10l
[libav.git] / libavcodec / mpeg12.c
1 /*
2 * MPEG1 encoder / MPEG2 decoder
3 * Copyright (c) 2000,2001 Fabrice Bellard.
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 //#define DEBUG
20 #include "avcodec.h"
21 #include "dsputil.h"
22 #include "mpegvideo.h"
23
24 #include "mpeg12data.h"
25
26 #if 1
27 #define PRINT_QP(a, b) {}
28 #else
29 #define PRINT_QP(a, b) printf(a, b)
30 #endif
31
32 /* Start codes. */
33 #define SEQ_END_CODE 0x000001b7
34 #define SEQ_START_CODE 0x000001b3
35 #define GOP_START_CODE 0x000001b8
36 #define PICTURE_START_CODE 0x00000100
37 #define SLICE_MIN_START_CODE 0x00000101
38 #define SLICE_MAX_START_CODE 0x000001af
39 #define EXT_START_CODE 0x000001b5
40 #define USER_START_CODE 0x000001b2
41
42 #define DC_VLC_BITS 9
43 #define MV_VLC_BITS 9
44 #define MBINCR_VLC_BITS 9
45 #define MB_PAT_VLC_BITS 9
46 #define MB_PTYPE_VLC_BITS 6
47 #define MB_BTYPE_VLC_BITS 6
48 #define TEX_VLC_BITS 9
49
50 static void mpeg1_encode_block(MpegEncContext *s,
51 DCTELEM *block,
52 int component);
53 static void mpeg1_encode_motion(MpegEncContext *s, int val);
54 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
55 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
56 DCTELEM *block,
57 int n);
58 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
59 DCTELEM *block,
60 int n);
61 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
62 DCTELEM *block,
63 int n);
64 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
65 DCTELEM *block,
66 int n);
67 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
68
69 static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
70 static UINT8 fcode_tab[MAX_MV*2+1];
71
72 static inline int get_bits_diff(MpegEncContext *s){
73 int bits,ret;
74
75 bits= get_bit_count(&s->pb);
76 ret= bits - s->last_bits;
77 s->last_bits=bits;
78
79 return ret;
80 }
81
82 static void init_2d_vlc_rl(RLTable *rl)
83 {
84 int i;
85
86 init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2,
87 &rl->table_vlc[0][1], 4, 2,
88 &rl->table_vlc[0][0], 4, 2);
89
90
91 rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
92 for(i=0; i<rl->vlc.table_size; i++){
93 int code= rl->vlc.table[i][0];
94 int len = rl->vlc.table[i][1];
95 int level, run;
96
97 if(len==0){ // illegal code
98 run= 65;
99 level= MAX_LEVEL;
100 }else if(len<0){ //more bits needed
101 run= 0;
102 level= code;
103 }else{
104 if(code==rl->n){ //esc
105 run= 65;
106 level= 0;
107 }else if(code==rl->n+1){ //eob
108 run= 0;
109 level= 127;
110 }else{
111 run= rl->table_run [code] + 1;
112 level= rl->table_level[code];
113 }
114 }
115 rl->rl_vlc[0][i].len= len;
116 rl->rl_vlc[0][i].level= level;
117 rl->rl_vlc[0][i].run= run;
118 }
119 }
120
121
122 static void put_header(MpegEncContext *s, int header)
123 {
124 align_put_bits(&s->pb);
125 put_bits(&s->pb, 16, header>>16);
126 put_bits(&s->pb, 16, header&0xFFFF);
127 }
128
129 /* put sequence header if needed */
130 static void mpeg1_encode_sequence_header(MpegEncContext *s)
131 {
132 unsigned int vbv_buffer_size;
133 unsigned int fps, v;
134 int n;
135 UINT64 time_code;
136
137 if (s->picture_in_gop_number == 0) {
138 /* mpeg1 header repeated every gop */
139 put_header(s, SEQ_START_CODE);
140
141 /* search closest frame rate */
142 {
143 int i, dmin, d;
144 s->frame_rate_index = 0;
145 dmin = 0x7fffffff;
146 for(i=1;i<9;i++) {
147 d = abs(s->frame_rate - frame_rate_tab[i]);
148 if (d < dmin) {
149 dmin = d;
150 s->frame_rate_index = i;
151 }
152 }
153 }
154
155 put_bits(&s->pb, 12, s->width);
156 put_bits(&s->pb, 12, s->height);
157 put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
158 put_bits(&s->pb, 4, s->frame_rate_index);
159 v = s->bit_rate / 400;
160 if (v > 0x3ffff)
161 v = 0x3ffff;
162 put_bits(&s->pb, 18, v);
163 put_bits(&s->pb, 1, 1); /* marker */
164
165 if(s->avctx->rc_buffer_size)
166 vbv_buffer_size = s->avctx->rc_buffer_size;
167 else
168 /* VBV calculation: Scaled so that a VCD has the proper VBV size of 40 kilobytes */
169 vbv_buffer_size = (( 20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;
170 put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
171 put_bits(&s->pb, 1, 1); /* constrained parameter flag */
172 put_bits(&s->pb, 1, 0); /* no custom intra matrix */
173 put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
174
175 put_header(s, GOP_START_CODE);
176 put_bits(&s->pb, 1, 0); /* do drop frame */
177 /* time code : we must convert from the real frame rate to a
178 fake mpeg frame rate in case of low frame rate */
179 fps = frame_rate_tab[s->frame_rate_index];
180 time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
181 s->gop_picture_number = s->fake_picture_number;
182 put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
183 put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
184 put_bits(&s->pb, 1, 1);
185 put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
186 put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
187 put_bits(&s->pb, 1, 1); /* closed gop */
188 put_bits(&s->pb, 1, 0); /* broken link */
189 }
190
191 if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
192 /* insert empty P pictures to slow down to the desired
193 frame rate. Each fake pictures takes about 20 bytes */
194 fps = frame_rate_tab[s->frame_rate_index];
195 n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
196 while (s->fake_picture_number < n) {
197 mpeg1_skip_picture(s, s->fake_picture_number -
198 s->gop_picture_number);
199 s->fake_picture_number++;
200 }
201
202 }
203 }
204
205
206 /* insert a fake P picture */
207 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
208 {
209 unsigned int mb_incr;
210
211 /* mpeg1 picture header */
212 put_header(s, PICTURE_START_CODE);
213 /* temporal reference */
214 put_bits(&s->pb, 10, pict_num & 0x3ff);
215
216 put_bits(&s->pb, 3, P_TYPE);
217 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
218
219 put_bits(&s->pb, 1, 1); /* integer coordinates */
220 put_bits(&s->pb, 3, 1); /* forward_f_code */
221
222 put_bits(&s->pb, 1, 0); /* extra bit picture */
223
224 /* only one slice */
225 put_header(s, SLICE_MIN_START_CODE);
226 put_bits(&s->pb, 5, 1); /* quantizer scale */
227 put_bits(&s->pb, 1, 0); /* slice extra information */
228
229 mb_incr = 1;
230 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
231 mbAddrIncrTable[mb_incr - 1][0]);
232
233 /* empty macroblock */
234 put_bits(&s->pb, 3, 1); /* motion only */
235
236 /* zero motion x & y */
237 put_bits(&s->pb, 1, 1);
238 put_bits(&s->pb, 1, 1);
239
240 /* output a number of empty slice */
241 mb_incr = s->mb_width * s->mb_height - 1;
242 while (mb_incr > 33) {
243 put_bits(&s->pb, 11, 0x008);
244 mb_incr -= 33;
245 }
246 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
247 mbAddrIncrTable[mb_incr - 1][0]);
248
249 /* empty macroblock */
250 put_bits(&s->pb, 3, 1); /* motion only */
251
252 /* zero motion x & y */
253 put_bits(&s->pb, 1, 1);
254 put_bits(&s->pb, 1, 1);
255 }
256
257 static void common_init(MpegEncContext *s)
258 {
259 s->y_dc_scale_table=
260 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
