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h.264libavcodec

How is it possible to have different aspect ratio than physical resolution?

I have this movie that is in 4:3 ratio. The properties clearly say 1920x1440, however, what's puzzling me is the Video codec below. The actual played video indeed has dimensions of 1920x1440 as seen in the screenshot.

H.264/AVC 1920x1080 (4:3)

What does it mean and how is that possible?
What is the actual resolution of the media file?

MPC:BE

Solution

  • There are several terms defining aspect ratios in a video stream like Pixel Aspect Ratio (PAR), Display Aspect Ratio (DAR), Storage Aspect Ratio (SAR).

    And yes, video might encode non-square pixels, in which case you may see disparity as in your case, when physical resolution of the video has 1920x1080 dimensions (16:9 aspect ratio), but displayed at different proportions (4:3 in your case). I don't know why player (which one?) shows 1920x1440 - I guess it is an internal implementation detail of a particular video player stretching an input video into a larger resolution to show it with designed proportions; another video player would do this in a different way.

    Non-square pixels were very common in DVD times due to limitations of hardware of that time. Nowadays, such video streams occur very rarely.