_method) {
1372
1373 case MODE_INTER_PLUS_MV:
1374 case MODE_GOLDEN_MV:
1375 /* all 6 fragments use the same motion vector */
1376 if (coding_mode == 0) {
1377 motion_x[0] = get_motion_vector_vlc(gb);
1378 motion_y[0] = get_motion_vector_vlc(gb);
1379 } else {
1380 motion_x[0] = get_motion_vector_fixed(gb);
1381 motion_y[0] = get_motion_vector_fixed(gb);
1382 }
1383 for (k = 1; k < 6; k++) {
1384 motion_x[k] = motion_x[0];
1385 motion_y[k] = motion_y[0];
1386 }
1387
1388 /* vector maintenance, only on MODE_INTER_PLUS_MV */
1389 if (s->all_fragments[current_fragment].coding_method ==
1390 MODE_INTER_PLUS_MV) {
1391 prior_last_motion_x = last_motion_x;
1392 prior_last_motion_y = last_motion_y;
1393 last_motion_x = motion_x[0];
1394 last_motion_y = motion_y[0];
1395 }
1396 break;
1397
1398 case MODE_INTER_FOURMV:
1399 /* fetch 4 vectors from the bitstream, one for each
1400 * Y fragment, then average for the C fragment vectors */
1401 motion_x[4] = motion_y[4] = 0;
1402 for (k = 0; k < 4; k++) {
1403 if (coding_mode == 0) {
1404 motion_x[k] = get_motion_vector_vlc(gb);
1405 motion_y[k] = get_motion_vector_vlc(gb);
1406 } else {
1407 motion_x[k] = get_motion_vector_fixed(gb);
1408 motion_y[k] = get_motion_vector_fixed(gb);
1409 }
1410 motion_x[4] += motion_x[k];
1411 motion_y[4] += motion_y[k];
1412 }
1413
1414 if (motion_x[4] >= 0)
1415 motion_x[4] = (motion_x[4] + 2) / 4;
1416 else
1417 motion_x[4] = (motion_x[4] - 2) / 4;
1418 motion_x[5] = motion_x[4];
1419
1420 if (motion_y[4] >= 0)
1421 motion_y[4] = (motion_y[4] + 2) / 4;
1422 else
1423 motion_y[4] = (motion_y[4] - 2) / 4;
1424 motion_y[5] = motion_y[4];
1425
1426 /* vector maintenance; vector[3] is treated as the
1427 * last vector in this case */
1428 prior_last_motion_x = last_motion_x;
1429 prior_last_motion_y = last_motion_y;
1430 last_motion_x = motion_x[3];
1431 last_motion_y = motion_y[3];
1432 break;
1433
1434 case MODE_INTER_LAST_MV:
1435 /* all 6 fragments use the last motion vector */
1436 motion_x[0] = last_motion_x;
1437 motion_y[0] = last_motion_y;
1438 for (k = 1; k < 6; k++) {
1439 motion_x[k] = motion_x[0];
1440 motion_y[k] = motion_y[0];
1441 }
1442
1443 /* no vector maintenance (last vector remains the
1444 * last vector) */
1445 break;
1446
1447 case MODE_INTER_PRIOR_LAST:
1448 /* all 6 fragments use the motion vector prior to the
1449 * last motion vector */
1450 motion_x[0] = prior_last_motion_x;
1451 motion_y[0] = prior_last_motion_y;
1452 for (k = 1; k < 6; k++) {
1453 motion_x[k] = motion_x[0];
1454 motion_y[k] = motion_y[0];
1455 }
1456
1457 /* vector maintenance */
1458 prior_last_motion_x = last_motion_x;
1459 prior_last_motion_y = last_motion_y;
1460 last_motion_x = motion_x[0];
1461 last_motion_y = motion_y[0];
1462 break;
1463 }
1464
1465 /* assign the motion vectors to the correct fragments */
1466 debug_vectors(" vectors for macroblock starting @ fragment %d (coding method %d):\n",
1467 current_fragment,
1468 s->all_fragments[current_fragment].coding_method);
1469 for (k = 0; k < 6; k++) {
1470 current_fragment =
1471 s->macroblock_fragments[current_macroblock * 6 + k];
1472 s->all_fragments[current_fragment].motion_x = motion_x[k];
1473 s->all_fragments[current_fragment].motion_x = motion_y[k];
1474 debug_vectors(" vector %d: fragment %d = (%d, %d)\n",
1475 k, current_fragment, motion_x[k], motion_y[k]);
1476 }
1477 }
1478 }
1479 }
1480 }
1481
1482 /*
1483 * This function is called by unpack_dct_coeffs() to extract the VLCs from
1484 * the bitstream. The VLCs encode tokens which are used to unpack DCT
1485 * data. This function unpacks all the VLCs for either the Y plane or both
1486 * C planes, and is called for DC coefficients or different AC coefficient
1487 * levels (since different coefficient types require different VLC tables.
