fix

lib/session/call-session.js

@@ -180,6 +180,13 @@ class CallSession extends Emitter {
     this.application.speech_synthesis_vendor = vendor;
   }
 
+  get fallbackSpeechSynthesisVendor() {
+    return this.application.use_for_fallback_speech ? this.application.fallback_speech_synthesis_vendor : null;
+  }
+  set fallbackSpeechSynthesisVendor(vendor) {
+    this.application.fallback_speech_synthesis_vendor = vendor;
+  }
+
   /**
    * default label to use for speech synthesis if not provided in the app
    */
@@ -189,6 +196,13 @@ class CallSession extends Emitter {
   set speechSynthesisLabel(label) {
     this.application.speech_synthesis_label = label;
   }
+
+  get fallbackSpeechSynthesisLabel() {
+    return this.application.fallback_speech_synthesis_label;
+  }
+  set fallbackSpeechSynthesisLabel(label) {
+    this.application.fallback_speech_synthesis_label = label;
+  }
   /**
    * default voice to use for speech synthesis if not provided in the app
    */
@@ -198,6 +212,13 @@ class CallSession extends Emitter {
   set speechSynthesisVoice(voice) {
     this.application.speech_synthesis_voice = voice;
   }
+
+  get fallbackSpeechSynthesisVoice() {
+    return this.application.fallback_speech_synthesis_voice;
+  }
+  set fallbackSpeechSynthesisVoice(voice) {
+    this.application.fallback_speech_synthesis_voice = voice;
+  }
   /**
    * default language to use for speech synthesis if not provided in the app
    */
@@ -208,6 +229,13 @@ class CallSession extends Emitter {
     this.application.speech_synthesis_language = language;
   }
 
+  get fallbackSpeechSynthesisLanguage() {
+    return this.application.fallback_speech_synthesis_language;
+  }
+  set fallbackSpeechSynthesisLanguage(language) {
+    this.application.fallback_speech_synthesis_language = language;
+  }
+
   /**
    * default vendor to use for speech recognition if not provided in the app
    */
@@ -217,6 +245,13 @@ class CallSession extends Emitter {
   set speechRecognizerVendor(vendor) {
     this.application.speech_recognizer_vendor = vendor;
   }
+
+  get fallbackSpeechRecognizerVendor() {
+    return this.application.fallback_speech_recognizer_vendor;
+  }
+  set fallbackSpeechRecognizerVendor(vendor) {
+    this.application.fallback_speech_recognizer_vendor = vendor;
+  }
   /**
    * default vendor to use for speech recognition if not provided in the app
    */
@@ -226,6 +261,13 @@ class CallSession extends Emitter {
   set speechRecognizerLabel(label) {
     this.application.speech_recognizer_label = label;
   }
+
+  get fallbackSpeechRecognizerLabel() {
+    return this.application.fallback_speech_recognizer_label;
+  }
+  set fallbackSpeechRecognizerLabel(label) {
+    this.application.fallback_speech_recognizer_label = label;
+  }
   /**
  * default language to use for speech recognition if not provided in the app
  */
@@ -236,6 +278,13 @@ class CallSession extends Emitter {
     this.application.speech_recognizer_language = language;
   }
 
+  get fallbackSpeechRecognizerLanguage() {
+    return this.application.fallback_speech_recognizer_language;
+  }
+  set fallbackSpeechRecognizerLanguage(language) {
+    this.application.fallback_speech_recognizer_language = language;
+  }
+
   /**
    * indicates whether the call currently in progress
    */

lib/tasks/config.js

@@ -114,6 +114,19 @@ class TaskConfig extends Task {
       cs.speechSynthesisVoice = this.synthesizer.voice !== 'default'
         ? this.synthesizer.voice
         : cs.speechSynthesisVoice;
+      // fallback vendor
+      cs.fallbackSpeechSynthesisVendor = this.synthesizer.fallbackVendor !== 'default'
+        ? this.synthesizer.fallbackVendor
+        : cs.fallbackSpeechSynthesisVendor;
+      cs.fallbackSpeechSynthesisLabel = this.synthesizer.fallbackLabel !== 'default'
+        ? this.synthesizer.fallbackLabel
+        : cs.fallbackSpeechSynthesisLabel;
+      cs.fallbackSpeechSynthesisLanguage = this.synthesizer.fallbackLanguage !== 'default'
+        ?  this.synthesizer.fallbackLanguage
+        : cs.fallbackSpeechSynthesisLanguage;
+      cs.fallbackSpeechSynthesisVoice = this.synthesizer.fallbackVoice !== 'default'
+        ? this.synthesizer.fallbackVoice
+        : cs.fallbackSpeechSynthesisVoice;
       this.logger.info({synthesizer: this.synthesizer}, 'Config: updated synthesizer');
     }
     if (this.hasRecognizer) {
@@ -126,6 +139,17 @@ class TaskConfig extends Task {
       cs.speechRecognizerLanguage = this.recognizer.language !== 'default'
         ? this.recognizer.language
         : cs.speechRecognizerLanguage;
+
+      //fallback
+      cs.fallbackSpeechRecognizerVendor = this.recognizer.fallbackVendor !== 'default'
+        ? this.recognizer.fallbackVendor
+        : cs.fallbackSpeechRecognizerVendor;
+      cs.fallbackSpeechRecognizerLabel = this.recognizer.fallbackLabel !== 'default'
+        ? this.recognizer.fallbackLabel
+        : cs.fallbackSpeechRecognizerLabel;
+      cs.fallbackSpeechRecognizerLanguage = this.recognizer.fallbackLanguage !== 'default'
+        ? this.recognizer.fallbackLanguage
+        : cs.fallbackSpeechRecognizerLanguage;
       cs.isContinuousAsr = typeof this.recognizer.asrTimeout === 'number' ? true : false;
       if (cs.isContinuousAsr) {
         cs.asrTimeout = this.recognizer.asrTimeout;

