liveadder rtp and dynamic filesrc mixing

[Thomas Roos]

hi all,
i want to dynamically add an filesrc/wavparse/queue with it's bin  to
an liveadder, which is running in pipeline and has got an receiving
gstrtpbin stream added already. I think the problem is the play
position when I add the filesrc - shouldn't it be the actual running
time of the pipeline?
I see this event:
GST_EVENT gstevent.c:599:gst_event_new_new_segment_full: creating
newsegment update 0, rate 1.000000, format GST_FORMAT_TIME, start
0:00:00.000000000, stop 0:01:47.624489796, position 0:00:00.000000000
And guess it's already "too late" to mix this stream with the running
gstrtpbin stream?
I tried to set "do-timestamp" on the filesrc - which should set the
timestamps of the file to the actual running time of the bin/pipeline?
I get an strange behaviour - after some time I hear the wave - i guess
it's some clock/running_time wrap around?!

Here's the schematics of the pipeline

udpsrc  (rtp)    ! gstrptbin ! rtppcmdepay ! alawdec ! audioresample !
audioconvert ! queue !
udpsrc (rtcp)   !                 udpsink (rtcp)


  ! liveadder ! queue ! alsasink
                    filesrc ! wavparse ! volume ! capsfilter !
audioresample ! audioconvert ! queue !

Thank you for any help/idea/feedback
cheers Thomas