My composition size is 640x380. I render it in H.264 format and the rendered movie is somewhat stretched with black bands on the top and the bottom.If I select .avi format, it renders fine. What am I doing wrong? should I change pixel aspect ration to 16x9 in H.264 format settings or keep it the same as in composition settings (square pixels)?
> My composition size is 640x380.
That's a very strange set of frame dimensions.
> I render it in H.264 format and the rendered movie is somewhat stretched with black bands on the top and the bottom.
The H.264 format only permits a limited, constrained set of frame sizes. In After Effects CS4, these constraints were communicated in the Comments field of the H.264 Export Settings dialog box. In After Effects CS5, if your settings don't match one of the sets of settings allowed by the H.264 specification, then a warning icon in the Output Module Settings dialog box appears, and After Effects tells you what it's going to do to make the video fit.
Sorry, it was a typo: comp size 640x360. The problem was with H.264 format settings. after I setup square pixels as in the composition settings, it renders correctly