Libav
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00001 /* 00002 * Chinese AVS video (AVS1-P2, JiZhun profile) decoder. 00003 * Copyright (c) 2006 Stefan Gehrer <stefan.gehrer@gmx.de> 00004 * 00005 * This file is part of FFmpeg. 00006 * 00007 * FFmpeg is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * FFmpeg is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with FFmpeg; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00028 #include "avcodec.h" 00029 #include "get_bits.h" 00030 #include "golomb.h" 00031 #include "cavs.h" 00032 00033 static const uint8_t mv_scan[4] = { 00034 MV_FWD_X0,MV_FWD_X1, 00035 MV_FWD_X2,MV_FWD_X3 00036 }; 00037 00038 static const uint8_t cbp_tab[64][2] = { 00039 {63, 0},{15,15},{31,63},{47,31},{ 0,16},{14,32},{13,47},{11,13}, 00040 { 7,14},{ 5,11},{10,12},{ 8, 5},{12,10},{61, 7},{ 4,48},{55, 3}, 00041 { 1, 2},{ 2, 8},{59, 4},{ 3, 1},{62,61},{ 9,55},{ 6,59},{29,62}, 00042 {45,29},{51,27},{23,23},{39,19},{27,30},{46,28},{53, 9},{30, 6}, 00043 {43,60},{37,21},{60,44},{16,26},{21,51},{28,35},{19,18},{35,20}, 00044 {42,24},{26,53},{44,17},{32,37},{58,39},{24,45},{20,58},{17,43}, 00045 {18,42},{48,46},{22,36},{33,33},{25,34},{49,40},{40,52},{36,49}, 00046 {34,50},{50,56},{52,25},{54,22},{41,54},{56,57},{38,41},{57,38} 00047 }; 00048 00049 /***************************************************************************** 00050 * 00051 * motion vector prediction 00052 * 00053 ****************************************************************************/ 00054 00055 static inline void store_mvs(AVSContext *h) { 00056 h->col_mv[h->mbidx*4 + 0] = h->mv[MV_FWD_X0]; 00057 h->col_mv[h->mbidx*4 + 1] = h->mv[MV_FWD_X1]; 00058 h->col_mv[h->mbidx*4 + 2] = h->mv[MV_FWD_X2]; 00059 h->col_mv[h->mbidx*4 + 3] = h->mv[MV_FWD_X3]; 00060 } 00061 00062 static inline void mv_pred_direct(AVSContext *h, cavs_vector *pmv_fw, 00063 cavs_vector *col_mv) { 00064 cavs_vector *pmv_bw = pmv_fw + MV_BWD_OFFS; 00065 int den = h->direct_den[col_mv->ref]; 00066 int m = col_mv->x >> 31; 00067 00068 pmv_fw->dist = h->dist[1]; 00069 pmv_bw->dist = h->dist[0]; 00070 pmv_fw->ref = 1; 00071 pmv_bw->ref = 0; 00072 /* scale the co-located motion vector according to its temporal span */ 00073 pmv_fw->x = (((den+(den*col_mv->x*pmv_fw->dist^m)-m-1)>>14)^m)-m; 00074 pmv_bw->x = m-(((den+(den*col_mv->x*pmv_bw->dist^m)-m-1)>>14)^m); 00075 m = col_mv->y >> 31; 00076 pmv_fw->y = (((den+(den*col_mv->y*pmv_fw->dist^m)-m-1)>>14)^m)-m; 00077 pmv_bw->y = m-(((den+(den*col_mv->y*pmv_bw->dist^m)-m-1)>>14)^m); 00078 } 00079 00080 static inline void mv_pred_sym(AVSContext *h, cavs_vector *src, enum cavs_block size) { 00081 cavs_vector *dst = src + MV_BWD_OFFS; 00082 00083 /* backward mv is the scaled and negated forward mv */ 00084 dst->x = -((src->x * h->sym_factor + 256) >> 9); 00085 dst->y = -((src->y * h->sym_factor + 256) >> 9); 00086 dst->ref = 0; 00087 dst->dist = h->dist[0]; 00088 set_mvs(dst, size); 00089 } 00090 00091 /***************************************************************************** 00092 * 