function isConstantValueOf(channelData, value) {
  var mismatches = {};
  for (var i = 0; i < channelData.length; i++) {
      if (channelData[i] !== value)
      mismatches[i] = channelData[i];
  }

  return Object.keys(mismatches).length === 0;
}
Check if the array is filled with the specified value only.
@param  {Float32Array} channelData The target array for testing.
@param  {Number} value             A value for the testing.
@return {Boolean}