I got a DVD pretty recently and decided to rip the files via MakeMKV to put the movie on Plex. Thing is… the aspect ratio is wrong.
The movie is indeed in 4:3 (720x576), but the video is a bit stretched. I assume this is a PAL related thing.
So I went to MKVToolNix and tried to do the 4:3 properties fix. It didn’t work, multiplex file was the same. Then I tried to make the video 960x720… It didn’t work either.
Then I decided to make it 16:9 just to see what it was going to do, then it worked (as far as watching it on VLC), but I assume this is not the correct way to do this (the video now has black bars).
720x576 is not 4:3, it’s 5:4. It’s the standard frame size for storage & transmission of digitized PAL video. NTSC uses 720x480, which is 3:2. There’s an expectation that the player will read Display Aspect Ratio metadata (e.g. 4:3 or 16:9) from the file and then squish or stretch the image as necessary when rendering it to the output device.
The correct aspect ratio for output is stored at the container level (the MKV file created by MakeMKV) and within the MPEG-2 video bitstream itself. What a particular player does when this info is missing or conflicting is uncertain. MKVToolNix only lets you edit the container-level data; you need to use FFmpeg to fix the aspect ratio in the video bitstream.
But what exactly needs to be done, and why it’s going wrong in the first place, is a bit of a mystery, because normally it should all be correct (DVD only allows for certain combinations) and what you get from MakeMKV should work fine in VLC. I mean, MakeMKV is just remixing the DVD’s video & audio streams into an MKV container, not changing DAR metadata. I’d need to experiment with the files to figure out the problem.
I suspect it may be a 4:3 picture which, instead of being encoded on the DVD such that it fills up the 5:4 storage frame, was instead converted to pillarboxed 16:9 first, then squished down to 5:4 for storage, black bars and all…a waste of precious horizontal space, absolutely unnecessary unless some other part of the film fills up the whole 16:9 screen (for smooth playback they have to keep the aspect ratio the same for the entire movie). In this case, the correct DAR is indeed 16:9 and the film literally includes the black bars.
