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// Adapted from https://www.npmjs.com/package/audiobuffer-to-wav
export function encodeWAV(samples) {
let offset = 44;
const buffer = new ArrayBuffer(offset + samples.length * 4);
const view = new DataView(buffer);
const sampleRate = 16000;
/* RIFF identifier */
writeString(view, 0, 'RIFF')
/* RIFF chunk length */
view.setUint32(4, 36 + samples.length * 4, true)
/* RIFF type */
writeString(view, 8, 'WAVE')
/* format chunk identifier */
writeString(view, 12, 'fmt ')
/* format chunk length */
view.setUint32(16, 16, true)
/* sample format (raw) */
view.setUint16(20, 3, true)
/* channel count */
view.setUint16(22, 1, true)
/* sample rate */
view.setUint32(24, sampleRate, true)
/* byte rate (sample rate * block align) */
view.setUint32(28, sampleRate * 4, true)
/* block align (channel count * bytes per sample) */
view.setUint16(32, 4, true)
/* bits per sample */
view.setUint16(34, 32, true)
/* data chunk identifier */
writeString(view, 36, 'data')
/* data chunk length */
view.setUint32(40, samples.length * 4, true)
for (let i = 0; i < samples.length; ++i, offset += 4) {
view.setFloat32(offset, samples[i], true)
}
return buffer
}
function writeString(view, offset, string) {
for (let i = 0; i < string.length; ++i) {
view.setUint8(offset + i, string.charCodeAt(i))
}
}
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