Source: lib/text/ttml_text_parser.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.text.TtmlTextParser');
  9. goog.require('goog.asserts');
  10. goog.require('goog.Uri');
  11. goog.require('shaka.log');
  12. goog.require('shaka.text.Cue');
  13. goog.require('shaka.text.CueRegion');
  14. goog.require('shaka.text.TextEngine');
  15. goog.require('shaka.util.ArrayUtils');
  16. goog.require('shaka.util.Error');
  17. goog.require('shaka.util.StringUtils');
  18. goog.require('shaka.util.TXml');
  21. /**
  22.  * @implements {shaka.extern.TextParser}
  23.  * @export
  24.  */
  25. shaka.text.TtmlTextParser = class {
  26.   /**
  27.    * @override
  28.    * @export
  29.    */
  30.   parseInit(data) {
  31.     goog.asserts.assert(false, 'TTML does not have init segments');
  32.   }
  34.   /**
  35.    * @override
  36.    * @export
  37.    */
  38.   setSequenceMode(sequenceMode) {
  39.     // Unused.
  40.   }
  42.   /**
  43.    * @override
  44.    * @export
  45.    */
  46.   setManifestType(manifestType) {
  47.     // Unused.
  48.   }
  50.   /**
  51.    * @override
  52.    * @export
  53.    */
  54.   parseMedia(data, time, uri) {
  55.     const TtmlTextParser = shaka.text.TtmlTextParser;
  56.     const TXml = shaka.util.TXml;
  57.     const ttpNs = TtmlTextParser.parameterNs_;
  58.     const ttsNs = TtmlTextParser.styleNs_;
  59.     const str = shaka.util.StringUtils.fromUTF8(data);
  60.     const cues = [];
  62.     // dont try to parse empty string as
  63.     // DOMParser will not throw error but return an errored xml
  64.     if (str == '') {
  65.       return cues;
  66.     }
  68.     const tt = TXml.parseXmlString(str, 'tt', /* includeParent= */ true);
  69.     if (!tt) {
  70.       throw new shaka.util.Error(
  71.           shaka.util.Error.Severity.CRITICAL,
  72.           shaka.util.Error.Category.TEXT,
  73.           shaka.util.Error.Code.INVALID_XML,
  74.           'Failed to parse TTML.');
  75.     }
  77.     const body = TXml.getElementsByTagName(tt, 'body')[0];
  78.     if (!body) {
  79.       return [];
  80.     }
  82.     // Get the framerate, subFrameRate and frameRateMultiplier if applicable.
  83.     const frameRate = TXml.getAttributeNSList(tt, ttpNs, 'frameRate');
  84.     const subFrameRate = TXml.getAttributeNSList(
  85.         tt, ttpNs, 'subFrameRate');
  86.     const frameRateMultiplier =
  87.         TXml.getAttributeNSList(tt, ttpNs, 'frameRateMultiplier');
  88.     const tickRate = TXml.getAttributeNSList(tt, ttpNs, 'tickRate');
  90.     const cellResolution = TXml.getAttributeNSList(
  91.         tt, ttpNs, 'cellResolution');
  92.     const spaceStyle = tt.attributes['xml:space'] || 'default';
  93.     const extent = TXml.getAttributeNSList(tt, ttsNs, 'extent');
  95.     if (spaceStyle != 'default' && spaceStyle != 'preserve') {
  96.       throw new shaka.util.Error(
  97.           shaka.util.Error.Severity.CRITICAL,
  98.           shaka.util.Error.Category.TEXT,
  99.           shaka.util.Error.Code.INVALID_XML,
  100.           'Invalid xml:space value: ' + spaceStyle);
  101.     }
  102.     const collapseMultipleSpaces = spaceStyle == 'default';
  104.     const rateInfo = new TtmlTextParser.RateInfo_(
  105.         frameRate, subFrameRate, frameRateMultiplier, tickRate);
  107.     const cellResolutionInfo =
  108.       TtmlTextParser.getCellResolution_(cellResolution);
  110.     const metadata = TXml.getElementsByTagName(tt, 'metadata')[0];
  111.     const metadataElements =
  112.         (metadata ? metadata.children : []).filter((c) => c != '\n');
  113.     const styles = TXml.getElementsByTagName(tt, 'style');
  114.     const regionElements = TXml.getElementsByTagName(tt, 'region');
  116.     const cueRegions = [];
  117.     for (const region of regionElements) {
  118.       const cueRegion =
  119.           TtmlTextParser.parseCueRegion_(region, styles, extent);
  120.       if (cueRegion) {
  121.         cueRegions.push(cueRegion);
  122.       }
  123.     }
  125.     // A <body> element should only contain <div> elements, not <p> or <span>
  126.     // elements.  We used to allow this, but it is non-compliant, and the
  127.     // loose nature of our previous parser made it difficult to implement TTML
  128.     // nesting more fully.
  129.     if (TXml.findChildren(body, 'p').length) {
  130.       throw new shaka.util.Error(
  131.           shaka.util.Error.Severity.CRITICAL,
  132.           shaka.util.Error.Category.TEXT,
  133.           shaka.util.Error.Code.INVALID_TEXT_CUE,
  134.           '<p> can only be inside <div> in TTML');
  135.     }
  137.     for (const div of TXml.findChildren(body, 'div')) {
  138.       // A <div> element should only contain <p>, not <span>.
  139.       if (TXml.findChildren(div, 'span').length) {
  140.         throw new shaka.util.Error(
  141.             shaka.util.Error.Severity.CRITICAL,
  142.             shaka.util.Error.Category.TEXT,
  143.             shaka.util.Error.Code.INVALID_TEXT_CUE,
  144.             '<span> can only be inside <p> in TTML');
  145.       }
  146.     }
  148.     const cue = TtmlTextParser.parseCue_(
  149.         body, time, rateInfo, metadataElements, styles,
  150.         regionElements, cueRegions, collapseMultipleSpaces,
  151.         cellResolutionInfo, /* parentCueElement= */ null,
  152.         /* isContent= */ false, uri);
  153.     if (cue) {
  154.       // According to the TTML spec, backgrounds default to transparent.
  155.       // So default the background of the top-level element to transparent.
  156.       // Nested elements may override that background color already.
  157.       if (!cue.backgroundColor) {
  158.         cue.backgroundColor = 'transparent';
  159.       }
  160.       cues.push(cue);
  161.     }
  163.     return cues;
  164.   }
  166.   /**
  167.    * Parses a TTML node into a Cue.
  168.    *
  169.    * @param {!shaka.extern.xml.Node} cueNode
  170.    * @param {shaka.extern.TextParser.TimeContext} timeContext
  171.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  172.    * @param {!Array.<!shaka.extern.xml.Node>} metadataElements
  173.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  174.    * @param {!Array.<!shaka.extern.xml.Node>} regionElements
  175.    * @param {!Array.<!shaka.text.CueRegion>} cueRegions
  176.    * @param {boolean} collapseMultipleSpaces
  177.    * @param {?{columns: number, rows: number}} cellResolution
  178.    * @param {?shaka.extern.xml.Node} parentCueElement
  179.    * @param {boolean} isContent
  180.    * @param {?(string|undefined)} uri
  181.    * @return {shaka.text.Cue}
  182.    * @private
  183.    */
  184.   static parseCue_(
  185.       cueNode, timeContext, rateInfo, metadataElements, styles, regionElements,
  186.       cueRegions, collapseMultipleSpaces, cellResolution, parentCueElement,
  187.       isContent, uri) {
  188.     const TXml = shaka.util.TXml;
  189.     const StringUtils = shaka.util.StringUtils;
  190.     /** @type {shaka.extern.xml.Node} */
  191.     let cueElement;
  192.     /** @type {?shaka.extern.xml.Node} */
  193.     let parentElement = parentCueElement;
  195.     if (TXml.isText(cueNode)) {
  196.       if (!isContent) {
  197.         // Ignore text elements outside the content. For example, whitespace
  198.         // on the same lexical level as the <p> elements, in a document with
  199.         // xml:space="preserve", should not be renderer.
