Files

132 lines
4.6 KiB
JavaScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.audioFileToArray = exports.encodeWAV = exports.arrayBufferToBase64 = exports.minFramesForTargetMS = void 0;
function minFramesForTargetMS(targetDuration, frameSamples, sr = 16000) {
return Math.ceil((targetDuration * sr) / 1000 / frameSamples);
}
exports.minFramesForTargetMS = minFramesForTargetMS;
function arrayBufferToBase64(buffer) {
const bytes = new Uint8Array(buffer);
const len = bytes.byteLength;
const binary = new Array(len);
for (var i = 0; i < len; i++) {
const byte = bytes[i];
if (byte === undefined) {
break;
}
binary[i] = String.fromCharCode(byte);
}
return btoa(binary.join(""));
}
exports.arrayBufferToBase64 = arrayBufferToBase64;
/*
This rest of this was mostly copied from https://github.com/linto-ai/WebVoiceSDK
*/
function encodeWAV(samples, format = 3, sampleRate = 16000, numChannels = 1, bitDepth = 32) {
var bytesPerSample = bitDepth / 8;
var blockAlign = numChannels * bytesPerSample;
var buffer = new ArrayBuffer(44 + samples.length * bytesPerSample);
var view = new DataView(buffer);
/* RIFF identifier */
writeString(view, 0, "RIFF");
/* RIFF chunk length */
view.setUint32(4, 36 + samples.length * bytesPerSample, 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, format, true);
/* channel count */
view.setUint16(22, numChannels, true);
/* sample rate */
view.setUint32(24, sampleRate, true);
/* byte rate (sample rate * block align) */
view.setUint32(28, sampleRate * blockAlign, true);
/* block align (channel count * bytes per sample) */
view.setUint16(32, blockAlign, true);
/* bits per sample */
view.setUint16(34, bitDepth, true);
/* data chunk identifier */
writeString(view, 36, "data");
/* data chunk length */
view.setUint32(40, samples.length * bytesPerSample, true);
if (format === 1) {
// Raw PCM
floatTo16BitPCM(view, 44, samples);
}
else {
writeFloat32(view, 44, samples);
}
return buffer;
}
exports.encodeWAV = encodeWAV;
function interleave(inputL, inputR) {
var length = inputL.length + inputR.length;
var result = new Float32Array(length);
var index = 0;
var inputIndex = 0;
while (index < length) {
result[index++] = inputL[inputIndex];
result[index++] = inputR[inputIndex];
inputIndex++;
}
return result;
}
function writeFloat32(output, offset, input) {
for (var i = 0; i < input.length; i++, offset += 4) {
output.setFloat32(offset, input[i], true);
}
}
function floatTo16BitPCM(output, offset, input) {
for (var i = 0; i < input.length; i++, offset += 2) {
var s = Math.max(-1, Math.min(1, input[i]));
output.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7fff, true);
}
}
function writeString(view, offset, string) {
for (var i = 0; i < string.length; i++) {
view.setUint8(offset + i, string.charCodeAt(i));
}
}
async function audioFileToArray(audioFileData) {
const ctx = new OfflineAudioContext(1, 1, 44100);
const reader = new FileReader();
let audioBuffer = null;
await new Promise((res) => {
reader.addEventListener("loadend", (ev) => {
const audioData = reader.result;
ctx.decodeAudioData(audioData, (buffer) => {
audioBuffer = buffer;
ctx
.startRendering()
.then((renderedBuffer) => {
console.log("Rendering completed successfully");
res();
})
.catch((err) => {
console.error(`Rendering failed: ${err}`);
});
}, (e) => {
console.log(`Error with decoding audio data: ${e}`);
});
});
reader.readAsArrayBuffer(audioFileData);
});
if (audioBuffer === null) {
throw Error("some shit");
}
let _audioBuffer = audioBuffer;
let out = new Float32Array(_audioBuffer.length);
for (let i = 0; i < _audioBuffer.length; i++) {
for (let j = 0; j < _audioBuffer.numberOfChannels; j++) {
// @ts-ignore
out[i] += _audioBuffer.getChannelData(j)[i];
}
}
return { audio: out, sampleRate: _audioBuffer.sampleRate };
}
exports.audioFileToArray = audioFileToArray;
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