3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31 #include "mpegvideo.h"
35 #define H261_MBA_VLC_BITS 9
36 #define H261_MTYPE_VLC_BITS 6
37 #define H261_MV_VLC_BITS 7
38 #define H261_CBP_VLC_BITS 9
39 #define TCOEFF_VLC_BITS 9
41 #define MBA_STUFFING 33
42 #define MBA_STARTCODE 34
43 #define IS_FIL(a) ((a)&MB_TYPE_H261_FIL)
48 typedef struct H261Context{
58 int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read
61 static uint8_t static_rl_table_store[2][2*MAX_RUN + MAX_LEVEL + 3];
63 void ff_h261_loop_filter(MpegEncContext *s){
64 H261Context * h= (H261Context*)s;
65 const int linesize = s->linesize;
66 const int uvlinesize= s->uvlinesize;
67 uint8_t *dest_y = s->dest[0];
68 uint8_t *dest_cb= s->dest[1];
69 uint8_t *dest_cr= s->dest[2];
71 if(!(IS_FIL (h->mtype)))
74 s->dsp.h261_loop_filter(dest_y , linesize);
75 s->dsp.h261_loop_filter(dest_y + 8, linesize);
76 s->dsp.h261_loop_filter(dest_y + 8 * linesize , linesize);
77 s->dsp.h261_loop_filter(dest_y + 8 * linesize + 8, linesize);
78 s->dsp.h261_loop_filter(dest_cb, uvlinesize);
79 s->dsp.h261_loop_filter(dest_cr, uvlinesize);
82 int ff_h261_get_picture_format(int width, int height){
84 if (width == 176 && height == 144)
87 else if (width == 352 && height == 288)
94 static void h261_encode_block(H261Context * h, DCTELEM * block,
96 static int h261_decode_block(H261Context *h, DCTELEM *block,
99 void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){
100 H261Context * h = (H261Context *) s;
101 int format, temp_ref;
103 align_put_bits(&s->pb);
105 /* Update the pointer to last GOB */
106 s->ptr_lastgob = pbBufPtr(&s->pb);
108 put_bits(&s->pb, 20, 0x10); /* PSC */
110 temp_ref= s->picture_number * (int64_t)30000 * s->avctx->time_base.num /
111 (1001 * (int64_t)s->avctx->time_base.den); //FIXME maybe this should use a timestamp
112 put_bits(&s->pb, 5, temp_ref & 0x1f); /* TemporalReference */
114 put_bits(&s->pb, 1, 0); /* split screen off */
115 put_bits(&s->pb, 1, 0); /* camera off */
116 put_bits(&s->pb, 1, 0); /* freeze picture release off */
118 format = ff_h261_get_picture_format(s->width, s->height);
120 put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */
122 put_bits(&s->pb, 1, 0); /* still image mode */
123 put_bits(&s->pb, 1, 0); /* reserved */
125 put_bits(&s->pb, 1, 0); /* no PEI */
134 * Encodes a group of blocks header.