  200.         return null;
  201.       }
  202.       // This should generate an "anonymous span" according to the TTML spec.
  203.       // So pretend the element was a <span>.  parentElement was set above, so
  204.       // we should still be able to correctly traverse up for timing
  205.       // information later.
  206.       /** @type {shaka.extern.xml.Node} */
  207.       const span = {
  208.         tagName: 'span',
  209.         children: [TXml.getTextContents(cueNode)],
  210.         attributes: {},
  211.         parent: null,
  212.       };
  213.       cueElement = span;
  214.     } else {
  215.       cueElement = cueNode;
  216.     }
  217.     goog.asserts.assert(cueElement, 'cueElement should be non-null!');
  219.     let imageElement = null;
  220.     for (const nameSpace of shaka.text.TtmlTextParser.smpteNsList_) {
  221.       imageElement = shaka.text.TtmlTextParser.getElementsFromCollection_(
  222.           cueElement, 'backgroundImage', metadataElements, '#',
  223.           nameSpace)[0];
  224.       if (imageElement) {
  225.         break;
  226.       }
  227.     }
  229.     let imageUri = null;
  230.     const backgroundImage = TXml.getAttributeNSList(
  231.         cueElement,
  232.         shaka.text.TtmlTextParser.smpteNsList_,
  233.         'backgroundImage');
  234.     if (uri && backgroundImage && !backgroundImage.startsWith('#')) {
  235.       const baseUri = new goog.Uri(uri);
  236.       const relativeUri = new goog.Uri(backgroundImage);
  237.       const newUri = baseUri.resolve(relativeUri).toString();
  238.       if (newUri) {
  239.         imageUri = newUri;
  240.       }
  241.     }
  243.     if (cueNode.tagName == 'p' || imageElement || imageUri) {
  244.       isContent = true;
  245.     }
  247.     const parentIsContent = isContent;
  249.     const spaceStyle = cueElement.attributes['xml:space'] ||
  250.         (collapseMultipleSpaces ? 'default' : 'preserve');
  252.     const localCollapseMultipleSpaces = spaceStyle == 'default';
  254.     // Parse any nested cues first.
  255.     const isLeafNode = cueElement.children.every(TXml.isText);
  256.     const nestedCues = [];
  257.     if (!isLeafNode) {
  258.       // Otherwise, recurse into the children.  Text nodes will convert into
  259.       // anonymous spans, which will then be leaf nodes.
  260.       for (const childNode of cueElement.children) {
  261.         const nestedCue = shaka.text.TtmlTextParser.parseCue_(
  262.             childNode,
  263.             timeContext,
  264.             rateInfo,
  265.             metadataElements,
  266.             styles,
  267.             regionElements,
  268.             cueRegions,
  269.             localCollapseMultipleSpaces,
  270.             cellResolution,
  271.             cueElement,
  272.             isContent,
  273.             uri,
  274.         );
  276.         // This node may or may not generate a nested cue.
  277.         if (nestedCue) {
  278.           nestedCues.push(nestedCue);
  279.         }
  280.       }
  281.     }
  283.     const isNested = /** @type {boolean} */ (parentCueElement != null);
  285.     const textContent = TXml.getTextContents(cueElement);
  286.     // In this regex, "\S" means "non-whitespace character".
  287.     const hasTextContent = cueElement.children.length &&
  288.         textContent &&
  289.         /\S/.test(textContent);
  291.     const hasTimeAttributes =
  292.         cueElement.attributes['begin'] ||
  293.         cueElement.attributes['end'] ||
  294.         cueElement.attributes['dur'];
  296.     if (!hasTimeAttributes && !hasTextContent && cueElement.tagName != 'br' &&
  297.         nestedCues.length == 0) {
  298.       if (!isNested) {
  299.         // Disregards empty <p> elements without time attributes nor content.
  300.         // <p begin="..." smpte:backgroundImage="..." /> will go through,
  301.         // as some information could be held by its attributes.
  302.         // <p /> won't, as it would not be displayed.
  303.         return null;
  304.       } else if (localCollapseMultipleSpaces) {
  305.         // Disregards empty anonymous spans when (local) trim is true.
  306.         return null;
  307.       }
  308.     }
  310.     // Get local time attributes.
  311.     let {start, end} = shaka.text.TtmlTextParser.parseTime_(
  312.         cueElement, rateInfo);
  313.     // Resolve local time relative to parent elements.  Time elements can appear
  314.     // all the way up to 'body', but not 'tt'.
  315.     while (parentElement && TXml.isNode(parentElement) &&
  316.         parentElement.tagName != 'tt') {
  317.       ({start, end} = shaka.text.TtmlTextParser.resolveTime_(
  318.           parentElement, rateInfo, start, end));
  319.       parentElement =
  320.         /** @type {shaka.extern.xml.Node} */ (parentElement.parent);
  321.     }
  323.     if (start == null) {
  324.       start = 0;
  325.     }
  326.     start += timeContext.periodStart;
  328.     // If end is null, that means the duration is effectively infinite.
  329.     if (end == null) {
  330.       end = Infinity;
  331.     } else {
  332.       end += timeContext.periodStart;
  333.     }
  335.     // Clip times to segment boundaries.
  336.     // https://github.com/shaka-project/shaka-player/issues/4631
  337.     start = Math.max(start, timeContext.segmentStart);
  338.     end = Math.min(end, timeContext.segmentEnd);
  340.     if (!hasTimeAttributes && nestedCues.length > 0) {
  341.       // If no time is defined for this cue, base the timing information on
  342.       // the time of the nested cues. In the case of multiple nested cues with
  343.       // different start times, it is the text displayer's responsibility to
  344.       // make sure that only the appropriate nested cue is drawn at any given
  345.       // time.
  346.       start = Infinity;
  347.       end = 0;
  348.       for (const cue of nestedCues) {
  349.         start = Math.min(start, cue.startTime);
  350.         end = Math.max(end, cue.endTime);
  351.       }
  352.     }
  354.     if (cueElement.tagName == 'br') {
  355.       const cue = new shaka.text.Cue(start, end, '');
  356.       cue.lineBreak = true;
  357.       return cue;
  358.     }
  360.     let payload = '';
  361.     if (isLeafNode) {
  362.       // If the childNodes are all text, this is a leaf node.  Get the payload.
  363.       payload = StringUtils.htmlUnescape(
  364.           shaka.util.TXml.getTextContents(cueElement) || '');
  365.       if (localCollapseMultipleSpaces) {
  366.         // Collapse multiple spaces into one.
  367.         payload = payload.replace(/\s+/g, ' ');
  368.       }
  369.     }
  371.     const cue = new shaka.text.Cue(start, end, payload);
  372.     cue.nestedCues = nestedCues;
  374.     if (!isContent) {
  375.       // If this is not a <p> element or a <div> with images, and it has no
  376.       // parent that was a <p> element, then it's part of the outer containers
  377.       // (e.g. the <body> or a normal <div> element within it).
