Using gstreamer to merge the streams into one?

Anyone ever used gstreamer to do this with Licode?
For efficiency in broadcasting 2-to-many situations, I’m looking to do this.

I’d also be interested in simply merging the recordings.

I’ve programmed my app to record both streams at the exact same time and
stop them at the exact same time so I basically just need to merge them
together in an attractive manner. Not necessarily just using ffmpeg to
tile it… but to make it look presentable.

For instance, on mobile, if a user rotates the device the orientation of
the video may rotate causing a switch in the resolution in the middle of
the stream. I’d need to account for this, that’s why I figure gstreamer
would be the best bet.

No idea how to go about it though…