lib/tasks/dialogflow/index.js

@@ -59,6 +59,12 @@ class Dialogflow extends Task {
       this.language = this.data.tts.language || 'default';
       this.voice = this.data.tts.voice || 'default';
       this.speechSynthesisLabel = this.data.tts.label || null;
+
+      // fallback tts
+      this.fallbackVendor = this.data.tts.fallbackVendor || 'default';
+      this.fallbackLanguage = this.data.tts.fallbackLanguage || 'default';
+      this.fallbackVoice = this.data.tts.fallbackLanguage || 'default';
+      this.fallbackLabel = this.data.tts.fallbackLabel || 'default';
     }
     this.bargein = this.data.bargein;
   }
@@ -119,9 +125,15 @@ class Dialogflow extends Task {
         this.vendor = cs.speechSynthesisVendor;
         this.language = cs.speechSynthesisLanguage;
         this.voice = cs.speechSynthesisVoice;
+        this.speechSynthesisLabel = cs.speechSynthesisLabel;
       }
-      this.ttsCredentials = cs.getSpeechCredentials(this.vendor, 'tts',
-        this.speechSynthesisLabel || cs.speechSynthesisLabel);
+      if (this.fallbackVendor === 'default') {
+        this.fallbackVendor = cs.fallbackSpeechSynthesisVendor;
+        this.fallbackLanguage = cs.fallbackSpeechSynthesisLanguage;
+        this.fallbackVoice = cs.fallbackSpeechSynthesisVoice;
+        this.fallbackLabel = cs.fallbackSpeechSynthesisLabel;
+      }
+      this.ttsCredentials = cs.getSpeechCredentials(this.vendor, 'tts', this.speechSynthesisLabel);
 
       this.ep.addCustomEventListener('dialogflow::intent', this._onIntent.bind(this, ep, cs));
       this.ep.addCustomEventListener('dialogflow::transcription', this._onTranscription.bind(this, ep, cs));
@@ -223,17 +235,7 @@ class Dialogflow extends Task {
       }
 
       try {
-        const obj = {
-          account_sid: cs.accountSid,
-          text: intent.fulfillmentText,
-          vendor: this.vendor,
-          language: this.language,
-          voice: this.voice,
-          salt: cs.callSid,
-          credentials: this.ttsCredentials
-        };
-        this.logger.debug({obj}, 'Dialogflow:_onIntent - playing message via tts');
-        const {filePath, servedFromCache} = await synthAudio(stats, obj);
+        const {filePath, servedFromCache} = await this.fallbackSynthAudio(cs, intent, stats, synthAudio);
         if (filePath) cs.trackTmpFile(filePath);
         if (!this.ttsCredentials && !servedFromCache) cs.billForTts(intent.fulfillmentText.length);
 
@@ -279,6 +281,46 @@ class Dialogflow extends Task {
     }
   }
 
+  async fallbackSynthAudio(cs, intent, stats, synthAudio) {
+    try {
+      const obj = {
+        account_sid: cs.accountSid,
+        text: intent.fulfillmentText,
+        vendor: this.vendor,
+        language: this.language,
+        voice: this.voice,
+        salt: cs.callSid,
+        credentials: this.ttsCredentials
+      };
+      this.logger.debug({obj}, 'Dialogflow:_onIntent - playing message via tts');
+
+      return await synthAudio(stats, obj);
+    } catch (error) {
+      this.logger.info({error}, 'Failed to synthesize audio from primary vendor');
+
+      try {
+        if (this.fallbackVendor) {
+          const credentials = cs.getSpeechCredentials(this.fallbackVendor, 'tts', this.fallbackLabel);
+          const obj = {
+            account_sid: cs.accountSid,
+            text: intent.fulfillmentText,
+            vendor: this.fallbackVendor,
+            language: this.fallbackLanguage,
+            voice: this.fallbackVoice,
+            salt: cs.callSid,
+            credentials
+          };
+          this.logger.debug({obj}, 'Dialogflow:_onIntent - playing message via fallback tts');
+          return await synthAudio(stats, obj);
+        }
+      } catch (err) {
+        this.logger.info({err}, 'Failed to synthesize audio from falllback vendor');
+        throw err;
+      }
+      throw error;
+    }
+  }
+
   /**
    * A transcription - either interim or final - has been returned.
    * If we are doing barge-in based on hotword detection, check for the hotword or phrase.

lib/tasks/gather.js

@@ -65,6 +65,11 @@ class TaskGather extends Task {
       const recognizer = this.data.recognizer;
       this.vendor = recognizer.vendor;
       this.language = recognizer.language;
+      this.label = recognizer.label;
+
+      this.fallbackVendor = recognizer.fallbackVendor || 'default';
+      this.fallbackLanguage = recognizer.fallbackLanguage || 'default';
+      this.fallbackLabel = recognizer.fallbackLabel || 'default';
 
       /* let credentials be supplied in the recognizer object at runtime */
       this.sttCredentials = setSpeechCredentialsAtRuntime(recognizer);
@@ -133,11 +138,60 @@ class TaskGather extends Task {
     return s;
   }
 
