91e6fbb111980b157c7daed1480f46a0a160ba4c
[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
39 #include "vp3data.h"
40
41 #define FRAGMENT_PIXELS 8
42
43 /*
44 * Debugging Variables
45 *
46 * Define one or more of the following compile-time variables to 1 to obtain
47 * elaborate information about certain aspects of the decoding process.
48 *
49 * KEYFRAMES_ONLY: set this to 1 to only see keyframes (VP3 slideshow mode)
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 KEYFRAMES_ONLY 0
63
64 #define DEBUG_VP3 0
65 #define DEBUG_INIT 0
66 #define DEBUG_DEQUANTIZERS 0
67 #define DEBUG_BLOCK_CODING 0
68 #define DEBUG_MODES 0
69 #define DEBUG_VECTORS 0
70 #define DEBUG_TOKEN 0
71 #define DEBUG_VLC 0
72 #define DEBUG_DC_PRED 0
73 #define DEBUG_IDCT 0
74
75 #if DEBUG_VP3
76 #define debug_vp3 printf
77 #else
78 static inline void debug_vp3(const char *format, ...) { }
79 #endif
80
81 #if DEBUG_INIT
82 #define debug_init printf
83 #else
84 static inline void debug_init(const char *format, ...) { }
85 #endif
86
87 #if DEBUG_DEQUANTIZERS
88 #define debug_dequantizers printf
89 #else
90 static inline void debug_dequantizers(const char *format, ...) { }
91 #endif
92
93 #if DEBUG_BLOCK_CODING
94 #define debug_block_coding printf
95 #else
96 static inline void debug_block_coding(const char *format, ...) { }
97 #endif
98
99 #if DEBUG_MODES
100 #define debug_modes printf
101 #else
102 static inline void debug_modes(const char *format, ...) { }
103 #endif
104
105 #if DEBUG_VECTORS
106 #define debug_vectors printf
107 #else
108 static inline void debug_vectors(const char *format, ...) { }
109 #endif
110
111 #if DEBUG_TOKEN
112 #define debug_token printf
113 #else
114 static inline void debug_token(const char *format, ...) { }
115 #endif
116
117 #if DEBUG_VLC
118 #define debug_vlc printf
119 #else
120 static inline void debug_vlc(const char *format, ...) { }
121 #endif
122
123 #if DEBUG_DC_PRED
124 #define debug_dc_pred printf
125 #else
126 static inline void debug_dc_pred(const char *format, ...) { }
127 #endif
128
129 #if DEBUG_IDCT
130 #define debug_idct printf
131 #else
132 static inline void debug_idct(const char *format, ...) { }
133 #endif
134
135 typedef struct Vp3Fragment {
136 DCTELEM coeffs[64];
137 int coding_method;
138 int coeff_count;
139 int last_coeff;
140 int motion_x;
141 int motion_y;
142 /* this indicates which ffmpeg put_pixels() function to use:
143 * 00b = no halfpel, 01b = x halfpel, 10b = y halfpel, 11b = both halfpel */
144 int motion_halfpel_index;
145 /* address of first pixel taking into account which plane the fragment
146 * lives on as well as the plane stride */
147 int first_pixel;
148 /* this is the macroblock that the fragment belongs to */
149 int macroblock;
150 } Vp3Fragment;
151
152 #define SB_NOT_CODED 0
153 #define SB_PARTIALLY_CODED 1
154 #define SB_FULLY_CODED 2
155
156 #define MODE_INTER_NO_MV 0
157 #define MODE_INTRA 1
158 #define MODE_INTER_PLUS_MV 2
159 #define MODE_INTER_LAST_MV 3
160 #define MODE_INTER_PRIOR_LAST 4
161 #define MODE_USING_GOLDEN 5
162 #define MODE_GOLDEN_MV 6
163 #define MODE_INTER_FOURMV 7
164 #define CODING_MODE_COUNT 8
165
166 /* special internal mode */
167 #define MODE_COPY 8
168
169 /* There are 6 preset schemes, plus a free-form scheme */
170 static int ModeAlphabet[7][CODING_MODE_COUNT] =
171 {
172 /* this is the custom scheme */
173 { 0, 0, 0, 0, 0, 0, 0, 0 },
174
175 /* scheme 1: Last motion vector dominates */
176 { MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
177 MODE_INTER_PLUS_MV, MODE_INTER_NO_MV,
178 MODE_INTRA, MODE_USING_GOLDEN,
179 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
180
181 /* scheme 2 */
182 { MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
183 MODE_INTER_NO_MV, MODE_INTER_PLUS_MV,
184 MODE_INTRA, MODE_USING_GOLDEN,
185 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
186
187 /* scheme 3 */
188 { MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
189 MODE_INTER_PRIOR_LAST, MODE_INTER_NO_MV,
190 MODE_INTRA, MODE_USING_GOLDEN,
191 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
192
193 /* scheme 4 */
194 { MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
195 MODE_INTER_NO_MV, MODE_INTER_PRIOR_LAST,
196 MODE_INTRA, MODE_USING_GOLDEN,
197 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
198
199 /* scheme 5: No motion vector dominates */
200 { MODE_INTER_NO_MV, MODE_INTER_LAST_MV,
201 MODE_INTER_PRIOR_LAST, MODE_INTER_PLUS_MV,
202 MODE_INTRA, MODE_USING_GOLDEN,
203 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
204
205 /* scheme 6 */
206 { MODE_INTER_NO_MV, MODE_USING_GOLDEN,
207 MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
208 MODE_INTER_PLUS_MV, MODE_INTRA,
209 MODE_GOLDEN_MV, MODE_INTER_FOURMV },
210
211 };
212
213 #define MIN_DEQUANT_VAL 2
214
215 typedef struct Vp3DecodeContext {
216 AVCodecContext *avctx;
217 int width, height;
218 AVFrame golden_frame;
219 AVFrame last_frame;
220 AVFrame current_frame;
221 int keyframe;
222 DSPContext dsp;
223
224 int quality_index;
225 int last_quality_index;
226
227 int superblock_count;
228 int superblock_width;
229 int superblock_height;
230 int y_superblock_width;
231 int y_superblock_height;
232 int c_superblock_width;
233 int c_superblock_height;
234 int u_superblock_start;
235 int v_superblock_start;
236 unsigned char *superblock_coding;
237
238 int macroblock_count;
239 int macroblock_width;
240 int macroblock_height;
241
242 int fragment_count;
243 int fragment_width;
244 int fragment_height;
245
246 Vp3Fragment *all_fragments;
247 int u_fragment_start;
248 int v_fragment_start;
249
250 /* this is a list of indices into the all_fragments array indicating
251 * which of the fragments are coded */
252 int *coded_fragment_list;
253 int coded_fragment_list_index;
254 int pixel_addresses_inited;
255
256 VLC dc_vlc[16];
257 VLC ac_vlc_1[16];
258 VLC ac_vlc_2[16];
259 VLC ac_vlc_3[16];
260 VLC ac_vlc_4[16];
261
262 int16_t intra_y_dequant[64];
263 int16_t intra_c_dequant[64];
264 int16_t inter_dequant[64];
265
266 /* This table contains superblock_count * 16 entries. Each set of 16
267 * numbers corresponds to the fragment indices 0..15 of the superblock.
268 * An entry will be -1 to indicate that no entry corresponds to that
269 * index. */
270 int *superblock_fragments;
271
272 /* This table contains superblock_count * 4 entries. Each set of 4
273 * numbers corresponds to the macroblock indices 0..3 of the superblock.
274 * An entry will be -1 to indicate that no entry corresponds to that
275 * index. */
276 int *superblock_macroblocks;
277
278 /* This table contains macroblock_count * 6 entries. Each set of 6
279 * numbers corresponds to the fragment indices 0..5 which comprise
280 * the macroblock (4 Y fragments and 2 C fragments). */
281 int *macroblock_fragments;
282 /* This is an array that indicates how a particular macroblock
283 * is coded. */
284 unsigned char *macroblock_coding;
285
286 int first_coded_y_fragment;
287 int first_coded_c_fragment;
288 int last_coded_y_fragment;
289 int last_coded_c_fragment;
290
291 } Vp3DecodeContext;
292
293 /************************************************************************
294 * VP3 specific functions
295 ************************************************************************/
296
297 /*
298 * This function sets up all of the various blocks mappings:
299 * superblocks <-> fragments, macroblocks <-> fragments,
300 * superblocks <-> macroblocks
301 *
302 * Returns 0 is successful; returns 1 if *anything* went wrong.
