[FFmpeg-user] How to pass vp8/vp9 frames from another application to ffmpeg pipeline?

[sonntex]

My application gets vp8/vp9 frames from network and then I want to put
these frames further to ffmpeg pipeline. Couldn't find a proper way to do
that. For instance, in the case of h264 I could write h264 byte stream to a
pipe and then read it using ffmpeg. Nothing similar for v8/v9 except ivf
which requires at least libvpx on my side.

The main goal is to save v8/v9 stream to mp4/webm/ivf containers based on
the options user set.