2 * MPEG1 encoder / MPEG2 decoder
3 * Copyright (c) 2000,2001 Fabrice Bellard.
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.
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.
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
22 #include "mpegvideo.h"
24 #include "mpeg12data.h"
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
38 #define MBINCR_VLC_BITS 9
39 #define MB_PAT_VLC_BITS 9
40 #define MB_PTYPE_VLC_BITS 6
41 #define MB_BTYPE_VLC_BITS 6
42 #define TEX_VLC_BITS 9
44 static void mpeg1_encode_block(MpegEncContext *s,
47 static void mpeg1_encode_motion(MpegEncContext *s, int val);
48 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
49 static int mpeg1_decode_block(MpegEncContext *s,
52 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
55 static int mpeg2_decode_block_intra(MpegEncContext *s,
58 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
60 static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
61 static UINT8 fcode_tab[MAX_MV*2+1];
63 static void init_2d_vlc_rl(RLTable *rl)
67 init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2,
68 &rl->table_vlc[0][1], 4, 2,
69 &rl->table_vlc[0][0], 4, 2);
72 rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
73 for(i=0; i<rl->vlc.table_size; i++){
74 int code= rl->vlc.table[i][0];
75 int len = rl->vlc.table[i][1];
78 if(len==0){ // illegal code
81 }else if(len<0){ //more bits needed
85 if(code==rl->n){ //esc
88 }else if(code==rl->n+1){ //eob
92 run= rl->table_run [code] + 1;
93 level= rl->table_level[code];
96 rl->rl_vlc[0][i].len= len;
97 rl->rl_vlc[0][i].level= level;
98 rl->rl_vlc[0][i].run= run;
103 static void put_header(MpegEncContext *s, int header)
105 align_put_bits(&s->pb);
106 put_bits(&s->pb, 16, header>>16);
107 put_bits(&s->pb, 16, header&0xFFFF);
110 /* put sequence header if needed */
111 static void mpeg1_encode_sequence_header(MpegEncContext *s)
113 unsigned int vbv_buffer_size;
118 if (s->picture_in_gop_number == 0) {
119 /* mpeg1 header repeated every gop */
120 put_header(s, SEQ_START_CODE);
122 /* search closest frame rate */
125 s->frame_rate_index = 0;
128 d = abs(s->frame_rate - frame_rate_tab[i]);
131 s->frame_rate_index = i;
136 put_bits(&s->pb, 12, s->width);
137 put_bits(&s->pb, 12, s->height);
138 put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
139 put_bits(&s->pb, 4, s->frame_rate_index);
140 v = s->bit_rate / 400;
143 put_bits(&s->pb, 18, v);
144 put_bits(&s->pb, 1, 1); /* marker */
145 /* vbv buffer size: slightly greater than an I frame. We add
146 some margin just in case */
147 vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
148 put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
149 put_bits(&s->pb, 1, 1); /* constrained parameter flag */
150 put_bits(&s->pb, 1, 0); /* no custom intra matrix */
151 put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
153 put_header(s, GOP_START_CODE);
154 put_bits(&s->pb, 1, 0); /* do drop frame */
155 /* time code : we must convert from the real frame rate to a
156 fake mpeg frame rate in case of low frame rate */
157 fps = frame_rate_tab[s->frame_rate_index];
158 time_code = (INT64)s->fake_picture_number * FRAME_RATE_BASE;
159 s->gop_picture_number = s->fake_picture_number;
160 put_bits(&s->pb, 5, (UINT32)((time_code / (fps * 3600)) % 24));
161 put_bits(&s->pb, 6, (UINT32)((time_code / (fps * 60)) % 60));
162 put_bits(&s->pb, 1, 1);
163 put_bits(&s->pb, 6, (UINT32)((time_code / fps) % 60));
164 put_bits(&s->pb, 6, (UINT32)((time_code % fps) / FRAME_RATE_BASE));
165 put_bits(&s->pb, 1, 1); /* closed gop */
166 put_bits(&s->pb, 1, 0); /* broken link */
169 if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
170 /* insert empty P pictures to slow down to the desired
171 frame rate. Each fake pictures takes about 20 bytes */
172 fps = frame_rate_tab[s->frame_rate_index];
173 n = (((INT64)s->picture_number * fps) / s->frame_rate) - 1;
174 while (s->fake_picture_number < n) {
175 mpeg1_skip_picture(s, s->fake_picture_number -
176 s->gop_picture_number);
177 s->fake_picture_number++;
184 /* insert a fake P picture */
185 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
187 unsigned int mb_incr;
189 /* mpeg1 picture header */
190 put_header(s, PICTURE_START_CODE);
191 /* temporal reference */
192 put_bits(&s->pb, 10, pict_num & 0x3ff);
194 put_bits(&s->pb, 3, P_TYPE);
195 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
197 put_bits(&s->pb, 1, 1); /* integer coordinates */
198 put_bits(&s->pb, 3, 1); /* forward_f_code */
200 put_bits(&s->pb, 1, 0); /* extra bit picture */
203 put_header(s, SLICE_MIN_START_CODE);