303 */
304 static int init_block_mapping(Vp3DecodeContext *s)
305 {
306 int i, j;
307 signed int hilbert_walk_y[16];
308 signed int hilbert_walk_c[16];
309 signed int hilbert_walk_mb[4];
310
311 int current_fragment = 0;
312 int current_width = 0;
313 int current_height = 0;
314 int right_edge = 0;
315 int bottom_edge = 0;
316 int superblock_row_inc = 0;
317 int *hilbert = NULL;
318 int mapping_index = 0;
319
320 int current_macroblock;
321 int c_fragment;
322
323 signed char travel_width[16] = {
324 1, 1, 0, -1,
325 0, 0, 1, 0,
326 1, 0, 1, 0,
327 0, -1, 0, 1
328 };
329
330 signed char travel_height[16] = {
331 0, 0, 1, 0,
332 1, 1, 0, -1,
333 0, 1, 0, -1,
334 -1, 0, -1, 0
335 };
336
337 signed char travel_width_mb[4] = {
338 1, 0, 1, 0
339 };
340
341 signed char travel_height_mb[4] = {
342 0, 1, 0, -1
343 };
344
345 debug_vp3(" vp3: initialize block mapping tables\n");
346
347 /* figure out hilbert pattern per these frame dimensions */
348 hilbert_walk_y[0] = 1;
349 hilbert_walk_y[1] = 1;
350 hilbert_walk_y[2] = s->fragment_width;
351 hilbert_walk_y[3] = -1;
352 hilbert_walk_y[4] = s->fragment_width;
353 hilbert_walk_y[5] = s->fragment_width;
354 hilbert_walk_y[6] = 1;
355 hilbert_walk_y[7] = -s->fragment_width;
356 hilbert_walk_y[8] = 1;
357 hilbert_walk_y[9] = s->fragment_width;
358 hilbert_walk_y[10] = 1;
359 hilbert_walk_y[11] = -s->fragment_width;
360 hilbert_walk_y[12] = -s->fragment_width;
361 hilbert_walk_y[13] = -1;
362 hilbert_walk_y[14] = -s->fragment_width;
363 hilbert_walk_y[15] = 1;
364
365 hilbert_walk_c[0] = 1;
366 hilbert_walk_c[1] = 1;
367 hilbert_walk_c[2] = s->fragment_width / 2;
368 hilbert_walk_c[3] = -1;
369 hilbert_walk_c[4] = s->fragment_width / 2;
370 hilbert_walk_c[5] = s->fragment_width / 2;
371 hilbert_walk_c[6] = 1;
372 hilbert_walk_c[7] = -s->fragment_width / 2;
373 hilbert_walk_c[8] = 1;
374 hilbert_walk_c[9] = s->fragment_width / 2;
375 hilbert_walk_c[10] = 1;
376 hilbert_walk_c[11] = -s->fragment_width / 2;
377 hilbert_walk_c[12] = -s->fragment_width / 2;
378 hilbert_walk_c[13] = -1;
379 hilbert_walk_c[14] = -s->fragment_width / 2;
380 hilbert_walk_c[15] = 1;
381
382 hilbert_walk_mb[0] = 1;
383 hilbert_walk_mb[1] = s->macroblock_width;
384 hilbert_walk_mb[2] = 1;
385 hilbert_walk_mb[3] = -s->macroblock_width;
386
387 /* iterate through each superblock (all planes) and map the fragments */
388 for (i = 0; i < s->superblock_count; i++) {
389 debug_init(" superblock %d (u starts @ %d, v starts @ %d)\n",
390 i, s->u_superblock_start, s->v_superblock_start);
391
392 /* time to re-assign the limits? */
393 if (i == 0) {
394
395 /* start of Y superblocks */
396 right_edge = s->fragment_width;
397 bottom_edge = s->fragment_height;
398 current_width = -1;
399 current_height = 0;
400 superblock_row_inc = 3 * s->fragment_width -
401 (s->y_superblock_width * 4 - s->fragment_width);
402 hilbert = hilbert_walk_y;
403
404 /* the first operation for this variable is to advance by 1 */
405 current_fragment = -1;
406
407 } else if (i == s->u_superblock_start) {
408
409 /* start of U superblocks */
410 right_edge = s->fragment_width / 2;
411 bottom_edge = s->fragment_height / 2;
412 current_width = -1;
413 current_height = 0;
414 superblock_row_inc = 3 * (s->fragment_width / 2) -
415 (s->c_superblock_width * 4 - s->fragment_width / 2);
416 hilbert = hilbert_walk_c;
417
418 /* the first operation for this variable is to advance by 1 */
419 current_fragment = s->u_fragment_start - 1;
420
421 } else if (i == s->v_superblock_start) {
422
423 /* start of V superblocks */
424 right_edge = s->fragment_width / 2;
425 bottom_edge = s->fragment_height / 2;
426 current_width = -1;
427 current_height = 0;
428 superblock_row_inc = 3 * (s->fragment_width / 2) -
429 (s->c_superblock_width * 4 - s->fragment_width / 2);
430 hilbert = hilbert_walk_c;
431
432 /* the first operation for this variable is to advance by 1 */
433 current_fragment = s->v_fragment_start - 1;
434
435 }
436
437 if (current_width >= right_edge - 1) {
438 /* reset width and move to next superblock row */
439 current_width = -1;
440 current_height += 4;
441
442 /* fragment is now at the start of a new superblock row */
443 current_fragment += superblock_row_inc;
444 }
445
446 /* iterate through all 16 fragments in a superblock */
447 for (j = 0; j < 16; j++) {
448 current_fragment += hilbert[j];
449 current_width += travel_width[j];
450 current_height += travel_height[j];
451
452 /* check if the fragment is in bounds */
453 if ((current_width < right_edge) &&
454 (current_height < bottom_edge)) {
455 s->superblock_fragments[mapping_index] = current_fragment;
456 debug_init(" mapping fragment %d to superblock %d, position %d (%d/%d x %d/%d)\n",
457 s->superblock_fragments[mapping_index], i, j,
458 current_width, right_edge, current_height, bottom_edge);
459 } else {
460 s->superblock_fragments[mapping_index] = -1;
461 debug_init(" superblock %d, position %d has no fragment (%d/%d x %d/%d)\n",
462 i, j,
463 current_width, right_edge, current_height, bottom_edge);
464 }
465
466 mapping_index++;
467 }
468 }
469
470 /* initialize the superblock <-> macroblock mapping; iterate through
471 * all of the Y plane superblocks to build this mapping */
472 right_edge = s->macroblock_width;
473 bottom_edge = s->macroblock_height;
474 current_width = -1;
475 current_height = 0;
476 superblock_row_inc = s->macroblock_width -
477 (s->y_superblock_width * 2 - s->macroblock_width);;
478 hilbert = hilbert_walk_mb;
479 mapping_index = 0;
480 current_macroblock = -1;
481 for (i = 0; i < s->u_superblock_start; i++) {
482
483 if (current_width >= right_edge - 1) {
484 /* reset width and move to next superblock row */
485 current_width = -1;
486 current_height += 2;
487
488 /* macroblock is now at the start of a new superblock row */
489 current_macroblock += superblock_row_inc;
490 }
491
492 /* iterate through each potential macroblock in the superblock */
493 for (j = 0; j < 4; j++) {
494 current_macroblock += hilbert_walk_mb[j];
495 current_width += travel_width_mb[j];
496 current_height += travel_height_mb[j];
497
498 /* check if the macroblock is in bounds */
499 if ((current_width < right_edge) &&
500 (current_height < bottom_edge)) {
501 s->superblock_macroblocks[mapping_index] = current_macroblock;
502 debug_init(" mapping macroblock %d to superblock %d, position %d (%d/%d x %d/%d)\n",
503 s->superblock_macroblocks[mapping_index], i, j,
504 current_width, right_edge, current_height, bottom_edge);
505 } else {
506 s->superblock_macroblocks[mapping_index] = -1;
507 debug_init(" superblock %d, position %d has no macroblock (%d/%d x %d/%d)\n",
508 i, j,
509 current_width, right_edge, current_height, bottom_edge);
510 }
511
512 mapping_index++;
513 }
514 }
515
516 /* initialize the macroblock <-> fragment mapping */
517 current_fragment = 0;
518 current_macroblock = 0;
519 mapping_index = 0;
520 for (i = 0; i < s->fragment_height; i += 2) {
521
522 for (j = 0; j < s->fragment_width; j += 2) {
523
524 debug_init(" macroblock %d contains fragments: ", current_macroblock);
525 s->all_fragments[current_fragment].macroblock = current_macroblock;
526 s->macroblock_fragments[mapping_index++] = current_fragment;
527 debug_init("%d ", current_fragment);
528
529 if (j + 1 < s->fragment_width) {
530 s->all_fragments[current_fragment + 1].macroblock = current_macroblock;
531 s->macroblock_fragments[mapping_index++] = current_fragment + 1;
532 debug_init("%d ", current_fragment + 1);
533 } else
534 s->macroblock_fragments[mapping_index++] = -1;
535
536 if (i + 1 < s->fragment_height) {
537 s->all_fragments[current_fragment + s->fragment_width].macroblock =
538 current_macroblock;
539 s->macroblock_fragments[mapping_index++] =
540 current_fragment + s->fragment_width;
541 debug_init("%d ", current_fragment + s->fragment_width);
542 } else
543 s->macroblock_fragments[mapping_index++] = -1;
544
545 if ((j + 1 < s->fragment_width) && (i + 1 < s->fragment_height)) {
546 s->all_fragments[current_fragment + s->fragment_width + 1].macroblock =
547 current_macroblock;
548 s->macroblock_fragments[mapping_index++] =
549 current_fragment + s->fragment_width + 1;
550 debug_init("%d ", current_fragment + s->fragment_width + 1);
551 } else
552 s->macroblock_fragments[mapping_index++] = -1;
553
554 /* C planes */
555 c_fragment = s->u_fragment_start +
556 (i * s->fragment_width / 4) + (j / 2);
557 s->all_fragments[c_fragment].macroblock = s->macroblock_count;
558 s->macroblock_fragments[mapping_index++] = c_fragment;
559 debug_init("%d ", c_fragment);
560
561 c_fragment = s->v_fragment_start +
562 (i * s->fragment_width / 4) + (j / 2);
563 s->all_fragments[c_fragment].macroblock = s->macroblock_count;
564 s->macroblock_fragments[mapping_index++] = c_fragment;
565 debug_init("%d ", c_fragment);
566
567 debug_init("\n");
568
569 if (j + 2 <= s->fragment_width)
570 current_fragment += 2;
571 else
572 current_fragment++;
573 current_macroblock++;
574 }
575
576 current_fragment += s->fragment_width;
577 }
578
579 return 0; /* successful path out */
580 }
581
582 /*
583 * This function unpacks a single token (which should be in the range 0..31)
584 * and returns a zero run (number of zero coefficients in current DCT matrix
585 * before next non-zero coefficient), the next DCT coefficient, and the
586 * number of consecutive, non-EOB'd DCT blocks to EOB.
587 */
588 static void unpack_token(GetBitContext *gb, int token, int *zero_run,
589 DCTELEM *coeff, int *eob_run)
590 {
591 int sign;
592
593 *zero_run = 0;
594 *eob_run = 0;
595 *coeff = 0;
596
597 debug_token(" vp3 token %d: ", token);
598 switch (token) {
599
600 case 0:
601 debug_token("DCT_EOB_TOKEN, EOB next block\n");
602 *eob_run = 1;
603 break;
604
605 case 1:
606 debug_token("DCT_EOB_PAIR_TOKEN, EOB next 2 blocks\n");
607 *eob_run = 2;
608 break;
609
610 case 2:
611 debug_token("DCT_EOB_TRIPLE_TOKEN, EOB next 3 blocks\n");
612 *eob_run = 3;
613 break;
614
615 case 3:
616 debug_token("DCT_REPEAT_RUN_TOKEN, ");
617 *eob_run = get_bits(gb, 2) + 4;
618 debug_token("EOB the next %d blocks\n", *eob_run);
619 break;
620
621 case 4:
622 debug_token("DCT_REPEAT_RUN2_TOKEN, ");
623 *eob_run = get_bits(gb, 3) + 8;
624 debug_token("EOB the next %d blocks\n", *eob_run);
625 break;
626
627 case 5:
628 debug_token("DCT_REPEAT_RUN3_TOKEN, ");
629 *eob_run = get_bits(gb, 4) + 16;
630 debug_token("EOB the next %d blocks\n", *eob_run);
631 break;
632
633 case 6:
634 debug_token("DCT_REPEAT_RUN4_TOKEN, ");
635 *eob_run = get_bits(gb, 12);
636 debug_token("EOB the next %d blocks\n", *eob_run);
637 break;
638
639 case 7:
640 debug_token("DCT_SHORT_ZRL_TOKEN, ");
641 /* note that this token actually indicates that (3 extra bits) + 1 0s
642 * should be output; this case specifies a run of (3 EBs) 0s and a
643 * coefficient of 0. */
644 *zero_run = get_bits(gb, 3);
645 *coeff = 0;
646 debug_token("skip the next %d positions in output matrix\n", *zero_run + 1);
647 break;
648
649 case 8:
650 debug_token("DCT_ZRL_TOKEN, ");
651 /* note that this token actually indicates that (6 extra bits) + 1 0s
652 * should be output; this case specifies a run of (6 EBs) 0s and a
653 * coefficient of 0. */
654 *zero_run = get_bits(gb, 6);
655 *coeff = 0;
656 debug_token("skip the next %d positions in output matrix\n", *zero_run + 1);
657 break;
658
659 case 9:
660 debug_token("ONE_TOKEN, output 1\n");
661 *coeff = 1;
662 break;
663
664 case 10:
665 debug_token("MINUS_ONE_TOKEN, output -1\n");
666 *coeff = -1;
667 break;
668
669 case 11:
670 debug_token("TWO_TOKEN, output 2\n");
671 *coeff = 2;
672 break;
673
674 case 12:
675 debug_token("MINUS_TWO_TOKEN, output -2\n");
676 *coeff = -2;
677 break;
678
679 case 13:
680 case 14:
681 case 15:
682 case 16:
683 debug_token("LOW_VAL_TOKENS, ");
684 if (get_bits(gb, 1))
685 *coeff = -(3 + (token - 13));
686 else
687 *coeff = 3 + (token - 13);
688 debug_token("output %d\n", *coeff);
689 break;
690
691 case 17:
692 debug_token("DCT_VAL_CATEGORY3, ");
693 sign = get_bits(gb, 1);
694 *coeff = 7 + get_bits(gb, 1);
695 if (sign)
696 *coeff = -(*coeff);
697 debug_token("output %d\n", *coeff);
698 break;
699
700 case 18:
701 debug_token("DCT_VAL_CATEGORY4, ");
702 sign = get_bits(gb, 1);
703 *coeff = 9 + get_bits(gb, 2);
704 if (sign)
705 *coeff = -(*coeff);
706 debug_token("output %d\n", *coeff);
707 break;
708
709 case 19:
710 debug_token("DCT_VAL_CATEGORY5, ");
711 sign = get_bits(gb, 1);
712 *coeff = 13 + get_bits(gb, 3);
713 if (sign)
714 *coeff = -(*coeff);
715 debug_token("output %d\n", *coeff);
716 break;
717
718 case 20:
719 debug_token("DCT_VAL_CATEGORY6, ");
720 sign = get_bits(gb, 1);
721 *coeff = 21 + get_bits(gb, 4);
722 if (sign)
723 *coeff = -(*coeff);
724 debug_token("output %d\n", *coeff);
725 break;
726
727 case 21:
728 debug_token("DCT_VAL_CATEGORY7, ");
729 sign = get_bits(gb, 1);
730 *coeff = 37 + get_bits(gb, 5);
731 if (sign)
732 *coeff = -(*coeff);
733 debug_token("output %d\n", *coeff);
734 break;
735
736 case 22:
737 debug_token("DCT_VAL_CATEGORY8, ");
738 sign = get_bits(gb, 1);
739 *coeff = 69 + get_bits(gb, 9);
740 if (sign)
741 *coeff = -(*coeff);
742 debug_token("output %d\n", *coeff);
743 break;
744
745 case 23:
746 case 24:
747 case 25:
748 case 26:
749 case 27:
750 debug_token("DCT_RUN_CATEGORY1, ");
751 *zero_run = token - 22;
752 if (get_bits(gb, 1))
753 *coeff = -1;
754 else
755 *coeff = 1;
756 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
757 break;
758
759 case 28:
760 debug_token("DCT_RUN_CATEGORY1B, ");
761 if (get_bits(gb, 1))
762 *coeff = -1;
763 else
764 *coeff = 1;
765 *zero_run = 6 + get_bits(gb, 2);
766 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
767 break;
768
769 case 29:
770 debug_token("DCT_RUN_CATEGORY1C, ");
771 if (get_bits(gb, 1))
772 *coeff = -1;
773 else
774 *coeff = 1;
775 *zero_run = 10 + get_bits(gb, 3);
776 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
777 break;
778
779 case 30:
780 debug_token("DCT_RUN_CATEGORY2, ");
781 sign = get_bits(gb, 1);
782 *coeff = 2 + get_bits(gb, 1);
783 if (sign)
784 *coeff = -(*coeff);
785 *zero_run = 1;
786 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
787 break;
788
789 case 31:
790 debug_token("DCT_RUN_CATEGORY2, ");
791 sign = get_bits(gb, 1);
792 *coeff = 2 + get_bits(gb, 1);
793 if (sign)
794 *coeff = -(*coeff);
795 *zero_run = 2 + get_bits(gb, 1);
796 debug_token("output %d 0s, then %d\n", *zero_run, *coeff);
797 break;
798
799 default:
800 printf (" vp3: help! Got a bad token: %d > 31\n", token);
801 break;
802
803 }
804 }
805
806 /*
807 * This function wipes out all of the fragment data.
