tdf#125821 don't crash on missing gstreamer plugins

If GStreamer can't auto-detect an audio sink via "autoaudiosink",
it'll return a nullptr. If the volume plugin is missing, then this
currently also results in a crash.

So check the gst_element_factory_make results before using the
objects and change some wrong mpPlaybin checks to the right
mpVolumeControl ones.

This works for me without any audio and volume plugins. Since we
are linked against libgstaudio, I assume the bin is always there.

Change-Id: Ide526363d810ea48d0a62539c0a435553783e34a
Reviewed-on: https://gerrit.libreoffice.org/73848
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

0 files changed, 0 insertions, 0 deletions