mirror of
https://github.com/shaka-project/shaka-player.git
synced 2026-06-14 15:56:38 +03:00
Álvaro Velad Galván
1009 lines
30 KiB
JavaScript
1009 lines
30 KiB
JavaScript
/*! @license
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* Shaka Player
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* Copyright 2016 Google LLC
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* SPDX-License-Identifier: Apache-2.0
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*/
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goog.provide('shaka.text.VttTextParser');
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goog.require('goog.asserts');
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goog.require('shaka.log');
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goog.require('shaka.text.Cue');
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goog.require('shaka.text.CueRegion');
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goog.require('shaka.text.TextEngine');
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goog.require('shaka.util.Error');
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goog.require('shaka.util.StringUtils');
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goog.require('shaka.util.TextParser');
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goog.require('shaka.util.XmlUtils');
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/**
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* @implements {shaka.extern.TextParser}
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* @export
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*/
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shaka.text.VttTextParser = class {
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/** Constructs a VTT parser. */
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constructor() {
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/** @private {boolean} */
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this.sequenceMode_ = false;
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}
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/**
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* @override
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* @export
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*/
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parseInit(data) {
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goog.asserts.assert(false, 'VTT does not have init segments');
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}
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/**
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* @override
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* @export
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*/
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setSequenceMode(sequenceMode) {
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this.sequenceMode_ = sequenceMode;
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}
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/**
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* @override
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* @export
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*/
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parseMedia(data, time) {
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const VttTextParser = shaka.text.VttTextParser;
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// Get the input as a string. Normalize newlines to \n.
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let str = shaka.util.StringUtils.fromUTF8(data);
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str = str.replace(/\r\n|\r(?=[^\n]|$)/gm, '\n');
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const blocks = str.split(/\n{2,}/m);
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if (!/^WEBVTT($|[ \t\n])/m.test(blocks[0])) {
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throw new shaka.util.Error(
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shaka.util.Error.Severity.CRITICAL,
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shaka.util.Error.Category.TEXT,
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shaka.util.Error.Code.INVALID_TEXT_HEADER);
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}
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// Depending on "segmentRelativeVttTiming" configuration,
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// "vttOffset" will correspond to either "periodStart" (default)
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// or "segmentStart", for segmented VTT where timings are relative
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// to the beginning of each segment.
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// NOTE: "periodStart" is the timestamp offset applied via TextEngine.
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// It is no longer closely tied to periods, but the name stuck around.
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// NOTE: This offset and the flag choosing its meaning have no effect on
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// HLS content, which should use X-TIMESTAMP-MAP and periodStart instead.
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let offset = time.vttOffset;
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// Only use 'X-TIMESTAMP-MAP' in sequence mode, as that is currently
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// shorthand for HLS. Note that an offset based on the first video
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// timestamp has already been extracted, and appears in periodStart.
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// The relative offset from X-TIMESTAMP-MAP will be added to that for HLS.
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if (blocks[0].includes('X-TIMESTAMP-MAP') && this.sequenceMode_) {
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// https://bit.ly/2K92l7y
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// The 'X-TIMESTAMP-MAP' header is used in HLS to align text with
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// the rest of the media.
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// The header format is 'X-TIMESTAMP-MAP=MPEGTS:n,LOCAL:m'
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// (the attributes can go in any order)
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// where n is MPEG-2 time and m is cue time it maps to.
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// For example 'X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000'
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// means an offset of 10 seconds
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// 900000/MPEG_TIMESCALE - cue time.
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const cueTimeMatch =
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blocks[0].match(/LOCAL:((?:(\d{1,}):)?(\d{2}):(\d{2})\.(\d{3}))/m);
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const mpegTimeMatch = blocks[0].match(/MPEGTS:(\d+)/m);
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if (cueTimeMatch && mpegTimeMatch) {
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const parser = new shaka.util.TextParser(cueTimeMatch[1]);
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const cueTime = shaka.text.VttTextParser.parseTime_(parser);
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if (cueTime == null) {
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throw new shaka.util.Error(
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shaka.util.Error.Severity.CRITICAL,
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shaka.util.Error.Category.TEXT,
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shaka.util.Error.Code.INVALID_TEXT_HEADER);
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}
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let mpegTime = Number(mpegTimeMatch[1]);
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const mpegTimescale = shaka.text.VttTextParser.MPEG_TIMESCALE_;
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const rolloverSeconds =
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shaka.text.VttTextParser.TS_ROLLOVER_ / mpegTimescale;
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let segmentStart = time.segmentStart - time.periodStart;
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while (segmentStart >= rolloverSeconds) {
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segmentStart -= rolloverSeconds;
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mpegTime += shaka.text.VttTextParser.TS_ROLLOVER_;
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}
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offset = time.periodStart + mpegTime / mpegTimescale - cueTime;
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}
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}
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// Parse VTT regions.
