3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 #include "mpegvideo.h"
33 #define H261_MBA_VLC_BITS 9
34 #define H261_MTYPE_VLC_BITS 6
35 #define H261_MV_VLC_BITS 7
36 #define H261_CBP_VLC_BITS 9
37 #define TCOEFF_VLC_BITS 9
39 #define MBA_STUFFING 33
40 #define MBA_STARTCODE 34
41 #define IS_FIL(a) ((a)&MB_TYPE_H261_FIL)
46 typedef struct H261Context{
56 int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read
59 void ff_h261_loop_filter(MpegEncContext *s){
60 H261Context * h= (H261Context*)s;
61 const int linesize = s->linesize;
62 const int uvlinesize= s->uvlinesize;
63 uint8_t *dest_y = s->dest[0];
64 uint8_t *dest_cb= s->dest[1];
65 uint8_t *dest_cr= s->dest[2];
67 if(!(IS_FIL (h->mtype)))
70 s->dsp.h261_loop_filter(dest_y , linesize);
71 s->dsp.h261_loop_filter(dest_y + 8, linesize);
72 s->dsp.h261_loop_filter(dest_y + 8 * linesize , linesize);
73 s->dsp.h261_loop_filter(dest_y + 8 * linesize + 8, linesize);
74 s->dsp.h261_loop_filter(dest_cb, uvlinesize);
75 s->dsp.h261_loop_filter(dest_cr, uvlinesize);
78 static int ff_h261_get_picture_format(int width, int height){
80 if (width == 176 && height == 144)
83 else if (width == 352 && height == 288)
90 static void h261_encode_block(H261Context * h, DCTELEM * block,
92 static int h261_decode_block(H261Context *h, DCTELEM *block,
95 void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){
96 H261Context * h = (H261Context *) s;
99 align_put_bits(&s->pb);
101 /* Update the pointer to last GOB */
102 s->ptr_lastgob = pbBufPtr(&s->pb);
104 put_bits(&s->pb, 20, 0x10); /* PSC */
106 temp_ref= s->picture_number * (int64_t)30000 * s->avctx->time_base.num /
107 (1001 * (int64_t)s->avctx->time_base.den); //FIXME maybe this should use a timestamp
108 put_bits(&s->pb, 5, temp_ref & 0x1f); /* TemporalReference */
110 put_bits(&s->pb, 1, 0); /* split screen off */
111 put_bits(&s->pb, 1, 0); /* camera off */
112 put_bits(&s->pb, 1, 0); /* freeze picture release off */
114 format = ff_h261_get_picture_format(s->width, s->height);
116 put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */
118 put_bits(&s->pb, 1, 0); /* still image mode */
119 put_bits(&s->pb, 1, 0); /* reserved */
121 put_bits(&s->pb, 1, 0); /* no PEI */
130 * Encodes a group of blocks header.
