/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
goog.provide('shaka.text.LrcTextParser');
goog.require('goog.asserts');
goog.require('shaka.log');
goog.require('shaka.text.Cue');
goog.require('shaka.text.TextEngine');
goog.require('shaka.util.StringUtils');
/**
* LRC file format: https://en.wikipedia.org/wiki/LRC_(file_format)
*
* @implements {shaka.extern.TextParser}
* @export
*/
shaka.text.LrcTextParser = class {
/**
* @override
* @export
*/
parseInit(data) {
goog.asserts.assert(false, 'LRC does not have init segments');
}
/**
* @override
* @export
*/
setSequenceMode(sequenceMode) {
// Unused.
}
/**
* @override
* @export
*/
setManifestType(manifestType) {
// Unused.
}
/**
* @override
* @export
*/
parseMedia(data, time) {
const StringUtils = shaka.util.StringUtils;
const LrcTextParser = shaka.text.LrcTextParser;
// Get the input as a string.
const str = StringUtils.fromUTF8(data);
/** @type {shaka.text.Cue} */
let prevCue = null;
/** @type {!Array.<!shaka.text.Cue>} */
const cues = [];
const lines = str.split(/\r?\n/);
for (const line of lines) {
if (!line || /^\s+$/.test(line)) {
continue;
}
// LRC content
const match = LrcTextParser.lyricLine_.exec(line);
if (match) {
const startTime = LrcTextParser.parseTime_(match[1]);
// This time can be overwritten by a subsequent cue.
// By default we add 2 seconds of duration.
const endTime = time.segmentEnd ? time.segmentEnd : startTime + 2;
const payload = match[2];
const cue = new shaka.text.Cue(startTime, endTime, payload);
// Update previous
if (prevCue) {
prevCue.endTime = startTime;
cues.push(prevCue);
}
prevCue = cue;
continue;
}
shaka.log.warning('LrcTextParser encountered an unknown line.', line);
}
if (prevCue) {
cues.push(prevCue);
}
return cues;
}
/**
* Parses a LRC time from the given parser.
*
* @param {string} string
* @return {number}
* @private
*/
static parseTime_(string) {
const LrcTextParser = shaka.text.LrcTextParser;
const match = LrcTextParser.timeFormat_.exec(string);
const minutes = parseInt(match[1], 10);
const seconds = parseFloat(match[2].replace(',', '.'));
return minutes * 60 + seconds;
}
};
/**
* @const
* @private {!RegExp}
* @example [00:12.0]Text or [00:12.00]Text or [00:12.000]Text or
* [00:12,0]Text or [00:12,00]Text or [00:12,000]Text
*/
shaka.text.LrcTextParser.lyricLine_ =
/^\[(\d{1,2}:\d{1,2}(?:[.,]\d{1,3})?)\](.*)/;
/**
* @const
* @private {!RegExp}
* @example 00:12.0 or 00:12.00 or 00:12.000 or
* 00:12,0 or 00:12,00 or 00:12,000
*/
shaka.text.LrcTextParser.timeFormat_ =
/^(\d+):(\d{1,2}(?:[.,]\d{1,3})?)$/;
shaka.text.TextEngine.registerParser(
'application/x-subtitle-lrc', () => new shaka.text.LrcTextParser());