[FFmpeg-devel] [PATCH] Check for invalid VLC code in zeros_left before writing coefficients.

[Ronald S. Bultje]

From: "Ronald S. Bultje" <rsbultje at gmail.com>

This prevents an invalid write into coeffs[scantable[-1]] if zeros_left
itself was an invalid VLC code (and thus -1).
---
 libavcodec/h264_cavlc.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/libavcodec/h264_cavlc.c b/libavcodec/h264_cavlc.c
index 8702122..fa2bd99 100644
--- a/libavcodec/h264_cavlc.c
+++ b/libavcodec/h264_cavlc.c
@@ -610,17 +610,17 @@ static int decode_residual(H264Context *h, GetBitContext *gb, DCTELEM *block, in
         } \
     }
 
+    if(zeros_left<0){
+        av_log(h->s.avctx, AV_LOG_ERROR, "negative number of zero coeffs at %d %d\n", s->mb_x, s->mb_y);
+        return -1;
+    }
+
     if (h->pixel_shift) {
         STORE_BLOCK(int32_t)
     } else {
         STORE_BLOCK(int16_t)
     }
 
-    if(zeros_left<0){
-        av_log(h->s.avctx, AV_LOG_ERROR, "negative number of zero coeffs at %d %d\n", s->mb_x, s->mb_y);
-        return -1;
-    }
-
     return 0;
 }
 
-- 
1.8.0