  378.       cue.isContainer = true;
  379.     }
  381.     if (cellResolution) {
  382.       cue.cellResolution = cellResolution;
  383.     }
  385.     // Get other properties if available.
  386.     const regionElement = shaka.text.TtmlTextParser.getElementsFromCollection_(
  387.         cueElement, 'region', regionElements, /* prefix= */ '')[0];
  388.     // Do not actually apply that region unless it is non-inherited, though.
  389.     // This makes it so that, if a parent element has a region, the children
  390.     // don't also all independently apply the positioning of that region.
  391.     if (cueElement.attributes['region']) {
  392.       if (regionElement && regionElement.attributes['xml:id']) {
  393.         const regionId = regionElement.attributes['xml:id'];
  394.         cue.region = cueRegions.filter((region) => region.id == regionId)[0];
  395.       }
  396.     }
  398.     let regionElementForStyle = regionElement;
  399.     if (parentCueElement && isNested && !cueElement.attributes['region'] &&
  400.       !cueElement.attributes['style']) {
  401.       regionElementForStyle =
  402.           shaka.text.TtmlTextParser.getElementsFromCollection_(
  403.               parentCueElement, 'region', regionElements, /* prefix= */ '')[0];
  404.     }
  406.     shaka.text.TtmlTextParser.addStyle_(
  407.         cue,
  408.         cueElement,
  409.         regionElementForStyle,
  410.         /** @type {!shaka.extern.xml.Node} */(imageElement),
  411.         imageUri,
  412.         styles,
  413.         /** isNested= */ parentIsContent, // "nested in a <div>" doesn't count.
  414.         /** isLeaf= */ (nestedCues.length == 0));
  416.     return cue;
  417.   }
  419.   /**
  420.    * Parses an Element into a TextTrackCue or VTTCue.
  421.    *
  422.    * @param {!shaka.extern.xml.Node} regionElement
  423.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  424.    * Defined in the top of tt element and used principally for images.
  425.    * @param {?string} globalExtent
  426.    * @return {shaka.text.CueRegion}
  427.    * @private
  428.    */
  429.   static parseCueRegion_(regionElement, styles, globalExtent) {
  430.     const TtmlTextParser = shaka.text.TtmlTextParser;
  431.     const region = new shaka.text.CueRegion();
  432.     const id = regionElement.attributes['xml:id'];
  433.     if (!id) {
  434.       shaka.log.warning('TtmlTextParser parser encountered a region with ' +
  435.                         'no id. Region will be ignored.');
  436.       return null;
  437.     }
  438.     region.id = id;
  440.     let globalResults = null;
  441.     if (globalExtent) {
  442.       globalResults = TtmlTextParser.percentValues_.exec(globalExtent) ||
  443.         TtmlTextParser.pixelValues_.exec(globalExtent);
  444.     }
  445.     const globalWidth = globalResults ? Number(globalResults[1]) : null;
  446.     const globalHeight = globalResults ? Number(globalResults[2]) : null;
  448.     let results = null;
  449.     let percentage = null;
  450.     const extent = TtmlTextParser.getStyleAttributeFromRegion_(
  451.         regionElement, styles, 'extent');
  452.     if (extent) {
  453.       percentage = TtmlTextParser.percentValues_.exec(extent);
  454.       results = percentage || TtmlTextParser.pixelValues_.exec(extent);
  455.       if (results != null) {
  456.         region.width = Number(results[1]);
  457.         region.height = Number(results[2]);
  459.         if (!percentage) {
  460.           if (globalWidth != null) {
  461.             region.width = region.width * 100 / globalWidth;
  462.           }
  463.           if (globalHeight != null) {
  464.             region.height = region.height * 100 / globalHeight;
  465.           }
  466.         }
  468.         region.widthUnits = percentage || globalWidth != null ?
  469.                            shaka.text.CueRegion.units.PERCENTAGE :
  470.                            shaka.text.CueRegion.units.PX;
  472.         region.heightUnits = percentage || globalHeight != null ?
  473.                            shaka.text.CueRegion.units.PERCENTAGE :
  474.                            shaka.text.CueRegion.units.PX;
  475.       }
  476.     }
  478.     const origin = TtmlTextParser.getStyleAttributeFromRegion_(
  479.         regionElement, styles, 'origin');
  480.     if (origin) {
  481.       percentage = TtmlTextParser.percentValues_.exec(origin);
  482.       results = percentage || TtmlTextParser.pixelValues_.exec(origin);
  483.       if (results != null) {
  484.         region.viewportAnchorX = Number(results[1]);
  485.         region.viewportAnchorY = Number(results[2]);
  487.         if (!percentage) {
  488.           if (globalHeight != null) {
  489.             region.viewportAnchorY = region.viewportAnchorY * 100 /
  490.               globalHeight;
  491.           }
  492.           if (globalWidth != null) {
  493.             region.viewportAnchorX = region.viewportAnchorX * 100 /
  494.               globalWidth;
  495.           }
  496.         } else if (!extent) {
  497.           region.width = 100 - region.viewportAnchorX;
  498.           region.widthUnits = shaka.text.CueRegion.units.PERCENTAGE;
  499.           region.height = 100 - region.viewportAnchorY;
  500.           region.heightUnits = shaka.text.CueRegion.units.PERCENTAGE;
  501.         }
  503.         region.viewportAnchorUnits = percentage || globalWidth != null ?
  504.                   shaka.text.CueRegion.units.PERCENTAGE :
  505.                   shaka.text.CueRegion.units.PX;
  506.       }
  507.     }
  509.     return region;
  510.   }
  512.   /**
  513.    * Ensures any TTML RGBA's alpha range of 0-255 is converted to 0-1.
  514.    * @param {string} color
  515.    * @return {string}
  516.    * @private
  517.    */
  518.   static convertTTMLrgbaToHTMLrgba_(color) {
  519.     const rgba = color.match(/rgba\(([^)]+)\)/);
  520.     if (rgba) {
  521.       const values = rgba[1].split(',');
  522.       if (values.length == 4) {
  523.         values[3] = String(Number(values[3]) / 255);
  524.         return 'rgba(' + values.join(',') + ')';
  525.       }
  526.     }
  527.     return color;
  528.   }
  530.   /**
  531.    * Adds applicable style properties to a cue.
  532.    *
  533.    * @param {!shaka.text.Cue} cue
  534.    * @param {!shaka.extern.xml.Node} cueElement
  535.    * @param {shaka.extern.xml.Node} region
  536.    * @param {shaka.extern.xml.Node} imageElement
  537.    * @param {?string} imageUri
  538.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  539.    * @param {boolean} isNested
  540.    * @param {boolean} isLeaf
  541.    * @private
  542.    */
  543.   static addStyle_(
  544.       cue, cueElement, region, imageElement, imageUri, styles,
  545.       isNested, isLeaf) {
  546.     const TtmlTextParser = shaka.text.TtmlTextParser;
  547.     const TXml = shaka.util.TXml;
  548.     const Cue = shaka.text.Cue;
  550.     // Styles should be inherited from regions, if a style property is not
  551.     // associated with a Content element (or an anonymous span).
  552.     const shouldInheritRegionStyles = isNested || isLeaf;
  554.     const direction = TtmlTextParser.getStyleAttribute_(
  555.         cueElement, region, styles, 'direction', shouldInheritRegionStyles);
  556.     if (direction == 'rtl') {
  557.       cue.direction = Cue.direction.HORIZONTAL_RIGHT_TO_LEFT;
  558.     }
  560.     // Direction attribute specifies one-dimentional writing direction
  561.     // (left to right or right to left). Writing mode specifies that
  562.     // plus whether text is vertical or horizontal.
