web audio seminar.js

talked about javascript, functions/passing functions, objects, classes, async/callbacks


audio as a pipeline

source is audio data generater or loaded
oscillator, mp3, mic

destination is output
laptop speakers, ScriptProcessorNode

context = new AudioContext()
context.currentTime
context.destination
script processer more complicated, to be talked about later

Web MIDI API to e.g. use keyboard information

osc = context.createOscillator() // generates a tone
gain = context.createGain() // sets volume
buf = context.CreateBuffer() // in-memory audio data
bfil = context.CreateBiquadFilter() // simple low-pass filter (remove bass)
context.destination // audio destination
etc.., use console

join pieces of pipeline (nodes) with the connect method

Common pipeline:
Source -> Dest
2nd most common
Source -> GainNode -> Dest

context = new AudioContext()
osc  = c.createOscillator()
osc.frequency.value = 440
osc.connect(c.destination)
osc.start(0)
osc.stop()

use xhr for mic
filters choose parts of freq spectrum
filters can be used for certain noise types
AudioPannerNode mixing to change pan (L/R) 
Crossfading

context = new AudioContext()
osc  = c.createOscillator()
gain = context.createGain()
osc.frequency.value = 440
osc.connect(gain)
gain.gain.value = 0.6

buffer-loader library
play song
  bufferLoad = new BufferLoader(
    context,
    [
      '../song.mp3'
      ],
      finishedLoading
    );
    
  bufferLoader.load()
func stop song
  
  
context.createBufferSource
source.buffer = bufferList[0]
source.connext(context.destination);
source.start(0);

hughzabriskie.com/sequencer // can probs copy his js code there
add piano(g4) on 1 2 // midi notes
d generator(piano, Amaj something)
add piano(b2,e3,gs3) on 1 // three notes on b3
add dry-kick someth
add ride-2 every 16th gain(0.6)