[FFmpeg-devel] [PATCH] make av_set_pts_info more robust

[Reimar Döffinger]

Hello,
I don't have a sample file for the issue, but the AVI demuxer and probably
more pass on user data unchecked to av_set_pts_info.
So I propose to change it in a way that will avoid a division by 0.
Not sure if that's the best idea, but it seemed like a good idea (I
originally thought this was the cause of a crash I am investigating).
Index: libavformat/utils.c
===================================================================
--- libavformat/utils.c	(revision 19317)
+++ libavformat/utils.c	(working copy)
@@ -3308,8 +3308,10 @@
 {
     unsigned int gcd= av_gcd(pts_num, pts_den);
     s->pts_wrap_bits = pts_wrap_bits;
+    if (pts_num > 0 && pts_den > 0) {
     s->time_base.num = pts_num/gcd;
     s->time_base.den = pts_den/gcd;
+    }
 
     if(gcd>1)
         av_log(NULL, AV_LOG_DEBUG, "st:%d removing common factor %d from timebase\n", s->index, gcd);