00093 * residual data decoding 00094 * 00095 ****************************************************************************/ 00096 00098 static inline int get_ue_code(GetBitContext *gb, int order) { 00099 if(order) { 00100 int ret = get_ue_golomb(gb) << order; 00101 return ret + get_bits(gb,order); 00102 } 00103 return get_ue_golomb(gb); 00104 } 00105 00115 static int decode_residual_block(AVSContext *h, GetBitContext *gb, 00116 const struct dec_2dvlc *r, int esc_golomb_order, 00117 int qp, uint8_t *dst, int stride) { 00118 int i, level_code, esc_code, level, run, mask; 00119 DCTELEM level_buf[65]; 00120 uint8_t run_buf[65]; 00121 DCTELEM *block = h->block; 00122 00123 for(i=0;i<65;i++) { 00124 level_code = get_ue_code(gb,r->golomb_order); 00125 if(level_code >= ESCAPE_CODE) { 00126 run = ((level_code - ESCAPE_CODE) >> 1) + 1; 00127 esc_code = get_ue_code(gb,esc_golomb_order); 00128 level = esc_code + (run > r->max_run ? 1 : r->level_add[run]); 00129 while(level > r->inc_limit) 00130 r++; 00131 mask = -(level_code & 1); 00132 level = (level^mask) - mask; 00133 } else { 00134 level = r->rltab[level_code][0]; 00135 if(!level) //end of block signal 00136 break; 00137 run = r->rltab[level_code][1]; 00138 r += r->rltab[level_code][2]; 00139 } 00140 level_buf[i] = level; 00141 run_buf[i] = run; 00142 } 00143 if(dequant(h,level_buf, run_buf, block, ff_cavs_dequant_mul[qp], 00144 ff_cavs_dequant_shift[qp], i)) 00145 return -1; 00146 h->s.dsp.cavs_idct8_add(dst,block,stride); 00147 h->s.dsp.clear_block(block); 00148 return 0; 00149 } 00150 00151 00152 static inline void decode_residual_chroma(AVSContext *h) { 00153 if(h->cbp & (1<<4)) 00154 decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0, 00155 ff_cavs_chroma_qp[h->qp],h->cu,h->c_stride); 00156 if(h->cbp & (1<<5)) 00157 decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0, 00158 ff_cavs_chroma_qp[h->qp],h->cv,h->c_stride); 00159 } 00160 00161 static inline int decode_residual_inter(AVSContext *h) { 00162 int block; 00163 00164 /* get coded block pattern */ 00165 int cbp= get_ue_golomb(&h->s.gb); 00166 if(cbp > 63){ 00167 av_log(h->s.avctx, AV_LOG_ERROR, "illegal inter cbp\n"); 00168 return -1; 00169 } 00170 h->cbp = cbp_tab[cbp][1]; 00171 00172 /* get quantizer */ 00173 if(h->cbp && !h->qp_fixed) 00174 h->qp = (h->qp + get_se_golomb(&h->s.gb)) & 63; 00175 for(block=0;block<4;block++) 00176 if(h->cbp & (1<<block)) 00177 decode_residual_block(h,&h->s.gb,ff_cavs_inter_dec,0,h->qp, 00178 h->cy + h->luma_scan[block], h->l_stride); 00179 decode_residual_chroma(h); 00180 00181 return 0; 00182 } 00183 00184 /***************************************************************************** 00185 * 00186 * macroblock level 00187 * 00188 ****************************************************************************/ 00189 00190 static int decode_mb_i(AVSContext *h, int cbp_code) { 00191 GetBitContext *gb = &h->s.gb; 00192 int block, pred_mode_uv; 00193 uint8_t top[18]; 00194 uint8_t *left = NULL; 00195 uint8_t *d; 00196 00197 ff_cavs_init_mb(h); 00198 