enabled synchronizing of timing stream to streamed audio start

Author: nfriedly

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+### v0.29.1
+* Added setStartTime() method to TimingStream to facilitate syncing wit when files loaded via URL actually begin playing
+* Updated recognizeFile() to automatically sync timing stream to playback
+
 ### v0.29.0
 * BREAKING: recognizeFile()'s data option renamed to file
 * File option may be a string URL. This enables streaming transcription/playback and mobile Safari support.

dist/watson-speech.js

@@ -134,12 +134,21 @@ module.exports = function recognizeFile(options) { // eslint-disable-line comple
   }
 
   if (options.play) {
-    // todo: if realtime is set, update the realtime stream's start time to match
     // when file playback actually begins
     // (mostly important for downloaded files)
     FilePlayer.playFile(options.file).then(function(player) {
       recognizeStream.on('stop', player.stop.bind(player));
       recognizeStream.on('error', player.stop.bind(player));
+
+      // for files loaded via URL, restet the start time of the timing stream to when it begins playing
+      if (timingStream && typeof options.file === 'string') {
+        // eslint-disable-next-line func-style
+        var fn = function() {
+          timingStream.setStartTime(); // defaults to Date.now()
+          player.audio.removeEventListener('playing', fn);
+        };
+        player.audio.addEventListener('playing', fn);
+      }
     }).catch(function(err) {
 
       // Node.js automatically unpipes any source stream(s) when an error is emitted (on the assumption that the previous stream's output caused the error.)

speech-to-text/recognize-file.js

@@ -68,6 +68,8 @@ TimingStream.prototype._transform = function(msg, encoding, next) {
   }
 };
 
+
+
 /**
  * Grabs the appropriate timestamp from the given message, depending on options.emitAt and the type of message
  *
@@ -107,6 +109,17 @@ TimingStream.prototype.getDelayMs = function(msg) {
   return Math.max(0, delayMs); // never return a negative number
 };
 
+/**
+ * Overrides the start time, adjusting the delay applied to all pending results.
+ *
+ * Stream may emit up to 1 more result based on the older time after this is called.
+ *
+ * @param {Number} [time=Date.now()] Start time in Miliseconds since epoch
+ */
+TimingStream.prototype.setStartTime = function(time) {
+  this.startTime = time || Date.now();
+};
+
 TimingStream.prototype.promise = require('./to-promise');
 
 // when stop is called, immediately stop emitting results