Libav 0.7.1
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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 Libav. 00006 * 00007 * Libav 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 * Libav 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 Libav; 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 if (level_code >= 0) { 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 } else { 00140 break; 00141 } 00142 level_buf[i] = level; 00143 run_buf[i] = run; 00144 } 00145 if(dequant(h,level_buf, run_buf, block, ff_cavs_dequant_mul[qp], 00146 ff_cavs_dequant_shift[qp], i)) 00147 return -1; 00148 h->cdsp.cavs_idct8_add(dst,block,stride); 00149 h->s.dsp.clear_block(block); 00150 return 0; 00151 } 00152 00153 00154 static inline void decode_residual_chroma(AVSContext *h) { 00155 if(h->cbp & (1<<4)) 00156 decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0, 00157 ff_cavs_chroma_qp[h->qp],h->cu,h->c_stride); 00158 if(h->cbp & (1<<5)) 00159 decode_residual_block(h,&h->s.gb,ff_cavs_chroma_dec,0, 00160 ff_cavs_chroma_qp[h->qp],h->cv,h->c_stride); 00161 } 00162 00163 static inline int decode_residual_inter(AVSContext *h) { 00164 int block; 00165 00166 /* get coded block pattern */ 00167 int cbp= get_ue_golomb(&h->s.gb); 00168 if(cbp > 63){ 00169 av_log(h->s.avctx, AV_LOG_ERROR, "illegal inter cbp\n"); 00170 return -1; 00171 } 00172 h->cbp = cbp_tab[cbp][1]; 00173 00174 /* get quantizer */ 00175 if(h->cbp && !h->qp_fixed) 00176 h->qp = (h->qp + get_se_golomb(&h->s.gb)) & 63; 00177 for(block=0;block<4;block++) 00178 if(h->cbp & (1<<block)) 00179 decode_residual_block(h,&h->s.gb,ff_cavs_inter_dec,0,h->qp, 00180 h->cy + h->luma_scan[block], h->l_stride); 00181 decode_residual_chroma(h); 00182 00183 return 0; 00184 } 00185 00186 /***************************************************************************** 00187 * 00188 * macroblock level 00189 * 00190 ****************************************************************************/ 00191 00192 static int decode_mb_i(AVSContext *h, int cbp_code) { 00193 GetBitContext *gb = &h->s.gb; 00194 unsigned pred_mode_uv; 00195 int block; 00196 uint8_t top[18]; 00197 uint8_t *left = NULL; 00198 uint8_t *d; 00199 00200 ff_cavs_init_mb(h); 00201 00202 /* get intra prediction modes from stream */ 00203 for(block=0;block<4;block++) { 00204 int nA,nB,predpred; 00205 int pos = ff_cavs_scan3x3[block]; 00206 00207 nA = h->pred_mode_Y[pos-1]; 00208 nB = h->pred_mode_Y[pos-3]; 00209 predpred = FFMIN(nA,nB); 00210 if(predpred == NOT_AVAIL) // if either is not available 00211 predpred = INTRA_L_LP; 00212 if(!get_bits1(gb)){ 00213 int rem_mode= get_bits(gb, 2); 00214 predpred = rem_mode + (rem_mode >= predpred); 00215 } 00216 h->pred_mode_Y[pos] = predpred; 00217 } 00218 pred_mode_uv = get_ue_golomb(gb); 00219 if(pred_mode_uv > 6) { 00220 av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra chroma pred mode\n"); 00221 return -1; 00222 } 00223 