00199 /* get intra prediction modes from stream */ 00200 for(block=0;block<4;block++) { 00201 int nA,nB,predpred; 00202 int pos = ff_cavs_scan3x3[block]; 00203 00204 nA = h->pred_mode_Y[pos-1]; 00205 nB = h->pred_mode_Y[pos-3]; 00206 predpred = FFMIN(nA,nB); 00207 if(predpred == NOT_AVAIL) // if either is not available 00208 predpred = INTRA_L_LP; 00209 if(!get_bits1(gb)){ 00210 int rem_mode= get_bits(gb, 2); 00211 predpred = rem_mode + (rem_mode >= predpred); 00212 } 00213 h->pred_mode_Y[pos] = predpred; 00214 } 00215 pred_mode_uv = get_ue_golomb(gb); 00216 if(pred_mode_uv > 6) { 00217 av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra chroma pred mode\n"); 00218 return -1; 00219 } 00220 ff_cavs_modify_mb_i(h, &pred_mode_uv); 00221 00222 /* get coded block pattern */ 00223 if(h->pic_type == FF_I_TYPE) 00224 cbp_code = get_ue_golomb(gb); 00225 if(cbp_code > 63){ 00226 av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra cbp\n"); 00227 return -1; 00228 } 00229 h->cbp = cbp_tab[cbp_code][0]; 00230 if(h->cbp && !h->qp_fixed) 00231 h->qp = (h->qp + get_se_golomb(gb)) & 63; //qp_delta 00232 00233 /* luma intra prediction interleaved with residual decode/transform/add */ 00234 for(block=0;block<4;block++) { 00235 d = h->cy + h->luma_scan[block]; 00236 ff_cavs_load_intra_pred_luma(h, top, &left, block); 00237 h->intra_pred_l[h->pred_mode_Y[ff_cavs_scan3x3[block]]] 00238 (d, top, left, h->l_stride); 00239 if(h->cbp & (1<<block)) 00240 decode_residual_block(h,gb,ff_cavs_intra_dec,1,h->qp,d,h->l_stride); 00241 } 00242 00243 /* chroma intra prediction */ 00244 ff_cavs_load_intra_pred_chroma(h); 00245 h->intra_pred_c[pred_mode_uv](h->cu, &h->top_border_u[h->mbx*10], 00246 h->left_border_u, h->c_stride); 00247 h->intra_pred_c[pred_mode_uv](h->cv, &h->top_border_v[h->mbx*10], 00248 h->left_border_v, h->c_stride); 00249 00250 decode_residual_chroma(h); 00251 ff_cavs_filter(h,I_8X8); 00252 set_mv_intra(h); 00253 return 0; 00254 } 00255 00256 static void decode_mb_p(AVSContext *h, enum cavs_mb mb_type) { 00257 GetBitContext *gb = &h->s.gb; 00258 int ref[4]; 00259 00260 ff_cavs_init_mb(h); 00261 switch(mb_type) { 00262 case P_SKIP: 00263 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_PSKIP, BLK_16X16, 0); 00264 break; 00265 case P_16X16: 00266 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00267 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16,ref[0]); 00268 break; 00269 case P_16X8: 00270 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00271 ref[2] = h->ref_flag ? 0 : get_bits1(gb); 00272 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, ref[0]); 00273 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, ref[2]); 00274 break; 00275 case P_8X16: 00276 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00277 ref[1] = h->ref_flag ? 0 : get_bits1(gb); 00278 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, ref[0]); 00279 ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_TOPRIGHT,BLK_8X16, ref[1]); 00280 break; 00281 case P_8X8: 00282 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00283 ref[1] = h->ref_flag ? 