How to convert 4:3 aspect ratio source to 16:9 (correctly)?

[SplinterMgs]

Hi all

Sorry if this isn't the right forum to ask. I'm a newbie and tried using dvd2dvdr/cce on a 4:3 source video by setting the (display) aspect ratio to 16:9 and re-encoding. The resultant video when played back using PowerDVD does present itself as widescreen but unfortunately the actual image is incorrectly stretched.

How would one go about converting the source video from 4:3 to 16:9 format correctly (image correctly resized)? What programs would I need to do this without compromising the source video quality?

Any feedback most welcomed, many thanks in advance.

[daynight]

Hi.
To avoid distortion you have to do cropping. Get tmpgenc (a newer version please to be able to open your mpeg2 file), select settings, go to advanced tab, set video arrange methode to full screen, double-click clip frame, select an area with size about 720:430**, hit ok, tick clip frame, select source aspect ratio 1:1, go to video tab, set aspect ratio 16:9 display and set resolution 720x576 mpeg2. Ready for encoding.
I have already tested the above for you. Good luck.

[daynight]

Further to my previous comments
**Why 430? An mpeg2 clip 720x576 with DAR 4:3 is to be displayed correctly as 768:576. The equivalent to 16:9 is 768:430. So we have to leave out 146 horizontal lines (576-146=430). Complicated?

[mpucoder]

Note: The number of lines when cropping to 16:9 is 3/4 that of the original. For NTSC it is 480*.75 = 360, for PAL 768*.75 = 432
It is also important that the dimensions be evenly divisible by 16 for efficient mpeg encoding, which these values are.

I don't know why you would want to throw away part of the film just to fill a widescreen display. Most widescreen televisions allow you to do this while watching a 4:3 movie anyway, in case it was letterboxed. That reminds me, you will need to mark the video as 4:3 letterboxed (not 16:9 with auto-letterbox), you could do this anyway without cropping, and watch the fullscreen by telling the player the display is 4:3, and a cropped and zoomed version on widescreen by setting the player display mode to widescreen.

[daynight]

thanks mpucoder for correcting me.

[SplinterMgs]

Thanks for all the suggestions. It does sound rather complicated (confusing) but I'll give them a try and see how they go.

Another question I still have is does resizing (re-encoding) the DAR affect the video quality? Thanks again.

[Toti]

Hello guys, Thanks for your input, I started doing some math calculations to see what would be the correct way to do it. Since daynight (thanks) guided me through TMPGEnc I found a way to do it.

In the Advance tab select Center Custom Size then the number below depends on the original source. If it is 2.35 then

2.35* (9/16) * 480(NTSC) = 634.5

So enter 720 by 634. The video will be encoded correctly.

let me know your thoughts

[mpucoder]

The original aspect ratio doesn't matter. What you want to do is resize according to DVD aspect ratios, and they are 4:3 and 16:9. To resize a 4:3 letterboxed video to be 16:9 you expand the center 3/4 to the full height. That might still have some black bars, but that's OK, they are needed for ARs greater than 16:9 (1.77:1). Your example of 2.35:1 would still need black at the top and bottom.