FORUMS: list search recent posts

A little guidance regarding scale down resolutions

COW Forums : Compression Techniques

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Daniel De Avila
A little guidance regarding scale down resolutions
on Mar 26, 2008 at 2:48:53 pm

Hello

Just curious if what I’m doing is a good general workflow or…are there alternatives?

When I encode standard definition clips for computer playback, web or CDROM, I usually do a proportional scale down, depending on the job specifications. For example: Master video is PAL 720 x 576 with a proportional scale down to the following resolutions:
75% of source 540 x 432
50% of source 360 x 288
25% of source 180 x 144

I guess it’s the same workflow for HD clips. So
1280 x 720
75% of source 960 x 540
50% of source 640 x 360
25% of source 320 x 180

I guess I can also calculate based off aspect ratio –
Multiply the desired height or width by 1.778 or .5625 (for 16:9 material)

What’s the question???

Hmmm…Does the above sound logical? Can I be doing something wrong?

Daniel





Return to posts index

Daniel Low
Re: A little guidance regarding scale down resolutions
on Mar 26, 2008 at 2:59:39 pm

Your standard def aspect ratios are wrong. Remember that 720x576 is 4:3 (1.333) using non-square pixels. Web CDROM etc all use square pixels.

Although the following link relates to flash video, the frame size tables are relevant for all square pixel delivery formats:

http://blog.influxis.com/influxis/?p=14




__________________________________________________________________
Please post back saying what solved your problem. It could help others, and saying 'thanks' is free!


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]