0 : get_bits1(gb); 00284 ref[2] = h->ref_flag ? 0 : get_bits1(gb); 00285 ref[3] = h->ref_flag ? 0 : get_bits1(gb); 00286 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_MEDIAN, BLK_8X8, ref[0]); 00287 ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_MEDIAN, BLK_8X8, ref[1]); 00288 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_X1, MV_PRED_MEDIAN, BLK_8X8, ref[2]); 00289 ff_cavs_mv(h, MV_FWD_X3, MV_FWD_X0, MV_PRED_MEDIAN, BLK_8X8, ref[3]); 00290 } 00291 ff_cavs_inter(h, mb_type); 00292 set_intra_mode_default(h); 00293 store_mvs(h); 00294 if(mb_type != P_SKIP) 00295 decode_residual_inter(h); 00296 ff_cavs_filter(h,mb_type); 00297 h->col_type_base[h->mbidx] = mb_type; 00298 } 00299 00300 static void decode_mb_b(AVSContext *h, enum cavs_mb mb_type) { 00301 int block; 00302 enum cavs_sub_mb sub_type[4]; 00303 int flags; 00304 00305 ff_cavs_init_mb(h); 00306 00307 /* reset all MVs */ 00308 h->mv[MV_FWD_X0] = ff_cavs_dir_mv; 00309 set_mvs(&h->mv[MV_FWD_X0], BLK_16X16); 00310 h->mv[MV_BWD_X0] = ff_cavs_dir_mv; 00311 set_mvs(&h->mv[MV_BWD_X0], BLK_16X16); 00312 switch(mb_type) { 00313 case B_SKIP: 00314 case B_DIRECT: 00315 if(!h->col_type_base[h->mbidx]) { 00316 /* intra MB at co-location, do in-plane prediction */ 00317 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_BSKIP, BLK_16X16, 1); 00318 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_BSKIP, BLK_16X16, 0); 00319 } else 00320 /* direct prediction from co-located P MB, block-wise */ 00321 for(block=0;block<4;block++) 00322 mv_pred_direct(h,&h->mv[mv_scan[block]], 00323 &h->col_mv[h->mbidx*4 + block]); 00324 break; 00325 case B_FWD_16X16: 00326 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1); 00327 break; 00328 case B_SYM_16X16: 00329 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1); 00330 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X16); 00331 break; 00332 case B_BWD_16X16: 00333 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_MEDIAN, BLK_16X16, 0); 00334 break; 00335 case B_8X8: 00336 for(block=0;block<4;block++) 00337 sub_type[block] = get_bits(&h->s.gb,2); 00338 for(block=0;block<4;block++) { 00339 switch(sub_type[block]) { 00340 case B_SUB_DIRECT: 00341 if(!h->col_type_base[h->mbidx]) { 00342 /* intra MB at co-location, do in-plane prediction */ 00343 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3, 00344 MV_PRED_BSKIP, BLK_8X8, 1); 00345 ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS, 00346 mv_scan[block]-3+MV_BWD_OFFS, 00347 MV_PRED_BSKIP, BLK_8X8, 0); 00348 } else 00349 mv_pred_direct(h,&h->mv[mv_scan[block]], 00350 &h->col_mv[h->mbidx*4 + block]); 00351 break; 00352 case B_SUB_FWD: 00353 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3, 00354 MV_PRED_MEDIAN, BLK_8X8, 1); 00355 break; 00356 case B_SUB_SYM: 00357 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3, 00358 MV_PRED_MEDIAN, BLK_8X8, 1); 00359 mv_pred_sym(h, &h->mv[mv_scan[block]], BLK_8X8); 00360 break; 00361 } 00362 } 00363 