How to track down assertion failures

[Tim-Philipp Müller]

On Fri, 2013-03-01 at 09:12 -0700, Gary Thomas wrote:
> I'm using 0.10 to display an RTSP video stream with a pipeline that looks like this:
>    rtspsrc name=src \
>      src. ! tee name=v-t \
>        v-t. ! queue ! rtph264depay ! h264parse ! ffdec_h264 ! videoscale ! video/x-raw-yuv,width=240,height=120 ! ffmpegcolorspace ! ximagesink  \
>      src. ! tee name=a-t \
>        a-t. ! queue ! rtpmpadepay ! mpegaudioparse ! fakesink
> 
> Once it gets going, I get a slew of these errors:n
>    GStreamer-CRITICAL **: _gst_util_uint64_scale_int: assertion `num >= 0' failed
> 
> How can I track down which of the NNNN uses of that function is
> throwing this assertion?

You can run

 $ G_DEBUG=fatal_warnings gdb --args /usr/bin/gst-launch-0.10 xyz...

then it will abort at the warning and you can get a stack trace and
print the elements.

Cheers
 -Tim