static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block, int n, int coded, int intra) { int level, i, last, run; int dc_pred_dir; RLTable * rl; RL_VLC_ELEM * rl_vlc; const UINT8 * scan_table; int qmul, qadd; if(intra) { /* DC coef */ if(s->partitioned_frame){ level = s->dc_val[0][ s->block_index[n] ]; if(n<4) level= (level + (s->y_dc_scale>>1))/s->y_dc_scale; //FIXME optimizs else level= (level + (s->c_dc_scale>>1))/s->c_dc_scale; dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_width]<<n)&32; }else{ level = mpeg4_decode_dc(s, n, &dc_pred_dir); if (level < 0) return -1; } block[0] = level; i = 0; if (!coded) goto not_coded; rl = &rl_intra; rl_vlc = rl_intra.rl_vlc[0]; if (s->ac_pred) { if (dc_pred_dir == 0) scan_table = s->intra_v_scantable.permutated; /* left */ else scan_table = s->intra_h_scantable.permutated; /* top */ } else { scan_table = s->intra_scantable.permutated; } qmul=1; qadd=0; } else { i = -1; if (!coded) { s->block_last_index[n] = i; return 0; } rl = &rl_inter; scan_table = s->intra_scantable.permutated; if(s->mpeg_quant){ qmul=1; qadd=0; rl_vlc = rl_inter.rl_vlc[0]; }else{ qmul = s->qscale << 1; qadd = (s->qscale - 1) | 1; rl_vlc = rl_inter.rl_vlc[s->qscale]; } } { OPEN_READER(re, &s->gb); for(;;) { UPDATE_CACHE(re, &s->gb); GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2); if (level==0) { int cache; cache= GET_CACHE(re, &s->gb); /* escape */ if (cache&0x80000000) { if (cache&0x40000000) { /* third escape */ SKIP_CACHE(re, &s->gb, 2); last= SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1); run= SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6); SKIP_COUNTER(re, &s->gb, 2+1+6); UPDATE_CACHE(re, &s->gb); if(SHOW_UBITS(re, &s->gb, 1)==0){ fprintf(stderr, "1. marker bit missing in 3. esc\n"); return -1; }; SKIP_CACHE(re, &s->gb, 1); level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12); if(SHOW_UBITS(re, &s->gb, 1)==0){ fprintf(stderr, "2. marker bit missing in 3. esc\n"); return -1; }; LAST_SKIP_CACHE(re, &s->gb, 1); SKIP_COUNTER(re, &s->gb, 1+12+1); if(level*s->qscale>1024 || level*s->qscale<-1024){ fprintf(stderr, "|level| overflow in 3. esc, qp=%d\n", s->qscale); return -1; } #if 1 { const int abs_level= ABS(level); if(abs_level<=MAX_LEVEL && run<=MAX_RUN && ((s->workaround_bugs&FF_BUG_AC_VLC)==0)){ const int run1= run - rl->max_run[last][abs_level] - 1; if(abs_level <= rl->max_level[last][run]){ fprintf(stderr, "illegal 3. esc, vlc encoding possible\n"); return -1; } if(abs_level <= rl->max_level[last][run]*2){ fprintf(stderr, "illegal 3. esc, esc 1 encoding possible\n"); return -1; } if(run1 >= 0 && abs_level <= rl->max_level[last][run1]){ fprintf(stderr, "illegal 3. esc, esc 2 encoding possible\n"); return -1; } } } #endif if (level>0) level= level * qmul + qadd; else level= level * qmul - qadd; i+= run + 1; if(last) i+=192; } else { /* second escape */ #if MIN_CACHE_BITS < 20 LAST_SKIP_BITS(re, &s->gb, 2); UPDATE_CACHE(re, &s->gb); #else SKIP_BITS(re, &s->gb, 2); #endif GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2); i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_BITS(re, &s->gb, 1); } } else { /* first escape */ #if MIN_CACHE_BITS < 19 LAST_SKIP_BITS(re, &s->gb, 1); UPDATE_CACHE(re, &s->gb); #else SKIP_BITS(re, &s->gb, 1); #endif GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2); i+= run; level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_BITS(re, &s->gb, 1); } } else { i+= run; level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_BITS(re, &s->gb, 1); } if (i > 62){ i-= 192; if(i&(~63)){ fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y); return -1; } block[scan_table[i]] = level; break; } block[scan_table[i]] = level; } CLOSE_READER(re, &s->gb); } not_coded: if (s->mb_intra) { mpeg4_pred_ac(s, block, n, dc_pred_dir); if (s->ac_pred) { i = 63; /* XXX: not optimal */ } } s->block_last_index[n] = i; return 0; }