1488 *
1489 * This function returns a residual eob run. E.g, if a particular token gave
1490 * instructions to EOB the next 5 fragments and there were only 2 fragments
1491 * left in the current fragment range, 3 would be returned so that it could
1492 * be passed into the next call to this same function.
1493 */
1494 static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
1495 VLC *table, int coeff_index,
1496 int first_fragment, int last_fragment,
1497 int eob_run)
1498 {
1499 int i;
1500 int token;
1501 int zero_run;
1502 DCTELEM coeff;
1503 Vp3Fragment *fragment;
1504
1505 for (i = first_fragment; i < last_fragment; i++) {
1506
1507 fragment = &s->all_fragments[s->coded_fragment_list[i]];
1508 if (fragment->coeff_count > coeff_index)
1509 continue;
1510
1511 if (!eob_run) {
1512 /* decode a VLC into a token */
1513 token = get_vlc2(gb, table->table, 5, 3);
1514 debug_vlc(" token = %2d, ", token);
1515 /* use the token to get a zero run, a coefficient, and an eob run */
1516 unpack_token(gb, token, &zero_run, &coeff, &eob_run);
1517 }
1518
1519 if (!eob_run) {
1520 fragment->coeff_count += zero_run;
1521 if (fragment->coeff_count < 64)
1522 fragment->coeffs[fragment->coeff_count++] = coeff;
1523 debug_vlc(" fragment %d coeff = %d\n",
1524 s->coded_fragment_list[i], fragment->coeffs[coeff_index]);
1525 } else {
1526 fragment->last_coeff = fragment->coeff_count;
1527 fragment->coeff_count = 64;
1528 debug_vlc(" fragment %d eob with %d coefficients\n",
1529 s->coded_fragment_list[i], fragment->last_coeff);
1530 eob_run--;
1531 }
1532 }
1533
1534 return eob_run;
1535 }
1536
1537 /*
1538 * This function unpacks all of the DCT coefficient data from the
1539 * bitstream.
1540 */
1541 static void unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
1542 {
1543 int i;
1544 int dc_y_table;
1545 int dc_c_table;
1546 int ac_y_table;
1547 int ac_c_table;
1548 int residual_eob_run = 0;
1549
1550 /* for the binary search */
1551 int left, middle, right, found;
1552 /* this indicates the first fragment of the color plane data */
1553 int plane_split = 0;
1554
1555 debug_vp3(" vp3: unpacking DCT coefficients\n");
1556
1557 /* find the plane split (the first color plane fragment) using a binary
1558 * search; test the boundaries first */
1559 if (s->coded_fragment_list_index == 0)
1560 return;
1561 if (s->u_fragment_start <= s->coded_fragment_list[0])
1562 plane_split = 0; /* this means no Y fragments */
1563 else if (s->coded_fragment_list[s->coded_fragment_list_index - 1] >
1564 s->u_fragment_start) {
1565
1566 left = 0;
1567 right = s->coded_fragment_list_index - 1;
1568 found = 0;
1569 do {
1570 middle = (left + right + 1) / 2;
1571 if ((s->coded_fragment_list[middle] >= s->u_fragment_start) &&
1572 (s->coded_fragment_list[middle - 1] < s->u_fragment_start))
1573 found = 1;
1574 else if (s->coded_fragment_list[middle] < s->u_fragment_start)
1575 left = middle;
1576 else
1577 right = middle;
1578 } while (!found);
1579
1580 plane_split = middle;
1581 }
1582
1583 debug_vp3(" plane split @ index %d (fragment %d)\n", plane_split,
1584 s->coded_fragment_list[plane_split]);
1585
1586 /* fetch the DC table indices */
1587 dc_y_table = get_bits(gb, 4);
1588 dc_c_table = get_bits(gb, 4);
1589
1590 /* unpack the Y plane DC coefficients */
1591 debug_vp3(" vp3: unpacking Y plane DC coefficients using table %d\n",
1592 dc_y_table);
1593 residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_y_table], 0,
1594 0, plane_split, residual_eob_run);
1595
1596 /* unpack the C plane DC coefficients */
1597 debug_vp3(" vp3: unpacking C plane DC coefficients using table %d\n",
1598 dc_c_table);
1599 residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
1600 plane_split, s->coded_fragment_list_index, residual_eob_run);
1601
1602 /* fetch the level 1 AC table indices */
1603 ac_y_table = get_bits(gb, 4);
1604 ac_c_table = get_bits(gb, 4);
1605
