projects / libav.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
fixed one mpeg decoder memory leak
[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 /* Start codes. */
27 #define SEQ_END_CODE 0x000001b7
28 #define SEQ_START_CODE 0x000001b3
29 #define GOP_START_CODE 0x000001b8
30 #define PICTURE_START_CODE 0x00000100
31 #define SLICE_MIN_START_CODE 0x00000101
32 #define SLICE_MAX_START_CODE 0x000001af
33 #define EXT_START_CODE 0x000001b5
34 #define USER_START_CODE 0x000001b2
35
36 static void mpeg1_encode_block(MpegEncContext *s,
37 DCTELEM *block,
38 int component);
39 static void mpeg1_encode_motion(MpegEncContext *s, int val);
40 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
41 static int mpeg1_decode_block(MpegEncContext *s,
42 DCTELEM *block,
43 int n);
44 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
45 DCTELEM *block,
46 int n);
47 static int mpeg2_decode_block_intra(MpegEncContext *s,
48 DCTELEM *block,
49 int n);
50 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
51
52 static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
53 static UINT8 fcode_tab[MAX_MV*2+1];
54
55 static void put_header(MpegEncContext *s, int header)
56 {
57 align_put_bits(&s->pb);
58 put_bits(&s->pb, 16, header>>16);
59 put_bits(&s->pb, 16, header&0xFFFF);
60 }
61
62 /* put sequence header if needed */
63 static void mpeg1_encode_sequence_header(MpegEncContext *s)
64 {
65 unsigned int vbv_buffer_size;
66 unsigned int fps, v;
67 int n;
68 UINT64 time_code;
69
70 if (s->picture_in_gop_number == 0) {
71 /* mpeg1 header repeated every gop */
72 put_header(s, SEQ_START_CODE);
73
74 /* search closest frame rate */
75 {
76 int i, dmin, d;
77 s->frame_rate_index = 0;
78 dmin = 0x7fffffff;
79 for(i=1;i<9;i++) {
80 d = abs(s->frame_rate - frame_rate_tab[i]);
81 if (d < dmin) {
82 dmin = d;
83 s->frame_rate_index = i;
84 }
85 }
86 }
87
88 put_bits(&s->pb, 12, s->width);
89 put_bits(&s->pb, 12, s->height);
90 put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
91 put_bits(&s->pb, 4, s->frame_rate_index);
92 v = s->bit_rate / 400;
93 if (v > 0x3ffff)
94 v = 0x3ffff;
95 put_bits(&s->pb, 18, v);
96 put_bits(&s->pb, 1, 1); /* marker */
97 /* vbv buffer size: slightly greater than an I frame. We add
98 some margin just in case */
99 vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
100 put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
101 put_bits(&s->pb, 1, 1); /* constrained parameter flag */
102 put_bits(&s->pb, 1, 0); /* no custom intra matrix */
103 put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
104
105 put_header(s, GOP_START_CODE);
106 put_bits(&s->pb, 1, 0); /* do drop frame */
107 /* time code : we must convert from the real frame rate to a
108 fake mpeg frame rate in case of low frame rate */
109 fps = frame_rate_tab[s->frame_rate_index];
110 time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
111 s->gop_picture_number = s->fake_picture_number;
112 put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
113 put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
114 put_bits(&s->pb, 1, 1);
115 put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
116 put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
117 put_bits(&s->pb, 1, 1); /* closed gop */
118 put_bits(&s->pb, 1, 0); /* broken link */
119 }
120
121 if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
122 /* insert empty P pictures to slow down to the desired
123 frame rate. Each fake pictures takes about 20 bytes */
124 fps = frame_rate_tab[s->frame_rate_index];
125 n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
126 while (s->fake_picture_number < n) {
127 mpeg1_skip_picture(s, s->fake_picture_number -
128 s->gop_picture_number);
129 s->fake_picture_number++;
130 }
131
132 }
133 }
134
135
136 /* insert a fake P picture */
137 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
138 {
139 unsigned int mb_incr;
140
141 /* mpeg1 picture header */
142 put_header(s, PICTURE_START_CODE);
143 /* temporal reference */
144 put_bits(&s->pb, 10, pict_num & 0x3ff);
145
146 put_bits(&s->pb, 3, P_TYPE);
147 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
148
149 put_bits(&s->pb, 1, 1); /* integer coordinates */
150 put_bits(&s->pb, 3, 1); /* forward_f_code */
151
152 put_bits(&s->pb, 1, 0); /* extra bit picture */
153
154 /* only one slice */
155 put_header(s, SLICE_MIN_START_CODE);
156 put_bits(&s->pb, 5, 1); /* quantizer scale */
157 put_bits(&s->pb, 1, 0); /* slice extra information */
158
159 mb_incr = 1;
160 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
161 mbAddrIncrTable[mb_incr - 1][0]);
162
163 /* empty macroblock */
164 put_bits(&s->pb, 3, 1); /* motion only */
165
166 /* zero motion x & y */
167 put_bits(&s->pb, 1, 1);
168 put_bits(&s->pb, 1, 1);
169
170 /* output a number of empty slice */
171 mb_incr = s->mb_width * s->mb_height - 1;
172 while (mb_incr > 33) {
173 put_bits(&s->pb, 11, 0x008);
174 mb_incr -= 33;
175 }
176 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
177 mbAddrIncrTable[mb_incr - 1][0]);
178
179 /* empty macroblock */
180 put_bits(&s->pb, 3, 1); /* motion only */
181
182 /* zero motion x & y */
183 put_bits(&s->pb, 1, 1);
184 put_bits(&s->pb, 1, 1);
185 }
186
187 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
188 {
189 static int done=0;
190
191 if (!done) {
192 int i;
193 done = 1;
194 init_rl(&rl_mpeg1);
195
196 for(i=0; i<64; i++)
197 {
198 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
199 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
200 }
201
202 /* build unified dc encoding tables */
203 for(i=-255; i<256; i++)
204 {
205 int adiff, index;
206 int bits, code;
207 int diff=i;
