From: Gautam Ramakrishnan <gautamr...@gmail.com>
Reduce image size of the image if all components have
a non zero sample separation. This is to replicate the
output of opj_decompress.
---
libavcodec/jpeg2000dec.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index ab36009a2d..05e85f4317 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -269,6 +269,8 @@ static int get_siz(Jpeg2000DecoderContext *s)
const enum AVPixelFormat *possible_fmts = NULL;
int possible_fmts_nb = 0;
int ret;
+ int o_dimx, o_dimy; //original image dimensions.
+ int dimx, dimy;
if (bytestream2_get_bytes_left(&s->g) < 36) {
av_log(s->avctx, AV_LOG_ERROR, "Insufficient space for SIZ\n");
@@ -371,11 +373,18 @@ static int get_siz(Jpeg2000DecoderContext *s)
}
/* compute image size with reduction factor */
- ret = ff_set_dimensions(s->avctx,
- ff_jpeg2000_ceildivpow2(s->width - s->image_offset_x,
- s->reduction_factor),
- ff_jpeg2000_ceildivpow2(s->height - s->image_offset_y,
- s->reduction_factor));
+ o_dimx = ff_jpeg2000_ceildivpow2(s->width - s->image_offset_x,
+ s->reduction_factor);
+ o_dimy = ff_jpeg2000_ceildivpow2(s->height - s->image_offset_y,
+ s->reduction_factor);
+ dimx = ff_jpeg2000_ceildiv(o_dimx, s->cdx[0]);
+ dimy = ff_jpeg2000_ceildiv(o_dimy, s->cdy[0]);
+ for (i = 1; i < s->ncomponents; i++) {
+ dimx = FFMAX(dimx, ff_jpeg2000_ceildiv(o_dimx, s->cdx[i]));
+ dimy = FFMAX(dimy, ff_jpeg2000_ceildiv(o_dimy, s->cdy[i]));
+ }
+
+ ret = ff_set_dimensions(s->avctx, dimx, dimy);
if (ret < 0)
return ret;
--
2.17.1
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