Setting ratios & borders

[carlmart]

An arithmetical question.

How do you compute correct aspect ratios and borders, so when I resize a file for DVD authoring I end up with the original relationship in a 16:9 screen?

For instance, let's suppose I have three different file formats which I got from MediaInfo:

1) 704:400

2) 1280:688

3) 704:288

Which math formula should be applied to get to an untrimmed correct size, with the right black borders (if any) up and below and no distorted image compared to the original? In NTSC, of course.

[poisondeathray]

You can use FitCD to help figure the stuff out

[minidv2dvd]

well ntsc dvd is 720x480. no other choices to encode to. there are others that work on dvds but not that you'd want to encode to. if it's 16/9 there is a flag the encoder sets to allow the dvd to be played in widescreen.

the first 2 are close to 1.77, the 3rd 2.35., so encode to 16/9 dvd specs and the encoder will add the borders.

any questions make sure to mention which editor/mpeg-2 encoder you are using.

[carlmart]

Sorry. I forgot to mention that these numbers were to know what should I load with avisynth.

For spline36resize() and addborders().

[poisondeathray]

FitCD will give you the avs script for borders and resize, just change lanczos to spline36 or whatever your choice

[guns1inger]

There are quite a few resize calculators around, some web based. Some go into detail on how they work - non-square pixels etc - most don't. Hell, I even wrote a simple one a few years back -> http://users.tpg.com.au/adslrotx/apps/AVI_RC2.zip (requires .net 1.1)