808 */
809 static void init_frame(Vp3DecodeContext *s, GetBitContext *gb)
810 {
811 int i;
812
813 /* zero out all of the fragment information */
814 s->coded_fragment_list_index = 0;
815 for (i = 0; i < s->fragment_count; i++) {
816 memset(s->all_fragments[i].coeffs, 0, 64 * sizeof(DCTELEM));
817 s->all_fragments[i].coeff_count = 0;
818 s->all_fragments[i].last_coeff = 0;
819 }
820 }
821
822 /*
823 * This function sets of the dequantization tables used for a particular
824 * frame.
825 */
826 static void init_dequantizer(Vp3DecodeContext *s)
827 {
828
829 int quality_scale = vp31_quality_threshold[s->quality_index];
830 int dc_scale_factor = vp31_dc_scale_factor[s->quality_index];
831 int i, j;
832
833 debug_vp3(" vp3: initializing dequantization tables\n");
834
835 /*
836 * Scale dequantizers:
837 *
838 * quantizer * sf
839 * --------------
840 * 100
841 *
842 * where sf = dc_scale_factor for DC quantizer
843 * or quality_scale for AC quantizer
844 *
845 * Then, saturate the result to a lower limit of MIN_DEQUANT_VAL.
846 */
847 #define SCALER 1
848
849 /* scale DC quantizers */
850 s->intra_y_dequant[0] = vp31_intra_y_dequant[0] * dc_scale_factor / 100;
851 if (s->intra_y_dequant[0] < MIN_DEQUANT_VAL * 2)
852 s->intra_y_dequant[0] = MIN_DEQUANT_VAL * 2;
853 s->intra_y_dequant[0] *= SCALER;
854
855 s->intra_c_dequant[0] = vp31_intra_c_dequant[0] * dc_scale_factor / 100;
856 if (s->intra_c_dequant[0] < MIN_DEQUANT_VAL * 2)
857 s->intra_c_dequant[0] = MIN_DEQUANT_VAL * 2;
858 s->intra_c_dequant[0] *= SCALER;
859
860 s->inter_dequant[0] = vp31_inter_dequant[0] * dc_scale_factor / 100;
861 if (s->inter_dequant[0] < MIN_DEQUANT_VAL * 4)
862 s->inter_dequant[0] = MIN_DEQUANT_VAL * 4;
863 s->inter_dequant[0] *= SCALER;
864
865 /* scale AC quantizers, zigzag at the same time in preparation for
866 * the dequantization phase */
867 for (i = 1; i < 64; i++) {
868
869 j = zigzag_index[i];
870
871 s->intra_y_dequant[j] = vp31_intra_y_dequant[i] * quality_scale / 100;
872 if (s->intra_y_dequant[j] < MIN_DEQUANT_VAL)
873 s->intra_y_dequant[j] = MIN_DEQUANT_VAL;
874 s->intra_y_dequant[j] *= SCALER;
875
876 s->intra_c_dequant[j] = vp31_intra_c_dequant[i] * quality_scale / 100;
877 if (s->intra_c_dequant[j] < MIN_DEQUANT_VAL)
878 s->intra_c_dequant[j] = MIN_DEQUANT_VAL;
879 s->intra_c_dequant[j] *= SCALER;
880
881 s->inter_dequant[j] = vp31_inter_dequant[i] * quality_scale / 100;
882 if (s->inter_dequant[j] < MIN_DEQUANT_VAL * 2)
883 s->inter_dequant[j] = MIN_DEQUANT_VAL * 2;
884 s->inter_dequant[j] *= SCALER;
885 }
886
887 /* print debug information as requested */
888 debug_dequantizers("intra Y dequantizers:\n");
889 for (i = 0; i < 8; i++) {
890 for (j = i * 8; j < i * 8 + 8; j++) {
891 debug_dequantizers(" %4d,", s->intra_y_dequant[j]);
892 }
893 debug_dequantizers("\n");
894 }
895 debug_dequantizers("\n");
896
897 debug_dequantizers("intra C dequantizers:\n");
898 for (i = 0; i < 8; i++) {
899 for (j = i * 8; j < i * 8 + 8; j++) {
900 debug_dequantizers(" %4d,", s->intra_c_dequant[j]);
901 }
902 debug_dequantizers("\n");
903 }
904 debug_dequantizers("\n");
905
906 debug_dequantizers("interframe dequantizers:\n");
907 for (i = 0; i < 8; i++) {
908 for (j = i * 8; j < i * 8 + 8; j++) {
909 debug_dequantizers(" %4d,", s->inter_dequant[j]);
910 }
911 debug_dequantizers("\n");
912 }
913 debug_dequantizers("\n");
914 }
915
916 /*
917 * This function is used to fetch runs of 1s or 0s from the bitstream for
918 * use in determining which superblocks are fully and partially coded.
919 *
920 * Codeword RunLength
921 * 0 1
922 * 10x 2-3
923 * 110x 4-5
924 * 1110xx 6-9
925 * 11110xxx 10-17
926 * 111110xxxx 18-33
927 * 111111xxxxxxxxxxxx 34-4129
928 */
929 static int get_superblock_run_length(GetBitContext *gb)
930 {
931
932 if (get_bits(gb, 1) == 0)
933 return 1;
934
935 else if (get_bits(gb, 1) == 0)
936 return (2 + get_bits(gb, 1));
937
938 else if (get_bits(gb, 1) == 0)
939 return (4 + get_bits(gb, 1));
940
941 else if (get_bits(gb, 1) == 0)
942 return (6 + get_bits(gb, 2));
943
944 else if (get_bits(gb, 1) == 0)
945 return (10 + get_bits(gb, 3));
946
947 else if (get_bits(gb, 1) == 0)
948 return (18 + get_bits(gb, 4));
949
950 else
951 return (34 + get_bits(gb, 12));
952
953 }
954
955 /*
956 * This function is used to fetch runs of 1s or 0s from the bitstream for
957 * use in determining which particular fragments are coded.
958 *
959 * Codeword RunLength
960 * 0x 1-2
961 * 10x 3-4
962 * 110x 5-6
963 * 1110xx 7-10
964 * 11110xx 11-14
965 * 11111xxxx 15-30
966 */
967 static int get_fragment_run_length(GetBitContext *gb)
968 {
969
970 if (get_bits(gb, 1) == 0)
971 return (1 + get_bits(gb, 1));
972
973 else if (get_bits(gb, 1) == 0)
974 return (3 + get_bits(gb, 1));
975
976 else if (get_bits(gb, 1) == 0)
977 return (5 + get_bits(gb, 1));
978
979 else if (get_bits(gb, 1) == 0)
980 return (7 + get_bits(gb, 2));
981
982 else if (get_bits(gb, 1) == 0)
983 return (11 + get_bits(gb, 2));
984
985 else
986 return (15 + get_bits(gb, 4));
987
988 }
989
990 /*
991 * This function decodes a VLC from the bitstream and returns a number
992 * that ranges from 0..7. The number indicates which of the 8 coding
993 * modes to use.
