understanding getByteTimeDomainData and getByteFrequencyData in web audio

Question

The documentation for both of these methods are both very generic wherever I look. I would like to know what exactly I\'m looking at with the returned arrays I\'m getting fr

Answer 1

Mozilla 's documentation describes the difference between getFloatTimeDomainData and getFloatFrequencyData, which I summarize below. Mozilla docs reference the Web Audio experiment ; the voice-change-o-matic. The voice-change-o-matic illustrates the conceptual difference to me (it only works in my Firefox; it does not work in my Chrome).

TimeDomain

• TimeDomain functions are over some span of time.
• We often visualize TimeDomain data using oscilloscopes.
• In other words, we visualize TimeDomain data with a line chart, where the x-axis is time, and the y axis is a measure of a signal.
• Change the voice-change-o-matic "visualizer setting" to sinewave to see getFloatTimeDomainData(...)

Frequency

• Frequency functions (GetByteFrequencyData) are at a point in time.
• We sometimes see these in mp3 players/ winamp-style music players (aka "equalizer' visualizations).
• In other words, we visualize Frequency data with a bar graph, where the x-axis are frequency bands, and the y-axis is the strength of each frequency band
• Change the voice-change-o-matic "visualizer setting" to frequency bars to see getFloatFrequencyData(...)