mp4 aspect ratio correction?

[iThinkYouBrokeIt]

I have an MP4 video which is encoded at 480p resolution and is supposed to have a 16x9 aspect ratio.
When i play it, it plays back as if its square pixels, which makes it 1.5:1 instead of 1.78:1 as it should be.
Is there a way to edit the aspect ratio tag in an mp4 video without re-encoding? I know how to do this with mpeg-2 but i've never had to do it with mpeg-4 before.

and the encoder seems to have no option of giving it an aspect ratio tag at time of encoding.

thanks........

[Chris K]

Perhaps this will do... http://www.moitah.net

Chris.

[guns1inger]

mpeg-4 modifier only does Divx/Xvid variants, and not .mp4 or AVC type Mpeg-4 variants. I believe it only works on the avi container as well.

[Baldrick]

Maybe YAMB can fix it. Or it might be 16:9 but your player ignores it.