+  async _initSpeechCredentials(cs, vendor, label) {
+    const {getNuanceAccessToken, getIbmAccessToken} = this.cs.srf.locals.dbHelpers;
+    let credentials = cs.getSpeechCredentials(vendor, 'stt', label);
+
+    if (!credentials) {
+      const {writeAlerts, AlertType} = cs.srf.locals;
+      this.logger.info(`TaskGather:exec - ERROR stt using ${vendor} requested but creds not supplied`);
+      writeAlerts({
+        account_sid: cs.accountSid,
+        alert_type: AlertType.STT_NOT_PROVISIONED,
+        vendor
+      }).catch((err) => this.logger.info({err}, 'Error generating alert for no stt'));
+      // Notify application that STT vender is wrong.
+      this.notifyError({
+        msg: 'ASR error',
+        details: `No speech-to-text service credentials for ${vendor} have been configured`
+      });
+      this.notifyTaskDone();
+      throw new Error(`No speech-to-text service credentials for ${vendor} have been configured`);
+    }
+
+    if (vendor === 'nuance' && credentials.client_id) {
+      /* get nuance access token */
+      const {client_id, secret} = credentials;
+      const {access_token, servedFromCache} = await getNuanceAccessToken(client_id, secret, 'asr tts');
+      this.logger.debug({client_id}, `Gather:exec - got nuance access token ${servedFromCache ? 'from cache' : ''}`);
+      credentials = {...credentials, access_token};
+    }
+    else if (vendor == 'ibm' && credentials.stt_api_key) {
+      /* get ibm access token */
+      const {stt_api_key, stt_region} = credentials;
+      const {access_token, servedFromCache} = await getIbmAccessToken(stt_api_key);
+      this.logger.debug({stt_api_key}, `Gather:exec - got ibm access token ${servedFromCache ? 'from cache' : ''}`);
+      credentials = {...credentials, access_token, stt_region};
+    }
+    return credentials;
+  }
+
+  async _startTranscribeForSpeech(cs, ep, vendor, language, credentials) {
+    const {updateSpeechCredentialLastUsed} = require('../utils/db-utils')(this.logger, cs.srf);
+    await this._initSpeech(cs, ep, vendor, credentials);
+    if (this.killed) {
+      this.logger.info(`Gather:exec - task was quickly killed so do not transcribe for vendor: ${vendor}`);
+      return;
+    }
+    this.execVendor = vendor;
+    this.execLanguage = language;
+    this._startTranscribing(ep);
+    return updateSpeechCredentialLastUsed(credentials.speech_credential_sid);
+  }
+
   async exec(cs, {ep}) {
     this.logger.debug({options: this.data}, 'Gather:exec');
     await super.exec(cs);
-    const {updateSpeechCredentialLastUsed} = require('../utils/db-utils')(this.logger, cs.srf);
-    const {getNuanceAccessToken, getIbmAccessToken} = cs.srf.locals.dbHelpers;
 
     if (cs.hasGlobalSttHints && !this.maskGlobalSttHints) {
       const {hints, hintsBoost} = cs.globalSttHints;
@@ -184,58 +238,55 @@ class TaskGather extends Task {
       this.language = cs.speechRecognizerLanguage;
       if (this.data.recognizer) this.data.recognizer.language = this.language;
     }
+    if ('default' === this.label || !this.label) {
+      this.label = cs.speechRecognizerLabel;
+      if (this.data.recognizer) this.data.recognizer.label = this.label;
+    }
+    // Fallback options
+    if ('default' === this.fallbackVendor || !this.fallbackVendor) {
+      this.fallbackVendor = cs.fallbackSpeechRecognizerVendor;
+      if (this.data.recognizer) this.data.recognizer.fallbackVendor = this.fallbackVendor;
+    }
+    if ('default' === this.fallbackLanguage || !this.fallbackLanguage) {
+      this.fallbackLanguage = cs.fallbackSpeechRecognizerLanguage;
+      if (this.data.recognizer) this.data.recognizer.fallbackLanguage = this.fallbackLanguage;
+    }
+    if ('default' === this.fallbackLabel || !this.fallbackLabel) {
+      this.fallbackLabel = cs.fallbackSpeechRecognizerLabel;
+      if (this.data.recognizer) this.data.recognizer.fallbackLabel = this.fallbackLabel;
+    }
+
     if (!this.data.recognizer.vendor) {
       this.data.recognizer.vendor = this.vendor;
     }
-    if (this.needsStt && !this.sttCredentials) this.sttCredentials =
-      cs.getSpeechCredentials(this.vendor, 'stt', this.data.recognizer?.label || cs.speechRecognizerLabel);
+
     if (this.needsStt && !this.sttCredentials) {
-      const {writeAlerts, AlertType} = cs.srf.locals;
-      this.logger.info(`TaskGather:exec - ERROR stt using ${this.vendor} requested but creds not supplied`);
-      writeAlerts({
-        account_sid: cs.accountSid,
-        alert_type: AlertType.STT_NOT_PROVISIONED,
-        vendor: this.vendor
-      }).catch((err) => this.logger.info({err}, 'Error generating alert for no stt'));
-      // Notify application that STT vender is wrong.
-      this.notifyError({
-        msg: 'ASR error',
-        details: `No speech-to-text service credentials for ${this.vendor} have been configured`
-      });
-      this.notifyTaskDone();
-      throw new Error(`No speech-to-text service credentials for ${this.vendor} have been configured`);
+      this.sttCredentials = await this._initSpeechCredentials(cs, this.vendor, this.label);
     }
 
