SEGA CD - Encode in SGA ?

Hi all,
I would like to know if there is a software capable of re-encoding in SGA.
I have seen a lot of tools including SGA Tools which allows to read and encode in AVI, a command under ffmpeg allowing to demux SGA files but nothing which can encode in SGA.
The goal is simply to be able to replace the audio and translate this audio.
If anyone has a lead.. and above all thank you in advance for the advice.
Well, I don't do as much with the Genesis/SCD, but you could start with the SCDTools:

You might also go to the thread on the recent video competition and video the users who submitted videos for the Genesis and PM them about how they did their videos.