Real-life accurate image ratio

[mcard]

I've been experimenting for days with various setups, and this issue has been bugging me, so I've finally decided to post for some help. Which of the following scenarios produces a real life accurate image ratio?

1. 640X480 source video that's imported into TMPGenc to produce 352X240 image for MPEG1 VCD (full screen keep aspect ratio).

2. 320X240 source that's imported into TMPGend to produce 352X240 image for MPEG1 VCD (full screen keep aspect ratio).

3. 320X240 source that's imported into TMPGend to produce 352X240 image for MPEG1 VCD (centered with black bars added to the sides to bring it up from 320 to 352 without stretching).

#3 looks to produce the most accurate image, with the exception of the black bars. Most of the black bars on the TV disappear, but you can still see some of it on the side. #1 and #2 produce an image that seems to be slightly stretched, but fills up the TV nicely. For example, when viewing a video of cars, all the cars seem to be wider and lower than they really are using methods #1 & #2.

[j1d10t]

But if you are encoding to be played on a 4:3 TV, and the source is 4:3, then it's all pretty much the same - just choose "full screen" when encoding. It's like watching an SVCD (480x480) - everything looks a little taller/thinner than it does on a VCD (352x240), and that is because you have doubled the vertical resolution, but not the horizontal. It will look fine on your 4:3 TV, just a little off on your computer.
Burn a small test of all of your settings on to a CDRW and play it on your TV. You'll see what I mean - things will look a little funky. Then burn one with the "full screen" setting, and see how it looks.

I may be wayyyyyy off here (as I consider myself still a newbie), but I don't think so - I'm speaking from personal experience. I've tried a bunch of settings trying to compensate for overscan.

[mcard]

Just to add to my previous post:

I've tested 2 scenerios:

1. 320X240 source, add black bars on the sides in Virutal Dub to bring the size up to 352X240, then create MPEG1 VCD as FULL SCREEN Keep Aspect Ratio in TMPGenc.

2. 320X240 source create MPEG1 VCD as FULL SCREEN Keep Aspect Ratio in TMPGenc.

When comparing the two, you can clearly see that #2 seems more "squished" and widened than method #1 which seems to display a more accurate real-life image. The results are similar going from 640X480 to 352X240 MPEG for VCD.

[vitualis]

Dude, you are missing the point.

There is something called display aspect ratio. That is, regardless of the pixel framesize, the end picture is resized to fit that aspect ratio.

For instance, VCDs and SVCDs are always displayed at a display aspect ratio of 4:3 (i.e., the same as your TV). You will note that the framesizes of VCDs and SVCDs (352x240/288 and 480x480/576) are nowhere near 4:3 in terms of SQUARE PIXELs. This is irrelevant, however.

On the TV, the framesize of the video clip is resized to fill the entire TV screen.

Have a look at the relevant article here: http://www.michaeltam.com

Something that "looks right" on your PC at S/VCD framesizes with Windows Media player is very rarely going to be right on your TV (i.e., it is actually wrong). The problem is that Windows Media player (version 7 and up) doesn't understand the concept of display aspect ratio. Rather, they assume that all video has a pixel aspect ratio of 1:1. This is not true.

I suggest you use Windows Media Player 6 (on your PC, press the Windows button + R to get the "run" option box and the type in mplayer2). Now, load your VCD spec MPEG file and play it at full screen (Alt+Enter). WMP6 supports DARs of 4:3 and will resize it at full screen to correctly reflect the DAR of 4:3...

Ultimately, if something begins as 640x480 and the picture fills up the entire frame, then it must also fill up the entire frame on a VCD (at 352x240/288) for there not to be a distortion when played on a TV.

Regards.

[Vejita-sama]

People often confuse DAR (display aspect ratio) with resolution. The two are NOT the same. In fact you can have a given DAR at any resolution. That's often confusing but here's a little background:

There are 3 DARs that you're likely to deal with:

1:1 PC
4:3 Standard TV
16:9 widescreen TV/film

Now under the 16:9 DAR flag there are infact several ratios:

1.77:1 widescreen TV
1.85:1 academy flat
2.35:1 anamorphic widescreen/cinescope

You TV can ONLY display 29.97fps interlaced video (it's a whole seperate converison to explain how you produce that but trust me, that's all it can do).

On the PC since the DAR 1:1 things that look 'normal' on the PC will not look right at the 4:3 DAR of your TV. Popular NTSC resolutions enclude:

720x480, 480x480, 352x480, 352x240

Notice that none of those divide out to 4:3 (1.33:1). How is that possible? Again resolution and DAR at not the same thing. The picture will be stretched/morphed as necessary to be displayed at 4:3 when played. That means it looks correct on the TV, but looks all f&cked up on the PC

Just stick to a NTSC (or PAL) safe resolution and everything will be fine.

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