DV as 16:9 to divx 16:9 aspect ratio loss

[lawpan]

When I convert my 16:9 DV footage to divx with VirtualDub I loose the pixel aspect ratio.

Before conversion I play the DV in mediaplayer and its widescreen(I see black strip at top and bottom in normal and fullscreeen mode).

When I do the conversion to DIVX and play it with mediaplayer (or other player) the avi is 4:3 and things does not look what I expect.

How do I preserve the 16:9, I though that codecs did not care about the aspect ratio.

[lawpan]

I resized my video to 720 x 396 to get the 16:9 ratio. Now I can see the correct video on my computer.
I did it with a filter in virtualdub and in the Divx 5.0.5 with same result.

But is this the proper way? Anyone help?
I don't like the feeling cutting away a lot o pixels.
If I knew this I would never shot in 16:9 on my Sony TRV80.

And I heard that the width and height should be in a factor of 16 pixels. Meaning that 396 pixel is not devided even by 16.

Does this have something to do with the compression algorithm of the codec?

[Gazorgan]

Certain codecs (XviD and DivX included) need aspect ratios that are multiples of something. 2 is a minimum, but some are 8 or 16 (varies with codec/version). I believe DivX5 is multiple of 8. Multiples of 16 are safe for about everything.... and explains certain resolutions you see like 720*400 (not quite 16:9) or 640*360 (16:9 but ratio of 8).