In this tutorial we will see how to use FFMEG to convert videos having the MP4 extension to AVI. You may use video conversion tools like , but in this tutorial we will see how to do it only via the command line. To install ffmpeg in Ubuntu 11.10 or any older versions of Ubuntu, open the terminal and issue this command:
sudo apt-get install ffmpeg
Next, cd to the folder containing your MP4 files and run this command:
ffmpeg -i filename.mp4 -vcodec mpeg4 -acodec ac3 -ar 48000 -ab 192k output.avi
Replace filename.mp4 with your own MP4 file. The generated avi file will be named output.avi, you can rename it to whatever you want.