added speakerlessInterim option to speaker stream

Author: nfriedly

speech-to-text/speaker-stream.js

@@ -36,10 +36,12 @@ var noTimestamps = require('./no-timestamps');
  *
  * @constructor
  * @param {Object} options
+ * @param {boolean} [options.speakerlessInterim=false] - emit interim results before initial speaker has been identified (allows UI to update more quickly)
  */
 function SpeakerStream(options) {
   options = options || {};
   options.objectMode = true;
+  this.options = options;
   Transform.call(this, options);
   /**
    * timestamps is a 2-d array.
@@ -80,7 +82,6 @@ function SpeakerStream(options) {
    * @private
    */
   this.speaker_labels = [];
-
 }
 util.inherits(SpeakerStream, Transform);
 
@@ -96,8 +97,11 @@ var TO = 2;
 
 SpeakerStream.ERROR_MISMATCH = 'MISMATCH';
 
-
-SpeakerStream.prototype.process = function() {
+/**
+ * Builds a results object with everything we've got so far
+ * @returns {*}
+ */
+SpeakerStream.prototype.buildMessage = function() {
   var final = this.isFinal();
   var errored = false;
 
@@ -153,18 +157,8 @@ SpeakerStream.prototype.process = function() {
     return arr;
   }, []);
 
-  if (results.length) {
-    /**
-     * Emit an object similar to the normal results object, only with multiple entries in the results Array (a new one
-     * each time the speaker changes), and with a speaker field on the results.
-     *
-     * result_index is always 0 because the results always includes the entire conversation so far.
-     *
-     * @event SpeakerStream#data
-     * @param {Object} results-format message with multiple results and an extra speaker field on each result
-     */
-    this.push({results: results, result_index: 0});
-  }
+  // result_index is always 0 because the results always includes the entire conversation so far.
+  return {results: results, result_index: 0};
 };
 
 /**
@@ -219,12 +213,29 @@ SpeakerStream.prototype.handleSpeakerLabels = function(data) {
 };
 
 SpeakerStream.prototype._transform = function(data, encoding, next) {
+  var message;
   if (Array.isArray(data.results)) {
     this.handleResults(data);
+    if (this.options.speakerlessInterim && data.results.length && data.results[0].final === false) {
+      message = this.buildMessage();
+      message.results = message.results.concat(data.results);
+    }
   }
   if (Array.isArray(data.speaker_labels)) {
     this.handleSpeakerLabels(data);
-    this.process();
+    message = this.buildMessage();
+  }
+  if (message) {
+    /**
+     * Emit an object similar to the normal results object, only with multiple entries in the results Array (a new one
+     * each time the speaker changes), and with a speaker field on the results.
+     *
+     * result_index is always 0 because the results always includes the entire conversation so far.
+     *
+     * @event SpeakerStream#data
+     * @param {Object} results-format message with multiple results and an extra speaker field on each result
+     */
+    this.push(message);
   }
   next();
 };
@@ -241,7 +252,8 @@ SpeakerStream.prototype._flush = function(done) {
     if (this.timestamps.length && !this.speaker_labels.length) {
       msg = 'No speaker_labels found. SpeakerStream requires speaker_labels to be enabled.';
     } else {
-      msg = 'Mismatch between number of word timestamps (' + this.timestamps.length + ') and number of speaker_labels (' + this.speaker_labels.length + ') - some data may be lost.';
+      msg = 'Mismatch between number of word timestamps (' + this.timestamps.length + ') and number of speaker_labels (' +
+        this.speaker_labels.length + ') - some data may be lost.';
     }
     var err = new Error(msg);
     err.name = SpeakerStream.ERROR_MISMATCH;

test/speaker-stream-spec.js

@@ -291,6 +291,96 @@ describe('SpeakerStream', function() {
   });
 
 
+  it('should provide early results when options.speakerlessInterim=true', function(done) {
+    var stream = new SpeakerStream({speakerlessInterim: true});
+    stream.on('error', done);
+    var actual = [];
+    stream.on('data', function(data) {
+      actual.push(data);
+    });
+
+    var expected = [{
+      results: [{
+        alternatives: [{
+          timestamps: [
+            ['hi', 0.06, 0.28],
+          ],
+          transcript: 'hi '
+        }],
+        final: false
+      }],
+      result_index: 0
+    }, {
+      results: [{
+        speaker: 0,
+        alternatives: [{
+          timestamps: [
+            ['hi', 0.06, 0.28],
+          ],
+          transcript: 'hi '
+        }],
+        final: true
+      },
+        {
+          speaker: 1,
+          alternatives: [{
+            timestamps: [
+              ['hello', 0.28, 0.37],
+            ],
+            transcript: 'hello '
+          }],
+          final: true
+        }],
+      result_index: 0
+    }];
+
+    stream.on('end', function() {
+      assert.deepEqual(actual, expected);
+      done();
+    });
+
+    stream.write({
+      results: [{
+        alternatives: [{
+          timestamps: [
+            ['hi', 0.06, 0.28],
+          ],
+          transcript: 'hi '
+        }],
+        final: false
+      }],
+      result_index: 0
+    });
+    stream.write({
+      results: [{
+        alternatives: [{
+          timestamps: [
+            ['hi', 0.06, 0.28],
+            ['hello', 0.28, 0.37],
+          ],
+          transcript: 'hi hello '
+        }],
+        final: true
+      }],
+      result_index: 0
+    });
+    stream.end({
+      speaker_labels: [{
+        from: 0.06,
+        to: 0.28,
+        speaker: 0,
+        confidence: 0.512,
+        final: false
+      }, {
+        from: 0.28,
+        to: 0.37,
+        speaker: 1,
+        confidence: 0.512,
+        final: true
+      }]
+    });
+  });
+
   describe('speakerLabelsSorter', function() {
     it('should correctly sort speaker labels by start time and then by end time', function() {
       var input = [