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/* !Array.<!shaka.extern.CueRegion> */
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const regions = [];
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for (const line of blocks[0].split('\n')) {
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if (/^Region:/.test(line)) {
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const region = VttTextParser.parseRegion_(line);
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regions.push(region);
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}
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}
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/** @type {!Map.<string, shaka.text.Cue>} */
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const styles = new Map();
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VttTextParser.addDefaultTextColor_(styles);
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// Parse cues.
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const ret = [];
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for (const block of blocks.slice(1)) {
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const lines = block.split('\n');
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VttTextParser.parseStyle_(lines, styles);
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const cue = VttTextParser.parseCue_(lines, offset, regions, styles);
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if (cue) {
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ret.push(cue);
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}
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}
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return ret;
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}
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/**
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* Add default color
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*
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* @param {!Map.<string, shaka.text.Cue>} styles
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* @private
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*/
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static addDefaultTextColor_(styles) {
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const textColor = shaka.text.Cue.defaultTextColor;
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for (const [key, value] of Object.entries(textColor)) {
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const cue = new shaka.text.Cue(0, 0, '');
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cue.color = value;
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styles.set('.' + key, cue);
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}
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const bgColor = shaka.text.Cue.defaultTextBackgroundColor;
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for (const [key, value] of Object.entries(bgColor)) {
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const cue = new shaka.text.Cue(0, 0, '');
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cue.backgroundColor = value;
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styles.set('.' + key, cue);
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}
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}
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/**
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* Parses a string into a Region object.
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*
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* @param {string} text
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* @return {!shaka.extern.CueRegion}
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* @private
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*/
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static parseRegion_(text) {
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const VttTextParser = shaka.text.VttTextParser;
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const parser = new shaka.util.TextParser(text);
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// The region string looks like this:
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// Region: id=fred width=50% lines=3 regionanchor=0%,100%
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// viewportanchor=10%,90% scroll=up
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const region = new shaka.text.CueRegion();
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// Skip 'Region:'
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parser.readWord();
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parser.skipWhitespace();
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let word = parser.readWord();
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while (word) {
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if (!VttTextParser.parseRegionSetting_(region, word)) {
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shaka.log.warning(
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'VTT parser encountered an invalid VTTRegion setting: ', word,
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' The setting will be ignored.');
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}
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parser.skipWhitespace();
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word = parser.readWord();
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}
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return region;
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}
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/**
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* Parses a style block into a Cue object.
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*
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* @param {!Array.<string>} text
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* @param {!Map.<string, shaka.text.Cue>} styles
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* @private
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*/
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static parseStyle_(text, styles) {
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// Skip empty blocks.
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if (text.length == 1 && !text[0]) {
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return;
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}
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// Skip comment blocks.
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if (/^NOTE($|[ \t])/.test(text[0])) {
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return;
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}
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// Only style block are allowed.