for(block=0;block<4;block++) { 00364 if(sub_type[block] == B_SUB_BWD) 00365 ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS, 00366 mv_scan[block]+MV_BWD_OFFS-3, 00367 MV_PRED_MEDIAN, BLK_8X8, 0); 00368 } 00369 break; 00370 default: 00371 assert((mb_type > B_SYM_16X16) && (mb_type < B_8X8)); 00372 flags = ff_cavs_partition_flags[mb_type]; 00373 if(mb_type & 1) { /* 16x8 macroblock types */ 00374 if(flags & FWD0) 00375 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, 1); 00376 if(flags & SYM0) 00377 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X8); 00378 if(flags & FWD1) 00379 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, 1); 00380 if(flags & SYM1) 00381 mv_pred_sym(h, &h->mv[MV_FWD_X2], BLK_16X8); 00382 if(flags & BWD0) 00383 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_TOP, BLK_16X8, 0); 00384 if(flags & BWD1) 00385 ff_cavs_mv(h, MV_BWD_X2, MV_BWD_A1, MV_PRED_LEFT, BLK_16X8, 0); 00386 } else { /* 8x16 macroblock types */ 00387 if(flags & FWD0) 00388 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, 1); 00389 if(flags & SYM0) 00390 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_8X16); 00391 if(flags & FWD1) 00392 ff_cavs_mv(h,MV_FWD_X1,MV_FWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,1); 00393 if(flags & SYM1) 00394 mv_pred_sym(h, &h->mv[MV_FWD_X1], BLK_8X16); 00395 if(flags & BWD0) 00396 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_B3, MV_PRED_LEFT, BLK_8X16, 0); 00397 if(flags & BWD1) 00398 ff_cavs_mv(h,MV_BWD_X1,MV_BWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,0); 00399 } 00400 } 00401 ff_cavs_inter(h, mb_type); 00402 set_intra_mode_default(h); 00403 if(mb_type != B_SKIP) 00404 decode_residual_inter(h); 00405 ff_cavs_filter(h,mb_type); 00406 } 00407 00408 /***************************************************************************** 00409 * 00410 * slice level 00411 * 00412 ****************************************************************************/ 00413 00414 static inline int decode_slice_header(AVSContext *h, GetBitContext *gb) { 00415 if(h->stc > 0xAF) 00416 av_log(h->s.avctx, AV_LOG_ERROR, "unexpected start code 0x%02x\n", h->stc); 00417 h->mby = h->stc; 00418 h->mbidx = h->mby*h->mb_width; 00419 00420 /* mark top macroblocks as unavailable */ 00421 h->flags &= ~(B_AVAIL|C_AVAIL); 00422 if((h->mby == 0) && (!h->qp_fixed)){ 00423 h->qp_fixed = get_bits1(gb); 00424 h->qp = get_bits(gb,6); 00425 } 00426 /* inter frame or second slice can have weighting params */ 00427 if((h->pic_type != FF_I_TYPE) || (!h->pic_structure && h->mby >= h->mb_width/2)) 00428 if(get_bits1(gb)) { //slice_weighting_flag 00429 av_log(h->s.avctx, AV_LOG_ERROR, 00430 "weighted prediction not yet supported\n"); 00431 } 00432 return 0; 00433 } 00434 00435 static inline int check_for_slice(AVSContext *h) { 00436 GetBitContext *gb = &h->s.gb; 00437 int align; 00438 00439 if(h->mbx) 00440 return 0; 00441 align = (-get_bits_count(gb)) & 7; 00442 /* check for stuffing byte */ 00443 if(!align && (show_bits(gb,8) == 0x80)) 00444 align = 8; 00445 