994 *
995 * VLC Number
996 * 0 0
997 * 10 1
998 * 110 2
999 * 1110 3
1000 * 11110 4
1001 * 111110 5
1002 * 1111110 6
1003 * 1111111 7
1004 *
1005 */
1006 static int get_mode_code(GetBitContext *gb)
1007 {
1008
1009 if (get_bits(gb, 1) == 0)
1010 return 0;
1011
1012 else if (get_bits(gb, 1) == 0)
1013 return 1;
1014
1015 else if (get_bits(gb, 1) == 0)
1016 return 2;
1017
1018 else if (get_bits(gb, 1) == 0)
1019 return 3;
1020
1021 else if (get_bits(gb, 1) == 0)
1022 return 4;
1023
1024 else if (get_bits(gb, 1) == 0)
1025 return 5;
1026
1027 else if (get_bits(gb, 1) == 0)
1028 return 6;
1029
1030 else
1031 return 7;
1032
1033 }
1034
1035 /*
1036 * This function extracts a motion vector from the bitstream using a VLC
1037 * scheme. 3 bits are fetched from the bitstream and 1 of 8 actions is
1038 * taken depending on the value on those 3 bits:
1039 *
1040 * 0: return 0
1041 * 1: return 1
1042 * 2: return -1
1043 * 3: if (next bit is 1) return -2, else return 2
1044 * 4: if (next bit is 1) return -3, else return 3
1045 * 5: return 4 + (next 2 bits), next bit is sign
1046 * 6: return 8 + (next 3 bits), next bit is sign
1047 * 7: return 16 + (next 4 bits), next bit is sign
1048 */
1049 static int get_motion_vector_vlc(GetBitContext *gb)
1050 {
1051 int bits;
1052
1053 bits = get_bits(gb, 3);
1054
1055 switch(bits) {
1056
1057 case 0:
1058 bits = 0;
1059 break;
1060
1061 case 1:
1062 bits = 1;
1063 break;
1064
1065 case 2:
1066 bits = -1;
1067 break;
1068
1069 case 3:
1070 if (get_bits(gb, 1) == 0)
1071 bits = 2;
1072 else
1073 bits = -2;
1074 break;
1075
1076 case 4:
1077 if (get_bits(gb, 1) == 0)
1078 bits = 3;
1079 else
1080 bits = -3;
1081 break;
1082
1083 case 5:
1084 bits = 4 + get_bits(gb, 2);
1085 if (get_bits(gb, 1) == 1)
1086 bits = -bits;
1087 break;
1088
1089 case 6:
1090 bits = 8 + get_bits(gb, 3);
1091 if (get_bits(gb, 1) == 1)
1092 bits = -bits;
1093 break;
1094
1095 case 7:
1096 bits = 16 + get_bits(gb, 4);
1097 if (get_bits(gb, 1) == 1)
1098 bits = -bits;
1099 break;
1100
1101 }
1102
1103 return bits;
1104 }
1105
1106 /*
1107 * This function fetches a 5-bit number from the stream followed by
1108 * a sign and calls it a motion vector.
1109 */
1110 static int get_motion_vector_fixed(GetBitContext *gb)
1111 {
1112
1113 int bits;
1114
1115 bits = get_bits(gb, 5);
1116
1117 if (get_bits(gb, 1) == 1)
1118 bits = -bits;
1119
1120 return bits;
1121 }
1122
1123 /*
1124 * This function unpacks all of the superblock/macroblock/fragment coding
1125 * information from the bitstream.
1126 */
1127 static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
1128 {
1129 int bit = 0;
1130 int current_superblock = 0;
1131 int current_run = 0;
1132 int decode_fully_flags = 0;
1133 int decode_partial_blocks = 0;
1134 int first_c_fragment_seen;
1135
1136 int i, j;
1137 int current_fragment;
1138
1139 debug_vp3(" vp3: unpacking superblock coding\n");
1140
1141 if (s->keyframe) {
1142
1143 debug_vp3(" keyframe-- all superblocks are fully coded\n");
1144 memset(s->superblock_coding, SB_FULLY_CODED, s->superblock_count);
1145
1146 } else {
1147
1148 /* unpack the list of partially-coded superblocks */
1149 bit = get_bits(gb, 1);
1150 /* toggle the bit because as soon as the first run length is
1151 * fetched the bit will be toggled again */
1152 bit ^= 1;
1153 while (current_superblock < s->superblock_count) {
1154 if (current_run == 0) {
1155 bit ^= 1;
1156 current_run = get_superblock_run_length(gb);
1157 debug_block_coding(" setting superblocks %d..%d to %s\n",
1158 current_superblock,
1159 current_superblock + current_run - 1,
1160 (bit) ? "partially coded" : "not coded");
1161
1162 /* if any of the superblocks are not partially coded, flag
1163 * a boolean to decode the list of fully-coded superblocks */
1164 if (bit == 0)
1165 decode_fully_flags = 1;
1166 } else {
1167
1168 /* make a note of the fact that there are partially coded
1169 * superblocks */
1170 decode_partial_blocks = 1;
1171
1172 }
1173 s->superblock_coding[current_superblock++] =
1174 (bit) ? SB_PARTIALLY_CODED : SB_NOT_CODED;
1175 current_run--;
1176 }
1177
1178 /* unpack the list of fully coded superblocks if any of the blocks were
1179 * not marked as partially coded in the previous step */
1180 if (decode_fully_flags) {
1181
1182 current_superblock = 0;
1183 current_run = 0;
1184 bit = get_bits(gb, 1);
1185 /* toggle the bit because as soon as the first run length is
1186 * fetched the bit will be toggled again */
1187 bit ^= 1;
1188 while (current_superblock < s->superblock_count) {
1189
1190 /* skip any superblocks already marked as partially coded */
1191 if (s->superblock_coding[current_superblock] == SB_NOT_CODED) {
1192
1193 if (current_run == 0) {
1194 bit ^= 1;
1195 current_run = get_superblock_run_length(gb);
1196 }
1197
1198 debug_block_coding(" setting superblock %d to %s\n",
1199 current_superblock,
1200 (bit) ? "fully coded" : "not coded");
1201 s->superblock_coding[current_superblock] =
1202 (bit) ? SB_FULLY_CODED : SB_NOT_CODED;
1203 current_run--;
1204 }
1205 current_superblock++;
1206 }
1207 }
1208
1209 /* if there were partial blocks, initialize bitstream for
1210 * unpacking fragment codings */
1211 if (decode_partial_blocks) {
1212
1213 current_run = 0;
1214 bit = get_bits(gb, 1);
1215 /* toggle the bit because as soon as the first run length is
1216 * fetched the bit will be toggled again */
1217 bit ^= 1;
1218 }
1219 }
1220
1221 /* figure out which fragments are coded; iterate through each
1222 * superblock (all planes) */
1223 s->coded_fragment_list_index = 0;
1224 s->first_coded_y_fragment = s->first_coded_c_fragment = 0;
1225 s->last_coded_y_fragment = s->last_coded_c_fragment = -1;
1226 first_c_fragment_seen = 0;
1227 memset(s->macroblock_coding, MODE_COPY, s->macroblock_count);
1228 for (i = 0; i < s->superblock_count; i++) {
1229
1230 /* iterate through all 16 fragments in a superblock */
1231 for (j = 0; j < 16; j++) {
1232
1233 /* if the fragment is in bounds, check its coding status */
1234 current_fragment = s->superblock_fragments[i * 16 + j];
1235 if (current_fragment >= s->fragment_count) {
1236 printf (" vp3:unpack_superblocks(): bad fragment number (%d >= %d)\n",
1237 current_fragment, s->fragment_count);
1238 return 1;
1239 }
1240 if (current_fragment != -1) {
1241 if (s->superblock_coding[i] == SB_NOT_CODED) {
1242
1243 /* copy all the fragments from the prior frame */
1244 s->all_fragments[current_fragment].coding_method =
1245 MODE_COPY;
1246
1247 } else if (s->superblock_coding[i] == SB_PARTIALLY_CODED) {
1248
1249 /* fragment may or may not be coded; this is the case
1250 * that cares about the fragment coding runs */
1251 if (current_run == 0) {
1252 bit ^= 1;
1253 current_run = get_fragment_run_length(gb);
1254 }
1255
1256 if (bit) {
1257 /* default mode; actual mode will be decoded in
1258 * the next phase */
1259 s->all_fragments[current_fragment].coding_method =
1260 MODE_INTER_NO_MV;
1261 s->coded_fragment_list[s->coded_fragment_list_index] =
1262 current_fragment;
1263 if ((current_fragment >= s->u_fragment_start) &&
1264 (s->last_coded_y_fragment == -1) &&
1265 (!first_c_fragment_seen)) {
1266 s->first_coded_c_fragment = s->coded_fragment_list_index;
1267 s->last_coded_y_fragment = s->first_coded_c_fragment - 1;
1268 first_c_fragment_seen = 1;
1269 }
1270 s->coded_fragment_list_index++;
1271 s->macroblock_coding[s->all_fragments[current_fragment].macroblock] = MODE_INTER_NO_MV;
1272 debug_block_coding(" superblock %d is partially coded, fragment %d is coded\n",
1273 i, current_fragment);
1274 } else {
1275 /* not coded; copy this fragment from the prior frame */
1276 s->all_fragments[current_fragment].coding_method =
1277 MODE_COPY;
1278 debug_block_coding(" superblock %d is partially coded, fragment %d is not coded\n",
1279 i, current_fragment);
1280 }
1281
1282 current_run--;
1283
1284 } else {
1285
1286 /* fragments are fully coded in this superblock; actual
1287 * coding will be determined in next step */
1288 s->all_fragments[current_fragment].coding_method =
1289 MODE_INTER_NO_MV;
1290 s->coded_fragment_list[s->coded_fragment_list_index] =
1291 current_fragment;
1292 if ((current_fragment >= s->u_fragment_start) &&
1293 (s->last_coded_y_fragment == -1) &&
1294 (!first_c_fragment_seen)) {
1295 s->first_coded_c_fragment = s->coded_fragment_list_index;
1296 s->last_coded_y_fragment = s->first_coded_c_fragment - 1;
1297 first_c_fragment_seen = 1;
1298 }
1299 s->coded_fragment_list_index++;
1300 s->macroblock_coding[s->all_fragments[current_fragment].macroblock] = MODE_INTER_NO_MV;
1301 debug_block_coding(" superblock %d is fully coded, fragment %d is coded\n",
1302 i, current_fragment);
1303 }
1304 }
1305 }
1306 }
1307
1308 if (!first_c_fragment_seen)
1309 /* only Y fragments coded in this frame */
1310 s->last_coded_y_fragment = s->coded_fragment_list_index - 1;
1311 else
1312 /* end the list of coded fragments */
1313 s->last_coded_c_fragment = s->coded_fragment_list_index - 1;
1314
1315 debug_block_coding(" %d total coded fragments, y: %d -> %d, c: %d -> %d\n",
1316 s->coded_fragment_list_index,
1317 s->first_coded_y_fragment,
1318 s->last_coded_y_fragment,
1319 s->first_coded_c_fragment,
1320 s->last_coded_c_fragment);
1321
1322 return 0;
1323 }
1324
1325 /*
1326 * This function unpacks all the coding mode data for individual macroblocks
1327 * from the bitstream.
1328 */
1329 static int unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
1330 {
1331 int i, j, k;
1332 int scheme;
1333 int current_macroblock;
1334 int current_fragment;
1335 int coding_mode;
1336
1337 debug_vp3(" vp3: unpacking encoding modes\n");
1338
1339 if (s->keyframe) {
1340 debug_vp3(" keyframe-- all blocks are coded as INTRA\n");
1341
1342 for (i = 0; i < s->fragment_count; i++)
1343 s->all_fragments[i].coding_method = MODE_INTRA;
1344
1345 } else {
1346
1347 /* fetch the mode coding scheme for this frame */
1348 scheme = get_bits(gb, 3);
1349 debug_modes(" using mode alphabet %d\n", scheme);
1350
1351 /* is it a custom coding scheme? */
1352 if (scheme == 0) {
1353 debug_modes(" custom mode alphabet ahead:\n");
1354 for (i = 0; i < 8; i++)
1355 ModeAlphabet[scheme][get_bits(gb, 3)] = i;
1356 }
1357
1358 for (i = 0; i < 8; i++)
1359 debug_modes(" mode[%d][%d] = %d\n", scheme, i,
1360 ModeAlphabet[scheme][i]);
1361
1362 /* iterate through all of the macroblocks that contain 1 or more
1363 * coded fragments */
1364 for (i = 0; i < s->u_superblock_start; i++) {
1365
1366 for (j = 0; j < 4; j++) {
1367 current_macroblock = s->superblock_macroblocks[i * 4 + j];
1368 if ((current_macroblock == -1) ||
1369 (s->macroblock_coding[current_macroblock] == MODE_COPY))
1370 continue;
1371 if (current_macroblock >= s->macroblock_count) {
1372 printf (" vp3:unpack_modes(): bad macroblock number (%d >= %d)\n",
1373 current_macroblock, s->macroblock_count);
1374 return 1;
1375 }
1376
1377 /* mode 7 means get 3 bits for each coding mode */
1378 if (scheme == 7)
1379 coding_mode = get_bits(gb, 3);
1380 else
1381 coding_mode = ModeAlphabet[scheme][get_mode_code(gb)];
1382
1383 s->macroblock_coding[current_macroblock] = coding_mode;
1384 for (k = 0; k < 6; k++) {
1385 current_fragment =
1386 s->macroblock_fragments[current_macroblock * 6 + k];
1387 if (current_fragment == -1)
1388 continue;
1389 if (current_fragment >= s->fragment_count) {
1390 printf (" vp3:unpack_modes(): bad fragment number (%d >= %d)\n",
1391 current_fragment, s->fragment_count);
1392 return 1;
1393 }
1394 if (s->all_fragments[current_fragment].coding_method !=
1395 MODE_COPY)
1396 s->all_fragments[current_fragment].coding_method =
1397 coding_mode;
1398 }
1399
1400 debug_modes(" coding method for macroblock starting @ fragment %d = %d\n",
1401 s->macroblock_fragments[current_macroblock * 6], coding_mode);
1402 }
1403 }
1404 }
1405
1406 return 0;
1407 }
1408
1409 /*
1410 * This function adjusts the components of a motion vector for the halfpel
1411 * motion grid. c_plane indicates whether the vector applies to the U or V
1412 * plane. The function returns the halfpel function index to be used in
1413 * ffmpeg's put_pixels[]() array of functions.
