aspect ratio issues ffmpegX

[wiserthanu]

Hi ... Im using ffmegX 0.0.9w to convert VOB to AVI DivX.

Trouble is that the aspect ratio changes after converting.

The original VOB movie file is mpeg-2, 720x576, 8000 kbps, 25 fps (PAL) and the target format I chose was AVI DivX with the same size 720x576 at maybe 5000kbps.

BUT the mpeg4 file I get is at 640x352. So the result is a different aspect ratio. It appears stretched horizontally. So I hit the "video" tab and in video parameters I enter 720x576 - hoping to keep the same ratio as the original. But this still distorts the image horizontally.

Really would appreciate advice on this one being new to all this.
thanxx all. I'm kind of new at this .. have had some training in video editing (yes that magnetic tape stuff!) ages ago but got myself a nice G5 tower so ... want to update the skills!

[Case]

MPEG (VCD/SVCD/DVD) generally does not have square pixels, while AVI and MP4 generally do have square pixels. This means you should not use the same pixel values for size when converting from/to MPEG, but re-calculate width or height based on frame aspect ratio and pixel aspect ratio.

If your VOB file is for 4:3 screens, then convert to e.g. 720x544 or 640x480 by using the Autosize 4:3 selection, which re-calculates the height for the given width.

[wiserthanu]

thanks heaps ... clear and easy to follow. Did what you said and it makes sense.