DVD to .avi - resultant .avi looks distorted...

[abeelandig]

Hi,
I used VirtualDubMod to convert a DVD VOB file to a divx .avi file. This worked fine, but the resultant .avi file looks stretched in the vertical direction leaving the appearance of the video distorted. So, for example, a circle now looks like an oval. Hope that makes sense. Is there anyway to correct this?
Thanks in advance for any advice/help.

[tim6661234]

Your problem is aspect ratio. MPEG files have an aspect ratio as part of their header eg 4:3 , 16:9.
Thats why a PAL DVD resolusion of 720 by 576 looks the same as a NTSC thats 720 by 480 when viewed on a TV. Basically the way the picture sizes does not rely on the nuber of pixels or the ratio of horizontal and vertical pixels, the image is sized based on the ratio specified in the header.

Divx does not have this feature so you need to convert to a frame size that matches the aspect ratio of the disk.

eg 720 by 480 Mpeg ratio 4:3 to 720 by 540 for 4:3 or 720 by 404 for 16:9

I suspect you've done what I've done before and converted to 720 x 480 and everyone looks very tall

[abeelandig]

Thanks for your reply.
"you need to convert to a frame size that matches the aspect ratio of the disk. "
Can this be done with VirtualDub?

[tim6661234]

Yes use the resize filter

[abeelandig]

Thanks.

[celtic_druid]

You can use MPEG4Modifier to set the PAR of a DivX avi file. With XviD you can set it in the config when encoding. File will playback correctly with mplayer, VLC, XBMC, via ffdshow and XviD decoder (doesn't work 100%). Don't think that DivX's decoder supports PAR resizing and I am also not sure if any hardware players can.