-    if (this.vendor === 'nuance' && this.sttCredentials.client_id) {
-      /* get nuance access token */
-      const {client_id, secret} = this.sttCredentials;
-      const {access_token, servedFromCache} = await getNuanceAccessToken(client_id, secret, 'asr tts');
-      this.logger.debug({client_id}, `Gather:exec - got nuance access token ${servedFromCache ? 'from cache' : ''}`);
-      this.sttCredentials = {...this.sttCredentials, access_token};
+    // Fetch credential for fallback recognizer
+    if (this.needsStt && !this.fallbackSttCredentials && this.fallbackVendor) {
+      this.fallbackSttCredentials = await this._initSpeechCredentials(
+        cs, this.fallbackSttCredentials, this.fallbackLabel);
     }
-    else if (this.vendor == 'ibm' && this.sttCredentials.stt_api_key) {
-      /* get ibm access token */
-      const {stt_api_key, stt_region} = this.sttCredentials;
-      const {access_token, servedFromCache} = await getIbmAccessToken(stt_api_key);
-      this.logger.debug({stt_api_key}, `Gather:exec - got ibm access token ${servedFromCache ? 'from cache' : ''}`);
-      this.sttCredentials = {...this.sttCredentials, access_token, stt_region};
-    }
-    const startListening = (cs, ep) => {
+
+    const startListening = async(cs, ep) => {
       this._startTimer();
       if (this.isContinuousAsr && 0 === this.timeout) this._startAsrTimer();
       if (this.input.includes('speech') && !this.listenDuringPrompt) {
-        this._initSpeech(cs, ep)
-          .then(() => {
-            if (this.killed) {
-              this.logger.info('Gather:exec - task was quickly killed so do not transcribe');
-              return;
+        try {
+          return await this._startTranscribeForSpeech(cs, ep, this.vendor, this.language, this.sttCredentials);
+        } catch (error) {
+          this.logger.error({error}, 'error in initSpeech');
+          if (this.fallbackSttCredentials) {
+            try {
+              return await this._startTranscribeForSpeech(cs, ep, this.fallbackVendor,
+                this.fallbackLanguage, this.fallbackSttCredentials);
+            } catch (err) {
+              this.logger.error({err}, `error in initSpeech for fallback STT provider ${this.fallbackVendor}`);
             }
-            this._startTranscribing(ep);
-            return updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid);
-          })
-          .catch((err) => {
-            this.logger.error({err}, 'error in initSpeech');
-          });
+          }
+        }
       }
     };
 
@@ -289,10 +340,19 @@ class TaskGather extends Task {
       }
 
       if (this.input.includes('speech') && this.listenDuringPrompt) {
-        await this._initSpeech(cs, ep);
-        this._startTranscribing(ep);
-        updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid)
-          .catch(() => {/*already logged error */});
+        try {
+          await this._startTranscribeForSpeech(cs, ep, this.vendor, this.language, this.sttCredentials);
+        } catch (error) {
+          this.logger.error({error}, 'error in initSpeech');
+          if (this.fallbackSttCredentials) {
+            try {
+              await this._startTranscribeForSpeech(cs, ep, this.fallbackVendor,
+                this.fallbackLanguage, this.fallbackSttCredentials);
+            } catch (err) {
+              this.logger.error({err}, `error in initSpeech for fallback STT provider ${this.fallbackVendor}`);
+            }
+          }
+        }
       }
 
       if (this.input.includes('digits') || this.dtmfBargein || this.asrDtmfTerminationDigit) {
@@ -363,9 +423,9 @@ class TaskGather extends Task {
     }
   }
 
-  async _initSpeech(cs, ep) {
-    const opts = this.setChannelVarsForStt(this, this.sttCredentials, this.data.recognizer);
-    switch (this.vendor) {
+  async _initSpeech(cs, ep, vendor, credentials) {
+    const opts = this.setChannelVarsForStt(this, credentials, this.data.recognizer);
+    switch (vendor) {
       case 'google':
         this.bugname = 'google_transcribe';
         ep.addCustomEventListener(GoogleTranscriptionEvents.Transcription, this._onTranscription.bind(this, cs, ep));
@@ -451,9 +511,9 @@ class TaskGather extends Task {
           break;
         }
         else {
-          this.notifyError({ msg: 'ASR error', details:`Invalid vendor ${this.vendor}`});
+          this.notifyError({ msg: 'ASR error', details:`Invalid vendor ${credentials.vendor}`});
           this.notifyTaskDone();
-          throw new Error(`Invalid vendor ${this.vendor}`);
+          throw new Error(`Invalid vendor ${credentials.vendor}`);
         }
     }
 
@@ -465,14 +525,14 @@ class TaskGather extends Task {
 
   _startTranscribing(ep) {
     this.logger.debug({
-      vendor: this.vendor,
-      locale: this.language,
+      vendor: this.execVendor,
+      locale: this.execLanguage,
       interim: this.interim,
       bugname: this.bugname
     }, 'Gather:_startTranscribing');
     ep.startTranscription({
-      vendor: this.vendor,
-      locale: this.language,
+      vendor: this.execVendor,
+      locale: this.execLanguage,
       interim: this.interim,
       bugname: this.bugname,
     }).catch((err) => {
@@ -481,7 +541,7 @@ class TaskGather extends Task {
       writeAlerts({
         account_sid: this.cs.accountSid,
         alert_type: AlertType.STT_FAILURE,
-        vendor: this.vendor,
+        vendor: this.execVendor,
         detail: err.message
       });
     }).catch((err) => this.logger.info({err}, 'Error generating alert for tts failure'));

