support mod_vad_detect (#762)

* support mod_vad_detect

* wip

* update verb spec and drachtio fsmrf

* Update example-voicemail-greetings.json (#761)

Update voicemail english greetings

* wip

* stopvad if playdone

---------

Co-authored-by: Vinod Dharashive <vdharashive@gmail.com>

lib/tasks/gather.js

@@ -10,7 +10,8 @@ const {
   IbmTranscriptionEvents,
   NvidiaTranscriptionEvents,
   JambonzTranscriptionEvents,
-  AssemblyAiTranscriptionEvents
+  AssemblyAiTranscriptionEvents,
+  VadDetection
 } = require('../utils/constants.json');
 const {
   JAMBONES_GATHER_EARLY_HINTS_MATCH,
@@ -27,7 +28,7 @@ class TaskGather extends SttTask {
     [
       'finishOnKey', 'input', 'numDigits', 'minDigits', 'maxDigits',
       'interDigitTimeout', 'partialResultHook', 'bargein', 'dtmfBargein',
-      'speechTimeout', 'timeout', 'say', 'play', 'actionHookDelayAction', 'fillerNoise'
+      'speechTimeout', 'timeout', 'say', 'play', 'actionHookDelayAction', 'fillerNoise', 'vad'
     ].forEach((k) => this[k] = this.data[k]);
 
     // gather default input is digits
@@ -41,7 +42,8 @@ class TaskGather extends SttTask {
     this.timeout = this.timeout === 0 ? 0 : (this.timeout || 15) * 1000;
     this.interim = !!this.partialResultHook || this.bargein || (this.timeout > 0);
     this.listenDuringPrompt = this.data.listenDuringPrompt === false ? false : true;
-    this.minBargeinWordCount = this.data.minBargeinWordCount || 1;
+    this.minBargeinWordCount = this.data.minBargeinWordCount !== undefined ? this.data.minBargeinWordCount : 1;
+    this._vadEnabled = this.minBargeinWordCount === 0;
     if (this.data.recognizer) {
       /* continuous ASR (i.e. compile transcripts until a special timeout or dtmf key) */
       this.asrTimeout = typeof this.data.recognizer.asrTimeout === 'number' ?
@@ -128,6 +130,11 @@ class TaskGather extends SttTask {
       ...(this.fillerNoise || {})
     };
 
+    this.vad = {
+      ...(cs.vad || {}),
+      ...(this.vad || {})
+    };
+
     if (cs.hasGlobalSttHints && !this.maskGlobalSttHints) {
       const {hints, hintsBoost} = cs.globalSttHints;
       const setOfHints = new Set((this.data.recognizer.hints || [])
@@ -178,6 +185,8 @@ class TaskGather extends SttTask {
       retries: this._hookDelayRetries
     };
 
+    this._startVad();
+
     const startListening = async(cs, ep) => {
       this._startTimer();
       if (this.isContinuousAsr && 0 === this.timeout) this._startAsrTimer();
@@ -201,6 +210,7 @@ class TaskGather extends SttTask {
         const {span, ctx} = this.startChildSpan(`nested:${this.sayTask.summary}`);
         const process = () => {
           this.logger.debug('Gather: nested say task completed');
+          this._stopVad();
           if (!this.killed) {
             startListening(cs, ep);
             if (this.input.includes('speech') && this.vendor === 'nuance' && this.listenDuringPrompt) {
@@ -227,6 +237,7 @@ class TaskGather extends SttTask {
         const {span, ctx} = this.startChildSpan(`nested:${this.playTask.summary}`);
         const process = () => {
           this.logger.debug('Gather: nested play task completed');
+          this._stopVad();
           if (!this.killed) {
             startListening(cs, ep);
             if (this.input.includes('speech') && this.vendor === 'nuance' && this.listenDuringPrompt) {
@@ -291,6 +302,7 @@ class TaskGather extends SttTask {
     this._clearAsrTimer();
     this.playTask?.span.end();
     this.sayTask?.span.end();
+    this._stopVad();
     this._resolve('killed');
   }
 