204 put_bits(&s->pb, 5, 1); /* quantizer scale */
205 put_bits(&s->pb, 1, 0); /* slice extra information */
208 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
209 mbAddrIncrTable[mb_incr - 1][0]);
211 /* empty macroblock */
212 put_bits(&s->pb, 3, 1); /* motion only */
214 /* zero motion x & y */
215 put_bits(&s->pb, 1, 1);
216 put_bits(&s->pb, 1, 1);
218 /* output a number of empty slice */
219 mb_incr = s->mb_width * s->mb_height - 1;
220 while (mb_incr > 33) {
221 put_bits(&s->pb, 11, 0x008);
224 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
225 mbAddrIncrTable[mb_incr - 1][0]);
227 /* empty macroblock */
228 put_bits(&s->pb, 3, 1); /* motion only */
230 /* zero motion x & y */
231 put_bits(&s->pb, 1, 1);
232 put_bits(&s->pb, 1, 1);
235 static void common_init(MpegEncContext *s)
238 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
241 void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
243 mpeg1_encode_sequence_header(s);
245 /* mpeg1 picture header */
246 put_header(s, PICTURE_START_CODE);
247 /* temporal reference */
248 put_bits(&s->pb, 10, (s->fake_picture_number -
249 s->gop_picture_number) & 0x3ff);
250 s->fake_picture_number++;
252 put_bits(&s->pb, 3, s->pict_type);
253 put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
255 if (s->pict_type == P_TYPE) {
256 put_bits(&s->pb, 1, 0); /* half pel coordinates */
257 put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
260 put_bits(&s->pb, 1, 0); /* extra bit picture */
263 put_header(s, SLICE_MIN_START_CODE);
264 put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
265 put_bits(&s->pb, 1, 0); /* slice extra information */
268 void mpeg1_encode_mb(MpegEncContext *s,
269 DCTELEM block[6][64],
270 int motion_x, int motion_y)
272 int mb_incr, i, cbp, mb_x, mb_y;
280 if (s->block_last_index[i] >= 0)
284 /* skip macroblock, except if first or last macroblock of a slice */
285 if ((cbp | motion_x | motion_y) == 0 &&
286 (!((mb_x | mb_y) == 0 ||
287 (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
291 mb_incr = s->mb_incr;
293 while (mb_incr > 33) {
294 put_bits(&s->pb, 11, 0x008);
297 put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
298 mbAddrIncrTable[mb_incr - 1][0]);
300 if (s->pict_type == I_TYPE) {
301 put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
304 put_bits(&s->pb, 5, 0x03);
307 if (motion_x == 0 && motion_y == 0) {
308 put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
309 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
311 put_bits(&s->pb, 1, 1); /* motion + cbp */
312 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
313 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
314 put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
317 put_bits(&s->pb, 3, 1); /* motion only */
318 mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
319 mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
324 if (cbp & (1 << (5 - i))) {
325 mpeg1_encode_block(s, block[i], i);
330 s->last_mv[0][0][0] = motion_x;
331 s->last_mv[0][0][1] = motion_y;
334 static void mpeg1_encode_motion(MpegEncContext *s, int val)
336 int code, bit_size, l, m, bits, range, sign;
342 mbMotionVectorTable[0][1],
343 mbMotionVectorTable[0][0]);
345 bit_size = s->f_code - 1;
346 range = 1 << bit_size;
347 /* modulo encoding */
352 } else if (val >= l) {
358 code = (val >> bit_size) + 1;
359 bits = val & (range - 1);
364 code = (val >> bit_size) + 1;
365 bits = val & (range - 1);
369 mbMotionVectorTable[code][1],
370 mbMotionVectorTable[code][0]);
371 put_bits(&s->pb, 1, sign);
373 put_bits(&s->pb, bit_size, bits);
378 void ff_mpeg1_encode_init(MpegEncContext *s)
394 mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
395 mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
398 /* build unified dc encoding tables */
399 for(i=-255; i<256; i++)
407 index = vlc_dc_table[adiff];
409 bits= vlc_dc_lum_bits[index] + index;
410 code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
411 mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
413 bits= vlc_dc_chroma_bits[index] + index;
414 code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
415 mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
418 for(f_code=1; f_code<=MAX_FCODE; f_code++){
419 for(mv=-MAX_MV; mv<=MAX_MV; mv++){
422 if(mv==0) len= mbMotionVectorTable[0][1];
424 int val, bit_size, range, code;
426 bit_size = s->f_code - 1;
427 range = 1 << bit_size;
433 code = (val >> bit_size) + 1;
435 len= mbMotionVectorTable[code][1] + 1 + bit_size;
437 len= mbMotionVectorTable[16][1] + 2 + bit_size;
441 mv_penalty[f_code][mv+MAX_MV]= len;
446 for(f_code=MAX_FCODE; f_code>0; f_code--){
