support deepgram

lib/synth-audio.js

@@ -84,7 +84,7 @@ async function synthAudio(client, logger, stats, { account_sid,
   logger = logger || noopLogger;
 
   assert.ok(['google', 'aws', 'polly', 'microsoft',
-    'wellsaid', 'nuance', 'nvidia', 'ibm', 'elevenlabs', 'whisper'].includes(vendor) ||
+    'wellsaid', 'nuance', 'nvidia', 'ibm', 'elevenlabs', 'whisper', 'deepgram'].includes(vendor) ||
   vendor.startsWith('custom'),
   `synthAudio supported vendors are google, aws, microsoft, nuance, nvidia and wellsaid, not ${vendor}`);
   if ('google' === vendor) {
@@ -199,6 +199,9 @@ async function synthAudio(client, logger, stats, { account_sid,
       case 'whisper':
         audioBuffer = await synthWhisper(logger, {credentials, stats, voice, text});
         break;
+      case 'deepgram':
+        audioBuffer = await synthDeepgram(logger, {credentials, stats, model, text});
+        break;
       case vendor.startsWith('custom') ? vendor : 'cant_match_value':
         ({ audioBuffer, filePath } = await synthCustomVendor(logger,
           {credentials, stats, language, voice, text, filePath}));
@@ -640,8 +643,27 @@ const synthWhisper = async(logger, {credentials, stats, voice, text}) => {
     stats.increment('tts.count', ['vendor:openai', 'accepted:no']);
     throw err;
   }
-}
-;
+};
+
+const synthDeepgram = async(logger, {credentials, stats, model, text}) => {
+  const {api_key} = credentials;
+  try {
+    const post = bent('https://api.beta.deepgram.com', 'POST', 'buffer', {
+      'Authorization': `Token ${api_key}`,
+      'Accept': 'audio/mpeg',
+      'Content-Type': 'application/json'
+    });
+    const mp3 = await post(`/v1/speak?model=${model}`, {
+      text
+    });
+    return mp3;
+  } catch (err) {
+    logger.info({err}, 'synth Deepgram returned error');
+    stats.increment('tts.count', ['vendor:deepgram', 'accepted:no']);
+    throw err;
+  }
+};
+
 const getFileExtFromMime = (mime) => {
   switch (mime) {
     case 'audio/wav':