ff_cavs_modify_mb_i(h, &pred_mode_uv); 00224 00225 /* get coded block pattern */ 00226 if(h->pic_type == AV_PICTURE_TYPE_I) 00227 cbp_code = get_ue_golomb(gb); 00228 if(cbp_code > 63){ 00229 av_log(h->s.avctx, AV_LOG_ERROR, "illegal intra cbp\n"); 00230 return -1; 00231 } 00232 h->cbp = cbp_tab[cbp_code][0]; 00233 if(h->cbp && !h->qp_fixed) 00234 h->qp = (h->qp + get_se_golomb(gb)) & 63; //qp_delta 00235 00236 /* luma intra prediction interleaved with residual decode/transform/add */ 00237 for(block=0;block<4;block++) { 00238 d = h->cy + h->luma_scan[block]; 00239 ff_cavs_load_intra_pred_luma(h, top, &left, block); 00240 h->intra_pred_l[h->pred_mode_Y[ff_cavs_scan3x3[block]]] 00241 (d, top, left, h->l_stride); 00242 if(h->cbp & (1<<block)) 00243 decode_residual_block(h,gb,ff_cavs_intra_dec,1,h->qp,d,h->l_stride); 00244 } 00245 00246 /* chroma intra prediction */ 00247 ff_cavs_load_intra_pred_chroma(h); 00248 h->intra_pred_c[pred_mode_uv](h->cu, &h->top_border_u[h->mbx*10], 00249 h->left_border_u, h->c_stride); 00250 h->intra_pred_c[pred_mode_uv](h->cv, &h->top_border_v[h->mbx*10], 00251 h->left_border_v, h->c_stride); 00252 00253 decode_residual_chroma(h); 00254 ff_cavs_filter(h,I_8X8); 00255 set_mv_intra(h); 00256 return 0; 00257 } 00258 00259 static void decode_mb_p(AVSContext *h, enum cavs_mb mb_type) { 00260 GetBitContext *gb = &h->s.gb; 00261 int ref[4]; 00262 00263 ff_cavs_init_mb(h); 00264 switch(mb_type) { 00265 case P_SKIP: 00266 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_PSKIP, BLK_16X16, 0); 00267 break; 00268 case P_16X16: 00269 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00270 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16,ref[0]); 00271 break; 00272 case P_16X8: 00273 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00274 ref[2] = h->ref_flag ? 0 : get_bits1(gb); 00275 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, ref[0]); 00276 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, ref[2]); 00277 break; 00278 case P_8X16: 00279 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00280 ref[1] = h->ref_flag ? 0 : get_bits1(gb); 00281 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, ref[0]); 00282 ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_TOPRIGHT,BLK_8X16, ref[1]); 00283 break; 00284 case P_8X8: 00285 ref[0] = h->ref_flag ? 0 : get_bits1(gb); 00286 ref[1] = h->ref_flag ? 0 : get_bits1(gb); 00287 ref[2] = h->ref_flag ? 0 : get_bits1(gb); 00288 ref[3] = h->ref_flag ? 0 : get_bits1(gb); 00289 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_MEDIAN, BLK_8X8, ref[0]); 00290 ff_cavs_mv(h, MV_FWD_X1, MV_FWD_C2, MV_PRED_MEDIAN, BLK_8X8, ref[1]); 00291 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_X1, MV_PRED_MEDIAN, BLK_8X8, ref[2]); 00292 ff_cavs_mv(h, MV_FWD_X3, MV_FWD_X0, MV_PRED_MEDIAN, BLK_8X8, ref[3]); 00293 } 00294 ff_cavs_inter(h, mb_type); 00295 set_intra_mode_default(h); 00296 store_mvs(h); 00297 if(mb_type != P_SKIP) 00298 