447 for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
448 fcode_tab[mv+MAX_MV]= f_code;
452 s->mv_penalty= mv_penalty;
453 s->fcode_tab= fcode_tab;
456 s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
457 s->inter_quant_bias= 0;
460 static inline void encode_dc(MpegEncContext *s, int diff, int component)
462 if (component == 0) {
465 mpeg1_lum_dc_uni[diff+255]&0xFF,
466 mpeg1_lum_dc_uni[diff+255]>>8);
470 mpeg1_chr_dc_uni[diff+255]&0xFF,
471 mpeg1_chr_dc_uni[diff+255]>>8);
475 static void mpeg1_encode_block(MpegEncContext *s,
479 int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
481 // RLTable *rl = &rl_mpeg1;
483 last_index = s->block_last_index[n];
487 component = (n <= 3 ? 0 : n - 4 + 1);
488 dc = block[0]; /* overflow is impossible */
489 diff = dc - s->last_dc[component];
490 encode_dc(s, diff, component);
491 s->last_dc[component] = dc;
494 /* encode the first coefficient : needs to be done here because
495 it is handled slightly differently */
497 if (abs(level) == 1) {
498 code = ((UINT32)level >> 31); /* the sign bit */
499 put_bits(&s->pb, 2, code | 0x02);
508 /* now quantify & encode AC coefs */
509 last_non_zero = i - 1;
511 for(;i<=last_index;i++) {
512 j = zigzag_direct[i];
517 dprintf("level[%d]=%d\n", i, level);
519 /* encode using VLC */
521 run = i - last_non_zero - 1;
531 : "=&r" (alevel), "=&r" (sign)
542 // code = get_rl_index(rl, 0, run, alevel);
543 if (alevel > mpeg1_max_level[0][run])
546 code= mpeg1_index_run[0][run] + alevel - 1;
548 if (code < 111 /* rl->n */) {
549 /* store the vlc & sign at once */
550 put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
552 /* escape seems to be pretty rare <5% so i dont optimize it */
553 put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
554 /* escape: only clip in this case */
555 put_bits(&s->pb, 6, run);
557 put_bits(&s->pb, 8, level & 0xff);
560 put_bits(&s->pb, 16, 0x8001 + level + 255);
562 put_bits(&s->pb, 16, level & 0xffff);
570 put_bits(&s->pb, 2, 0x2);
573 /******************************************/
576 static VLC dc_lum_vlc;
577 static VLC dc_chroma_vlc;
579 static VLC mbincr_vlc;
580 static VLC mb_ptype_vlc;
581 static VLC mb_btype_vlc;
582 static VLC mb_pat_vlc;
584 void mpeg1_init_vlc(MpegEncContext *s)
591 init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12,
592 vlc_dc_lum_bits, 1, 1,
593 vlc_dc_lum_code, 2, 2);
594 init_vlc(&dc_chroma_vlc, DC_VLC_BITS, 12,
595 vlc_dc_chroma_bits, 1, 1,
596 vlc_dc_chroma_code, 2, 2);
597 init_vlc(&mv_vlc, MV_VLC_BITS, 17,
598 &mbMotionVectorTable[0][1], 2, 1,
599 &mbMotionVectorTable[0][0], 2, 1);
600 init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 35,
601 &mbAddrIncrTable[0][1], 2, 1,
602 &mbAddrIncrTable[0][0], 2, 1);
603 init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63,
604 &mbPatTable[0][1], 2, 1,
605 &mbPatTable[0][0], 2, 1);
607 init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 32,
608 &table_mb_ptype[0][1], 2, 1,
609 &table_mb_ptype[0][0], 2, 1);
610 init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 32,
611 &table_mb_btype[0][1], 2, 1,
612 &table_mb_btype[0][0], 2, 1);
616 init_2d_vlc_rl(&rl_mpeg1);
617 init_2d_vlc_rl(&rl_mpeg2);
621 static inline int get_dmv(MpegEncContext *s)
623 if(get_bits1(&s->gb))
624 return 1 - (get_bits1(&s->gb) << 1);
629 static inline int get_qscale(MpegEncContext *s)
633 if (s->q_scale_type) {
634 qscale = non_linear_qscale[get_bits(&s->gb, 5)];
636 qscale = get_bits(&s->gb, 5) << 1;
639 /* for mpeg1, we use the generic unquant code */
640 qscale = get_bits(&s->gb, 5);
645 /* motion type (for mpeg2) */
651 static int mpeg_decode_mb(MpegEncContext *s,
652 DCTELEM block[6][64])
654 int i, j, k, cbp, val, code, mb_type, motion_type;
656 /* skip mb handling */
657 if (s->mb_incr == 0) {
658 /* read again increment */
661 code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
663 return 1; /* error = end of slice */
668 /* otherwise, stuffing, nothing to do */
675 if(s->mb_x==-1 /* first MB in a slice */ && s->mb_incr>1){
676 s->mb_x+= (s->mb_incr - 1) % s->mb_width;
677 s->mb_y+= (s->mb_incr - 1) / s->mb_width;
681 if (++s->mb_x >= s->mb_width) {
683 if (s->mb_y >= (s->mb_height - 1)){
684 fprintf(stderr, "slice too long\n");
689 dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
691 if (--s->mb_incr != 0) {
695 s->block_last_index[i] = -1;
696 s->mv_type = MV_TYPE_16X16;
697 if (s->pict_type == P_TYPE) {
698 /* if P type, zero motion vector is implied */
699 s->mv_dir = MV_DIR_FORWARD;
700 s->mv[0][0][0] = s->mv[0][0][1] = 0;
701 s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
702 s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