261 }
262
263 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
264 {
265 mpeg1_encode_sequence_header(s);
266
267 /* mpeg1 picture header */
268 put_header(s, PICTURE_START_CODE);
269 /* temporal reference */
270 put_bits(&s->pb, 10, (s->fake_picture_number -
271 s->gop_picture_number) & 0x3ff);
272 s->fake_picture_number++;
273
274 put_bits(&s->pb, 3, s->pict_type);
275 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
276
277 if (s->pict_type == P_TYPE) {
278 put_bits(&s->pb, 1, 0); /* half pel coordinates */
279 put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
280 }
281
282 put_bits(&s->pb, 1, 0); /* extra bit picture */
283
284 /* only one slice */
285 put_header(s, SLICE_MIN_START_CODE);
286 put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
287 put_bits(&s->pb, 1, 0); /* slice extra information */
288 }
289
290 void mpeg1_encode_mb(MpegEncContext *s,
291 DCTELEM block[6][64],
292 int motion_x, int motion_y)
293 {
294 int mb_incr, i, cbp, mb_x, mb_y;
295
296 mb_x = s->mb_x;
297 mb_y = s->mb_y;
298
299 /* compute cbp */
300 cbp = 0;
301 for(i=0;i<6;i++) {
302 if (s->block_last_index[i] >= 0)
303 cbp |= 1 << (5 - i);
304 }
305
306 /* skip macroblock, except if first or last macroblock of a slice */
307 if ((cbp | motion_x | motion_y) == 0 &&
308 (!((mb_x | mb_y) == 0 ||
309 (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
310 s->mb_incr++;
311 s->qscale -= s->dquant;
312 s->skip_count++;
313 s->misc_bits++;
314 s->last_bits++;
315 } else {
316 /* output mb incr */
317 mb_incr = s->mb_incr;
318
319 while (mb_incr > 33) {
320 put_bits(&s->pb, 11, 0x008);
321 mb_incr -= 33;
322 }
323 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
324 mbAddrIncrTable[mb_incr - 1][0]);
325
326 if (s->pict_type == I_TYPE) {
327 if(s->dquant && cbp){
328 put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
329 put_bits(&s->pb, 5, s->qscale);
330 }else{
331 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
332 s->qscale -= s->dquant;
333 }
334 s->misc_bits+= get_bits_diff(s);
335 s->i_count++;
336 } else {
337 if (s->mb_intra) {
338 if(s->dquant && cbp){
339 put_bits(&s->pb, 6, 0x01);
340 put_bits(&s->pb, 5, s->qscale);
341 }else{
342 put_bits(&s->pb, 5, 0x03);
343 s->qscale -= s->dquant;
344 }
345 s->misc_bits+= get_bits_diff(s);
346 s->i_count++;
347 } else {
348 if (cbp != 0) {
349 if (motion_x == 0 && motion_y == 0) {
350 if(s->dquant){
351 put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
352 put_bits(&s->pb, 5, s->qscale);
353 }else{
354 put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
355 }
356 s->misc_bits+= get_bits_diff(s);
357 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
358 } else {
359 if(s->dquant){
360 put_bits(&s->pb, 5, 2); /* motion + cbp */
361 put_bits(&s->pb, 5, s->qscale);
362 }else{
363 put_bits(&s->pb, 1, 1); /* motion + cbp */
364 }
365 s->misc_bits+= get_bits_diff(s);
366 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
367 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
368 s->mv_bits+= get_bits_diff(s);
369 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
370 }
371 } else {
372 put_bits(&s->pb, 3, 1); /* motion only */
373 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
374 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
375 s->qscale -= s->dquant;
376 s->mv_bits+= get_bits_diff(s);
377 }
378 s->f_count++;
379 }
380 }
381 for(i=0;i<6;i++) {
382 if (cbp & (1 << (5 - i))) {
383 mpeg1_encode_block(s, block[i], i);
384 }
385 }
386 s->mb_incr = 1;
387 if(s->mb_intra)
388 s->i_tex_bits+= get_bits_diff(s);
389 else
390 s->p_tex_bits+= get_bits_diff(s);
391 }
392 s->last_mv[0][0][0] = motion_x;
393 s->last_mv[0][0][1] = motion_y;
394 }
395
396 static void mpeg1_encode_motion(MpegEncContext *s, int val)
397 {
398 int code, bit_size, l, m, bits, range, sign;
399
400 if (val == 0) {
401 /* zero vector */
402 code = 0;
403 put_bits(&s->pb,
404 mbMotionVectorTable[0][1],
405 mbMotionVectorTable[0][0]);
406 } else {
407 bit_size = s->f_code - 1;
408 range = 1 << bit_size;
409 /* modulo encoding */
410 l = 16 * range;
411 m = 2 * l;
412 if (val < -l) {
413 val += m;
414 } else if (val >= l) {
415 val -= m;
416 }
417
418 if (val >= 0) {
419 val--;
420 code = (val >> bit_size) + 1;
421 bits = val & (range - 1);
422 sign = 0;
423 } else {
424 val = -val;
425 val--;
426 code = (val >> bit_size) + 1;
427 bits = val & (range - 1);
428 sign = 1;
429 }
430 put_bits(&s->pb,
431 mbMotionVectorTable[code][1],
432 mbMotionVectorTable[code][0]);
433 put_bits(&s->pb, 1, sign);
434 if (bit_size > 0) {
435 put_bits(&s->pb, bit_size, bits);
436 }
437 }
438 }
439
440 void ff_mpeg1_encode_init(MpegEncContext *s)
441 {
442 static int done=0;
443
444 common_init(s);
445
446 if(!done){
447 int f_code;
448 int mv;
449 int i;
450
451 done=1;
452 init_rl(&rl_mpeg1);
453
454 for(i=0; i<64; i++)
455 {
456 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
457 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
458 }
459
460 /* build unified dc encoding tables */
461 for(i=-255; i<256; i++)
462 {
463 int adiff, index;
464 int bits, code;
465 int diff=i;
466
467 adiff = ABS(diff);
468 if(diff<0) diff--;
469 index = vlc_dc_table[adiff];
470
471 bits= vlc_dc_lum_bits[index] + index;
472 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
473 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
474
475 bits= vlc_dc_chroma_bits[index] + index;
476 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
477 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
478 }
479
480 for(f_code=1; f_code<=MAX_FCODE; f_code++){
481 for(mv=-MAX_MV; mv<=MAX_MV; mv++){
482 int len;
483
484 if(mv==0) len= mbMotionVectorTable[0][1];
485 else{
486 int val, bit_size, range, code;
487
488 bit_size = s->f_code - 1;
489 range = 1 << bit_size;
490
491 val=mv;
492 if (val < 0)
493 val = -val;
494 val--;
495 code = (val >> bit_size) + 1;
496 if(code<17){
497 len= mbMotionVectorTable[code][1] + 1 + bit_size;
498 }else{
499 len= mbMotionVectorTable[16][1] + 2 + bit_size;
500 }
501 }
502
503 mv_penalty[f_code][mv+MAX_MV]= len;
504 }
505 }
506
507
508 for(f_code=MAX_FCODE; f_code>0; f_code--){
509 for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
510 fcode_tab[mv+MAX_MV]= f_code;
511 }
512 }
513 }
514 s->mv_penalty= mv_penalty;
515 s->fcode_tab= fcode_tab;
516 s->min_qcoeff=-255;
517 s->max_qcoeff= 255;
518 s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
519 s->inter_quant_bias= 0;
520 }
521
522 static inline void encode_dc(MpegEncContext *s, int diff, int component)
523 {
524 if (component == 0) {
525 put_bits(
526 &s->pb,
527 mpeg1_lum_dc_uni[diff+255]&0xFF,
528 mpeg1_lum_dc_uni[diff+255]>>8);
529 } else {
530 put_bits(
531 &s->pb,
532 mpeg1_chr_dc_uni[diff+255]&0xFF,
533 mpeg1_chr_dc_uni[diff+255]>>8);
534 }
535 }
536
537 static void mpeg1_encode_block(MpegEncContext *s,
538 DCTELEM *block,
539 int n)
540 {
541 int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
542 int code, component;
543 // RLTable *rl = &rl_mpeg1;
544
545 last_index = s->block_last_index[n];