1414 */
1415 static inline int adjust_vector(int *x, int *y, int c_plane)
1416 {
1417 int motion_halfpel_index = 0;
1418 int x_halfpel;
1419 int y_halfpel;
1420
1421 if (!c_plane) {
1422
1423 x_halfpel = *x & 1;
1424 motion_halfpel_index |= x_halfpel;
1425 if (*x >= 0)
1426 *x >>= 1;
1427 else
1428 *x = -( (-(*x) >> 1) + x_halfpel);
1429
1430 y_halfpel = *y & 1;
1431 motion_halfpel_index |= (y_halfpel << 1);
1432 if (*y >= 0)
1433 *y >>= 1;
1434 else
1435 *y = -( (-(*y) >> 1) + y_halfpel);
1436
1437 } else {
1438
1439 x_halfpel = ((*x & 0x03) != 0);
1440 motion_halfpel_index |= x_halfpel;
1441 if (*x >= 0)
1442 *x >>= 2;
1443 else
1444 *x = -( (-(*x) >> 2) + x_halfpel);
1445
1446 y_halfpel = ((*y & 0x03) != 0);
1447 motion_halfpel_index |= (y_halfpel << 1);
1448 if (*y >= 0)
1449 *y >>= 2;
1450 else
1451 *y = -( (-(*y) >> 2) + y_halfpel);
1452
1453 }
1454
1455 return motion_halfpel_index;
1456 }
1457
1458 /*
1459 * This function unpacks all the motion vectors for the individual
1460 * macroblocks from the bitstream.
1461 */
1462 static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
1463 {
1464 int i, j, k;
1465 int coding_mode;
1466 int motion_x[6];
1467 int motion_y[6];
1468 int last_motion_x = 0;
1469 int last_motion_y = 0;
1470 int prior_last_motion_x = 0;
1471 int prior_last_motion_y = 0;
1472 int current_macroblock;
1473 int current_fragment;
1474
1475 debug_vp3(" vp3: unpacking motion vectors\n");
1476
1477 if (s->keyframe) {
1478
1479 debug_vp3(" keyframe-- there are no motion vectors\n");
1480
1481 } else {
1482
1483 memset(motion_x, 0, 6 * sizeof(int));
1484 memset(motion_y, 0, 6 * sizeof(int));
1485
1486 /* coding mode 0 is the VLC scheme; 1 is the fixed code scheme */
1487 coding_mode = get_bits(gb, 1);
1488 debug_vectors(" using %s scheme for unpacking motion vectors\n",
1489 (coding_mode == 0) ? "VLC" : "fixed-length");
1490
1491 /* iterate through all of the macroblocks that contain 1 or more
1492 * coded fragments */
1493 for (i = 0; i < s->u_superblock_start; i++) {
1494
1495 for (j = 0; j < 4; j++) {
1496 current_macroblock = s->superblock_macroblocks[i * 4 + j];
1497 if ((current_macroblock == -1) ||
1498 (s->macroblock_coding[current_macroblock] == MODE_COPY))
1499 continue;
1500 if (current_macroblock >= s->macroblock_count) {
1501 printf (" vp3:unpack_vectors(): bad macroblock number (%d >= %d)\n",
1502 current_macroblock, s->macroblock_count);
1503 return 1;
1504 }
1505
1506 current_fragment = s->macroblock_fragments[current_macroblock * 6];
1507 if (current_fragment >= s->fragment_count) {
1508 printf (" vp3:unpack_vectors(): bad fragment number (%d >= %d\n",
1509 current_fragment, s->fragment_count);
1510 return 1;
1511 }
1512 switch (s->macroblock_coding[current_macroblock]) {
1513
1514 case MODE_INTER_PLUS_MV:
1515 case MODE_GOLDEN_MV:
1516 /* all 6 fragments use the same motion vector */
1517 if (coding_mode == 0) {
1518 motion_x[0] = get_motion_vector_vlc(gb);
1519 motion_y[0] = get_motion_vector_vlc(gb);
1520 } else {
1521 motion_x[0] = get_motion_vector_fixed(gb);
1522 motion_y[0] = get_motion_vector_fixed(gb);
1523 }
1524 for (k = 1; k < 6; k++) {
1525 motion_x[k] = motion_x[0];
1526 motion_y[k] = motion_y[0];
1527 }
1528
1529 /* vector maintenance, only on MODE_INTER_PLUS_MV */
1530 if (s->all_fragments[current_fragment].coding_method ==
1531 MODE_INTER_PLUS_MV) {
1532 prior_last_motion_x = last_motion_x;
1533 prior_last_motion_y = last_motion_y;
1534 last_motion_x = motion_x[0];
1535 last_motion_y = motion_y[0];
1536 }
1537 break;
1538
1539 case MODE_INTER_FOURMV:
1540 /* fetch 4 vectors from the bitstream, one for each
1541 * Y fragment, then average for the C fragment vectors */
1542 motion_x[4] = motion_y[4] = 0;
1543 for (k = 0; k < 4; k++) {
1544 if (coding_mode == 0) {
1545 motion_x[k] = get_motion_vector_vlc(gb);
1546 motion_y[k] = get_motion_vector_vlc(gb);
1547 } else {
1548 motion_x[k] = get_motion_vector_fixed(gb);
1549 motion_y[k] = get_motion_vector_fixed(gb);
1550 }
1551 motion_x[4] += motion_x[k];
1552 motion_y[4] += motion_y[k];
1553 }
1554
1555 if (motion_x[4] >= 0)
1556 motion_x[4] = (motion_x[4] + 2) / 4;
1557 else
1558 motion_x[4] = (motion_x[4] - 2) / 4;
1559 motion_x[5] = motion_x[4];
1560
1561 if (motion_y[4] >= 0)
1562 motion_y[4] = (motion_y[4] + 2) / 4;
1563 else
1564 motion_y[4] = (motion_y[4] - 2) / 4;
1565 motion_y[5] = motion_y[4];
1566
1567 /* vector maintenance; vector[3] is treated as the
1568 * last vector in this case */
1569 prior_last_motion_x = last_motion_x;
1570 prior_last_motion_y = last_motion_y;
1571 last_motion_x = motion_x[3];
1572 last_motion_y = motion_y[3];
1573 break;
1574
1575 case MODE_INTER_LAST_MV:
1576 /* all 6 fragments use the last motion vector */
1577 motion_x[0] = last_motion_x;
1578 motion_y[0] = last_motion_y;
1579 for (k = 1; k < 6; k++) {
1580 motion_x[k] = motion_x[0];
1581 motion_y[k] = motion_y[0];
1582 }
1583
1584 /* no vector maintenance (last vector remains the
1585 * last vector) */
1586 break;
1587
1588 case MODE_INTER_PRIOR_LAST:
1589 /* all 6 fragments use the motion vector prior to the
1590 * last motion vector */
1591 motion_x[0] = prior_last_motion_x;
1592 motion_y[0] = prior_last_motion_y;
1593 for (k = 1; k < 6; k++) {
1594 motion_x[k] = motion_x[0];
1595 motion_y[k] = motion_y[0];
1596 }
1597
1598 /* vector maintenance */
1599 prior_last_motion_x = last_motion_x;
1600 prior_last_motion_y = last_motion_y;
1601 last_motion_x = motion_x[0];
1602 last_motion_y = motion_y[0];
1603 break;
1604
1605 default:
1606 /* covers intra, inter without MV, golden without MV */
1607 memset(motion_x, 0, 6 * sizeof(int));
1608 memset(motion_y, 0, 6 * sizeof(int));
1609
1610 /* no vector maintenance */
1611 break;
1612 }
1613
1614 /* assign the motion vectors to the correct fragments */
1615 debug_vectors(" vectors for macroblock starting @ fragment %d (coding method %d):\n",
1616 current_fragment,
1617 s->all_fragments[current_fragment].coding_method);
1618 for (k = 0; k < 6; k++) {
1619 current_fragment =
1620 s->macroblock_fragments[current_macroblock * 6 + k];
1621 if (current_fragment == -1)
1622 continue;
1623 if (current_fragment >= s->fragment_count) {
1624 printf (" vp3:unpack_vectors(): bad fragment number (%d >= %d)\n",
1625 current_fragment, s->fragment_count);
1626 return 1;
1627 }
1628 s->all_fragments[current_fragment].motion_halfpel_index =
1629 adjust_vector(&motion_x[k], &motion_y[k],
1630 ((k == 4) || (k == 5)));
1631 s->all_fragments[current_fragment].motion_x = motion_x[k];
1632 s->all_fragments[current_fragment].motion_y = motion_y[k];
1633 debug_vectors(" vector %d: fragment %d = (%d, %d), index %d\n",
1634 k, current_fragment, motion_x[k], motion_y[k],
1635 s->all_fragments[current_fragment].motion_halfpel_index);
1636 }
1637 }
1638 }
1639 }
1640
1641 return 0;
1642 }
1643
1644 /*
1645 * This function is called by unpack_dct_coeffs() to extract the VLCs from
1646 * the bitstream. The VLCs encode tokens which are used to unpack DCT
1647 * data. This function unpacks all the VLCs for either the Y plane or both
1648 * C planes, and is called for DC coefficients or different AC coefficient
1649 * levels (since different coefficient types require different VLC tables.
1650 *
1651 * This function returns a residual eob run. E.g, if a particular token gave
1652 * instructions to EOB the next 5 fragments and there were only 2 fragments
1653 * left in the current fragment range, 3 would be returned so that it could
1654 * be passed into the next call to this same function.
