DynamicsCompressorNode.reduction polyfill

polyfill-dynamicscompressor-reduction.js

!function() {

  var _isCompressorReductionAudioParam = 
    typeof (new OfflineAudioContext(1, 1, 44100)).createDynamicsCompressor().reduction 
    === 'object';

  AudioContext.prototype._createDynamicsCompressor =
    AudioContext.prototype.createDynamicsCompressor;
  OfflineAudioContext.prototype._createDynamicsCompressor =
    OfflineAudioContext.prototype.createDynamicsCompressor;

  AudioContext.prototype.createDynamicsCompressor =
  OfflineAudioContext.prototype.createDynamicsCompressor = function () {
    var compressor = this._createDynamicsCompressor();
    if (_isCompressorReductionAudioParam) {
      compressor._reduction = compressor.reduction;
      Object.defineProperty(compressor, 'reduction', {
        get: function () {
          return compressor._reduction.value;
        }
      });
    }
    return compressor;
  };

}();