136 static void h261_encode_gob_header(MpegEncContext * s, int mb_line){
137 H261Context * h = (H261Context *)s;
138 if(ff_h261_get_picture_format(s->width, s->height) == 0){
139 h->gob_number+=2; // QCIF
142 h->gob_number++; // CIF
144 put_bits(&s->pb, 16, 1); /* GBSC */
145 put_bits(&s->pb, 4, h->gob_number); /* GN */
146 put_bits(&s->pb, 5, s->qscale); /* GQUANT */
147 put_bits(&s->pb, 1, 0); /* no GEI */
154 void ff_h261_reorder_mb_index(MpegEncContext* s){
155 int index= s->mb_x + s->mb_y*s->mb_width;
158 h261_encode_gob_header(s,0);
160 /* for CIF the GOB's are fragmented in the middle of a scanline
161 that's why we need to adjust the x and y index of the macroblocks */
162 if(ff_h261_get_picture_format(s->width,s->height) == 1){ // CIF
163 s->mb_x = index % 11 ; index /= 11;
164 s->mb_y = index % 3 ; index /= 3;
165 s->mb_x+= 11*(index % 2); index /= 2;
168 ff_init_block_index(s);
169 ff_update_block_index(s);
173 static void h261_encode_motion(H261Context * h, int val){
174 MpegEncContext * const s = &h->s;
178 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
186 code = sign ? -val : val;
187 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
188 put_bits(&s->pb,1,sign);
192 static inline int get_cbp(MpegEncContext * s,
193 DCTELEM block[6][64])
197 for (i = 0; i < 6; i++) {
198 if (s->block_last_index[i] >= 0)
203 void ff_h261_encode_mb(MpegEncContext * s,
204 DCTELEM block[6][64],
205 int motion_x, int motion_y)
207 H261Context * h = (H261Context *)s;
208 int mvd, mv_diff_x, mv_diff_y, i, cbp;
209 cbp = 63; // avoid warning
217 cbp= get_cbp(s, block);
219 /* mvd indicates if this block is motion compensated */
220 mvd = motion_x | motion_y;
222 if((cbp | mvd | s->dquant ) == 0) {
223 /* skip macroblock */
231 /* MB is not skipped, encode MBA */
232 put_bits(&s->pb, h261_mba_bits[(h->current_mba-h->previous_mba)-1], h261_mba_code[(h->current_mba-h->previous_mba)-1]);
234 /* calculate MTYPE */
238 if(mvd || s->loop_filter)
244 assert(h->mtype > 1);
250 put_bits(&s->pb, h261_mtype_bits[h->mtype], h261_mtype_code[h->mtype]);
252 h->mtype = h261_mtype_map[h->mtype];
254 if(IS_QUANT(h->mtype)){
255 ff_set_qscale(s,s->qscale+s->dquant);
256 put_bits(&s->pb, 5, s->qscale);
259 if(IS_16X16(h->mtype)){
260 mv_diff_x = (motion_x >> 1) - h->current_mv_x;
261 mv_diff_y = (motion_y >> 1) - h->current_mv_y;
262 h->current_mv_x = (motion_x >> 1);
263 h->current_mv_y = (motion_y >> 1);
264 h261_encode_motion(h,mv_diff_x);
265 h261_encode_motion(h,mv_diff_y);
268 h->previous_mba = h->current_mba;
270 if(HAS_CBP(h->mtype)){
272 put_bits(&s->pb,h261_cbp_tab[cbp-1][1],h261_cbp_tab[cbp-1][0]);
275 /* encode each block */
276 h261_encode_block(h, block[i], i);
279 if ( ( h->current_mba == 11 ) || ( h->current_mba == 22 ) || ( h->current_mba == 33 ) || ( !IS_16X16 ( h->mtype ) )){
285 void ff_h261_encode_init(MpegEncContext *s){
290 init_rl(&h261_rl_tcoeff, static_rl_table_store);
296 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
301 * encodes a 8x8 block.
