watson-speech
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IBM Watson Speech to Text and Text to Speech SDK for web browsers.
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<h1 class="page-title">Source: speech-to-text/speaker-stream.js</h1>
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<pre class="prettyprint source linenums"><code>/**
* Copyright 2014 IBM Corp. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
var Transform = require('stream').Transform;
var util = require('util');
var pullAllWith = require('lodash.pullallwith');
var noTimestamps = require('./no-timestamps');
/**
* Object-Mode stream that splits up results by speaker.
*
* Output format is similar to existing results formats, but with an extra speaker field,
*
* Output results array will usually contain multiple results.
* All results are interim until the final batch; the text will not change, but the speaker may, and so the text may move from one interim result to another.
*
* Note: when combined with a TimingStream, data events may contain a combination of final and interim results (with the last one sometimes being interim)
*
* Ignores interim results from the service.
*
* @constructor
* @param {Object} options
*/
function SpeakerStream(options) {
options = options || {};
options.objectMode = true;
Transform.call(this, options);
/**
* timestamps is a 2-d array.
* The sub-array is [word, from time, to time]
* Example:
* [
["Yes", 28.92, 29.17],
["that's", 29.17, 29.37],
["right", 29.37, 29.64]
]
* @type {Array<Array>}
* @private
*/
this.timestamps = [];
/**
* speaker_labels is an array of objects.
* Example:
* [{
"from": 28.92,
"to": 29.17,
"speaker": 1,
"confidence": 0.641,
"final": false
}, {
"from": 29.17,
"to": 29.37,
"speaker": 1,
"confidence": 0.641,
"final": false
}, {
"from": 29.37,
"to": 29.64,
"speaker": 1,
"confidence": 0.641,
"final": false
}]
* @type {Array<Object>}
* @private
*/
this.speaker_labels = [];
}
util.inherits(SpeakerStream, Transform);
SpeakerStream.prototype.isFinal = function() {
return this.speaker_labels.length && this.speaker_labels[this.speaker_labels.length - 1].final;
};
// positions in the timestamps 2d array
var WORD = 0;
var FROM = 1;
var TO = 2;
SpeakerStream.ERROR_MISMATCH = 'MISMATCH';
SpeakerStream.prototype.process = function() {
var final = this.isFinal();
var errored = false;
// assumes that each speaker_label will have a matching word timestamp at the same index
// stops processing and emits an error if this assumption is violated
var pairs = this.speaker_labels.map(function(label, i) {
var timestamp = this.timestamps[i];
if (!timestamp || timestamp[FROM] !== label.from || timestamp[TO] !== label.to) {
if (!errored) {
var err = new Error('Mismatch between speaker_label and word timestamp');
err.name = SpeakerStream.ERROR_MISMATCH;
err.speaker_label = label;
err.timestamp = timestamp;
err.speaker_labels = this.speaker_labels;
err.timestamps = this.timestamps;
this.emit('error', err);
errored = true;
}
return null;
}
return [timestamp, label];
}, this);
if (errored) {
return;
}
var results = pairs.reduce(function(arr, pair) {
// this turns our pairs into something that looks like a regular results object, only with a speaker field
// each result represents a single "line" from a particular speaker
// todo: consider also splitting results up at pauses (where they are split when they arrive from the service) - FormatStream helps here
var currentResult = arr[arr.length - 1];
if (!currentResult || currentResult.speaker !== pair[1].speaker) {
// new speaker - start a new result
// todo: consider trying to include word alternatives and other features in these results
currentResult = {
speaker: pair[1].speaker,
alternatives: [{
transcript: pair[0][WORD] + ' ',
timestamps: [
pair[0]
]
}],
final: final
};
// and add it to the list
arr.push(currentResult);
} else {
// otherwise just append the current word to the current result
currentResult.alternatives[0].transcript += pair[0][WORD] + ' ';
currentResult.alternatives[0].timestamps.push(pair[0]);
}
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});
}
};
/**
* Captures the timestamps out of results or errors if timestamps are missing
* @param {Object} data
*/
SpeakerStream.prototype.handleResults = function(data) {
if (noTimestamps(data)) {
var err = new Error('SpeakerStream requires that timestamps and speaker_labels be enabled');
err.name = noTimestamps.ERROR_NO_TIMESTAMPS;
this.emit('error', err);
return;
}
data.results.filter(function(result) {
return result.final;
}).forEach(function(result) {
this.timestamps = this.timestamps.concat(result.alternatives[0].timestamps);
}, this);
};
// sorts by start time and then end time and then finality
SpeakerStream.speakerLabelsSorter = function(a, b) {
if (a.from === b.from) {
if (a.to === b.to) {
return 0;
}
return a.to < b.to ? -1 : 1;
}
return a.from < b.from ? -1 : 1;
};
/**
* Only the very last labeled word gets final: true. Up until that point, all speaker_labels are considered interim and
* may be repeated with a new speaker selected in a later set of speaker_labels.
