static int decode_mb_info(IVI5DecContext *ctx, IVIBandDesc *band, IVITile *tile, AVCodecContext *avctx) { int x, y, mv_x, mv_y, mv_delta, offs, mb_offset, mv_scale, blks_per_mb; IVIMbInfo *mb, *ref_mb; int row_offset = band->mb_size * band->pitch; mb = tile->mbs; ref_mb = tile->ref_mbs; offs = tile->ypos * band->pitch + tile->xpos; /* scale factor for motion vectors */ mv_scale = (ctx->planes[0].bands[0].mb_size >> 3) - (band->mb_size >> 3); mv_x = mv_y = 0; for (y = tile->ypos; y < (tile->ypos + tile->height); y += band->mb_size) { mb_offset = offs; for (x = tile->xpos; x < (tile->xpos + tile->width); x += band->mb_size) { mb->xpos = x; mb->ypos = y; mb->buf_offs = mb_offset; if (get_bits1(&ctx->gb)) { if (ctx->frame_type == FRAMETYPE_INTRA) { av_log(avctx, AV_LOG_ERROR, "Empty macroblock in an INTRA picture!\n"); return -1; } mb->type = 1; /* empty macroblocks are always INTER */ mb->cbp = 0; /* all blocks are empty */ mb->q_delta = 0; if (!band->plane && !band->band_num && (ctx->frame_flags & 8)) { mb->q_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table, IVI_VLC_BITS, 1); mb->q_delta = IVI_TOSIGNED(mb->q_delta); } mb->mv_x = mb->mv_y = 0; /* no motion vector coded */ if (band->inherit_mv){ /* motion vector inheritance */ if (mv_scale) { mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale); mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale); } else { mb->mv_x = ref_mb->mv_x; mb->mv_y = ref_mb->mv_y; } } } else { if (band->inherit_mv) { mb->type = ref_mb->type; /* copy mb_type from corresponding reference mb */ } else if (ctx->frame_type == FRAMETYPE_INTRA) { mb->type = 0; /* mb_type is always INTRA for intra-frames */ } else { mb->type = get_bits1(&ctx->gb); } blks_per_mb = band->mb_size != band->blk_size ? 4 : 1; mb->cbp = get_bits(&ctx->gb, blks_per_mb); mb->q_delta = 0; if (band->qdelta_present) { if (band->inherit_qdelta) { if (ref_mb) mb->q_delta = ref_mb->q_delta; } else if (mb->cbp || (!band->plane && !band->band_num && (ctx->frame_flags & 8))) { mb->q_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table, IVI_VLC_BITS, 1); mb->q_delta = IVI_TOSIGNED(mb->q_delta); } } if (!mb->type) { mb->mv_x = mb->mv_y = 0; /* there is no motion vector in intra-macroblocks */ } else { if (band->inherit_mv){ /* motion vector inheritance */ if (mv_scale) { mb->mv_x = ivi_scale_mv(ref_mb->mv_x, mv_scale); mb->mv_y = ivi_scale_mv(ref_mb->mv_y, mv_scale); } else { mb->mv_x = ref_mb->mv_x; mb->mv_y = ref_mb->mv_y; } } else { /* decode motion vector deltas */ mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table, IVI_VLC_BITS, 1); mv_y += IVI_TOSIGNED(mv_delta); mv_delta = get_vlc2(&ctx->gb, ctx->mb_vlc.tab->table, IVI_VLC_BITS, 1); mv_x += IVI_TOSIGNED(mv_delta); mb->mv_x = mv_x; mb->mv_y = mv_y; } } } mb++; if (ref_mb) ref_mb++; mb_offset += band->mb_size; } offs += row_offset; } align_get_bits(&ctx->gb); return 0; }