546
547 /* DC coef */
548 if (s->mb_intra) {
549 component = (n <= 3 ? 0 : n - 4 + 1);
550 dc = block[0]; /* overflow is impossible */
551 diff = dc - s->last_dc[component];
552 encode_dc(s, diff, component);
553 s->last_dc[component] = dc;
554 i = 1;
555 } else {
556 /* encode the first coefficient : needs to be done here because
557 it is handled slightly differently */
558 level = block[0];
559 if (abs(level) == 1) {
560 code = ((UINT32)level >> 31); /* the sign bit */
561 put_bits(&s->pb, 2, code | 0x02);
562 i = 1;
563 } else {
564 i = 0;
565 last_non_zero = -1;
566 goto next_coef;
567 }
568 }
569
570 /* now quantify & encode AC coefs */
571 last_non_zero = i - 1;
572
573 for(;i<=last_index;i++) {
574 j = s->intra_scantable.permutated[i];
575 level = block[j];
576 next_coef:
577 #if 0
578 if (level != 0)
579 dprintf("level[%d]=%d\n", i, level);
580 #endif
581 /* encode using VLC */
582 if (level != 0) {
583 run = i - last_non_zero - 1;
584
585 alevel= level;
586 MASK_ABS(sign, alevel)
587 sign&=1;
588
589 // code = get_rl_index(rl, 0, run, alevel);
590 if (alevel > mpeg1_max_level[0][run])
591 code= 111; /*rl->n*/
592 else
593 code= mpeg1_index_run[0][run] + alevel - 1;
594
595 if (code < 111 /* rl->n */) {
596 /* store the vlc & sign at once */
597 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
598 } else {
599 /* escape seems to be pretty rare <5% so i dont optimize it */
600 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
601 /* escape: only clip in this case */
602 put_bits(&s->pb, 6, run);
603 if (alevel < 128) {
604 put_bits(&s->pb, 8, level & 0xff);
605 } else {
606 if (level < 0) {
607 put_bits(&s->pb, 16, 0x8001 + level + 255);
608 } else {
609 put_bits(&s->pb, 16, level & 0xffff);
610 }
611 }
612 }
613 last_non_zero = i;
614 }
615 }
616 /* end of block */
617 put_bits(&s->pb, 2, 0x2);
618 }
619
620 /******************************************/
621 /* decoding */
622
623 static VLC dc_lum_vlc;
624 static VLC dc_chroma_vlc;
625 static VLC mv_vlc;
626 static VLC mbincr_vlc;
627 static VLC mb_ptype_vlc;
628 static VLC mb_btype_vlc;
629 static VLC mb_pat_vlc;
630
631 static void init_vlcs(MpegEncContext *s)
632 {
633 static int done = 0;
634
635 if (!done) {
636 done = 1;
637
638 init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12,
639 vlc_dc_lum_bits, 1, 1,
640 vlc_dc_lum_code, 2, 2);
641 init_vlc(&dc_chroma_vlc, DC_VLC_BITS, 12,
642 vlc_dc_chroma_bits, 1, 1,
643 vlc_dc_chroma_code, 2, 2);
644 init_vlc(&mv_vlc, MV_VLC_BITS, 17,
645 &mbMotionVectorTable[0][1], 2, 1,
646 &mbMotionVectorTable[0][0], 2, 1);
647 init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 35,
648 &mbAddrIncrTable[0][1], 2, 1,
649 &mbAddrIncrTable[0][0], 2, 1);
650 init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63,
651 &mbPatTable[0][1], 2, 1,
652 &mbPatTable[0][0], 2, 1);
653
654 init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 32,
655 &table_mb_ptype[0][1], 2, 1,
656 &table_mb_ptype[0][0], 2, 1);
657 init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 32,
658 &table_mb_btype[0][1], 2, 1,
659 &table_mb_btype[0][0], 2, 1);
660 init_rl(&rl_mpeg1);
661 init_rl(&rl_mpeg2);
662
663 init_2d_vlc_rl(&rl_mpeg1);
664 init_2d_vlc_rl(&rl_mpeg2);
665 }
666 }
667
668 static inline int get_dmv(MpegEncContext *s)
669 {
670 if(get_bits1(&s->gb))
671 return 1 - (get_bits1(&s->gb) << 1);
672 else
673 return 0;
674 }
675
676 static inline int get_qscale(MpegEncContext *s)
677 {
678 int qscale;
679 if (s->mpeg2) {
680 if (s->q_scale_type) {
681 qscale = non_linear_qscale[get_bits(&s->gb, 5)];
682 } else {
683 qscale = get_bits(&s->gb, 5) << 1;
684 }
685 } else {
686 /* for mpeg1, we use the generic unquant code */
687 qscale = get_bits(&s->gb, 5);
688 }
689 return qscale;
690 }
691
692 /* motion type (for mpeg2) */
693 #define MT_FIELD 1
694 #define MT_FRAME 2
695 #define MT_16X8 2
696 #define MT_DMV 3
697
698 static int mpeg_decode_mb(MpegEncContext *s,
699 DCTELEM block[6][64])
700 {
701 int i, j, k, cbp, val, mb_type, motion_type;
702
703 dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
704
705 if (--s->mb_incr != 0) {
706 /* skip mb */
707 s->mb_intra = 0;
708 for(i=0;i<6;i++)
709 s->block_last_index[i] = -1;
710 s->mv_type = MV_TYPE_16X16;
711 if (s->pict_type == P_TYPE) {
712 /* if P type, zero motion vector is implied */
713 s->mv_dir = MV_DIR_FORWARD;
714 s->mv[0][0][0] = s->mv[0][0][1] = 0;
715 s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
716 s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
717 } else {
718 /* if B type, reuse previous vectors and directions */
719 s->mv[0][0][0] = s->last_mv[0][0][0];
720 s->mv[0][0][1] = s->last_mv[0][0][1];
721 s->mv[1][0][0] = s->last_mv[1][0][0];
722 s->mv[1][0][1] = s->last_mv[1][0][1];
723 }
724 s->mb_skiped = 1;
725 return 0;
726 }
727
728 switch(s->pict_type) {
729 default:
730 case I_TYPE:
731 if (get_bits1(&s->gb) == 0) {
732 if (get_bits1(&s->gb) == 0)
733 return -1;
734 mb_type = MB_QUANT | MB_INTRA;
735 } else {
736 mb_type = MB_INTRA;
737 }
738 break;
739 case P_TYPE:
740 mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
741 if (mb_type < 0){
742 fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
743 return -1;
744 }
745 break;
746 case B_TYPE:
747 mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
748 if (mb_type < 0){
749 fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
750 return -1;
751 }
752 break;
753 }
754 dprintf("mb_type=%x\n", mb_type);
755 motion_type = 0; /* avoid warning */
756 if (mb_type & (MB_FOR|MB_BACK)) {
757 /* get additionnal motion vector type */
758 if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct)
759 motion_type = MT_FRAME;
760 else
761 motion_type = get_bits(&s->gb, 2);
762 }
763 /* compute dct type */
764 if (s->picture_structure == PICT_FRAME &&
765 !s->frame_pred_frame_dct &&
766 (mb_type & (MB_PAT | MB_INTRA))) {
767 s->interlaced_dct = get_bits1(&s->gb);
768 #ifdef DEBUG
769 if (s->interlaced_dct)
770 printf("interlaced_dct\n");
771 #endif
772 } else {
773 s->interlaced_dct = 0; /* frame based */
774 }
775
776 if (mb_type & MB_QUANT) {
777 s->qscale = get_qscale(s);
778 }
779 if (mb_type & MB_INTRA) {
780 if (s->concealment_motion_vectors) {
781 /* just parse them */
782 if (s->picture_structure != PICT_FRAME)
783 skip_bits1(&s->gb); /* field select */
784 mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
785 mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
786 }
787 s->mb_intra = 1;
788 cbp = 0x3f;
789 memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
790 } else {
791 s->mb_intra = 0;
792 cbp = 0;
793 }
794 /* special case of implicit zero motion vector */
795 if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
796 s->mv_dir = MV_DIR_FORWARD;
797 s->mv_type = MV_TYPE_16X16;
798 s->last_mv[0][0][0] = 0;
799 s->last_mv[0][0][1] = 0;
800 s->last_mv[0][1][0] = 0;
801 s->last_mv[0][1][1] = 0;
802 s->mv[0][0][0] = 0;
803 s->mv[0][0][1] = 0;
804 } else if (mb_type & (MB_FOR | MB_BACK)) {
805 /* motion vectors */
806 s->mv_dir = 0;