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if (text[0] != 'STYLE') {
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return;
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}
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if (!text[1].includes('::cue')) {
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return;
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}
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let styleSelector = 'global';
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// Look for what is within parentisesis. For example:
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// <code>:: cue (b) {</code>, what we are looking for is <code>b</code>
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const selector = text[1].match(/\((.*)\)/);
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if (selector) {
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styleSelector = selector.pop();
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}
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// We start at 2 to avoid '::cue' and end earlier to avoid '}'
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let propertyLines = text.slice(2, -1);
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if (text[1].includes('}')) {
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const payload = /\{(.*?)\}/.exec(text[1]);
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if (payload) {
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propertyLines = payload[1].split(';');
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}
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}
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const cue = new shaka.text.Cue(0, 0, '');
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let validStyle = false;
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for (let i = 0; i < propertyLines.length; i++) {
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// We look for CSS properties. As a general rule they are separated by
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// <code>:</code>. Eg: <code>color: red;</code>
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const lineParts = /^\s*([^:]+):\s*(.*)/.exec(propertyLines[i]);
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if (lineParts) {
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const name = lineParts[1].trim();
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const value = lineParts[2].trim().replace(';', '');
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switch (name) {
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case 'background-color':
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validStyle = true;
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cue.backgroundColor = value;
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break;
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case 'color':
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validStyle = true;
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cue.color = value;
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break;
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case 'font-family':
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validStyle = true;
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cue.fontFamily = value;
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break;
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case 'font-size':
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validStyle = true;
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cue.fontSize = value;
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break;
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case 'font-weight':
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if (parseInt(value, 10) >= 700) {
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validStyle = true;
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cue.fontWeight = shaka.text.Cue.fontWeight.BOLD;
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}
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break;
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case 'font-style':
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switch (value) {
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case 'normal':
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validStyle = true;
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cue.fontStyle = shaka.text.Cue.fontStyle.NORMAL;
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break;
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case 'italic':
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validStyle = true;
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cue.fontStyle = shaka.text.Cue.fontStyle.ITALIC;
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break;
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case 'oblique':
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validStyle = true;
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cue.fontStyle = shaka.text.Cue.fontStyle.OBLIQUE;
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break;
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}
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break;
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case 'opacity':
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validStyle = true;
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cue.opacity = parseFloat(value);
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break;
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case 'text-shadow':
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validStyle = true;
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cue.textShadow = value;
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break;
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case 'white-space':
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validStyle = true;
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cue.wrapLine = value != 'noWrap';
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break;
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default:
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shaka.log.warning('VTT parser encountered an unsupported style: ',
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lineParts);
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break;
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}
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}
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}
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if (validStyle) {
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styles.set(styleSelector, cue);
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}
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}
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/**
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* Parses a text block into a Cue object.
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*
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* @param {!Array.<string>} text
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* @param {number} timeOffset
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* @param {!Array.<!shaka.extern.CueRegion>} regions
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* @param {!Map.<string, shaka.text.Cue>} styles
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* @return {shaka.text.Cue}
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* @private
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*/
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static parseCue_(text, timeOffset, regions, styles) {
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const VttTextParser = shaka.text.VttTextParser;
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// Skip empty blocks.
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if (text.length == 1 && !text[0]) {
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return null;
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}
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// Skip comment blocks.
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if (/^NOTE($|[ \t])/.test(text[0])) {
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return null;
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}
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// Skip style and region blocks.
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if (text[0] == 'STYLE' || text[0] == 'REGION') {
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return null;
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}
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let id = null;
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if (!text[0].includes('-->')) {
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id = text[0];
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text.splice(0, 1);
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}
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// Parse the times.
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const parser = new shaka.util.TextParser(text[0]);
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let start = VttTextParser.parseTime_(parser);
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const expect = parser.readRegex(/[ \t]+-->[ \t]+/g);
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let end = VttTextParser.parseTime_(parser);
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if (start == null || expect == null || end == null) {
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throw new shaka.util.Error(
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shaka.util.Error.Severity.CRITICAL,
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shaka.util.Error.Category.TEXT,
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shaka.util.Error.Code.INVALID_TEXT_CUE,
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'Could not parse cue time range in WebVTT');
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}
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start += timeOffset;
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end += timeOffset;
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// Get the payload.
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const payload = VttTextParser.htmlUnescape_(
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text.slice(1).join('\n').trim());
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let cue = null;
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if (styles.has('global')) {
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cue = styles.get('global').clone();
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cue.startTime = start;
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cue.endTime = end;
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cue.payload = '';
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} else {
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cue = new shaka.text.Cue(start, end, '');
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}
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VttTextParser.parseCueStyles(payload, cue, styles);
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// Parse optional settings.
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parser.skipWhitespace();
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let word = parser.readWord();
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while (word) {
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if (!VttTextParser.parseCueSetting(cue, word, regions)) {
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shaka.log.warning('VTT parser encountered an invalid VTT setting: ',
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word,
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' The setting will be ignored.');
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}
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parser.skipWhitespace();
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word = parser.readWord();
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}
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if (id != null) {
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cue.id = id;
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}
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return cue;
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}
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/**
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* Parses a WebVTT styles from the given payload.
