h264: reset first_field if frame_start() fails for missing refs

In this case we may not have a current frame, while first_field being
set implies we do.

Fixes invalid reads.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
This commit is contained in:
Anton Khirnov 2013-11-28 10:54:35 +01:00
parent 210881110d
commit d1b3fabe69

View File

@ -3619,8 +3619,11 @@ static int decode_slice_header(H264Context *h, H264Context *h0)
av_log(h->avctx, AV_LOG_DEBUG, "Frame num gap %d %d\n",
h->frame_num, h->prev_frame_num);
ret = h264_frame_start(h);
if (ret < 0)
if (ret < 0) {
h0->first_field = 0;
return ret;
}
h->prev_frame_num++;
h->prev_frame_num %= 1 << h->sps.log2_max_frame_num;
h->cur_pic_ptr->frame_num = h->prev_frame_num;