807 for(i=0;i<2;i++) {
808 if (mb_type & (MB_FOR >> i)) {
809 s->mv_dir |= (MV_DIR_FORWARD >> i);
810 dprintf("motion_type=%d\n", motion_type);
811 switch(motion_type) {
812 case MT_FRAME: /* or MT_16X8 */
813 if (s->picture_structure == PICT_FRAME) {
814 /* MT_FRAME */
815 s->mv_type = MV_TYPE_16X16;
816 for(k=0;k<2;k++) {
817 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
818 s->last_mv[i][0][k]);
819 s->last_mv[i][0][k] = val;
820 s->last_mv[i][1][k] = val;
821 /* full_pel: only for mpeg1 */
822 if (s->full_pel[i])
823 val = val << 1;
824 s->mv[i][0][k] = val;
825 dprintf("mv%d: %d\n", k, val);
826 }
827 } else {
828 /* MT_16X8 */
829 s->mv_type = MV_TYPE_16X8;
830 for(j=0;j<2;j++) {
831 s->field_select[i][j] = get_bits1(&s->gb);
832 for(k=0;k<2;k++) {
833 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
834 s->last_mv[i][j][k]);
835 s->last_mv[i][j][k] = val;
836 s->mv[i][j][k] = val;
837 }
838 }
839 }
840 break;
841 case MT_FIELD:
842 if (s->picture_structure == PICT_FRAME) {
843 s->mv_type = MV_TYPE_FIELD;
844 for(j=0;j<2;j++) {
845 s->field_select[i][j] = get_bits1(&s->gb);
846 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
847 s->last_mv[i][j][0]);
848 s->last_mv[i][j][0] = val;
849 s->mv[i][j][0] = val;
850 dprintf("fmx=%d\n", val);
851 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
852 s->last_mv[i][j][1] >> 1);
853 s->last_mv[i][j][1] = val << 1;
854 s->mv[i][j][1] = val;
855 dprintf("fmy=%d\n", val);
856 }
857 } else {
858 s->mv_type = MV_TYPE_16X16;
859 s->field_select[i][0] = get_bits1(&s->gb);
860 for(k=0;k<2;k++) {
861 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
862 s->last_mv[i][0][k]);
863 s->last_mv[i][0][k] = val;
864 s->last_mv[i][1][k] = val;
865 s->mv[i][0][k] = val;
866 }
867 }
868 break;
869 case MT_DMV:
870 {
871 int dmx, dmy, mx, my, m;
872
873 mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
874 s->last_mv[i][0][0]);
875 s->last_mv[i][0][0] = mx;
876 s->last_mv[i][1][0] = mx;
877 dmx = get_dmv(s);
878 my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
879 s->last_mv[i][0][1] >> 1);
880 dmy = get_dmv(s);
881 s->mv_type = MV_TYPE_DMV;
882 /* XXX: totally broken */
883 if (s->picture_structure == PICT_FRAME) {
884 s->last_mv[i][0][1] = my << 1;
885 s->last_mv[i][1][1] = my << 1;
886
887 m = s->top_field_first ? 1 : 3;
888 /* top -> top pred */
889 s->mv[i][0][0] = mx;
890 s->mv[i][0][1] = my << 1;
891 s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
892 s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
893 m = 4 - m;
894 s->mv[i][2][0] = mx;
895 s->mv[i][2][1] = my << 1;
896 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
897 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
898 } else {
899 s->last_mv[i][0][1] = my;
900 s->last_mv[i][1][1] = my;
901 s->mv[i][0][0] = mx;
902 s->mv[i][0][1] = my;
903 s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
904 s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
905 /* + 2 * cur_field */;
906 }
907 }
908 break;
909 }
910 }
911 }
912 }
913
914 if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
915 skip_bits1(&s->gb); /* marker */
916 }
917
918 if (mb_type & MB_PAT) {
919 cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
920 if (cbp < 0){
921 fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
922 return -1;
923 }
924 cbp++;
925 }
926 dprintf("cbp=%x\n", cbp);
927
928 if (s->mpeg2) {
929 if (s->mb_intra) {
930 for(i=0;i<6;i++) {
931 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
932 return -1;
933 }
934 } else {
935 for(i=0;i<6;i++) {
936 if (cbp & 32) {
937 if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
938 return -1;
939 } else {
940 s->block_last_index[i] = -1;
941 }
942 cbp+=cbp;
943 }
944 }
945 } else {
946 if (s->mb_intra) {
947 for(i=0;i<6;i++) {
948 if (mpeg1_decode_block_intra(s, block[i], i) < 0)
949 return -1;
950 }
951 }else{
952 for(i=0;i<6;i++) {
953 if (cbp & 32) {
954 if (mpeg1_decode_block_inter(s, block[i], i) < 0)
955 return -1;
956 } else {
957 s->block_last_index[i] = -1;
958 }
959 cbp+=cbp;
960 }
961 }
962 }
963 return 0;
964 }
965
966 /* as h263, but only 17 codes */
967 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
968 {
969 int code, sign, val, m, l, shift;
970
971 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
972 if (code < 0) {
973 return 0xffff;
974 }
975 if (code == 0) {
976 return pred;
977 }
978 sign = get_bits1(&s->gb);
979 shift = fcode - 1;
980 val = (code - 1) << shift;
981 if (shift > 0)
982 val |= get_bits(&s->gb, shift);
983 val++;
984 if (sign)
985 val = -val;
986 val += pred;
987
988 /* modulo decoding */
989 l = (1 << shift) * 16;
990 m = 2 * l;
991 if (val < -l) {
992 val += m;
993 } else if (val >= l) {
994 val -= m;
995 }
996 return val;
997 }
998
999 static inline int decode_dc(MpegEncContext *s, int component)
1000 {
1001 int code, diff;
1002
1003 if (component == 0) {
1004 code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
1005 } else {
1006 code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
1007 }
1008 if (code < 0){
1009 fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
1010 return 0xffff;
1011 }
1012 if (code == 0) {
1013 diff = 0;
1014 } else {
1015 diff = get_bits(&s->gb, code);
1016 if ((diff & (1 << (code - 1))) == 0)
1017 diff = (-1 << code) | (diff + 1);
1018 }
1019 return diff;
1020 }
1021
1022 static inline int mpeg1_decode_block_intra(MpegEncContext *s,
1023 DCTELEM *block,
1024 int n)
1025 {
1026 int level, dc, diff, i, j, run;
1027 int component;
1028 RLTable *rl = &rl_mpeg1;
1029 UINT8 * const scantable= s->intra_scantable.permutated;
1030 const UINT16 *quant_matrix= s->intra_matrix;
1031 const int qscale= s->qscale;
1032
1033 /* DC coef */
1034 component = (n <= 3 ? 0 : n - 4 + 1);
1035 diff = decode_dc(s, component);
1036 if (diff >= 0xffff)
1037 return -1;
1038 dc = s->last_dc[component];
1039 dc += diff;
1040 s->last_dc[component] = dc;
1041 block[0] = dc<<3;
1042 dprintf("dc=%d diff=%d\n", dc, diff);
1043 i = 0;
1044 {
1045 OPEN_READER(re, &s->gb);
1046 /* now quantify & encode AC coefs */
1047 for(;;) {
1048 UPDATE_CACHE(re, &s->gb);
1049 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1050
1051 if(level == 127){
1052 break;
1053 } else if(level != 0) {
1054 i += run;
1055 j = scantable[i];
1056 level= (level*qscale*quant_matrix[j])>>3;
1057 level= (level-1)|1;
1058 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1059 LAST_SKIP_BITS(re, &s->gb, 1);
1060 } else {
1061 /* escape */
1062 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1063 UPDATE_CACHE(re, &s->gb);
1064 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1065 if (level == -128) {
1066 level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1067 } else if (level == 0) {
1068 level = SHOW_UBITS(re, &s->gb, 8) ; LAST_SKIP_BITS(re, &s->gb, 8);
1069 }
1070 i += run;
1071 j = scantable[i];
1072 if(level<0){
1073 level= -level;
1074 level= (level*qscale*quant_matrix[j])>>3;
1075 level= (level-1)|1;
1076 level= -level;
1077 }else{
1078 level= (level*qscale*quant_matrix[j])>>3;