704 /* if B type, reuse previous vectors and directions */
705 s->mv[0][0][0] = s->last_mv[0][0][0];
706 s->mv[0][0][1] = s->last_mv[0][0][1];
707 s->mv[1][0][0] = s->last_mv[1][0][0];
708 s->mv[1][0][1] = s->last_mv[1][0][1];
714 switch(s->pict_type) {
717 if (get_bits1(&s->gb) == 0) {
718 if (get_bits1(&s->gb) == 0)
720 mb_type = MB_QUANT | MB_INTRA;
726 mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
728 fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
733 mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
735 fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
740 dprintf("mb_type=%x\n", mb_type);
741 motion_type = 0; /* avoid warning */
742 if (mb_type & (MB_FOR|MB_BACK)) {
743 /* get additionnal motion vector type */
744 if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct)
745 motion_type = MT_FRAME;
747 motion_type = get_bits(&s->gb, 2);
749 /* compute dct type */
750 if (s->picture_structure == PICT_FRAME &&
751 !s->frame_pred_frame_dct &&
752 (mb_type & (MB_PAT | MB_INTRA))) {
753 s->interlaced_dct = get_bits1(&s->gb);
755 if (s->interlaced_dct)
756 printf("interlaced_dct\n");
759 s->interlaced_dct = 0; /* frame based */
762 if (mb_type & MB_QUANT) {
763 s->qscale = get_qscale(s);
765 if (mb_type & MB_INTRA) {
766 if (s->concealment_motion_vectors) {
767 /* just parse them */
768 if (s->picture_structure != PICT_FRAME)
769 skip_bits1(&s->gb); /* field select */
770 mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
771 mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
775 memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
780 /* special case of implicit zero motion vector */
781 if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
782 s->mv_dir = MV_DIR_FORWARD;
783 s->mv_type = MV_TYPE_16X16;
784 s->last_mv[0][0][0] = 0;
785 s->last_mv[0][0][1] = 0;
786 s->last_mv[0][1][0] = 0;
787 s->last_mv[0][1][1] = 0;
790 } else if (mb_type & (MB_FOR | MB_BACK)) {
794 if (mb_type & (MB_FOR >> i)) {
795 s->mv_dir |= (MV_DIR_FORWARD >> i);
796 dprintf("motion_type=%d\n", motion_type);
797 switch(motion_type) {
798 case MT_FRAME: /* or MT_16X8 */
799 if (s->picture_structure == PICT_FRAME) {
801 s->mv_type = MV_TYPE_16X16;
803 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
804 s->last_mv[i][0][k]);
805 s->last_mv[i][0][k] = val;
806 s->last_mv[i][1][k] = val;
807 /* full_pel: only for mpeg1 */
810 s->mv[i][0][k] = val;
811 dprintf("mv%d: %d\n", k, val);
815 s->mv_type = MV_TYPE_16X8;
817 s->field_select[i][j] = get_bits1(&s->gb);
819 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
820 s->last_mv[i][j][k]);
821 s->last_mv[i][j][k] = val;
822 s->mv[i][j][k] = val;
828 if (s->picture_structure == PICT_FRAME) {
829 s->mv_type = MV_TYPE_FIELD;
831 s->field_select[i][j] = get_bits1(&s->gb);
832 val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
833 s->last_mv[i][j][0]);
834 s->last_mv[i][j][0] = val;
835 s->mv[i][j][0] = val;
836 dprintf("fmx=%d\n", val);
837 val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
838 s->last_mv[i][j][1] >> 1);
839 s->last_mv[i][j][1] = val << 1;
840 s->mv[i][j][1] = val;
841 dprintf("fmy=%d\n", val);
844 s->mv_type = MV_TYPE_16X16;
845 s->field_select[i][0] = get_bits1(&s->gb);
847 val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
848 s->last_mv[i][0][k]);
849 s->last_mv[i][0][k] = val;
850 s->last_mv[i][1][k] = val;
851 s->mv[i][0][k] = val;
857 int dmx, dmy, mx, my, m;
859 mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
860 s->last_mv[i][0][0]);
861 s->last_mv[i][0][0] = mx;
862 s->last_mv[i][1][0] = mx;
864 my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
865 s->last_mv[i][0][1] >> 1);
867 s->mv_type = MV_TYPE_DMV;
868 /* XXX: totally broken */
869 if (s->picture_structure == PICT_FRAME) {
870 s->last_mv[i][0][1] = my << 1;
871 s->last_mv[i][1][1] = my << 1;
873 m = s->top_field_first ? 1 : 3;
874 /* top -> top pred */
876 s->mv[i][0][1] = my << 1;
877 s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
878 s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
881 s->mv[i][2][1] = my << 1;
882 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
883 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
885 s->last_mv[i][0][1] = my;
886 s->last_mv[i][1][1] = my;
889 s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
890 s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
891 /* + 2 * cur_field */;
900 if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
901 skip_bits1(&s->gb); /* marker */
904 if (mb_type & MB_PAT) {
905 cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
