Qi Hou authored Aug 09, 2021 and GStreamer Marge Bot committed Aug 17, 2021

Some v4l2 drivers don't have the capacity to change framerate. There is
chance to make decoder capture fps to be 0/0 if numerator and denominator
returned by G_PARM ioctl are both 0. It causes critical warning
"passed '0' as denominator for `GstFraction'".

In order to fix this, add protection when set decoder capture fps according
to output fps.

Part-of: <!1048>