Rtrack

RTrack is a object-oriented wrapper around ffmpeg to manipulate audiofiles easily from ruby code.

Installation

Add this line to your application's Gemfile:

gem 'rtrack'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rtrack

Usage

Open a wave file

require 'rtrack'

song = AudioTrack.from_file "never_gonna_give_you_up.wav"

...or a mp3 file

require 'rtrack'

song = AudioTrack.from_file "never_gonna_give_you_up.mp3"

... or an ogg, or flv, or anything else ffmpeg supports

ogg_version = AudioTrack.from_file "never_gonna_give_you_up.ogg"
flv_version = AudioTrack.from_file "never_gonna_give_you_up.flv"
mp4_version = AudioTrack.from_file "never_gonna_give_you_up.mp4"
wma_version = AudioTrack.from_file "never_gonna_give_you_up.wma"
aac_version = AudioTrack.from_file "never_gonna_give_you_up.aiff"

You can concatenate multiple AudioTracks together

song_one = AudioTrack.from_file "one_love.mp3"
song_two = AudioTrack.from_file "jamming.ogg"

song_three = song_one + song_two

song_four = song_one + song_two + song_three + AudioTrack.from_file "buffallo_soldiers.mp3"

Get a slice of a track, first 10 seconds

song = AudioTrack.from_file "mozart.mp3"
slice = song[10000] # rtrack works on milliseconds

Wonder how long is that song?

song = AudioTrack.from_file "jamming.mp3"
puts song.seconds

Repeat track 4 times

beat = AudioTrack.from_file "beat.wav"
remix = beat * 4

Save the result to disk

remix.export "remix.mp3", "mp3"
# or
remix.save "remix.mp3", "mp3"

Save the results with bitrate

remix.export "remix.mp3", "mp3", "192k"

Examples

Let's suppose you have plenty of mp4 videos that you'd like to convert to mp3 so you can listen on your mp3 player on the road.

require "rtrack"

Dir[Dir.home + "/Videos/*.mp4"].each do |video_path|
  video_name = File.basename(video_path, File.extname(video_path))
  puts "converting #{video_name}"
  song = AudioTrack.from_file video_path
  song.export "#{video_name}.mp3"
end

Dependencies

Requires ffmpeg or avconv for encoding and decoding.

ffmpeg (http://www.ffmpeg.org/)

-OR-

avconv (http://libav.org/)

Trivia

RTrack is inspired by pydub and jquery
As in pydub all AudioTrack objects are immutable
As in jquery you can chain operations using AudioTrack objects

Contributing

Fork it ( http://github.com/marcwebbie/rtrack/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request