static int init_prec(Jpeg2000Band *band, Jpeg2000ResLevel *reslevel, Jpeg2000Component *comp, int precno, int bandno, int reslevelno, int log2_band_prec_width, int log2_band_prec_height) { Jpeg2000Prec *prec = band->prec + precno; int nb_codeblocks, cblkno; prec->decoded_layers = 0; /* TODO: Explain formula for JPEG200 DCINEMA. */ /* TODO: Verify with previous count of codeblocks per band */ /* Compute P_x0 */ prec->coord[0][0] = ((band->coord[0][0] >> log2_band_prec_width) + precno % reslevel->num_precincts_x) * (1 << log2_band_prec_width); /* Compute P_y0 */ prec->coord[1][0] = ((band->coord[1][0] >> log2_band_prec_height) + precno / reslevel->num_precincts_x) * (1 << log2_band_prec_height); /* Compute P_x1 */ prec->coord[0][1] = prec->coord[0][0] + (1 << log2_band_prec_width); prec->coord[0][0] = FFMAX(prec->coord[0][0], band->coord[0][0]); prec->coord[0][1] = FFMIN(prec->coord[0][1], band->coord[0][1]); /* Compute P_y1 */ prec->coord[1][1] = prec->coord[1][0] + (1 << log2_band_prec_height); prec->coord[1][0] = FFMAX(prec->coord[1][0], band->coord[1][0]); prec->coord[1][1] = FFMIN(prec->coord[1][1], band->coord[1][1]); prec->nb_codeblocks_width = ff_jpeg2000_ceildivpow2(prec->coord[0][1], band->log2_cblk_width) - (prec->coord[0][0] >> band->log2_cblk_width); prec->nb_codeblocks_height = ff_jpeg2000_ceildivpow2(prec->coord[1][1], band->log2_cblk_height) - (prec->coord[1][0] >> band->log2_cblk_height); /* Tag trees initialization */ prec->cblkincl = ff_jpeg2000_tag_tree_init(prec->nb_codeblocks_width, prec->nb_codeblocks_height); if (!prec->cblkincl) return AVERROR(ENOMEM); prec->zerobits = ff_jpeg2000_tag_tree_init(prec->nb_codeblocks_width, prec->nb_codeblocks_height); if (!prec->zerobits) return AVERROR(ENOMEM); if (prec->nb_codeblocks_width * (uint64_t)prec->nb_codeblocks_height > INT_MAX) { prec->cblk = NULL; return AVERROR(ENOMEM); } nb_codeblocks = prec->nb_codeblocks_width * prec->nb_codeblocks_height; prec->cblk = av_mallocz_array(nb_codeblocks, sizeof(*prec->cblk)); if (!prec->cblk) return AVERROR(ENOMEM); for (cblkno = 0; cblkno < nb_codeblocks; cblkno++) { Jpeg2000Cblk *cblk = prec->cblk + cblkno; int Cx0, Cy0; /* Compute coordinates of codeblocks */ /* Compute Cx0*/ Cx0 = ((prec->coord[0][0]) >> band->log2_cblk_width) << band->log2_cblk_width; Cx0 = Cx0 + ((cblkno % prec->nb_codeblocks_width) << band->log2_cblk_width); cblk->coord[0][0] = FFMAX(Cx0, prec->coord[0][0]); /* Compute Cy0*/ Cy0 = ((prec->coord[1][0]) >> band->log2_cblk_height) << band->log2_cblk_height; Cy0 = Cy0 + ((cblkno / prec->nb_codeblocks_width) << band->log2_cblk_height); cblk->coord[1][0] = FFMAX(Cy0, prec->coord[1][0]); /* Compute Cx1 */ cblk->coord[0][1] = FFMIN(Cx0 + (1 << band->log2_cblk_width), prec->coord[0][1]); /* Compute Cy1 */ cblk->coord[1][1] = FFMIN(Cy0 + (1 << band->log2_cblk_height), prec->coord[1][1]); /* Update code-blocks coordinates according sub-band position */ if ((bandno + !!reslevelno) & 1) { cblk->coord[0][0] += comp->reslevel[reslevelno-1].coord[0][1] - comp->reslevel[reslevelno-1].coord[0][0]; cblk->coord[0][1] += comp->reslevel[reslevelno-1].coord[0][1] - comp->reslevel[reslevelno-1].coord[0][0]; } if ((bandno + !!reslevelno) & 2) { cblk->coord[1][0] += comp->reslevel[reslevelno-1].coord[1][1] - comp->reslevel[reslevelno-1].coord[1][0]; cblk->coord[1][1] += comp->reslevel[reslevelno-1].coord[1][1] - comp->reslevel[reslevelno-1].coord[1][0]; } cblk->zero = 0; cblk->lblock = 3; cblk->length = 0; memset(cblk->lengthinc, 0, sizeof(cblk->lengthinc)); cblk->npasses = 0; } return 0; }