On some DVD rips of tv shows you get the slashed interlaced lines, I see no way on direct playback to deinterlace the material, I don’t envode just rip to mkv
AFAIK, you can’t deinterlace without re-encoding video.
Would need to be either done on the fly transcoded (like VLC can do) or when archiving.
This is correct. You must re-encode to fix this. Handbrake for example will usually choose the correct deinterlacing method, but just do one episode first and make sure the result file is good. Look carefully for moments of bad interlacing artifacts especially around small rapid movement (like eye blinks or hand movements), that means Handbrake didn’t deinterlace properly. Use MediaInfo to examine one of the rip files to find the original interlace method, and try again (usually this is a Top Field First vs Bottom Field First issue).
Most encoders can do the job if they support Aavisynth. Just load the YADIF Deinterlacing filter.
