Paperclip Waveform is a Paperclip post-processor. It generates a png file with the waveform from an audio attachment, using the fantastic waveform gem github.com/benalavi/waveform
Waveform depends on ruby-audio, which in turn depends on libsndfile.
Build libsndfile from (www.mega-nerd.com/libsndfile/), install it via apt:
sudo apt-get install libsndfile1-dev
libsndfile in macports, etc…
ffmpeg is also required to convert original files to WAV
sudo apt-get install ffmpeg
Then add the gem to your Gemfile:
gem 'paperclip_waveform'
And the style to your audio:
class Audio < ActiveRecord::Base has_attached_file :file, styles: { waveform: { format: :png, convert_options: { color: :transparent } } }, processors: [ :waveform ]
Take a look at github.com/benalavi/waveform/blob/master/bin/waveform for available options