jpeg2000: Calculate code-block coord in ff_jpeg2000_init_component()

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
Signed-off-by: Nicolas Bertrand <nicoinattendu@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/jpeg2000.c

@@ -443,6 +443,20 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
                     /* 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;

libavcodec/jpeg2000dec.c

@@ -1119,17 +1119,8 @@ static int jpeg2000_decode_tile(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
                                     cblk->coord[1][1] - cblk->coord[1][0],
                                     bandpos);
 
-                        /* Manage band offsets */
                         x = cblk->coord[0][0];
                         y = cblk->coord[1][0];
-                        if ((reslevelno > 0) && ((bandno + 1) & 1)) {
-                            Jpeg2000ResLevel *pres = comp->reslevel + (reslevelno - 1);
-                            x += pres->coord[0][1] - pres->coord[0][0];
-                        }
-                        if ((reslevelno > 0) && ((bandno + 1) & 2)) {
-                            Jpeg2000ResLevel *pres = comp->reslevel + (reslevelno - 1);
-                            y += pres->coord[1][1] - pres->coord[1][0];
-                        }
 
                         if (s->avctx->flags & CODEC_FLAG_BITEXACT)
                             dequantization_int(x, y, cblk, comp, &t1, band);