How to use rtpvorbisdepay with vorbisparse/matroskamux?

[Peter Randeu]

Hello!

Using gstreamer-1.0, I am trying to receive a Vorbis encoded, RTP payed 
audio stream, pass it to a Matroska muxer and write it to a file. The 
gst-launch pipe I am using for testing looks like this:

gst-launch-1.0 audiotestsrc is-live=true ! vorbisenc ! rtpvorbispay ! 
rtpvorbisdepay ! matroskamux ! fakesink silent=false -v

The problem is that the fakesink produces no output.

Looking at the debug output of gst-launch I have noticed that the caps 
created by rtpvorbisdepay only contain "audio/x-vorbis", other 
properties like "rate" or "streamheader" are not present. Using a 
vorbisparse element does not help, nor does setting the caps explicitly 
between rtpvorbisdepay and matroskamux or rtpvorbispay and rtpvorbisdepay:

gst-launch-1.0 audiotestsrc is-live=true ! vorbisenc ! rtpvorbispay ! 
$RTPCAPS ! rtpvorbisdepay ! $VORBISCAPS ! vorbisparse ! matroskamux ! 
fakesink silent=false -v

where $VORBISCAPS are the caps of the vorbisenc src-pad and $RTPCAPS are 
the caps of the rtpvorbispay src-pad.

Do I miss something to get the above pipeline working?

Peter