When decoding a bitstream with weighted-bipred enabled,
the results on ARM and x86 platforms may differ.
The reason for the inconsistency is that the value of
STRIDE_ALIGN differs between platforms. And STRIDE_ALIGN
is set to the buffer stride of temporary buffers for U
and V components in mc_part_weighted.
If the buffer stride is 32 or 64 (as on x86 platforms),
the U and V pixels can be interleaved row by row without
overlapping, resulting in correct output.
However, on ARM platforms where the stride is 16,
the V component will overwrite part of the U component's pixels,
leading to incorrect predicted pixels.
Fixes: ticket 11357
Signed-off-by: Bin Peng <peng...@visionular.com>
---
libavcodec/utils.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 2dbd677920..d280e1c324 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -147,6 +147,7 @@ void avcodec_align_dimensions2(AVCodecContext *s, int
*width, int *height,
int i;
int w_align = 1;
int h_align = 1;
+ int stride_align = STRIDE_ALIGN;
AVPixFmtDescriptor const *desc = av_pix_fmt_desc_get(s->pix_fmt);
if (desc) {
@@ -342,13 +343,14 @@ void avcodec_align_dimensions2(AVCodecContext *s, int
*width, int *height,
// increasing witdth ensure that the temporary area is large enough,
// the next rounded up width is 32
*width = FFMAX(*width, 32);
+ stride_align = FFMAX(stride_align, 32);
}
if (s->codec_id == AV_CODEC_ID_SVQ3) {
*width = FFMAX(*width, 32);
}
for (i = 0; i < 4; i++)
- linesize_align[i] = STRIDE_ALIGN;
+ linesize_align[i] = stride_align;
}
void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height)
--
2.25.1
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