aboutsummaryrefslogtreecommitdiff
path: root/ext/mixed/js/audio-system.js
blob: 3273f9822bf3f29eb72e6031ae4d505af676ef16 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
/*
 * Copyright (C) 2019-2020  Yomichan Authors
 *
 * 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;
        }
    }

    async 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({audioUriBuilder, useCache}) {
        this._cache = useCache ? new Map() : null;
        this._cacheSizeMaximum = 32;
        this._audioUriBuilder = audioUriBuilder;

        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 hasCache = (this._cache !== null);

        if (hasCache) {
            const cacheValue = this._cache.get(key);
            if (typeof cacheValue !== 'undefined') {
                const {audio, uri, source} = cacheValue;
                const index = sources.indexOf(source);
                if (index >= 0) {
                    return {audio, uri, index};
                }
            }
        }

        for (let i = 0, ii = sources.length; i < ii; ++i) {
            const source = sources[i];
            const uri = await this._getAudioUri(definition, source, details);
            if (uri === null) { continue; }

            try {
                const audio = await this._createAudio(uri);
                if (hasCache) {
                    this._cacheCheck();
                    this._cache.set(key, {audio, uri, source});
                }
                return {audio, uri, index: i};
            } 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) {
        const ttsParameters = this._getTextToSpeechParameters(uri);
        if (ttsParameters !== null) {
            const {text, voiceUri} = ttsParameters;
            return this.createTextToSpeechAudio(text, voiceUri);
        }

        return await this._createAudioFromUrl(uri);
    }

    _getAudioUri(definition, source, details) {
        return (
            this._audioUriBuilder !== null ?
            this._audioUriBuilder.getUri(definition, source, details) :
            null
        );
    }

    _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);
        }
    }
}