MKVToolnix - changing Aspect Ratio

[pooksahib]

Am I correct in thinking that, when using toolnix to change the Aspect Ratio, you have to create a new file? As far as I can see, Header Editor can change a file in many ways but Aspect Ratio doesn't seem to be one of them. Thank you.

[sneaker]

You can do it with the Header Editor. It's "Video display width"+"Video display height" of the video track (default unit is in number of pixels).

[pooksahib]

Niiice... At first, I thought that '4' and '3' would be inappropriate values for those boxes but it works. Thanks, sneaker.

[sneaker]

They are inappropriate unless you also set "Video display unit" to "3"(=aspect ratio). By default "Video display width" and "Video display height" are supposed to be in pixels.

https://www.matroska.org/technical/specs/index.html#DisplayUnit

[pooksahib]

OK, thanks again, you're a great help.