Muxing udpsrc with videotestsrc?

Hello, I have an Audio only multicast stream that I am trying to combine a dummy video screen over. I’m trying to pass this into kvssink so I cannot only stream the audio. The video needs to be in H264 and the audio in AAC as I am trying to pass this to AWS using the kvssink plugin.

Here is the stream properties (via gst-discoverer-1.0) if it helps!

Properties:
  Duration: 99:99:99.999999999
  Seekable: no
  Live: yes
  container #0: application/rtp
    unknown #2: application/x-rtp
      container #-1: MPEG-2 Transport Stream
        audio #1: MPEG-4 AAC

Here is the most recent attempt at a pipeline that errored as Mux could not link to Kvssink

gst-launch-1.0 udpsrc address=239.0.0.7 port=5004 ! audioconvert ! avenc_aac ! aacparse ! queue ! mux. videotestsrc pattern=black is-live=true ! x264enc ! queue ! mp4mux name=mux ! kvssink

Hi, is the error linking to kvssink caused by caps not matching?
Could you share your error message?

Usually linking will fail because the input format is not supported. You might need a conversion element before kvssink.

Hello! I ended up just brute forcing my way around it by not trying to mux it with an empty data source and doing my own data conversion on my own servers rather than using KVS’s display url’s.