Rtpmux, when video sink not feed all the muxed stream (output) is blocked


I multiplex two sources , audio and video from network camera, using rtpmux.
When camera lags, due to network noises, the final AV stream is stopped till camera suceed sending new data. I would like to avoid it.
Is it possible to fill video part with dummy content, allowing muxed stream to continue sending audio data, at least…?
Thanks for your help.
Best regads,


NOTE: using mp4mux this already works…the produced mp4 just cuts missing video part only