cs-weekly-2-material-audio-player

Implements Web Audio API to create a simple wave oscillator visualizer. Original designed classes and architecture heavily inspired by examples on MDN. See MDN example

Writeup

I wrote a blog article discussing the Web Audio API and explaining the program here.

This project is an iteration of an effort called Code Something Weekly. The article explaining how and why is found here

Demo

LIVE DEMO

AudioPlayer

Kind: global class

• AudioPlayer
  • new AudioPlayer(opts)
  • .changeGain(volume) ⇒ undefined
  • .changeFrequency(f, df) ⇒ undefined
  • .getAnalyzerBinCount(f) ⇒ number
  • .getAnalyzerFFTSize(f) ⇒ number
  • .getAnalyzerTimeBytes(f, dataArray) ⇒ undefined
  • .togglePlay() ⇒ undefined

new AudioPlayer(opts)

Param	Type	Default	Description
opts	Object		(required)
opts.ctx	Object		(required) The AudioContext Object
[opts.volume]	number	0.5	the overall volume
[opts.f1]	number	130.81	the frequency of wave 1
[opts.f2]	number	164.81	the frequency of wave 2
[opts.f3]	number	196.00	the frequency of wave 3

audioPlayer.changeGain(volume) ⇒ undefined

Adjusts the overall volume

Kind: instance method of AudioPlayer

Param	Type	Description
volume	number	between (0.0, 1.0)

audioPlayer.changeFrequency(f, df) ⇒ undefined

Adjusts the value of a frequency.

Kind: instance method of AudioPlayer

Param	Type	Description
f	number	(1, 3). The frequency to change.
df	number	the amount to change the frequency

audioPlayer.getAnalyzerBinCount(f) ⇒ number

Returns 1/2 the FFT value for a given source. Represents the number of data values for visualization in the frequency domain. Use to assign the length of an unsigned 8-bit array (ie: Uint8Array [binCount])

Kind: instance method of AudioPlayer

Param	Type	Description
f	number	The frequency (1, 3) to obtain the bin count

audioPlayer.getAnalyzerFFTSize(f) ⇒ number

Returns the fftSize which is an unsigned long value and represents the window size in samples that is used when performing a Fast Fourier Transform.

Kind: instance method of AudioPlayer
Returns: number - - an unsigned long

Param	Type	Description
f	number	The frequency (1, 3) for which to get the FFT size.

audioPlayer.getAnalyzerTimeBytes(f, dataArray) ⇒ undefined

Copies the current time domain data into the provided array. Must be of type Uint8Array.

Kind: instance method of AudioPlayer

Param	Type	Description
f	number	The frequency (1, 3) to get the time btyes
dataArray	Uint8Array

audioPlayer.togglePlay() ⇒ undefined

Starts or stops the audio player.

Kind: instance method of AudioPlayer