302 * @param block the 8x8 block
303 * @param n block index (0-3 are luma, 4-5 are chroma)
305 static void h261_encode_block(H261Context * h, DCTELEM * block, int n){
306 MpegEncContext * const s = &h->s;
307 int level, run, last, i, j, last_index, last_non_zero, sign, slevel, code;
310 rl = &h261_rl_tcoeff;
314 /* 255 cannot be represented, so we clamp */
319 /* 0 cannot be represented also */
320 else if (level < 1) {
325 put_bits(&s->pb, 8, 0xff);
327 put_bits(&s->pb, 8, level);
329 } else if((block[0]==1 || block[0] == -1) && (s->block_last_index[n] > -1)){
331 put_bits(&s->pb,2,block[0]>0 ? 2 : 3 );
338 last_index = s->block_last_index[n];
339 last_non_zero = i - 1;
340 for (; i <= last_index; i++) {
341 j = s->intra_scantable.permutated[i];
344 run = i - last_non_zero - 1;
345 last = (i == last_index);
352 code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/, run, level);
353 if(run==0 && level < 16)
355 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
357 put_bits(&s->pb, 6, run);
359 assert(level <= 127);
360 put_bits(&s->pb, 8, slevel & 0xff);
362 put_bits(&s->pb, 1, sign);
368 put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]);// END OF BLOCK
372 /***********************************************/
375 static VLC h261_mba_vlc;
376 static VLC h261_mtype_vlc;
377 static VLC h261_mv_vlc;
378 static VLC h261_cbp_vlc;
380 static void h261_decode_init_vlc(H261Context *h){
385 init_vlc(&h261_mba_vlc, H261_MBA_VLC_BITS, 35,
387 h261_mba_code, 1, 1, 1);
388 init_vlc(&h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
389 h261_mtype_bits, 1, 1,
390 h261_mtype_code, 1, 1, 1);
391 init_vlc(&h261_mv_vlc, H261_MV_VLC_BITS, 17,
392 &h261_mv_tab[0][1], 2, 1,
393 &h261_mv_tab[0][0], 2, 1, 1);
394 init_vlc(&h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
395 &h261_cbp_tab[0][1], 2, 1,
396 &h261_cbp_tab[0][0], 2, 1, 1);
397 init_rl(&h261_rl_tcoeff, static_rl_table_store);
398 init_vlc_rl(&h261_rl_tcoeff, 1);
402 static int h261_decode_init(AVCodecContext *avctx){
403 H261Context *h= avctx->priv_data;
404 MpegEncContext * const s = &h->s;
407 MPV_decode_defaults(s);
410 s->width = s->avctx->coded_width;
411 s->height = s->avctx->coded_height;
412 s->codec_id = s->avctx->codec->id;
414 s->out_format = FMT_H261;
416 avctx->pix_fmt= PIX_FMT_YUV420P;
418 s->codec_id= avctx->codec->id;
420 h261_decode_init_vlc(h);
422 h->gob_start_code_skipped = 0;
428 * decodes the group of blocks header or slice header.
429 * @return <0 if an error occured
431 static int h261_decode_gob_header(H261Context *h){
433 MpegEncContext * const s = &h->s;
435 if ( !h->gob_start_code_skipped ){
436 /* Check for GOB Start Code */
437 val = show_bits(&s->gb, 15);
442 skip_bits(&s->gb, 16);
445 h->gob_start_code_skipped = 0;
447 h->gob_number = get_bits(&s->gb, 4); /* GN */
448 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
450 /* Check if gob_number is valid */
451 if (s->mb_height==18){ //cif
452 if ((h->gob_number<=0) || (h->gob_number>12))
456 if ((h->gob_number!=1) && (h->gob_number!=3) && (h->gob_number!=5))
461 while (get_bits1(&s->gb) != 0) {
462 skip_bits(&s->gb, 8);
468 // For the first transmitted macroblock in a GOB, MBA is the absolute address. For
469 // subsequent macroblocks, MBA is the difference between the absolute addresses of
470 // the macroblock and the last transmitted macroblock.
478 * decodes the group of blocks / video packet header.
479 * @return <0 if no resync found
481 static int ff_h261_resync(H261Context *h){
482 MpegEncContext * const s = &h->s;
485 if ( h->gob_start_code_skipped ){
486 ret= h261_decode_gob_header(h);
491 if(show_bits(&s->gb, 15)==0){
492 ret= h261_decode_gob_header(h);
496 //ok, its not where its supposed to be ...