208
209 adiff = ABS(diff);
210 if(diff<0) diff--;
211 index = vlc_dc_table[adiff];
212
213 bits= vlc_dc_lum_bits[index] + index;
214 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
215 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
216
217 bits= vlc_dc_chroma_bits[index] + index;
218 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
219 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
220 }
221 }
222 mpeg1_encode_sequence_header(s);
223
224 /* mpeg1 picture header */
225 put_header(s, PICTURE_START_CODE);
226 /* temporal reference */
227 put_bits(&s->pb, 10, (s->fake_picture_number -
228 s->gop_picture_number) & 0x3ff);
229 s->fake_picture_number++;
230
231 put_bits(&s->pb, 3, s->pict_type);
232 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
233
234 if (s->pict_type == P_TYPE) {
235 put_bits(&s->pb, 1, 0); /* half pel coordinates */
236 put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
237 }
238
239 put_bits(&s->pb, 1, 0); /* extra bit picture */
240
241 /* only one slice */
242 put_header(s, SLICE_MIN_START_CODE);
243 put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
244 put_bits(&s->pb, 1, 0); /* slice extra information */
245 }
246
247 void mpeg1_encode_mb(MpegEncContext *s,
248 DCTELEM block[6][64],
249 int motion_x, int motion_y)
250 {
251 int mb_incr, i, cbp, mb_x, mb_y;
252
253 mb_x = s->mb_x;
254 mb_y = s->mb_y;
255
256 /* compute cbp */
257 cbp = 0;
258 for(i=0;i<6;i++) {
259 if (s->block_last_index[i] >= 0)
260 cbp |= 1 << (5 - i);
261 }
262
263 /* skip macroblock, except if first or last macroblock of a slice */
264 if ((cbp | motion_x | motion_y) == 0 &&
265 (!((mb_x | mb_y) == 0 ||
266 (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
267 s->mb_incr++;
268 } else {
269 /* output mb incr */
270 mb_incr = s->mb_incr;
271
272 while (mb_incr > 33) {
273 put_bits(&s->pb, 11, 0x008);
274 mb_incr -= 33;
275 }
276 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
277 mbAddrIncrTable[mb_incr - 1][0]);
278
279 if (s->pict_type == I_TYPE) {
280 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
281 } else {
282 if (s->mb_intra) {
283 put_bits(&s->pb, 5, 0x03);
284 } else {
285 if (cbp != 0) {
286 if (motion_x == 0 && motion_y == 0) {
287 put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
288 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
289 } else {
290 put_bits(&s->pb, 1, 1); /* motion + cbp */
291 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
292 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
293 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
294 }
295 } else {
296 put_bits(&s->pb, 3, 1); /* motion only */
297 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
298 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
299 }
300 }
301 }
302 for(i=0;i<6;i++) {
303 if (cbp & (1 << (5 - i))) {
304 mpeg1_encode_block(s, block[i], i);
305 }
306 }
307 s->mb_incr = 1;
308 }
309 s->last_mv[0][0][0] = motion_x;
310 s->last_mv[0][0][1] = motion_y;
311 }
312
313 static void mpeg1_encode_motion(MpegEncContext *s, int val)
314 {
315 int code, bit_size, l, m, bits, range, sign;
316
317 if (val == 0) {
318 /* zero vector */
319 code = 0;
320 put_bits(&s->pb,
321 mbMotionVectorTable[0][1],
322 mbMotionVectorTable[0][0]);
323 } else {
324 bit_size = s->f_code - 1;
325 range = 1 << bit_size;
326 /* modulo encoding */
327 l = 16 * range;
328 m = 2 * l;
329 if (val < -l) {
330 val += m;
331 } else if (val >= l) {
332 val -= m;
333 }
334
335 if (val >= 0) {
336 val--;
337 code = (val >> bit_size) + 1;
338 bits = val & (range - 1);
339 sign = 0;
340 } else {
341 val = -val;
342 val--;
343 code = (val >> bit_size) + 1;
344 bits = val & (range - 1);
345 sign = 1;
346 }
347 put_bits(&s->pb,
348 mbMotionVectorTable[code][1],
349 mbMotionVectorTable[code][0]);
350 put_bits(&s->pb, 1, sign);
351 if (bit_size > 0) {
352 put_bits(&s->pb, bit_size, bits);
353 }
354 }
355 }
356
357 void mpeg1_encode_init(MpegEncContext *s)
358 {
359 static int done=0;
360 if(!done){
361 int f_code;
362 int mv;
363
364 done=1;
365 for(f_code=1; f_code<=MAX_FCODE; f_code++){
366 for(mv=-MAX_MV; mv<=MAX_MV; mv++){
367 int len;
368
369 if(mv==0) len= mbMotionVectorTable[0][1];
370 else{
371 int val, bit_size, range, code;
372
373 bit_size = s->f_code - 1;
374 range = 1 << bit_size;
375
376 val=mv;
377 if (val < 0)
378 val = -val;
379 val--;
380 code = (val >> bit_size) + 1;
381 if(code<17){
382 len= mbMotionVectorTable[code][1] + 1 + bit_size;
383 }else{
384 len= mbMotionVectorTable[16][1] + 2 + bit_size;
385 }
386 }
387
388 mv_penalty[f_code][mv+MAX_MV]= len;
389 }
390 }
391
392
393 for(f_code=MAX_FCODE; f_code>0; f_code--){
394 for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
395 fcode_tab[mv+MAX_MV]= f_code;
396 }
397 }
398 }
399 s->mv_penalty= mv_penalty;
400 s->fcode_tab= fcode_tab;
401 s->min_qcoeff=-255;
402 s->max_qcoeff= 255;
403 s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
404 s->inter_quant_bias= 0;
405 }
406
407 static inline void encode_dc(MpegEncContext *s, int diff, int component)
408 {
409 if (component == 0) {
410 put_bits(
411 &s->pb,
412 mpeg1_lum_dc_uni[diff+255]&0xFF,
413 mpeg1_lum_dc_uni[diff+255]>>8);
414 } else {
415 put_bits(
416 &s->pb,
417 mpeg1_chr_dc_uni[diff+255]&0xFF,
418 mpeg1_chr_dc_uni[diff+255]>>8);
419 }
420 }
421
422 static void mpeg1_encode_block(MpegEncContext *s,
423 DCTELEM *block,
424 int n)
425 {
426 int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
427 int code, component;
428 // RLTable *rl = &rl_mpeg1;
429
430 last_index = s->block_last_index[n];
431
432 /* DC coef */
433 if (s->mb_intra) {
434 component = (n <= 3 ? 0 : n - 4 + 1);