  563.     // They should not contradict each other. If they do, we give
  564.     // preference to writing mode.
  565.     const writingMode = TtmlTextParser.getStyleAttribute_(
  566.         cueElement, region, styles, 'writingMode', shouldInheritRegionStyles);
  567.     // Set cue's direction if the text is horizontal, and cue's writingMode if
  568.     // it's vertical.
  569.     if (writingMode == 'tb' || writingMode == 'tblr') {
  570.       cue.writingMode = Cue.writingMode.VERTICAL_LEFT_TO_RIGHT;
  571.     } else if (writingMode == 'tbrl') {
  572.       cue.writingMode = Cue.writingMode.VERTICAL_RIGHT_TO_LEFT;
  573.     } else if (writingMode == 'rltb' || writingMode == 'rl') {
  574.       cue.direction = Cue.direction.HORIZONTAL_RIGHT_TO_LEFT;
  575.     } else if (writingMode) {
  576.       cue.direction = Cue.direction.HORIZONTAL_LEFT_TO_RIGHT;
  577.     }
  579.     const align = TtmlTextParser.getStyleAttribute_(
  580.         cueElement, region, styles, 'textAlign', true);
  581.     if (align) {
  582.       cue.positionAlign = TtmlTextParser.textAlignToPositionAlign_[align];
  583.       cue.lineAlign = TtmlTextParser.textAlignToLineAlign_[align];
  585.       goog.asserts.assert(align.toUpperCase() in Cue.textAlign,
  586.           align.toUpperCase() + ' Should be in Cue.textAlign values!');
  588.       cue.textAlign = Cue.textAlign[align.toUpperCase()];
  589.     } else {
  590.       // Default value is START in the TTML spec: https://bit.ly/32OGmvo
  591.       // But to make the subtitle render consitent with other players and the
  592.       // shaka.text.Cue we use CENTER
  593.       cue.textAlign = Cue.textAlign.CENTER;
  594.     }
  596.     const displayAlign = TtmlTextParser.getStyleAttribute_(
  597.         cueElement, region, styles, 'displayAlign', true);
  598.     if (displayAlign) {
  599.       goog.asserts.assert(displayAlign.toUpperCase() in Cue.displayAlign,
  600.           displayAlign.toUpperCase() +
  601.                           ' Should be in Cue.displayAlign values!');
  602.       cue.displayAlign = Cue.displayAlign[displayAlign.toUpperCase()];
  603.     }
  605.     const color = TtmlTextParser.getStyleAttribute_(
  606.         cueElement, region, styles, 'color', shouldInheritRegionStyles);
  607.     if (color) {
  608.       cue.color = TtmlTextParser.convertTTMLrgbaToHTMLrgba_(color);
  609.     }
  611.     // Background color should not be set on a container.  If this is a nested
  612.     // cue, you can set the background.  If it's a top-level that happens to
  613.     // also be a leaf, you can set the background.
  614.     // See https://github.com/shaka-project/shaka-player/issues/2623
  615.     // This used to be handled in the displayer, but that is confusing.  The Cue
  616.     // structure should reflect what you want to happen in the displayer, and
  617.     // the displayer shouldn't have to know about TTML.
  618.     const backgroundColor = TtmlTextParser.getStyleAttribute_(
  619.         cueElement, region, styles, 'backgroundColor',
  620.         shouldInheritRegionStyles);
  621.     if (backgroundColor) {
  622.       cue.backgroundColor =
  623.         TtmlTextParser.convertTTMLrgbaToHTMLrgba_(backgroundColor);
  624.     }
  626.     const border = TtmlTextParser.getStyleAttribute_(
  627.         cueElement, region, styles, 'border', shouldInheritRegionStyles);
  628.     if (border) {
  629.       cue.border = border;
  630.     }
  632.     const fontFamily = TtmlTextParser.getStyleAttribute_(
  633.         cueElement, region, styles, 'fontFamily', shouldInheritRegionStyles);
  634.     // See https://github.com/sandflow/imscJS/blob/1.1.3/src/main/js/html.js#L1384
  635.     if (fontFamily) {
  636.       switch (fontFamily) {
  637.         case 'monospaceSerif':
  638.           cue.fontFamily = 'Courier New,Liberation Mono,Courier,monospace';
  639.           break;
  640.         case 'proportionalSansSerif':
  641.           cue.fontFamily = 'Arial,Helvetica,Liberation Sans,sans-serif';
  642.           break;
  643.         case 'sansSerif':
  644.           cue.fontFamily = 'sans-serif';
  645.           break;
  646.         case 'monospaceSansSerif':
  647.           cue.fontFamily = 'Consolas,monospace';
  648.           break;
  649.         case 'proportionalSerif':
  650.           cue.fontFamily = 'serif';
  651.           break;
  652.         default:
  653.           cue.fontFamily = fontFamily.split(',').filter((font) => {
  654.             return font != 'default';
  655.           }).join(',');
  656.           break;
  657.       }
  658.     }
  660.     const fontWeight = TtmlTextParser.getStyleAttribute_(
  661.         cueElement, region, styles, 'fontWeight', shouldInheritRegionStyles);
  662.     if (fontWeight && fontWeight == 'bold') {
  663.       cue.fontWeight = Cue.fontWeight.BOLD;
  664.     }
  666.     const wrapOption = TtmlTextParser.getStyleAttribute_(
  667.         cueElement, region, styles, 'wrapOption', shouldInheritRegionStyles);
  668.     if (wrapOption && wrapOption == 'noWrap') {
  669.       cue.wrapLine = false;
  670.     } else {
  671.       cue.wrapLine = true;
  672.     }
  674.     const lineHeight = TtmlTextParser.getStyleAttribute_(
  675.         cueElement, region, styles, 'lineHeight', shouldInheritRegionStyles);
  676.     if (lineHeight && lineHeight.match(TtmlTextParser.unitValues_)) {
  677.       cue.lineHeight = lineHeight;
  678.     }
  680.     const fontSize = TtmlTextParser.getStyleAttribute_(
  681.         cueElement, region, styles, 'fontSize', shouldInheritRegionStyles);
  682.     if (fontSize) {
  683.       const isValidFontSizeUnit =
  684.           fontSize.match(TtmlTextParser.unitValues_) ||
  685.           fontSize.match(TtmlTextParser.percentValue_);
  687.       if (isValidFontSizeUnit) {
  688.         cue.fontSize = fontSize;
  689.       }
  690.     }
  692.     const fontStyle = TtmlTextParser.getStyleAttribute_(
  693.         cueElement, region, styles, 'fontStyle', shouldInheritRegionStyles);
  694.     if (fontStyle) {
  695.       goog.asserts.assert(fontStyle.toUpperCase() in Cue.fontStyle,
  696.           fontStyle.toUpperCase() +
  697.                           ' Should be in Cue.fontStyle values!');
  698.       cue.fontStyle = Cue.fontStyle[fontStyle.toUpperCase()];
  699.     }
  701.     if (imageElement) {
  702.       // According to the spec, we should use imageType (camelCase), but
  703.       // historically we have checked for imagetype (lowercase).
  704.       // This was the case since background image support was first introduced
  705.       // in PR #1859, in April 2019, and first released in v2.5.0.
  706.       // Now we check for both, although only imageType (camelCase) is to spec.
