[FFmpeg-cvslog] diracdec: check lowdelay bytes.

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Mon Apr 16 18:22:22 2012 +0200| [efe1ba7201b3bb609d3a41091e15e875137f3f32] | committer: Michael Niedermayer

diracdec: check lowdelay bytes.

Fixes division by zero

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=efe1ba7201b3bb609d3a41091e15e875137f3f32
---

 libavcodec/diracdec.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index 5c4ed88..b5395db 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -980,6 +980,11 @@ static int dirac_unpack_idwt_params(DiracContext *s)
         s->lowdelay.bytes.num = svq3_get_ue_golomb(gb);
         s->lowdelay.bytes.den = svq3_get_ue_golomb(gb);
 
+        if (s->lowdelay.bytes.den <= 0) {
+            av_log(s->avctx,AV_LOG_ERROR,"Invalid lowdelay.bytes.den\n");
+            return AVERROR_INVALIDDATA;
+        }
+
         /* [DIRAC_STD] 11.3.5 Quantisation matrices (low-delay syntax). quant_matrix() */
         if (get_bits1(gb)) {
             av_log(s->avctx,AV_LOG_DEBUG,"Low Delay: Has Custom Quantization Matrix!\n");