properly link quadmixer with a requested pad
docu & logging
link videomixer via requested ghostpad
show debug output from gst element
reduce preview size
test-av-sources and audio-stream layout
try the newer compositor
i was just do dumb to see my hierachy issue
add example of the timestamoing-issue that occurs when multiple outputs are active
add a 2nd test-video src
coming closer to a real failsafe shmsrc
this time I have itgit diff git diff git diff  I think..