Browser-Waveform

From Gun.io

Client-side waveform rendering of an audio track in pure JavaScript.

Currently works in Chrome through the 'webkitAudioContext' object.

Firefox only has their own useless nonstandard sound API thing that makes Flash look good.

Coffee to JavaScript

• npm install -g coffee-script
• coffee --compile chrome-waveform.coffee

Notes

For local testing, remember to run Chrome locally with --allow-file-access-from-files.

• OSX: open /Applications/Google\ Chrome.app --args --allow-file-access-from-files

Example

• See waveform.html

Schema

Waveform :: ({file, canvas, onStatus, onReady}) -> {
  playback :: { moveCursor :: (Num) -> () }
  view :: {
    play     :: -> ()
    playAt   :: (Num) -> ()
    getTime  :: -> Num
    pause    :: -> ()
    isPaused :: -> Bool
  }
}