From 50b77e364f0a8c94de523e1d5afcd2be0a9a0384 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Fri, 26 Jun 2015 04:26:05 +0200
Subject: [PATCH] avcodec/jpeg2000dec: iterate over positions with the special
cases from jpeg2000
The order in j2k is not the simple and logic one
Fixes Ticket4670
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/jpeg2000dec.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 7e1fc5e7757..4ba8bcf9d6a 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -1163,9 +1163,8 @@ static int jpeg2000_decode_packets(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile
step_x = 1<<step_x;
step_y = 1<<step_y;
- //FIXME we could iterate over less than the whole image
- for (y = 0; y < s->height; y += step_y) {
- for (x = 0; x < s->width; x += step_x) {
+ for (y = tile->coord[1][0]; y < tile->coord[1][1]; y = (y/step_y + 1)*step_y) {
+ for (x = tile->coord[0][0]; x < tile->coord[0][1]; x = (x/step_x + 1)*step_x) {
for (compno = 0; compno < s->ncomponents; compno++) {
Jpeg2000Component *comp = tile->comp + compno;
Jpeg2000CodingStyle *codsty = tile->codsty + compno;
@@ -1178,10 +1177,10 @@ static int jpeg2000_decode_packets(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile
uint8_t reducedresno = codsty->nreslevels - 1 -reslevelno; // ==> N_L - r
Jpeg2000ResLevel *rlevel = comp->reslevel + reslevelno;
- if (yc % (1 << (rlevel->log2_prec_height + reducedresno)))
+ if (yc % (1 << (rlevel->log2_prec_height + reducedresno)) && y != tile->coord[1][0]) //FIXME this is a subset of the check
continue;
- if (xc % (1 << (rlevel->log2_prec_width + reducedresno)))
+ if (xc % (1 << (rlevel->log2_prec_width + reducedresno)) && x != tile->coord[0][0]) //FIXME this is a subset of the check
continue;
// check if a precinct exists
--
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