decode_residual_inter(h); 00299 ff_cavs_filter(h,mb_type); 00300 h->col_type_base[h->mbidx] = mb_type; 00301 } 00302 00303 static void decode_mb_b(AVSContext *h, enum cavs_mb mb_type) { 00304 int block; 00305 enum cavs_sub_mb sub_type[4]; 00306 int flags; 00307 00308 ff_cavs_init_mb(h); 00309 00310 /* reset all MVs */ 00311 h->mv[MV_FWD_X0] = ff_cavs_dir_mv; 00312 set_mvs(&h->mv[MV_FWD_X0], BLK_16X16); 00313 h->mv[MV_BWD_X0] = ff_cavs_dir_mv; 00314 set_mvs(&h->mv[MV_BWD_X0], BLK_16X16); 00315 switch(mb_type) { 00316 case B_SKIP: 00317 case B_DIRECT: 00318 if(!h->col_type_base[h->mbidx]) { 00319 /* intra MB at co-location, do in-plane prediction */ 00320 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_BSKIP, BLK_16X16, 1); 00321 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_BSKIP, BLK_16X16, 0); 00322 } else 00323 /* direct prediction from co-located P MB, block-wise */ 00324 for(block=0;block<4;block++) 00325 mv_pred_direct(h,&h->mv[mv_scan[block]], 00326 &h->col_mv[h->mbidx*4 + block]); 00327 break; 00328 case B_FWD_16X16: 00329 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1); 00330 break; 00331 case B_SYM_16X16: 00332 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_MEDIAN, BLK_16X16, 1); 00333 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X16); 00334 break; 00335 case B_BWD_16X16: 00336 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_MEDIAN, BLK_16X16, 0); 00337 break; 00338 case B_8X8: 00339 for(block=0;block<4;block++) 00340 sub_type[block] = get_bits(&h->s.gb,2); 00341 for(block=0;block<4;block++) { 00342 switch(sub_type[block]) { 00343 case B_SUB_DIRECT: 00344 if(!h->col_type_base[h->mbidx]) { 00345 /* intra MB at co-location, do in-plane prediction */ 00346 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3, 00347 MV_PRED_BSKIP, BLK_8X8, 1); 00348 ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS, 00349 mv_scan[block]-3+MV_BWD_OFFS, 00350 MV_PRED_BSKIP, BLK_8X8, 0); 00351 } else 00352 mv_pred_direct(h,&h->mv[mv_scan[block]], 00353 &h->col_mv[h->mbidx*4 + block]); 00354 break; 00355 case B_SUB_FWD: 00356 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3, 00357 MV_PRED_MEDIAN, BLK_8X8, 1); 00358 break; 00359 case B_SUB_SYM: 00360 ff_cavs_mv(h, mv_scan[block], mv_scan[block]-3, 00361 MV_PRED_MEDIAN, BLK_8X8, 1); 00362 mv_pred_sym(h, &h->mv[mv_scan[block]], BLK_8X8); 00363 break; 00364 } 00365 } 00366 for(block=0;block<4;block++) { 00367 if(sub_type[block] == B_SUB_BWD) 00368 ff_cavs_mv(h, mv_scan[block]+MV_BWD_OFFS, 00369 mv_scan[block]+MV_BWD_OFFS-3, 00370 MV_PRED_MEDIAN, BLK_8X8, 0); 00371 } 00372 break; 00373 default: 00374 assert((mb_type > B_SYM_16X16) && (mb_type < B_8X8)); 00375 flags = ff_cavs_partition_flags[mb_type]; 00376 if(mb_type & 1) { /* 16x8 macroblock types */ 00377 if(flags & FWD0) 00378 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_C2, MV_PRED_TOP, BLK_16X8, 1); 00379 if(flags & SYM0) 00380 