907 fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
912 dprintf("cbp=%x\n", cbp);
917 if (cbp & (1 << (5 - i))) {
918 if (mpeg2_decode_block_intra(s, block[i], i) < 0)
921 s->block_last_index[i] = -1;
926 if (cbp & (1 << (5 - i))) {
927 if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
930 s->block_last_index[i] = -1;
936 if (cbp & (1 << (5 - i))) {
937 if (mpeg1_decode_block(s, block[i], i) < 0)
940 s->block_last_index[i] = -1;
947 /* as h263, but only 17 codes */
948 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
950 int code, sign, val, m, l, shift;
952 code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
959 sign = get_bits1(&s->gb);
961 val = (code - 1) << shift;
963 val |= get_bits(&s->gb, shift);
969 /* modulo decoding */
970 l = (1 << shift) * 16;
974 } else if (val >= l) {
980 static inline int decode_dc(MpegEncContext *s, int component)
984 if (component == 0) {
985 code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
987 code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
990 fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
996 diff = get_bits(&s->gb, code);
997 if ((diff & (1 << (code - 1))) == 0)
998 diff = (-1 << code) | (diff + 1);
1003 static int mpeg1_decode_block(MpegEncContext *s,
1007 int level, dc, diff, i, j, run;
1008 int code, component;
1009 RLTable *rl = &rl_mpeg1;
1013 component = (n <= 3 ? 0 : n - 4 + 1);
1014 diff = decode_dc(s, component);
1017 dc = s->last_dc[component];
1019 s->last_dc[component] = dc;
1021 dprintf("dc=%d diff=%d\n", dc, diff);
1025 OPEN_READER(re, &s->gb);
1027 /* special case for the first coef. no need to add a second vlc table */
1028 UPDATE_CACHE(re, &s->gb);
1029 v= SHOW_UBITS(re, &s->gb, 2);
1032 level = 1 - ((v & 1) << 1);
1033 SKIP_BITS(re, &s->gb, 2);
1034 CLOSE_READER(re, &s->gb);
1037 CLOSE_READER(re, &s->gb);
1040 /* now quantify & encode AC coefs */
1042 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1048 } else if (code == 111) {
1050 run = get_bits(&s->gb, 6);
1051 level = get_bits(&s->gb, 8);
1052 level= (level + ((-1)<<7)) ^ ((-1)<<7); //sign extension
1053 if (level == -128) {
1054 level = get_bits(&s->gb, 8) - 256;
1055 } else if (level == 0) {
1056 level = get_bits(&s->gb, 8);
1059 run = rl->table_run[code];
1060 level = rl->table_level[code];
1061 if (get_bits1(&s->gb))
1068 dprintf("%d: run=%d level=%d\n", n, run, level);
1069 j = zigzag_direct[i];
1073 s->block_last_index[n] = i-1;
1077 /* Also does unquantization here, since I will never support mpeg2
1079 static int mpeg2_decode_block_non_intra(MpegEncContext *s,
1083 int level, i, j, run;
1085 RLTable *rl = &rl_mpeg1;
1086 const UINT8 *scan_table;
1087 const UINT16 *matrix;
1090 if (s->alternate_scan)
1091 scan_table = ff_alternate_vertical_scan;
1093 scan_table = zigzag_direct;
1098 OPEN_READER(re, &s->gb);
1101 matrix = s->inter_matrix;
1103 matrix = s->chroma_inter_matrix;
1105 /* special case for the first coef. no need to add a second vlc table */
1106 UPDATE_CACHE(re, &s->gb);
1107 v= SHOW_UBITS(re, &s->gb, 2);
1110 level = 1 - ((v & 1) << 1);
1111 SKIP_BITS(re, &s->gb, 2);
1112 CLOSE_READER(re, &s->gb);
1115 CLOSE_READER(re, &s->gb);
1118 /* now quantify & encode AC coefs */
1120 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1122 fprintf(stderr, "invalid ac code at %d %d\n", s->mb_x, s->mb_y);
1127 } else if (code == 111) {
1129 run = get_bits(&s->gb, 6);
1130 level = get_bits(&s->gb, 12);
1131 level= (level + ((-1)<<11)) ^ ((-1)<<11); //sign extension
1133 run = rl->table_run[code];
1134 level = rl->table_level[code];
1135 if (get_bits1(&s->gb))
1140 fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
1145 dprintf("%d: run=%d level=%d\n", n, run, level);
1148 level = ((level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1150 level = ((-level * 2 + 1) * s->qscale * matrix[j]) >> 5;
1153 /* XXX: is it really necessary to saturate since the encoder
1154 knows whats going on ? */
1159 block[63] ^= (mismatch & 1);
1160 s->block_last_index[n] = i;
1164 static int mpeg2_decode_block_intra(MpegEncContext *s,
1168 int level, dc, diff, i, j, run;
1169 int code, component;
1171 const UINT8 *scan_table;
1172 const UINT16 *matrix;
1175 if (s->alternate_scan)
1176 scan_table = ff_alternate_vertical_scan;
1178 scan_table = zigzag_direct;
1181 component = (n <= 3 ? 0 : n - 4 + 1);
1182 diff = decode_dc(s, component);
1185 dc = s->last_dc[component];
1187 s->last_dc[component] = dc;
1188 block[0] = dc << (3 - s->intra_dc_precision);
1189 dprintf("dc=%d\n", block[0]);
1190 mismatch = block[0] ^ 1;
1192 if (s->intra_vlc_format)
1197 matrix = s->intra_matrix;
