yomichan/ext/mixed/js/audio.js
2020-02-13 20:50:30 -05:00

185 lines
5.2 KiB
JavaScript

/*
* Copyright (C) 2019-2020 Alex Yatskov <alex@foosoft.net>
* Author: Alex Yatskov <alex@foosoft.net>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/*global apiAudioGetUrl*/
class TextToSpeechAudio {
constructor(text, voice) {
this.text = text;
this.voice = voice;
this._utterance = null;
this._volume = 1;
}
get currentTime() {
return 0;
}
set currentTime(value) {
// NOP
}
get volume() {
return this._volume;
}
set volume(value) {
this._volume = value;
if (this._utterance !== null) {
this._utterance.volume = value;
}
}
play() {
try {
if (this._utterance === null) {
this._utterance = new SpeechSynthesisUtterance(this.text || '');
this._utterance.lang = 'ja-JP';
this._utterance.volume = this._volume;
this._utterance.voice = this.voice;
}
speechSynthesis.cancel();
speechSynthesis.speak(this._utterance);
} catch (e) {
// NOP
}
}
pause() {
try {
speechSynthesis.cancel();
} catch (e) {
// NOP
}
}
static createFromUri(ttsUri) {
const m = /^tts:[^#?]*\?([^#]*)/.exec(ttsUri);
if (m === null) { return null; }
const searchParameters = {};
for (const group of m[1].split('&')) {
const sep = group.indexOf('=');
if (sep < 0) { continue; }
searchParameters[decodeURIComponent(group.substring(0, sep))] = decodeURIComponent(group.substring(sep + 1));
}
if (!searchParameters.text) { return null; }
const voice = audioGetTextToSpeechVoice(searchParameters.voice);
if (voice === null) { return null; }
return new TextToSpeechAudio(searchParameters.text, voice);
}
}
function audioGetFromUrl(url, willDownload) {
const tts = TextToSpeechAudio.createFromUri(url);
if (tts !== null) {
if (willDownload) {
throw new Error('AnkiConnect does not support downloading text-to-speech audio.');
}
return Promise.resolve(tts);
}
return new Promise((resolve, reject) => {
const audio = new Audio(url);
audio.addEventListener('loadeddata', () => {
if (audio.duration === 5.694694 || audio.duration === 5.720718) {
// Hardcoded values for invalid audio
reject(new Error('Could not retrieve audio'));
} else {
resolve(audio);
}
});
audio.addEventListener('error', () => reject(audio.error));
});
}
async function audioGetFromSources(expression, sources, optionsContext, willDownload, cache=null) {
const key = `${expression.expression}:${expression.reading}`;
if (cache !== null) {
const cacheValue = cache.get(expression);
if (typeof cacheValue !== 'undefined') {
return cacheValue;
}
}
for (let i = 0, ii = sources.length; i < ii; ++i) {
const source = sources[i];
const url = await apiAudioGetUrl(expression, source, optionsContext);
if (url === null) {
continue;
}
try {
let audio = await audioGetFromUrl(url, willDownload);
if (willDownload) {
// AnkiConnect handles downloading URLs into cards
audio = null;
}
const result = {audio, url, source};
if (cache !== null) {
cache.set(key, result);
}
return result;
} catch (e) {
// NOP
}
}
return {audio: null, url: null, source: null};
}
function audioGetTextToSpeechVoice(voiceURI) {
try {
for (const voice of speechSynthesis.getVoices()) {
if (voice.voiceURI === voiceURI) {
return voice;
}
}
} catch (e) {
// NOP
}
return null;
}
function audioPrepareTextToSpeech(options) {
if (
audioPrepareTextToSpeech.state ||
!options.audio.textToSpeechVoice ||
!(
options.audio.sources.includes('text-to-speech') ||
options.audio.sources.includes('text-to-speech-reading')
)
) {
// Text-to-speech not in use.
return;
}
// Chrome needs this value called once before it will become populated.
// The first call will return an empty list.
audioPrepareTextToSpeech.state = true;
try {
speechSynthesis.getVoices();
} catch (e) {
// NOP
}
}
audioPrepareTextToSpeech.state = false;