  707.       const backgroundImageType =
  708.           imageElement.attributes['imageType'] ||
  709.           imageElement.attributes['imagetype'];
  710.       const backgroundImageEncoding = imageElement.attributes['encoding'];
  711.       const backgroundImageData = (TXml.getTextContents(imageElement)).trim();
  712.       if (backgroundImageType == 'PNG' &&
  713.           backgroundImageEncoding == 'Base64' &&
  714.           backgroundImageData) {
  715.         cue.backgroundImage = 'data:image/png;base64,' + backgroundImageData;
  716.       }
  717.     } else if (imageUri) {
  718.       cue.backgroundImage = imageUri;
  719.     }
  721.     const textOutline = TtmlTextParser.getStyleAttribute_(
  722.         cueElement, region, styles, 'textOutline', shouldInheritRegionStyles);
  723.     if (textOutline) {
  724.       // tts:textOutline isn't natively supported by browsers, but it can be
  725.       // mostly replicated using the non-standard -webkit-text-stroke-width and
  726.       // -webkit-text-stroke-color properties.
  727.       const split = textOutline.split(' ');
  728.       if (split[0].match(TtmlTextParser.unitValues_)) {
  729.         // There is no defined color, so default to the text color.
  730.         cue.textStrokeColor = cue.color;
  731.       } else {
  732.         cue.textStrokeColor =
  733.             TtmlTextParser.convertTTMLrgbaToHTMLrgba_(split[0]);
  734.         split.shift();
  735.       }
  736.       if (split[0] && split[0].match(TtmlTextParser.unitValues_)) {
  737.         cue.textStrokeWidth = split[0];
  738.       } else {
  739.         // If there is no width, or the width is not a number, don't draw a
  740.         // border.
  741.         cue.textStrokeColor = '';
  742.       }
  743.       // There is an optional blur radius also, but we have no way of
  744.       // replicating that, so ignore it.
  745.     }
  747.     const letterSpacing = TtmlTextParser.getStyleAttribute_(
  748.         cueElement, region, styles, 'letterSpacing', shouldInheritRegionStyles);
  749.     if (letterSpacing && letterSpacing.match(TtmlTextParser.unitValues_)) {
  750.       cue.letterSpacing = letterSpacing;
  751.     }
  753.     const linePadding = TtmlTextParser.getStyleAttribute_(
  754.         cueElement, region, styles, 'linePadding', shouldInheritRegionStyles);
  755.     if (linePadding && linePadding.match(TtmlTextParser.unitValues_)) {
  756.       cue.linePadding = linePadding;
  757.     }
  759.     const opacity = TtmlTextParser.getStyleAttribute_(
  760.         cueElement, region, styles, 'opacity', shouldInheritRegionStyles);
  761.     if (opacity) {
  762.       cue.opacity = parseFloat(opacity);
  763.     }
  765.     // Text decoration is an array of values which can come both from the
  766.     // element's style or be inherited from elements' parent nodes. All of those
  767.     // values should be applied as long as they don't contradict each other. If
  768.     // they do, elements' own style gets preference.
  769.     const textDecorationRegion = TtmlTextParser.getStyleAttributeFromRegion_(
  770.         region, styles, 'textDecoration');
  771.     if (textDecorationRegion) {
  772.       TtmlTextParser.addTextDecoration_(cue, textDecorationRegion);
  773.     }
  775.     const textDecorationElement = TtmlTextParser.getStyleAttributeFromElement_(
  776.         cueElement, styles, 'textDecoration');
  777.     if (textDecorationElement) {
  778.       TtmlTextParser.addTextDecoration_(cue, textDecorationElement);
  779.     }
  781.     const textCombine = TtmlTextParser.getStyleAttribute_(
  782.         cueElement, region, styles, 'textCombine', shouldInheritRegionStyles);
  783.     if (textCombine) {
  784.       cue.textCombineUpright = textCombine;
  785.     }
  787.     const ruby = TtmlTextParser.getStyleAttribute_(
  788.         cueElement, region, styles, 'ruby', shouldInheritRegionStyles);
  789.     switch (ruby) {
  790.       case 'container':
  791.         cue.rubyTag = 'ruby';
  792.         break;
  793.       case 'text':
  794.         cue.rubyTag = 'rt';
  795.         break;
  796.     }
  797.   }
  799.   /**
  800.    * Parses text decoration values and adds/removes them to/from the cue.
  801.    *
  802.    * @param {!shaka.text.Cue} cue
  803.    * @param {string} decoration
  804.    * @private
  805.    */
  806.   static addTextDecoration_(cue, decoration) {
  807.     const Cue = shaka.text.Cue;
  808.     for (const value of decoration.split(' ')) {
  809.       switch (value) {
  810.         case 'underline':
  811.           if (!cue.textDecoration.includes(Cue.textDecoration.UNDERLINE)) {
  812.             cue.textDecoration.push(Cue.textDecoration.UNDERLINE);
  813.           }
  814.           break;
  815.         case 'noUnderline':
  816.           if (cue.textDecoration.includes(Cue.textDecoration.UNDERLINE)) {
  817.             shaka.util.ArrayUtils.remove(cue.textDecoration,
  818.                 Cue.textDecoration.UNDERLINE);
  819.           }
  820.           break;
  821.         case 'lineThrough':
  822.           if (!cue.textDecoration.includes(Cue.textDecoration.LINE_THROUGH)) {
  823.             cue.textDecoration.push(Cue.textDecoration.LINE_THROUGH);
  824.           }
  825.           break;
  826.         case 'noLineThrough':
  827.           if (cue.textDecoration.includes(Cue.textDecoration.LINE_THROUGH)) {
  828.             shaka.util.ArrayUtils.remove(cue.textDecoration,
  829.                 Cue.textDecoration.LINE_THROUGH);
  830.           }
  831.           break;
  832.         case 'overline':
  833.           if (!cue.textDecoration.includes(Cue.textDecoration.OVERLINE)) {
  834.             cue.textDecoration.push(Cue.textDecoration.OVERLINE);
  835.           }
  836.           break;
  837.         case 'noOverline':
  838.           if (cue.textDecoration.includes(Cue.textDecoration.OVERLINE)) {
  839.             shaka.util.ArrayUtils.remove(cue.textDecoration,
  840.                 Cue.textDecoration.OVERLINE);
  841.           }
  842.           break;
  843.       }
  844.     }
  845.   }
  847.   /**
  848.    * Finds a specified attribute on either the original cue element or its
  849.    * associated region and returns the value if the attribute was found.
  850.    *
  851.    * @param {!shaka.extern.xml.Node} cueElement
  852.    * @param {shaka.extern.xml.Node} region
  853.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  854.    * @param {string} attribute
  855.    * @param {boolean=} shouldInheritRegionStyles
  856.    * @return {?string}
  857.    * @private
  858.    */
  859.   static getStyleAttribute_(cueElement, region, styles, attribute,
  860.       shouldInheritRegionStyles=true) {
  861.     // An attribute can be specified on region level or in a styling block
  862.     // associated with the region or original element.
  863.     const TtmlTextParser = shaka.text.TtmlTextParser;
  864.     const attr = TtmlTextParser.getStyleAttributeFromElement_(
  865.         cueElement, styles, attribute);
  866.     if (attr) {
  867.       return attr;
  868.     }
  870.     if (shouldInheritRegionStyles) {
  871.       return TtmlTextParser.getStyleAttributeFromRegion_(
  872.           region, styles, attribute);
  873.     }
  874.     return null;
  875.   }
  877.   /**
  878.    * Finds a specified attribute on the element's associated region
  879.    * and returns the value if the attribute was found.