1606 /* unpack the level 1 AC coefficients (coeffs 1-5) */
1607 for (i = 1; i <= 5; i++) {
1608
1609 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1610 i, ac_y_table);
1611 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_y_table], i,
1612 0, plane_split, residual_eob_run);
1613
1614 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1615 i, ac_c_table);
1616 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_c_table], i,
1617 plane_split, s->coded_fragment_list_index, residual_eob_run);
1618 }
1619
1620 /* unpack the level 2 AC coefficients (coeffs 6-14) */
1621 for (i = 6; i <= 14; i++) {
1622
1623 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1624 i, ac_y_table);
1625 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_y_table], i,
1626 0, plane_split, residual_eob_run);
1627
1628 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1629 i, ac_c_table);
1630 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_c_table], i,
1631 plane_split, s->coded_fragment_list_index, residual_eob_run);
1632 }
1633
1634 /* unpack the level 3 AC coefficients (coeffs 15-27) */
1635 for (i = 15; i <= 27; i++) {
1636
1637 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1638 i, ac_y_table);
1639 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_y_table], i,
1640 0, plane_split, residual_eob_run);
1641
1642 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1643 i, ac_c_table);
1644 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_c_table], i,
1645 plane_split, s->coded_fragment_list_index, residual_eob_run);
1646 }
1647
1648 /* unpack the level 4 AC coefficients (coeffs 28-63) */
1649 for (i = 28; i <= 63; i++) {
1650
1651 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1652 i, ac_y_table);
1653 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_y_table], i,
1654 0, plane_split, residual_eob_run);
1655
1656 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1657 i, ac_c_table);
1658 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_c_table], i,
1659 plane_split, s->coded_fragment_list_index, residual_eob_run);
1660 }
1661 }
1662
1663 /*
1664 * This function reverses the DC prediction for each coded fragment in
1665 * the frame. Much of this function is adapted directly from the original
1666 * VP3 source code.
1667 */
1668 #define COMPATIBLE_FRAME(x) \
1669 (compatible_frame[s->all_fragments[x].coding_method] == current_frame_type)
1670 #define FRAME_CODED(x) (s->all_fragments[x].coding_method != MODE_COPY)
1671 #define HIGHBITDUPPED(X) (((signed short) X) >> 15)
1672 static inline int iabs (int x) { return ((x < 0) ? -x : x); }
1673
1674 static void reverse_dc_prediction(Vp3DecodeContext *s,
1675 int first_fragment,
1676 int fragment_width,
1677 int fragment_height)
1678 {
1679
1680 #define PUL 8
1681 #define PU 4
1682 #define PUR 2
1683 #define PL 1
1684
1685 int x, y;
1686 int i = first_fragment;
1687
1688 /*
1689 * Fragment prediction groups:
1690 *
1691 * 32222222226
1692 * 10000000004
1693 * 10000000004
1694 * 10000000004
1695 * 10000000004
1696 *
1697 * Note: Groups 5 and 7 do not exist as it would mean that the
1698 * fragment's x coordinate is both 0 and (width - 1) at the same time.
1699 */
1700 int predictor_group;
1701 short predicted_dc;
1702
1703 /* validity flags for the left, up-left, up, and up-right fragments */
1704 int fl, ful, fu, fur;
1705
1706 /* DC values for the left, up-left, up, and up-right fragments */
1707 int vl, vul, vu, vur;
1708
1709 /* indices for the left, up-left, up, and up-right fragments */
1710 int l, ul, u, ur;
1711
1712 /*
1713 * The 6 fields mean:
1714 * 0: up-left multiplier
1715 * 1: up multiplier
1716 * 2: up-right multiplier
1717 * 3: left multiplier
1718 * 4: mask
1719 * 5: right bit shift divisor (e.g., 7 means >>=7, a.k.a. div by 128)
1720 */
1721 int predictor_transform[16][6] = {
1722 { 0, 0, 0, 0, 0, 0 },
1723 { 0, 0, 0, 1, 0, 0 }, // PL