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_16X8); 00381 if(flags & FWD1) 00382 ff_cavs_mv(h, MV_FWD_X2, MV_FWD_A1, MV_PRED_LEFT, BLK_16X8, 1); 00383 if(flags & SYM1) 00384 mv_pred_sym(h, &h->mv[MV_FWD_X2], BLK_16X8); 00385 if(flags & BWD0) 00386 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_C2, MV_PRED_TOP, BLK_16X8, 0); 00387 if(flags & BWD1) 00388 ff_cavs_mv(h, MV_BWD_X2, MV_BWD_A1, MV_PRED_LEFT, BLK_16X8, 0); 00389 } else { /* 8x16 macroblock types */ 00390 if(flags & FWD0) 00391 ff_cavs_mv(h, MV_FWD_X0, MV_FWD_B3, MV_PRED_LEFT, BLK_8X16, 1); 00392 if(flags & SYM0) 00393 mv_pred_sym(h, &h->mv[MV_FWD_X0], BLK_8X16); 00394 if(flags & FWD1) 00395 ff_cavs_mv(h,MV_FWD_X1,MV_FWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,1); 00396 if(flags & SYM1) 00397 mv_pred_sym(h, &h->mv[MV_FWD_X1], BLK_8X16); 00398 if(flags & BWD0) 00399 ff_cavs_mv(h, MV_BWD_X0, MV_BWD_B3, MV_PRED_LEFT, BLK_8X16, 0); 00400 if(flags & BWD1) 00401 ff_cavs_mv(h,MV_BWD_X1,MV_BWD_C2,MV_PRED_TOPRIGHT,BLK_8X16,0); 00402 } 00403 } 00404 ff_cavs_inter(h, mb_type); 00405 set_intra_mode_default(h); 00406 if(mb_type != B_SKIP) 00407 decode_residual_inter(h); 00408 ff_cavs_filter(h,mb_type); 00409 } 00410 00411 /***************************************************************************** 00412 * 00413 * slice level 00414 * 00415 ****************************************************************************/ 00416 00417 static inline int decode_slice_header(AVSContext *h, GetBitContext *gb) { 00418 if(h->stc > 0xAF) 00419 av_log(h->s.avctx, AV_LOG_ERROR, "unexpected start code 0x%02x\n", h->stc); 00420 h->mby = h->stc; 00421 h->mbidx = h->mby*h->mb_width; 00422 00423 /* mark top macroblocks as unavailable */ 00424 h->flags &= ~(B_AVAIL|C_AVAIL); 00425 if((h->mby == 0) && (!h->qp_fixed)){ 00426 h->qp_fixed = get_bits1(gb); 00427 h->qp = get_bits(gb,6); 00428 } 00429 /* inter frame or second slice can have weighting params */ 00430 if((h->pic_type != AV_PICTURE_TYPE_I) || (!h->pic_structure && h->mby >= h->mb_width/2)) 00431 if(get_bits1(gb)) { //slice_weighting_flag 00432 av_log(h->s.avctx, AV_LOG_ERROR, 00433 "weighted prediction not yet supported\n"); 00434 } 00435 return 0; 00436 } 00437 00438 static inline int check_for_slice(AVSContext *h) { 00439 GetBitContext *gb = &h->s.gb; 00440 int align; 00441 00442 if(h->mbx) 00443 return 0; 00444 align = (-get_bits_count(gb)) & 7; 00445 /* check for stuffing byte */ 00446 if(!align && (show_bits(gb,8) == 0x80)) 00447 align = 8; 00448 if((show_bits_long(gb,24+align) & 0xFFFFFF) == 0x000001) { 00449 skip_bits_long(gb,24+align); 00450 h->stc = get_bits(gb,8); 00451 if (h->stc >= h->mb_height) 00452 return 0; 00453 decode_slice_header(h,gb); 00454 return 1; 00455 } 00456 return 0; 00457 } 00458 00459 /***************************************************************************** 00460 * 00461 * frame level 00462 * 00463 ****************************************************************************/ 