Avi is a pretty old multimedia container invented by Microsoft. It’s still widely in use and supports few different codes etc but its ability to handle errors or the durability is certainly not that good. I’ve had videos that I downloaded (legal ones okay! 🙂 ) which refused to play afterwards due to those bad error handling ability of this multimedia container.
Most of the time this is due to the index file corruption which is fixable in most situations. Although some players such as VLC or MPLayer for instance has the ability to fix it on the fly but there can be situations where you can watch a video but simply cannot use the ‘progress bar’ button.
In those cases your best hope is to find a utility that repairs those corrupted portions of the Avi container and when it comes to that, GPL licensed DivFix++ is one of the best!. Another benefit here is that this is designed using the wxWidgets framework so you can easily use it under Ubuntu (or many other GNU/Linux operating systems) other than MS Windows or Mac OSX.
*. Simple UI window.
*. Fixes index related errors easily.
*. Removes bad frames (you know, the non-fixable ones) but you can disable it.
*. Scans files for errors (has a separate log window which displays the output).
*. Manually removes the index file out of the multimedia container (beware that this will make the original file un-seekable in most situations).
You can easily install DivFix++ in Ubuntu 11.04 Natty Narwhal, 11.10 Oneiric Ocelot, 10.10 … all the way down to 8.10! by first downloading the “.deb” file from here.
Once the download completes double click on the file which should open the Ubuntu Software Center and the rest is pretty easy. Good luck.