Square pixels on a DVD?

douglas_clark wrote on 1/14/2007, 7:19 AM

Most of my work is for viewing on Internet, or computer or projector. All with square pixels. Some clients want a copy on DVD, for use in a DVD player. Is it possible make a DVD with a square pixel video, without conversion back to PAL (or NTSC) non-square pixels? I guess the correct question is does MPEG2 format support square pixels?

Comments

rs170a wrote on 1/14/2007, 7:30 AM

...does MPEG2 format support square pixels?

I've never done this but it sems to.
After selecting MPEG-2 as a render format, click Custom - Video.
Change the Aspect ratio setting to Square pixels.

Mike

Chienworks wrote on 1/14/2007, 9:50 AM

Yep, i've done this often. It works well on every DVD player i've tried. I won't guarantee it will work on all of them, but i haven't had any problems yet. I suppose some older players might show the image slightly distorted. Then again, many televisions distort the image anyway and we're all so used to that that no one ever seems to notice.

douglas_clark wrote on 1/14/2007, 1:55 PM

Thanks for the tip on the square-pixel option in MPEG2 render options. I'll give it a try.

I need a new DVD player, and want to make sure it can directly output a square-pixel MPEG2 video to a projector. What feature and/or type of connection should I be looking for? Ie, what is it usually called in specifications and/or manual? (I bought my present PAL DVD player in Beijing...and the remote control and manual are in chinese...so I have had a bit of a problem learning its "advanced features" ;-)

Laurence wrote on 1/14/2007, 2:40 PM

This is one of the cool things about HDV cameras and the HDV format in general: You can extract 960x540 30p video with no interpolation. This is enough to make beautiful progressive footage for the Internet.

Another thing I've done when it is going to be mainly an Internet viewed project is to shoot HDV in 30p frame mode and downconvert it on capture. This gives you 720x480 30p which can be rendered beautifully into various web formats yet looks great on DVD too. In fact, if you watch out for fast zooms and pans, it looks better on DVD than regular interlaced footage.

FuTz wrote on 1/14/2007, 8:18 PM

"we're all so used to that that no one ever seems to notice"

lol
Talk about those "tronics-depot stores"showrooms..!

douglas_clark wrote on 1/15/2007, 5:59 AM

Kelly, how are you using the square-pixel DVDs? DVD player with projector? What models and how do you set them up?

Chienworks wrote on 1/15/2007, 11:15 AM

Standard set-top DVD player, usually a sub $40 model from Wal*Mart, connected through an RF modulator to channel 3 on my 23 year old RCA tv set. I imagine if i checked very carefully i might see that people are a little bit skinnier in one format and a little bit fatter in the other. There's not enough difference for me to have ever noticed during casual viewing.

I also watch them on my computer screen a lot. Prior to Media Player 10 the 720x480 DVDs were all stretched out horizontally with a 3:2 frame size, while the 640x480 square pixel DVDs played normally. With Media Player 10 they both display properly.

douglas_clark wrote on 1/15/2007, 1:57 PM

It's not so much getting the aspect ratio correct as avoiding an aspect ratio or resolution conversion in the player or projector. I'm trying to get the sharpest reproduction in a DVD player-projector combination, for example to show screen capture video (originally in TSCC codec). I'm sure it will never look as good as when played on a computer, but will rendering the square-pixel video to square-pixel MPEG2 at least do better than ordinary PAL MPEG2?

Chienworks wrote on 1/15/2007, 3:18 PM

I would guess that ultimately you're at the mercy of the projection hardware. Unless you can find a projector with a native resolution that matches your video, it's going to be scaled when projected. Probably the only way around that is to show the video in a window less than full screen and match your computer's resolution to the projector's native resolution. But, that only helps if the player software doesn't scale. Media Player 10 should be fine as long as you set the window to 100%. Of course, this means that your video won't fill the projection screen.

I would guess that the fewer rescalings your video goes through the better. Rendering to square pixel output files that match the resolution of your source is probably the best way to go. At least you know you won't be adding in the DV pixel aspect ratio conversion that way.