(https://scontent.fcgk25-1.fna.fbcdn.net/v/t39.30808-6/325736733_1323903425070902_5846149548285585795_n.jpg?_nc_cat=106&ccb=1-7&_nc_sid=730e14&_nc_eui2=AeE33xUXEm_lLcS7Hn0sPzOdY5LIJ6dreRxjksgnp2t5HAGaDNWsR63eklwjVfZPA3d18RzLhnhT_IZl-e8DUTjo&_nc_ohc=Hf16e_e_uZsAX8xmMYs&tn=VldCbBf3lC8zM1NE&_nc_ht=scontent.fcgk25-1.fna&oh=00_AfDF4j6h_VxQrEN9q8v8ypvXt1comQY5H7ByUzNwcgSgYw&oe=63CC47DB)
(https://scontent.fcgk25-1.fna.fbcdn.net/v/t39.30808-6/326085945_419940586958691_6657523414970722508_n.jpg?_nc_cat=110&ccb=1-7&_nc_sid=730e14&_nc_eui2=AeE2Cv4ND6cf1QvJ82Sx2tfT-CW8oYADxIH4JbyhgAPEgW0B6o_cWIxe40MQe2gyOSaWb9ZIfibit-X0IWlbTkA-&_nc_ohc=KJz8pH9JrCkAX9Y2WBz&_nc_ht=scontent.fcgk25-1.fna&oh=00_AfAtNZWTT3EEo-dYds8Da2QENhQuONGQgigX0BcfXg7dsw&oe=63CE0E30)
Avidemux program cannot decode third-party external codecs such as Ut video RGB VCM or preferably T2.
And in Video Output Ut video (ffmpeg) option, there is no option to vary the chroma subsampling to RGB or 4:4:4 and the conversion results are always chroma subsampling 4:2:0.
The reason for converting to RGB is to avoid video quality degradation due to chroma subsampling. Looks like Avidemux hasn't updated the Ut Video Codec codec and there's no option to convert to RGB/4:4:4 or 4:2:2
The internals of Avidemux use 4:2:0.