132 static void h261_encode_gob_header(MpegEncContext * s, int mb_line){
133 H261Context * h = (H261Context *)s;
134 if(ff_h261_get_picture_format(s->width, s->height) == 0){
135 h->gob_number+=2; // QCIF
138 h->gob_number++; // CIF
140 put_bits(&s->pb, 16, 1); /* GBSC */
141 put_bits(&s->pb, 4, h->gob_number); /* GN */
142 put_bits(&s->pb, 5, s->qscale); /* GQUANT */
143 put_bits(&s->pb, 1, 0); /* no GEI */
150 void ff_h261_reorder_mb_index(MpegEncContext* s){
151 int index= s->mb_x + s->mb_y*s->mb_width;
154 h261_encode_gob_header(s,0);
156 /* for CIF the GOB's are fragmented in the middle of a scanline
157 that's why we need to adjust the x and y index of the macroblocks */
158 if(ff_h261_get_picture_format(s->width,s->height) == 1){ // CIF
159 s->mb_x = index % 11 ; index /= 11;
160 s->mb_y = index % 3 ; index /= 3;
161 s->mb_x+= 11*(index % 2); index /= 2;
164 ff_init_block_index(s);
165 ff_update_block_index(s);
169 static void h261_encode_motion(H261Context * h, int val){
170 MpegEncContext * const s = &h->s;
174 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
182 code = sign ? -val : val;
183 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
184 put_bits(&s->pb,1,sign);
188 static inline int get_cbp(MpegEncContext * s,
189 DCTELEM block[6][64])
193 for (i = 0; i < 6; i++) {
194 if (s->block_last_index[i] >= 0)
199 void ff_h261_encode_mb(MpegEncContext * s,
200 DCTELEM block[6][64],
201 int motion_x, int motion_y)
203 H261Context * h = (H261Context *)s;
204 int mvd, mv_diff_x, mv_diff_y, i, cbp;
205 cbp = 63; // avoid warning
213 cbp= get_cbp(s, block);
215 /* mvd indicates if this block is motion compensated */
216 mvd = motion_x | motion_y;
218 if((cbp | mvd | s->dquant ) == 0) {
219 /* skip macroblock */
227 /* MB is not skipped, encode MBA */
228 put_bits(&s->pb, h261_mba_bits[(h->current_mba-h->previous_mba)-1], h261_mba_code[(h->current_mba-h->previous_mba)-1]);
230 /* calculate MTYPE */
234 if(mvd || s->loop_filter)
240 assert(h->mtype > 1);
246 put_bits(&s->pb, h261_mtype_bits[h->mtype], h261_mtype_code[h->mtype]);
248 h->mtype = h261_mtype_map[h->mtype];
250 if(IS_QUANT(h->mtype)){
251 ff_set_qscale(s,s->qscale+s->dquant);
252 put_bits(&s->pb, 5, s->qscale);
255 if(IS_16X16(h->mtype)){
256 mv_diff_x = (motion_x >> 1) - h->current_mv_x;
257 mv_diff_y = (motion_y >> 1) - h->current_mv_y;
258 h->current_mv_x = (motion_x >> 1);
259 h->current_mv_y = (motion_y >> 1);
260 h261_encode_motion(h,mv_diff_x);
261 h261_encode_motion(h,mv_diff_y);
264 h->previous_mba = h->current_mba;
266 if(HAS_CBP(h->mtype)){
267 put_bits(&s->pb,h261_cbp_tab[cbp-1][1],h261_cbp_tab[cbp-1][0]);
270 /* encode each block */
271 h261_encode_block(h, block[i], i);
274 if ( ( h->current_mba == 11 ) || ( h->current_mba == 22 ) || ( h->current_mba == 33 ) || ( !IS_16X16 ( h->mtype ) )){
280 void ff_h261_encode_init(MpegEncContext *s){
285 init_rl(&h261_rl_tcoeff, 1);
291 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
296 * encodes a 8x8 block.