1655 */
1656 static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
1657 VLC *table, int coeff_index,
1658 int first_fragment, int last_fragment,
1659 int eob_run)
1660 {
1661 int i;
1662 int token;
1663 int zero_run;
1664 DCTELEM coeff;
1665 Vp3Fragment *fragment;
1666
1667 if ((first_fragment >= s->fragment_count) ||
1668 (last_fragment >= s->fragment_count)) {
1669
1670 printf (" vp3:unpack_vlcs(): bad fragment number (%d -> %d ?)\n",
1671 first_fragment, last_fragment);
1672 return 0;
1673 }
1674
1675 for (i = first_fragment; i <= last_fragment; i++) {
1676
1677 fragment = &s->all_fragments[s->coded_fragment_list[i]];
1678 if (fragment->coeff_count > coeff_index)
1679 continue;
1680
1681 if (!eob_run) {
1682 /* decode a VLC into a token */
1683 token = get_vlc2(gb, table->table, 5, 3);
1684 debug_vlc(" token = %2d, ", token);
1685 /* use the token to get a zero run, a coefficient, and an eob run */
1686 unpack_token(gb, token, &zero_run, &coeff, &eob_run);
1687 }
1688
1689 if (!eob_run) {
1690 fragment->coeff_count += zero_run;
1691 if (fragment->coeff_count < 64)
1692 fragment->coeffs[fragment->coeff_count++] = coeff;
1693 debug_vlc(" fragment %d coeff = %d\n",
1694 s->coded_fragment_list[i], fragment->coeffs[coeff_index]);
1695 } else {
1696 fragment->last_coeff = fragment->coeff_count;
1697 fragment->coeff_count = 64;
1698 debug_vlc(" fragment %d eob with %d coefficients\n",
1699 s->coded_fragment_list[i], fragment->last_coeff);
1700 eob_run--;
1701 }
1702 }
1703
1704 return eob_run;
1705 }
1706
1707 /*
1708 * This function unpacks all of the DCT coefficient data from the
1709 * bitstream.
1710 */
1711 static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
1712 {
1713 int i;
1714 int dc_y_table;
1715 int dc_c_table;
1716 int ac_y_table;
1717 int ac_c_table;
1718 int residual_eob_run = 0;
1719
1720 /* fetch the DC table indices */
1721 dc_y_table = get_bits(gb, 4);
1722 dc_c_table = get_bits(gb, 4);
1723
1724 /* unpack the Y plane DC coefficients */
1725 debug_vp3(" vp3: unpacking Y plane DC coefficients using table %d\n",
1726 dc_y_table);
1727 residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_y_table], 0,
1728 s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1729
1730 /* unpack the C plane DC coefficients */
1731 debug_vp3(" vp3: unpacking C plane DC coefficients using table %d\n",
1732 dc_c_table);
1733 residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
1734 s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
1735
1736 /* fetch the AC table indices */
1737 ac_y_table = get_bits(gb, 4);
1738 ac_c_table = get_bits(gb, 4);
1739
1740 /* unpack the group 1 AC coefficients (coeffs 1-5) */
1741 for (i = 1; i <= 5; i++) {
1742
1743 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1744 i, ac_y_table);
1745 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_y_table], i,
1746 s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1747
1748 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1749 i, ac_c_table);
1750 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_1[ac_c_table], i,
1751 s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
1752 }
1753
1754 /* unpack the group 2 AC coefficients (coeffs 6-14) */
1755 for (i = 6; i <= 14; i++) {
1756
1757 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1758 i, ac_y_table);
1759 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_y_table], i,
1760 s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1761
1762 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1763 i, ac_c_table);
1764 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_2[ac_c_table], i,
1765 s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
1766 }
1767
1768 /* unpack the group 3 AC coefficients (coeffs 15-27) */
1769 for (i = 15; i <= 27; i++) {
1770
1771 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1772 i, ac_y_table);
1773 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_y_table], i,
1774 s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1775
1776 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1777 i, ac_c_table);
1778 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_3[ac_c_table], i,
1779 s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
1780 }
1781
1782 /* unpack the group 4 AC coefficients (coeffs 28-63) */
1783 for (i = 28; i <= 63; i++) {
1784
1785 debug_vp3(" vp3: unpacking level %d Y plane AC coefficients using table %d\n",
1786 i, ac_y_table);
1787 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_y_table], i,
1788 s->first_coded_y_fragment, s->last_coded_y_fragment, residual_eob_run);
1789
1790 debug_vp3(" vp3: unpacking level %d C plane AC coefficients using table %d\n",
1791 i, ac_c_table);
1792 residual_eob_run = unpack_vlcs(s, gb, &s->ac_vlc_4[ac_c_table], i,
1793 s->first_coded_c_fragment, s->last_coded_c_fragment, residual_eob_run);
1794 }
1795
1796 return 0;
1797 }
1798
1799 /*
1800 * This function reverses the DC prediction for each coded fragment in
1801 * the frame. Much of this function is adapted directly from the original
1802 * VP3 source code.
1803 */
1804 #define COMPATIBLE_FRAME(x) \
1805 (compatible_frame[s->all_fragments[x].coding_method] == current_frame_type)
1806 #define FRAME_CODED(x) (s->all_fragments[x].coding_method != MODE_COPY)
1807 static inline int iabs (int x) { return ((x < 0) ? -x : x); }
1808
1809 static void reverse_dc_prediction(Vp3DecodeContext *s,
1810 int first_fragment,
1811 int fragment_width,
1812 int fragment_height)
1813 {
1814
1815 #define PUL 8
1816 #define PU 4
1817 #define PUR 2
1818 #define PL 1
1819
1820 int x, y;
1821 int i = first_fragment;
1822
1823 /*
1824 * Fragment prediction groups:
1825 *
1826 * 32222222226
1827 * 10000000004
1828 * 10000000004
1829 * 10000000004
1830 * 10000000004
1831 *
1832 * Note: Groups 5 and 7 do not exist as it would mean that the
1833 * fragment's x coordinate is both 0 and (width - 1) at the same time.
1834 */
1835 int predictor_group;
1836 short predicted_dc;
1837
1838 /* validity flags for the left, up-left, up, and up-right fragments */
1839 int fl, ful, fu, fur;
1840
1841 /* DC values for the left, up-left, up, and up-right fragments */
1842 int vl, vul, vu, vur;
1843
1844 /* indices for the left, up-left, up, and up-right fragments */
1845 int l, ul, u, ur;
1846
1847 /*
1848 * The 6 fields mean:
1849 * 0: up-left multiplier
1850 * 1: up multiplier
1851 * 2: up-right multiplier
1852 * 3: left multiplier
1853 * 4: mask
1854 * 5: right bit shift divisor (e.g., 7 means >>=7, a.k.a. div by 128)
1855 */
1856 int predictor_transform[16][6] = {
1857 { 0, 0, 0, 0, 0, 0 },
1858 { 0, 0, 0, 1, 0, 0 }, // PL
1859 { 0, 0, 1, 0, 0, 0 }, // PUR
1860 { 0, 0, 53, 75, 127, 7 }, // PUR|PL
1861 { 0, 1, 0, 0, 0, 0 }, // PU
1862 { 0, 1, 0, 1, 1, 1 }, // PU|PL
1863 { 0, 1, 0, 0, 0, 0 }, // PU|PUR
1864 { 0, 0, 53, 75, 127, 7 }, // PU|PUR|PL
1865 { 1, 0, 0, 0, 0, 0 }, // PUL
1866 { 0, 0, 0, 1, 0, 0 }, // PUL|PL
1867 { 1, 0, 1, 0, 1, 1 }, // PUL|PUR
1868 { 0, 0, 53, 75, 127, 7 }, // PUL|PUR|PL
1869 { 0, 1, 0, 0, 0, 0 }, // PUL|PU
1870 {-26, 29, 0, 29, 31, 5 }, // PUL|PU|PL
1871 { 3, 10, 3, 0, 15, 4 }, // PUL|PU|PUR
1872 {-26, 29, 0, 29, 31, 5 } // PUL|PU|PUR|PL
1873 };
1874
1875 /* This table shows which types of blocks can use other blocks for
1876 * prediction. For example, INTRA is the only mode in this table to
1877 * have a frame number of 0. That means INTRA blocks can only predict
1878 * from other INTRA blocks. There are 2 golden frame coding types;
1879 * blocks encoding in these modes can only predict from other blocks
1880 * that were encoded with these 1 of these 2 modes. */
1881 unsigned char compatible_frame[8] = {
1882 1, /* MODE_INTER_NO_MV */
1883 0, /* MODE_INTRA */
1884 1, /* MODE_INTER_PLUS_MV */
1885 1, /* MODE_INTER_LAST_MV */
1886 1, /* MODE_INTER_PRIOR_MV */
1887 2, /* MODE_USING_GOLDEN */
1888 2, /* MODE_GOLDEN_MV */
1889 1 /* MODE_INTER_FOUR_MV */
1890 };
1891 int current_frame_type;
1892
1893 /* there is a last DC predictor for each of the 3 frame types */
1894 short last_dc[3];
1895
1896 int transform = 0;
1897
1898 debug_vp3(" vp3: reversing DC prediction\n");
1899
1900 vul = vu = vur = vl = 0;
1901 last_dc[0] = last_dc[1] = last_dc[2] = 0;
1902
1903 /* for each fragment row... */
1904 for (y = 0; y < fragment_height; y++) {
1905
1906 /* for each fragment in a row... */
1907 for (x = 0; x < fragment_width; x++, i++) {
1908
1909 /* reverse prediction if this block was coded */
1910 if (s->all_fragments[i].coding_method != MODE_COPY) {
1911
1912 current_frame_type =
1913 compatible_frame[s->all_fragments[i].coding_method];
1914 predictor_group = (x == 0) + ((y == 0) << 1) +
1915 ((x + 1 == fragment_width) << 2);
1916 debug_dc_pred(" frag %d: group %d, orig DC = %d, ",
1917 i, predictor_group, s->all_fragments[i].coeffs[0]);
1918
1919 switch (predictor_group) {
1920
1921 case 0:
1922 /* main body of fragments; consider all 4 possible
1923 * fragments for prediction */
1924
1925 /* calculate the indices of the predicting fragments */
1926 ul = i - fragment_width - 1;
1927 u = i - fragment_width;
1928 ur = i - fragment_width + 1;
1929 l = i - 1;
1930
1931 /* fetch the DC values for the predicting fragments */
1932 vul = s->all_fragments[ul].coeffs[0];
1933 vu = s->all_fragments[u].coeffs[0];
1934 vur = s->all_fragments[ur].coeffs[0];
1935 vl = s->all_fragments[l].coeffs[0];
1936
1937 /* figure out which fragments are valid */
1938 ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul);
1939 fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
1940 fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur);
1941 fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
1942
1943 /* decide which predictor transform to use */
1944 transform = (fl*PL) | (fu*PU) | (ful*PUL) | (fur*PUR);
1945
1946 break;
1947
1948 case 1:
1949 /* left column of fragments, not including top corner;
1950 * only consider up and up-right fragments */
1951
1952 /* calculate the indices of the predicting fragments */
1953 u = i - fragment_width;
1954 ur = i - fragment_width + 1;
1955
1956 /* fetch the DC values for the predicting fragments */
1957 vu = s->all_fragments[u].coeffs[0];
1958 vur = s->all_fragments[ur].coeffs[0];
1959
1960 /* figure out which fragments are valid */
1961 fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur);
1962 fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
1963
1964 /* decide which predictor transform to use */
1965 transform = (fu*PU) | (fur*PUR);
1966
1967 break;
1968
1969 case 2:
1970 case 6:
1971 /* top row of fragments, not including top-left frag;
1972 * only consider the left fragment for prediction */
1973
1974 /* calculate the indices of the predicting fragments */
1975 l = i - 1;
1976
1977 /* fetch the DC values for the predicting fragments */
1978 vl = s->all_fragments[l].coeffs[0];
1979
1980 /* figure out which fragments are valid */
1981 fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
1982
1983 /* decide which predictor transform to use */
1984 transform = (fl*PL);
1985
1986 break;
1987
1988 case 3:
1989 /* top-left fragment */
1990
1991 /* nothing to predict from in this case */
1992 transform = 0;
1993
1994 break;
1995
1996 case 4:
1997 /* right column of fragments, not including top corner;
1998 * consider up-left, up, and left fragments for
1999 * prediction */
2000
2001 /* calculate the indices of the predicting fragments */
2002 ul = i - fragment_width - 1;
2003 u = i - fragment_width;
2004 l = i - 1;
2005
2006 /* fetch the DC values for the predicting fragments */
2007 vul = s->all_fragments[ul].coeffs[0];
2008 vu = s->all_fragments[u].coeffs[0];
2009 vl = s->all_fragments[l].coeffs[0];
2010
2011 /* figure out which fragments are valid */
2012 ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul);
2013 fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
2014 fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
2015
2016 /* decide which predictor transform to use */
2017 transform = (fl*PL) | (fu*PU) | (ful*PUL);
2018
2019 break;
2020
2021 }
2022
2023 debug_dc_pred("transform = %d, ", transform);
2024
2025 if (transform == 0) {
2026
2027 /* if there were no fragments to predict from, use last
2028 * DC saved */
2029 s->all_fragments[i].coeffs[0] += last_dc[current_frame_type];
2030 debug_dc_pred("from last DC (%d) = %d\n",
2031 current_frame_type, s->all_fragments[i].coeffs[0]);
2032
2033 } else {
2034
2035 /* apply the appropriate predictor transform */
2036 predicted_dc =
2037 (predictor_transform[transform][0] * vul) +
2038 (predictor_transform[transform][1] * vu) +
2039 (predictor_transform[transform][2] * vur) +
2040 (predictor_transform[transform][3] * vl);
2041
2042 /* if there is a shift value in the transform, add
2043 * the sign bit before the shift */
2044 if (predictor_transform[transform][5] != 0) {
2045 predicted_dc += ((predicted_dc >> 15) &
2046 predictor_transform[transform][4]);
2047 predicted_dc >>= predictor_transform[transform][5];
2048 }
2049
2050 /* check for outranging on the [ul u l] and
2051 * [ul u ur l] predictors */
2052 if ((transform == 13) || (transform == 15)) {
2053 if (iabs(predicted_dc - vu) > 128)
2054 predicted_dc = vu;
2055 else if (iabs(predicted_dc - vl) > 128)
2056 predicted_dc = vl;
2057 else if (iabs(predicted_dc - vul) > 128)
2058 predicted_dc = vul;
2059 }
2060
2061 /* at long last, apply the predictor */
2062 s->all_fragments[i].coeffs[0] += predicted_dc;
2063 debug_dc_pred("from pred DC = %d\n",
2064 s->all_fragments[i].coeffs[0]);
2065 }
2066
2067 /* save the DC */
2068 last_dc[current_frame_type] = s->all_fragments[i].coeffs[0];
2069 }
2070 }
2071 }
2072 }
2073
2074 /*
2075 * This function performs the final rendering of each fragment's data
2076 * onto the output frame.