1079 level= (level-1)|1;
1080 }
1081 }
1082 if (i > 63){
1083 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1084 return -1;
1085 }
1086
1087 block[j] = level;
1088 }
1089 CLOSE_READER(re, &s->gb);
1090 }
1091 s->block_last_index[n] = i;
1092 return 0;
1093 }
1094
1095 static inline int mpeg1_decode_block_inter(MpegEncContext *s,
1096 DCTELEM *block,
1097 int n)
1098 {
1099 int level, i, j, run;
1100 RLTable *rl = &rl_mpeg1;
1101 UINT8 * const scantable= s->intra_scantable.permutated;
1102 const UINT16 *quant_matrix= s->inter_matrix;
1103 const int qscale= s->qscale;
1104
1105 {
1106 int v;
1107 OPEN_READER(re, &s->gb);
1108 i = -1;
1109 /* special case for the first coef. no need to add a second vlc table */
1110 UPDATE_CACHE(re, &s->gb);
1111 v= SHOW_UBITS(re, &s->gb, 2);
1112 if (v & 2) {
1113 LAST_SKIP_BITS(re, &s->gb, 2);
1114 level= (3*qscale*quant_matrix[0])>>4;
1115 level= (level-1)|1;
1116 if(v&1)
1117 level= -level;
1118 block[0] = level;
1119 i++;
1120 }
1121
1122 /* now quantify & encode AC coefs */
1123 for(;;) {
1124 UPDATE_CACHE(re, &s->gb);
1125 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1126
1127 if(level == 127){
1128 break;
1129 } else if(level != 0) {
1130 i += run;
1131 j = scantable[i];
1132 level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1133 level= (level-1)|1;
1134 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1135 LAST_SKIP_BITS(re, &s->gb, 1);
1136 } else {
1137 /* escape */
1138 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1139 UPDATE_CACHE(re, &s->gb);
1140 level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
1141 if (level == -128) {
1142 level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
1143 } else if (level == 0) {
1144 level = SHOW_UBITS(re, &s->gb, 8) ; LAST_SKIP_BITS(re, &s->gb, 8);
1145 }
1146 i += run;
1147 j = scantable[i];
1148 if(level<0){
1149 level= -level;
1150 level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1151 level= (level-1)|1;
1152 level= -level;
1153 }else{
1154 level= ((level*2+1)*qscale*quant_matrix[j])>>4;
1155 level= (level-1)|1;
1156 }
1157 }
1158 if (i > 63){
1159 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1160 return -1;
1161 }
1162
1163 block[j] = level;
1164 }
1165 CLOSE_READER(re, &s->gb);
1166 }
1167 s->block_last_index[n] = i;
1168 return 0;
1169 }
1170
1171 /* Also does unquantization here, since I will never support mpeg2
1172 encoding */
1173 static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
1174 DCTELEM *block,
1175 int n)
1176 {
1177 int level, i, j, run;
1178 RLTable *rl = &rl_mpeg1;
1179 UINT8 * const scantable= s->intra_scantable.permutated;
1180 const UINT16 *quant_matrix;
1181 const int qscale= s->qscale;
1182 int mismatch;
1183
1184 mismatch = 1;
1185
1186 {
1187 int v;
1188 OPEN_READER(re, &s->gb);
1189 i = -1;
1190 if (n < 4)
1191 quant_matrix = s->inter_matrix;
1192 else
1193 quant_matrix = s->chroma_inter_matrix;
1194
1195 /* special case for the first coef. no need to add a second vlc table */
1196 UPDATE_CACHE(re, &s->gb);
1197 v= SHOW_UBITS(re, &s->gb, 2);
1198 if (v & 2) {
1199 LAST_SKIP_BITS(re, &s->gb, 2);
1200 level= (3*qscale*quant_matrix[0])>>5;
1201 if(v&1)
1202 level= -level;
1203 block[0] = level;
1204 mismatch ^= level;
1205 i++;
1206 }
1207
1208 /* now quantify & encode AC coefs */
1209 for(;;) {
1210 UPDATE_CACHE(re, &s->gb);
1211 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1212
1213 if(level == 127){
1214 break;
1215 } else if(level != 0) {
1216 i += run;
1217 j = scantable[i];
1218 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1219 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1220 LAST_SKIP_BITS(re, &s->gb, 1);
1221 } else {
1222 /* escape */
1223 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1224 UPDATE_CACHE(re, &s->gb);
1225 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1226
1227 i += run;
1228 j = scantable[i];
1229 if(level<0){
1230 level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
1231 level= -level;
1232 }else{
1233 level= ((level*2+1)*qscale*quant_matrix[j])>>5;
1234 }
1235 }
1236 if (i > 63){
1237 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1238 return -1;
1239 }
1240
1241 mismatch ^= level;
1242 block[j] = level;
1243 }
1244 CLOSE_READER(re, &s->gb);
1245 }
1246 block[63] ^= (mismatch & 1);
1247
1248 s->block_last_index[n] = i;
1249 return 0;
1250 }
1251
1252 static inline int mpeg2_decode_block_intra(MpegEncContext *s,
1253 DCTELEM *block,
1254 int n)
1255 {
1256 int level, dc, diff, i, j, run;
1257 int component;
1258 RLTable *rl;
1259 UINT8 * const scantable= s->intra_scantable.permutated;
1260 const UINT16 *quant_matrix;
1261 const int qscale= s->qscale;
1262 int mismatch;
1263
1264 /* DC coef */
1265 if (n < 4){
1266 quant_matrix = s->intra_matrix;
1267 component = 0;
1268 }else{
1269 quant_matrix = s->chroma_intra_matrix;
1270 component = n - 3;
1271 }
1272 diff = decode_dc(s, component);
1273 if (diff >= 0xffff)
1274 return -1;
1275 dc = s->last_dc[component];
1276 dc += diff;
1277 s->last_dc[component] = dc;
1278 block[0] = dc << (3 - s->intra_dc_precision);
1279 dprintf("dc=%d\n", block[0]);
1280 mismatch = block[0] ^ 1;
1281 i = 0;
1282 if (s->intra_vlc_format)
1283 rl = &rl_mpeg2;
1284 else
1285 rl = &rl_mpeg1;
1286
1287 {
1288 OPEN_READER(re, &s->gb);
1289 /* now quantify & encode AC coefs */
1290 for(;;) {
1291 UPDATE_CACHE(re, &s->gb);
1292 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
1293
1294 if(level == 127){
1295 break;
1296 } else if(level != 0) {
1297 i += run;
1298 j = scantable[i];
1299 level= (level*qscale*quant_matrix[j])>>4;
1300 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1301 LAST_SKIP_BITS(re, &s->gb, 1);
1302 } else {
1303 /* escape */
1304 run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
1305 UPDATE_CACHE(re, &s->gb);
1306 level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
1307 i += run;
1308 j = scantable[i];
1309 if(level<0){
1310 level= (-level*qscale*quant_matrix[j])>>4;
1311 level= -level;
1312 }else{
1313 level= (level*qscale*quant_matrix[j])>>4;
1314 }
1315 }
1316 if (i > 63){
1317 fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1318 return -1;
1319 }
1320
1321 mismatch^= level;
1322 block[j] = level;
1323 }
1324 CLOSE_READER(re, &s->gb);
1325 }
1326 block[63]^= mismatch&1;
1327
1328 s->block_last_index[n] = i;
1329 return 0;
1330 }
1331
1332 /* compressed picture size */
1333 #define PICTURE_BUFFER_SIZE 100000
1334
1335 typedef struct Mpeg1Context {
1336 MpegEncContext mpeg_enc_ctx;
1337 UINT32 header_state;
1338 int start_code; /* current start code */
1339 UINT8 buffer[PICTURE_BUFFER_SIZE];
1340 UINT8 *buf_ptr;
1341 int buffer_size;
1342 int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1343 int repeat_field; /* true if we must repeat the field */
1344 } Mpeg1Context;
1345
1346 static int mpeg_decode_init(AVCodecContext *avctx)
1347 {
1348 Mpeg1Context *s = avctx->priv_data;
1349
1350 s->mpeg_enc_ctx.flags= avctx->flags;
1351 common_init(&s->mpeg_enc_ctx);
1352 init_vlcs(&s->mpeg_enc_ctx);
1353