lib/tasks/lex.js

@@ -26,6 +26,12 @@ class Lex extends Task {
       this.language = this.data.tts.language || 'default';
       this.voice = this.data.tts.voice || 'default';
       this.speechCredentialLabel = this.data.tts.label || null;
+
+      // fallback tts
+      this.fallbackVendor = this.data.tts.fallbackVendor || 'default';
+      this.fallbackLanguage = this.data.tts.fallbackLanguage || 'default';
+      this.fallbackVoice = this.data.tts.fallbackLanguage || 'default';
+      this.fallbackLabel = this.data.tts.fallbackLabel || 'default';
     }
 
     this.botName = `${this.bot}:${this.alias}:${this.region}`;
@@ -103,9 +109,15 @@ class Lex extends Task {
         this.vendor = cs.speechSynthesisVendor;
         this.language = cs.speechSynthesisLanguage;
         this.voice = cs.speechSynthesisVoice;
+        this.speechCredentialLabel = cs.speechSynthesisLabel;
       }
-      this.ttsCredentials = cs.getSpeechCredentials(this.vendor, 'tts',
-        this.speechCredentialLabel || cs.speechSynthesisVendor);
+      if (this.fallbackVendor === 'default') {
+        this.fallbackVendor = cs.fallbackSpeechSynthesisVendor;
+        this.fallbackLanguage = cs.fallbackSpeechSynthesisLanguage;
+        this.fallbackVoice = cs.fallbackSpeechSynthesisVoice;
+        this.fallbackLabel = cs.fallbackSpeechSynthesisLabel;
+      }
+      this.ttsCredentials = cs.getSpeechCredentials(this.vendor, 'tts', this.speechCredentialLabel);
 
       this.ep.addCustomEventListener('lex::intent', this._onIntent.bind(this, ep, cs));
       this.ep.addCustomEventListener('lex::transcription', this._onTranscription.bind(this, ep, cs));
@@ -170,6 +182,41 @@ class Lex extends Task {
     }
   }
 
+  async fallbackSynthAudio(cs, msg, stats, synthAudio) {
+    try {
+      const {filePath} = await synthAudio(stats, {
+        account_sid: cs.accountSid,
+        text: msg,
+        vendor: this.vendor,
+        language: this.language,
+        voice: this.voice,
+        salt: cs.callSid,
+        credentials: this.ttsCredentials
+      });
+
+      return filePath;
+    } catch (error) {
+      this.logger.info({error}, 'failed to synth audio from primary vendor');
+      if (this.fallbackVendor) {
+        try {
+          const credential = cs.getSpeechCredentials(this.fallbackVendor, 'tts', this.fallbackLabel);
+          const {filePath} = await synthAudio(stats, {
+            account_sid: cs.accountSid,
+            text: msg,
+            vendor: this.fallbackVendor,
+            language: this.fallbackLanguage,
+            voice: this.fallbackVoice,
+            salt: cs.callSid,
+            credentials: credential
+          });
+          return filePath;
+        } catch (err) {
+          this.logger.info({err}, 'failed to synth audio from fallback vendor');
+        }
+      }
+    }
+  }
+
   /**
    * @param {*} evt - event data
    */
@@ -189,16 +236,7 @@ class Lex extends Task {
 
         try {
           this.logger.debug(`tts with ${this.vendor} ${this.voice}`);
-          // eslint-disable-next-line no-unused-vars
-          const {filePath, servedFromCache} = await synthAudio(stats, {
-            account_sid: cs.accountSid,
-            text: msg,
-            vendor: this.vendor,
-            language: this.language,
-            voice: this.voice,
-            salt: cs.callSid,
-            credentials: this.ttsCredentials
-          });
+          const filePath = await this.fallbackSynthAudio(cs, msg, stats, synthAudio);
           if (filePath) cs.trackTmpFile(filePath);
 
           if (this.events.includes('start-play')) {

lib/tasks/say.js

@@ -59,15 +59,30 @@ class TaskSay extends Task {
     const vendor = this.synthesizer.vendor && this.synthesizer.vendor !== 'default' ?
       this.synthesizer.vendor :
       cs.speechSynthesisVendor;
+    const fallbackVendor = this.synthesizer.fallbackVendor && this.synthesizer.fallbackVendor !== 'default' ?
+      this.synthesizer.fallbackVendor :
+      cs.fallbackSpeechSynthesisVendor;
     const language = this.synthesizer.language && this.synthesizer.language !== 'default' ?
       this.synthesizer.language :
       cs.speechSynthesisLanguage ;
+    const fallbackLanguage = this.synthesizer.fallbackLanguage && this.synthesizer.fallbackLanguage !== 'default' ?
+      this.synthesizer.fallbackLanguage :
+      cs.fallbackSpeechSynthesisLanguage ;
     let voice =  this.synthesizer.voice && this.synthesizer.voice !== 'default' ?
       this.synthesizer.voice :
       cs.speechSynthesisVoice;
+    const fallbackVoice = this.synthesizer.fallbackVoice && this.synthesizer.fallbackVoice !== 'default' ?
+      this.synthesizer.fallbackVoice :
+      cs.fallbackSpeechSynthesisVoice;
+    const label = this.synthesizer.label && this.synthesizer.label !== 'default' ?
+      this.synthesizer.label :
+      cs.speechSynthesisLabel;
+    const fallbackLabel = this.synthesizer.fallbackLabel && this.synthesizer.fallbackLabel !== 'default' ?
+      this.synthesizer.fallbackLabel :
+      cs.fallbackSpeechSynthesisLabel;
     const engine = this.synthesizer.engine || 'standard';
     const salt = cs.callSid;
-    let credentials = cs.getSpeechCredentials(vendor, 'tts', this.data.synthesizer?.label || cs.speechSynthesisLabel);
+    let credentials = cs.getSpeechCredentials(vendor, 'tts', label);
 