497 s->gb= s->last_resync_gb;
498 align_get_bits(&s->gb);
499 left= s->gb.size_in_bits - get_bits_count(&s->gb);
501 for(;left>15+1+4+5; left-=8){
502 if(show_bits(&s->gb, 15)==0){
503 GetBitContext bak= s->gb;
505 ret= h261_decode_gob_header(h);
511 skip_bits(&s->gb, 8);
519 * decodes skipped macroblocks
522 static int h261_decode_mb_skipped(H261Context *h, int mba1, int mba2 )
524 MpegEncContext * const s = &h->s;
529 for(i=mba1; i<mba2; i++){
532 s->mb_x= ((h->gob_number-1) % 2) * 11 + i % 11;
533 s->mb_y= ((h->gob_number-1) / 2) * 3 + i / 11;
534 xy = s->mb_x + s->mb_y * s->mb_stride;
535 ff_init_block_index(s);
536 ff_update_block_index(s);
539 s->block_last_index[j] = -1;
541 s->mv_dir = MV_DIR_FORWARD;
542 s->mv_type = MV_TYPE_16X16;
543 s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
547 h->mtype &= ~MB_TYPE_H261_FIL;
549 MPV_decode_mb(s, s->block);
555 static int decode_mv_component(GetBitContext *gb, int v){
556 int mv_diff = get_vlc2(gb, h261_mv_vlc.table, H261_MV_VLC_BITS, 2);
558 /* check if mv_diff is valid */
562 mv_diff = mvmap[mv_diff];
564 if(mv_diff && !get_bits1(gb))
569 else if(v >= 16) v-= 32;
574 static int h261_decode_mb(H261Context *h){
575 MpegEncContext * const s = &h->s;
581 h->mba_diff = get_vlc2(&s->gb, h261_mba_vlc.table, H261_MBA_VLC_BITS, 2);
583 /* Check for slice end */
584 /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */
585 if (h->mba_diff == MBA_STARTCODE){ // start code
586 h->gob_start_code_skipped = 1;
590 while( h->mba_diff == MBA_STUFFING ); // stuffing
592 if ( h->mba_diff < 0 ){
593 if ( get_bits_count(&s->gb) + 7 >= s->gb.size_in_bits )
596 av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y);
601 h->current_mba += h->mba_diff;
603 if ( h->current_mba > MBA_STUFFING )
606 s->mb_x= ((h->gob_number-1) % 2) * 11 + ((h->current_mba-1) % 11);
607 s->mb_y= ((h->gob_number-1) / 2) * 3 + ((h->current_mba-1) / 11);
608 xy = s->mb_x + s->mb_y * s->mb_stride;
609 ff_init_block_index(s);
610 ff_update_block_index(s);
613 h->mtype = get_vlc2(&s->gb, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2);
614 h->mtype = h261_mtype_map[h->mtype];
617 if ( IS_QUANT ( h->mtype ) ){
618 ff_set_qscale(s, get_bits(&s->gb, 5));
621 s->mb_intra = IS_INTRA4x4(h->mtype);
624 if ( IS_16X16 ( h->mtype ) ){
625 // Motion vector data is included for all MC macroblocks. MVD is obtained from the macroblock vector by subtracting the
626 // vector of the preceding macroblock. For this calculation the vector of the preceding macroblock is regarded as zero in the
627 // following three situations:
628 // 1) evaluating MVD for macroblocks 1, 12 and 23;
629 // 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1;
630 // 3) MTYPE of the previous macroblock was not MC.
631 if ( ( h->current_mba == 1 ) || ( h->current_mba == 12 ) || ( h->current_mba == 23 ) ||
638 h->current_mv_x= decode_mv_component(&s->gb, h->current_mv_x);
639 h->current_mv_y= decode_mv_component(&s->gb, h->current_mv_y);
646 if ( HAS_CBP( h->mtype ) ){
647 cbp = get_vlc2(&s->gb, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1;
651 s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
656 s->mv_dir = MV_DIR_FORWARD;
657 s->mv_type = MV_TYPE_16X16;
658 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
659 s->mv[0][0][0] = h->current_mv_x * 2;//gets divided by 2 in motion compensation
660 s->mv[0][0][1] = h->current_mv_y * 2;
663 /* decode each block */
664 if(s->mb_intra || HAS_CBP(h->mtype)){
665 s->dsp.clear_blocks(s->block[0]);
666 for (i = 0; i < 6; i++) {
667 if (h261_decode_block(h, s->block[i], i, cbp&32) < 0){
673 for (i = 0; i < 6; i++)
674 s->block_last_index[i]= -1;
677 MPV_decode_mb(s, s->block);
683 * decodes a macroblock
684 * @return <0 if an error occured
686 static int h261_decode_block(H261Context * h, DCTELEM * block,
689 MpegEncContext * const s = &h->s;
690 int code, level, i, j, run;
691 RLTable *rl = &h261_rl_tcoeff;
692 const uint8_t *scan_table;
694 // For the variable length encoding there are two code tables, one being used for
695 // the first transmitted LEVEL in INTER, INTER+MC and INTER+MC+FIL blocks, the second
696 // for all other LEVELs except the first one in INTRA blocks which is fixed length
697 // coded with 8 bits.
