2 * Chinese AVS video (AVS1-P2, JiZhun profile) decoder.
3 * Copyright (c) 2006 Stefan Gehrer <stefan.gehrer@gmx.de>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * Chinese AVS video (AVS1-P2, JiZhun profile) decoder
25 * @author Stefan Gehrer <stefan.gehrer@gmx.de>
33 static const uint8_t mv_scan[4] = {
38 static const uint8_t cbp_tab[64][2] = {
39 {63, 0},{15,15},{31,63},{47,31},{ 0,16},{14,32},{13,47},{11,13},
40 { 7,14},{ 5,11},{10,12},{ 8, 5},{12,10},{61, 7},{ 4,48},{55, 3},
41 { 1, 2},{ 2, 8},{59, 4},{ 3, 1},{62,61},{ 9,55},{ 6,59},{29,62},
42 {45,29},{51,27},{23,23},{39,19},{27,30},{46,28},{53, 9},{30, 6},
43 {43,60},{37,21},{60,44},{16,26},{21,51},{28,35},{19,18},{35,20},
44 {42,24},{26,53},{44,17},{32,37},{58,39},{24,45},{20,58},{17,43},
45 {18,42},{48,46},{22,36},{33,33},{25,34},{49,40},{40,52},{36,49},
46 {34,50},{50,56},{52,25},{54,22},{41,54},{56,57},{38,41},{57,38}
49 /*****************************************************************************
51 * motion vector prediction
53 ****************************************************************************/
55 static inline void store_mvs(AVSContext *h) {
56 h->col_mv[h->mbidx*4 + 0] = h->mv[MV_FWD_X0];
57 h->col_mv[h->mbidx*4 + 1] = h->mv[MV_FWD_X1];
58 h->col_mv[h->mbidx*4 + 2] = h->mv[MV_FWD_X2];
59 h->col_mv[h->mbidx*4 + 3] = h->mv[MV_FWD_X3];
62 static inline void mv_pred_direct(AVSContext *h, cavs_vector *pmv_fw,
63 cavs_vector *col_mv) {
64 cavs_vector *pmv_bw = pmv_fw + MV_BWD_OFFS;
65 int den = h->direct_den[col_mv->ref];
66 int m = col_mv->x >> 31;
68 pmv_fw->dist = h->dist[1];
69 pmv_bw->dist = h->dist[0];
72 /* scale the co-located motion vector according to its temporal span */
73 pmv_fw->x = (((den+(den*col_mv->x*pmv_fw->dist^m)-m-1)>>14)^m)-m;
74 pmv_bw->x = m-(((den+(den*col_mv->x*pmv_bw->dist^m)-m-1)>>14)^m);
76 pmv_fw->y = (((den+(den*col_mv->y*pmv_fw->dist^m)-m-1)>>14)^m)-m;
77 pmv_bw->y = m-(((den+(den*col_mv->y*pmv_bw->dist^m)-m-1)>>14)^m);
80 static inline void mv_pred_sym(AVSContext *h, cavs_vector *src, enum cavs_block size) {
81 cavs_vector *dst = src + MV_BWD_OFFS;
83 /* backward mv is the scaled and negated forward mv */
84 dst->x = -((src->x * h->sym_factor + 256) >> 9);
85 dst->y = -((src->y * h->sym_factor + 256) >> 9);
87 dst->dist = h->dist[0];
91 /*****************************************************************************
93 * residual data decoding
95 ****************************************************************************/
97 /** kth-order exponential golomb code */
98 static inline int get_ue_code(GetBitContext *gb, int order) {
100 int ret = get_ue_golomb(gb) << order;
101 return ret + get_bits(gb,order);
103 return get_ue_golomb(gb);
107 * decode coefficients from one 8x8 block, dequantize, inverse transform
108 * and add them to sample block
109 * @param r pointer to 2D VLC table
110 * @param esc_golomb_order escape codes are k-golomb with this order k
111 * @param qp quantizer
112 * @param dst location of sample block
113 * @param stride line stride in frame buffer
115 static int decode_residual_block(AVSContext *h, GetBitContext *gb,
116 const struct dec_2dvlc *r, int esc_golomb_order,
117 int qp, uint8_t *dst, int stride) {
118 int i, esc_code, level, mask;
119 unsigned int level_code, run;
120 DCTELEM level_buf[65];
122 DCTELEM *block = h->block;
125 level_code = get_ue_code(gb,r->golomb_order);
