Advanced Video Compressor 2011 is an interesting application that will convert videos into the format of your choice, reducing their file size as much as possible while still retaining good image quality.
The program imports most video formats: AVI, MPEG-2, MP4, 3GP, MOV, 3GP, FLV, WMV, WebM and more. Output is a little more restrictive - it can create files in the original file format, AVI, MP4, 3GP or FLV - but that's still sufficient for most applications.
You're able to customise all the important aspects of your output video: the frame size, frame rate, video and audio codec, video and audio bitrate, and more. But Advanced Video Compressor 2011 also comes with a set of profiles which contain the appropriate settings for common tasks. So if you're creating videos for the iPhone, iPod or iPod Nano, or to upload to Facebook or YouTube, then just choose that profile from the list and everything else will be configured for you.
The compression engine itself isn't the fastest we've seen. It did a reasonable job, though, dramatically reducing the size of our test video while preserving much of the image quality. And if a particular job is running longer than you expected, then the program does at least allow you to pause the transcoding process, so you can resume again later when it's more convenient.
Please note, this trial version adds a watermark to any videos it creates. Purchasing a licence will remove this.