1724 { 0, 0, 1, 0, 0, 0 }, // PUR
1725 { 0, 0, 53, 75, 127, 7 }, // PUR|PL
1726 { 0, 1, 0, 0, 0, 0 }, // PU
1727 { 0, 1, 0, 1, 1, 1 }, // PU|PL
1728 { 0, 1, 0, 0, 0, 0 }, // PU|PUR
1729 { 0, 0, 53, 75, 127, 7 }, // PU|PUR|PL
1730 { 1, 0, 0, 0, 0, 0 }, // PUL
1731 { 0, 0, 0, 1, 0, 0 }, // PUL|PL
1732 { 1, 0, 1, 0, 1, 1 }, // PUL|PUR
1733 { 0, 0, 53, 75, 127, 7 }, // PUL|PUR|PL
1734 { 0, 1, 0, 0, 0, 0 }, // PUL|PU
1735 {-26, 29, 0, 29, 31, 5 }, // PUL|PU|PL
1736 { 3, 10, 3, 0, 15, 4 }, // PUL|PU|PUR
1737 {-26, 29, 0, 29, 31, 5 } // PUL|PU|PUR|PL
1738 };
1739
1740 /* This table shows which types of blocks can use other blocks for
1741 * prediction. For example, INTRA is the only mode in this table to
1742 * have a frame number of 0. That means INTRA blocks can only predict
1743 * from other INTRA blocks. There are 2 golden frame coding types;
1744 * blocks encoding in these modes can only predict from other blocks
1745 * that were encoded with these 1 of these 2 modes. */
1746 unsigned char compatible_frame[8] = {
1747 1, /* MODE_INTER_NO_MV */
1748 0, /* MODE_INTRA */
1749 1, /* MODE_INTER_PLUS_MV */
1750 1, /* MODE_INTER_LAST_MV */
1751 1, /* MODE_INTER_PRIOR_MV */
1752 2, /* MODE_USING_GOLDEN */
1753 2, /* MODE_GOLDEN_MV */
1754 1 /* MODE_INTER_FOUR_MV */
1755 };
1756 int current_frame_type;
1757
1758 /* there is a last DC predictor for each of the 3 frame types */
1759 short last_dc[3];
1760
1761 int transform = 0;
1762
1763 debug_vp3(" vp3: reversing DC prediction\n");
1764
1765 vul = vu = vur = vl = 0;
1766 last_dc[0] = last_dc[1] = last_dc[2] = 0;
1767
1768 /* for each fragment row... */
1769 for (y = 0; y < fragment_height; y++) {
1770
1771 /* for each fragment in a row... */
1772 for (x = 0; x < fragment_width; x++, i++) {
1773
1774 /* reverse prediction if this block was coded */
1775 if (s->all_fragments[i].coding_method != MODE_COPY) {
1776
1777 current_frame_type =
1778 compatible_frame[s->all_fragments[i].coding_method];
1779 predictor_group = (x == 0) + ((y == 0) << 1) +
1780 ((x + 1 == fragment_width) << 2);
1781 debug_dc_pred(" frag %d: group %d, orig DC = %d, ",
1782 i, predictor_group, s->all_fragments[i].coeffs[0]);
1783
1784 switch (predictor_group) {
1785
1786 case 0:
1787 /* main body of fragments; consider all 4 possible
1788 * fragments for prediction */
1789
1790 /* calculate the indices of the predicting fragments */
1791 ul = i - fragment_width - 1;
1792 u = i - fragment_width;
1793 ur = i - fragment_width + 1;
1794 l = i - 1;
1795
1796 /* fetch the DC values for the predicting fragments */
1797 vul = s->all_fragments[ul].coeffs[0];
1798 vu = s->all_fragments[u].coeffs[0];
1799 vur = s->all_fragments[ur].coeffs[0];
1800 vl = s->all_fragments[l].coeffs[0];
1801
1802 /* figure out which fragments are valid */
1803 ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul);
1804 fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
1805 fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur);
1806 fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
1807
1808 /* decide which predictor transform to use */
1809 transform = (fl*PL) | (fu*PU) | (ful*PUL) | (fur*PUR);
1810
1811 break;
1812
1813 case 1:
1814 /* left column of fragments, not including top corner;
1815 * only consider up and up-right fragments */
1816
1817 /* calculate the indices of the predicting fragments */
1818 u = i - fragment_width;
1819 ur = i - fragment_width + 1;
1820
1821 /* fetch the DC values for the predicting fragments */
1822 vu = s->all_fragments[u].coeffs[0];
1823 vur = s->all_fragments[ur].coeffs[0];
1824
1825 /* figure out which fragments are valid */
1826 fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur);
1827 fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
1828
1829 /* decide which predictor transform to use */
1830 transform = (fu*PU) | (fur*PUR);
1831
1832 break;
1833
1834 case 2:
1835 case 6:
1836 /* top row of fragments, not including top-left frag;
