From 9953fc9a2372cb09ec8e3d9395611f4285916d46 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Wed, 26 Jan 2022 00:22:50 +0100 Subject: [PATCH] avcodec/mpegvideo: Fix off-by-one error when decoding >8 bit MPEG-4 Fixes visual corruptions on two macroblocks from two frames from https://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket4447/A003C003_SR_422_23.98p.mxf Reviewed-by: Kieran Kunhya Signed-off-by: Andreas Rheinhardt --- libavcodec/mpegvideo.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c index e9f2fb212a..47603c2991 100644 --- a/libavcodec/mpegvideo.c +++ b/libavcodec/mpegvideo.c @@ -1648,8 +1648,8 @@ void mpv_reconstruct_mb_internal(MpegEncContext *s, int16_t block[12][64], int vsub = i ? s->chroma_y_shift : 0; int hsub = i ? s->chroma_x_shift : 0; dest_pcm[i] += (linesize[i] / 2) * ((16 >> vsub) - 1); - for(h = (16 >> vsub)-1; h >= 1; h--){ - for(w = (16 >> hsub)-1; w >= 1; w--) + for (h = (16 >> vsub) - 1; h >= 0; h--) { + for (w = (16 >> hsub) - 1; w >= 0; w--) dest_pcm[i][w] = (*s->dpcm_macroblock)[i][idx++]; dest_pcm[i] -= linesize[i] / 2; }