1199 matrix = s->chroma_intra_matrix;
1201 /* now quantify & encode AC coefs */
1203 code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
1205 fprintf(stderr, "invalid ac code at %d %d\n", s->mb_x, s->mb_y);
1210 } else if (code == 111) {
1212 run = get_bits(&s->gb, 6);
1213 level = get_bits(&s->gb, 12);
1214 level= (level + ((-1)<<11)) ^ ((-1)<<11); //sign extension
1216 run = rl->table_run[code];
1217 level = rl->table_level[code];
1218 if (get_bits1(&s->gb))
1223 fprintf(stderr, "run too long at %d %d\n", s->mb_x, s->mb_y);
1227 dprintf("%d: run=%d level=%d\n", n, run, level);
1228 level = (level * s->qscale * matrix[j]) / 16;
1229 /* XXX: is it really necessary to saturate since the encoder
1230 knows whats going on ? */
1235 block[63] ^= (mismatch & 1);
1236 s->block_last_index[n] = i;
1240 /* compressed picture size */
1241 #define PICTURE_BUFFER_SIZE 100000
1243 typedef struct Mpeg1Context {
1244 MpegEncContext mpeg_enc_ctx;
1245 UINT32 header_state;
1246 int start_code; /* current start code */
1247 UINT8 buffer[PICTURE_BUFFER_SIZE];
1250 int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
1251 int repeat_field; /* true if we must repeat the field */
1254 static int mpeg_decode_init(AVCodecContext *avctx)
1256 Mpeg1Context *s = avctx->priv_data;
1258 s->mpeg_enc_ctx.flags= avctx->flags;
1259 common_init(&s->mpeg_enc_ctx);
1261 s->header_state = 0xff;
1262 s->mpeg_enc_ctx_allocated = 0;
1263 s->buffer_size = PICTURE_BUFFER_SIZE;
1265 s->buf_ptr = s->buffer;
1266 s->mpeg_enc_ctx.picture_number = 0;
1267 s->repeat_field = 0;
1268 s->mpeg_enc_ctx.codec_id= avctx->codec->id;
1269 avctx->mbskip_table= s->mpeg_enc_ctx.mbskip_table;
1273 /* return the 8 bit start code value and update the search
1274 state. Return -1 if no start code found */
1275 static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end,
1276 UINT32 *header_state)
1279 unsigned int state, v;
1282 state = *header_state;
1283 buf_ptr = *pbuf_ptr;
1284 while (buf_ptr < buf_end) {
1286 if (state == 0x000001) {
1287 state = ((state << 8) | v) & 0xffffff;
1291 state = ((state << 8) | v) & 0xffffff;
1295 *pbuf_ptr = buf_ptr;
1296 *header_state = state;
1300 static int mpeg1_decode_picture(AVCodecContext *avctx,
1301 UINT8 *buf, int buf_size)
1303 Mpeg1Context *s1 = avctx->priv_data;
1304 MpegEncContext *s = &s1->mpeg_enc_ctx;
1307 init_get_bits(&s->gb, buf, buf_size);
1309 ref = get_bits(&s->gb, 10); /* temporal ref */
1310 s->pict_type = get_bits(&s->gb, 3);
1311 dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
1312 skip_bits(&s->gb, 16);
1313 if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
1314 s->full_pel[0] = get_bits1(&s->gb);
1315 f_code = get_bits(&s->gb, 3);
1318 s->mpeg_f_code[0][0] = f_code;
1319 s->mpeg_f_code[0][1] = f_code;
1321 if (s->pict_type == B_TYPE) {
1322 s->full_pel[1] = get_bits1(&s->gb);
1323 f_code = get_bits(&s->gb, 3);
1326 s->mpeg_f_code[1][0] = f_code;
1327 s->mpeg_f_code[1][1] = f_code;
1335 static void mpeg_decode_sequence_extension(MpegEncContext *s)
1337 int horiz_size_ext, vert_size_ext;
1338 int bit_rate_ext, vbv_buf_ext, low_delay;
1339 int frame_rate_ext_n, frame_rate_ext_d;
1341 skip_bits(&s->gb, 8); /* profil and level */
1342 s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
1343 skip_bits(&s->gb, 2); /* chroma_format */
1344 horiz_size_ext = get_bits(&s->gb, 2);
1345 vert_size_ext = get_bits(&s->gb, 2);
1346 s->width |= (horiz_size_ext << 12);
1347 s->height |= (vert_size_ext << 12);
1348 bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */
1349 s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
1350 skip_bits1(&s->gb); /* marker */
1351 vbv_buf_ext = get_bits(&s->gb, 8);
1352 low_delay = get_bits1(&s->gb);
1353 frame_rate_ext_n = get_bits(&s->gb, 2);
1354 frame_rate_ext_d = get_bits(&s->gb, 5);
1355 if (frame_rate_ext_d >= 1)
1356 s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
1357 dprintf("sequence extension\n");
1359 s->avctx->sub_id = 2; /* indicates mpeg2 found */
1362 static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
1366 dprintf("matrix extension\n");
1368 if (get_bits1(&s->gb)) {
1370 v = get_bits(&s->gb, 8);
1371 j = zigzag_direct[i];
1372 s->intra_matrix[j] = v;
1373 s->chroma_intra_matrix[j] = v;
1376 if (get_bits1(&s->gb)) {
1378 v = get_bits(&s->gb, 8);
1379 j = zigzag_direct[i];
1380 s->inter_matrix[j] = v;
1381 s->chroma_inter_matrix[j] = v;
1384 if (get_bits1(&s->gb)) {
1386 v = get_bits(&s->gb, 8);
1387 j = zigzag_direct[i];
1388 s->chroma_intra_matrix[j] = v;
1391 if (get_bits1(&s->gb)) {
1393 v = get_bits(&s->gb, 8);
1394 j = zigzag_direct[i];
1395 s->chroma_inter_matrix[j] = v;