2077 */
2078 static void render_fragments(Vp3DecodeContext *s,
2079 int first_fragment,
2080 int width,
2081 int height,
2082 int plane /* 0 = Y, 1 = U, 2 = V */)
2083 {
2084 int x, y;
2085 int m, n;
2086 int i = first_fragment;
2087 int j;
2088 int16_t *dequantizer;
2089 DCTELEM dequant_block[64];
2090 DCTELEM dequant_block_permuted[64];
2091 unsigned char *output_plane;
2092 unsigned char *last_plane;
2093 unsigned char *golden_plane;
2094 int stride;
2095 int motion_x, motion_y;
2096 int upper_motion_limit, lower_motion_limit;
2097 int motion_halfpel_index;
2098 unsigned int motion_source;
2099
2100 debug_vp3(" vp3: rendering final fragments for %s\n",
2101 (plane == 0) ? "Y plane" : (plane == 1) ? "U plane" : "V plane");
2102
2103 /* set up plane-specific parameters */
2104 if (plane == 0) {
2105 dequantizer = s->intra_y_dequant;
2106 output_plane = s->current_frame.data[0];
2107 last_plane = s->last_frame.data[0];
2108 golden_plane = s->golden_frame.data[0];
2109 stride = -s->current_frame.linesize[0];
2110 upper_motion_limit = 7 * s->current_frame.linesize[0];
2111 lower_motion_limit = height * s->current_frame.linesize[0] + width - 8;
2112 } else if (plane == 1) {
2113 dequantizer = s->intra_c_dequant;
2114 output_plane = s->current_frame.data[1];
2115 last_plane = s->last_frame.data[1];
2116 golden_plane = s->golden_frame.data[1];
2117 stride = -s->current_frame.linesize[1];
2118 upper_motion_limit = 7 * s->current_frame.linesize[1];
2119 lower_motion_limit = height * s->current_frame.linesize[1] + width - 8;
2120 } else {
2121 dequantizer = s->intra_c_dequant;
2122 output_plane = s->current_frame.data[2];
2123 last_plane = s->last_frame.data[2];
2124 golden_plane = s->golden_frame.data[2];
2125 stride = -s->current_frame.linesize[2];
2126 upper_motion_limit = 7 * s->current_frame.linesize[2];
2127 lower_motion_limit = height * s->current_frame.linesize[2] + width - 8;
2128 }
2129
2130 /* for each fragment row... */
2131 for (y = 0; y < height; y += 8) {
2132
2133 /* for each fragment in a row... */
2134 for (x = 0; x < width; x += 8, i++) {
2135
2136 if ((i < 0) || (i >= s->fragment_count)) {
2137 printf (" vp3:render_fragments(): bad fragment number (%d)\n", i);
2138 return;
2139 }
2140
2141 /* transform if this block was coded */
2142 if (s->all_fragments[i].coding_method != MODE_COPY) {
2143
2144 /* sort out the motion vector */
2145 motion_x = s->all_fragments[i].motion_x;
2146 motion_y = s->all_fragments[i].motion_y;
2147 motion_halfpel_index = s->all_fragments[i].motion_halfpel_index;
2148
2149 motion_source = s->all_fragments[i].first_pixel;
2150 motion_source += motion_x;
2151 motion_source += (motion_y * stride);
2152
2153 /* if the are any problems with a motion vector, refuse
2154 * to render the block */
2155 if ((motion_source < upper_motion_limit) ||
2156 (motion_source > lower_motion_limit)) {
2157 // printf (" vp3: help! motion source (%d) out of range (%d..%d)\n",
2158 // motion_source, upper_motion_limit, lower_motion_limit);
2159 continue;
2160 }
2161
2162 /* first, take care of copying a block from either the
2163 * previous or the golden frame */
2164 if ((s->all_fragments[i].coding_method == MODE_USING_GOLDEN) ||
2165 (s->all_fragments[i].coding_method == MODE_GOLDEN_MV)) {
2166
2167 s->dsp.put_pixels_tab[1][motion_halfpel_index](
2168 output_plane + s->all_fragments[i].first_pixel,
2169 golden_plane + motion_source,
2170 stride, 8);
2171
2172 } else
2173 if (s->all_fragments[i].coding_method != MODE_INTRA) {
2174
2175 s->dsp.put_pixels_tab[1][motion_halfpel_index](
2176 output_plane + s->all_fragments[i].first_pixel,
2177 last_plane + motion_source,
2178 stride, 8);
2179 }
2180
2181 /* dequantize the DCT coefficients */
2182 debug_idct("fragment %d, coding mode %d, DC = %d, dequant = %d:\n",
2183 i, s->all_fragments[i].coding_method,
2184 s->all_fragments[i].coeffs[0], dequantizer[0]);
2185 for (j = 0; j < 64; j++)
2186 dequant_block[dezigzag_index[j]] =
2187 s->all_fragments[i].coeffs[j] *
2188 dequantizer[j];
2189 for (j = 0; j < 64; j++)
2190 dequant_block_permuted[s->dsp.idct_permutation[j]] =
2191 dequant_block[j];
2192
2193 debug_idct("dequantized block:\n");
2194 for (m = 0; m < 8; m++) {
2195 for (n = 0; n < 8; n++) {
2196 debug_idct(" %5d", dequant_block[m * 8 + n]);
2197 }
2198 debug_idct("\n");
2199 }
2200 debug_idct("\n");
2201
2202 /* invert DCT and place (or add) in final output */
2203
2204 if (s->all_fragments[i].coding_method == MODE_INTRA) {
2205 dequant_block_permuted[0] += 1024;
2206 s->dsp.idct_put(
2207 output_plane + s->all_fragments[i].first_pixel,
2208 stride, dequant_block_permuted);
2209 } else {
2210 s->dsp.idct_add(
2211 output_plane + s->all_fragments[i].first_pixel,
2212 stride, dequant_block_permuted);
2213 }
2214
2215 debug_idct("block after idct_%s():\n",
2216 (s->all_fragments[i].coding_method == MODE_INTRA)?
2217 "put" : "add");
2218 for (m = 0; m < 8; m++) {
2219 for (n = 0; n < 8; n++) {
2220 debug_idct(" %3d", *(output_plane +
2221 s->all_fragments[i].first_pixel + (m * stride + n)));
2222 }
2223 debug_idct("\n");
2224 }
2225 debug_idct("\n");
2226
2227 } else {
2228
2229 /* copy directly from the previous frame */
2230 s->dsp.put_pixels_tab[1][0](
2231 output_plane + s->all_fragments[i].first_pixel,
2232 last_plane + s->all_fragments[i].first_pixel,
2233 stride, 8);
2234
2235 }
2236 }
2237 }
2238
2239 emms_c();
2240
2241 }
2242
2243 /*
2244 * This function computes the first pixel addresses for each fragment.
2245 * This function needs to be invoked after the first frame is allocated
2246 * so that it has access to the plane strides.
2247 */
2248 static void vp3_calculate_pixel_addresses(Vp3DecodeContext *s)
2249 {
2250
2251 int i, x, y;
2252
2253 /* figure out the first pixel addresses for each of the fragments */
2254 /* Y plane */
2255 i = 0;
2256 for (y = s->fragment_height; y > 0; y--) {
2257 for (x = 0; x < s->fragment_width; x++) {
2258 s->all_fragments[i++].first_pixel =
2259 s->golden_frame.linesize[0] * y * FRAGMENT_PIXELS -
2260 s->golden_frame.linesize[0] +
2261 x * FRAGMENT_PIXELS;
2262 debug_init(" fragment %d, first pixel @ %d\n",
2263 i-1, s->all_fragments[i-1].first_pixel);
2264 }
2265 }
2266
2267 /* U plane */
2268 i = s->u_fragment_start;
2269 for (y = s->fragment_height / 2; y > 0; y--) {
2270 for (x = 0; x < s->fragment_width / 2; x++) {
2271 s->all_fragments[i++].first_pixel =
2272 s->golden_frame.linesize[1] * y * FRAGMENT_PIXELS -
2273 s->golden_frame.linesize[1] +
2274 x * FRAGMENT_PIXELS;
2275 debug_init(" fragment %d, first pixel @ %d\n",
2276 i-1, s->all_fragments[i-1].first_pixel);
2277 }
2278 }
2279
2280 /* V plane */
2281 i = s->v_fragment_start;
2282 for (y = s->fragment_height / 2; y > 0; y--) {
2283 for (x = 0; x < s->fragment_width / 2; x++) {
2284 s->all_fragments[i++].first_pixel =
2285 s->golden_frame.linesize[2] * y * FRAGMENT_PIXELS -
2286 s->golden_frame.linesize[2] +
2287 x * FRAGMENT_PIXELS;
2288 debug_init(" fragment %d, first pixel @ %d\n",
2289 i-1, s->all_fragments[i-1].first_pixel);
2290 }
2291 }
2292 }
2293
2294 /*
2295 * This is the ffmpeg/libavcodec API init function.