435 dc = block[0]; /* overflow is impossible */
436 diff = dc - s->last_dc[component];
437 encode_dc(s, diff, component);
438 s->last_dc[component] = dc;
439 i = 1;
440 } else {
441 /* encode the first coefficient : needs to be done here because
442 it is handled slightly differently */
443 level = block[0];
444 if (abs(level) == 1) {
445 code = ((UINT32)level >> 31); /* the sign bit */
446 put_bits(&s->pb, 2, code | 0x02);
447 i = 1;
448 } else {
449 i = 0;
450 last_non_zero = -1;
451 goto next_coef;
452 }
453 }
454
455 /* now quantify & encode AC coefs */
456 last_non_zero = i - 1;
457
458 for(;i<=last_index;i++) {
459 j = zigzag_direct[i];
460 level = block[j];
461 next_coef:
462 #if 0
463 if (level != 0)
464 dprintf("level[%d]=%d\n", i, level);
465 #endif
466 /* encode using VLC */
467 if (level != 0) {
468 run = i - last_non_zero - 1;
469 #ifdef ARCH_X86
470 asm volatile(
471 "movl %2, %1 \n\t"
472 "movl %1, %0 \n\t"
473 "addl %1, %1 \n\t"
474 "sbbl %1, %1 \n\t"
475 "xorl %1, %0 \n\t"
476 "subl %1, %0 \n\t"
477 "andl $1, %1 \n\t"
478 : "=&r" (alevel), "=&r" (sign)
479 : "g" (level)
480 );
481 #else
482 sign = 0;
483 alevel = level;
484 if (alevel < 0) {
485 sign = 1;
486 alevel = -alevel;
487 }
488 #endif
489 // code = get_rl_index(rl, 0, run, alevel);
490 if (alevel > mpeg1_max_level[0][run])
491 code= 111; /*rl->n*/
492 else
493 code= mpeg1_index_run[0][run] + alevel - 1;
494
495 if (code < 111 /* rl->n */) {
496 /* store the vlc & sign at once */
497 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
498 } else {
499 /* escape seems to be pretty rare <5% so i dont optimize it */
500 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
501 /* escape: only clip in this case */
502 put_bits(&s->pb, 6, run);
503 if (alevel < 128) {
504 put_bits(&s->pb, 8, level & 0xff);
505 } else {
506 if (level < 0) {
507 put_bits(&s->pb, 16, 0x8001 + level + 255);
508 } else {
509 put_bits(&s->pb, 16, level & 0xffff);
510 }
511 }
512 }
513 last_non_zero = i;
514 }
515 }
516 /* end of block */
517 put_bits(&s->pb, 2, 0x2);
518 }
519
520 /******************************************/
521 /* decoding */
522
523 static VLC dc_lum_vlc;
524 static VLC dc_chroma_vlc;
525 static VLC mv_vlc;
526 static VLC mbincr_vlc;
527 static VLC mb_ptype_vlc;
528 static VLC mb_btype_vlc;
529 static VLC mb_pat_vlc;
530
531 void mpeg1_init_vlc(MpegEncContext *s)
532 {
533 static int done = 0;
534
535 if (!done) {
536 done = 1;
537
538 init_vlc(&dc_lum_vlc, 9, 12,
539 vlc_dc_lum_bits, 1, 1,
540 vlc_dc_lum_code, 2, 2);
541 init_vlc(&dc_chroma_vlc, 9, 12,
542 vlc_dc_chroma_bits, 1, 1,
543 vlc_dc_chroma_code, 2, 2);
544 init_vlc(&mv_vlc, 9, 17,
545 &mbMotionVectorTable[0][1], 2, 1,
546 &mbMotionVectorTable[0][0], 2, 1);
547 init_vlc(&mbincr_vlc, 9, 35,
548 &mbAddrIncrTable[0][1], 2, 1,
549 &mbAddrIncrTable[0][0], 2, 1);
550 init_vlc(&mb_pat_vlc, 9, 63,
551 &mbPatTable[0][1], 2, 1,
552 &mbPatTable[0][0], 2, 1);
553
554 init_vlc(&mb_ptype_vlc, 6, 32,
555 &table_mb_ptype[0][1], 2, 1,
556 &table_mb_ptype[0][0], 2, 1);
557 init_vlc(&mb_btype_vlc, 6, 32,
558 &table_mb_btype[0][1], 2, 1,
559 &table_mb_btype[0][0], 2, 1);
560 init_rl(&rl_mpeg1);
561 init_rl(&rl_mpeg2);
562 /* cannot use generic init because we must add the EOB code */
563 init_vlc(&rl_mpeg1.vlc, 9, rl_mpeg1.n + 2,
564 &rl_mpeg1.table_vlc[0][1], 4, 2,
565 &rl_mpeg1.table_vlc[0][0], 4, 2);
566 init_vlc(&rl_mpeg2.vlc, 9, rl_mpeg2.n + 2,
567 &rl_mpeg2.table_vlc[0][1], 4, 2,
568 &rl_mpeg2.table_vlc[0][0], 4, 2);
569 }
570 }
571
572 static inline int get_dmv(MpegEncContext *s)
573 {
574 if(get_bits1(&s->gb))
575 return 1 - (get_bits1(&s->gb) << 1);
576 else
577 return 0;
578 }
579
580 static inline int get_qscale(MpegEncContext *s)
581 {
582 int qscale;
583 if (s->mpeg2) {
584 if (s->q_scale_type) {
585 qscale = non_linear_qscale[get_bits(&s->gb, 5)];
586 } else {
587 qscale = get_bits(&s->gb, 5) << 1;
588 }
589 } else {
590 /* for mpeg1, we use the generic unquant code */
591 qscale = get_bits(&s->gb, 5);
592 }
593 return qscale;
594 }
595
596 /* motion type (for mpeg2) */
597 #define MT_FIELD 1
598 #define MT_FRAME 2
599 #define MT_16X8 2
600 #define MT_DMV 3
601
602 static int mpeg_decode_mb(MpegEncContext *s,
603 DCTELEM block[6][64])
604 {
605 int i, j, k, cbp, val, code, mb_type, motion_type;
606
607 /* skip mb handling */
608 if (s->mb_incr == 0) {
609 /* read again increment */
610 s->mb_incr = 1;
611 for(;;) {
612 code = get_vlc(&s->gb, &mbincr_vlc);
613 if (code < 0)
614 return 1; /* error = end of slice */
615 if (code >= 33) {
616 if (code == 33) {
617 s->mb_incr += 33;
618 }
619 /* otherwise, stuffing, nothing to do */
620 } else {
621 s->mb_incr += code;
622 break;
623 }
624 }
625 }
626 if (++s->mb_x >= s->mb_width) {
627 s->mb_x = 0;
628 if (s->mb_y >= (s->mb_height - 1))
629 return -1;
630 s->mb_y++;
631 }
632 dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
633
634 if (--s->mb_incr != 0) {
635 /* skip mb */
636 s->mb_intra = 0;
637 for(i=0;i<6;i++)
638 s->block_last_index[i] = -1;
639 s->mv_type = MV_TYPE_16X16;
640 if (s->pict_type == P_TYPE) {
641 /* if P type, zero motion vector is implied */
642 s->mv_dir = MV_DIR_FORWARD;
643 s->mv[0][0][0] = s->mv[0][0][1] = 0;
644 s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
645 s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
646 } else {
647 /* if B type, reuse previous vectors and directions */
648 s->mv[0][0][0] = s->last_mv[0][0][0];
649 s->mv[0][0][1] = s->last_mv[0][0][1];
650 s->mv[1][0][0] = s->last_mv[1][0][0];
651 s->mv[1][0][1] = s->last_mv[1][0][1];
652 }
653 s->mb_skiped = 1;
654 return 0;
655 }
656
657 switch(s->pict_type) {
658 default:
659 case I_TYPE:
