From 7d4a1ff344cbf969ac648642a0fd8484fd5b8637 Mon Sep 17 00:00:00 2001 From: Luca Barbato Date: Wed, 2 Mar 2016 18:52:23 -0500 Subject: [PATCH] mpegvideo: Fix undefined negative shifts in ff_init_block_index Found-by: gcc5-ubsan. Signed-off-by: Vittorio Giovara --- libavcodec/mpegvideo.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c index e0787a6790..5974e18b95 100644 --- a/libavcodec/mpegvideo.c +++ b/libavcodec/mpegvideo.c @@ -1754,9 +1754,9 @@ void ff_init_block_index(MpegEncContext *s){ //FIXME maybe rename s->block_index[5]= s->mb_stride*(s->mb_y + s->mb_height + 2) + s->b8_stride*s->mb_height*2 + s->mb_x - 1; //block_index is not used by mpeg2, so it is not affected by chroma_format - s->dest[0] = s->current_picture.f->data[0] + ((s->mb_x - 1) << mb_size); - s->dest[1] = s->current_picture.f->data[1] + ((s->mb_x - 1) << (mb_size - s->chroma_x_shift)); - s->dest[2] = s->current_picture.f->data[2] + ((s->mb_x - 1) << (mb_size - s->chroma_x_shift)); + s->dest[0] = s->current_picture.f->data[0] + (s->mb_x - 1) * (1 << mb_size); + s->dest[1] = s->current_picture.f->data[1] + (s->mb_x - 1) * (1 << (mb_size - s->chroma_x_shift)); + s->dest[2] = s->current_picture.f->data[2] + (s->mb_x - 1) * (1 << (mb_size - s->chroma_x_shift)); if(!(s->pict_type==AV_PICTURE_TYPE_B && s->avctx->draw_horiz_band && s->picture_structure==PICT_FRAME)) {