     /* parse Nuance voices into name and model */
     let model;
@@ -118,6 +133,8 @@ class TaskSay extends Task {
           'tts.language': language,
           'tts.voice': voice
         });
+        let filePathUrl, isFromCache, roundTripTime;
+        let executedVendor, executedLanguage;
         try {
           const {filePath, servedFromCache, rtt} = await synthAudio(stats, {
             account_sid: cs.accountSid,
@@ -131,37 +148,101 @@ class TaskSay extends Task {
             credentials,
             disableTtsCache : this.disableTtsCache
           });
-          this.logger.debug(`file ${filePath}, served from cache ${servedFromCache}`);
-          if (filePath) cs.trackTmpFile(filePath);
+
+          span.setAttributes({'tts.cached': servedFromCache});
+          span.end();
+
           if (!servedFromCache && !lastUpdated) {
             lastUpdated = true;
             updateSpeechCredentialLastUsed(credentials.speech_credential_sid)
               .catch(() => {/*already logged error */});
           }
-          span.setAttributes({'tts.cached': servedFromCache});
-          span.end();
-          if (!servedFromCache && rtt) {
-            this.notifyStatus({
-              event: 'synthesized-audio',
-              vendor,
-              language,
-              characters: text.length,
-              elapsedTime: rtt
+
+          filePathUrl = filePath;
+          isFromCache = servedFromCache;
+          roundTripTime = rtt;
+          executedVendor = vendor;
+          executedLanguage = language;
+
+        } catch (error) {
+          let isFallbackSuccess = false;
+          if (fallbackVendor) {
+            const fallbackcredentials = cs.getSpeechCredentials(fallbackVendor, 'tts', fallbackLabel);
+            const {span: fallbackSpan} = this.startChildSpan('fallback-tts-generation', {
+              'tts.vendor': fallbackVendor,
+              'tts.language': fallbackLanguage,
+              'tts.voice': fallbackVoice
             });
+
+            try {
+              const {filePath, servedFromCache, rtt} = await synthAudio(stats, {
+                account_sid: cs.accountSid,
+                text,
+                vendor: fallbackVendor,
+                language: fallbackLanguage,
+                voice: fallbackVoice,
+                engine,
+                model,
+                salt,
+                credentials: fallbackcredentials,
+                disableTtsCache : this.disableTtsCache
+              });
+              isFallbackSuccess = true;
+
+              fallbackSpan.setAttributes({'tts.cached': servedFromCache});
+              fallbackSpan.end();
+
+              if (!servedFromCache && !lastUpdated) {
+                lastUpdated = true;
+                updateSpeechCredentialLastUsed(credentials.speech_credential_sid)
+                  .catch(() => {/*already logged error */});
+              }
+
+              filePathUrl = filePath;
+              isFromCache = servedFromCache;
+              roundTripTime = rtt;
+              executedVendor = fallbackVendor;
+              executedLanguage = fallbackLanguage;
+
+            } catch (err) {
+              this.logger.info({err}, 'fallback Speech failed to synthesize audio');
+              fallbackSpan.end();
+              writeAlerts({
+                account_sid: cs.accountSid,
+                alert_type: AlertType.TTS_FAILURE,
+                vendor: fallbackVendor,
+                detail: err.message
+              }).catch((err) => this.logger.info({err}, 'Error generating alert for fallback tts failure'));
+            }
+          }
+          if (!isFallbackSuccess) {
+            this.logger.info({error}, 'Error synthesizing tts');
+            span.end();
+            writeAlerts({
+              account_sid: cs.accountSid,
+              alert_type: AlertType.TTS_FAILURE,
+              vendor,
+              detail: error.message
+            }).catch((err) => this.logger.info({err}, 'Error generating alert for tts failure'));
+            this.notifyError({msg: 'TTS error', details: error.message || error});
+            return;
           }
-          return filePath;
-        } catch (err) {
-          this.logger.info({err}, 'Error synthesizing tts');
-          span.end();
-          writeAlerts({
-            account_sid: cs.accountSid,
-            alert_type: AlertType.TTS_FAILURE,
-            vendor,
-            detail: err.message
-          }).catch((err) => this.logger.info({err}, 'Error generating alert for tts failure'));
-          this.notifyError({msg: 'TTS error', details: err.message || err});
-          return;
         }
+
+        this.logger.debug(`file ${filePathUrl}, served from cache ${isFromCache}`);
+        if (filePathUrl) cs.trackTmpFile(filePathUrl);
+
+        if (!isFromCache && roundTripTime) {
+          this.notifyStatus({
+            event: 'synthesized-audio',
+            vendor: executedVendor,
+            language: executedLanguage,
+            characters: text.length,
+            elapsedTime: roundTripTime
+          });
+        }
+
+        return filePathUrl;
       };
 
       const arr = this.text.map((t) => generateAudio(t));

lib/tasks/transcribe.js

@@ -42,6 +42,11 @@ class TaskTranscribe extends Task {
       const recognizer = this.data.recognizer;
       this.vendor = recognizer.vendor;
       this.language = recognizer.language;
+      this.label = recognizer.label;
+
+      this.fallbackVendor = recognizer.fallbackVendor || 'default';
+      this.fallbackLanguage = recognizer.fallbackLanguage || 'default';
+      this.fallbackLabel = recognizer.fallbackLabel || 'default';
       /* let credentials be supplied in the recognizer object at runtime */
       this.sttCredentials = setSpeechCredentialsAtRuntime(recognizer);
 