660 if (get_bits1(&s->gb) == 0) {
661 if (get_bits1(&s->gb) == 0)
662 return -1;
663 mb_type = MB_QUANT | MB_INTRA;
664 } else {
665 mb_type = MB_INTRA;
666 }
667 break;
668 case P_TYPE:
669 mb_type = get_vlc(&s->gb, &mb_ptype_vlc);
670 if (mb_type < 0)
671 return -1;
672 break;
673 case B_TYPE:
674 mb_type = get_vlc(&s->gb, &mb_btype_vlc);
675 if (mb_type < 0)
676 return -1;
677 break;
678 }
679 dprintf("mb_type=%x\n", mb_type);
680 motion_type = 0; /* avoid warning */
681 if (mb_type & (MB_FOR|MB_BACK)) {
682 /* get additionnal motion vector type */
683 if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct)
684 motion_type = MT_FRAME;
685 else
686 motion_type = get_bits(&s->gb, 2);
687 }
688 /* compute dct type */
689 if (s->picture_structure == PICT_FRAME &&
690 !s->frame_pred_frame_dct &&
691 (mb_type & (MB_PAT | MB_INTRA))) {
692 s->interlaced_dct = get_bits1(&s->gb);
693 #ifdef DEBUG
694 if (s->interlaced_dct)
695 printf("interlaced_dct\n");
696 #endif
697 } else {
698 s->interlaced_dct = 0; /* frame based */
699 }
700
701 if (mb_type & MB_QUANT) {
702 s->qscale = get_qscale(s);
703 }
704 if (mb_type & MB_INTRA) {
705 if (s->concealment_motion_vectors) {
706 /* just parse them */
707 if (s->picture_structure != PICT_FRAME)
708 skip_bits1(&s->gb); /* field select */
709 mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
710 mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
711 }
712 s->mb_intra = 1;
713 cbp = 0x3f;
714 memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
715 } else {
716 s->mb_intra = 0;
717 cbp = 0;
718 }
719 /* special case of implicit zero motion vector */
720 if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
721 s->mv_dir = MV_DIR_FORWARD;
722 s->mv_type = MV_TYPE_16X16;
723 s->last_mv[0][0][0] = 0;
724 s->last_mv[0][0][1] = 0;
725 s->last_mv[0][1][0] = 0;
726 s->last_mv[0][1][1] = 0;
727 s->mv[0][0][0] = 0;
728 s->mv[0][0][1] = 0;
729 } else if (mb_type & (MB_FOR | MB_BACK)) {
730 /* motion vectors */
731 s->mv_dir = 0;
732 for(i=0;i<2;i++) {
733 if (mb_type & (MB_FOR >> i)) {
734 s->mv_dir |= (MV_DIR_FORWARD >> i);
735 dprintf("motion_type=%d\n", motion_type);
736 switch(motion_type) {
737 case MT_FRAME: /* or MT_16X8 */
738 if (s->picture_structure == PICT_FRAME) {
739 /* MT_FRAME */
740 s->mv_type = MV_TYPE_16X16;
741 for(k=0;k<2;k++) {
742 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
743 s->last_mv[i][0][k]);
744 s->last_mv[i][0][k] = val;
745 s->last_mv[i][1][k] = val;
746 /* full_pel: only for mpeg1 */
747 if (s->full_pel[i])
748 val = val << 1;
749 s->mv[i][0][k] = val;
750 dprintf("mv%d: %d\n", k, val);
751 }
752 } else {
753 /* MT_16X8 */
754 s->mv_type = MV_TYPE_16X8;
755 for(j=0;j<2;j++) {
756 s->field_select[i][j] = get_bits1(&s->gb);
757 for(k=0;k<2;k++) {
758 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
759 s->last_mv[i][j][k]);
760 s->last_mv[i][j][k] = val;
761 s->mv[i][j][k] = val;
762 }
763 }
764 }
765 break;
766 case MT_FIELD:
767 if (s->picture_structure == PICT_FRAME) {
768 s->mv_type = MV_TYPE_FIELD;
769 for(j=0;j<2;j++) {
770 s->field_select[i][j] = get_bits1(&s->gb);
771 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
772 s->last_mv[i][j][0]);
773 s->last_mv[i][j][0] = val;
774 s->mv[i][j][0] = val;
775 dprintf("fmx=%d\n", val);
776 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
777 s->last_mv[i][j][1] >> 1);
778 s->last_mv[i][j][1] = val << 1;
779 s->mv[i][j][1] = val;
780 dprintf("fmy=%d\n", val);
781 }
782 } else {
783 s->mv_type = MV_TYPE_16X16;
784 s->field_select[i][0] = get_bits1(&s->gb);
785 for(k=0;k<2;k++) {
786 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
787 s->last_mv[i][0][k]);
788 s->last_mv[i][0][k] = val;
789 s->last_mv[i][1][k] = val;
790 s->mv[i][0][k] = val;
791 }
792 }
793 break;
794 case MT_DMV:
795 {
796 int dmx, dmy, mx, my, m;
797
798 mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
799 s->last_mv[i][0][0]);
800 s->last_mv[i][0][0] = mx;
801 s->last_mv[i][1][0] = mx;
802 dmx = get_dmv(s);
803 my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
804 s->last_mv[i][0][1] >> 1);
805 dmy = get_dmv(s);
806 s->mv_type = MV_TYPE_DMV;
807 /* XXX: totally broken */
808 if (s->picture_structure == PICT_FRAME) {
809 s->last_mv[i][0][1] = my << 1;
810 s->last_mv[i][1][1] = my << 1;
811
812 m = s->top_field_first ? 1 : 3;
813 /* top -> top pred */
814 s->mv[i][0][0] = mx;
815 s->mv[i][0][1] = my << 1;
816 s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
817 s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
818 m = 4 - m;
819 s->mv[i][2][0] = mx;
820 s->mv[i][2][1] = my << 1;
821 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
822 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
823 } else {
824 s->last_mv[i][0][1] = my;
825 s->last_mv[i][1][1] = my;
826 s->mv[i][0][0] = mx;
827 s->mv[i][0][1] = my;
828 s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
829 s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
830 /* + 2 * cur_field */;
831 }
832 }
833 break;
834 }
835 }
836 }
837 }
838
839 if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
840 skip_bits1(&s->gb); /* marker */
841 }
842
843 if (mb_type & MB_PAT) {
844 cbp = get_vlc(&s->gb, &mb_pat_vlc);
845 if (cbp < 0)
846 return -1;
847 cbp++;
848 }
849 dprintf("cbp=%x\n", cbp);
850
851 if (s->mpeg2) {
852 if (s->mb_intra) {
853 for(i=0;i<6;i++) {
854 if (cbp & (1 << (5 - i))) {
855 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
856 return -1;
857 } else {
858 s->block_last_index[i] = -1;
859 }
860 }
861 } else {
862 for(i=0;i<6;i++) {
863 if (cbp & (1 << (5 - i))) {
864 if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
