aspect ratio changes when converting

[wiserthanu]

Hi am using ffmegX 0.0.9w tpo convert VOB to AVI DivX. Trouble is that the aspect ratio changes after cconverting. The VOB is mpeg-2, 720x576, 8000 kbps, 25 fps (PAL) and the target format I chose was AVI DivX (mencoder mpeg4, 640x352, 1265 kbps, 25 fps, no crop). So the result is a a different aspect ratio. 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.
Really would appreciate advice on this one being new to all this.

Gianni

[drewzor]

deleted

[wiserthanu]

Thanks so much for your help here.

is it stretched tall?

720x576 to 640x352 is distorted by -2.27% you'd be closer if using 624x352 (.28%)

If its 720x576 which displayes widescreen then its anamorphic. Meaning the file is saved in a different aspect ratio to what it actually will play back as.

but for 16:9 setting it to 512x288 would be perfect if you can ?

720x576 displays on a puter at 768x432 16:9 thats why your encode with the "right ratio of 720x576" isn't working.
if its 4:3 the it will display at 768x576
hope this helps

No itplays stretched as in widescreen.
I guess I wasn't totally clear . I want to keep the same size as the original but thats not possible because you say "720x576 displays on a puter at 768x432". Or does that mean after I edit it then re-burn it to DVD movie again it will display normally on a TV monitor? Thats all I want. The original movie is in the old 4:3 screen ratio (PAL).
Again thanks. Should I repost this to the mac forum cause I've got a mac even though ffmpegX is mac/pc?

[manono]

Hi-

The original movie is in the old 4:3 screen ratio (PAL).

Maybe I'm not understanding, but you have a 1.33:1 "fullscreen" movie, and you resize it to 640x352, 1.82:1 "widescreen", and you're wondering why everyone looks short and fat?

Why didn't you make it 640x480 or 512x384 or some such?

[wiserthanu]

sorry I had a the original at 720x576 (4:3 older TV and movie screen ratio) and wanted to keep the same ratio and roughly the same size.
Someone at the mac forum helped me out:

"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."
Easy i went auto resize with 720x544. Learn something everyday. Here i was thinking all pixels were square...

thanks to both of you