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*
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* @param {string} payload
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* @param {!shaka.text.Cue} rootCue
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* @param {!Map.<string, shaka.text.Cue>} styles
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*/
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static parseCueStyles(payload, rootCue, styles) {
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const VttTextParser = shaka.text.VttTextParser;
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if (styles.size === 0) {
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VttTextParser.addDefaultTextColor_(styles);
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}
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payload = VttTextParser.replaceColorPayload_(payload);
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payload = VttTextParser.replaceKaraokeStylePayload_(payload);
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payload = VttTextParser.replaceVoiceStylePayload_(payload);
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const xmlPayload = '<span>' + payload + '</span>';
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const element = shaka.util.XmlUtils.parseXmlString(xmlPayload, 'span');
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if (element) {
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/** @type {!Array.<!shaka.extern.Cue>} */
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const cues = [];
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const childNodes = element.childNodes;
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if (childNodes.length == 1) {
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const childNode = childNodes[0];
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if (childNode.nodeType == Node.TEXT_NODE ||
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childNode.nodeType == Node.CDATA_SECTION_NODE) {
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rootCue.payload = payload;
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return;
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}
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}
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for (const childNode of childNodes) {
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VttTextParser.generateCueFromElement_(
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childNode, rootCue, cues, styles);
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}
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rootCue.nestedCues = cues;
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} else {
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shaka.log.warning('The cue\'s markup could not be parsed: ', payload);
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rootCue.payload = payload;
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}
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}
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/**
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* Converts voice style tag to be valid for xml parsing
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* For example,
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* input: <v Shaka>Test
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* output: <v.voice-Shaka>Test</v.voice-Shaka>
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*
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* @param {string} payload
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* @return {string} processed payload
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* @private
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*/
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static replaceVoiceStylePayload_(payload) {
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const voiceTag = 'v';
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const names = [];
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let nameStart = -1;
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let newPayload = '';
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let hasVoiceEndTag = false;
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for (let i = 0; i < payload.length; i++) {
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// This condition is used to manage tags that have end tags.
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if (payload[i] === '/') {
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const end = payload.indexOf('>', i);
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if (end === -1) {
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return payload;
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}
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const tagEnd = payload.substring(i + 1, end);
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if (!tagEnd || tagEnd != voiceTag) {
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newPayload += payload[i];
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continue;
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}
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hasVoiceEndTag = true;
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let tagStart = null;
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if (names.length) {
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tagStart = names[names.length -1];
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}
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if (!tagStart) {
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newPayload += payload[i];
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} else if (tagStart === tagEnd) {
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newPayload += '/' + tagEnd + '>';
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i += tagEnd.length + 1;
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} else {
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if (!tagStart.startsWith(voiceTag)) {
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newPayload += payload[i];
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continue;
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}
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newPayload += '/' + tagStart + '>';
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i += tagEnd.length + 1;
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}
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} else {
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// Here we only want the tag name, not any other payload.
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if (payload[i] === '<') {
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nameStart = i + 1;
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if (payload[nameStart] != voiceTag) {
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nameStart = -1;
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}
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} else if (payload[i] === '>') {
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if (nameStart > 0) {
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names.push(payload.substr(nameStart, i - nameStart));
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nameStart = -1;
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}
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}
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newPayload += payload[i];
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}
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}
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for (const name of names) {
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const newName = name.replace(' ', '.voice-');
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newPayload = newPayload.replace(`<${name}>`, `<${newName}>`);
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newPayload = newPayload.replace(`</${name}>`, `</${newName}>`);
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if (!hasVoiceEndTag) {
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newPayload += `</${newName}>`;
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}
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}
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return newPayload;
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}
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/**
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* Converts karaoke style tag to be valid for xml parsing
|
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* For example,
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* input: Text <00:00:00.450> time <00:00:01.450> 1
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* output: Text <div time="00:00:00.450"> time
|
|
* <div time="00:00:01.450"> 1</div></div>
|
|
*
|
|
* @param {string} payload
|
|
* @return {string} processed payload
|
|
* @private
|
|
*/
|
|
static replaceKaraokeStylePayload_(payload) {
|
|
const names = [];
|
|
let nameStart = -1;
|
|
for (let i = 0; i < payload.length; i++) {
|
|
if (payload[i] === '<') {
|
|
nameStart = i + 1;
|
|
} else if (payload[i] === '>') {
|
|
if (nameStart > 0) {
|
|
const name = payload.substr(nameStart, i - nameStart);
|
|
if (name.match(shaka.text.VttTextParser.timeFormat_)) {
|
|
names.push(name);
|
|
}
|
|
nameStart = -1;
|
|
}
|
|
}
|
|
}
|
|
let newPayload = payload;
|
|
for (const name of names) {
|
|
const replaceTag = '<' + name + '>';
|
|
const startTag = '<div time="' + name + '">';
|
|
const endTag = '</div>';
|
|
newPayload = newPayload.replace(replaceTag, startTag);
|
|
newPayload += endTag;
|
|
}
|
|
return newPayload;
|
|
}
|
|
|
|
/**
|
|
* Converts color end tag to be valid for xml parsing
|
|
* For example,
|
|
* input: <c.yellow.bg_blue>Yellow text on blue bg</c>
|
|
* output: <c.yellow.bg_blue>Yellow text on blue bg</c.yellow.bg_blue>
|
|
*
|
|
* Returns original payload if invalid tag is found.