865 return -1;
866 } else {
867 s->block_last_index[i] = -1;
868 }
869 }
870 }
871 } else {
872 for(i=0;i<6;i++) {
873 if (cbp & (1 << (5 - i))) {
874 if (mpeg1_decode_block(s, block[i], i) < 0)
875 return -1;
876 } else {
877 s->block_last_index[i] = -1;
878 }
879 }
880 }
881 return 0;
882 }
883
884 /* as h263, but only 17 codes */
885 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
886 {
887 int code, sign, val, m, l, shift;
888
889 code = get_vlc(&s->gb, &mv_vlc);
890 if (code < 0) {
891 return 0xffff;
892 }
893 if (code == 0) {
894 return pred;
895 }
896 sign = get_bits1(&s->gb);
897 shift = fcode - 1;
898 val = (code - 1) << shift;
899 if (shift > 0)
900 val |= get_bits(&s->gb, shift);
901 val++;
902 if (sign)
903 val = -val;
904 val += pred;
905
906 /* modulo decoding */
907 l = (1 << shift) * 16;
908 m = 2 * l;
909 if (val < -l) {
910 val += m;
911 } else if (val >= l) {
912 val -= m;
913 }
914 return val;
915 }
916
917 static inline int decode_dc(MpegEncContext *s, int component)
918 {
919 int code, diff;
920
921 if (component == 0) {
922 code = get_vlc(&s->gb, &dc_lum_vlc);
923 } else {
924 code = get_vlc(&s->gb, &dc_chroma_vlc);
925 }
926 if (code < 0)
927 return 0xffff;
928 if (code == 0) {
929 diff = 0;
930 } else {
931 diff = get_bits(&s->gb, code);
932 if ((diff & (1 << (code - 1))) == 0)
933 diff = (-1 << code) | (diff + 1);
934 }
935 return diff;
936 }
937
938 static int mpeg1_decode_block(MpegEncContext *s,
939 DCTELEM *block,
940 int n)
941 {
942 int level, dc, diff, i, j, run;
943 int code, component;
944 RLTable *rl = &rl_mpeg1;
945
946 if (s->mb_intra) {
947 /* DC coef */
948 component = (n <= 3 ? 0 : n - 4 + 1);
949 diff = decode_dc(s, component);
950 if (diff >= 0xffff)
951 return -1;
952 dc = s->last_dc[component];
953 dc += diff;
954 s->last_dc[component] = dc;
955 block[0] = dc;
956 dprintf("dc=%d diff=%d\n", dc, diff);
957 i = 1;
958 } else {
959 int bit_cnt, v;
960 UINT32 bit_buf;
961 UINT8 *buf_ptr;
962 i = 0;
963 /* special case for the first coef. no need to add a second vlc table */
964 SAVE_BITS(&s->gb);
965 SHOW_BITS(&s->gb, v, 2);
966 if (v & 2) {
967 run = 0;
968 level = 1 - ((v & 1) << 1);
969 FLUSH_BITS(2);
970 RESTORE_BITS(&s->gb);
971 goto add_coef;
972 }
973 RESTORE_BITS(&s->gb);
974 }
975
976 /* now quantify & encode AC coefs */
977 for(;;) {
978 code = get_vlc(&s->gb, &rl->vlc);
979 if (code < 0) {
980 return -1;
981 }
982 if (code == 112) {
983 break;
984 } else if (code == 111) {
985 /* escape */
986 run = get_bits(&s->gb, 6);
987 level = get_bits(&s->gb, 8);
988 level = (level << 24) >> 24;
989 if (level == -128) {
990 level = get_bits(&s->gb, 8) - 256;
991 } else if (level == 0) {
992 level = get_bits(&s->gb, 8);
993 }
994 } else {
995 run = rl->table_run[code];
996 level = rl->table_level[code];
997 if (get_bits1(&s->gb))
998 level = -level;
999 }
1000 i += run;
1001 if (i >= 64)
1002 return -1;
1003 add_coef:
1004 dprintf("%d: run=%d level=%d\n", n, run, level);
1005 j = zigzag_direct[i];
1006 block[j] = level;
1007 i++;
1008 }
1009 s->block_last_index[n] = i-1;
1010 return 0;
1011 }
1012
1013 /* Also does unquantization here, since I will never support mpeg2
1014 encoding */
1015 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
1016 DCTELEM *block,
1017 int n)
1018 {
1019 int level, i, j, run;
1020 int code;
1021 RLTable *rl = &rl_mpeg1;
1022 const UINT8 *scan_table;
1023 const UINT16 *matrix;
1024 int mismatch;
1025
1026 if (s->alternate_scan)
1027 scan_table = ff_alternate_vertical_scan;
1028 else
1029 scan_table = zigzag_direct;
1030 mismatch = 1;
1031
1032 {
1033 int bit_cnt, v;
1034 UINT32 bit_buf;
1035 UINT8 *buf_ptr;
1036 i = 0;
1037 if (n < 4)
1038 matrix = s->inter_matrix;
1039 else
1040 matrix = s->chroma_inter_matrix;
1041
1042 /* special case for the first coef. no need to add a second vlc table */
1043 SAVE_BITS(&s->gb);
1044 SHOW_BITS(&s->gb, v, 2);
1045 if (v & 2) {
1046 run = 0;
1047 level = 1 - ((v & 1) << 1);
1048 FLUSH_BITS(2);
1049 RESTORE_BITS(&s->gb);
1050 goto add_coef;
1051 }
1052 RESTORE_BITS(&s->gb);
1053 }
1054
1055 /* now quantify & encode AC coefs */
1056 for(;;) {
1057 code = get_vlc(&s->gb, &rl->vlc);
1058 if (code < 0)
1059 return -1;
1060 if (code == 112) {
1061 break;
1062 } else if (code == 111) {
1063 /* escape */
1064 run = get_bits(&s->gb, 6);
1065 level = get_bits(&s->gb, 12);
1066 level = (level << 20) >> 20;
1067 } else {
1068 run = rl->table_run[code];
1069 level = rl->table_level[code];
1070 if (get_bits1(&s->gb))
1071 level = -level;
1072 }
1073 i += run;
1074 if (i >= 64)
1075 return -1;
1076 add_coef:
1077 j = scan_table[i];
1078 dprintf("%d: run=%d level=%d\n", n, run, level);
1079 /* XXX: optimize */
1080 if (level > 0) {
1081 level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1082 } else {
1083 level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1084 level = -level;
1085 }
1086 /* XXX: is it really necessary to saturate since the encoder
1087 knows whats going on ? */
1088 mismatch ^= level;
1089 block[j] = level;
1090 i++;
1091 }
1092 block[63] ^= (mismatch & 1);
1093 s->block_last_index[n] = i;
1094 return 0;
1095 }
1096
1097 static int mpeg2_decode_block_intra(MpegEncContext *s,
1098 DCTELEM *block,
1099 int n)
1100 {
1101 int level, dc, diff, i, j, run;
1102 int code, component;
1103 RLTable *rl;
1104 const UINT8 *scan_table;
1105 const UINT16 *matrix;
1106 int mismatch;
1107
1108 if (s->alternate_scan)
1109 scan_table = ff_alternate_vertical_scan;
1110 else
1111 scan_table = zigzag_direct;
1112
1113 /* DC coef */
1114 component = (n <= 3 ? 0 : n - 4 + 1);
1115 diff = decode_dc(s, component);
1116 if (diff >= 0xffff)
1117 return -1;
