why is video quality worse on vlc than windows media player

More often than not once the video has started playing, if I touch the player with the mouse, it goes away and I get a crash dialog on next start. Many thanks for all the help from all who responded. I enabled the De-Interlacing mode on VLC and problem all solved and now looks every bit the same as the original DVD did under DVD PLayer. Is this expected/normal? Is there some config I have wrong? I'm quite concerned as I'm mid way through converting a large collection of DVD's to MKV and if this quality loss is to be expected then I'd have to go back to the original VIDEO_TS format. I thought it might be related to the player but I've tried multiple players all with the same result. Given I thought MKV was basically just a container around the original with no loss of quality, I'm at a loss as to explain why. There is no equivalent pixelation of quality loss around moving objects. I thought it must be bad quality DVD but when I watch the DVD using DVD Player on the mac the quality is fine. They dissapear when the object stops moving. However when I play it in either Plex or VLC there is a lot of pixelation and horizontal lines appearing around any object that is moving quickly on the screen.

I extracted each episode as a separate MKV. I have just converted a children's TV show from DVD (one of the In The Night Garden Series.). I am using MakeMKV on a mac and Plex/VLC to view my movies. The reason I've switched to MKV is to keep full quality while gaining the benefits that the media players like Plex offer. Prior to this I always just ripped my DVD as VIDEO_TS rips so as to keep the full original. I have searched the forums for the answer to this so my apologies if it has been answered before.

Why is video quality worse on vlc than windows media player