|
|
* Invalid tag example: <c.yellow><b>Example</c></b>
|
|
*
|
|
* @param {string} payload
|
|
* @return {string} processed payload
|
|
* @private
|
|
*/
|
|
static replaceColorPayload_(payload) {
|
|
const names = [];
|
|
let nameStart = -1;
|
|
let newPayload = '';
|
|
for (let i = 0; i < payload.length; i++) {
|
|
if (payload[i] === '/' && i > 0 && payload[i - 1] === '<') {
|
|
const end = payload.indexOf('>', i);
|
|
if (end <= i) {
|
|
return payload;
|
|
}
|
|
const tagEnd = payload.substring(i + 1, end);
|
|
if (!tagEnd || tagEnd !== 'c') {
|
|
newPayload += payload[i];
|
|
continue;
|
|
}
|
|
const tagStart = names.pop();
|
|
if (!tagStart) {
|
|
newPayload += payload[i];
|
|
} else if (tagStart === tagEnd) {
|
|
newPayload += '/' + tagEnd + '>';
|
|
i += tagEnd.length + 1;
|
|
} else {
|
|
if (!tagStart.startsWith('c.')) {
|
|
newPayload += payload[i];
|
|
continue;
|
|
}
|
|
i += tagEnd.length + 1;
|
|
newPayload += '/' + tagStart + '>';
|
|
}
|
|
} else {
|
|
if (payload[i] === '<') {
|
|
nameStart = i + 1;
|
|
if (payload[nameStart] != 'c') {
|
|
nameStart = -1;
|
|
}
|
|
} else if (payload[i] === '>') {
|
|
if (nameStart > 0) {
|
|
names.push(payload.substr(nameStart, i - nameStart));
|
|
nameStart = -1;
|
|
}
|
|
}
|
|
newPayload += payload[i];
|
|
}
|
|
}
|
|
return newPayload;
|
|
}
|
|
|
|
/**
|
|
* @param {string} value
|
|
* @param {string} defaultValue
|
|
* @private
|
|
*/
|
|
static getOrDefault_(value, defaultValue) {
|
|
if (value && value.length > 0) {
|
|
return value;
|
|
}
|
|
return defaultValue;
|
|
}
|
|
|
|
/**
|
|
* Merges values created in parseStyle_
|
|
* @param {!shaka.extern.Cue} cue
|
|
* @param {shaka.extern.Cue} refCue
|
|
* @private
|
|
*/
|
|
static mergeStyle_(cue, refCue) {
|
|
if (!refCue) {
|
|
return;
|
|
}
|
|
|
|
const VttTextParser = shaka.text.VttTextParser;
|
|
// Overwrites if new value string length > 0
|
|
cue.backgroundColor = VttTextParser.getOrDefault_(
|
|
refCue.backgroundColor, cue.backgroundColor);
|
|
cue.color = VttTextParser.getOrDefault_(
|
|
refCue.color, cue.color);
|
|
cue.fontFamily = VttTextParser.getOrDefault_(
|
|
refCue.fontFamily, cue.fontFamily);
|
|
cue.fontSize = VttTextParser.getOrDefault_(
|
|
refCue.fontSize, cue.fontSize);
|
|
|
|
// Overwrite with new values as unable to determine
|
|
// if new value is set or not
|
|
cue.fontWeight = refCue.fontWeight;
|
|
cue.fontStyle = refCue.fontStyle;
|
|
cue.opacity = refCue.opacity;
|
|
cue.wrapLine = refCue.wrapLine;
|
|
}
|
|
|
|
/**
|
|
* @param {!Node} element
|
|
* @param {!shaka.text.Cue} rootCue
|
|
* @param {Array.<!shaka.extern.Cue>} cues
|
|
* @param {!Map.<string, shaka.text.Cue>} styles
|
|
* @private
|
|
*/
|
|
static generateCueFromElement_(element, rootCue, cues, styles) {
|
|
const VttTextParser = shaka.text.VttTextParser;
|
|
const nestedCue = rootCue.clone();
|
|
if (element.nodeType === Node.ELEMENT_NODE && element.nodeName) {
|
|
const bold = shaka.text.Cue.fontWeight.BOLD;
|
|
const italic = shaka.text.Cue.fontStyle.ITALIC;
|
|
const underline = shaka.text.Cue.textDecoration.UNDERLINE;
|
|
const tags = element.nodeName.split(/(?=[ .])+/g);
|
|
for (const tag of tags) {
|
|
let styleTag = tag;
|
|
// White blanks at start indicate that the style is a voice
|
|
if (styleTag.startsWith('.voice-')) {
|
|
const voice = styleTag.split('-').pop();
|
|
styleTag = `v[voice="${voice}"]`;
|
|
}
|
|
if (styles.has(styleTag)) {
|
|
