Installation of FFMPEG

FFmpeg is a very fast video and audio converter that can also grab from a live audio/video source. It can also convert between arbitrary sample rates and resize video on the fly with a high quality polyphase filter.

1) Install ffmpeg gem 

sudo apt-get install ffmpeg

2)Install following required dependencies for video conversion

sudo apt-get install -y x264 libx264-123 libx264-dev libavcodec-extra-53

ffmpeg -i input_filename -b:v 64k -bufsize 64k output_filename

Command for to convert video from flv to mp4 

eg: ffmpeg -i input.flv -r 25 -y -sameq -vcodec libx264 output.mp4

-i      : filename (input) : input file name

-y      : Overwrite output files without asking.

-sameq  : same quantizers and should only be used to copy the quants from the input to the output of the same format

-r      : Set frame rate (Hz value, fraction or abbreviation).

-vcodec : Set the video codec. This is an alias for -codec:v.


Refer: http://ffmpeg.org/ffmpeg.html