Continuos ASR for transcribe (#398)

* asrTimeout

* fix jslint

* change log

* fix interrim

lib/tasks/transcribe.js

@@ -1,4 +1,5 @@
 const Task = require('./task');
+const assert = require('assert');
 const {
   TaskName,
   TaskPreconditions,
@@ -56,6 +57,12 @@ class TaskTranscribe extends Task {
     this._sonioxTranscripts = [];
 
     this.childSpan = [null, null];
+
+    // Continuos asr timeout
+    this.asrTimeout = typeof this.data.recognizer.asrTimeout === 'number' ? this.data.recognizer.asrTimeout * 1000 : 0;
+    this.isContinuousAsr = this.asrTimeout > 0;
+    /* buffer speech for continuous asr */
+    this._bufferedTranscripts = [];
   }
 
   get name() { return TaskName.Transcribe; }
@@ -308,6 +315,26 @@ class TaskTranscribe extends Task {
       }
     }
 
+    if (this.isContinuousAsr && evt.is_final) {
+      this._bufferedTranscripts.push(evt);
+      this._startAsrTimer(channel);
+    } else {
+      await this._resolve(channel, evt);
+    }
+  }
+
+  _compileTranscripts() {
+    assert(this._bufferedTranscripts.length);
+    const evt = this._bufferedTranscripts[0];
+    let t = '';
+    for (const a of this._bufferedTranscripts) {
+      t += ` ${a.alternatives[0].transcript}`;
+    }
+    evt.alternatives[0].transcript = t.trim();
+    return evt;
+  }
+
+  async _resolve(channel, evt) {
     /* we've got a transcript, so end the otel child span for this channel */
     if (this.childSpan[channel - 1] && this.childSpan[channel - 1].span) {
       this.childSpan[channel - 1].span.setAttributes({
@@ -485,7 +512,22 @@ class TaskTranscribe extends Task {
     this.notifyError({msg: 'ASR error', details:`Custom speech vendor ${this.vendor} error: ${evt.error}`});
   }
 
+  _startAsrTimer(channel) {
+    assert(this.isContinuousAsr);
+    this._clearAsrTimer(channel);
+    this._asrTimer = setTimeout(() => {
+      this.logger.debug(`TaskTranscribe:_startAsrTimer - asr timer went off for channel: ${channel}`);
+      const evt = this._compileTranscripts();
+      this._bufferedTranscripts = [];
+      this._resolve(channel, evt);
+    }, this.asrTimeout);
+    this.logger.debug(`TaskTranscribe:_startAsrTimer: set for ${this.asrTimeout}ms for channel ${channel}`);
+  }
 
+  _clearAsrTimer(channel) {
+    if (this._asrTimer) clearTimeout(this._asrTimer);
+    this._asrTimer = null;
+  }
 }
 
 module.exports = TaskTranscribe;

test/transcribe-tests.js

@@ -217,3 +217,41 @@ test('\'transcribe\' test - soniox', async(t) => {
     t.error(err);
   }
 });
+
+test('\'transcribe\' test - google with asrTimeout', async(t) => {
+  if (!GCP_JSON_KEY) {
+    t.pass('skipping google tests');
+    return t.end();
+  }
+  clearModule.all();
+  const {srf, disconnect} = require('../app');
+
+  try {
+    await connect(srf);
+    // GIVEN
+    let verbs = [
+      {
+        "verb": "transcribe",
+        "recognizer": {
+          "vendor": "google",
+          "hints": ["customer support", "sales", "human resources", "HR"],
+          "asrTimeout": 4
+        },
+        "transcriptionHook": "/transcriptionHook"
+      }
+    ];
+    let from = "gather_success";
+    await provisionCallHook(from, verbs);
+    // THEN
+    await sippUac('uac-gather-account-creds-success.xml', '172.38.0.10', from);
+    let obj = await getJSON(`http://127.0.0.1:3100/lastRequest/${from}_actionHook`);
+    t.ok(obj.body.speech.alternatives[0].transcript.toLowerCase().startsWith('i\'d like to speak to customer support'),
+      'transcribe: succeeds when using google credentials');
+
+    disconnect();
+  } catch (err) {
+    console.log(`error received: ${err}`);
+    disconnect();
+    t.error(err);
+  }
+});