summaryrefslogtreecommitdiff
path: root/ext/mixed/js/audio-system.js
blob: 4a49c1350cc27675f17f40b28d5242d0ce7f1bc0 (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
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 * 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, requestBuilder=null, useCache}) {
        this._cache = useCache ? new Map() : null;
        this._cacheSizeMaximum = 32;
        this._audioUriBuilder = audioUriBuilder;
        this._requestBuilder = requestBuilder;

        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(sources, expression, reading, details) {
        const key = `${expression}:${reading}`;
        const hasCache = (this._cache !== null && !details.disableCache);

        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(source, expression, reading, details);
            if (uri === null) { continue; }

            try {
                const audio = (
                    details.binary ?
                    await this._createAudioBinary(uri) :
                    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
    }

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

    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);
    }

    async _createAudioBinary(uri) {
        const ttsParameters = this._getTextToSpeechParameters(uri);
        if (ttsParameters !== null) {
            throw new Error('Cannot create audio from text-to-speech');
        }

        return await this._createAudioBinaryFromUrl(uri);
    }

    _createAudioFromUrl(url) {
        return new Promise((resolve, reject) => {
            const audio = new Audio(url);
            audio.addEventListener('loadeddata', () => {
                if (!this._isAudioValid(audio)) {
                    reject(new Error('Could not retrieve audio'));
                } else {
                    resolve(audio);
                }
            });
            audio.addEventListener('error', () => reject(audio.error));
        });
    }

    async _createAudioBinaryFromUrl(url) {
        const response = await this._requestBuilder.fetchAnonymous(url, {
            method: 'GET',
            mode: 'cors',
            cache: 'default',
            credentials: 'omit',
            redirect: 'follow',
            referrerPolicy: 'no-referrer'
        });
        const arrayBuffer = await response.arrayBuffer();

        if (!await this._isAudioBinaryValid(arrayBuffer)) {
            throw new Error('Could not retrieve audio');
        }

        return this._arrayBufferToBase64(arrayBuffer);
    }

    _arrayBufferToBase64(arrayBuffer) {
        return btoa(String.fromCharCode(...new Uint8Array(arrayBuffer)));
    }

    _isAudioValid(audio) {
        const duration = audio.duration;
        return (
            duration !== 5.694694 && // jpod101 invalid audio (Chrome)
            duration !== 5.720718 // jpod101 invalid audio (Firefox)
        );
    }

    async _isAudioBinaryValid(arrayBuffer) {
        const digest = await AudioSystem.arrayBufferDigest(arrayBuffer);
        switch (digest) {
            case 'ae6398b5a27bc8c0a771df6c907ade794be15518174773c58c7c7ddd17098906': // jpod101 invalid audio
                return false;
            default:
                return true;
        }
    }

    _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);
        }
    }

    static async arrayBufferDigest(arrayBuffer) {
        const hash = new Uint8Array(await crypto.subtle.digest('SHA-256', new Uint8Array(arrayBuffer)));
        let digest = '';
        for (const byte of hash) {
            digest += byte.toString(16).padStart(2, '0');
        }
        return digest;
    }
}