CVD aspect ratio

[mats.hogberg]

I've mostly done (X)VCD, but recently tried my hands at a CVD. When I play it on my standalone, I can only see about 1/2 - 2/3 of the upper part of the picture, and no matter how I set my telly, (4:3, 16:9, zoom...) the picture is almost as squashed as it is after encoding a 16:9 source (which it is) to 352*576. Looks fine when played with WinDVD on the box tho... Now, I figured this might be because in TMPGEnc, I had the aspect ration set to 1:1 VGA (an old VCD habit of mine...) and not 16:9? Quite as expected, when looking at the header of the m2v file with a hex editor, the aspect ratio flag is set to 1 (=1:1). Might this mpeg display correctly if I change this to 3 (=16:9)?

/Mats

[wway]

Assuming you are making a mpeg-2 file from a wide screen (PAL) source...the settings should be:

Video ---> Aspect Ratio = 4:3 Display

Advanced
---> Source Aspect Ratio = 16:9 625 line (PAL)
---> Video arrange method = Full screen (keep aspect ratio)


wway

[Vejita-sama]

http://www.doom9.org/aspectratios.htm

http://www.thedigitalbits.com/articles/anamorphic/aspectratios/widescreenorama.html

The Display aspect ratio of all VCDs, SVCDs, and CVDs is 4:3, period. Much like the DAR of standard TVs is 4:3. Here's a summary of how it works:

1:1 PC video - in theory all PC video should have a DAR of 1:1 but a lot of DivX and other sources are very poorly encoded.

4:3 Standard TV. This is only DAR a standard TV can display, the same is true for VHS tapes, VCDs, SVCDs and CVDs. Be they white book standard VCDs or xVCDs, they can only have a DAR of 4:3

16:9 Film and widescreen TV. However under the general flag of 16:9 you'll find -

1.77:1 widescreen TVs (and most HDTVs)
1.85:1 academy flat
2.35:1 anamorphic wide screen

In order to display a 16:9 source on our 4:3 TVs and perserve the aspect ratio you have to letterbox the video (add black bars to the top/bottom of the video).

That is VHS tapes and x(S)VCDs (and movies shown on TV broadcast). However with the introduction of DVDs this all changed.

Most DVDs released today are anamorphic. That is the video takes up the full 720x480 resolution (no black bars) and is then flagged as 4:3 or 16:9. If you play a anamorphic DVD that's flagged as 16:9 on a standard TV the DVD will letterbox the video ON THE FLY. If you play it on a 16:9 TV, no changes are made.

Here's were people get confused. If your source is Divx/xvid/avi etc. (ie. pc video) the source DAR in TMPGenc should be set to 1:1 because ALL PC video (correctly encoded) has a DAR of 1:1.

If you source is a DVD rip, DV/analog capture then you can set it to 4:3. You really only set a source as 16:9 from a DVD rip. The output should be set to 4:3 for x(S)VCDs and CVDs. And of cource video arrange method is 'full screen (keep aspect ratio).'

The key is the full screen keep aspect ratio. This will letterbox the encoded video to maintain the aspec ratio of the source. Take a look at the above links for more info.

[wway]

Actually, thats the answer i wanted to give. I just didnt have time last night.

Thanks for the info Vejita-sama.


wway

[mats.hogberg]

FYI:

Might this mpeg display correctly if I change this to 3 (=16:9)?

It did! Saved me 8 hours of reencoding. It looks beautiful to boot.
As I own a 16:9 TV, and only watch my (S)VCD/CVD on that, I'm not concerned with making it look good on a 4:3 too.

/Mats