[FFmpeg-cvslog] avcodec/h264_cavlc: Set valid qscale value in ff_h264_decode_mb_cavlc()

[Xiaohan Wang]

ffmpeg | branch: release/2.8 | Xiaohan Wang <xhwang at chromium.org> | Sat Feb  3 01:43:35 2018 -0800| [07e46226ae50ce0e4754b5cc11fafaffb1d4116a] | committer: Michael Niedermayer

avcodec/h264_cavlc: Set valid qscale value in ff_h264_decode_mb_cavlc()

When ff_h264_decode_mb_cavlc() failed due to wrong sl->qscale values,
e.g. dquant out of range, set the qscale to be a valid value before
returning -1 and exiting the function. The qscale value can be used
later e.g. in loop filter.

BUG=806122

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 71f39de2a57efc8db1d607b09c162c3b806cd45d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=07e46226ae50ce0e4754b5cc11fafaffb1d4116a
---

 libavcodec/h264_cavlc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavcodec/h264_cavlc.c b/libavcodec/h264_cavlc.c
index 3fa5b2e197..97ec6fd4ae 100644
--- a/libavcodec/h264_cavlc.c
+++ b/libavcodec/h264_cavlc.c
@@ -1113,6 +1113,7 @@ decode_intra_mb:
             else                sl->qscale -= max_qp+1;
             if (((unsigned)sl->qscale) > max_qp){
                 av_log(h->avctx, AV_LOG_ERROR, "dquant out of range (%d) at %d %d\n", dquant, sl->mb_x, sl->mb_y);
+                sl->qscale = max_qp;
                 return -1;
             }
         }