2296 */
2297 static int vp3_decode_init(AVCodecContext *avctx)
2298 {
2299 Vp3DecodeContext *s = avctx->priv_data;
2300 int i;
2301 int c_width;
2302 int c_height;
2303 int y_superblock_count;
2304 int c_superblock_count;
2305
2306 s->avctx = avctx;
2307 s->width = avctx->width;
2308 s->height = avctx->height;
2309 avctx->pix_fmt = PIX_FMT_YUV420P;
2310 avctx->has_b_frames = 0;
2311 dsputil_init(&s->dsp, avctx);
2312
2313 /* initialize to an impossible value which will force a recalculation
2314 * in the first frame decode */
2315 s->quality_index = -1;
2316
2317 s->y_superblock_width = (s->width + 31) / 32;
2318 s->y_superblock_height = (s->height + 31) / 32;
2319 y_superblock_count = s->y_superblock_width * s->y_superblock_height;
2320
2321 /* work out the dimensions for the C planes */
2322 c_width = s->width / 2;
2323 c_height = s->height / 2;
2324 s->c_superblock_width = (c_width + 31) / 32;
2325 s->c_superblock_height = (c_height + 31) / 32;
2326 c_superblock_count = s->c_superblock_width * s->c_superblock_height;
2327
2328 s->superblock_count = y_superblock_count + (c_superblock_count * 2);
2329 s->u_superblock_start = y_superblock_count;
2330 s->v_superblock_start = s->u_superblock_start + c_superblock_count;
2331 s->superblock_coding = av_malloc(s->superblock_count);
2332
2333 s->macroblock_width = (s->width + 15) / 16;
2334 s->macroblock_height = (s->height + 15) / 16;
2335 s->macroblock_count = s->macroblock_width * s->macroblock_height;
2336
2337 s->fragment_width = s->width / FRAGMENT_PIXELS;
2338 s->fragment_height = s->height / FRAGMENT_PIXELS;
2339
2340 /* fragment count covers all 8x8 blocks for all 3 planes */
2341 s->fragment_count = s->fragment_width * s->fragment_height * 3 / 2;
2342 s->u_fragment_start = s->fragment_width * s->fragment_height;
2343 s->v_fragment_start = s->fragment_width * s->fragment_height * 5 / 4;
2344
2345 debug_init(" Y plane: %d x %d\n", s->width, s->height);
2346 debug_init(" C plane: %d x %d\n", c_width, c_height);
2347 debug_init(" Y superblocks: %d x %d, %d total\n",
2348 s->y_superblock_width, s->y_superblock_height, y_superblock_count);
2349 debug_init(" C superblocks: %d x %d, %d total\n",
2350 s->c_superblock_width, s->c_superblock_height, c_superblock_count);
2351 debug_init(" total superblocks = %d, U starts @ %d, V starts @ %d\n",
2352 s->superblock_count, s->u_superblock_start, s->v_superblock_start);
2353 debug_init(" macroblocks: %d x %d, %d total\n",
2354 s->macroblock_width, s->macroblock_height, s->macroblock_count);
2355 debug_init(" %d fragments, %d x %d, u starts @ %d, v starts @ %d\n",
2356 s->fragment_count,
2357 s->fragment_width,
2358 s->fragment_height,
2359 s->u_fragment_start,
2360 s->v_fragment_start);
2361
2362 s->all_fragments = av_malloc(s->fragment_count * sizeof(Vp3Fragment));
2363 s->coded_fragment_list = av_malloc(s->fragment_count * sizeof(int));
2364 s->pixel_addresses_inited = 0;
2365
2366 /* init VLC tables */
2367 for (i = 0; i < 16; i++) {
2368
2369 /* DC histograms */
2370 init_vlc(&s->dc_vlc[i], 5, 32,
2371 &dc_bias[i][0][1], 4, 2,
2372 &dc_bias[i][0][0], 4, 2);
2373
2374 /* group 1 AC histograms */
2375 init_vlc(&s->ac_vlc_1[i], 5, 32,
2376 &ac_bias_0[i][0][1], 4, 2,
2377 &ac_bias_0[i][0][0], 4, 2);
2378
2379 /* group 2 AC histograms */
2380 init_vlc(&s->ac_vlc_2[i], 5, 32,
2381 &ac_bias_1[i][0][1], 4, 2,
2382 &ac_bias_1[i][0][0], 4, 2);
2383
2384 /* group 3 AC histograms */
2385 init_vlc(&s->ac_vlc_3[i], 5, 32,
2386 &ac_bias_2[i][0][1], 4, 2,
2387 &ac_bias_2[i][0][0], 4, 2);
2388
2389 /* group 4 AC histograms */
2390 init_vlc(&s->ac_vlc_4[i], 5, 32,
2391 &ac_bias_3[i][0][1], 4, 2,
2392 &ac_bias_3[i][0][0], 4, 2);
2393 }
2394
2395 /* build quantization zigzag table */
2396 for (i = 0; i < 64; i++)
2397 zigzag_index[dezigzag_index[i]] = i;
2398
2399 /* work out the block mapping tables */
2400 s->superblock_fragments = av_malloc(s->superblock_count * 16 * sizeof(int));
2401 s->superblock_macroblocks = av_malloc(s->superblock_count * 4 * sizeof(int));
2402 s->macroblock_fragments = av_malloc(s->macroblock_count * 6 * sizeof(int));
2403 s->macroblock_coding = av_malloc(s->macroblock_count + 1);
2404 init_block_mapping(s);
2405
2406 for (i = 0; i < 3; i++) {
2407 s->current_frame.data[i] = NULL;
2408 s->last_frame.data[i] = NULL;
2409 s->golden_frame.data[i] = NULL;
2410 }
2411
2412 return 0;
2413 }
2414
2415 /*
2416 * This is the ffmpeg/libavcodec API frame decode function.
2417 */
2418 static int vp3_decode_frame(AVCodecContext *avctx,
2419 void *data, int *data_size,
2420 uint8_t *buf, int buf_size)
2421 {
2422 Vp3DecodeContext *s = avctx->priv_data;
2423 GetBitContext gb;
2424 static int counter = 0;
2425
2426 *data_size = 0;
2427
2428 init_get_bits(&gb, buf, buf_size * 8);
2429
2430 s->keyframe = get_bits(&gb, 1);
2431 s->keyframe ^= 1;
2432 skip_bits(&gb, 1);
2433 s->last_quality_index = s->quality_index;
2434 s->quality_index = get_bits(&gb, 6);
2435 if (s->quality_index != s->last_quality_index)
2436 init_dequantizer(s);
2437
2438 debug_vp3(" VP3 frame #%d: Q index = %d", counter, s->quality_index);
2439 counter++;
2440
2441 if (s->keyframe) {
2442
2443 debug_vp3(", keyframe\n");
2444 /* skip the other 2 header bytes for now */
2445 skip_bits(&gb, 16);
2446
2447 if (s->last_frame.data[0] == s->golden_frame.data[0]) {
2448 if (s->golden_frame.data[0])
2449 avctx->release_buffer(avctx, &s->golden_frame);
2450 } else {
2451 if (s->golden_frame.data[0])
2452 avctx->release_buffer(avctx, &s->golden_frame);
2453 if (s->last_frame.data[0])
2454 avctx->release_buffer(avctx, &s->last_frame);
2455 }
2456
2457 s->golden_frame.reference = 0;
2458 if(avctx->get_buffer(avctx, &s->golden_frame) < 0) {
2459 printf("vp3: get_buffer() failed\n");
2460 return -1;
2461 }
2462
2463 /* golden frame is also the current frame */
2464 memcpy(&s->current_frame, &s->golden_frame, sizeof(AVFrame));
2465
2466 /* time to figure out pixel addresses? */
2467 if (!s->pixel_addresses_inited)
2468 vp3_calculate_pixel_addresses(s);
2469
2470 } else {
2471
2472 debug_vp3("\n");
2473
2474 /* allocate a new current frame */
2475 s->current_frame.reference = 0;
2476 if(avctx->get_buffer(avctx, &s->current_frame) < 0) {
2477 printf("vp3: get_buffer() failed\n");
2478 return -1;
2479 }
2480 }
2481
2482 init_frame(s, &gb);
2483
2484 #if KEYFRAMES_ONLY
2485 if (!s->keyframe) {
2486
2487 memcpy(s->current_frame.data[0], s->golden_frame.data[0],
2488 s->current_frame.linesize[0] * s->height);
2489 memcpy(s->current_frame.data[1], s->golden_frame.data[1],
2490 s->current_frame.linesize[1] * s->height / 2);
2491 memcpy(s->current_frame.data[2], s->golden_frame.data[2],
2492 s->current_frame.linesize[2] * s->height / 2);
2493
2494 } else {
2495 #endif
2496
2497 if (unpack_superblocks(s, &gb) ||
2498 unpack_modes(s, &gb) ||
2499 unpack_vectors(s, &gb) ||
2500 unpack_dct_coeffs(s, &gb)) {
2501
2502 printf(" vp3: could not decode frame\n");
2503 return -1;
2504 }
2505
2506 reverse_dc_prediction(s, 0, s->fragment_width, s->fragment_height);
2507 reverse_dc_prediction(s, s->u_fragment_start,
2508 s->fragment_width / 2, s->fragment_height / 2);
2509 reverse_dc_prediction(s, s->v_fragment_start,
2510 s->fragment_width / 2, s->fragment_height / 2);
2511
2512 render_fragments(s, 0, s->width, s->height, 0);
2513 render_fragments(s, s->u_fragment_start, s->width / 2, s->height / 2, 1);
2514 render_fragments(s, s->v_fragment_start, s->width / 2, s->height / 2, 2);
2515
2516 #if KEYFRAMES_ONLY
2517 }
2518 #endif
2519
2520 *data_size=sizeof(AVFrame);
2521 *(AVFrame*)data= s->current_frame;
2522
2523 /* release the last frame, if it is allocated and if it is not the
2524 * golden frame */
2525 if ((s->last_frame.data[0]) &&
2526 (s->last_frame.data[0] != s->golden_frame.data[0]))
2527 avctx->release_buffer(avctx, &s->last_frame);
2528
2529 /* shuffle frames (last = current) */
2530 memcpy(&s->last_frame, &s->current_frame, sizeof(AVFrame));
2531
2532 return buf_size;
2533 }
2534
2535 /*
2536 * This is the ffmpeg/libavcodec API module cleanup function.
2537 */
2538 static int vp3_decode_end(AVCodecContext *avctx)
2539 {
2540 Vp3DecodeContext *s = avctx->priv_data;
2541
2542 av_free(s->all_fragments);
2543 av_free(s->coded_fragment_list);
2544 av_free(s->superblock_fragments);
2545 av_free(s->superblock_macroblocks);
2546 av_free(s->macroblock_fragments);
2547 av_free(s->macroblock_coding);
2548
2549 /* release all frames */
2550 if (s->golden_frame.data[0])
2551 avctx->release_buffer(avctx, &s->golden_frame);
2552 if (s->last_frame.data[0])
2553 avctx->release_buffer(avctx, &s->last_frame);
2554 /* no need to release the current_frame since it will always be pointing
2555 * to the same frame as either the golden or last frame */
2556
2557 return 0;
2558 }
2559
2560 AVCodec vp3_decoder = {
2561 "vp3",
2562 CODEC_TYPE_VIDEO,
2563 CODEC_ID_VP3,
2564 sizeof(Vp3DecodeContext),
2565 vp3_decode_init,
2566 NULL,
2567 vp3_decode_end,
2568 vp3_decode_frame,
2569 0,
2570 NULL
2571 };