shaka-player
Version:
DASH/EME video player library
88 lines (80 loc) • 2.63 kB
JavaScript
/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
goog.provide('shaka.text.WebVttGenerator');
goog.require('shaka.text.Cue');
goog.require('shaka.text.Utils');
/**
* @summary Manage the conversion to WebVTT.
* @export
*/
shaka.text.WebVttGenerator = class {
/**
* @param {!Array<!shaka.text.Cue>} cues
* @param {!Array<!shaka.extern.AdCuePoint>} adCuePoints
* @return {string}
*/
static convert(cues, adCuePoints) {
const webvttTimeString = (time) => {
let newTime = time;
for (const adCuePoint of adCuePoints) {
if (adCuePoint.end && adCuePoint.start < time) {
const offset = adCuePoint.end - adCuePoint.start;
newTime += offset;
}
}
const hours = Math.floor(newTime / 3600);
const minutes = Math.floor(newTime / 60 % 60);
const seconds = Math.floor(newTime % 60);
const milliseconds = Math.floor(newTime * 1000 % 1000);
return (hours < 10 ? '0' : '') + hours + ':' +
(minutes < 10 ? '0' : '') + minutes + ':' +
(seconds < 10 ? '0' : '') + seconds + '.' +
(milliseconds < 100 ? (milliseconds < 10 ? '00' : '0') : '') +
milliseconds;
};
const flattenedCues = shaka.text.Utils.getCuesToFlatten(cues);
let webvttString = 'WEBVTT\n\n';
for (const cue of flattenedCues) {
const webvttSettings = (cue) => {
const settings = [];
const Cue = shaka.text.Cue;
switch (cue.textAlign) {
case Cue.textAlign.LEFT:
settings.push('align:left');
break;
case Cue.textAlign.RIGHT:
settings.push('align:right');
break;
case Cue.textAlign.CENTER:
settings.push('align:middle');
break;
case Cue.textAlign.START:
settings.push('align:start');
break;
case Cue.textAlign.END:
settings.push('align:end');
break;
}
switch (cue.writingMode) {
case Cue.writingMode.VERTICAL_LEFT_TO_RIGHT:
settings.push('vertical:lr');
break;
case Cue.writingMode.VERTICAL_RIGHT_TO_LEFT:
settings.push('vertical:rl');
break;
}
if (settings.length) {
return ' ' + settings.join(' ');
}
return '';
};
webvttString += webvttTimeString(cue.startTime) + ' --> ' +
webvttTimeString(cue.endTime) + webvttSettings(cue) + '\n';
webvttString += cue.payload + '\n\n';
}
return webvttString;
}
};