1837 * only consider the left fragment for prediction */
1838
1839 /* calculate the indices of the predicting fragments */
1840 l = i - 1;
1841
1842 /* fetch the DC values for the predicting fragments */
1843 vl = s->all_fragments[l].coeffs[0];
1844
1845 /* figure out which fragments are valid */
1846 fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
1847
1848 /* decide which predictor transform to use */
1849 transform = (fl*PL);
1850
1851 break;
1852
1853 case 3:
1854 /* top-left fragment */
1855
1856 /* nothing to predict from in this case */
1857 transform = 0;
1858
1859 break;
1860
1861 case 4:
1862 /* right column of fragments, not including top corner;
1863 * consider up-left, up, and left fragments for
1864 * prediction */
1865
1866 /* calculate the indices of the predicting fragments */
1867 ul = i - fragment_width - 1;
1868 u = i - fragment_width;
1869 l = i - 1;
1870
1871 /* fetch the DC values for the predicting fragments */
1872 vul = s->all_fragments[ul].coeffs[0];
1873 vu = s->all_fragments[u].coeffs[0];
1874 vl = s->all_fragments[l].coeffs[0];
1875
1876 /* figure out which fragments are valid */
1877 ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul);
1878 fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
1879 fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
1880
1881 /* decide which predictor transform to use */
1882 transform = (fl*PL) | (fu*PU) | (ful*PUL);
1883
1884 break;
1885
1886 }
1887
1888 debug_dc_pred("transform = %d, ", transform);
1889
1890 if (transform == 0) {
1891
1892 /* if there were no fragments to predict from, use last
1893 * DC saved */
1894 s->all_fragments[i].coeffs[0] += last_dc[current_frame_type];
1895 debug_dc_pred("from last DC (%d) = %d\n",
1896 current_frame_type, s->all_fragments[i].coeffs[0]);
1897
1898 } else {
1899
1900 /* apply the appropriate predictor transform */
1901 predicted_dc =
1902 (predictor_transform[transform][0] * vul) +
1903 (predictor_transform[transform][1] * vu) +
1904 (predictor_transform[transform][2] * vur) +
1905 (predictor_transform[transform][3] * vl);
1906
1907 /* if there is a shift value in the transform, add
1908 * the sign bit before the shift */
1909 if (predictor_transform[transform][5] != 0) {
1910 predicted_dc += ((predicted_dc >> 15) &
1911 predictor_transform[transform][4]);
1912 predicted_dc >>= predictor_transform[transform][5];
1913 }
1914
1915 /* check for outranging on the [ul u l] and
1916 * [ul u ur l] predictors */
1917 if ((transform == 13) || (transform == 15)) {
1918 if (iabs(predicted_dc - vu) > 128)
1919 predicted_dc = vu;
1920 else if (iabs(predicted_dc - vl) > 128)
1921 predicted_dc = vl;
1922 else if (iabs(predicted_dc - vul) > 128)
1923 predicted_dc = vul;
1924 }
1925
1926 /* at long last, apply the predictor */
1927 s->all_fragments[i].coeffs[0] += predicted_dc;
1928 debug_dc_pred("from pred DC = %d\n",
1929 s->all_fragments[i].coeffs[0]);
1930 }
1931
1932 /* save the DC */
1933 last_dc[current_frame_type] = s->all_fragments[i].coeffs[0];
1934 }
1935 }
1936 }
1937 }
1938
1939 /*
1940 * This function performs the final rendering of each fragment's data
1941 * onto the output frame.
1942 */
1943 static void render_fragments(Vp3DecodeContext *s,
1944 int first_fragment,
1945 int fragment_width,
1946 int fragment_height,
1947 int plane /* 0 = Y, 1 = U, 2 = V */)
1948 {
1949 int x, y;
1950 int m, n;
1951 int i = first_fragment;
1952 int j;
1953 int16_t *dequantizer;
1954 DCTELEM dequant_block[64];
1955 unsigned char *output_plane;
1956 unsigned char *last_plane;
1957 unsigned char *golden_plane;
1958 int stride;
1959
1960 debug_vp3(" vp3: rendering final fragments for %s\n",
1961 (plane == 0) ? "Y plane" : (plane == 1) ? "U plane" : "V plane");
1962
1963 /* set up plane-specific parameters */
1964 if (plane == 0) {
1965 dequantizer = s->intra_y_dequant;
1966 output_plane = s->current_frame.data[0];