VttTextParser.mergeStyle_(nestedCue, styles.get(styleTag));
|
|
}
|
|
switch (tag) {
|
|
case 'br': {
|
|
const lineBreakCue = rootCue.clone();
|
|
lineBreakCue.lineBreak = true;
|
|
cues.push(lineBreakCue);
|
|
break;
|
|
}
|
|
case 'b':
|
|
nestedCue.fontWeight = bold;
|
|
break;
|
|
case 'i':
|
|
nestedCue.fontStyle = italic;
|
|
break;
|
|
case 'u':
|
|
nestedCue.textDecoration.push(underline);
|
|
break;
|
|
case 'div': {
|
|
const time = /** @type {!Element} */(element).getAttribute('time');
|
|
if (!time) {
|
|
break;
|
|
}
|
|
const parser = new shaka.util.TextParser(time);
|
|
const cueTime = shaka.text.VttTextParser.parseTime_(parser);
|
|
if (cueTime) {
|
|
nestedCue.startTime = cueTime;
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
const isTextNode = shaka.util.XmlUtils.isText(element);
|
|
if (isTextNode) {
|
|
// Trailing line breaks may lost when convert cue to HTML tag
|
|
// Need to insert line break cue to preserve line breaks
|
|
const textArr = element.textContent.split('\n');
|
|
let isFirst = true;
|
|
for (const text of textArr) {
|
|
if (!isFirst) {
|
|
const lineBreakCue = rootCue.clone();
|
|
lineBreakCue.lineBreak = true;
|
|
cues.push(lineBreakCue);
|
|
}
|
|
if (text.length > 0) {
|
|
const textCue = nestedCue.clone();
|
|
textCue.payload = text;
|
|
cues.push(textCue);
|
|
}
|
|
isFirst = false;
|
|
}
|
|
} else {
|
|
for (const childNode of element.childNodes) {
|
|
VttTextParser.generateCueFromElement_(
|
|
childNode, nestedCue, cues, styles);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Parses a WebVTT setting from the given word.
|
|
*
|
|
* @param {!shaka.text.Cue} cue
|
|
* @param {string} word
|
|
* @param {!Array.<!shaka.text.CueRegion>} regions
|
|
* @return {boolean} True on success.
|
|
*/
|
|
static parseCueSetting(cue, word, regions) {
|
|
const VttTextParser = shaka.text.VttTextParser;
|
|
let results = null;
|
|
if ((results = /^align:(start|middle|center|end|left|right)$/.exec(word))) {
|
|
VttTextParser.setTextAlign_(cue, results[1]);
|
|
} else if ((results = /^vertical:(lr|rl)$/.exec(word))) {
|
|
VttTextParser.setVerticalWritingMode_(cue, results[1]);
|
|
} else if ((results = /^size:([\d.]+)%$/.exec(word))) {
|
|
cue.size = Number(results[1]);
|
|
} else if ((results =
|
|
/^position:([\d.]+)%(?:,(line-left|line-right|center|start|end))?$/
|
|
.exec(word))) {
|
|
cue.position = Number(results[1]);
|
|
if (results[2]) {
|
|
VttTextParser.setPositionAlign_(cue, results[2]);
|
|
}
|
|
} else if ((results = /^region:(.*)$/.exec(word))) {
|
|
const region = VttTextParser.getRegionById_(regions, results[1]);
|
|
if (region) {
|
|
cue.region = region;
|
|
}
|
|
} else {
|
|
return VttTextParser.parsedLineValueAndInterpretation_(cue, word);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
*
|
|
* @param {!Array.<!shaka.text.CueRegion>} regions
|
|
* @param {string} id
|
|
* @return {?shaka.text.CueRegion}
|
|
* @private
|
|
*/
|
|
static getRegionById_(regions, id) {
|
|
const regionsWithId = regions.filter((region) => {
|
|
return region.id == id;
|
|
});
|
|
if (!regionsWithId.length) {
|
|
shaka.log.warning('VTT parser could not find a region with id: ',
|
|
id,
|
|
' The region will be ignored.');
|
|
return null;
|
|
}
|
|
goog.asserts.assert(regionsWithId.length == 1,
|
|
'VTTRegion ids should be unique!');
|
|
|
|
return regionsWithId[0];
|
|
}
|
|
|
|
/**
|
|
* Parses a WebVTTRegion setting from the given word.
