static int ivi_decode_blocks(GetBitContext *gb, IVIBandDesc *band, IVITile *tile, AVCodecContext *avctx) { int mbn, blk, num_blocks, num_coeffs, blk_size, scan_pos, run, val, pos, is_intra, mc_type = 0, mv_x, mv_y, col_mask; uint8_t col_flags[8]; int32_t prev_dc, trvec[64]; uint32_t cbp, sym, lo, hi, quant, buf_offs, q; IVIMbInfo *mb; RVMapDesc *rvmap = band->rv_map; void (*mc_with_delta_func)(int16_t *buf, const int16_t *ref_buf, uint32_t pitch, int mc_type); void (*mc_no_delta_func) (int16_t *buf, const int16_t *ref_buf, uint32_t pitch, int mc_type); const uint16_t *base_tab; const uint8_t *scale_tab; prev_dc = 0; /* init intra prediction for the DC coefficient */ blk_size = band->blk_size; col_mask = blk_size - 1; /* column mask for tracking non-zero coeffs */ num_blocks = (band->mb_size != blk_size) ? 4 : 1; /* number of blocks per mb */ num_coeffs = blk_size * blk_size; if (blk_size == 8) { mc_with_delta_func = ff_ivi_mc_8x8_delta; mc_no_delta_func = ff_ivi_mc_8x8_no_delta; } else { mc_with_delta_func = ff_ivi_mc_4x4_delta; mc_no_delta_func = ff_ivi_mc_4x4_no_delta; for (mbn = 0, mb = tile->mbs; mbn < tile->num_MBs; mb++, mbn++) { is_intra = !mb->type; cbp = mb->cbp; buf_offs = mb->buf_offs; quant = av_clip(band->glob_quant + mb->q_delta, 0, 23); base_tab = is_intra ? band->intra_base : band->inter_base; scale_tab = is_intra ? band->intra_scale : band->inter_scale; if (scale_tab) quant = scale_tab[quant]; if (!is_intra) { mv_x = mb->mv_x; mv_y = mb->mv_y; if (band->is_halfpel) { mc_type = ((mv_y & 1) << 1) | (mv_x & 1); mv_x >>= 1; mv_y >>= 1; /* convert halfpel vectors into fullpel ones */ if (mb->type) { int dmv_x, dmv_y, cx, cy; dmv_x = mb->mv_x >> band->is_halfpel; dmv_y = mb->mv_y >> band->is_halfpel; cx = mb->mv_x & band->is_halfpel; cy = mb->mv_y & band->is_halfpel; if ( mb->xpos + dmv_x < 0 || mb->xpos + dmv_x + band->mb_size + cx > band->pitch || mb->ypos + dmv_y < 0 || mb->ypos + dmv_y + band->mb_size + cy > band->aheight) { for (blk = 0; blk < num_blocks; blk++) { /* adjust block position in the buffer according to its number */ if (blk & 1) { buf_offs += blk_size; } else if (blk == 2) { buf_offs -= blk_size; buf_offs += blk_size * band->pitch; if (cbp & 1) { /* block coded ? */ scan_pos = -1; memset(trvec, 0, num_coeffs*sizeof(trvec[0])); /* zero transform vector */ memset(col_flags, 0, sizeof(col_flags)); /* zero column flags */ while (scan_pos <= num_coeffs) { sym = get_vlc2(gb, band->blk_vlc.tab->table, IVI_VLC_BITS, 1); if (sym == rvmap->eob_sym) break; /* End of block */ if (sym == rvmap->esc_sym) { /* Escape - run/val explicitly coded using 3 vlc codes */ run = get_vlc2(gb, band->blk_vlc.tab->table, IVI_VLC_BITS, 1) + 1; lo = get_vlc2(gb, band->blk_vlc.tab->table, IVI_VLC_BITS, 1); hi = get_vlc2(gb, band->blk_vlc.tab->table, IVI_VLC_BITS, 1); val = IVI_TOSIGNED((hi << 6) | lo); /* merge them and convert into signed val */ } else { if (sym >= 256U) { av_log(avctx, AV_LOG_ERROR, "Invalid sym encountered: %d.\n", sym); return -1; run = rvmap->runtab[sym]; val = rvmap->valtab[sym]; /* de-zigzag and dequantize */ scan_pos += run; if (scan_pos >= num_coeffs) break; pos = band->scan[scan_pos]; if (!val) av_dlog(avctx, "Val = 0 encountered!\n"); q = (base_tab[pos] * quant) >> 9; if (q > 1) val = val * q + FFSIGN(val) * (((q ^ 1) - 1) >> 1); trvec[pos] = val; col_flags[pos & col_mask] |= !!val; /* track columns containing non-zero coeffs */ }// while if (scan_pos >= num_coeffs && sym != rvmap->eob_sym) return -1; /* corrupt block data */ /* undoing DC coeff prediction for intra-blocks */ if (is_intra && band->is_2d_trans) { prev_dc += trvec[0]; trvec[0] = prev_dc; col_flags[0] |= !!prev_dc; /* apply inverse transform */ band->inv_transform(trvec, band->buf + buf_offs, band->pitch, col_flags); /* apply motion compensation */ if (!is_intra) mc_with_delta_func(band->buf + buf_offs, band->ref_buf + buf_offs + mv_y * band->pitch + mv_x, band->pitch, mc_type); } else { /* block not coded */ /* for intra blocks apply the dc slant transform */ /* for inter - perform the motion compensation without delta */ if (is_intra && band->dc_transform) { band->dc_transform(&prev_dc, band->buf + buf_offs, band->pitch, blk_size); } else mc_no_delta_func(band->buf + buf_offs, band->ref_buf + buf_offs + mv_y * band->pitch + mv_x, band->pitch, mc_type); cbp >>= 1; }// for blk }// for mbn align_get_bits(gb); return 0;