Calculator Question

[tb582]

Quick question,

I'm using this calculator here: http://www.divx-digest.com/software/video_resize_calc.html - and when I enter in 1920x1080 - how come I get 1280x720 as valid but not 960x540 OR 704x396??

[edDV]

Valid for what?

[tb582]

Valid for what?

In the calculator under "available valid resolutions"

[edDV]

What are you trying to accomplish?

960x540 is quarter resolution, half motion sample of 1920x1080i that is the poor man's deinterlace favored so much by Apple.

[tb582]

I'm just trying to figure out the possible frame sizes with an particular aspect ratio.... and I know that 960x540 & 704x396 should be listed. Do you know of a calculator that will give me all the possible listings?

[edDV]

I'm just trying to figure out the possible frame sizes with an particular aspect ratio.... and I know that 960x540 & 704x396 should be listed. Do you know of a calculator that will give me all the possible listings?

It depends again on target.

If you stay with square pixels, any 16:9 ratio will maintain aspect ratio. If you are working with non-square pixels, the choices are limited by the codec and media format you intend to use.

[minidv2dvd]

Quick question,

I'm using this calculator here: http://www.divx-digest.com/software/video_resize_calc.html - and when I enter in 1920x1080 - how come I get 1280x720 as valid but not 960x540 OR 704x396??

it might be because that program hasn't been updated in 8 years.

not sure why you would need a calculator to get a valid 16/9 size. just choose your horizontal pixel number multiply by 9 and then divide by 16.

[tb582]

[quote="minidv2dvd"]

Quick question,

not sure why you would need a calculator to get a valid 16/9 size. just choose your horizontal pixel number multiply by 9 and then divide by 16.

what about for a 2.35.1 or 2.40.1?

[edDV]

[quote="tb582"]

Quick question,

not sure why you would need a calculator to get a valid 16/9 size. just choose your horizontal pixel number multiply by 9 and then divide by 16.

what about for a 2.35.1 or 2.40.1?

for 1920 horizontal pixels in,

1920/2.40=800 vertical pixels or 1920x800

[minidv2dvd]

take your horizontal and divide by the aspect ratio, i.e. 1920/2.35=960

16/9 is 1.77777777....... so 1280/1.77777777=720.00000315


[edit] point to eddv for faster typing

[tb582]

math was never my thing so forgive my ignorance but why with the 16:9 do you take the horizontal number multiply by 9 then divide by 16, vs with the 2:40.1 you take the horizontal number and divide only by 2.40?

[guns1inger]

Do a goole search for Aspect Ratio Calculators and you will find a lot of them out there, including simple ones like this : http://andrew.hedges.name/experiments/aspect_ratio/ which works for 1:1 PAR.

[edDV]

16:9 and 1.777777777to1 are two ways to say the same thing. It is a simple ratio. We aren't even doing algebra here.

[tb582]

How about a 2:40:1 video at 1920x800 - I want to keep the DAR 12:5 and PAR at 1:1

[JohnnyMalaria]

Neither 540 nor 396 are exact multiples of 8 (or 16). That's probably the reason.