vcd/svcd image larger than tvscreen

[ogjan]

Hi - can anyone tell me why the imagesize from my burned vcd/svcd discs is larger than the tvscreen its shown on ??.
The problem is the same when its about mpgs converted from ntsc to pal and when its from captured homevideo. I use TMPGencs template to convert both into svcd and the tv screen is a normal (Bang&Olufsen) tvset, 4x3 format.
The image is cut in both dimensions as if it was zoomed into and the disc is played from a dvdplayer, I believe configured to the tvset correctly.
Thanks.

[MarcoEsc]

It's called "overscan", and the quick answer is "that's how TV works."

If you look at a camcorder or video editing program, you'll see "safe areas" marked off on the screen. Stuff outside of the safe area will likely not be visable on your TV, but you'll be able to see it on a computer monitor.

This article discusses, somewhat
http://www.ucalgary.ca/~tstronds/nostalghia.com/TheTopics/Overscan.html
(apologies in advance if the article sucks; it was a quick Google result)

You can either learn to love it, or shrink your source material (add black bars on the edges) so that nothing is lost.

[MarcoEsc]

From the cited article:

Typical televisions and many monitors lose nearly 20% of the picture by "cropping" the image. It is this lost portion that is commonly referred to as overscan. The information is not actually "lost," but it has been banished to an existence off-screen, in the twilight-zone found just beyond the borders of the visible area of your TV screen. Overscan is done intentionally, often to conceal a deficient TV/monitor power supply and/or video processing circuitry. It is intended to ensure, among other things, that screen real-estate remains filled and geometrically accurate at all times despite power fluctuations and dynamic swings in picture brightness.

[ogjan]

Thanks Marco !! - already a great help.
Now I just need to figure out how to shrink the imagesize. In TMPGenc the only way I found to put black frames around the image also cuts the image which gives the same result as the overscanned tv-showing. Or is it actually in the "extra" settings box where I can customize the image size ?...it puzzles me.
Maybe you would advice me this bit further too ?.....

[JürgenMUC]

I described in step 19 and 20 of my guide in https://www.videohelp.com/forum/userguides/151983.php the way to crop the picture in TMPEG.

Jürgen

[Randall Flagg]

Would this method of calculating (it looks like you multiply by 8% and round that up to the nearest number divisible by 4 and then subtract) work for encoding to DVD? I am having the problem (as quite a few others on the forum seem to have had) that the subs on fansubbed anime get slightly cut into because of the overscan.

[vitualis]

You can use the Official VCDHelp.com Demo VCD to measure the degree of overscan: https://www.videohelp.com/vcd

Generally, on most modern TVs, it will be in the order of around 5% on most sides.

Regards.

[JürgenMUC]

Hello Randall,

in fact you crop the picture for an mpeg video stream inside of TMPEnc. So you can use this method also for DVDs. You can choose every image size for cropping according your needs even odd values. You need not to respects any standards because the picture size remains allways the same (e.g. 720x576 pixels for DVD) but the black border size inside of the picture will be defined by the center Video arrange method.

Jürgen

[Randall Flagg]

Hello Randall,

in fact you crop the picture for an mpeg video stream inside of TMPEnc. So you can use this method also for DVDs. You can choose every image size for cropping according your needs even odd values. You need not to respects any standards because the picture size remains allways the same (e.g. 720x576 pixels for DVD) but the black border size inside of the picture will be defined by the center Video arrange method.

Jürgen

Many thanks for the help. I've played around and found that 660x440 works perfect on my TV.