Resizing VCDs manually : LUSENET : Video CD : One Thread

I would like to know how to resize VCDs manually. For example: I have got a nasty avi-file with black borders and completely wrong aspect ratio, but I know the aspect ratio the picture is suppossed to have. The aspect ratio is 2.35 and I cropped away all the black stuff around the picture. Now, how do I CALCULATE how to get the right height for the picture and corresponding to that the size of the black bars to add, if I want a VCD resolution of 480x576. Or maybe in the future I would like to use a different resolution, or I got another aspect ratio. So whats the CALCULATION for the right aspect ratio of VCDs?

Greetings, Sebastian

-- Sebastian Meier (, November 02, 2004


A video CD comes in two resolutions only, 352x240 for NTSC and 352x288 for PAL. Any other resolution/aspect/size is not VCD compliant.

In order to make a VCD from widescreen material, it is necessary to manually pad the video material with black bars to bring the size up to something that will resize easily. Usually, this means padding the material so it's 740x576 for a PAL image. This will resize evenly down to 352x288. The reason for needing the black bars on a VCD is becuase VCD does not have a 16x9 mode like DVD does.

How to calculate the size of the bars? How big is your picture? if it's already something smaller than 352x288, just add pixels until you reach that size. If it's larger and you want to keep the aspect ratio you have, add pixels until you reach 740x576.

There may be programs out there that can do this to the .mpg file, but I don't have a clue as to what they are. I re-write the file as a raw or lightly compressed .avi using virtualdub and the internal resize filter to add bars or resize the picture if need be. I compress it down to VCD using TMPGEnc. This isn't the easiet way to do it, but it's the cheapest and yields good results. It does require lots of disk space, however.

If you already have a picture that is correct, but it is letterboxed (has black bars,) use that directly and compress it using TMPGEnc. Just be aware that TMPGEnc has problems with some .avi codecs, which is why I like to write out a raw .avi before re-compressing.

-- Bryan (, November 02, 2004.

I know about the VCD standard. That it's resolution is 352x288 (PAL) and that you have to add black bars to get an other aspect ratio than 4:3. Actually, what I forgot to name, is that I don't want to make a standard VCD. But it doesn't even matter, what resolution I use. The question I had, was what I have to calculate to get the right height of the picture and the black bars, so when I view the movie on a 4:3 TV, the movie is having the correct aspect ratio of 2.35. Because if the black bars are to big, the heads are squeezed and if they are too small, I get eggheads. I know how to add the black bars (AviSynth) and how to encode (TMPGEnc) - anf if it helps you, I want to make a MVCD with the resolution 480x576 and the movie has a aspect ratio of 2.35. I know that there are programs like FitCD and others to do that resizing, but I want to to it by hand. Take a piece of sheet and a pencil, maybe a caculator would also help and calculate it by myself. What I would like to know from you, what I need to calculate.

Greetings, Sebastian

-- Sebastian Meier (, November 03, 2004.

There really isn't an easy way to get the picture back if someone has encoded it wrong to start with. Every time you re-encode, it's going to get a little worse.

The easiest way I know to do this is use AVISynth's built-in resize filter to squash or stretch the picture until it looks right to you. Find something round, like a clock or a wheel, and use that as a guide. You don't need to remove the black bars already there - stretching a black line is still going to give a black line.

After that, it's a matter of subtracting the wanted size (480) from the actual size (Say, 400) - divide this number (80) by two and add that many lines of black to the top and bottom. If it's not even, it doens't really matter, just add one more on the top or bottom.

-- Bryan (, November 04, 2004.

Moderation questions? read the FAQ