1354 s->header_state = 0xff;
1355 s->mpeg_enc_ctx_allocated = 0;
1356 s->buffer_size = PICTURE_BUFFER_SIZE;
1357 s->start_code = -1;
1358 s->buf_ptr = s->buffer;
1359 s->mpeg_enc_ctx.picture_number = 0;
1360 s->repeat_field = 0;
1361 s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1362 avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1363 return 0;
1364 }
1365
1366 /* return the 8 bit start code value and update the search
1367 state. Return -1 if no start code found */
1368 static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end,
1369 UINT32 *header_state)
1370 {
1371 UINT8 *buf_ptr;
1372 unsigned int state, v;
1373 int val;
1374
1375 state = *header_state;
1376 buf_ptr = *pbuf_ptr;
1377 while (buf_ptr < buf_end) {
1378 v = *buf_ptr++;
1379 if (state == 0x000001) {
1380 state = ((state << 8) | v) & 0xffffff;
1381 val = state;
1382 goto found;
1383 }
1384 state = ((state << 8) | v) & 0xffffff;
1385 }
1386 val = -1;
1387 found:
1388 *pbuf_ptr = buf_ptr;
1389 *header_state = state;
1390 return val;
1391 }
1392
1393 static int mpeg1_decode_picture(AVCodecContext *avctx,
1394 UINT8 *buf, int buf_size)
1395 {
1396 Mpeg1Context *s1 = avctx->priv_data;
1397 MpegEncContext *s = &s1->mpeg_enc_ctx;
1398 int ref, f_code;
1399
1400 init_get_bits(&s->gb, buf, buf_size);
1401
1402 ref = get_bits(&s->gb, 10); /* temporal ref */
1403 s->pict_type = get_bits(&s->gb, 3);
1404 dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1405
1406 avctx->pict_type= s->pict_type;
1407 avctx->key_frame= s->pict_type == I_TYPE;
1408
1409 skip_bits(&s->gb, 16);
1410 if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1411 s->full_pel[0] = get_bits1(&s->gb);
1412 f_code = get_bits(&s->gb, 3);
1413 if (f_code == 0)
1414 return -1;
1415 s->mpeg_f_code[0][0] = f_code;
1416 s->mpeg_f_code[0][1] = f_code;
1417 }
1418 if (s->pict_type == B_TYPE) {
1419 s->full_pel[1] = get_bits1(&s->gb);
1420 f_code = get_bits(&s->gb, 3);
1421 if (f_code == 0)
1422 return -1;
1423 s->mpeg_f_code[1][0] = f_code;
1424 s->mpeg_f_code[1][1] = f_code;
1425 }
1426 s->y_dc_scale = 8;
1427 s->c_dc_scale = 8;
1428 s->first_slice = 1;
1429 return 0;
1430 }
1431
1432 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1433 {
1434 int horiz_size_ext, vert_size_ext;
1435 int bit_rate_ext, vbv_buf_ext, low_delay;
1436 int frame_rate_ext_n, frame_rate_ext_d;
1437
1438 skip_bits(&s->gb, 8); /* profil and level */
1439 s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1440 skip_bits(&s->gb, 2); /* chroma_format */
1441 horiz_size_ext = get_bits(&s->gb, 2);
1442 vert_size_ext = get_bits(&s->gb, 2);
1443 s->width |= (horiz_size_ext << 12);
1444 s->height |= (vert_size_ext << 12);
1445 bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */
1446 s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1447 skip_bits1(&s->gb); /* marker */
1448 vbv_buf_ext = get_bits(&s->gb, 8);
1449 low_delay = get_bits1(&s->gb);
1450 frame_rate_ext_n = get_bits(&s->gb, 2);
1451 frame_rate_ext_d = get_bits(&s->gb, 5);
1452 if (frame_rate_ext_d >= 1)
1453 s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1454 dprintf("sequence extension\n");
1455 s->mpeg2 = 1;
1456 s->avctx->sub_id = 2; /* indicates mpeg2 found */
1457 }
1458
1459 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1460 {
1461 int i, v, j;
1462
1463 dprintf("matrix extension\n");
1464
1465 if (get_bits1(&s->gb)) {
1466 for(i=0;i<64;i++) {
1467 v = get_bits(&s->gb, 8);
1468 j= s->idct_permutation[ ff_zigzag_direct[i] ];
1469 s->intra_matrix[j] = v;
1470 s->chroma_intra_matrix[j] = v;
1471 }
1472 }
1473 if (get_bits1(&s->gb)) {
1474 for(i=0;i<64;i++) {
1475 v = get_bits(&s->gb, 8);
1476 j= s->idct_permutation[ ff_zigzag_direct[i] ];
1477 s->inter_matrix[j] = v;
1478 s->chroma_inter_matrix[j] = v;
1479 }
1480 }
1481 if (get_bits1(&s->gb)) {
1482 for(i=0;i<64;i++) {
1483 v = get_bits(&s->gb, 8);
1484 j= s->idct_permutation[ ff_zigzag_direct[i] ];
1485 s->chroma_intra_matrix[j] = v;
1486 }
1487 }
1488 if (get_bits1(&s->gb)) {
1489 for(i=0;i<64;i++) {
1490 v = get_bits(&s->gb, 8);
1491 j= s->idct_permutation[ ff_zigzag_direct[i] ];
1492 s->chroma_inter_matrix[j] = v;
1493 }
1494 }
1495 }
1496
1497 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1498 {
1499 s->full_pel[0] = s->full_pel[1] = 0;
1500 s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1501 s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1502 s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1503 s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1504 s->intra_dc_precision = get_bits(&s->gb, 2);
1505 s->picture_structure = get_bits(&s->gb, 2);
1506 s->top_field_first = get_bits1(&s->gb);
1507 s->frame_pred_frame_dct = get_bits1(&s->gb);
1508 s->concealment_motion_vectors = get_bits1(&s->gb);
1509 s->q_scale_type = get_bits1(&s->gb);
1510 s->intra_vlc_format = get_bits1(&s->gb);
1511 s->alternate_scan = get_bits1(&s->gb);
1512 s->repeat_first_field = get_bits1(&s->gb);
1513 s->chroma_420_type = get_bits1(&s->gb);
1514 s->progressive_frame = get_bits1(&s->gb);
1515
1516 if(s->alternate_scan){
1517 ff_init_scantable(s, &s->inter_scantable , ff_alternate_vertical_scan);
1518 ff_init_scantable(s, &s->intra_scantable , ff_alternate_vertical_scan);
1519 ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_vertical_scan);
1520 ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
1521 }else{
1522 ff_init_scantable(s, &s->inter_scantable , ff_zigzag_direct);
1523 ff_init_scantable(s, &s->intra_scantable , ff_zigzag_direct);
1524 ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_horizontal_scan);
1525 ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
1526 }
1527
1528 /* composite display not parsed */
1529 dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1530 dprintf("picture_structure=%d\n", s->picture_structure);
1531 dprintf("top field first=%d\n", s->top_field_first);
1532 dprintf("repeat first field=%d\n", s->repeat_first_field);
1533 dprintf("conceal=%d\n", s->concealment_motion_vectors);
1534 dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1535 dprintf("alternate_scan=%d\n", s->alternate_scan);
1536 dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1537 dprintf("progressive_frame=%d\n", s->progressive_frame);
1538 }
1539
1540 static void mpeg_decode_extension(AVCodecContext *avctx,
1541 UINT8 *buf, int buf_size)
1542 {
1543 Mpeg1Context *s1 = avctx->priv_data;
1544 MpegEncContext *s = &s1->mpeg_enc_ctx;
1545 int ext_type;
1546
1547 init_get_bits(&s->gb, buf, buf_size);
1548
1549 ext_type = get_bits(&s->gb, 4);
1550 switch(ext_type) {
1551 case 0x1:
1552 /* sequence ext */
1553 mpeg_decode_sequence_extension(s);
1554 break;
1555 case 0x3:
1556 /* quant matrix extension */
1557 mpeg_decode_quant_matrix_extension(s);
1558 break;
1559 case 0x8:
1560 /* picture extension */
1561 mpeg_decode_picture_coding_extension(s);
1562 break;
1563 }
1564 }
1565
1566 #define DECODE_SLICE_FATAL_ERROR -2
1567 #define DECODE_SLICE_ERROR -1
1568 #define DECODE_SLICE_OK 0
1569 #define DECODE_SLICE_EOP 1
1570
1571 /**
1572 * decodes a slice.
