How can the AR be 0.83:1?

[Djard]

I have a video clip that MediaInfo reports as having a resolution of 480x576, which aspect ratio would be 0.83:1. Media Player Classic plays the clip properly, displaying it as 1.33:1 (there is a black border on the right side of the picture, taking up about 4% of the screen).

Recoding the clip at 576x480 (1.20:1) causes faces in the video to appear skinny. The black border is preserved in the picture. Recoding at 576x432 (1.33:1) renders the faces OK, but the picture is displayed with padding above and below in Media Player Classic. Can someone throw some light on what I'm experiencing?

[Baldrick]

A video can be stored in any Storage Aspect Ratio like 0.83:1 but the Display Aspect Ratio is 4:3. So it will look okey in players that read the display aspect ratio correctly.

See http://en.wikipedia.org/wiki/Pixel_aspect_ratio and http://en.wikipedia.org/wiki/Aspect_ratio_(image)

How do you reconvert it to 4:3(1.333)?

[Cornucopia]

Yes. EVERY video has 3 aspect ratios: Display aspect ratio (the shape of the dislay container it's supposed to fit in), Storage AR (not really a shape at all, just a ratio of stored horizontal & vertical pixel resolutions), and Pixel AR (the shape of the Pixels that make up the image).

Way too many people put too much stock in Storage AR, but there's no such thing. It's really just the result of the other 2, which are the important ones (remember SAR * PAR = DAR or better yet, Hrez / Vrez * PAR = DAR, and that'll always help you get to where you need to go).

Scott

[AlanHK]

Media info apps, like G-Spot, should give you the SAR, PAR, and DAR.

[Djard]

Thanks for the valuable info.

Baldrick, I recoded the clip with AVS Video Converter, setting the resolution of the "Output frame size" to 480x360 and selecting 4:3 in the "Aspect Correction" panel. I haven't been able to figure if the latter modies the PAR.

[DB83]

simple maths.

480*360 = 4(*120) * 3(*120). Pixels are then square ie the PAR is 1:1

[Djard]

Thanks. I am humbled by all the kind help I always receive at this forum.