Resolution question ^^

jade_eyed_angel · Post by **jade_eyed_angel** » Wed Mar 15, 2006 11:49 pm

Just need a suggestion on something.. if anyone can help...
all my dvd footage is 720 480 and i generally like that resolution, i don't want to resize it to 640 480 because then it ends up looking squished half the time, and I don't want to crop off anything off the sides... so I've been saving my vids at 640 420, which looks the same as the 720 480 resolution... theres like a .0238.... difference in the ratio... so i think it's good for saving on vid size and I can therefore make the vid shinier... or something
but anyway, i did that for about three vids and people complain... why? i know it's not a standard resolution but it looks the same on full screen... so basically i just want to know, is there a technical reason for why i shouldn't use that resolution? does it affect the actual vid in some way? or do people just like complaining? Just trying to figure it out so that i know what resolution to save my next vid on....

Kalium · Post by **Kalium** » Wed Mar 15, 2006 11:58 pm

TV pixels are 4:3, so 720 by 480 stuff looks right on them. Computer monitor pixels are 1:1, so 640 by 480 looks right.

Purge · Post by **Purge** » Wed Mar 15, 2006 11:58 pm

I would just keep the ratio at 3:2 so it would be 630 x 420 for your case.

jade_eyed_angel · Post by **jade_eyed_angel** » Thu Mar 16, 2006 12:00 am

Oh yea.. it is 630... why am in calculus, can't count... ^^;
thanks =]

Willen · Post by **Willen** » Thu Mar 16, 2006 12:05 am

It is supposed to look "squished" when you resize it from 720 x 480 to 640 x 480. Find a scene where there is an object the shape of a circle, a shot of the sun or moon will do nicely. Now, viewing it in 720 x 480 unadjusted for 4:3 aspect ratio, the image of your circle will look a bit like a oval, wider than tall. Resize that image to 640 x 480 and you will notice the circle is a proper circle.

This is the portion of EADFAG that deals with this.

I may post pictures to show examples later. EADFAG's section gets pretty technical and doesn't properly show or tell why you need to resize 720 x 480 resolution DVD footage when you make your final encode to 640 x 480 or similar aspect ratio resolutions.

Kalium · Post by **Kalium** » Thu Mar 16, 2006 12:05 am

Purge wrote:I would just keep the ratio at 3:2 so it would be 630 x 420 for your case.

Rather pointless, really. DVDs are meant to be watched in either 16:9 or 4:3. 720 by 480 is neither, and doesn't really look good at any point.

jade_eyed_angel wrote:Oh yea.. it is 630... why am in calculus, can't count... ^^;

Nor can a number of mathematicians I know. Don't feel bad.

Purge · Post by **Purge** » Thu Mar 16, 2006 12:11 am

gah 630 isn't a multiple of 4 so you could have some probs in vdub i think.

Qyot27 · Post by **Qyot27** » Thu Mar 16, 2006 12:12 am

I'd say it's both what Kalium said and that people just like to complain. I will say that it is sometimes possible to pull a fast one over on people and radically distort aspect ratio without them noticing (or at least not taking offence to it), but it usually centers around doing it as an artistic effect - however this probably only works with distorting 4:3 out to 16:9 without cropping the top or bottom off.

If you really want to bypass the issue entirely, you could always use a container that supports setting aspect flags so that (in the right player setup) the 4:3 is preserved when played back or put on fullscreen. I'm more accustommed to 720x480 because I edit at that resolution and get used to seeing it that way, but for the last few videos I've done, I just made sure that the display size in the MKV was set to 640x480 and so as long as VLC or mplayer gets used it'll display right, although WMP still shows it at 720x480.

(obviously that wouldn't apply if you're set on sticking with AVI, though)

Qyot27 · Post by **Qyot27** » Thu Mar 16, 2006 12:14 am

Purge wrote:gah 630 isn't a multiple of 4 so you could have some probs in vdub i think.

It's also not a multiple of 16, so most distro-centric compression formats (i.e. XviD or H.264/AVC) wouldn't like it much either. 640, on the other hand, does fit those requirements.

jade_eyed_angel · Post by **jade_eyed_angel** » Thu Mar 16, 2006 12:18 am

Willen - thanks! yea, guide makes sense, i guess...

Qyot27 - I just like editing in 720 since I don't want to make changes to the original image. yea i work with avi heh...

Kalium - Lol.. true XD

anyways thanks for the suggestions. I'm tempted to go with 640 now, so yea that helped =D