1573 * @return DECODE_SLICE_FATAL_ERROR if a non recoverable error occured<br>
1574 * DECODE_SLICE_ERROR if the slice is damaged<br>
1575 * DECODE_SLICE_OK if this slice is ok<br>
1576 * DECODE_SLICE_EOP if the end of the picture is reached
1577 */
1578 static int mpeg_decode_slice(AVCodecContext *avctx,
1579 AVPicture *pict,
1580 int start_code,
1581 UINT8 *buf, int buf_size)
1582 {
1583 Mpeg1Context *s1 = avctx->priv_data;
1584 MpegEncContext *s = &s1->mpeg_enc_ctx;
1585 int ret;
1586
1587 start_code = (start_code - 1) & 0xff;
1588 if (start_code >= s->mb_height){
1589 fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);
1590 return DECODE_SLICE_ERROR;
1591 }
1592 s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1593 s->last_dc[1] = s->last_dc[0];
1594 s->last_dc[2] = s->last_dc[0];
1595 memset(s->last_mv, 0, sizeof(s->last_mv));
1596 /* start frame decoding */
1597 if (s->first_slice) {
1598 s->first_slice = 0;
1599 if(MPV_frame_start(s, avctx) < 0)
1600 return DECODE_SLICE_FATAL_ERROR;
1601 }
1602
1603 init_get_bits(&s->gb, buf, buf_size);
1604
1605 s->qscale = get_qscale(s);
1606 /* extra slice info */
1607 while (get_bits1(&s->gb) != 0) {
1608 skip_bits(&s->gb, 8);
1609 }
1610
1611 s->mb_x=0;
1612 for(;;) {
1613 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1614 if (code < 0)
1615 return -1; /* error = end of slice, but empty slice is bad or?*/
1616 if (code >= 33) {
1617 if (code == 33) {
1618 s->mb_x += 33;
1619 }
1620 /* otherwise, stuffing, nothing to do */
1621 } else {
1622 s->mb_x += code;
1623 break;
1624 }
1625 }
1626 s->mb_y = start_code;
1627 s->mb_incr= 1;
1628
1629 for(;;) {
1630 s->dsp.clear_blocks(s->block[0]);
1631
1632 ret = mpeg_decode_mb(s, s->block);
1633 dprintf("ret=%d\n", ret);
1634 if (ret < 0)
1635 return -1;
1636
1637 MPV_decode_mb(s, s->block);
1638
1639 if (++s->mb_x >= s->mb_width) {
1640 ff_draw_horiz_band(s);
1641
1642 s->mb_x = 0;
1643 s->mb_y++;
1644 PRINT_QP("%s", "\n");
1645 }
1646 PRINT_QP("%2d", s->qscale);
1647
1648 /* skip mb handling */
1649 if (s->mb_incr == 0) {
1650 /* read again increment */
1651 s->mb_incr = 1;
1652 for(;;) {
1653 int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
1654 if (code < 0)
1655 goto eos; /* error = end of slice */
1656 if (code >= 33) {
1657 if (code == 33) {
1658 s->mb_incr += 33;
1659 }
1660 /* otherwise, stuffing, nothing to do */
1661 } else {
1662 s->mb_incr += code;
1663 break;
1664 }
1665 }
1666 }
1667 if(s->mb_y >= s->mb_height){
1668 fprintf(stderr, "slice too long\n");
1669 return DECODE_SLICE_ERROR;
1670 }
1671 }
1672 eos: //end of slice
1673
1674 emms_c();
1675
1676 /* end of slice reached */
1677 if (/*s->mb_x == 0 &&*/
1678 s->mb_y == s->mb_height) {
1679 /* end of image */
1680 UINT8 **picture;
1681
1682 MPV_frame_end(s);
1683
1684 if (s->pict_type == B_TYPE) {
1685 picture = s->current_picture;
1686 avctx->quality = s->qscale;
1687 } else {
1688 /* latency of 1 frame for I and P frames */
1689 /* XXX: use another variable than picture_number */
1690 if (s->picture_number == 0) {
1691 picture = NULL;
1692 } else {
1693 picture = s->last_picture;
1694 avctx->quality = s->last_qscale;
1695 }
1696 s->last_qscale = s->qscale;
1697 s->picture_number++;
1698 }
1699 if(s->mpeg2)
1700 avctx->quality>>=1;
1701 if (picture) {
1702 pict->data[0] = picture[0];
1703 pict->data[1] = picture[1];
1704 pict->data[2] = picture[2];
1705 pict->linesize[0] = s->linesize;
1706 pict->linesize[1] = s->uvlinesize;
1707 pict->linesize[2] = s->uvlinesize;
1708 return DECODE_SLICE_EOP;
1709 } else {
1710 return DECODE_SLICE_OK;
1711 }
1712 } else {
1713 return DECODE_SLICE_OK;
1714 }
1715 }
1716
1717 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1718 UINT8 *buf, int buf_size)
1719 {
1720 Mpeg1Context *s1 = avctx->priv_data;
1721 MpegEncContext *s = &s1->mpeg_enc_ctx;
1722 int width, height, i, v, j;
1723
1724 init_get_bits(&s->gb, buf, buf_size);
1725
1726 width = get_bits(&s->gb, 12);
1727 height = get_bits(&s->gb, 12);
1728 skip_bits(&s->gb, 4);
1729 s->frame_rate_index = get_bits(&s->gb, 4);
1730 if (s->frame_rate_index == 0)
1731 return -1;
1732 s->bit_rate = get_bits(&s->gb, 18) * 400;
1733 if (get_bits1(&s->gb) == 0) /* marker */
1734 return -1;
1735 if (width <= 0 || height <= 0 ||
1736 (width % 2) != 0 || (height % 2) != 0)
1737 return -1;
1738 if (width != s->width ||
1739 height != s->height) {
1740 /* start new mpeg1 context decoding */
1741 s->out_format = FMT_MPEG1;
1742 if (s1->mpeg_enc_ctx_allocated) {
1743 MPV_common_end(s);
1744 }
1745 s->width = width;
1746 s->height = height;
1747 avctx->has_b_frames= s->has_b_frames = 1;
1748 s->avctx = avctx;
1749 avctx->width = width;
1750 avctx->height = height;
1751 if (s->frame_rate_index >= 9) {
1752 /* at least give a valid frame rate (some old mpeg1 have this) */
1753 avctx->frame_rate = 25 * FRAME_RATE_BASE;
1754 } else {
1755 avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1756 }
1757 s->frame_rate = avctx->frame_rate;
1758 avctx->bit_rate = s->bit_rate;
1759
1760 if (MPV_common_init(s) < 0)
1761 return -1;
1762 s1->mpeg_enc_ctx_allocated = 1;
1763 }
1764
1765 skip_bits(&s->gb, 10); /* vbv_buffer_size */
1766 skip_bits(&s->gb, 1);
1767
1768 /* get matrix */
1769 if (get_bits1(&s->gb)) {
1770 for(i=0;i<64;i++) {
1771 v = get_bits(&s->gb, 8);
1772 j = s->intra_scantable.permutated[i];
1773 s->intra_matrix[j] = v;
1774 s->chroma_intra_matrix[j] = v;
1775 }
1776 #ifdef DEBUG
1777 dprintf("intra matrix present\n");
1778 for(i=0;i<64;i++)
1779 dprintf(" %d", s->intra_matrix[s->intra_scantable.permutated[i]]);
