source avi's you use ......

[nish]

....I was just wondering... I always download avi films which have pretty much the largest size avaiable (eg, 570 x 350) etc. But most of the films I do I put on vcd (mpeg 1) which are coded to 352 x 288. So am I better actually downloading avi's which are closer to this size (not only for speed, but for quality reasons?). And if so, would it apply to when making svcd's (would I be better off downloading files which are closer to mpeg2's 480 X 576).

Hope that made sense!

Thanx

N

[Ácaro]

Originally posted by nish
....I was just wondering... I always download avi films which have pretty much the largest size avaiable (eg, 570 x 350) etc.

What you call "size" doesn't have nothing to do with quality. If you want to chose, chose the biggest files (in bytes) available.
Then, when you produce the (S)VCD it's only a matter of respecting the aspect ratio.

Try to read more guides :)

[Buttfreak]

That's right. Don't try to match up the aspect ratio of the AVI (which will typically be 1.85:1 or 2.35:1) with the aspect ratio of the VCD (which in PAL is 1.22:1 before it's processed by the TV, read the excellent Basics guide to aspect ratios (http://www.doom9.org/aspectratios.htm) if you're interested in how this works.)

Like Ácaro says, the AVI with the largest resolution isn't necessarily the highest quality, it depends on the bitrate of that transfer which is harder to find out before you download it.

Also, it's worth iterating Ácaro's point that you have to "respect" the display aspect ratio ("DAR"). In other words, make sure the settings of TMPG will not distort your picture. If you set the arrange method to "Full Screen (Keep Aspect Ratio)" then you'll get a letterbox transfer. If you're interested in creating an anamorphic transfer for your widescreen TV it's a bit more complicated. You interested? Keep reading...

First of all, the VCD dimensions you quoted are PAL dimensions, so I assume you are in Europe. Bear in mind that most AVIs floating around on the web are NTSC (framerate of 23.976 instead of 25 fps). Unless you want to go through a complicated conversion process, you should make NTSC VCDs out of these AVIs instead (most likely your DVD player can play NTSC VCDs and your TV will too if it's larger than 14" and sold within the last five years).

So, say you have an AVI with a resolution of 640x272 (fairly common, I've seen these quite often) you have a 2.35:1 or CinemaScope movie. Even if you create an anamorphic VCD, you will have thin black bars, but how thin? Let's work it out.

1) The DAR of the source is 640/272 = 2.35

2) The dimensions of a NTSC VCD is 352x240. When you press the "16:9" or "Widescreen" button on your TV remote, this is stretched to 240 x 16/9 = 427 or 427x240

3) As you want the ultimate DAR to be 2.35:1 the width will be 427 (see above) and the height will be 427/2.35 = 181

4) The video stream you're creating in TMPG though will be stretched to this, so you keep the original standard width of 352 and just use your new, calculated height of 181

Now all you do in TMPG is set the video arrange method to "Custom Center" and enter the size you calculated: width of 352 and height of 182 (I usually round to the nearest even number). Now I know what you're thinking, this DAR is 352/182 = 1.93 nowhere near where you wanna be! But remember, this picture will be stretched once you press that "wide" button on your remote to 427/182 = 2.35 just like the doctor ordered.

I've created multiple VCDs and SVCDs with this method - both PAL and NTSC - and it works a charm. If you're sourcing from DVDs all you need to do is set the arrange method to "Full Screen".

Good luck!

/Buttfreak