# Demux AVI containing pre-bayer data
ffmpeg -i drop1.avi -vcodec copy -an -f rawvideo drop1.rawv

# demuxed raw to mp4
ffmpeg -r 25 -f rawvideo -s 1920x1081 -pix_fmt bayer_grbg8 -i drop1.rawv -filter:v "crop=1920:1080" -preset veryfast out.mp4

# But this does not work
ffmpeg -r 25 -f rawvideo -s 1920x1081 -pix_fmt bayer_grbg8 -i drop1.avi -filter:v "crop=1920:1080" -an -c:v libx264 -preset veryfast drop1_conv.mp4