*
* @private
* @param {Object} data
*/
SpeakerStream.prototype.handleSpeakerLabels = function(data) {
var speaker_labels = data.speaker_labels; // eslint-disable-line camelcase
// remove any values from the old speaker_labels that are duplicated in the new set
pullAllWith(this.speaker_labels, speaker_labels, function(old, nw) {
return old.from === nw.from && old.to === nw.to;
});
// next append the new labels to the remaining old ones
this.speaker_labels.push.apply(this.speaker_labels, data.speaker_labels);
// finally, ensure the list is still sorted chronologically
this.speaker_labels.sort(SpeakerStream.speakerLabelsSorter);
};
SpeakerStream.prototype._transform = function(data, encoding, next) {
if (Array.isArray(data.results)) {
this.handleResults(data);
}
if (Array.isArray(data.speaker_labels)) {
this.handleSpeakerLabels(data);
this.process();
}
next();
};
/**
* catches cases where speaker_labels was not enabled and internal errors that cause data loss
*
* @param {Function} done
* @private
*/
SpeakerStream.prototype._flush = function(done) {
if (this.timestamps.length !== this.speaker_labels.length) {
var msg;
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.';
}
var err = new Error(msg);
err.name = SpeakerStream.ERROR_MISMATCH;
err.speaker_labels = this.speaker_labels;
err.timestamps = this.timestamps;
this.emit('error', err);
}
done();
};
SpeakerStream.prototype.promise = require('./to-promise');
module.exports = SpeakerStream;
</code></pre>
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<h2><a href="index.html">Home</a></h2><h3>Modules</h3><ul><li><a href="module-watson-speech.html">watson-speech</a></li><li><a href="module-watson-speech_speech-to-text.html">watson-speech/speech-to-text</a></li><li><a href="module-watson-speech_speech-to-text_get-models.html">watson-speech/speech-to-text/get-models</a></li><li><a href="module-watson-speech_speech-to-text_recognize-file.html">watson-speech/speech-to-text/recognize-file</a></li><li><a href="module-watson-speech_speech-to-text_recognize-microphone.html">watson-speech/speech-to-text/recognize-microphone</a></li><li><a href="module-watson-speech_text-to-speech.html">watson-speech/text-to-speech</a></li><li><a href="module-watson-speech_text-to-speech_get-voices.html">watson-speech/text-to-speech/get-voices</a></li><li><a href="module-watson-speech_text-to-speech_synthesize.html">watson-speech/text-to-speech/synthesize</a></li></ul><h3>Classes</h3><ul><li><a href="FilePlayer.html">FilePlayer</a></li><li><a href="FormatStream.html">FormatStream</a></li><li><a href="RecognizeStream.html">RecognizeStream</a></li><li><a href="ResultStream.html">ResultStream</a></li><li><a href="SpeakerStream.html">SpeakerStream</a></li><li><a href="TimingStream.html">TimingStream</a></li><li><a href="WebAudioL16Stream.html">WebAudioL16Stream</a></li><li><a href="WritableElementStream.html">WritableElementStream</a></li></ul><h3>Events</h3><ul><li><a href="RecognizeStream.html#event:close">close</a></li><li><a href="RecognizeStream.html#event:connection-close">connection-close</a></li><li><a href="RecognizeStream.html#event:data">data</a></li><li><a href="RecognizeStream.html#event:error">error</a></li><li><a href="RecognizeStream.html#event:send-json">send-json</a></li><li><a href="SpeakerStream.html#event:data">data</a></li></ul><h3>Global</h3><ul><li><a href="global.html#getContentTypeFromFile">getContentTypeFromFile</a></li><li><a href="global.html#getEnd">getEnd</a></li><li><a href="global.html#playFile">playFile</a></li></ul>
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