static int rv40_decode_intra_types(RV34DecContext *r, GetBitContext *gb, int8_t *dst) { MpegEncContext *s = &r->s; int i, j, k, v; int A, B, C; int pattern; int8_t *ptr; for(i = 0; i < 4; i++, dst += r->intra_types_stride){ if(!i && s->first_slice_line){ pattern = get_vlc2(gb, aic_top_vlc.table, AIC_TOP_BITS, 1); dst[0] = (pattern >> 2) & 2; dst[1] = (pattern >> 1) & 2; dst[2] = pattern & 2; dst[3] = (pattern << 1) & 2; continue; } ptr = dst; for(j = 0; j < 4; j++){ /* Coefficients are read using VLC chosen by the prediction pattern * The first one (used for retrieving a pair of coefficients) is * constructed from the top, top right and left coefficients * The second one (used for retrieving only one coefficient) is * top + 10 * left. */ A = ptr[-r->intra_types_stride + 1]; // it won't be used for the last coefficient in a row B = ptr[-r->intra_types_stride]; C = ptr[-1]; pattern = A + (B << 4) + (C << 8); for(k = 0; k < MODE2_PATTERNS_NUM; k++) if(pattern == rv40_aic_table_index[k]) break; if(j < 3 && k < MODE2_PATTERNS_NUM){ //pattern is found, decoding 2 coefficients v = get_vlc2(gb, aic_mode2_vlc[k].table, AIC_MODE2_BITS, 2); *ptr++ = v/9; *ptr++ = v%9; j++; }else{ if(B != -1 && C != -1) v = get_vlc2(gb, aic_mode1_vlc[B + C*10].table, AIC_MODE1_BITS, 1); else{ // tricky decoding v = 0; switch(C){ case -1: // code 0 -> 1, 1 -> 0 if(B < 2) v = get_bits1(gb) ^ 1; break; case 0: case 2: // code 0 -> 2, 1 -> 0 v = (get_bits1(gb) ^ 1) << 1; break; } } *ptr++ = v; } } } return 0; }