ffmpeg

Previously named libav a like audio, v like video

Require package ffmpeg (previously libav-tools)

Codec of file

avprobe file.mp4

Note: could use ohter file like .flv, .avi, ...

Supported formats

ffmpeg -formats

Supported codecs

ffmpeg -codecs

Note: To have more codec, check libavcodec-extra-...

Example

ffmpeg -i input.flv -acodec aac -vcodec h264 -o output.mp4

Tips

Reduce the size of a video

avconv -i input.mp4 -c:v libx264 -crf 28 -c:a copy output.mp4

source

Convert mp4 to mp3

ffmpeg -i input.mp4 -c:a libmp3lame output.mp3