1118 dc = s->last_dc[component];
1119 dc += diff;
1120 s->last_dc[component] = dc;
1121 block[0] = dc << (3 - s->intra_dc_precision);
1122 dprintf("dc=%d\n", block[0]);
1123 mismatch = block[0] ^ 1;
1124 i = 1;
1125 if (s->intra_vlc_format)
1126 rl = &rl_mpeg2;
1127 else
1128 rl = &rl_mpeg1;
1129 if (n < 4)
1130 matrix = s->intra_matrix;
1131 else
1132 matrix = s->chroma_intra_matrix;
1133
1134 /* now quantify & encode AC coefs */
1135 for(;;) {
1136 code = get_vlc(&s->gb, &rl->vlc);
1137 if (code < 0)
1138 return -1;
1139 if (code == 112) {
1140 break;
1141 } else if (code == 111) {
1142 /* escape */
1143 run = get_bits(&s->gb, 6);
1144 level = get_bits(&s->gb, 12);
1145 level = (level << 20) >> 20;
1146 } else {
1147 run = rl->table_run[code];
1148 level = rl->table_level[code];
1149 if (get_bits1(&s->gb))
1150 level = -level;
1151 }
1152 i += run;
1153 if (i >= 64)
1154 return -1;
1155 j = scan_table[i];
1156 dprintf("%d: run=%d level=%d\n", n, run, level);
1157 level = (level * s->qscale * matrix[j]) / 16;
1158 /* XXX: is it really necessary to saturate since the encoder
1159 knows whats going on ? */
1160 mismatch ^= level;
1161 block[j] = level;
1162 i++;
1163 }
1164 block[63] ^= (mismatch & 1);
1165 s->block_last_index[n] = i;
1166 return 0;
1167 }
1168
1169 /* compressed picture size */
1170 #define PICTURE_BUFFER_SIZE 100000
1171
1172 typedef struct Mpeg1Context {
1173 MpegEncContext mpeg_enc_ctx;
1174 UINT32 header_state;
1175 int start_code; /* current start code */
1176 UINT8 buffer[PICTURE_BUFFER_SIZE];
1177 UINT8 *buf_ptr;
1178 int buffer_size;
1179 int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1180 int repeat_field; /* true if we must repeat the field */
1181 } Mpeg1Context;
1182
1183 static int mpeg_decode_init(AVCodecContext *avctx)
1184 {
1185 Mpeg1Context *s = avctx->priv_data;
1186
1187 s->header_state = 0xff;
1188 s->mpeg_enc_ctx_allocated = 0;
1189 s->buffer_size = PICTURE_BUFFER_SIZE;
1190 s->start_code = -1;
1191 s->buf_ptr = s->buffer;
1192 s->mpeg_enc_ctx.picture_number = 0;
1193 s->repeat_field = 0;
1194 s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1195 avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1196 s->mpeg_enc_ctx.flags= avctx->flags;
1197 return 0;
1198 }
1199
1200 /* return the 8 bit start code value and update the search
1201 state. Return -1 if no start code found */
1202 static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end,
1203 UINT32 *header_state)
1204 {
1205 UINT8 *buf_ptr;
1206 unsigned int state, v;
1207 int val;
1208
1209 state = *header_state;
1210 buf_ptr = *pbuf_ptr;
1211 while (buf_ptr < buf_end) {
1212 v = *buf_ptr++;
1213 if (state == 0x000001) {
1214 state = ((state << 8) | v) & 0xffffff;
1215 val = state;
1216 goto found;
1217 }
1218 state = ((state << 8) | v) & 0xffffff;
1219 }
1220 val = -1;
1221 found:
1222 *pbuf_ptr = buf_ptr;
1223 *header_state = state;
1224 return val;
1225 }
1226
1227 static int mpeg1_decode_picture(AVCodecContext *avctx,
1228 UINT8 *buf, int buf_size)
1229 {
1230 Mpeg1Context *s1 = avctx->priv_data;
1231 MpegEncContext *s = &s1->mpeg_enc_ctx;
1232 int ref, f_code;
1233
1234 init_get_bits(&s->gb, buf, buf_size);
1235
1236 ref = get_bits(&s->gb, 10); /* temporal ref */
1237 s->pict_type = get_bits(&s->gb, 3);
1238 dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1239 skip_bits(&s->gb, 16);
1240 if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1241 s->full_pel[0] = get_bits1(&s->gb);
1242 f_code = get_bits(&s->gb, 3);
1243 if (f_code == 0)
1244 return -1;
1245 s->mpeg_f_code[0][0] = f_code;
1246 s->mpeg_f_code[0][1] = f_code;
1247 }
1248 if (s->pict_type == B_TYPE) {
1249 s->full_pel[1] = get_bits1(&s->gb);
1250 f_code = get_bits(&s->gb, 3);
1251 if (f_code == 0)
1252 return -1;
1253 s->mpeg_f_code[1][0] = f_code;
1254 s->mpeg_f_code[1][1] = f_code;
1255 }
1256 s->y_dc_scale = 8;
1257 s->c_dc_scale = 8;
1258 s->first_slice = 1;
1259 return 0;
1260 }
1261
1262 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1263 {
1264 int horiz_size_ext, vert_size_ext;
1265 int bit_rate_ext, vbv_buf_ext, low_delay;
1266 int frame_rate_ext_n, frame_rate_ext_d;
1267
1268 skip_bits(&s->gb, 8); /* profil and level */
1269 s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1270 skip_bits(&s->gb, 2); /* chroma_format */
1271 horiz_size_ext = get_bits(&s->gb, 2);
1272 vert_size_ext = get_bits(&s->gb, 2);
1273 s->width |= (horiz_size_ext << 12);
1274 s->height |= (vert_size_ext << 12);
1275 bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */
1276 s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1277 skip_bits1(&s->gb); /* marker */
1278 vbv_buf_ext = get_bits(&s->gb, 8);
1279 low_delay = get_bits1(&s->gb);
1280 frame_rate_ext_n = get_bits(&s->gb, 2);
1281 frame_rate_ext_d = get_bits(&s->gb, 5);
1282 if (frame_rate_ext_d >= 1)
1283 s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1284 dprintf("sequence extension\n");
1285 s->mpeg2 = 1;
1286 s->avctx->sub_id = 2; /* indicates mpeg2 found */
1287 }
1288
1289 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1290 {
1291 int i, v, j;
1292
1293 dprintf("matrix extension\n");
1294
1295 if (get_bits1(&s->gb)) {
1296 for(i=0;i<64;i++) {
1297 v = get_bits(&s->gb, 8);
1298 j = zigzag_direct[i];
1299 s->intra_matrix[j] = v;
1300 s->chroma_intra_matrix[j] = v;
1301 }
1302 }
1303 if (get_bits1(&s->gb)) {
1304 for(i=0;i<64;i++) {
1305 v = get_bits(&s->gb, 8);
1306 j = zigzag_direct[i];
1307 s->inter_matrix[j] = v;
1308 s->chroma_inter_matrix[j] = v;
1309 }
1310 }
1311 if (get_bits1(&s->gb)) {
1312 for(i=0;i<64;i++) {
1313 v = get_bits(&s->gb, 8);
1314 j = zigzag_direct[i];
1315 s->chroma_intra_matrix[j] = v;