297 * @param block the 8x8 block
298 * @param n block index (0-3 are luma, 4-5 are chroma)
300 static void h261_encode_block(H261Context * h, DCTELEM * block, int n){
301 MpegEncContext * const s = &h->s;
302 int level, run, last, i, j, last_index, last_non_zero, sign, slevel, code;
305 rl = &h261_rl_tcoeff;
309 /* 255 cannot be represented, so we clamp */
314 /* 0 cannot be represented also */
315 else if (level < 1) {
320 put_bits(&s->pb, 8, 0xff);
322 put_bits(&s->pb, 8, level);
324 } else if((block[0]==1 || block[0] == -1) && (s->block_last_index[n] > -1)){
326 put_bits(&s->pb,2,block[0]>0 ? 2 : 3 );
333 last_index = s->block_last_index[n];
334 last_non_zero = i - 1;
335 for (; i <= last_index; i++) {
336 j = s->intra_scantable.permutated[i];
339 run = i - last_non_zero - 1;
340 last = (i == last_index);
347 code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/, run, level);
348 if(run==0 && level < 16)
350 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
352 put_bits(&s->pb, 6, run);
354 assert(level <= 127);
355 put_bits(&s->pb, 8, slevel & 0xff);
357 put_bits(&s->pb, 1, sign);
363 put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]);// END OF BLOCK
367 /***********************************************/
370 static VLC h261_mba_vlc;
371 static VLC h261_mtype_vlc;
372 static VLC h261_mv_vlc;
373 static VLC h261_cbp_vlc;
375 void init_vlc_rl(RLTable *rl, int use_static);
377 static void h261_decode_init_vlc(H261Context *h){
382 init_vlc(&h261_mba_vlc, H261_MBA_VLC_BITS, 35,
384 h261_mba_code, 1, 1, 1);
385 init_vlc(&h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
386 h261_mtype_bits, 1, 1,
387 h261_mtype_code, 1, 1, 1);
388 init_vlc(&h261_mv_vlc, H261_MV_VLC_BITS, 17,
389 &h261_mv_tab[0][1], 2, 1,
390 &h261_mv_tab[0][0], 2, 1, 1);
391 init_vlc(&h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
392 &h261_cbp_tab[0][1], 2, 1,
393 &h261_cbp_tab[0][0], 2, 1, 1);
394 init_rl(&h261_rl_tcoeff, 1);
395 init_vlc_rl(&h261_rl_tcoeff, 1);
399 static int h261_decode_init(AVCodecContext *avctx){
400 H261Context *h= avctx->priv_data;
401 MpegEncContext * const s = &h->s;
404 MPV_decode_defaults(s);
407 s->width = s->avctx->coded_width;
408 s->height = s->avctx->coded_height;
409 s->codec_id = s->avctx->codec->id;
411 s->out_format = FMT_H261;
413 avctx->pix_fmt= PIX_FMT_YUV420P;
415 s->codec_id= avctx->codec->id;
417 h261_decode_init_vlc(h);
419 h->gob_start_code_skipped = 0;
425 * decodes the group of blocks header or slice header.
426 * @return <0 if an error occured
428 static int h261_decode_gob_header(H261Context *h){
430 MpegEncContext * const s = &h->s;
432 if ( !h->gob_start_code_skipped ){
433 /* Check for GOB Start Code */
434 val = show_bits(&s->gb, 15);
439 skip_bits(&s->gb, 16);
442 h->gob_start_code_skipped = 0;
444 h->gob_number = get_bits(&s->gb, 4); /* GN */
445 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
447 /* Check if gob_number is valid */
448 if (s->mb_height==18){ //cif
449 if ((h->gob_number<=0) || (h->gob_number>12))
453 if ((h->gob_number!=1) && (h->gob_number!=3) && (h->gob_number!=5))
458 while (get_bits1(&s->gb) != 0) {
459 skip_bits(&s->gb, 8);
465 // For the first transmitted macroblock in a GOB, MBA is the absolute address. For
466 // subsequent macroblocks, MBA is the difference between the absolute addresses of
467 // the macroblock and the last transmitted macroblock.
475 * decodes the group of blocks / video packet header.
476 * @return <0 if no resync found
478 static int ff_h261_resync(H261Context *h){
479 MpegEncContext * const s = &h->s;
482 if ( h->gob_start_code_skipped ){
483 ret= h261_decode_gob_header(h);
488 if(show_bits(&s->gb, 15)==0){
489 ret= h261_decode_gob_header(h);
493 //ok, its not where its supposed to be ...