1967 last_plane = s->last_frame.data[0];
1968 golden_plane = s->golden_frame.data[0];
1969 stride = -s->current_frame.linesize[0];
1970 } else if (plane == 1) {
1971 dequantizer = s->intra_c_dequant;
1972 output_plane = s->current_frame.data[1];
1973 last_plane = s->last_frame.data[1];
1974 golden_plane = s->golden_frame.data[1];
1975 stride = -s->current_frame.linesize[1];
1976 } else {
1977 dequantizer = s->intra_c_dequant;
1978 output_plane = s->current_frame.data[2];
1979 last_plane = s->last_frame.data[2];
1980 golden_plane = s->golden_frame.data[2];
1981 stride = -s->current_frame.linesize[2];
1982 }
1983
1984 /* for each fragment row... */
1985 for (y = 0; y < fragment_height; y++) {
1986
1987 /* for each fragment in a row... */
1988 for (x = 0; x < fragment_width; x++, i++) {
1989
1990 /* transform if this block was coded */
1991 if (s->all_fragments[i].coding_method == MODE_INTRA) {
1992 /* dequantize the DCT coefficients */
1993 for (j = 0; j < 64; j++)
1994 dequant_block[dequant_index[j]] =
1995 s->all_fragments[i].coeffs[j] *
1996 dequantizer[j];
1997 dequant_block[0] += 1024;
1998
1999 debug_idct("fragment %d:\n", i);
2000 debug_idct("dequantized block:\n");
2001 for (m = 0; m < 8; m++) {
2002 for (n = 0; n < 8; n++) {
2003 debug_idct(" %5d", dequant_block[m * 8 + n]);
2004 }
2005 debug_idct("\n");
2006 }
2007 debug_idct("\n");
2008
2009 /* invert DCT and place in final output */
2010 s->dsp.idct_put(
2011 output_plane + s->all_fragments[i].first_pixel,
2012 stride, dequant_block);
2013
2014 /*
2015 debug_idct("idct block:\n");
2016 for (m = 0; m < 8; m++) {
2017 for (n = 0; n < 8; n++) {
2018 debug_idct(" %3d", pixels[m * 8 + n]);
2019 }
2020 debug_idct("\n");
2021 }
2022 debug_idct("\n");
2023 */
2024 } else if (s->all_fragments[i].coding_method == MODE_COPY) {
2025
2026 /* copy directly from the previous frame */
2027 for (m = 0; m < 8; m++)
2028 memcpy(
2029 output_plane + s->all_fragments[i].first_pixel + stride * m,
2030 last_plane + s->all_fragments[i].first_pixel + stride * m,
2031 8);
2032
2033 } else {
2034
2035 /* carry out the motion compensation */
2036
2037 }
2038 }
2039 }
2040
2041 emms_c();
2042
2043 }
2044
2045 /*
2046 * This function computes the first pixel addresses for each fragment.
2047 * This function needs to be invoked after the first frame is allocated
2048 * so that it has access to the plane strides.
2049 */
2050 static void vp3_calculate_pixel_addresses(Vp3DecodeContext *s)
2051 {
2052
2053 int i, x, y;
2054
2055 /* figure out the first pixel addresses for each of the fragments */
2056 /* Y plane */
2057 i = 0;
2058 for (y = s->fragment_height; y > 0; y--) {
2059 for (x = 0; x < s->fragment_width; x++) {
2060 s->all_fragments[i++].first_pixel =
2061 s->golden_frame.linesize[0] * y * FRAGMENT_PIXELS -
2062 s->golden_frame.linesize[0] +
2063 x * FRAGMENT_PIXELS;
2064 debug_init(" fragment %d, first pixel @ %d\n",
2065 i-1, s->all_fragments[i-1].first_pixel);
2066 }
2067 }
2068
2069 /* U plane */
2070 i = s->u_fragment_start;
2071 for (y = s->fragment_height / 2; y > 0; y--) {
2072 for (x = 0; x < s->fragment_width / 2; x++) {
2073 s->all_fragments[i++].first_pixel =
2074 s->golden_frame.linesize[1] * y * FRAGMENT_PIXELS -
2075 s->golden_frame.linesize[1] +
2076 x * FRAGMENT_PIXELS;
2077 debug_init(" fragment %d, first pixel @ %d\n",
2078 i-1, s->all_fragments[i-1].first_pixel);
2079 }
2080 }
2081
2082 /* V plane */
2083 i = s->v_fragment_start;
2084 for (y = s->fragment_height / 2; y > 0; y--) {
2085 for (x = 0; x < s->fragment_width / 2; x++) {
2086 s->all_fragments[i++].first_pixel =
2087 s->golden_frame.linesize[2] * y * FRAGMENT_PIXELS -
2088 s->golden_frame.linesize[2] +
2089 x * FRAGMENT_PIXELS;
2090 debug_init(" fragment %d, first pixel @ %d\n",
2091 i-1, s->all_fragments[i-1].first_pixel);
2092 }
2093 }
2094 }
2095
2096 /*
2097 * This is the ffmpeg/libavcodec API init function.
