DVD aspect ratio question...

[MYoung]

Okay, so I want to take some images to a 4:3 NTSC DVD. I'm going to use AviSynth and load and duplicate BMP images and feed the script into TMpgEnc. My question is what resolution should I make the pictures? 720x480? I know I could just let TMpgEnc worry about apect ratio, but I want to understand this.

In addition, I have to allow for 5% on all sides of the TV frame to not be visible on many TVs, right? I heard it can be as much as 10% on all sides, but 5% is generally accepted.

So if I do make my images 720x480 then do I have to adjust the aspect ratio of the images? 720x480 is not 4:3. I know DVD doesn't have square pixels. So do DVD players take the 720x480 and squeeze it horizontally to be 4:3 when it is displayed?

It seems to me that I should crop my images to 640x480 and do a bicubic resize to 720x480. Does that sound correct?

Sorry if this question is basic. I should know this! Thanks!

[Baldrick]

Don't resize up. Make your images 1024x768 or higher with 4:3 aspect ratio and then resize to 720x480. The dvd will then stretch to correct aspect ratio.

[MYoung]

Damn, I'm just going to have to 'speriment and see what I get. DVD pixels are not square so if 720x480 is 4:3 then it must squeeze the image horizontally to get 4:3 from the 720x480. Thus, one must stretch an image from 4:3 (640x480 1:1) to (720/480):1. Encoders must do this stretching, right? Maybe I'll just keep it all 640x480 and let TMpgEnc deal with it since the video I wanna mix with the pictures is 640x480 1:1 from a MJPEG card.

[duhmez]

Easy peezy that is. 720x480 is not 4:3 that's true, but every DVD player knows this and resizes when you watch it. it's encoded stretched, then the playback squishes it normal. It is not because the pixels are wider......

Remember, you could have 352x480 and it would still look right on the screen when encoded 4:3.

[MYoung]

Alrighty, thanks! I guess I should just crop the images to 640x480 1:1 (which is 4:3) and let TMpgEnc do it's thing.

[duhmez]

Recomend you do what Baldrick says, don't resize below 640x480, make yor image larger like 1024x768, then resize to 720x480. mAKE SURE YOU SETUP TMPGENC EXACTLY RIGT TOO, OF THE MANY OPTIONS ON THE ADVANCED TAB, IT WILL ADD DIFFERENT A MOUNTS OF BLACK BORDER HERE AND THERE, if you choost the right one it wont add any border at all. (Oops caps lock my bad)