Create new AudioSystem class

This commit is contained in:
toasted-nutbread 2020-03-07 12:44:14 -05:00
parent b8eb5e6016
commit 110e561eae

View File

@ -83,6 +83,124 @@ class TextToSpeechAudio {
} }
} }
class AudioSystem {
constructor() {
this._cache = new Map();
this._cacheSizeMaximum = 32;
if (typeof speechSynthesis !== 'undefined') {
// speechSynthesis.getVoices() will not be populated unless some API call is made.
speechSynthesis.addEventListener('voiceschanged', this._onVoicesChanged.bind(this));
}
}
async getExpressionAudio(expression, sources, optionsContext, details) {
const key = `${expression.expression}:${expression.reading}`;
const cacheValue = this._cache.get(expression);
if (typeof cacheValue !== 'undefined') {
const {audio, uri, source} = cacheValue;
return {audio, uri, source};
}
for (const source of sources) {
const uri = await apiAudioGetUrl(expression, source, optionsContext);
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);
}
}
}
function audioGetFromUrl(url, willDownload) { function audioGetFromUrl(url, willDownload) {
const tts = TextToSpeechAudio.createFromUri(url); const tts = TextToSpeechAudio.createFromUri(url);
if (tts !== null) { if (tts !== null) {