1400 static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
1402 s->full_pel[0] = s->full_pel[1] = 0;
1403 s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
1404 s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
1405 s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
1406 s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
1407 s->intra_dc_precision = get_bits(&s->gb, 2);
1408 s->picture_structure = get_bits(&s->gb, 2);
1409 s->top_field_first = get_bits1(&s->gb);
1410 s->frame_pred_frame_dct = get_bits1(&s->gb);
1411 s->concealment_motion_vectors = get_bits1(&s->gb);
1412 s->q_scale_type = get_bits1(&s->gb);
1413 s->intra_vlc_format = get_bits1(&s->gb);
1414 s->alternate_scan = get_bits1(&s->gb);
1415 s->repeat_first_field = get_bits1(&s->gb);
1416 s->chroma_420_type = get_bits1(&s->gb);
1417 s->progressive_frame = get_bits1(&s->gb);
1418 /* composite display not parsed */
1419 dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
1420 dprintf("picture_structure=%d\n", s->picture_structure);
1421 dprintf("top field first=%d\n", s->top_field_first);
1422 dprintf("repeat first field=%d\n", s->repeat_first_field);
1423 dprintf("conceal=%d\n", s->concealment_motion_vectors);
1424 dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
1425 dprintf("alternate_scan=%d\n", s->alternate_scan);
1426 dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
1427 dprintf("progressive_frame=%d\n", s->progressive_frame);
1430 static void mpeg_decode_extension(AVCodecContext *avctx,
1431 UINT8 *buf, int buf_size)
1433 Mpeg1Context *s1 = avctx->priv_data;
1434 MpegEncContext *s = &s1->mpeg_enc_ctx;
1437 init_get_bits(&s->gb, buf, buf_size);
1439 ext_type = get_bits(&s->gb, 4);
1443 mpeg_decode_sequence_extension(s);
1446 /* quant matrix extension */
1447 mpeg_decode_quant_matrix_extension(s);
1450 /* picture extension */
1451 mpeg_decode_picture_coding_extension(s);
1456 /* return 1 if end of frame */
1457 static int mpeg_decode_slice(AVCodecContext *avctx,
1460 UINT8 *buf, int buf_size)
1462 Mpeg1Context *s1 = avctx->priv_data;
1463 MpegEncContext *s = &s1->mpeg_enc_ctx;
1466 start_code = (start_code - 1) & 0xff;
1467 if (start_code >= s->mb_height){
1468 fprintf(stderr, "slice below image\n");
1471 s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
1472 s->last_dc[1] = s->last_dc[0];
1473 s->last_dc[2] = s->last_dc[0];
1474 memset(s->last_mv, 0, sizeof(s->last_mv));
1476 s->mb_y = start_code;
1478 /* start frame decoding */
1479 if (s->first_slice) {
1481 MPV_frame_start(s, avctx);
1484 init_get_bits(&s->gb, buf, buf_size);
1486 s->qscale = get_qscale(s);
1487 /* extra slice info */
1488 while (get_bits1(&s->gb) != 0) {
1489 skip_bits(&s->gb, 8);
1493 clear_blocks(s->block[0]);
1495 ret = mpeg_decode_mb(s, s->block);
1496 dprintf("ret=%d\n", ret);
1501 MPV_decode_mb(s, s->block);
1505 /* end of slice reached */
1506 if (s->mb_x == (s->mb_width - 1) &&
1507 s->mb_y == (s->mb_height - 1)) {
1513 /* XXX: incorrect reported qscale for mpeg2 */
1514 if (s->pict_type == B_TYPE) {
1515 picture = s->current_picture;
1516 avctx->quality = s->qscale;
1518 /* latency of 1 frame for I and P frames */
1519 /* XXX: use another variable than picture_number */
1520 if (s->picture_number == 0) {
1523 picture = s->last_picture;
1524 avctx->quality = s->last_qscale;
1526 s->last_qscale = s->qscale;
1527 s->picture_number++;
1530 pict->data[0] = picture[0];
1531 pict->data[1] = picture[1];
1532 pict->data[2] = picture[2];
1533 pict->linesize[0] = s->linesize;
1534 pict->linesize[1] = s->uvlinesize;
1535 pict->linesize[2] = s->uvlinesize;
1545 static int mpeg1_decode_sequence(AVCodecContext *avctx,
1546 UINT8 *buf, int buf_size)
1548 Mpeg1Context *s1 = avctx->priv_data;
1549 MpegEncContext *s = &s1->mpeg_enc_ctx;
1550 int width, height, i, v, j;
1552 init_get_bits(&s->gb, buf, buf_size);
1554 width = get_bits(&s->gb, 12);
1555 height = get_bits(&s->gb, 12);
1556 skip_bits(&s->gb, 4);
1557 s->frame_rate_index = get_bits(&s->gb, 4);
1558 if (s->frame_rate_index == 0)
1560 s->bit_rate = get_bits(&s->gb, 18) * 400;
1561 if (get_bits1(&s->gb) == 0) /* marker */
1563 if (width <= 0 || height <= 0 ||
1564 (width % 2) != 0 || (height % 2) != 0)
1566 if (width != s->width ||
1567 height != s->height) {
1568 /* start new mpeg1 context decoding */
1569 s->out_format = FMT_MPEG1;
1570 if (s1->mpeg_enc_ctx_allocated) {
1575 avctx->has_b_frames= s->has_b_frames = 1;
1577 avctx->width = width;
1578 avctx->height = height;
1579 if (s->frame_rate_index >= 9) {
1580 /* at least give a valid frame rate (some old mpeg1 have this) */