126 if(level_code >= ESCAPE_CODE) {
127 run = ((level_code - ESCAPE_CODE) >> 1) + 1;
130 esc_code = get_ue_code(gb,esc_golomb_order);
131 level = esc_code + (run > r->max_run ? 1 : r->level_add[run]);
132 while(level > r->inc_limit)
134 mask = -(level_code & 1);
135 level = (level^mask) - mask;
137 level = r->rltab[level_code][0];
138 if(!level) //end of block signal
140 run = r->rltab[level_code][1];
141 r += r->rltab[level_code][2];
143 level_buf[i] = level;
146 if(dequant(h,level_buf, run_buf, block, ff_cavs_dequant_mul[qp],
147 ff_cavs_dequant_shift[qp], i))
149 h->cdsp.cavs_idct8_add(dst,block,stride);
150 h->s.dsp.clear_block(block);
155 static inline void decode_residual_chroma(AVSContext *h) {
157 decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0,
158 ff_cavs_chroma_qp[h->qp],h->cu,h->c_stride);
160 decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0,
161 ff_cavs_chroma_qp[h->qp],h->cv,h->c_stride);
164 static inline int decode_residual_inter(AVSContext *h) {
167 /* get coded block pattern */
168 int cbp= get_ue_golomb(&h->s.gb);
170 av_log(h->s.avctx, AV_LOG_ERROR, "illegal inter cbp\n");
173 h->cbp = cbp_tab[cbp][1];
176 if(h->cbp && !h->qp_fixed)
177 h->qp = (h->qp + get_se_golomb(&h->s.gb)) & 63;
178 for(block=0;block<4;block++)
179 if(h->cbp & (1<<block))
180 decode_residual_block(h,&h->s.gb,ff_cavs_inter_dec,0,h->qp,
181 h->cy + h->luma_scan[block], h->l_stride);
182 decode_residual_chroma(h);
187 /*****************************************************************************
191 ****************************************************************************/
193 static int decode_mb_i(AVSContext *h, int cbp_code) {
194 GetBitContext *gb = &h->s.gb;
195 unsigned pred_mode_uv;
198 uint8_t *left = NULL;
203 /* get intra prediction modes from stream */
204 for(block=0;block<4;block++) {
206 int pos = ff_cavs_scan3x3[block];
208 nA = h->pred_mode_Y[pos-1];
209 nB = h->pred_mode_Y[pos-3];
210 predpred = FFMIN(nA,nB);
211 if(predpred == NOT_AVAIL) // if either is not available
212 predpred = INTRA_L_LP;
214 int rem_mode= get_bits(gb, 2);
215 predpred = rem_mode + (rem_mode >= predpred);
217 h->pred_mode_Y[pos] = predpred;
219 pred_mode_uv = get_ue_golomb(gb);
220 if(pred_mode_uv > 6) {
221 av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra chroma pred mode\n");
224 ff_cavs_modify_mb_i(h, &pred_mode_uv);
226 /* get coded block pattern */
227 if(h->pic_type == AV_PICTURE_TYPE_I)
228 cbp_code = get_ue_golomb(gb);
230 av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra cbp\n");
233 h->cbp = cbp_tab[cbp_code][0];
234 if(h->cbp && !h->qp_fixed)
235 h->qp = (h->qp + get_se_golomb(gb)) & 63; //qp_delta
237 /* luma intra prediction interleaved with residual decode/transform/add */
238 for(block=0;block<4;block++) {
239 d = h->cy + h->luma_scan[block];
240 ff_cavs_load_intra_pred_luma(h, top, &left, block);
241 h->intra_pred_l[h->pred_mode_Y[ff_cavs_scan3x3[block]]]
242 (d, top, left, h->l_stride);
243 if(h->cbp & (1<<block))
244 decode_residual_block(h,gb,ff_cavs_intra_dec,1,h->qp,d,h->l_stride);
247 /* chroma intra prediction */
248 ff_cavs_load_intra_pred_chroma(h);
249 h->intra_pred_c[pred_mode_uv](h->cu, &h->top_border_u[h->mbx*10],
250 h->left_border_u, h->c_stride);
251 h->intra_pred_c[pred_mode_uv](h->cv, &h->top_border_v[h->mbx*10],