698 // NOTE: the two code tables only differ in one VLC so we handle that manually.
699 scan_table = s->intra_scantable.permutated;
702 level = get_bits(&s->gb, 8);
703 // 0 (00000000b) and -128 (10000000b) are FORBIDDEN
704 if((level&0x7F) == 0){
705 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
708 // The code 1000 0000 is not used, the reconstruction level of 1024 being coded as 1111 1111.
715 // EOB Not possible for first level when cbp is available (that's why the table is different)
718 int check = show_bits(&s->gb, 2);
721 skip_bits(&s->gb, 2);
722 block[0] = ( check & 0x1 ) ? -1 : 1;
729 s->block_last_index[n] = i - 1;
733 code = get_vlc2(&s->gb, rl->vlc.table, TCOEFF_VLC_BITS, 2);
735 av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
740 // 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.
741 run = get_bits(&s->gb, 6);
742 level = get_sbits(&s->gb, 8);
746 run = rl->table_run[code];
747 level = rl->table_level[code];
748 if (get_bits1(&s->gb))
753 av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n", s->mb_x, s->mb_y);
760 s->block_last_index[n] = i-1;
765 * decodes the H261 picture header.
766 * @return <0 if no startcode found
768 static int h261_decode_picture_header(H261Context *h){
769 MpegEncContext * const s = &h->s;
771 uint32_t startcode= 0;
773 for(i= s->gb.size_in_bits - get_bits_count(&s->gb); i>24; i-=1){
774 startcode = ((startcode << 1) | get_bits(&s->gb, 1)) & 0x000FFFFF;
776 if(startcode == 0x10)
780 if (startcode != 0x10){
781 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
785 /* temporal reference */
786 i= get_bits(&s->gb, 5); /* picture timestamp */
787 if(i < (s->picture_number&31))
789 s->picture_number = (s->picture_number&~31) + i;
791 s->avctx->time_base= (AVRational){1001, 30000};
792 s->current_picture.pts= s->picture_number;
795 /* PTYPE starts here */
796 skip_bits1(&s->gb); /* split screen off */
797 skip_bits1(&s->gb); /* camera off */
798 skip_bits1(&s->gb); /* freeze picture release off */
800 format = get_bits1(&s->gb);
802 //only 2 formats possible
803 if (format == 0){//QCIF
815 s->mb_num = s->mb_width * s->mb_height;
817 skip_bits1(&s->gb); /* still image mode off */
818 skip_bits1(&s->gb); /* Reserved */
821 while (get_bits1(&s->gb) != 0){
822 skip_bits(&s->gb, 8);
825 // h261 has no I-FRAMES, but if we pass I_TYPE for the first frame, the codec crashes if it does
826 // not contain all I-blocks (e.g. when a packet is lost)
827 s->pict_type = P_TYPE;
833 static int h261_decode_gob(H261Context *h){
834 MpegEncContext * const s = &h->s;
836 ff_set_qscale(s, s->qscale);
839 while(h->current_mba <= MBA_STUFFING)
843 ret= h261_decode_mb(h);
846 h261_decode_mb_skipped(h, h->current_mba, 33);
849 av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", s->mb_x + s->mb_y*s->mb_stride);
853 h261_decode_mb_skipped(h, h->current_mba-h->mba_diff, h->current_mba-1);
859 #ifdef CONFIG_H261_PARSER
860 static int h261_find_frame_end(ParseContext *pc, AVCodecContext* avctx, const uint8_t *buf, int buf_size){
864 vop_found= pc->frame_start_found;
867 for(i=0; i<buf_size && !vop_found; i++){
868 state= (state<<8) | buf[i];
870 if(((state>>j)&0xFFFFF) == 0x00010){
877 for(; i<buf_size; i++){
878 state= (state<<8) | buf[i];
880 if(((state>>j)&0xFFFFF) == 0x00010){
881 pc->frame_start_found=0;
882 pc->state= state>>(2*8);