2098 */
2099 static int vp3_decode_init(AVCodecContext *avctx)
2100 {
2101 Vp3DecodeContext *s = avctx->priv_data;
2102 int i;
2103
2104 s->avctx = avctx;
2105 s->width = avctx->width;
2106 s->height = avctx->height;
2107 avctx->pix_fmt = PIX_FMT_YUV420P;
2108 avctx->has_b_frames = 0;
2109 dsputil_init(&s->dsp, avctx);
2110
2111 /* initialize to an impossible value which will force a recalculation
2112 * in the first frame decode */
2113 s->quality_index = -1;
2114
2115 s->superblock_width = (s->width + 31) / 32;
2116 s->superblock_height = (s->height + 31) / 32;
2117 s->superblock_count = s->superblock_width * s->superblock_height * 3 / 2;
2118 s->u_superblock_start = s->superblock_width * s->superblock_height;
2119 s->v_superblock_start = s->superblock_width * s->superblock_height * 5 / 4;
2120 s->superblock_coding = av_malloc(s->superblock_count);
2121
2122 s->macroblock_width = (s->width + 15) / 16;
2123 s->macroblock_height = (s->height + 15) / 16;
2124 s->macroblock_count = s->macroblock_width * s->macroblock_height;
2125
2126 s->fragment_width = s->width / FRAGMENT_PIXELS;
2127 s->fragment_height = s->height / FRAGMENT_PIXELS;
2128
2129 /* fragment count covers all 8x8 blocks for all 3 planes */
2130 s->fragment_count = s->fragment_width * s->fragment_height * 3 / 2;
2131 s->u_fragment_start = s->fragment_width * s->fragment_height;
2132 s->v_fragment_start = s->fragment_width * s->fragment_height * 5 / 4;
2133
2134 debug_init(" width: %d x %d\n", s->width, s->height);
2135 debug_init(" superblocks: %d x %d, %d total\n",
2136 s->superblock_width, s->superblock_height, s->superblock_count);
2137 debug_init(" macroblocks: %d x %d, %d total\n",
2138 s->macroblock_width, s->macroblock_height, s->macroblock_count);
2139 debug_init(" %d fragments, %d x %d, u starts @ %d, v starts @ %d\n",
2140 s->fragment_count,
2141 s->fragment_width,
2142 s->fragment_height,
2143 s->u_fragment_start,
2144 s->v_fragment_start);
2145
2146 s->all_fragments = av_malloc(s->fragment_count * sizeof(Vp3Fragment));
2147 s->coded_fragment_list = av_malloc(s->fragment_count * sizeof(int));
2148 s->pixel_addresses_inited = 0;
2149
2150 /* init VLC tables */
2151 for (i = 0; i < 16; i++) {
2152
2153 /* Dc histograms */
2154 init_vlc(&s->dc_vlc[i], 5, 32,
2155 &dc_bias[i][0][1], 4, 2,
2156 &dc_bias[i][0][0], 4, 2);
2157
2158 /* level 1 AC histograms */
2159 init_vlc(&s->ac_vlc_1[i], 5, 32,
2160 &ac_bias_0[i][0][1], 4, 2,
2161 &ac_bias_0[i][0][0], 4, 2);
2162
2163 /* level 2 AC histograms */
2164 init_vlc(&s->ac_vlc_2[i], 5, 32,
2165 &ac_bias_1[i][0][1], 4, 2,
2166 &ac_bias_1[i][0][0], 4, 2);
2167
2168 /* level 3 AC histograms */
2169 init_vlc(&s->ac_vlc_3[i], 5, 32,
2170 &ac_bias_2[i][0][1], 4, 2,
2171 &ac_bias_2[i][0][0], 4, 2);
2172
2173 /* level 4 AC histograms */
2174 init_vlc(&s->ac_vlc_4[i], 5, 32,
2175 &ac_bias_3[i][0][1], 4, 2,
2176 &ac_bias_3[i][0][0], 4, 2);
2177 }
2178
2179 /* build quantization table */
2180 for (i = 0; i < 64; i++)
2181 quant_index[dequant_index[i]] = i;
2182
2183 /* work out the block mapping tables */
2184 s->superblock_fragments = av_malloc(s->superblock_count * 16 * sizeof(int));
2185 s->superblock_macroblocks = av_malloc(s->superblock_count * 4 * sizeof(int));
2186 s->macroblock_fragments = av_malloc(s->macroblock_count * 6 * sizeof(int));
2187 s->macroblock_coded = av_malloc(s->macroblock_count + 1);
2188 init_block_mapping(s);
2189
2190 /* make sure that frames are available to be freed on the first decode */
2191 if(avctx->get_buffer(avctx, &s->golden_frame) < 0) {
2192 printf("vp3: get_buffer() failed\n");
2193 return -1;
2194 }
2195
2196 return 0;
2197 }
2198
2199 /*
2200 * This is the ffmpeg/libavcodec API frame decode function.