1316 }
1317 }
1318 if (get_bits1(&s->gb)) {
1319 for(i=0;i<64;i++) {
1320 v = get_bits(&s->gb, 8);
1321 j = zigzag_direct[i];
1322 s->chroma_inter_matrix[j] = v;
1323 }
1324 }
1325 }
1326
1327 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1328 {
1329 s->full_pel[0] = s->full_pel[1] = 0;
1330 s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1331 s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1332 s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1333 s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1334 s->intra_dc_precision = get_bits(&s->gb, 2);
1335 s->picture_structure = get_bits(&s->gb, 2);
1336 s->top_field_first = get_bits1(&s->gb);
1337 s->frame_pred_frame_dct = get_bits1(&s->gb);
1338 s->concealment_motion_vectors = get_bits1(&s->gb);
1339 s->q_scale_type = get_bits1(&s->gb);
1340 s->intra_vlc_format = get_bits1(&s->gb);
1341 s->alternate_scan = get_bits1(&s->gb);
1342 s->repeat_first_field = get_bits1(&s->gb);
1343 s->chroma_420_type = get_bits1(&s->gb);
1344 s->progressive_frame = get_bits1(&s->gb);
1345 /* composite display not parsed */
1346 dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1347 dprintf("picture_structure=%d\n", s->picture_structure);
1348 dprintf("top field first=%d\n", s->top_field_first);
1349 dprintf("repeat first field=%d\n", s->repeat_first_field);
1350 dprintf("conceal=%d\n", s->concealment_motion_vectors);
1351 dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1352 dprintf("alternate_scan=%d\n", s->alternate_scan);
1353 dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1354 dprintf("progressive_frame=%d\n", s->progressive_frame);
1355 }
1356
1357 static void mpeg_decode_extension(AVCodecContext *avctx,
1358 UINT8 *buf, int buf_size)
1359 {
1360 Mpeg1Context *s1 = avctx->priv_data;
1361 MpegEncContext *s = &s1->mpeg_enc_ctx;
1362 int ext_type;
1363
1364 init_get_bits(&s->gb, buf, buf_size);
1365
1366 ext_type = get_bits(&s->gb, 4);
1367 switch(ext_type) {
1368 case 0x1:
1369 /* sequence ext */
1370 mpeg_decode_sequence_extension(s);
1371 break;
1372 case 0x3:
1373 /* quant matrix extension */
1374 mpeg_decode_quant_matrix_extension(s);
1375 break;
1376 case 0x8:
1377 /* picture extension */
1378 mpeg_decode_picture_coding_extension(s);
1379 break;
1380 }
1381 }
1382
1383 /* return 1 if end of frame */
1384 static int mpeg_decode_slice(AVCodecContext *avctx,
1385 AVPicture *pict,
1386 int start_code,
1387 UINT8 *buf, int buf_size)
1388 {
1389 Mpeg1Context *s1 = avctx->priv_data;
1390 MpegEncContext *s = &s1->mpeg_enc_ctx;
1391 int ret;
1392
1393 start_code = (start_code - 1) & 0xff;
1394 if (start_code >= s->mb_height)
1395 return -1;
1396 s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1397 s->last_dc[1] = s->last_dc[0];
1398 s->last_dc[2] = s->last_dc[0];
1399 memset(s->last_mv, 0, sizeof(s->last_mv));
1400 s->mb_x = -1;
1401 s->mb_y = start_code;
1402 s->mb_incr = 0;
1403 /* start frame decoding */
1404 if (s->first_slice) {
1405 s->first_slice = 0;
1406 MPV_frame_start(s);
1407 }
1408
1409 init_get_bits(&s->gb, buf, buf_size);
1410
1411 s->qscale = get_qscale(s);
1412 /* extra slice info */
1413 while (get_bits1(&s->gb) != 0) {
1414 skip_bits(&s->gb, 8);
1415 }
1416
1417 for(;;) {
1418 clear_blocks(s->block[0]);
1419 emms_c();
1420 ret = mpeg_decode_mb(s, s->block);
1421 dprintf("ret=%d\n", ret);
1422 if (ret < 0)
1423 return -1;
1424 if (ret == 1)
1425 break;
1426 MPV_decode_mb(s, s->block);
1427 }
1428 emms_c();
1429
1430 /* end of slice reached */
1431 if (s->mb_x == (s->mb_width - 1) &&
1432 s->mb_y == (s->mb_height - 1)) {
1433 /* end of image */
1434 UINT8 **picture;
1435
1436 MPV_frame_end(s);
1437
1438 /* XXX: incorrect reported qscale for mpeg2 */
1439 if (s->pict_type == B_TYPE) {
1440 picture = s->current_picture;
1441 avctx->quality = s->qscale;
1442 } else {
1443 /* latency of 1 frame for I and P frames */
1444 /* XXX: use another variable than picture_number */
1445 if (s->picture_number == 0) {
1446 picture = NULL;
1447 } else {
1448 picture = s->last_picture;
1449 avctx->quality = s->last_qscale;
1450 }
1451 s->last_qscale = s->qscale;
1452 s->picture_number++;
1453 }
1454 if (picture) {
1455 pict->data[0] = picture[0];
1456 pict->data[1] = picture[1];
1457 pict->data[2] = picture[2];
1458 pict->linesize[0] = s->linesize;
1459 pict->linesize[1] = s->linesize / 2;
1460 pict->linesize[2] = s->linesize / 2;
1461 return 1;
1462 } else {
1463 return 0;
1464 }
1465 } else {
1466 return 0;
1467 }
1468 }
1469
1470 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1471 UINT8 *buf, int buf_size)
1472 {
1473 Mpeg1Context *s1 = avctx->priv_data;
1474 MpegEncContext *s = &s1->mpeg_enc_ctx;
1475 int width, height, i, v, j;
1476
1477 init_get_bits(&s->gb, buf, buf_size);
1478
1479 width = get_bits(&s->gb, 12);
1480 height = get_bits(&s->gb, 12);
1481 skip_bits(&s->gb, 4);
1482 s->frame_rate_index = get_bits(&s->gb, 4);
1483 if (s->frame_rate_index == 0)
1484 return -1;
1485 s->bit_rate = get_bits(&s->gb, 18) * 400;
1486 if (get_bits1(&s->gb) == 0) /* marker */
1487 return -1;
1488 if (width <= 0 || height <= 0 ||
1489 (width % 2) != 0 || (height % 2) != 0)
1490 return -1;
1491 if (width != s->width ||
1492 height != s->height) {
1493 /* start new mpeg1 context decoding */
1494 s->out_format = FMT_MPEG1;
1495 if (s1->mpeg_enc_ctx_allocated) {
1496 MPV_common_end(s);
1497 }
1498 s->width = width;
1499 s->height = height;
1500 s->has_b_frames = 1;
1501 s->avctx = avctx;
1502 avctx->width = width;
1503 avctx->height = height;
1504 if (s->frame_rate_index >= 9) {
1505 /* at least give a valid frame rate (some old mpeg1 have this) */
1506 avctx->frame_rate = 25 * FRAME_RATE_BASE;
