watson-speech
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IBM Watson Speech to Text and Text to Speech SDK for web browsers.
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<title>JSDoc: Source: speech-to-text/file-player.js</title>
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<h1 class="page-title">Source: speech-to-text/file-player.js</h1>
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<pre class="prettyprint source linenums"><code>'use strict';
var getContentTypeFromHeader = require('./content-type');
/**
* Plays audio from a URL
* Compatible with Mobile Safari if triggered in direct response to a user interaction (e.g. click)
* @param {String} url
* @constructor
*/
function UrlPlayer(url) {
var audio = this.audio = new Audio();
audio.src = url;
audio.play();
/**
* Stops the audio
*/
this.stop = function stop() {
audio.pause();
audio.currentTime = 0;
};
}
/**
* Plays audio from File/Blob instances
* @param {File|Blob} file
* @param {String} contentType
* @constructor
*/
function FilePlayer(file, contentType) {
var audio = this.audio = new Audio();
if (audio.canPlayType(contentType)) {
audio.src = URL.createObjectURL(new Blob([file], { type: contentType }));
audio.play();
} else {
// if we emit an error, it prevents the promise from returning the actual result
// however, most browsers do not support flac, so this is a reasonably scenario
var err = new Error('Current browser is unable to play back ' + contentType);
err.name = FilePlayer.ERROR_UNSUPPORTED_FORMAT;
err.contentType = contentType;
throw err;
}
/**
* Stops the audio
*/
this.stop = function stop() {
audio.pause();
audio.currentTime = 0;
};
}
FilePlayer.ERROR_UNSUPPORTED_FORMAT = 'UNSUPPORTED_FORMAT';
/**
* Reads the first few bytes of a binary file and resolves to the content-type if recognized & supported
* @param {File|Blob} file
* @return {Promise}
*/
function getContentTypeFromFile(file) {
return new Promise(function(resolve, reject) {
var blobToText = new Blob([file]).slice(0, 4);
var r = new FileReader();
r.readAsText(blobToText);
r.onload = function() {
var ct = getContentTypeFromHeader(r.result);
if (ct) {
resolve(ct);
} else {
var err = new Error('Unable to determine content type from file header; only wav, flac, and ogg/opus are supported.');
err.name = FilePlayer.ERROR_UNSUPPORTED_FORMAT;
reject(err);
}
};
});
}
/**
* Determines the file's content-type and then resolves to a FilePlayer instance
* @param {File|Blob|String} file - binary data or URL of audio file (binary data playback may not work on mobile Safari)
* @return {Promise.<FilePlayer>}
*/
function playFile(file) {
if (typeof file === 'string') {
return Promise.resolve(new UrlPlayer(file));
}
return getContentTypeFromFile(file).then(function(contentType) {
return new FilePlayer(file, contentType);
});
}
module.exports = FilePlayer;
module.exports.getContentType = getContentTypeFromFile;
module.exports.playFile = playFile;
</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="UrlPlayer.html">UrlPlayer</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:data">data</a></li><li><a href="RecognizeStream.html#event:error">error</a></li><li><a href="RecognizeStream.html#event:listening">listening</a></li><li><a href="RecognizeStream.html#event:message">message</a></li><li><a href="RecognizeStream.html#event:open">open</a></li><li><a href="RecognizeStream.html#event:send-data">send-data</a></li><li><a href="RecognizeStream.html#event:send-json">send-json</a></li><li><a href="RecognizeStream.html#event:stop">stop</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#playFile">playFile</a></li></ul>
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Documentation generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 3.4.3</a> on Tue Feb 21 2017 17:41:51 GMT+0000 (UTC)
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