Zappa

Zappa is a high level audio manipulation library for Ruby, inspired by pydub.

Installation

First install ffmpeg:

brew install ffmpeg

Add this line to your application's Gemfile:

gem 'zappa'

And then execute:

$ bundle

Or install it yourself as:

$ gem install zappa

Usage

At the core of Zappa is the Clip, an immutable audio unit.

Importing

Import a wav file into a clip:

require 'zappa'
    
clip = Zappa::Clip.new
clip.from_file('this_is_a_song.wav')

The clip will create a safe copy of the wav before you can edit it. Remember, clips are immutable so any destructive operations return a new clip.

Generators

Alternatively, you can generate your own sounds from scratch:

generator = Zappa::Generator.new
clip = generator.generate('sine', 1000, 1)

This will create a 1000 Hz sine wave that is 1 second long.

Editing Clips

You can slice clips into smaller chunks:

slice_a = clip.slice(0, 1000)    # clip containing 1st second
slice_b = clip.slice(1000, 2000) # clip containing 3rd second

You can also join clips:

joined_clip = slice_a + slice_b  # clip containing 1st and 3rd seconds

Signal Processing

Amplify or attenuate clips with the following syntax:

louder_clip = joined_clip + 2
louder_clip = joined_clip.amplify(2)

Export

Once you're done editing a clip, you can export it:

louder_clip.export('output.wav')

That's it for now. DSP tools are coming soon!

Contributing

1. Fork it ( https://github.com/[my-github-username]/zappa/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request