Log in

View Full Version : Image aspect ratio 2.21:1

peteag
29th June 2005, 22:23
What is that? All DVDs I know only supports 16:9 or 4:3. What is this 2.21:1 and how to use it?
unskinnyboy
29th June 2005, 22:32
Kindly read this (http://www.doom9.org/aspectratios.htm) and report back.
SeeMoreDigital
29th June 2005, 22:48
Kindly read this (http://www.doom9.org/aspectratios.htm) and report back.Do you mean this (http://www.doom9.org/index.html?/aspectratios.htm) link?


Cheers
unskinnyboy
29th June 2005, 22:54
Do you mean this (http://www.doom9.org/index.html?/aspectratios.htm) link?


Cheers
What's the difference? Both points to the same location.
peteag
29th June 2005, 22:57
nothing about the ar i've searched for!
unskinnyboy
29th June 2005, 23:05
Of course there won't be anything specific about 2.21:1 since this is just another frame aspect ratio. But the guide does speak about 1.85:1, 1.33:1 etc, right? Same principles and logic is applicable to 2.21:1 too.

Also, please :search:, this is basic stuff and asked and answered many times before.
zambelli
8th July 2005, 20:06
I might be wrong, but I don't think the OP asked what aspect ratios are. I believe he asked why does 2.21:1 exist as an option in MPEG encoders if no player takes advantage of it.
peteag
8th July 2005, 21:09
right, thats it!
petermg
23rd July 2005, 01:37
Wow.. and no one can reply to peteag's question?
SeeMoreDigital
23rd July 2005, 08:23
As you are all most probably aware, DVD uses "aspect ratio signalling" based on DAR (Display Aspect Ratio) calculations.

The most popular display screens have ratios of 4:3 (1.3333:1) and 16:9 (1.7777:1). As far as I'm aware, there are no display screens with ratios of 2.21:1........ so it's never been adopted - or ever likely to be now!


Cheers
peteag
23rd July 2005, 10:10
but is it possible to burn a dvd in that DAR for watching on a non 2.21-screen?
SeeMoreDigital
23rd July 2005, 10:29
I guess it could be possible to assign 2.21:1 aspect ratio signalling to an MPEG-2 video stream....

A 720x576 DVD image after PAL 4:3 DAR signalling has been applied acheives a target size of 768x576 (ie: perfect 4:3)
A 720x576 DVD image after PAL 16:3 DAR signalling has been applied acheives a target size of 1024x576 (ie: perfect 16:9)

A 720x576 DVD image after PAL 2.21:1 DAR signalling has been applied would acheive a target size of 1272.96x576.... Which is pretty pointless... So why would anybody want to do this?


Cheers