The WebM video format popularity is increasing steadily, which is designed to provide users with high-quality video compression to use with HTML5. In this page, I will show you a brief tutorial explaining how to convert all video formats supported by FFMPEG to WebM.
Now to Convert video to WebM enter following command (Enter your video-name+extension and enter ouput name):
sudo apt-get install ffmpeg
Just like above you can convert many formats to WebM:
ffmpeg -i input.avi output.webm
ffmpeg -i input.avi -acodec libvorbis -ac 2 -ab 96k -ar 44100 -b 345k -s 640x360 output.webm