if((show_bits_long(gb,24+align) & 0xFFFFFF) == 0x000001) { 00446 skip_bits_long(gb,24+align); 00447 h->stc = get_bits(gb,8); 00448 decode_slice_header(h,gb); 00449 return 1; 00450 } 00451 return 0; 00452 } 00453 00454 /***************************************************************************** 00455 * 00456 * frame level 00457 * 00458 ****************************************************************************/ 00459 00460 static int decode_pic(AVSContext *h) { 00461 MpegEncContext *s = &h->s; 00462 int skip_count = -1; 00463 enum cavs_mb mb_type; 00464 00465 if (!s->context_initialized) { 00466 s->avctx->idct_algo = FF_IDCT_CAVS; 00467 if (MPV_common_init(s) < 0) 00468 return -1; 00469 ff_init_scantable(s->dsp.idct_permutation,&h->scantable,ff_zigzag_direct); 00470 } 00471 skip_bits(&s->gb,16);//bbv_dwlay 00472 if(h->stc == PIC_PB_START_CODE) { 00473 h->pic_type = get_bits(&s->gb,2) + FF_I_TYPE; 00474 if(h->pic_type > FF_B_TYPE) { 00475 av_log(s->avctx, AV_LOG_ERROR, "illegal picture type\n"); 00476 return -1; 00477 } 00478 /* make sure we have the reference frames we need */ 00479 if(!h->DPB[0].data[0] || 00480 (!h->DPB[1].data[0] && h->pic_type == FF_B_TYPE)) 00481 return -1; 00482 } else { 00483 h->pic_type = FF_I_TYPE; 00484 if(get_bits1(&s->gb)) 00485 skip_bits(&s->gb,24);//time_code 00486 /* old sample clips were all progressive and no low_delay, 00487 bump stream revision if detected otherwise */ 00488 if((s->low_delay) || !(show_bits(&s->gb,9) & 1)) 00489 h->stream_revision = 1; 00490 /* similarly test top_field_first and repeat_first_field */ 00491 else if(show_bits(&s->gb,11) & 3) 00492 h->stream_revision = 1; 00493 if(h->stream_revision > 0) 00494 skip_bits(&s->gb,1); //marker_bit 00495 } 00496 /* release last B frame */ 00497 if(h->picture.data[0]) 00498 s->avctx->release_buffer(s->avctx, (AVFrame *)&h->picture); 00499 00500 s->avctx->get_buffer(s->avctx, (AVFrame *)&h->picture); 00501 ff_cavs_init_pic(h); 00502 h->picture.poc = get_bits(&s->gb,8)*2; 00503 00504 /* get temporal distances and MV scaling factors */ 00505 if(h->pic_type != FF_B_TYPE) { 00506 h->dist[0] = (h->picture.poc - h->DPB[0].poc + 512) % 512; 00507 } else { 00508 h->dist[0] = (h->DPB[0].poc - h->picture.poc + 512) % 512; 00509 } 00510 h->dist[1] = (h->picture.poc - h->DPB[1].poc + 512) % 512; 00511 h->scale_den[0] = h->dist[0] ? 512/h->dist[0] : 0; 00512 h->scale_den[1] = h->dist[1] ? 512/h->dist[1] : 0; 00513 if(h->pic_type == FF_B_TYPE) { 00514 h->sym_factor = h->dist[0]*h->scale_den[1]; 00515 } else { 00516 h->direct_den[0] = h->dist[0] ? 16384/h->dist[0] : 0; 00517 h->direct_den[1] = h->dist[1] ? 16384/h->dist[1] : 0; 00518 } 00519 00520 if(s->low_delay) 00521 get_ue_golomb(&s->gb); //bbv_check_times 00522 h->progressive = get_bits1(&s->gb); 00523 h->pic_structure = 1; 00524 if(!h->progressive) 00525 h->pic_structure = get_bits1(&s->gb); 00526 if(!h->pic_structure && h->stc == PIC_PB_START_CODE) 00527 skip_bits1(&s->gb); //advanced_pred_mode_disable 00528 skip_bits1(&s->gb); //top_field_first 00529 skip_bits1(&s->gb); //repeat_first_field 00530 h->qp_fixed = get_bits1(&s->gb); 00531 h->qp = get_bits(&s->gb,6); 00532 if(h->pic_type == FF_I_TYPE) { 00533 if(!h->progressive && !h->pic_structure) 00534 skip_bits1(&s->gb);//what is this? 00535 skip_bits(&s->gb,4); //reserved bits 00536 } else { 00537 if(!