252 h->left_border_v, h->c_stride);
254 decode_residual_chroma(h);
255 ff_cavs_filter(h,I_8X8);
260 static void decode_mb_p(AVSContext *h, enum cavs_mb mb_type) {
261 GetBitContext *gb = &h->s.gb;
267 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_PSKIP, BLK_16X16, 0);
270 ref[0] = h->ref_flag ? 0 : get_bits1(gb);
271 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16,ref[0]);
274 ref[0] = h->ref_flag ? 0 : get_bits1(gb);
275 ref[2] = h->ref_flag ? 0 : get_bits1(gb);
276 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, ref[0]);
277 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, ref[2]);
280 ref[0] = h->ref_flag ? 0 : get_bits1(gb);
281 ref[1] = h->ref_flag ? 0 : get_bits1(gb);
282 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, ref[0]);
283 ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_TOPRIGHT,BLK_8X16, ref[1]);
286 ref[0] = h->ref_flag ? 0 : get_bits1(gb);
287 ref[1] = h->ref_flag ? 0 : get_bits1(gb);
288 ref[2] = h->ref_flag ? 0 : get_bits1(gb);
289 ref[3] = h->ref_flag ? 0 : get_bits1(gb);
290 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_MEDIAN, BLK_8X8, ref[0]);
291 ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_MEDIAN, BLK_8X8, ref[1]);
292 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_X1, MV_PRED_MEDIAN, BLK_8X8, ref[2]);
293 ff_cavs_mv(h, MV_FWD_X3, MV_FWD_X0, MV_PRED_MEDIAN, BLK_8X8, ref[3]);
295 ff_cavs_inter(h, mb_type);
296 set_intra_mode_default(h);
298 if(mb_type != P_SKIP)
299 decode_residual_inter(h);
300 ff_cavs_filter(h,mb_type);
301 h->col_type_base[h->mbidx] = mb_type;
304 static void decode_mb_b(AVSContext *h, enum cavs_mb mb_type) {
306 enum cavs_sub_mb sub_type[4];
312 h->mv[MV_FWD_X0] = ff_cavs_dir_mv;
313 set_mvs(&h->mv[MV_FWD_X0], BLK_16X16);
314 h->mv[MV_BWD_X0] = ff_cavs_dir_mv;
315 set_mvs(&h->mv[MV_BWD_X0], BLK_16X16);
319 if(!h->col_type_base[h->mbidx]) {
320 /* intra MB at co-location, do in-plane prediction */
321 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_BSKIP, BLK_16X16, 1);
322 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_BSKIP, BLK_16X16, 0);
324 /* direct prediction from co-located P MB, block-wise */
325 for(block=0;block<4;block++)
326 mv_pred_direct(h,&h->mv[mv_scan[block]],
327 &h->col_mv[h->mbidx*4 + block]);
330 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);
333 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1);
334 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X16);
337 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_MEDIAN, BLK_16X16, 0);
340 for(block=0;block<4;block++)
341 sub_type[block] = get_bits(&h->s.gb,2);
342 for(block=0;block<4;block++) {
343 switch(sub_type[block]) {
345 if(!h->col_type_base[h->mbidx]) {
346 /* intra MB at co-location, do in-plane prediction */
347 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
348 MV_PRED_BSKIP, BLK_8X8, 1);
349 ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS,
350 mv_scan[block]-3+MV_BWD_OFFS,
351 MV_PRED_BSKIP, BLK_8X8, 0);
353 mv_pred_direct(h,&h->mv[mv_scan[block]],
354 &h->col_mv[h->mbidx*4 + block]);
357 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
358 MV_PRED_MEDIAN, BLK_8X8, 1);
361 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3,
362 MV_PRED_MEDIAN, BLK_8X8, 1);
363 mv_pred_sym(h, &h->mv[mv_scan[block]], BLK_8X8);
367 for(block=0;block<4;block++) {