00464 00465 static int decode_pic(AVSContext *h) { 00466 MpegEncContext *s = &h->s; 00467 int skip_count = -1; 00468 enum cavs_mb mb_type; 00469 00470 if (!s->context_initialized) { 00471 s->avctx->idct_algo = FF_IDCT_CAVS; 00472 if (MPV_common_init(s) < 0) 00473 return -1; 00474 ff_init_scantable(s->dsp.idct_permutation,&h->scantable,ff_zigzag_direct); 00475 } 00476 skip_bits(&s->gb,16);//bbv_dwlay 00477 if(h->stc == PIC_PB_START_CODE) { 00478 h->pic_type = get_bits(&s->gb,2) + AV_PICTURE_TYPE_I; 00479 if(h->pic_type > AV_PICTURE_TYPE_B) { 00480 av_log(s->avctx, AV_LOG_ERROR, "illegal picture type\n"); 00481 return -1; 00482 } 00483 /* make sure we have the reference frames we need */ 00484 if(!h->DPB[0].data[0] || 00485 (!h->DPB[1].data[0] && h->pic_type == AV_PICTURE_TYPE_B)) 00486 return -1; 00487 } else { 00488 h->pic_type = AV_PICTURE_TYPE_I; 00489 if(get_bits1(&s->gb)) 00490 skip_bits(&s->gb,24);//time_code 00491 /* old sample clips were all progressive and no low_delay, 00492 bump stream revision if detected otherwise */ 00493 if((s->low_delay) || !(show_bits(&s->gb,9) & 1)) 00494 h->stream_revision = 1; 00495 /* similarly test top_field_first and repeat_first_field */ 00496 else if(show_bits(&s->gb,11) & 3) 00497 h->stream_revision = 1; 00498 if(h->stream_revision > 0) 00499 skip_bits(&s->gb,1); //marker_bit 00500 } 00501 /* release last B frame */ 00502 if(h->picture.data[0]) 00503 s->avctx->release_buffer(s->avctx, (AVFrame *)&h->picture); 00504 00505 s->avctx->get_buffer(s->avctx, (AVFrame *)&h->picture); 00506 ff_cavs_init_pic(h); 00507 h->picture.poc = get_bits(&s->gb,8)*2; 00508 00509 /* get temporal distances and MV scaling factors */ 00510 if(h->pic_type != AV_PICTURE_TYPE_B) { 00511 h->dist[0] = (h->picture.poc - h->DPB[0].poc + 512) % 512; 00512 } else { 00513 h->dist[0] = (h->DPB[0].poc - h->picture.poc + 512) % 512; 00514 } 00515 h->dist[1] = (h->picture.poc - h->DPB[1].poc + 512) % 512; 00516 h->scale_den[0] = h->dist[0] ? 512/h->dist[0] : 0; 00517 h->scale_den[1] = h->dist[1] ? 512/h->dist[1] : 0; 00518 if(h->pic_type == AV_PICTURE_TYPE_B) { 00519 h->sym_factor = h->dist[0]*h->scale_den[1]; 00520 } else { 00521 h->direct_den[0] = h->dist[0] ? 16384/h->dist[0] : 0; 00522 h->direct_den[1] = h->dist[1] ? 16384/h->dist[1] : 0; 00523 } 00524 00525 if(s->low_delay) 00526 get_ue_golomb(&s->gb); //bbv_check_times 00527 h->progressive = get_bits1(&s->gb); 00528 h->pic_structure = 1; 00529 if(!h->progressive) 00530 h->pic_structure = get_bits1(&s->gb); 00531 if(!h->pic_structure && h->stc == PIC_PB_START_CODE) 00532 skip_bits1(&s->gb); //advanced_pred_mode_disable 00533 skip_bits1(&s->gb); //top_field_first 00534 skip_bits1(&s->gb); //repeat_first_field 00535 h->qp_fixed = get_bits1(&s->gb); 00536 h->qp = get_bits(&s->gb,6); 00537 if(h->pic_type == AV_PICTURE_TYPE_I) { 00538 if(!h->progressive && !h->pic_structure) 00539 skip_bits1(&s->gb);//what is this? 00540 skip_bits(&s->gb,4); //reserved bits 00541 } else { 00542 if(!