|
|
*
|
|
* @param {!shaka.text.CueRegion} region
|
|
* @param {string} word
|
|
* @return {boolean} True on success.
|
|
* @private
|
|
*/
|
|
static parseRegionSetting_(region, word) {
|
|
let results = null;
|
|
if ((results = /^id=(.*)$/.exec(word))) {
|
|
region.id = results[1];
|
|
} else if ((results = /^width=(\d{1,2}|100)%$/.exec(word))) {
|
|
region.width = Number(results[1]);
|
|
} else if ((results = /^lines=(\d+)$/.exec(word))) {
|
|
region.height = Number(results[1]);
|
|
region.heightUnits = shaka.text.CueRegion.units.LINES;
|
|
} else if ((results = /^regionanchor=(\d{1,2}|100)%,(\d{1,2}|100)%$/
|
|
.exec(word))) {
|
|
region.regionAnchorX = Number(results[1]);
|
|
region.regionAnchorY = Number(results[2]);
|
|
} else if ((results = /^viewportanchor=(\d{1,2}|100)%,(\d{1,2}|100)%$/
|
|
.exec(word))) {
|
|
region.viewportAnchorX = Number(results[1]);
|
|
region.viewportAnchorY = Number(results[2]);
|
|
} else if ((results = /^scroll=up$/.exec(word))) {
|
|
region.scroll = shaka.text.CueRegion.scrollMode.UP;
|
|
} else {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* @param {!shaka.text.Cue} cue
|
|
* @param {string} align
|
|
* @private
|
|
*/
|
|
static setTextAlign_(cue, align) {
|
|
const Cue = shaka.text.Cue;
|
|
if (align == 'middle') {
|
|
cue.textAlign = Cue.textAlign.CENTER;
|
|
} else {
|
|
goog.asserts.assert(align.toUpperCase() in Cue.textAlign,
|
|
align.toUpperCase() +
|
|
' Should be in Cue.textAlign values!');
|
|
|
|
cue.textAlign = Cue.textAlign[align.toUpperCase()];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @param {!shaka.text.Cue} cue
|
|
* @param {string} align
|
|
* @private
|
|
*/
|
|
static setPositionAlign_(cue, align) {
|
|
const Cue = shaka.text.Cue;
|
|
if (align == 'line-left' || align == 'start') {
|
|
cue.positionAlign = Cue.positionAlign.LEFT;
|
|
} else if (align == 'line-right' || align == 'end') {
|
|
cue.positionAlign = Cue.positionAlign.RIGHT;
|
|
} else {
|
|
cue.positionAlign = Cue.positionAlign.CENTER;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @param {!shaka.text.Cue} cue
|
|
* @param {string} value
|
|
* @private
|
|
*/
|
|
static setVerticalWritingMode_(cue, value) {
|
|
const Cue = shaka.text.Cue;
|
|
if (value == 'lr') {
|
|
cue.writingMode = Cue.writingMode.VERTICAL_LEFT_TO_RIGHT;
|
|
} else {
|
|
cue.writingMode = Cue.writingMode.VERTICAL_RIGHT_TO_LEFT;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @param {!shaka.text.Cue} cue
|
|
* @param {string} word
|
|
* @return {boolean}
|
|
* @private
|
|
*/
|
|
static parsedLineValueAndInterpretation_(cue, word) {
|
|
const Cue = shaka.text.Cue;
|
|
let results = null;
|
|
if ((results = /^line:([\d.]+)%(?:,(start|end|center))?$/.exec(word))) {
|
|
cue.lineInterpretation = Cue.lineInterpretation.PERCENTAGE;
|
|
cue.line = Number(results[1]);
|
|
if (results[2]) {
|
|
goog.asserts.assert(
|
|
results[2].toUpperCase() in Cue.lineAlign,
|
|
results[2].toUpperCase() + ' Should be in Cue.lineAlign values!');
|
|
cue.lineAlign = Cue.lineAlign[results[2].toUpperCase()];
|
|
}
|
|
} else if ((results =
|
|
/^line:(-?\d+)(?:,(start|end|center))?$/.exec(word))) {
|
|
cue.lineInterpretation = Cue.lineInterpretation.LINE_NUMBER;
|
|
cue.line = Number(results[1]);
|
|
if (results[2]) {
|
|
goog.asserts.assert(
|
|
results[2].toUpperCase() in Cue.lineAlign,
|
|
results[2].toUpperCase() + ' Should be in Cue.lineAlign values!');
|
|
cue.lineAlign = Cue.lineAlign[results[2].toUpperCase()];
|
|
}
|
|
} else {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Parses a WebVTT time from the given parser.