494 s->gb= s->last_resync_gb;
495 align_get_bits(&s->gb);
496 left= s->gb.size_in_bits - get_bits_count(&s->gb);
498 for(;left>15+1+4+5; left-=8){
499 if(show_bits(&s->gb, 15)==0){
500 GetBitContext bak= s->gb;
502 ret= h261_decode_gob_header(h);
508 skip_bits(&s->gb, 8);
516 * decodes skipped macroblocks
519 static int h261_decode_mb_skipped(H261Context *h, int mba1, int mba2 )
521 MpegEncContext * const s = &h->s;
526 for(i=mba1; i<mba2; i++){
529 s->mb_x= ((h->gob_number-1) % 2) * 11 + i % 11;
530 s->mb_y= ((h->gob_number-1) / 2) * 3 + i / 11;
531 xy = s->mb_x + s->mb_y * s->mb_stride;
532 ff_init_block_index(s);
533 ff_update_block_index(s);
536 s->block_last_index[j] = -1;
538 s->mv_dir = MV_DIR_FORWARD;
539 s->mv_type = MV_TYPE_16X16;
540 s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
544 h->mtype &= ~MB_TYPE_H261_FIL;
546 MPV_decode_mb(s, s->block);
552 static int decode_mv_component(GetBitContext *gb, int v){
553 int mv_diff = get_vlc2(gb, h261_mv_vlc.table, H261_MV_VLC_BITS, 2);
555 /* check if mv_diff is valid */
559 mv_diff = mvmap[mv_diff];
561 if(mv_diff && !get_bits1(gb))
566 else if(v >= 16) v-= 32;
571 static int h261_decode_mb(H261Context *h){
572 MpegEncContext * const s = &h->s;
578 h->mba_diff = get_vlc2(&s->gb, h261_mba_vlc.table, H261_MBA_VLC_BITS, 2);
580 /* Check for slice end */
581 /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */
582 if (h->mba_diff == MBA_STARTCODE){ // start code
583 h->gob_start_code_skipped = 1;
587 while( h->mba_diff == MBA_STUFFING ); // stuffing
589 if ( h->mba_diff < 0 ){
590 if ( get_bits_count(&s->gb) + 7 >= s->gb.size_in_bits )
593 av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y);
598 h->current_mba += h->mba_diff;
600 if ( h->current_mba > MBA_STUFFING )
603 s->mb_x= ((h->gob_number-1) % 2) * 11 + ((h->current_mba-1) % 11);
604 s->mb_y= ((h->gob_number-1) / 2) * 3 + ((h->current_mba-1) / 11);
605 xy = s->mb_x + s->mb_y * s->mb_stride;
606 ff_init_block_index(s);
607 ff_update_block_index(s);
610 h->mtype = get_vlc2(&s->gb, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2);
611 h->mtype = h261_mtype_map[h->mtype];
614 if ( IS_QUANT ( h->mtype ) ){
615 ff_set_qscale(s, get_bits(&s->gb, 5));
618 s->mb_intra = IS_INTRA4x4(h->mtype);
621 if ( IS_16X16 ( h->mtype ) ){
622 // Motion vector data is included for all MC macroblocks. MVD is obtained from the macroblock vector by subtracting the
623 // vector of the preceding macroblock. For this calculation the vector of the preceding macroblock is regarded as zero in the
624 // following three situations:
625 // 1) evaluating MVD for macroblocks 1, 12 and 23;
626 // 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1;
627 // 3) MTYPE of the previous macroblock was not MC.
628 if ( ( h->current_mba == 1 ) || ( h->current_mba == 12 ) || ( h->current_mba == 23 ) ||
635 h->current_mv_x= decode_mv_component(&s->gb, h->current_mv_x);
636 h->current_mv_y= decode_mv_component(&s->gb, h->current_mv_y);
643 if ( HAS_CBP( h->mtype ) ){
644 cbp = get_vlc2(&s->gb, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1;
648 s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
653 s->mv_dir = MV_DIR_FORWARD;
654 s->mv_type = MV_TYPE_16X16;
655 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
656 s->mv[0][0][0] = h->current_mv_x * 2;//gets divided by 2 in motion compensation
657 s->mv[0][0][1] = h->current_mv_y * 2;
660 /* decode each block */
661 if(s->mb_intra || HAS_CBP(h->mtype)){
662 s->dsp.clear_blocks(s->block[0]);
663 for (i = 0; i < 6; i++) {
664 if (h261_decode_block(h, s->block[i], i, cbp&32) < 0){
670 for (i = 0; i < 6; i++)
671 s->block_last_index[i]= -1;
674 MPV_decode_mb(s, s->block);
680 * decodes a macroblock
681 * @return <0 if an error occured
683 static int h261_decode_block(H261Context * h, DCTELEM * block,
686 MpegEncContext * const s = &h->s;
687 int code, level, i, j, run;
688 RLTable *rl = &h261_rl_tcoeff;
689 const uint8_t *scan_table;
691 // For the variable length encoding there are two code tables, one being used for
692 // the first transmitted LEVEL in INTER, INTER+MC and INTER+MC+FIL blocks, the second
693 // for all other LEVELs except the first one in INTRA blocks which is fixed length
694 // coded with 8 bits.