@@ -368,15 +380,12 @@ class TaskGather extends SttTask {
           ep, GoogleTranscriptionEvents.Transcription, this._onTranscription.bind(this, cs, ep));
         this.addCustomEventListener(
           ep, GoogleTranscriptionEvents.EndOfUtterance, this._onEndOfUtterance.bind(this, cs, ep));
-        this.addCustomEventListener(
-          ep, GoogleTranscriptionEvents.VadDetected, this._onVadDetected.bind(this, cs, ep));
         break;
 
       case 'aws':
       case 'polly':
         this.bugname = `${this.bugname_prefix}aws_transcribe`;
         this.addCustomEventListener(ep, AwsTranscriptionEvents.Transcription, this._onTranscription.bind(this, cs, ep));
-        this.addCustomEventListener(ep, AwsTranscriptionEvents.VadDetected, this._onVadDetected.bind(this, cs, ep));
         break;
       case 'microsoft':
         this.bugname = `${this.bugname_prefix}azure_transcribe`;
@@ -384,7 +393,6 @@ class TaskGather extends SttTask {
           ep, AzureTranscriptionEvents.Transcription, this._onTranscription.bind(this, cs, ep));
         //this.addCustomEventListener(ep, AzureTranscriptionEvents.NoSpeechDetected,
         //this._onNoSpeechDetected.bind(this, cs, ep));
-        this.addCustomEventListener(ep, AzureTranscriptionEvents.VadDetected, this._onVadDetected.bind(this, cs, ep));
         break;
       case 'nuance':
         this.bugname = `${this.bugname_prefix}nuance_transcribe`;
@@ -394,8 +402,6 @@ class TaskGather extends SttTask {
           this._onStartOfSpeech.bind(this, cs, ep));
         this.addCustomEventListener(ep, NuanceTranscriptionEvents.TranscriptionComplete,
           this._onTranscriptionComplete.bind(this, cs, ep));
-        this.addCustomEventListener(ep, NuanceTranscriptionEvents.VadDetected,
-          this._onVadDetected.bind(this, cs, ep));
 
         /* stall timers until prompt finishes playing */
         if ((this.sayTask || this.playTask) && this.listenDuringPrompt) {
@@ -465,8 +471,6 @@ class TaskGather extends SttTask {
           this._onStartOfSpeech.bind(this, cs, ep));
         this.addCustomEventListener(ep, NvidiaTranscriptionEvents.TranscriptionComplete,
           this._onTranscriptionComplete.bind(this, cs, ep));
-        this.addCustomEventListener(ep, NvidiaTranscriptionEvents.VadDetected,
-          this._onVadDetected.bind(this, cs, ep));
 
         /* I think nvidia has this (??) - stall timers until prompt finishes playing */
         if ((this.sayTask || this.playTask) && this.listenDuringPrompt) {
@@ -704,6 +708,25 @@ class TaskGather extends SttTask {
     this._finalAsrTimer = null;
   }
 
+
+  _startVad() {
+    if (!this._vadStarted && this._vadEnabled) {
+      this.logger.debug('_startVad');
+      this.addCustomEventListener(this.ep, VadDetection.Detection, this._onVadDetected.bind(this, this.cs, this.ep));
+      this.ep?.startVadDetection(this.vad);
+      this._vadStarted = true;
+    }
+  }
+
+  _stopVad() {
+    if (this._vadStarted) {
+      this.logger.debug('_stopVad');
+      this.ep?.stopVadDetection(this.vad);
+      this.ep?.removeCustomEventListener(VadDetection.Detection, this._onVadDetected);
+      this._vadStarted = false;
+    }
+  }
+
   _startFillerNoise() {
     this.logger.debug('Gather:_startFillerNoise - playing filler noise');
     this.ep?.play(this.fillerNoise.url);
@@ -1039,6 +1062,10 @@ class TaskGather extends SttTask {
       this._killAudio(cs);
       this.emit('vad');
     }
+    if (this.vad?.strategy === 'one-shot') {
+      this.ep?.removeCustomEventListener(VadDetection.Detection, this._onVadDetected);
+      this._vadStarted = false;
+    }
   }
 
   _onNoSpeechDetected(cs, ep, evt, fsEvent) {