element-web/src/voice/compat.ts

79 lines
2.9 KiB
TypeScript
Raw Normal View History

/*
Copyright 2021 The Matrix.org Foundation C.I.C.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
import wavEncoderPath from 'opus-recorder/dist/waveWorker.min.js';
import decoderPath from 'opus-recorder/dist/decoderWorker.min.js';
import {SAMPLE_RATE} from "./VoiceRecording";
// @ts-ignore - we know that this is not a module. We're looking for a path.
import decoderWasmPath from 'opus-recorder/dist/decoderWorker.min.wasm';
export function createAudioContext(opts?: AudioContextOptions): AudioContext {
if (window.AudioContext) {
return new AudioContext(opts);
} else if (window.webkitAudioContext) {
return new window.webkitAudioContext(opts);
} else {
throw new Error("Unsupported browser");
}
}
export function decodeOgg(audioBuffer: ArrayBuffer): Promise<ArrayBuffer> {
// Condensed version of decoder example, using a promise:
// https://github.com/chris-rudmin/opus-recorder/blob/master/example/decoder.html
return new Promise((resolve) => { // no reject because the workers don't seem to have a fail path
console.log("Decoder WASM path: " + decoderWasmPath); // so we use the variable (avoid tree shake)
const typedArray = new Uint8Array(audioBuffer);
const decoderWorker = new Worker(decoderPath);
const wavWorker = new Worker(wavEncoderPath);
decoderWorker.postMessage({
command: 'init',
decoderSampleRate: SAMPLE_RATE,
outputBufferSampleRate: SAMPLE_RATE,
});
wavWorker.postMessage({
command: 'init',
wavBitDepth: 24, // standard for 48khz (SAMPLE_RATE)
wavSampleRate: SAMPLE_RATE,
});
decoderWorker.onmessage = (ev) => {
if (ev.data === null) { // null == done
wavWorker.postMessage({command: 'done'});
return;
}
wavWorker.postMessage({
command: 'encode',
buffers: ev.data,
}, ev.data.map(b => b.buffer));
};
wavWorker.onmessage = (ev) => {
if (ev.data.message === 'page') {
// The encoding comes through as a single page
resolve(new Blob([ev.data.page], {type: "audio/wav"}).arrayBuffer());
}
};
decoderWorker.postMessage({
command: 'decode',
pages: typedArray,
}, [typedArray.buffer]);
});
}