You're "empty" will have to be a correctly encoded H.264 block of solid colour.
If you can encode this at the correct resolution (or precreate this), then you
can feed it to the file sinks before any video data (maybe with a wrapper
subclass).
Most of this is beyond the scope of liveMedia itself
> I am using OpenRTSP and i am looking for a way to add Xms of empty frames at
> the beginning of my vidéo
“openRTSP” simply records the (encoded) video data that it sees in the incoming
stream. It’s not intended to perform any processing of this video data. Nor
does the “LIVE555 Streaming Me