Add azure tts

tts/azure/index.js

@@ -0,0 +1,58 @@
+const BaseEngine = require('../BaseEngine');
+const sdk = require("microsoft-cognitiveservices-speech-sdk");
+const fetch = require('node-fetch');
+
+module.exports = class AzureTTS extends BaseEngine {
+    constructor() {
+        super("azure", "Microsoft Azure TTS", "wav");
+        this.voices = {};
+        this.populateVoiceList();
+    }
+
+    getDefaultVoice() {
+        return "";
+    }
+
+    getSpeechFile(text, filepath, voice = this.getDefaultVoice(), params = {}) {
+        return new Promise((resolve, reject) => {
+            const speechConfig = sdk.SpeechConfig.fromSubscription(process.env.AZURE_API_KEY, process.env.AZURE_REGION);
+            speechConfig.speechSynthesisOutputFormat = sdk.SpeechSynthesisOutputFormat.Riff24Khz16BitMonoPcm;
+            speechConfig.speechSynthesisVoiceName = this.voices[voice];
+            const audioConfig = sdk.AudioConfig.fromAudioFileOutput(filepath);
+            const synthesizer = new sdk.SpeechSynthesizer(speechConfig, audioConfig);
+            synthesizer.speakTextAsync(
+                text,
+                result => {
+                    synthesizer.close();
+                    if (result) {
+                        // return result as stream
+                        resolve(filepath);
+                    }
+                },
+                error => {
+                    console.log(error);
+                    synthesizer.close();
+                    reject(error);
+                });
+        })
+    }
+
+    async populateVoiceList() {
+        const opts = {
+            headers: {
+                'Ocp-Apim-Subscription-Key': process.env.AZURE_API_KEY
+            }
+        }
+        const res = await fetch(process.env.AZURE_LIST_ENDPOINT, opts);
+        const json = await res.json();
+        json.forEach((voice) => {
+            if (this.voices[voice.DisplayName]) {
+                if (voice.Name.includes('Neural')) {
+                    this.voices[voice.DisplayName] = voice.ShortName;
+                }
+            } else {
+                this.voices[voice.DisplayName] = voice.ShortName;
+            }
+        });
+    }
+}