I've converted a bunch of Avi files to m2v with TMPGENC with no problem but one has suddenly come up.

With some that come from a different source than the first ones I did I only get a black screen for the m2v. Not only that but the 11:00 minute video is cut down to 6:30 minutes.

The original files for a video about the same size took about 2 hours or so, the new ones are only taking half that.

I've played with the frame rate settings but no change.

Any help or any points in the right direction would be appreciated.