From 49255370044cf4a58c81a88cb8206aee62086346 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Fri, 21 Apr 2017 21:44:28 +0200 Subject: [PATCH] avcodec/utvideodec: fix gradient prediction when stride does not match width Fixes #6340. Signed-off-by: Paul B Mahol --- libavcodec/utvideodec.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/libavcodec/utvideodec.c b/libavcodec/utvideodec.c index 25e32a6055..7979618f42 100644 --- a/libavcodec/utvideodec.c +++ b/libavcodec/utvideodec.c @@ -676,7 +676,11 @@ static void restore_gradient_planar_il(UtvideoContext *c, uint8_t *src, ptrdiff_ C = bsrc[i - 1]; bsrc[i] = (A - B + C + bsrc[i]) & 0xFF; } - for (i = 0; i < width; i++) { + A = bsrc[-stride]; + B = bsrc[-(1 + stride + stride - width)]; + C = bsrc[width - 1]; + bsrc[stride] = (A - B + C + bsrc[stride]) & 0xFF; + for (i = 1; i < width; i++) { A = bsrc[i - stride]; B = bsrc[i - (1 + stride)]; C = bsrc[i - 1 + stride]; @@ -774,7 +778,11 @@ static void restore_gradient_packed_il(uint8_t *src, int step, ptrdiff_t stride, C = bsrc[i - step]; bsrc[i] = (A - B + C + bsrc[i]) & 0xFF; } - for (i = 0; i < width * step; i += step) { + A = bsrc[-stride]; + B = bsrc[-(step + stride + stride - width * step)]; + C = bsrc[width * step - step]; + bsrc[stride] = (A - B + C + bsrc[stride]) & 0xFF; + for (i = step; i < width * step; i += step) { A = bsrc[i - stride]; B = bsrc[i - (step + stride)]; C = bsrc[i - step + stride];