|
|
*
|
|
* @param {!shaka.util.TextParser} parser
|
|
* @return {?number}
|
|
* @private
|
|
*/
|
|
static parseTime_(parser) {
|
|
const results = parser.readRegex(shaka.text.VttTextParser.timeFormat_);
|
|
if (results == null) {
|
|
return null;
|
|
}
|
|
// This capture is optional, but will still be in the array as undefined,
|
|
// in which case it is 0.
|
|
const hours = Number(results[1]) || 0;
|
|
const minutes = Number(results[2]);
|
|
const seconds = Number(results[3]);
|
|
const milliseconds = Number(results[4]);
|
|
if (minutes > 59 || seconds > 59) {
|
|
return null;
|
|
}
|
|
|
|
return (milliseconds / 1000) + seconds + (minutes * 60) + (hours * 3600);
|
|
}
|
|
|
|
/**
|
|
* This method converts the HTML entities &, <, >, ", ',
|
|
* , ‎ and ‏ in string to their corresponding characters.
|
|
*
|
|
* @param {!string} input
|
|
* @return {string}
|
|
* @private
|
|
*/
|
|
static htmlUnescape_(input) {
|
|
// Used to map HTML entities to characters.
|
|
const htmlUnescapes = {
|
|
'&': '&',
|
|
'<': '<',
|
|
'>': '>',
|
|
'"': '"',
|
|
''': '\'',
|
|
' ': '\u{a0}',
|
|
'‎': '\u{200e}',
|
|
'‏': '\u{200f}',
|
|
};
|
|
|
|
// Used to match HTML entities and HTML characters.
|
|
const reEscapedHtml = /&(?:amp|lt|gt|quot|#(0+)?39|nbsp|lrm|rlm);/g;
|
|
const reHasEscapedHtml = RegExp(reEscapedHtml.source);
|
|
// This check is an optimization, since replace always makes a copy
|
|
if (input && reHasEscapedHtml.test(input)) {
|
|
return input.replace(reEscapedHtml, (entity) => {
|
|
// The only thing that might not match the dictionary above is the
|
|
// single quote, which can be matched by many strings in the regex, but
|
|
// only has a single entry in the dictionary.
|
|
return htmlUnescapes[entity] || '\'';
|
|
});
|
|
}
|
|
return input || '';
|
|
}
|
|
};
|
|
|
|
/**
|
|
* @const {number}
|
|
* @private
|
|
*/
|
|
shaka.text.VttTextParser.MPEG_TIMESCALE_ = 90000;
|
|
|
|
/**
|
|
* At this value, timestamps roll over in TS content.
|
|
* @const {number}
|
|
* @private
|
|
*/
|
|
shaka.text.VttTextParser.TS_ROLLOVER_ = 0x200000000;
|
|
|
|
/**
|
|
* @const
|
|
* @private {!RegExp}
|
|
* @example 00:00.000 or 00:00:00.000 or 0:00:00.000 or
|
|
* 00:00.00 or 00:00:00.00 or 0:00:00.00
|
|
*/
|
|
shaka.text.VttTextParser.timeFormat_ =
|
|
/(?:(\d{1,}):)?(\d{2}):(\d{2})\.(\d{2,3})/g;
|
|
|
|
shaka.text.TextEngine.registerParser(
|
|
'text/vtt', () => new shaka.text.VttTextParser());
|
|
|
|
shaka.text.TextEngine.registerParser(
|
|
'text/vtt; codecs="vtt"', () => new shaka.text.VttTextParser());
|
|
|
|
shaka.text.TextEngine.registerParser(
|
|
'text/vtt; codecs="wvtt"', () => new shaka.text.VttTextParser());
|