Fix files with fps between 0.5 and 0.1.

Fixes issue749

Originally committed as revision 16123 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffplay.c

@@ -1024,7 +1024,7 @@ static void video_refresh_timer(void *opaque)
 
             /* compute nominal delay */
             delay = vp->pts - is->frame_last_pts;
-            if (delay <= 0 || delay >= 2.0) {
+            if (delay <= 0 || delay >= 10.0) {
                 /* if incorrect delay, use previous one */
                 delay = is->frame_last_delay;
             }