Waveforms


`new Waveforms(worker?, cache?)`	Peaks from the cache, or worked out and cached
`waveforms.get(key, audio)`	`audio` is called only when `key` isn't cached; may return a promise
`waveforms.cached(key)`	Cached peaks or `null`, without computing any
`waveforms.destroy()`	Stop the worker
`new PeaksWorker(samplesPerPeak = 64)`	`compute(audio)` returns `Peaks`
`new PeaksCache(name?, maxInMemory = 64)`	A `PeaksStore` in memory and Cache Storage
`peaksOf(channels, sampleRate, samplesPerPeak?)`	Peaks on the current thread
`peakAt(peaks, from, to)`	`[min, max]` between two times, from -1 to 1
`encodePeaks(peaks)` / `decodePeaks(buffer)`	Peaks to bytes and back
`drawWaveform(canvas, options)`	Draw part of a clip's waveform yourself

audio is anything shaped like an AudioBuffer: sampleRate, numberOfChannels and getChannelData(channel).

interface Peaks {
  sampleRate: number;
  length: number; // samples
  levels: { samplesPerPeak: number; data: Int16Array }[]; // finest first
}

interface PeaksStore {
  get(key: string): Promise<Peaks | null>;
  put(key: string, peaks: Peaks): Promise<void>;
  clear(): Promise<void>;
}

Waveforms ​

Waveforms