1780 printf("\n");
1781 #endif
1782 } else {
1783 for(i=0;i<64;i++) {
1784 int j= s->idct_permutation[i];
1785 v = ff_mpeg1_default_intra_matrix[i];
1786 s->intra_matrix[j] = v;
1787 s->chroma_intra_matrix[j] = v;
1788 }
1789 }
1790 if (get_bits1(&s->gb)) {
1791 for(i=0;i<64;i++) {
1792 v = get_bits(&s->gb, 8);
1793 j = s->intra_scantable.permutated[i];
1794 s->inter_matrix[j] = v;
1795 s->chroma_inter_matrix[j] = v;
1796 }
1797 #ifdef DEBUG
1798 dprintf("non intra matrix present\n");
1799 for(i=0;i<64;i++)
1800 dprintf(" %d", s->inter_matrix[s->intra_scantable.permutated[i]]);
1801 printf("\n");
1802 #endif
1803 } else {
1804 for(i=0;i<64;i++) {
1805 int j= s->idct_permutation[i];
1806 v = ff_mpeg1_default_non_intra_matrix[i];
1807 s->inter_matrix[j] = v;
1808 s->chroma_inter_matrix[j] = v;
1809 }
1810 }
1811
1812 /* we set mpeg2 parameters so that it emulates mpeg1 */
1813 s->progressive_sequence = 1;
1814 s->progressive_frame = 1;
1815 s->picture_structure = PICT_FRAME;
1816 s->frame_pred_frame_dct = 1;
1817 s->mpeg2 = 0;
1818 avctx->sub_id = 1; /* indicates mpeg1 */
1819 return 0;
1820 }
1821
1822 /* handle buffering and image synchronisation */
1823 static int mpeg_decode_frame(AVCodecContext *avctx,
1824 void *data, int *data_size,
1825 UINT8 *buf, int buf_size)
1826 {
1827 Mpeg1Context *s = avctx->priv_data;
1828 UINT8 *buf_end, *buf_ptr, *buf_start;
1829 int len, start_code_found, ret, code, start_code, input_size;
1830 AVPicture *picture = data;
1831 MpegEncContext *s2 = &s->mpeg_enc_ctx;
1832
1833 dprintf("fill_buffer\n");
1834
1835 *data_size = 0;
1836
1837 /* special case for last picture */
1838 if (buf_size == 0) {
1839 if (s2->picture_number > 0) {
1840 picture->data[0] = s2->next_picture[0];
1841 picture->data[1] = s2->next_picture[1];
1842 picture->data[2] = s2->next_picture[2];
1843 picture->linesize[0] = s2->linesize;
1844 picture->linesize[1] = s2->uvlinesize;
1845 picture->linesize[2] = s2->uvlinesize;
1846 *data_size = sizeof(AVPicture);
1847 }
1848 return 0;
1849 }
1850
1851 buf_ptr = buf;
1852 buf_end = buf + buf_size;
1853
1854 #if 0
1855 if (s->repeat_field % 2 == 1) {
1856 s->repeat_field++;
1857 //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1858 // s2->picture_number, s->repeat_field);
1859 if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
1860 *data_size = sizeof(AVPicture);
1861 goto the_end;
1862 }
1863 }
1864 #endif
1865 while (buf_ptr < buf_end) {
1866 buf_start = buf_ptr;
1867 /* find start next code */
1868 code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1869 if (code >= 0) {
1870 start_code_found = 1;
1871 } else {
1872 start_code_found = 0;
1873 }
1874 /* copy to buffer */
1875 len = buf_ptr - buf_start;
1876 if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1877 /* data too big : flush */
1878 s->buf_ptr = s->buffer;
1879 if (start_code_found)
1880 s->start_code = code;
1881 } else {
1882 memcpy(s->buf_ptr, buf_start, len);
1883 s->buf_ptr += len;
1884 if( (!(s2->flags&CODEC_FLAG_TRUNCATED)) && (!start_code_found)
1885 && s->buf_ptr+4<s->buffer+s->buffer_size){
1886 start_code_found= 1;
1887 code= 0x1FF;
1888 s->header_state=0xFF;
1889 s->buf_ptr[0]=0;
1890 s->buf_ptr[1]=0;
1891 s->buf_ptr[2]=1;
1892 s->buf_ptr[3]=0xFF;
1893 s->buf_ptr+=4;
1894 }
1895 if (start_code_found) {
1896 /* prepare data for next start code */
1897 input_size = s->buf_ptr - s->buffer;
1898 start_code = s->start_code;
1899 s->buf_ptr = s->buffer;
1900 s->start_code = code;
1901 switch(start_code) {
1902 case SEQ_START_CODE:
1903 mpeg1_decode_sequence(avctx, s->buffer,
1904 input_size);
1905 break;
1906
1907 case PICTURE_START_CODE:
1908 /* we have a complete image : we try to decompress it */
1909 mpeg1_decode_picture(avctx,
1910 s->buffer, input_size);
1911 break;
1912 case EXT_START_CODE:
1913 mpeg_decode_extension(avctx,
1914 s->buffer, input_size);
1915 break;
1916 default:
1917 if (start_code >= SLICE_MIN_START_CODE &&
1918 start_code <= SLICE_MAX_START_CODE && s2->avctx->hurry_up<5) {
1919 ret = mpeg_decode_slice(avctx, picture,
1920 start_code, s->buffer, input_size);
1921 if (ret == DECODE_SLICE_EOP) {
1922 /* got a picture: exit */
1923 /* first check if we must repeat the frame */
1924 avctx->repeat_pict = 0;
1925 #if 0
1926 if (s2->progressive_frame && s2->repeat_first_field) {
1927 //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1928 //s2->repeat_first_field = 0;
1929 //s2->progressive_frame = 0;
1930 if (++s->repeat_field > 2)
1931 s->repeat_field = 0;
1932 avctx->repeat_pict = 1;
1933 }
1934 #endif
1935 if (s2->repeat_first_field) {
1936 if (s2->progressive_sequence) {
1937 if (s2->top_field_first)
1938 avctx->repeat_pict = 4;
1939 else
1940 avctx->repeat_pict = 2;
1941 } else if (s2->progressive_frame) {
1942 avctx->repeat_pict = 1;
1943 }
1944 }
1945 *data_size = sizeof(AVPicture);
1946 goto the_end;
1947 }else if(ret<0){
1948 printf("Error while decoding slice\n");
1949 if(ret==DECODE_SLICE_FATAL_ERROR) return -1;
1950 }
1951 }
1952 break;
1953 }
1954 }
1955 }
1956 }
1957 the_end:
1958 return buf_ptr - buf;
1959 }
1960
1961 static int mpeg_decode_end(AVCodecContext *avctx)
1962 {
1963 Mpeg1Context *s = avctx->priv_data;
1964
1965 if (s->mpeg_enc_ctx_allocated)
1966 MPV_common_end(&s->mpeg_enc_ctx);
1967 return 0;
1968 }
1969
1970 AVCodec mpeg_decoder = {
1971 "mpegvideo",
1972 CODEC_TYPE_VIDEO,
1973 CODEC_ID_MPEG1VIDEO,
1974 sizeof(Mpeg1Context),
1975 mpeg_decode_init,
1976 NULL,
1977 mpeg_decode_end,
1978 mpeg_decode_frame,
1979 CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
1980 };