First the AVI MPEG-2 does not recode, actually if uses a -vcodec copy so it essentially copies the video stream but recodes the audio stream to keep it in sync.
However as I'm writing this I'm creating a new AVI MPEG2 profile for the next 2.3.12 beta release tomorrow which will use the copy encoder
Regarding the WTV unprocessed: this is the latest profile as per the BETA release.
Description=Creates WTV (MPEG-2) files by copying the video directly. It does not resize, remove black bars, deinterlace your videos or select audio language. Use this if you have high quality HD recordings which don't need processing.
ffmpeg-video=-ss 3 -vcodec mpeg2video -qscale 2 -map 0:a -map 0:v
ffmpeg-audio=-acodec ac3 -ab 192k
ffmpeg-audioac3=-acodec ac3 -ab 384K
if you notice the order of encoders are copy followed by ffmpeg. ie. if copy fails then it falls back to ffmpeg
the Copy encoder is a special encoder with no audio/video parameters so essentially it just moves the input file into a WTV format after removing commercials. Please note that this profile only works correctly in the latest BETA release due to a bug.
the FFMPEG is backup, which is where the AC3 codec comes into the picture. This helps maintain audio video sync but if you'd like you can replace that with
-acodec copy to just copy over the original stream without recoding it.