1581 avctx->frame_rate = 25 * FRAME_RATE_BASE;
1583 avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
1585 s->frame_rate = avctx->frame_rate;
1586 avctx->bit_rate = s->bit_rate;
1588 if (MPV_common_init(s) < 0)
1591 s1->mpeg_enc_ctx_allocated = 1;
1594 skip_bits(&s->gb, 10); /* vbv_buffer_size */
1595 skip_bits(&s->gb, 1);
1598 if (get_bits1(&s->gb)) {
1600 v = get_bits(&s->gb, 8);
1601 j = zigzag_direct[i];
1602 s->intra_matrix[j] = v;
1603 s->chroma_intra_matrix[j] = v;
1606 dprintf("intra matrix present\n");
1608 dprintf(" %d", s->intra_matrix[zigzag_direct[i]]);
1613 v = ff_mpeg1_default_intra_matrix[i];
1614 s->intra_matrix[i] = v;
1615 s->chroma_intra_matrix[i] = v;
1618 if (get_bits1(&s->gb)) {
1620 v = get_bits(&s->gb, 8);
1621 j = zigzag_direct[i];
1622 s->inter_matrix[j] = v;
1623 s->chroma_inter_matrix[j] = v;
1626 dprintf("non intra matrix present\n");
1628 dprintf(" %d", s->inter_matrix[zigzag_direct[i]]);
1633 v = ff_mpeg1_default_non_intra_matrix[i];
1634 s->inter_matrix[i] = v;
1635 s->chroma_inter_matrix[i] = v;
1639 /* we set mpeg2 parameters so that it emulates mpeg1 */
1640 s->progressive_sequence = 1;
1641 s->progressive_frame = 1;
1642 s->picture_structure = PICT_FRAME;
1643 s->frame_pred_frame_dct = 1;
1645 avctx->sub_id = 1; /* indicates mpeg1 */
1649 /* handle buffering and image synchronisation */
1650 static int mpeg_decode_frame(AVCodecContext *avctx,
1651 void *data, int *data_size,
1652 UINT8 *buf, int buf_size)
1654 Mpeg1Context *s = avctx->priv_data;
1655 UINT8 *buf_end, *buf_ptr, *buf_start;
1656 int len, start_code_found, ret, code, start_code, input_size;
1657 AVPicture *picture = data;
1658 MpegEncContext *s2 = &s->mpeg_enc_ctx;
1660 dprintf("fill_buffer\n");
1664 /* special case for last picture */
1665 if (buf_size == 0) {
1666 if (s2->picture_number > 0) {
1667 picture->data[0] = s2->next_picture[0];
1668 picture->data[1] = s2->next_picture[1];
1669 picture->data[2] = s2->next_picture[2];
1670 picture->linesize[0] = s2->linesize;
1671 picture->linesize[1] = s2->uvlinesize;
1672 picture->linesize[2] = s2->uvlinesize;
1673 *data_size = sizeof(AVPicture);
1679 buf_end = buf + buf_size;
1682 if (s->repeat_field % 2 == 1) {
1684 //fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
1685 // s2->picture_number, s->repeat_field);
1686 if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
1687 *data_size = sizeof(AVPicture);
1692 while (buf_ptr < buf_end) {
1693 buf_start = buf_ptr;
1694 /* find start next code */
1695 code = find_start_code(&buf_ptr, buf_end, &s->header_state);
1697 start_code_found = 1;
1699 start_code_found = 0;
1701 /* copy to buffer */
1702 len = buf_ptr - buf_start;
1703 if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
1704 /* data too big : flush */
1705 s->buf_ptr = s->buffer;
1706 if (start_code_found)
1707 s->start_code = code;
1709 memcpy(s->buf_ptr, buf_start, len);
1712 if (start_code_found) {
1713 /* prepare data for next start code */
1714 input_size = s->buf_ptr - s->buffer;
1715 start_code = s->start_code;
1716 s->buf_ptr = s->buffer;
1717 s->start_code = code;
1718 switch(start_code) {
1719 case SEQ_START_CODE:
1720 mpeg1_decode_sequence(avctx, s->buffer,
1724 case PICTURE_START_CODE:
1725 /* we have a complete image : we try to decompress it */
1726 mpeg1_decode_picture(avctx,
1727 s->buffer, input_size);
1729 case EXT_START_CODE:
1730 mpeg_decode_extension(avctx,
1731 s->buffer, input_size);
1734 if (start_code >= SLICE_MIN_START_CODE &&
1735 start_code <= SLICE_MAX_START_CODE) {
1736 ret = mpeg_decode_slice(avctx, picture,
1737 start_code, s->buffer, input_size);
1739 /* got a picture: exit */
1740 /* first check if we must repeat the frame */
1741 avctx->repeat_pict = 0;
1743 if (s2->progressive_frame && s2->repeat_first_field) {
1744 //fprintf(stderr,"\nRepeat this frame: %d! pict: %d",avctx->frame_number,s2->picture_number);
1745 //s2->repeat_first_field = 0;
1746 //s2->progressive_frame = 0;
1747 if (++s->repeat_field > 2)
1748 s->repeat_field = 0;
1749 avctx->repeat_pict = 1;
1752 if (s2->repeat_first_field) {
1753 if (s2->progressive_sequence) {
1754 if (s2->top_field_first)
1755 avctx->repeat_pict = 4;
1757 avctx->repeat_pict = 2;
1758 } else if (s2->progressive_frame) {
1759 avctx->repeat_pict = 1;
1762 *data_size = sizeof(AVPicture);
1765 printf("Error while decoding slice\n");
1774 return buf_ptr - buf;
1777 static int mpeg_decode_end(AVCodecContext *avctx)
1779 Mpeg1Context *s = avctx->priv_data;
1781 if (s->mpeg_enc_ctx_allocated)
1782 MPV_common_end(&s->mpeg_enc_ctx);
1786 AVCodec mpeg_decoder = {
1789 CODEC_ID_MPEG1VIDEO,
1790 sizeof(Mpeg1Context),