889 pc->frame_start_found= vop_found;
891 return END_NOT_FOUND;
894 static int h261_parse(AVCodecParserContext *s,
895 AVCodecContext *avctx,
896 uint8_t **poutbuf, int *poutbuf_size,
897 const uint8_t *buf, int buf_size)
899 ParseContext *pc = s->priv_data;
902 next= h261_find_frame_end(pc,avctx, buf, buf_size);
903 if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
908 *poutbuf = (uint8_t *)buf;
909 *poutbuf_size = buf_size;
915 * returns the number of bytes consumed for building the current frame
917 static int get_consumed_bytes(MpegEncContext *s, int buf_size){
918 int pos= get_bits_count(&s->gb)>>3;
919 if(pos==0) pos=1; //avoid infinite loops (i doubt thats needed but ...)
920 if(pos+10>buf_size) pos=buf_size; // oops ;)
925 static int h261_decode_frame(AVCodecContext *avctx,
926 void *data, int *data_size,
927 uint8_t *buf, int buf_size)
929 H261Context *h= avctx->priv_data;
930 MpegEncContext *s = &h->s;
932 AVFrame *pict = data;
935 av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
936 av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
938 s->flags= avctx->flags;
939 s->flags2= avctx->flags2;
941 h->gob_start_code_skipped=0;
945 init_get_bits(&s->gb, buf, buf_size*8);
947 if(!s->context_initialized){
948 if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix
952 //we need to set current_picture_ptr before reading the header, otherwise we cant store anyting im there
953 if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){
954 int i= ff_find_unused_picture(s, 0);
955 s->current_picture_ptr= &s->picture[i];
958 ret = h261_decode_picture_header(h);
960 /* skip if the header was thrashed */
962 av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
966 if (s->width != avctx->coded_width || s->height != avctx->coded_height){
967 ParseContext pc= s->parse_context; //FIXME move these demuxng hack to avformat
968 s->parse_context.buffer=0;
970 s->parse_context= pc;
972 if (!s->context_initialized) {
973 avcodec_set_dimensions(avctx, s->width, s->height);
979 s->current_picture.pict_type= s->pict_type;
980 s->current_picture.key_frame= s->pict_type == I_TYPE;
982 /* skip everything if we are in a hurry>=5 */
983 if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size);
984 if( (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==B_TYPE)
985 ||(avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=I_TYPE)
986 || avctx->skip_frame >= AVDISCARD_ALL)
987 return get_consumed_bytes(s, buf_size);
989 if(MPV_frame_start(s, avctx) < 0)
992 ff_er_frame_start(s);
994 /* decode each macroblock */
998 while(h->gob_number < (s->mb_height==18 ? 12 : 5)){
999 if(ff_h261_resync(h)<0)
1005 assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type);
1006 assert(s->current_picture.pict_type == s->pict_type);
1007 *pict= *(AVFrame*)s->current_picture_ptr;
1008 ff_print_debug_info(s, pict);
1010 *data_size = sizeof(AVFrame);
1012 return get_consumed_bytes(s, buf_size);
1015 static int h261_decode_end(AVCodecContext *avctx)
1017 H261Context *h= avctx->priv_data;
1018 MpegEncContext *s = &h->s;
1024 #ifdef CONFIG_ENCODERS
1025 AVCodec h261_encoder = {
1029 sizeof(H261Context),
1033 .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUV420P, -1},
1037 AVCodec h261_decoder = {
1041 sizeof(H261Context),
1049 #ifdef CONFIG_H261_PARSER
1050 AVCodecParser h261_parser = {
1052 sizeof(ParseContext),