  880.    *
  881.    * @param {shaka.extern.xml.Node} region
  882.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  883.    * @param {string} attribute
  884.    * @return {?string}
  885.    * @private
  886.    */
  887.   static getStyleAttributeFromRegion_(region, styles, attribute) {
  888.     const TXml = shaka.util.TXml;
  889.     const ttsNs = shaka.text.TtmlTextParser.styleNs_;
  891.     if (!region) {
  892.       return null;
  893.     }
  895.     const attr = TXml.getAttributeNSList(region, ttsNs, attribute);
  896.     if (attr) {
  897.       return attr;
  898.     }
  900.     return shaka.text.TtmlTextParser.getInheritedStyleAttribute_(
  901.         region, styles, attribute);
  902.   }
  904.   /**
  905.    * Finds a specified attribute on the cue element and returns the value
  906.    * if the attribute was found.
  907.    *
  908.    * @param {!shaka.extern.xml.Node} cueElement
  909.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  910.    * @param {string} attribute
  911.    * @return {?string}
  912.    * @private
  913.    */
  914.   static getStyleAttributeFromElement_(cueElement, styles, attribute) {
  915.     const TXml = shaka.util.TXml;
  916.     const ttsNs = shaka.text.TtmlTextParser.styleNs_;
  918.     // Styling on elements should take precedence
  919.     // over the main styling attributes
  920.     const elementAttribute = TXml.getAttributeNSList(
  921.         cueElement,
  922.         ttsNs,
  923.         attribute);
  925.     if (elementAttribute) {
  926.       return elementAttribute;
  927.     }
  928.     return shaka.text.TtmlTextParser.getInheritedStyleAttribute_(
  929.         cueElement, styles, attribute);
  930.   }
  932.   /**
  933.    * Finds a specified attribute on an element's styles and the styles those
  934.    * styles inherit from.
  935.    *
  936.    * @param {!shaka.extern.xml.Node} element
  937.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  938.    * @param {string} attribute
  939.    * @return {?string}
  940.    * @private
  941.    */
  942.   static getInheritedStyleAttribute_(element, styles, attribute) {
  943.     const TXml = shaka.util.TXml;
  944.     const ttsNs = shaka.text.TtmlTextParser.styleNs_;
  945.     const ebuttsNs = shaka.text.TtmlTextParser.styleEbuttsNs_;
  947.     const inheritedStyles =
  948.         shaka.text.TtmlTextParser.getElementsFromCollection_(
  949.             element, 'style', styles, /* prefix= */ '');
  951.     let styleValue = null;
  953.     // The last value in our styles stack takes the precedence over the others
  954.     for (let i = 0; i < inheritedStyles.length; i++) {
  955.       // Check ebu namespace first.
  956.       let styleAttributeValue = TXml.getAttributeNS(
  957.           inheritedStyles[i],
  958.           ebuttsNs,
  959.           attribute);
  961.       if (!styleAttributeValue) {
  962.         // Fall back to tts namespace.
  963.         styleAttributeValue = TXml.getAttributeNSList(
  964.             inheritedStyles[i],
  965.             ttsNs,
  966.             attribute);
  967.       }
  969.       if (!styleAttributeValue) {
  970.         // Next, check inheritance.
  971.         // Styles can inherit from other styles, so traverse up that chain.
  972.         styleAttributeValue =
  973.             shaka.text.TtmlTextParser.getStyleAttributeFromElement_(
  974.                 inheritedStyles[i], styles, attribute);
  975.       }
  977.       if (styleAttributeValue) {
  978.         styleValue = styleAttributeValue;
  979.       }
  980.     }
  982.     return styleValue;
  983.   }
  986.   /**
  987.    * Selects items from |collection| whose id matches |attributeName|
  988.    * from |element|.
  989.    *
  990.    * @param {shaka.extern.xml.Node} element
  991.    * @param {string} attributeName
  992.    * @param {!Array.<shaka.extern.xml.Node>} collection
  993.    * @param {string} prefixName
  994.    * @param {string=} nsName
  995.    * @return {!Array.<!shaka.extern.xml.Node>}
  996.    * @private
  997.    */
  998.   static getElementsFromCollection_(
  999.       element, attributeName, collection, prefixName, nsName) {
  1000.     const items = [];
  1002.     if (!element || collection.length < 1) {
  1003.       return items;
  1004.     }
  1006.     const attributeValue = shaka.text.TtmlTextParser.getInheritedAttribute_(
  1007.         element, attributeName, nsName);
  1009.     if (attributeValue) {
  1010.       // There could be multiple items in one attribute
  1011.       // <span style="style1 style2">A cue</span>
  1012.       const itemNames = attributeValue.split(' ');
  1014.       for (const name of itemNames) {
  1015.         for (const item of collection) {
  1016.           if ((prefixName + item.attributes['xml:id']) == name) {
  1017.             items.push(item);
  1018.             break;
  1019.           }
  1020.         }
  1021.       }
  1022.     }
  1024.     return items;
  1025.   }
  1028.   /**
  1029.    * Traverses upwards from a given node until a given attribute is found.
  1030.    *
  1031.    * @param {!shaka.extern.xml.Node} element
  1032.    * @param {string} attributeName
  1033.    * @param {string=} nsName
  1034.    * @return {?string}
  1035.    * @private
  1036.    */
  1037.   static getInheritedAttribute_(element, attributeName, nsName) {
  1038.     let ret = null;
  1039.     const TXml = shaka.util.TXml;
  1040.     while (!ret) {
  1041.       ret = nsName ?
  1042.           TXml.getAttributeNS(element, nsName, attributeName) :
  1043.           element.attributes[attributeName];
  1044.       if (ret) {
  1045.         break;
  1046.       }
  1048.       // Element.parentNode can lead to XMLDocument, which is not an Element and
  1049.       // has no getAttribute().
  1050.       const parentNode = element.parent;
  1051.       if (parentNode) {
  1052.         element = parentNode;
  1053.       } else {
  1054.         break;
  1055.       }
  1056.     }
  1057.     return ret;
  1058.   }
  1060.   /**
  1061.    * Factor parent/ancestor time attributes into the parsed time of a
  1062.    * child/descendent.
  1063.    *
  1064.    * @param {!shaka.extern.xml.Node} parentElement
  1065.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1066.    * @param {?number} start The child's start time
  1067.    * @param {?number} end The child's end time
  1068.    * @return {{start: ?number, end: ?number}}
  1069.    * @private
  1070.    */
  1071.   static resolveTime_(parentElement, rateInfo, start, end) {
  1072.     const parentTime = shaka.text.TtmlTextParser.parseTime_(
  1073.         parentElement, rateInfo);
  1075.     if (start == null) {
  1076.       // No start time of your own?  Inherit from the parent.
  1077.       start = parentTime.start;
  1078.     } else {
  1079.       // Otherwise, the start time is relative to the parent's start time.
  1080.       if (parentTime.start != null) {
  1081.         start += parentTime.start;
  1082.       }
  1083.     }
  1085.     if (end == null) {
  1086.       // No end time of your own?  Inherit from the parent.
  1087.       end = parentTime.end;
  1088.     } else {
  1089.       // Otherwise, the end time is relative to the parent's _start_ time.
  1090.       // This is not a typo.  Both times are relative to the parent's _start_.
  1091.       if (parentTime.start != null) {
  1092.         end += parentTime.start;
  1093.       }
  1094.     }
  1096.     return {start, end};
  1097.   }
  1099.   /**
  1100.    * Parse TTML time attributes from the given element.