@@ -67,10 +72,43 @@ class TaskTranscribe extends Task {
 
   get name() { return TaskName.Transcribe; }
 
+  async _initSpeechCredential(cs, vendor, label) {
+    const {getNuanceAccessToken, getIbmAccessToken} = cs.srf.locals.dbHelpers;
+    let credentials = cs.getSpeechCredentials(vendor, 'stt', label);
+
+    if (!credentials) {
+      const {writeAlerts, AlertType} = cs.srf.locals;
+      this.logger.info(`TaskTranscribe:exec - ERROR stt using ${vendor} requested but creds not supplied`);
+      writeAlerts({
+        account_sid: cs.accountSid,
+        alert_type: AlertType.STT_NOT_PROVISIONED,
+        vendor: vendor
+      }).catch((err) => this.logger.info({err}, 'Error generating alert for no stt'));
+      throw new Error('no provisioned speech credentials for TTS');
+    }
+
+    if (vendor === 'nuance' && credentials.client_id) {
+      /* get nuance access token */
+      const {client_id, secret} = credentials;
+      const {access_token, servedFromCache} = await getNuanceAccessToken(client_id, secret, 'asr tts');
+      this.logger.debug({client_id},
+        `Transcribe:exec - got nuance access token ${servedFromCache ? 'from cache' : ''}`);
+      credentials = {...credentials, access_token};
+    }
+    else if (vendor == 'ibm' && credentials.stt_api_key) {
+      /* get ibm access token */
+      const {stt_api_key, stt_region} = credentials;
+      const {access_token, servedFromCache} = await getIbmAccessToken(stt_api_key);
+      this.logger.debug({stt_api_key}, `Gather:exec - got ibm access token ${servedFromCache ? 'from cache' : ''}`);
+      credentials = {...credentials, access_token, stt_region};
+    }
+
+    return credentials;
+  }
+
   async exec(cs, {ep, ep2}) {
     super.exec(cs);
     const {updateSpeechCredentialLastUsed} = require('../utils/db-utils')(this.logger, cs.srf);
-    const {getNuanceAccessToken, getIbmAccessToken} = cs.srf.locals.dbHelpers;
 
     if (cs.hasGlobalSttHints) {
       const {hints, hintsBoost} = cs.globalSttHints;
@@ -98,51 +136,60 @@ class TaskTranscribe extends Task {
       this.language = cs.speechRecognizerLanguage;
       if (this.data.recognizer) this.data.recognizer.language = this.language;
     }
+    if ('default' === this.label || !this.label) {
+      this.label = cs.speechRecognizerLabel;
+      if (this.data.recognizer) this.data.recognizer.label = this.label;
+    }
+    // fallback options
+    if ('default' === this.fallbackVendor || !this.fallbackVendor) {
+      this.fallbackVendor = cs.fallbackSpeechRecognizerVendor;
+      if (this.data.recognizer) this.data.recognizer.fallbackVendor = this.fallbackVendor;
+    }
+    if ('default' === this.fallbackLanguage || !this.fallbackLanguage) {
+      this.fallbackLanguage = cs.fallbackSpeechRecognizerLanguage;
+      if (this.data.recognizer) this.data.recognizer.fallbackLanguage = this.fallbackLanguage;
+    }
+    if ('default' === this.fallbackLabel || !this.fallbackLabel) {
+      this.label = cs.fallbackSpeechRecognizerLabel;
+      if (this.data.recognizer) this.data.recognizer.fallbackLabel = this.fallbackLabel;
+    }
     if (!this.data.recognizer.vendor) {
       this.data.recognizer.vendor = this.vendor;
     }
-    if (!this.sttCredentials) this.sttCredentials =
-      cs.getSpeechCredentials(this.vendor, 'stt', this.data.recognizer?.label || cs.speechRecognizerLabel);
+    if (!this.sttCredentials) {
+      this.sttCredentials = await this._initSpeechCredential(cs, this.vendor, this.label);
+    }
 
+    if (!this.fallbackSttCredentials) {
+      this.fallbackSttCredentials = await this._initSpeechCredential(cs, this.fallbackVendor, this.fallbackLabel);
+    }
     try {
-      if (!this.sttCredentials) {
-        const {writeAlerts, AlertType} = cs.srf.locals;
-        this.logger.info(`TaskTranscribe:exec - ERROR stt using ${this.vendor} requested but creds not supplied`);
-        writeAlerts({
-          account_sid: cs.accountSid,
-          alert_type: AlertType.STT_NOT_PROVISIONED,
-          vendor: this.vendor
-        }).catch((err) => this.logger.info({err}, 'Error generating alert for no stt'));
-        throw new Error('no provisioned speech credentials for TTS');
-      }
-
-      if (this.vendor === 'nuance' && this.sttCredentials.client_id) {
-        /* get nuance access token */
-        const {client_id, secret} = this.sttCredentials;
-        const {access_token, servedFromCache} = await getNuanceAccessToken(client_id, secret, 'asr tts');
-        this.logger.debug({client_id},
-          `Transcribe:exec - got nuance access token ${servedFromCache ? 'from cache' : ''}`);
-        this.sttCredentials = {...this.sttCredentials, access_token};
-      }
-      else if (this.vendor == 'ibm' && this.sttCredentials.stt_api_key) {
-        /* get ibm access token */
-        const {stt_api_key, stt_region} = this.sttCredentials;
-        const {access_token, servedFromCache} = await getIbmAccessToken(stt_api_key);
-        this.logger.debug({stt_api_key}, `Gather:exec - got ibm access token ${servedFromCache ? 'from cache' : ''}`);
-        this.sttCredentials = {...this.sttCredentials, access_token, stt_region};
-      }
-      await this._startTranscribing(cs, ep, 1);
+      await this._startTranscribing(cs, ep, 1, this.sttCredentials);
       if (this.separateRecognitionPerChannel && ep2) {
-        await this._startTranscribing(cs, ep2, 2);
+        await this._startTranscribing(cs, ep2, 2, this.sttCredentials);
       }
-
-      updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid)
-        .catch(() => {/*already logged error */});
-
+      updateSpeechCredentialLastUsed(this.sttCredentials.speech_credential_sid);
       await this.awaitTaskDone();
     } catch (err) {
       this.logger.info(err, 'TaskTranscribe:exec - error');
-      this.parentTask && this.parentTask.emit('error', err);
+      let isFallbackSuccess = false;
+      if (this.fallbackSttCredentials) {
+        this.logger.info(err, 'TaskTranscribe:exec - fallback to 2nd speech provider');
+        try {
+          await this._startTranscribing(cs, ep, 1, this.fallbackSttCredentials);
+          if (this.separateRecognitionPerChannel && ep2) {
+            await this._startTranscribing(cs, ep2, 2, this.fallbackSttCredentials);
+          }
+          updateSpeechCredentialLastUsed(this.fallbackSttCredentials.speech_credential_sid);
+          await this.awaitTaskDone();
+          isFallbackSuccess = true;
+        } catch (error) {
+          this.logger.info(err, 'TaskTranscribe:exec - fallback error');
+        }
+      }
+      if (!isFallbackSuccess) {
+        this.parentTask && this.parentTask.emit('error', err);
+      }
     }
     this.removeSpeechListeners(ep);
   }
@@ -167,8 +214,8 @@ class TaskTranscribe extends Task {
     await this.awaitTaskDone();
   }
 
