[FFmpeg-cvslog] avdevice/v4l2: only use frame period from v4l2 if valid

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sun Feb  2 00:10:43 2014 +0100| [4aa4533ee8b51a1e6bdc4fbffaf90aa2b14e2c9f] | committer: Michael Niedermayer

avdevice/v4l2: only use frame period from v4l2 if valid

There is evidence that some drivers do not set a valid value

See: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=718805
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4aa4533ee8b51a1e6bdc4fbffaf90aa2b14e2c9f
---

 libavdevice/v4l2.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c
index 1ab6f1c..b4f65d3 100644
--- a/libavdevice/v4l2.c
+++ b/libavdevice/v4l2.c
@@ -742,9 +742,12 @@ static int v4l2_set_parameters(AVFormatContext *s1)
                    "The driver does not allow to change time per frame\n");
         }
     }
-    s1->streams[0]->avg_frame_rate.num = tpf->denominator;
-    s1->streams[0]->avg_frame_rate.den = tpf->numerator;
-    s1->streams[0]->r_frame_rate = s1->streams[0]->avg_frame_rate;
+    if (tpf->denominator > 0 && tpf->numerator > 0) {
+        s1->streams[0]->avg_frame_rate.num = tpf->denominator;
+        s1->streams[0]->avg_frame_rate.den = tpf->numerator;
+        s1->streams[0]->r_frame_rate = s1->streams[0]->avg_frame_rate;
+    } else
+        av_log(s1, AV_LOG_WARNING, "Time per frame unknown\n");
 
     return 0;
 }