  1101.    *
  1102.    * @param {!shaka.extern.xml.Node} element
  1103.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1104.    * @return {{start: ?number, end: ?number}}
  1105.    * @private
  1106.    */
  1107.   static parseTime_(element, rateInfo) {
  1108.     const start = shaka.text.TtmlTextParser.parseTimeAttribute_(
  1109.         element.attributes['begin'], rateInfo);
  1110.     let end = shaka.text.TtmlTextParser.parseTimeAttribute_(
  1111.         element.attributes['end'], rateInfo);
  1112.     const duration = shaka.text.TtmlTextParser.parseTimeAttribute_(
  1113.         element.attributes['dur'], rateInfo);
  1114.     if (end == null && duration != null) {
  1115.       end = start + duration;
  1116.     }
  1117.     return {start, end};
  1118.   }
  1120.   /**
  1121.    * Parses a TTML time from the given attribute text.
  1122.    *
  1123.    * @param {string} text
  1124.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1125.    * @return {?number}
  1126.    * @private
  1127.    */
  1128.   static parseTimeAttribute_(text, rateInfo) {
  1129.     let ret = null;
  1130.     const TtmlTextParser = shaka.text.TtmlTextParser;
  1132.     if (TtmlTextParser.timeColonFormatFrames_.test(text)) {
  1133.       ret = TtmlTextParser.parseColonTimeWithFrames_(rateInfo, text);
  1134.     } else if (TtmlTextParser.timeColonFormat_.test(text)) {
  1135.       ret = TtmlTextParser.parseTimeFromRegex_(
  1136.           TtmlTextParser.timeColonFormat_, text);
  1137.     } else if (TtmlTextParser.timeColonFormatMilliseconds_.test(text)) {
  1138.       ret = TtmlTextParser.parseTimeFromRegex_(
  1139.           TtmlTextParser.timeColonFormatMilliseconds_, text);
  1140.     } else if (TtmlTextParser.timeFramesFormat_.test(text)) {
  1141.       ret = TtmlTextParser.parseFramesTime_(rateInfo, text);
  1142.     } else if (TtmlTextParser.timeTickFormat_.test(text)) {
  1143.       ret = TtmlTextParser.parseTickTime_(rateInfo, text);
  1144.     } else if (TtmlTextParser.timeHMSFormat_.test(text)) {
  1145.       ret = TtmlTextParser.parseTimeFromRegex_(
  1146.           TtmlTextParser.timeHMSFormat_, text);
  1147.     } else if (text) {
  1148.       // It's not empty or null, but it doesn't match a known format.
  1149.       throw new shaka.util.Error(
  1150.           shaka.util.Error.Severity.CRITICAL,
  1151.           shaka.util.Error.Category.TEXT,
  1152.           shaka.util.Error.Code.INVALID_TEXT_CUE,
  1153.           'Could not parse cue time range in TTML');
  1154.     }
  1156.     return ret;
  1157.   }
  1159.   /**
  1160.    * Parses a TTML time in frame format.
  1161.    *
  1162.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1163.    * @param {string} text
  1164.    * @return {?number}
  1165.    * @private
  1166.    */
  1167.   static parseFramesTime_(rateInfo, text) {
  1168.     // 75f or 75.5f
  1169.     const results = shaka.text.TtmlTextParser.timeFramesFormat_.exec(text);
  1170.     const frames = Number(results[1]);
  1172.     return frames / rateInfo.frameRate;
  1173.   }
  1175.   /**
  1176.    * Parses a TTML time in tick format.
  1177.    *
  1178.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1179.    * @param {string} text
  1180.    * @return {?number}
  1181.    * @private
  1182.    */
  1183.   static parseTickTime_(rateInfo, text) {
  1184.     // 50t or 50.5t
  1185.     const results = shaka.text.TtmlTextParser.timeTickFormat_.exec(text);
  1186.     const ticks = Number(results[1]);
  1188.     return ticks / rateInfo.tickRate;
  1189.   }
  1191.   /**
  1192.    * Parses a TTML colon formatted time containing frames.
  1193.    *
  1194.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1195.    * @param {string} text
  1196.    * @return {?number}
  1197.    * @private
  1198.    */
  1199.   static parseColonTimeWithFrames_(rateInfo, text) {
  1200.     // 01:02:43:07 ('07' is frames) or 01:02:43:07.1 (subframes)
  1201.     const results = shaka.text.TtmlTextParser.timeColonFormatFrames_.exec(text);
  1203.     const hours = Number(results[1]);
  1204.     const minutes = Number(results[2]);
  1205.     let seconds = Number(results[3]);
  1206.     let frames = Number(results[4]);
  1207.     const subframes = Number(results[5]) || 0;
  1209.     frames += subframes / rateInfo.subFrameRate;
  1210.     seconds += frames / rateInfo.frameRate;
  1212.     return seconds + (minutes * 60) + (hours * 3600);
  1213.   }
  1215.   /**
  1216.    * Parses a TTML time with a given regex. Expects regex to be some
  1217.    * sort of a time-matcher to match hours, minutes, seconds and milliseconds
  1218.    *
  1219.    * @param {!RegExp} regex
  1220.    * @param {string} text
  1221.    * @return {?number}
  1222.    * @private
  1223.    */
  1224.   static parseTimeFromRegex_(regex, text) {
  1225.     const results = regex.exec(text);
  1226.     if (results == null || results[0] == '') {
  1227.       return null;
  1228.     }
  1229.     // This capture is optional, but will still be in the array as undefined,
  1230.     // in which case it is 0.
  1231.     const hours = Number(results[1]) || 0;
  1232.     const minutes = Number(results[2]) || 0;
  1233.     const seconds = Number(results[3]) || 0;
  1234.     const milliseconds = Number(results[4]) || 0;
  1236.     return (milliseconds / 1000) + seconds + (minutes * 60) + (hours * 3600);
  1237.   }
  1239.   /**
  1240.    * If ttp:cellResolution provided returns cell resolution info
  1241.    * with number of columns and rows into which the Root Container
  1242.    * Region area is divided
  1243.    *
  1244.    * @param {?string} cellResolution
  1245.    * @return {?{columns: number, rows: number}}
  1246.    * @private
  1247.    */
  1248.   static getCellResolution_(cellResolution) {
  1249.     if (!cellResolution) {
  1250.       return null;
  1251.     }
  1252.     const matches = /^(\d+) (\d+)$/.exec(cellResolution);
  1254.     if (!matches) {
  1255.       return null;
  1256.     }
  1258.     const columns = parseInt(matches[1], 10);
  1259.     const rows = parseInt(matches[2], 10);
  1261.     return {columns, rows};
  1262.   }
  1263. };
  1265. /**
  1266.  * @summary
  1267.  * Contains information about frame/subframe rate
  1268.  * and frame rate multiplier for time in frame format.