2201 */
2202 static int vp3_decode_frame(AVCodecContext *avctx,
2203 void *data, int *data_size,
2204 uint8_t *buf, int buf_size)
2205 {
2206 Vp3DecodeContext *s = avctx->priv_data;
2207 GetBitContext gb;
2208 static int counter = 0;
2209
2210 *data_size = 0;
2211
2212 init_get_bits(&gb, buf, buf_size * 8);
2213
2214 s->keyframe = get_bits(&gb, 1);
2215 s->keyframe ^= 1;
2216 skip_bits(&gb, 1);
2217 s->last_quality_index = s->quality_index;
2218 s->quality_index = get_bits(&gb, 6);
2219 if (s->quality_index != s->last_quality_index)
2220 init_dequantizer(s);
2221
2222 debug_vp3(" VP3 frame #%d: Q index = %d", counter, s->quality_index);
2223 counter++;
2224
2225 if (s->keyframe) {
2226 /* release the previous golden frame and get a new one */
2227 avctx->release_buffer(avctx, &s->golden_frame);
2228
2229 s->golden_frame.reference = 0;
2230 if(avctx->get_buffer(avctx, &s->golden_frame) < 0) {
2231 printf("vp3: get_buffer() failed\n");
2232 return -1;
2233 }
2234
2235 /* golden frame is also the current frame */
2236 memcpy(&s->current_frame, &s->golden_frame, sizeof(AVFrame));
2237
2238 /* time to figure out pixel addresses? */
2239 if (!s->pixel_addresses_inited)
2240 vp3_calculate_pixel_addresses(s);
2241
2242 } else {
2243
2244 /* allocate a new current frame */
2245 s->current_frame.reference = 0;
2246 if(avctx->get_buffer(avctx, &s->current_frame) < 0) {
2247 printf("vp3: get_buffer() failed\n");
2248 return -1;
2249 }
2250
2251 }
2252
2253 if (s->keyframe) {
2254 debug_vp3(", keyframe\n");
2255 /* skip the other 2 header bytes for now */
2256 skip_bits(&gb, 16);
2257 } else
2258 debug_vp3("\n");
2259
2260 init_frame(s, &gb);
2261
2262 unpack_superblocks(s, &gb);
2263 unpack_modes(s, &gb);
2264 unpack_vectors(s, &gb);
2265 unpack_dct_coeffs(s, &gb);
2266
2267 reverse_dc_prediction(s, 0, s->fragment_width, s->fragment_height);
2268 reverse_dc_prediction(s, s->u_fragment_start,
2269 s->fragment_width / 2, s->fragment_height / 2);
2270 reverse_dc_prediction(s, s->v_fragment_start,
2271 s->fragment_width / 2, s->fragment_height / 2);
2272
2273 render_fragments(s, 0, s->fragment_width, s->fragment_height, 0);
2274 render_fragments(s, s->u_fragment_start,
2275 s->fragment_width / 2, s->fragment_height / 2, 1);
2276 render_fragments(s, s->v_fragment_start,
2277 s->fragment_width / 2, s->fragment_height / 2, 2);
2278
2279 *data_size=sizeof(AVFrame);
2280 *(AVFrame*)data= s->current_frame;
2281
2282 /* release the last frame, if it was allocated */
2283 avctx->release_buffer(avctx, &s->last_frame);
2284
2285 /* shuffle frames (last = current) */
2286 memcpy(&s->last_frame, &s->current_frame, sizeof(AVFrame));
2287
2288 return buf_size;
2289 }
2290
2291 /*
2292 * This is the ffmpeg/libavcodec API module cleanup function.
2293 */
2294 static int vp3_decode_end(AVCodecContext *avctx)
2295 {
2296 Vp3DecodeContext *s = avctx->priv_data;
2297
2298 av_free(s->all_fragments);
2299 av_free(s->coded_fragment_list);
2300 av_free(s->superblock_fragments);
2301 av_free(s->superblock_macroblocks);
2302 av_free(s->macroblock_fragments);
2303 av_free(s->macroblock_coded);
2304
2305 /* release all frames */
2306 avctx->release_buffer(avctx, &s->golden_frame);
2307 avctx->release_buffer(avctx, &s->last_frame);
2308 avctx->release_buffer(avctx, &s->current_frame);
2309
2310 return 0;
2311 }
2312
2313 AVCodec vp3_decoder = {
2314 "vp3",
2315 CODEC_TYPE_VIDEO,
2316 CODEC_ID_VP3,
2317 sizeof(Vp3DecodeContext),
2318 vp3_decode_init,
2319 NULL,
2320 vp3_decode_end,
2321 vp3_decode_frame,
2322 0,
2323 NULL
2324 };