(h->pic_type == AV_PICTURE_TYPE_B && h->pic_structure == 1)) 00543 h->ref_flag = get_bits1(&s->gb); 00544 skip_bits(&s->gb,4); //reserved bits 00545 h->skip_mode_flag = get_bits1(&s->gb); 00546 } 00547 h->loop_filter_disable = get_bits1(&s->gb); 00548 if(!h->loop_filter_disable && get_bits1(&s->gb)) { 00549 h->alpha_offset = get_se_golomb(&s->gb); 00550 h->beta_offset = get_se_golomb(&s->gb); 00551 } else { 00552 h->alpha_offset = h->beta_offset = 0; 00553 } 00554 if(h->pic_type == AV_PICTURE_TYPE_I) { 00555 do { 00556 check_for_slice(h); 00557 decode_mb_i(h, 0); 00558 } while(ff_cavs_next_mb(h)); 00559 } else if(h->pic_type == AV_PICTURE_TYPE_P) { 00560 do { 00561 if(check_for_slice(h)) 00562 skip_count = -1; 00563 if(h->skip_mode_flag && (skip_count < 0)) 00564 skip_count = get_ue_golomb(&s->gb); 00565 if(h->skip_mode_flag && skip_count--) { 00566 decode_mb_p(h,P_SKIP); 00567 } else { 00568 mb_type = get_ue_golomb(&s->gb) + P_SKIP + h->skip_mode_flag; 00569 if(mb_type > P_8X8) 00570 decode_mb_i(h, mb_type - P_8X8 - 1); 00571 else 00572 decode_mb_p(h,mb_type); 00573 } 00574 } while(ff_cavs_next_mb(h)); 00575 } else { /* AV_PICTURE_TYPE_B */ 00576 do { 00577 if(check_for_slice(h)) 00578 skip_count = -1; 00579 if(h->skip_mode_flag && (skip_count < 0)) 00580 skip_count = get_ue_golomb(&s->gb); 00581 if(h->skip_mode_flag && skip_count--) { 00582 decode_mb_b(h,B_SKIP); 00583 } else { 00584 mb_type = get_ue_golomb(&s->gb) + B_SKIP + h->skip_mode_flag; 00585 if(mb_type > B_8X8) 00586 decode_mb_i(h, mb_type - B_8X8 - 1); 00587 else 00588 decode_mb_b(h,mb_type); 00589 } 00590 } while(ff_cavs_next_mb(h)); 00591 } 00592 if(h->pic_type != AV_PICTURE_TYPE_B) { 00593 if(h->DPB[1].data[0]) 00594 s->avctx->release_buffer(s->avctx, (AVFrame *)&h->DPB[1]); 00595 h->DPB[1] = h->DPB[0]; 00596 h->DPB[0] = h->picture; 00597 memset(&h->picture,0,sizeof(Picture)); 00598 } 00599 return 0; 00600 } 00601 00602 /***************************************************************************** 00603 * 00604 * headers and interface 00605 * 00606 ****************************************************************************/ 00607 00608 static int decode_seq_header(AVSContext *h) { 00609 MpegEncContext *s = &h->s; 00610 int frame_rate_code; 00611 00612 h->profile = get_bits(&s->gb,8); 00613 h->level = get_bits(&s->gb,8); 00614 skip_bits1(&s->gb); //progressive sequence 00615 s->width = get_bits(&s->gb,14); 00616 s->height = get_bits(&s->gb,14); 00617 skip_bits(&s->gb,2); //chroma format 00618 skip_bits(&s->gb,3); //sample_precision 00619 h->aspect_ratio = get_bits(&s->gb,4); 00620 frame_rate_code = get_bits(&s->gb,4); 00621 skip_bits(&s->gb,18);//bit_rate_lower 00622 skip_bits1(&s->gb); //marker_bit 00623 skip_bits(&s->gb,12);//bit_rate_upper 00624 s->low_delay = get_bits1(&s->gb); 00625 h->mb_width = (s->width + 15) >> 4; 00626 h->mb_height = (s->height + 15) >> 4; 00627 h->s.avctx->time_base.den = ff_frame_rate_tab[frame_rate_code].num; 00628 h->s.avctx->time_base.num = ff_frame_rate_tab[frame_rate_code].den; 00629 h->s.avctx->width = s->width; 00630 h->s.avctx->height = s->height; 00631 if(!h->top_qp) 00632 ff_cavs_init_top_lines(h); 00633 return 0; 00634 } 00635 00636 static void cavs_flush(AVCodecContext * avctx) { 00637 AVSContext *h = avctx->priv_data; 00638 h->got_keyframe = 0; 00639 } 00640 00641 static int cavs_decode_frame(AVCodecContext * avctx,void *data, int *data_size, 00642 AVPacket *avpkt) { 00643 const uint8_t *buf = avpkt->data; 00644 int buf_size = avpkt->size; 00645 AVSContext *h = avctx->priv_data; 00646 MpegEncContext *s = &h->s; 00647 int input_size; 00648 const uint8_t *buf_end; 00649 const uint8_t *buf_ptr; 00650 AVFrame *picture = data; 00651 uint32_t stc = -1; 00652 00653 s->avctx = avctx; 00654 00655 if (buf_size == 0) { 00656 if(!s->low_delay && h->DPB[0].data[0]) { 00657 *data_size = sizeof(AVPicture); 00658 *picture = *(AVFrame *) &h->DPB[0]; 00659 } 00660 return 0; 00661 } 00662 00663 buf_ptr = buf; 00664 buf_end = buf + buf_size; 00665 for(;;) { 00666 buf_ptr = ff_find_start_code(buf_ptr,buf_end, &stc); 00667 if((stc & 0xFFFFFE00) || buf_ptr == buf_end) 00668 return FFMAX(0, buf_ptr - buf - s->parse_context.last_index); 00669 input_size = (buf_end - buf_ptr)*8; 00670 switch(stc) { 00671 case CAVS_START_CODE: 00672 init_get_bits(&s->gb, buf_ptr, input_size); 00673 decode_seq_header(h); 00674 break; 00675 case PIC_I_START_CODE: 00676 if(!h->got_keyframe) { 00677 if(h->DPB[0].data[0]) 00678 avctx->release_buffer(avctx, (AVFrame *)&h->DPB[0]); 00679 if(h->DPB[1].data[0]) 00680 avctx->release_buffer(avctx, (AVFrame *)&h->DPB[1]); 00681 h->got_keyframe = 1; 00682 } 00683 case PIC_PB_START_CODE: 00684 *data_size = 0; 00685 if(!h->got_keyframe) 00686 break; 00687 init_get_bits(&s->gb, buf_ptr, input_size); 00688 h->stc = stc; 00689 if(decode_pic(h)) 00690 break; 00691 *data_size = sizeof(AVPicture); 00692 if(h->pic_type != AV_PICTURE_TYPE_B) { 00693 if(h->DPB[1].data[0]) { 00694 *picture = *(AVFrame *) &h->DPB[1]; 00695 } else { 00696 *data_size = 0; 00697 } 00698 } else 00699 *picture = *(AVFrame *) &h->picture; 00700 break; 00701 case EXT_START_CODE: 00702 //mpeg_decode_extension(avctx,buf_ptr, input_size); 00703 break; 00704 case USER_START_CODE: 00705 //mpeg_decode_user_data(avctx,buf_ptr, input_size); 00706 break; 00707 default: 00708 if (stc <= SLICE_MAX_START_CODE) { 00709 init_get_bits(&s->gb, buf_ptr, input_size); 00710 decode_slice_header(h, &s->gb); 00711 } 00712 break; 00713 } 00714 } 00715 } 00716 00717 AVCodec ff_cavs_decoder = { 00718 "cavs", 00719 AVMEDIA_TYPE_VIDEO, 00720 CODEC_ID_CAVS, 00721 sizeof(AVSContext), 00722 ff_cavs_init, 00723 NULL, 00724 ff_cavs_end, 00725 cavs_decode_frame, 00726 CODEC_CAP_DR1 | CODEC_CAP_DELAY, 00727 .flush= cavs_flush, 00728 .long_name= NULL_IF_CONFIG_SMALL("Chinese AVS video (AVS1-P2, JiZhun profile)"), 00729 };