368 if(sub_type[block] == B_SUB_BWD)
369 ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS,
370 mv_scan[block]+MV_BWD_OFFS-3,
371 MV_PRED_MEDIAN, BLK_8X8, 0);
375 assert((mb_type > B_SYM_16X16) && (mb_type < B_8X8));
376 flags = ff_cavs_partition_flags[mb_type];
377 if(mb_type & 1) { /* 16x8 macroblock types */
379 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, 1);
381 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X8);
383 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, 1);
385 mv_pred_sym(h, &h->mv[MV_FWD_X2], BLK_16X8);
387 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_TOP, BLK_16X8, 0);
389 ff_cavs_mv(h, MV_BWD_X2, MV_BWD_A1, MV_PRED_LEFT, BLK_16X8, 0);
390 } else { /* 8x16 macroblock types */
392 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, 1);
394 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_8X16);
396 ff_cavs_mv(h,MV_FWD_X1,MV_FWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,1);
398 mv_pred_sym(h, &h->mv[MV_FWD_X1], BLK_8X16);
400 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_B3, MV_PRED_LEFT, BLK_8X16, 0);
402 ff_cavs_mv(h,MV_BWD_X1,MV_BWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,0);
405 ff_cavs_inter(h, mb_type);
406 set_intra_mode_default(h);
407 if(mb_type != B_SKIP)
408 decode_residual_inter(h);
409 ff_cavs_filter(h,mb_type);
412 /*****************************************************************************
416 ****************************************************************************/
418 static inline int decode_slice_header(AVSContext *h, GetBitContext *gb) {
420 av_log(h->s.avctx, AV_LOG_ERROR, "unexpected start code 0x%02x\n", h->stc);
422 if (h->stc >= h->mb_height)
426 h->mbidx = h->mby*h->mb_width;
428 /* mark top macroblocks as unavailable */
429 h->flags &= ~(B_AVAIL|C_AVAIL);
430 if((h->mby == 0) && (!h->qp_fixed)){
431 h->qp_fixed = get_bits1(gb);
432 h->qp = get_bits(gb,6);
434 /* inter frame or second slice can have weighting params */
435 if((h->pic_type != AV_PICTURE_TYPE_I) || (!h->pic_structure && h->mby >= h->mb_width/2))
436 if(get_bits1(gb)) { //slice_weighting_flag
437 av_log(h->s.avctx, AV_LOG_ERROR,
438 "weighted prediction not yet supported\n");
443 static inline int check_for_slice(AVSContext *h) {
444 GetBitContext *gb = &h->s.gb;
449 align = (-get_bits_count(gb)) & 7;
450 /* check for stuffing byte */
451 if(!align && (show_bits(gb,8) == 0x80))
453 if((show_bits_long(gb,24+align) & 0xFFFFFF) == 0x000001) {
454 skip_bits_long(gb,24+align);
455 h->stc = get_bits(gb,8);
456 if (h->stc >= h->mb_height)
458 decode_slice_header(h,gb);
464 /*****************************************************************************
468 ****************************************************************************/
470 static int decode_pic(AVSContext *h) {
471 MpegEncContext *s = &h->s;
473 enum cavs_mb mb_type;
475 if (!s->context_initialized) {
476 s->avctx->idct_algo = FF_IDCT_CAVS;
477 if (ff_MPV_common_init(s) < 0)
479 ff_init_scantable(s->dsp.idct_permutation,&h->scantable,ff_zigzag_direct);
481 skip_bits(&s->gb,16);//bbv_dwlay
482 if(h->stc == PIC_PB_START_CODE) {
483 h->pic_type = get_bits(&s->gb,2) + AV_PICTURE_TYPE_I;
484 if(h->pic_type > AV_PICTURE_TYPE_B) {
485 av_log(s->avctx, AV_LOG_ERROR, "illegal picture type\n");
488 /* make sure we have the reference frames we need */
489 if(!h->DPB[0].f.data[0] ||
