Working with the Web Audio API

✍ Scribed by Joshua Reiss

• Year: 2022
• Tongue: English
• Leaves: 325
• Category: Library

✦ Table of Contents

Half-Title Page
Series Page
Title Page
Copyright Page
Table of Contents
List of Figures
List of Code Examples
Resources
Preface
Acknowledgments
1 Introducing the Web Audio API
The Web Audio API
The audio context
What you need to get started
Example: Hello World
Example: – adding user interaction
Interlude – Generating sound with scheduled sources
2 Oscillators
A bit of theory
OscillatorNode
Parameters
The oscillator types
Example: basic use of the OscillatorNode
The PeriodicWave
Square wave example
Pulse wave example
The detune parameter
Example: detuning an oscillator
Note
3 Audio buffer sources
The AudioBuffer
Example: creating a buffer source
The AudioBufferSourceNode
How does playback work?
Example: varying playback of an audio buffer
Example: wavetable synthesis with audio buffers
Example: pausing audio
Example: playing audio backwards
4 The constant source node
Introducing the constant source
Example: DC offset with a ConstantSourceNode
Example: using a ConstantSourceNode to affect many parameters
Example: grouping audio
Interlude – Audio parameters
5 Scheduling and setting parameters
Audio parameters
Changing audio parameters
Methods
setValueAtTime(value, startTime)
linearRampToValueAtTime(value, endTime)
exponentialRampToValueAtTime(value, endTime)
setTargetAtTime(target, startTime, timeConstant)
setValueCurveAtTime(values, startTime, duration)
cancelScheduledValues(cancelTime)
cancelAndHoldAtTime(cancelTime)
Computation of value
Example: beep sound with parameter automation
Example: beep sound with custom automation
Example: repeating a beep
Example: crossfade
Example: synthesising a bell sound
6 Connecting audio parameters and modulation
Connections revisited
Disconnecting nodes
Connecting audio parameters
Example: FM synthesis
Example: AM synthesis
Tremolo and vibrato
Ring modulation
Interlude – Destination and source nodes
7 Analysis and visualization
AnalyserNode
FFT windowing and smoothing over time
Using the AnalyserNode
Example: visualizing sound
8 Loading, playing and recording
Working with media elements
Example: use of an