(h->pic_type == FF_B_TYPE && h->pic_structure == 1)) 00538 h->ref_flag = get_bits1(&s->gb); 00539 skip_bits(&s->gb,4); //reserved bits 00540 h->skip_mode_flag = get_bits1(&s->gb); 00541 } 00542 h->loop_filter_disable = get_bits1(&s->gb); 00543 if(!h->loop_filter_disable && get_bits1(&s->gb)) { 00544 h->alpha_offset = get_se_golomb(&s->gb); 00545 h->beta_offset = get_se_golomb(&s->gb); 00546 } else { 00547 h->alpha_offset = h->beta_offset = 0; 00548 } 00549 if(h->pic_type == FF_I_TYPE) { 00550 do { 00551 check_for_slice(h); 00552 decode_mb_i(h, 0); 00553 } while(ff_cavs_next_mb(h)); 00554 } else if(h->pic_type == FF_P_TYPE) { 00555 do { 00556 if(check_for_slice(h)) 00557 skip_count = -1; 00558 if(h->skip_mode_flag && (skip_count < 0)) 00559 skip_count = get_ue_golomb(&s->gb); 00560 if(h->skip_mode_flag && skip_count--) { 00561 decode_mb_p(h,P_SKIP); 00562 } else { 00563 mb_type = get_ue_golomb(&s->gb) + P_SKIP + h->skip_mode_flag; 00564 if(mb_type > P_8X8) 00565 decode_mb_i(h, mb_type - P_8X8 - 1); 00566 else 00567 decode_mb_p(h,mb_type); 00568 } 00569 } while(ff_cavs_next_mb(h)); 00570 } else { /* FF_B_TYPE */ 00571 do { 00572 if(check_for_slice(h)) 00573 skip_count = -1; 00574 if(h->skip_mode_flag && (skip_count < 0)) 00575 skip_count = get_ue_golomb(&s->gb); 00576 if(h->skip_mode_flag && skip_count--) { 00577 decode_mb_b(h,B_SKIP); 00578 } else { 00579 mb_type = get_ue_golomb(&s->gb) + B_SKIP + h->skip_mode_flag; 00580 if(mb_type > B_8X8) 00581 decode_mb_i(h, mb_type - B_8X8 - 1); 00582 else 00583 decode_mb_b(h,mb_type); 00584 } 00585 } while(ff_cavs_next_mb(h)); 00586 } 00587 if(h->pic_type != FF_B_TYPE) { 00588 if(h->DPB[1].data[0]) 00589 s->avctx->release_buffer(s->avctx, (AVFrame *)&h->DPB[1]); 00590 h->DPB[1] = h->DPB[0]; 00591 h->DPB[0] = h->picture; 00592 memset(&h->picture,0,sizeof(Picture)); 00593 } 00594 return 0; 00595 } 00596 00597 /***************************************************************************** 00598 * 00599 * headers and interface 00600 * 00601 ****************************************************************************/ 00602 00603 static int decode_seq_header(AVSContext *h) { 00604 MpegEncContext *s = &h->s; 00605 int frame_rate_code; 00606 00607 h->profile = get_bits(&s->gb,8); 00608 h->level = get_bits(&s->gb,8); 00609 skip_bits1(&s->gb); //progressive sequence 00610 s->width = get_bits(&s->gb,14); 00611 s->height = get_bits(&s->gb,14); 00612 skip_bits(&s->gb,2); //chroma format 00613 skip_bits(&s->gb,3); //sample_precision 00614 h->aspect_ratio = get_bits(&s->gb,4); 00615 frame_rate_code = get_bits(&s->gb,4); 00616 skip_bits(&s->gb,18);//bit_rate_lower 00617 skip_bits1(&s->gb); //marker_bit 00618 skip_bits(&s->gb,12);//bit_rate_upper 00619 s->low_delay = get_bits1(&s->gb); 00620 h->mb_width = (s->width + 15) >> 4; 00621 h->mb_height = (s->height + 15) >> 4; 00622 h->s.avctx->time_base.den = ff_frame_rate_tab[frame_rate_code].num; 00623 h->s.avctx->time_base.num = ff_frame_rate_tab[frame_rate_code].den; 00624 h->s.avctx->width = s->width; 00625 h->s.avctx->height = s->height; 00626 if(!h->top_qp) 00627 ff_cavs_init_top_lines(h); 00628 return 0; 00629 } 00630 00631 static void cavs_flush(AVCodecContext * avctx) { 00632 AVSContext *h = avctx->priv_data; 00633 h->got_keyframe = 0; 00634 } 00635 00636 static int cavs_decode_frame(AVCodecContext * avctx,void *data, int *data_size, 00637 AVPacket *avpkt) { 00638 const uint8_t *buf = avpkt->data; 00639 int buf_size = avpkt->size; 00640 AVSContext *h = avctx->priv_data; 00641 MpegEncContext *s = &h->s; 00642 int input_size; 00643 const uint8_t *buf_end; 00644 const uint8_t *buf_ptr; 00645 AVFrame *picture = data; 00646 uint32_t stc = -1; 00647 00648 s->avctx = avctx; 00649 00650 if (buf_size == 0) { 00651 if(!s->low_delay && h->DPB[0].data[0]) { 00652 *data_size = sizeof(AVPicture); 00653 *picture = *(AVFrame *) &h->DPB[0]; 00654 } 00655 return 0; 00656 } 00657 00658 buf_ptr = buf; 00659 buf_end = buf + buf_size; 00660 for(;;) { 00661 buf_ptr = ff_find_start_code(buf_ptr,buf_end, &stc); 00662 if(stc & 0xFFFFFE00) 00663 return FFMAX(0, buf_ptr - buf - s->parse_context.last_index); 00664 input_size = (buf_end - buf_ptr)*8; 00665 switch(stc) { 00666 case CAVS_START_CODE: 00667 init_get_bits(&s->gb, buf_ptr, input_size); 00668 decode_seq_header(h); 00669 break; 00670 case PIC_I_START_CODE: 00671 if(!h->got_keyframe) { 00672 if(h->DPB[0].data[0]) 00673 avctx->release_buffer(avctx, (AVFrame *)&h->DPB[0]); 00674 if(h->DPB[1].data[0]) 00675 avctx->release_buffer(avctx, (AVFrame *)&h->DPB[1]); 00676 h->got_keyframe = 1; 00677 } 00678 case PIC_PB_START_CODE: 00679 *data_size = 0; 00680 if(!h->got_keyframe) 00681 break; 00682 init_get_bits(&s->gb, buf_ptr, input_size); 00683 h->stc = stc; 00684 if(decode_pic(h)) 00685 break; 00686 *data_size = sizeof(AVPicture); 00687 if(h->pic_type != FF_B_TYPE) { 00688 if(h->DPB[1].data[0]) { 00689 *picture = *(AVFrame *) &h->DPB[1]; 00690 } else { 00691 *data_size = 0; 00692 } 00693 } else 00694 *picture = *(AVFrame *) &h->picture; 00695 break; 00696 case EXT_START_CODE: 00697 //mpeg_decode_extension(avctx,buf_ptr, input_size); 00698 break; 00699 case USER_START_CODE: 00700 //mpeg_decode_user_data(avctx,buf_ptr, input_size); 00701 break; 00702 default: 00703 if (stc <= SLICE_MAX_START_CODE) { 00704 init_get_bits(&s->gb, buf_ptr, input_size); 00705 decode_slice_header(h, &s->gb); 00706 } 00707 break; 00708 } 00709 } 00710 } 00711 00712 AVCodec cavs_decoder = { 00713 "cavs", 00714 AVMEDIA_TYPE_VIDEO, 00715 CODEC_ID_CAVS, 00716 sizeof(AVSContext), 00717 ff_cavs_init, 00718 NULL, 00719 ff_cavs_end, 00720 cavs_decode_frame, 00721 CODEC_CAP_DR1 | CODEC_CAP_DELAY, 00722 .flush= cavs_flush, 00723 .long_name= NULL_IF_CONFIG_SMALL("Chinese AVS video (AVS1-P2, JiZhun profile)"), 00724 };