/* * 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/>. */ 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 } } } class AudioSystem { constructor({getAudioUri}) { this._cache = new Map(); this._cacheSizeMaximum = 32; this._getAudioUri = getAudioUri; if (typeof speechSynthesis !== 'undefined') { // speechSynthesis.getVoices() will not be populated unless some API call is made. speechSynthesis.addEventListener('voiceschanged', this._onVoicesChanged.bind(this)); } } async getDefinitionAudio(definition, sources, details) { const key = `${definition.expression}:${definition.reading}`; const cacheValue = this._cache.get(definition); if (typeof cacheValue !== 'undefined') { const {audio, uri, source} = cacheValue; return {audio, uri, source}; } for (const source of sources) { const uri = await this._getAudioUri(definition, source, details); if (uri === null) { continue; } try { const audio = await this._createAudio(uri, details); this._cacheCheck(); this._cache.set(key, {audio, uri, source}); return {audio, uri, source}; } catch (e) { // NOP } } throw new Error('Could not create audio'); } createTextToSpeechAudio({text, voiceUri}) { const voice = this._getTextToSpeechVoiceFromVoiceUri(voiceUri); if (voice === null) { throw new Error('Invalid text-to-speech voice'); } return new TextToSpeechAudio(text, voice); } _onVoicesChanged() { // NOP } async _createAudio(uri, details) { const ttsParameters = this._getTextToSpeechParameters(uri); if (ttsParameters !== null) { if (typeof details === 'object' && details !== null) { if (details.tts === false) { throw new Error('Text-to-speech not permitted'); } } return this.createTextToSpeechAudio(ttsParameters); } return await this._createAudioFromUrl(uri); } _createAudioFromUrl(url) { return new Promise((resolve, reject) => { const audio = new Audio(url); audio.addEventListener('loadeddata', () => { const duration = audio.duration; if (duration === 5.694694 || duration === 5.720718) { // Hardcoded values for invalid audio reject(new Error('Could not retrieve audio')); } else { resolve(audio); } }); audio.addEventListener('error', () => reject(audio.error)); }); } _getTextToSpeechVoiceFromVoiceUri(voiceUri) { try { for (const voice of speechSynthesis.getVoices()) { if (voice.voiceURI === voiceUri) { return voice; } } } catch (e) { // NOP } return null; } _getTextToSpeechParameters(uri) { const m = /^tts:[^#?]*\?([^#]*)/.exec(uri); if (m === null) { return null; } const searchParameters = new URLSearchParams(m[1]); const text = searchParameters.get('text'); const voiceUri = searchParameters.get('voice'); return (text !== null && voiceUri !== null ? {text, voiceUri} : null); } _cacheCheck() { const removeCount = this._cache.size - this._cacheSizeMaximum; if (removeCount <= 0) { return; } const removeKeys = []; for (const key of this._cache.keys()) { removeKeys.push(key); if (removeKeys.length >= removeCount) { break; } } for (const key of removeKeys) { this._cache.delete(key); } } }