695 // NOTE: the two code tables only differ in one VLC so we handle that manually.
696 scan_table = s->intra_scantable.permutated;
699 level = get_bits(&s->gb, 8);
700 // 0 (00000000b) and -128 (10000000b) are FORBIDDEN
701 if((level&0x7F) == 0){
702 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
705 // The code 1000 0000 is not used, the reconstruction level of 1024 being coded as 1111 1111.
712 // EOB Not possible for first level when cbp is available (that's why the table is different)
715 int check = show_bits(&s->gb, 2);
718 skip_bits(&s->gb, 2);
719 block[0] = ( check & 0x1 ) ? -1 : 1;
726 s->block_last_index[n] = i - 1;
730 code = get_vlc2(&s->gb, rl->vlc.table, TCOEFF_VLC_BITS, 2);
732 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
737 // The remaining combinations of (run, level) are encoded with a 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits level.
738 run = get_bits(&s->gb, 6);
739 level = get_sbits(&s->gb, 8);
743 run = rl->table_run[code];
744 level = rl->table_level[code];
745 if (get_bits1(&s->gb))
750 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n", s->mb_x, s->mb_y);
757 s->block_last_index[n] = i-1;
762 * decodes the H261 picture header.
763 * @return <0 if no startcode found
765 int h261_decode_picture_header(H261Context *h){
766 MpegEncContext * const s = &h->s;
768 uint32_t startcode= 0;
770 for(i= s->gb.size_in_bits - get_bits_count(&s->gb); i>24; i-=1){
771 startcode = ((startcode << 1) | get_bits(&s->gb, 1)) & 0x000FFFFF;
773 if(startcode == 0x10)
777 if (startcode != 0x10){
778 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
782 /* temporal reference */
783 s->picture_number = get_bits(&s->gb, 5); /* picture timestamp */
785 /* PTYPE starts here */
786 skip_bits1(&s->gb); /* split screen off */
787 skip_bits1(&s->gb); /* camera off */
788 skip_bits1(&s->gb); /* freeze picture release off */
790 format = get_bits1(&s->gb);
792 //only 2 formats possible
793 if (format == 0){//QCIF
805 s->mb_num = s->mb_width * s->mb_height;
807 skip_bits1(&s->gb); /* still image mode off */
808 skip_bits1(&s->gb); /* Reserved */
811 while (get_bits1(&s->gb) != 0){
812 skip_bits(&s->gb, 8);
815 // h261 has no I-FRAMES, but if we pass I_TYPE for the first frame, the codec crashes if it does
816 // not contain all I-blocks (e.g. when a packet is lost)
817 s->pict_type = P_TYPE;
823 static int h261_decode_gob(H261Context *h){
824 MpegEncContext * const s = &h->s;
826 ff_set_qscale(s, s->qscale);
829 while(h->current_mba <= MBA_STUFFING)
833 ret= h261_decode_mb(h);
836 h261_decode_mb_skipped(h, h->current_mba, 33);
839 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", s->mb_x + s->mb_y*s->mb_stride);
843 h261_decode_mb_skipped(h, h->current_mba-h->mba_diff, h->current_mba-1);
849 static int h261_find_frame_end(ParseContext *pc, AVCodecContext* avctx, const uint8_t *buf, int buf_size){
853 vop_found= pc->frame_start_found;
856 for(i=0; i<buf_size && !vop_found; i++){
857 state= (state<<8) | buf[i];
859 if(((state>>j)&0xFFFFF) == 0x00010){
867 for(; i<buf_size; i++){
868 state= (state<<8) | buf[i];
870 if(((state>>j)&0xFFFFF) == 0x00010){
871 pc->frame_start_found=0;
872 pc->state= state>>(2*8);
879 pc->frame_start_found= vop_found;
881 return END_NOT_FOUND;