1507 } else {
1508 avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1509 }
1510 s->frame_rate = avctx->frame_rate;
1511 avctx->bit_rate = s->bit_rate;
1512
1513 if (MPV_common_init(s) < 0)
1514 return -1;
1515 mpeg1_init_vlc(s);
1516 s1->mpeg_enc_ctx_allocated = 1;
1517 }
1518
1519 skip_bits(&s->gb, 10); /* vbv_buffer_size */
1520 skip_bits(&s->gb, 1);
1521
1522 /* get matrix */
1523 if (get_bits1(&s->gb)) {
1524 for(i=0;i<64;i++) {
1525 v = get_bits(&s->gb, 8);
1526 j = zigzag_direct[i];
1527 s->intra_matrix[j] = v;
1528 s->chroma_intra_matrix[j] = v;
1529 }
1530 #ifdef DEBUG
1531 dprintf("intra matrix present\n");
1532 for(i=0;i<64;i++)
1533 dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1534 printf("\n");
1535 #endif
1536 } else {
1537 for(i=0;i<64;i++) {
1538 v = default_intra_matrix[i];
1539 s->intra_matrix[i] = v;
1540 s->chroma_intra_matrix[i] = v;
1541 }
1542 }
1543 if (get_bits1(&s->gb)) {
1544 for(i=0;i<64;i++) {
1545 v = get_bits(&s->gb, 8);
1546 j = zigzag_direct[i];
1547 s->inter_matrix[j] = v;
1548 s->chroma_inter_matrix[j] = v;
1549 }
1550 #ifdef DEBUG
1551 dprintf("non intra matrix present\n");
1552 for(i=0;i<64;i++)
1553 dprintf(" %d", s->inter_matrix[zigzag_direct[i]]);
1554 printf("\n");
1555 #endif
1556 } else {
1557 for(i=0;i<64;i++) {
1558 v = default_non_intra_matrix[i];
1559 s->inter_matrix[i] = v;
1560 s->chroma_inter_matrix[i] = v;
1561 }
1562 }
1563
1564 /* we set mpeg2 parameters so that it emulates mpeg1 */
1565 s->progressive_sequence = 1;
1566 s->progressive_frame = 1;
1567 s->picture_structure = PICT_FRAME;
1568 s->frame_pred_frame_dct = 1;
1569 s->mpeg2 = 0;
1570 avctx->sub_id = 1; /* indicates mpeg1 */
1571 return 0;
1572 }
1573
1574 /* handle buffering and image synchronisation */
1575 static int mpeg_decode_frame(AVCodecContext *avctx,
1576 void *data, int *data_size,
1577 UINT8 *buf, int buf_size)
1578 {
1579 Mpeg1Context *s = avctx->priv_data;
1580 UINT8 *buf_end, *buf_ptr, *buf_start;
1581 int len, start_code_found, ret, code, start_code, input_size;
1582 AVPicture *picture = data;
1583 MpegEncContext *s2 = &s->mpeg_enc_ctx;
1584
1585 dprintf("fill_buffer\n");
1586
1587 *data_size = 0;
1588
1589 /* special case for last picture */
1590 if (buf_size == 0) {
1591 if (s2->picture_number > 0) {
1592 picture->data[0] = s2->next_picture[0];
1593 picture->data[1] = s2->next_picture[1];
1594 picture->data[2] = s2->next_picture[2];
1595 picture->linesize[0] = s2->linesize;
1596 picture->linesize[1] = s2->linesize / 2;
1597 picture->linesize[2] = s2->linesize / 2;
1598 *data_size = sizeof(AVPicture);
1599 }
1600 return 0;
1601 }
1602
1603 buf_ptr = buf;
1604 buf_end = buf + buf_size;
1605
1606 #if 0
1607 if (s->repeat_field % 2 == 1) {
1608 s->repeat_field++;
1609 //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1610 // s2->picture_number, s->repeat_field);
1611 if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
1612 *data_size = sizeof(AVPicture);
1613 goto the_end;
1614 }
1615 }
1616 #endif
1617 while (buf_ptr < buf_end) {
1618 buf_start = buf_ptr;
1619 /* find start next code */
1620 code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1621 if (code >= 0) {
1622 start_code_found = 1;
1623 } else {
1624 start_code_found = 0;
1625 }
1626 /* copy to buffer */
1627 len = buf_ptr - buf_start;
1628 if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1629 /* data too big : flush */
1630 s->buf_ptr = s->buffer;
1631 if (start_code_found)
1632 s->start_code = code;
1633 } else {
1634 memcpy(s->buf_ptr, buf_start, len);
1635 s->buf_ptr += len;
1636
1637 if (start_code_found) {
1638 /* prepare data for next start code */
1639 input_size = s->buf_ptr - s->buffer;
1640 start_code = s->start_code;
1641 s->buf_ptr = s->buffer;
1642 s->start_code = code;
1643 switch(start_code) {
1644 case SEQ_START_CODE:
1645 mpeg1_decode_sequence(avctx, s->buffer,
1646 input_size);
1647 break;
1648
1649 case PICTURE_START_CODE:
1650 /* we have a complete image : we try to decompress it */
1651 mpeg1_decode_picture(avctx,
1652 s->buffer, input_size);
1653 break;
1654 case EXT_START_CODE:
1655 mpeg_decode_extension(avctx,
1656 s->buffer, input_size);
1657 break;
1658 default:
1659 if (start_code >= SLICE_MIN_START_CODE &&
1660 start_code <= SLICE_MAX_START_CODE) {
1661 ret = mpeg_decode_slice(avctx, picture,
1662 start_code, s->buffer, input_size);
1663 if (ret == 1) {
1664 /* got a picture: exit */
1665 /* first check if we must repeat the frame */
1666 avctx->repeat_pict = 0;
1667 #if 0
1668 if (s2->progressive_frame && s2->repeat_first_field) {
1669 //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1670 //s2->repeat_first_field = 0;
1671 //s2->progressive_frame = 0;
1672 if (++s->repeat_field > 2)
1673 s->repeat_field = 0;
1674 avctx->repeat_pict = 1;
1675 }
1676 #endif
1677 if (s2->repeat_first_field) {
1678 if (s2->progressive_sequence) {
1679 if (s2->top_field_first)
1680 avctx->repeat_pict = 4;
1681 else
1682 avctx->repeat_pict = 2;
1683 } else if (s2->progressive_frame) {
1684 avctx->repeat_pict = 1;
1685 }
1686 }
1687 *data_size = sizeof(AVPicture);
1688 goto the_end;
1689 }
1690 }
1691 break;
1692 }
1693 }
1694 }
1695 }
1696 the_end:
1697 return buf_ptr - buf;
1698 }
1699
1700 static int mpeg_decode_end(AVCodecContext *avctx)
1701 {
1702 Mpeg1Context *s = avctx->priv_data;
1703
1704 if (s->mpeg_enc_ctx_allocated)
1705 MPV_common_end(&s->mpeg_enc_ctx);
1706 return 0;
1707 }
1708
1709 AVCodec mpeg_decoder = {
1710 "mpegvideo",
1711 CODEC_TYPE_VIDEO,
1712 CODEC_ID_MPEG1VIDEO,
1713 sizeof(Mpeg1Context),
1714 mpeg_decode_init,
1715 NULL,
1716 mpeg_decode_end,
1717 mpeg_decode_frame,
1718 };
Libav master