  1269.  *
  1270.  * @example 01:02:03:04(4 frames) or 01:02:03:04.1(4 frames, 1 subframe)
  1271.  * @private
  1272.  */
  1273. shaka.text.TtmlTextParser.RateInfo_ = class {
  1274.   /**
  1275.    * @param {?string} frameRate
  1276.    * @param {?string} subFrameRate
  1277.    * @param {?string} frameRateMultiplier
  1278.    * @param {?string} tickRate
  1279.    */
  1280.   constructor(frameRate, subFrameRate, frameRateMultiplier, tickRate) {
  1281.     /**
  1282.      * @type {number}
  1283.      */
  1284.     this.frameRate = Number(frameRate) || 30;
  1286.     /**
  1287.      * @type {number}
  1288.      */
  1289.     this.subFrameRate = Number(subFrameRate) || 1;
  1291.     /**
  1292.      * @type {number}
  1293.      */
  1294.     this.tickRate = Number(tickRate);
  1295.     if (this.tickRate == 0) {
  1296.       if (frameRate) {
  1297.         this.tickRate = this.frameRate * this.subFrameRate;
  1298.       } else {
  1299.         this.tickRate = 1;
  1300.       }
  1301.     }
  1303.     if (frameRateMultiplier) {
  1304.       const multiplierResults = /^(\d+) (\d+)$/g.exec(frameRateMultiplier);
  1305.       if (multiplierResults) {
  1306.         const numerator = Number(multiplierResults[1]);
  1307.         const denominator = Number(multiplierResults[2]);
  1308.         const multiplierNum = numerator / denominator;
  1309.         this.frameRate *= multiplierNum;
  1310.       }
  1311.     }
  1312.   }
  1313. };
  1315. /**
  1316.  * @const
  1317.  * @private {!RegExp}
  1318.  * @example 50.17% 10%
  1319.  */
  1320. shaka.text.TtmlTextParser.percentValues_ =
  1321.     /^(\d{1,2}(?:\.\d+)?|100(?:\.0+)?)% (\d{1,2}(?:\.\d+)?|100(?:\.0+)?)%$/;
  1323. /**
  1324.  * @const
  1325.  * @private {!RegExp}
  1326.  * @example 0.6% 90% 300% 1000%
  1327.  */
  1328. shaka.text.TtmlTextParser.percentValue_ = /^(\d{1,4}(?:\.\d+)?|100)%$/;
  1330. /**
  1331.  * @const
  1332.  * @private {!RegExp}
  1333.  * @example 100px, 8em, 0.80c
  1334.  */
  1335. shaka.text.TtmlTextParser.unitValues_ = /^(\d+px|\d+em|\d*\.?\d+c)$/;
  1337. /**
  1338.  * @const
  1339.  * @private {!RegExp}
  1340.  * @example 100px
  1341.  */
  1342. shaka.text.TtmlTextParser.pixelValues_ = /^(\d+)px (\d+)px$/;
  1344. /**
  1345.  * @const
  1346.  * @private {!RegExp}
  1347.  * @example 00:00:40:07 (7 frames) or 00:00:40:07.1 (7 frames, 1 subframe)
  1348.  */
  1349. shaka.text.TtmlTextParser.timeColonFormatFrames_ =
  1350.     /^(\d{2,}):(\d{2}):(\d{2}):(\d{2})\.?(\d+)?$/;
  1352. /**
  1353.  * @const
  1354.  * @private {!RegExp}
  1355.  * @example 00:00:40 or 00:40
  1356.  */
  1357. shaka.text.TtmlTextParser.timeColonFormat_ = /^(?:(\d{2,}):)?(\d{2}):(\d{2})$/;
  1359. /**
  1360.  * @const
  1361.  * @private {!RegExp}
  1362.  * @example 01:02:43.0345555 or 02:43.03 or 02:45.5
  1363.  */
  1364. shaka.text.TtmlTextParser.timeColonFormatMilliseconds_ =
  1365.     /^(?:(\d{2,}):)?(\d{2}):(\d{2}\.\d+)$/;
  1367. /**
  1368.  * @const
  1369.  * @private {!RegExp}
  1370.  * @example 75f or 75.5f
  1371.  */
  1372. shaka.text.TtmlTextParser.timeFramesFormat_ = /^(\d*(?:\.\d*)?)f$/;
  1374. /**
  1375.  * @const
  1376.  * @private {!RegExp}
  1377.  * @example 50t or 50.5t
  1378.  */
  1379. shaka.text.TtmlTextParser.timeTickFormat_ = /^(\d*(?:\.\d*)?)t$/;
  1381. /**
  1382.  * @const
  1383.  * @private {!RegExp}
  1384.  * @example 3.45h, 3m or 4.20s
  1385.  */
  1386. shaka.text.TtmlTextParser.timeHMSFormat_ =
  1387.     new RegExp(['^(?:(\\d*(?:\\.\\d*)?)h)?',
  1388.       '(?:(\\d*(?:\\.\\d*)?)m)?',
  1389.       '(?:(\\d*(?:\\.\\d*)?)s)?',
  1390.       '(?:(\\d*(?:\\.\\d*)?)ms)?$'].join(''));
  1392. /**
  1393.  * @const
  1394.  * @private {!Object.<string, shaka.text.Cue.lineAlign>}
  1395.  */
  1396. shaka.text.TtmlTextParser.textAlignToLineAlign_ = {
  1397.   'left': shaka.text.Cue.lineAlign.START,
  1398.   'center': shaka.text.Cue.lineAlign.CENTER,
  1399.   'right': shaka.text.Cue.lineAlign.END,
  1400.   'start': shaka.text.Cue.lineAlign.START,
  1401.   'end': shaka.text.Cue.lineAlign.END,
  1402. };
  1404. /**
  1405.  * @const
  1406.  * @private {!Object.<string, shaka.text.Cue.positionAlign>}
  1407.  */
  1408. shaka.text.TtmlTextParser.textAlignToPositionAlign_ = {
  1409.   'left': shaka.text.Cue.positionAlign.LEFT,
  1410.   'center': shaka.text.Cue.positionAlign.CENTER,
  1411.   'right': shaka.text.Cue.positionAlign.RIGHT,
  1412. };
  1414. /**
  1415.  * The namespace URL for TTML parameters.  Can be assigned any name in the TTML
  1416.  * document, not just "ttp:", so we use this with getAttributeNS() to ensure
  1417.  * that we support arbitrary namespace names.
  1418.  *
  1419.  * @const {!Array.<string>}
  1420.  * @private
  1421.  */
  1422. shaka.text.TtmlTextParser.parameterNs_ = [
  1423.   'http://www.w3.org/ns/ttml#parameter',
  1424.   'http://www.w3.org/2006/10/ttaf1#parameter',
  1425. ];
  1427. /**
  1428.  * The namespace URL for TTML styles.  Can be assigned any name in the TTML
  1429.  * document, not just "tts:", so we use this with getAttributeNS() to ensure
  1430.  * that we support arbitrary namespace names.
  1431.  *
  1432.  * @const {!Array.<string>}
  1433.  * @private
  1434.  */
  1435. shaka.text.TtmlTextParser.styleNs_ = [
  1436.   'http://www.w3.org/ns/ttml#styling',
  1437.   'http://www.w3.org/2006/10/ttaf1#styling',
  1438. ];
  1440. /**
  1441.  * The namespace URL for EBU TTML styles.  Can be assigned any name in the TTML
  1442.  * document, not just "ebutts:", so we use this with getAttributeNS() to ensure
  1443.  * that we support arbitrary namespace names.
  1444.  *
  1445.  * @const {string}
  1446.  * @private
  1447.  */
  1448. shaka.text.TtmlTextParser.styleEbuttsNs_ = 'urn:ebu:tt:style';
  1450. /**
  1451.  * The supported namespace URLs for SMPTE fields.
  1452.  * @const {!Array.<string>}
  1453.  * @private
  1454.  */
  1455. shaka.text.TtmlTextParser.smpteNsList_ = [
  1456.   'http://www.smpte-ra.org/schemas/2052-1/2010/smpte-tt',
  1457.   'http://www.smpte-ra.org/schemas/2052-1/2013/smpte-tt',
  1458. ];
  1460. shaka.text.TextEngine.registerParser(
  1461.     'application/ttml+xml', () => new shaka.text.TtmlTextParser());