884 static int h261_parse(AVCodecParserContext *s,
885 AVCodecContext *avctx,
886 uint8_t **poutbuf, int *poutbuf_size,
887 const uint8_t *buf, int buf_size)
889 ParseContext *pc = s->priv_data;
892 next= h261_find_frame_end(pc,avctx, buf, buf_size);
893 if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
898 *poutbuf = (uint8_t *)buf;
899 *poutbuf_size = buf_size;
904 * returns the number of bytes consumed for building the current frame
906 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
907 int pos= get_bits_count(&s->gb)>>3;
908 if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
909 if(pos+10>buf_size) pos=buf_size; // oops ;)
914 static int h261_decode_frame(AVCodecContext *avctx,
915 void *data, int *data_size,
916 uint8_t *buf, int buf_size)
918 H261Context *h= avctx->priv_data;
919 MpegEncContext *s = &h->s;
921 AVFrame *pict = data;
924 printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
925 printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
927 s->flags= avctx->flags;
928 s->flags2= avctx->flags2;
930 h->gob_start_code_skipped=0;
934 init_get_bits(&s->gb, buf, buf_size*8);
936 if(!s->context_initialized){
937 if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
941 //we need to set current_picture_ptr before reading the header, otherwise we cant store anyting im there
942 if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
943 int i= ff_find_unused_picture(s, 0);
944 s->current_picture_ptr= &s->picture[i];
947 ret = h261_decode_picture_header(h);
949 /* skip if the header was thrashed */
951 av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
955 if (s->width != avctx->coded_width || s->height != avctx->coded_height){
956 ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
957 s->parse_context.buffer=0;
959 s->parse_context= pc;
961 if (!s->context_initialized) {
962 avcodec_set_dimensions(avctx, s->width, s->height);
968 s->current_picture.pict_type= s->pict_type;
969 s->current_picture.key_frame= s->pict_type == I_TYPE;
971 /* skip everything if we are in a hurry>=5 */
972 if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
973 if( (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==B_TYPE)
974 ||(avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=I_TYPE)
975 || avctx->skip_frame >= AVDISCARD_ALL)
976 return get_consumed_bytes(s, buf_size);
978 if(MPV_frame_start(s, avctx) < 0)
981 ff_er_frame_start(s);
983 /* decode each macroblock */
987 while(h->gob_number < (s->mb_height==18 ? 12 : 5)){
988 if(ff_h261_resync(h)<0)
994 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
995 assert(s->current_picture.pict_type == s->pict_type);
996 *pict= *(AVFrame*)s->current_picture_ptr;
997 ff_print_debug_info(s, pict);
999 /* Return the Picture timestamp as the frame number */
1000 /* we substract 1 because it is added on utils.c */
1001 avctx->frame_number = s->picture_number - 1;
1003 *data_size = sizeof(AVFrame);
1005 return get_consumed_bytes(s, buf_size);
1008 static int h261_decode_end(AVCodecContext *avctx)
1010 H261Context *h= avctx->priv_data;
1011 MpegEncContext *s = &h->s;
1017 #ifdef CONFIG_ENCODERS
1018 AVCodec h261_encoder = {
1022 sizeof(H261Context),
1029 AVCodec h261_decoder = {
1033 sizeof(H261Context),
1041 AVCodecParser h261_parser = {
1043 sizeof(ParseContext),