If you're using Windows or Linux, definitely check out WinFF. It's also an effective movie file converter.
http://winff.org/html_new/
From the site:
* Easy to use interface.
* Fast (Winff does not hinder FFmpeg in anyway).
* High quality output.
* Converts multiple different files all to the same format at once.
* Convert video to audio.
* Convert between audio formats.
* No external codecs needed.
* Includes a variety of preset conversion settings for common formats and devices.
* Preset conversions can be created to encode to any format FFmpeg supports.
* Easy access to common conversion options such as bitrate, frame size, frame rate.
* Specify additional command line parameters for advanced users (options button).
* Easily change FFmpeg versions.
* Supports FFmpeg's multi threading for dual core processors
* Multilingual, available in over 10 languages