490 (!h->DPB[1].f.data[0] && h->pic_type == AV_PICTURE_TYPE_B))
493 h->pic_type = AV_PICTURE_TYPE_I;
494 if(get_bits1(&s->gb))
495 skip_bits(&s->gb,24);//time_code
496 /* old sample clips were all progressive and no low_delay,
497 bump stream revision if detected otherwise */
498 if (s->low_delay || !(show_bits(&s->gb,9) & 1))
499 h->stream_revision = 1;
500 /* similarly test top_field_first and repeat_first_field */
501 else if(show_bits(&s->gb,11) & 3)
502 h->stream_revision = 1;
503 if(h->stream_revision > 0)
504 skip_bits(&s->gb,1); //marker_bit
506 /* release last B frame */
507 if(h->picture.f.data[0])
508 s->avctx->release_buffer(s->avctx, &h->picture.f);
510 s->avctx->get_buffer(s->avctx, &h->picture.f);
512 h->picture.poc = get_bits(&s->gb,8)*2;
514 /* get temporal distances and MV scaling factors */
515 if(h->pic_type != AV_PICTURE_TYPE_B) {
516 h->dist[0] = (h->picture.poc - h->DPB[0].poc + 512) % 512;
518 h->dist[0] = (h->DPB[0].poc - h->picture.poc + 512) % 512;
520 h->dist[1] = (h->picture.poc - h->DPB[1].poc + 512) % 512;
521 h->scale_den[0] = h->dist[0] ? 512/h->dist[0] : 0;
522 h->scale_den[1] = h->dist[1] ? 512/h->dist[1] : 0;
523 if(h->pic_type == AV_PICTURE_TYPE_B) {
524 h->sym_factor = h->dist[0]*h->scale_den[1];
526 h->direct_den[0] = h->dist[0] ? 16384/h->dist[0] : 0;
527 h->direct_den[1] = h->dist[1] ? 16384/h->dist[1] : 0;
531 get_ue_golomb(&s->gb); //bbv_check_times
532 h->progressive = get_bits1(&s->gb);
533 h->pic_structure = 1;
535 h->pic_structure = get_bits1(&s->gb);
536 if(!h->pic_structure && h->stc == PIC_PB_START_CODE)
537 skip_bits1(&s->gb); //advanced_pred_mode_disable
538 skip_bits1(&s->gb); //top_field_first
539 skip_bits1(&s->gb); //repeat_first_field
540 h->qp_fixed = get_bits1(&s->gb);
541 h->qp = get_bits(&s->gb,6);
542 if(h->pic_type == AV_PICTURE_TYPE_I) {
543 if(!h->progressive && !h->pic_structure)
544 skip_bits1(&s->gb);//what is this?
545 skip_bits(&s->gb,4); //reserved bits
547 if(!(h->pic_type == AV_PICTURE_TYPE_B && h->pic_structure == 1))
548 h->ref_flag = get_bits1(&s->gb);
549 skip_bits(&s->gb,4); //reserved bits
550 h->skip_mode_flag = get_bits1(&s->gb);
552 h->loop_filter_disable = get_bits1(&s->gb);
553 if(!h->loop_filter_disable && get_bits1(&s->gb)) {
554 h->alpha_offset = get_se_golomb(&s->gb);
555 h->beta_offset = get_se_golomb(&s->gb);
557 h->alpha_offset = h->beta_offset = 0;
559 if(h->pic_type == AV_PICTURE_TYPE_I) {
563 } while(ff_cavs_next_mb(h));
564 } else if(h->pic_type == AV_PICTURE_TYPE_P) {
566 if(check_for_slice(h))
568 if(h->skip_mode_flag && (skip_count < 0))
569 skip_count = get_ue_golomb(&s->gb);
570 if(h->skip_mode_flag && skip_count--) {
571 decode_mb_p(h,P_SKIP);
573 mb_type = get_ue_golomb(&s->gb) + P_SKIP + h->skip_mode_flag;
575 decode_mb_i(h, mb_type - P_8X8 - 1);
577 decode_mb_p(h,mb_type);
579 } while(ff_cavs_next_mb(h));
580 } else { /* AV_PICTURE_TYPE_B */
582 if(check_for_slice(h))
584 if(h->skip_mode_flag && (skip_count < 0))
585 skip_count = get_ue_golomb(&s->gb);
586 if(h->skip_mode_flag && skip_count--) {
587 decode_mb_b(h,B_SKIP);
589 mb_type = get_ue_golomb(&s->gb) + B_SKIP + h->skip_mode_flag;
591 decode_mb_i(h, mb_type - B_8X8 - 1);
593 decode_mb_b(h,mb_type);
595 } while(ff_cavs_next_mb(h));
597 if(h->pic_type != AV_PICTURE_TYPE_B) {
598 if(h->DPB[1].f.data[0])