-  async _startTranscribing(cs, ep, channel) {
-    const opts = this.setChannelVarsForStt(this, this.sttCredentials, this.data.recognizer);
+  async _startTranscribing(cs, ep, channel, credentials) {
+    const opts = this.setChannelVarsForStt(this, credentials, this.data.recognizer);
     switch (this.vendor) {
       case 'google':
         this.bugname = 'google_transcribe';

package-lock.json

@@ -17,7 +17,7 @@
         "@jambonz/speech-utils": "^0.0.19",
         "@jambonz/stats-collector": "^0.1.9",
         "@jambonz/time-series": "^0.2.8",
-        "@jambonz/verb-specifications": "^0.0.27",
+        "@jambonz/verb-specifications": "^0.0.29",
         "@opentelemetry/api": "^1.4.0",
         "@opentelemetry/exporter-jaeger": "^1.9.0",
         "@opentelemetry/exporter-trace-otlp-http": "^0.35.0",
@@ -3019,9 +3019,9 @@
       }
     },
     "node_modules/@jambonz/verb-specifications": {
-      "version": "0.0.27",
-      "resolved": "https://registry.npmjs.org/@jambonz/verb-specifications/-/verb-specifications-0.0.27.tgz",
-      "integrity": "sha512-DIcxhCNrgr2RTE3YrGNP15RqKyV+P8f97SPBlKd2zTM5aN2oV5xv+pRDx5gLzmrUZ5TIEaBXQN3vTmM2Zx5Q6g==",
+      "version": "0.0.29",
+      "resolved": "https://registry.npmjs.org/@jambonz/verb-specifications/-/verb-specifications-0.0.29.tgz",
+      "integrity": "sha512-jeYI+GN7Y5nXhdFG3SXvXaBlhCjIC+l5AcBywDDGxxyuuKRTukPS0MSvCtWPZP6H3wYYGqfJ4DR/vgtBF3pvyQ==",
       "dependencies": {
         "debug": "^4.3.4",
         "pino": "^8.8.0"
@@ -12985,9 +12985,9 @@
       }
     },
     "@jambonz/verb-specifications": {
-      "version": "0.0.27",
-      "resolved": "https://registry.npmjs.org/@jambonz/verb-specifications/-/verb-specifications-0.0.27.tgz",
-      "integrity": "sha512-DIcxhCNrgr2RTE3YrGNP15RqKyV+P8f97SPBlKd2zTM5aN2oV5xv+pRDx5gLzmrUZ5TIEaBXQN3vTmM2Zx5Q6g==",
+      "version": "0.0.29",
+      "resolved": "https://registry.npmjs.org/@jambonz/verb-specifications/-/verb-specifications-0.0.29.tgz",
+      "integrity": "sha512-jeYI+GN7Y5nXhdFG3SXvXaBlhCjIC+l5AcBywDDGxxyuuKRTukPS0MSvCtWPZP6H3wYYGqfJ4DR/vgtBF3pvyQ==",
       "requires": {
         "debug": "^4.3.4",
         "pino": "^8.8.0"

package.json

@@ -31,7 +31,7 @@
     "@jambonz/speech-utils": "^0.0.19",
     "@jambonz/stats-collector": "^0.1.9",
     "@jambonz/time-series": "^0.2.8",
-    "@jambonz/verb-specifications": "^0.0.27",
+    "@jambonz/verb-specifications": "^0.0.29",
     "@opentelemetry/api": "^1.4.0",
     "@opentelemetry/exporter-jaeger": "^1.9.0",
     "@opentelemetry/exporter-trace-otlp-http": "^0.35.0",

test/index.js

@@ -7,7 +7,7 @@ require('./dial-tests');
 require('./webhooks-tests');
 require('./say-tests');
 require('./gather-tests');
-// require('./transcribe-tests');
+require('./transcribe-tests');
 require('./sip-request-tests');
 require('./create-call-test');
 require('./play-tests');