599 s->avctx->release_buffer(s->avctx, &h->DPB[1].f);
600 h->DPB[1] = h->DPB[0];
601 h->DPB[0] = h->picture;
602 memset(&h->picture,0,sizeof(Picture));
607 /*****************************************************************************
609 * headers and interface
611 ****************************************************************************/
613 static int decode_seq_header(AVSContext *h) {
614 MpegEncContext *s = &h->s;
618 h->profile = get_bits(&s->gb,8);
619 h->level = get_bits(&s->gb,8);
620 skip_bits1(&s->gb); //progressive sequence
621 width = get_bits(&s->gb,14);
622 height = get_bits(&s->gb,14);
623 if ((s->width || s->height) && (s->width != width || s->height != height)) {
624 av_log_missing_feature(s, "Width/height changing in CAVS is", 0);
629 skip_bits(&s->gb,2); //chroma format
630 skip_bits(&s->gb,3); //sample_precision
631 h->aspect_ratio = get_bits(&s->gb,4);
632 frame_rate_code = get_bits(&s->gb,4);
633 skip_bits(&s->gb,18);//bit_rate_lower
634 skip_bits1(&s->gb); //marker_bit
635 skip_bits(&s->gb,12);//bit_rate_upper
636 s->low_delay = get_bits1(&s->gb);
637 h->mb_width = (s->width + 15) >> 4;
638 h->mb_height = (s->height + 15) >> 4;
639 h->s.avctx->time_base.den = avpriv_frame_rate_tab[frame_rate_code].num;
640 h->s.avctx->time_base.num = avpriv_frame_rate_tab[frame_rate_code].den;
641 h->s.avctx->width = s->width;
642 h->s.avctx->height = s->height;
644 ff_cavs_init_top_lines(h);
648 static void cavs_flush(AVCodecContext * avctx) {
649 AVSContext *h = avctx->priv_data;
653 static int cavs_decode_frame(AVCodecContext * avctx,void *data, int *data_size,
655 const uint8_t *buf = avpkt->data;
656 int buf_size = avpkt->size;
657 AVSContext *h = avctx->priv_data;
658 MpegEncContext *s = &h->s;
660 const uint8_t *buf_end;
661 const uint8_t *buf_ptr;
662 AVFrame *picture = data;
668 if (!s->low_delay && h->DPB[0].f.data[0]) {
669 *data_size = sizeof(AVPicture);
670 *picture = h->DPB[0].f;
671 memset(&h->DPB[0], 0, sizeof(h->DPB[0]));
677 buf_end = buf + buf_size;
679 buf_ptr = avpriv_mpv_find_start_code(buf_ptr,buf_end, &stc);
680 if((stc & 0xFFFFFE00) || buf_ptr == buf_end)
681 return FFMAX(0, buf_ptr - buf - s->parse_context.last_index);
682 input_size = (buf_end - buf_ptr)*8;
684 case CAVS_START_CODE:
685 init_get_bits(&s->gb, buf_ptr, input_size);
686 decode_seq_header(h);
688 case PIC_I_START_CODE:
689 if(!h->got_keyframe) {
690 if(h->DPB[0].f.data[0])
691 avctx->release_buffer(avctx, &h->DPB[0].f);
692 if(h->DPB[1].f.data[0])
693 avctx->release_buffer(avctx, &h->DPB[1].f);
696 case PIC_PB_START_CODE:
702 init_get_bits(&s->gb, buf_ptr, input_size);
706 *data_size = sizeof(AVPicture);
707 if(h->pic_type != AV_PICTURE_TYPE_B) {
708 if(h->DPB[1].f.data[0]) {
709 *picture = h->DPB[1].f;
714 *picture = h->picture.f;
717 //mpeg_decode_extension(avctx,buf_ptr, input_size);
719 case USER_START_CODE:
720 //mpeg_decode_user_data(avctx,buf_ptr, input_size);
723 if (stc <= SLICE_MAX_START_CODE) {
724 init_get_bits(&s->gb, buf_ptr, input_size);
725 decode_slice_header(h, &s->gb);
732 AVCodec ff_cavs_decoder = {
734 .type = AVMEDIA_TYPE_VIDEO,
736 .priv_data_size = sizeof(AVSContext),
737 .init = ff_cavs_init,
738 .close = ff_cavs_end,
739 .decode = cavs_decode_frame,
740 .capabilities = CODEC_CAP_DR1 | CODEC_CAP_DELAY,
742 .long_name = NULL_IF_CONFIG_SMALL("Chinese AVS video (AVS1-P2, JiZhun profile)"),