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');
  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 = metadata ? metadata.children : [];
  112.     const styles = TXml.getElementsByTagName(tt, 'style');
  113.     const regionElements = TXml.getElementsByTagName(tt, 'region');
  115.     const cueRegions = [];
  116.     for (const region of regionElements) {
  117.       const cueRegion =
  118.           TtmlTextParser.parseCueRegion_(region, styles, extent);
  119.       if (cueRegion) {
  120.         cueRegions.push(cueRegion);
  121.       }
  122.     }
  124.     // A <body> element should only contain <div> elements, not <p> or <span>
  125.     // elements.  We used to allow this, but it is non-compliant, and the
  126.     // loose nature of our previous parser made it difficult to implement TTML
  127.     // nesting more fully.
  128.     if (TXml.findChildren(body, 'p').length) {
  129.       throw new shaka.util.Error(
  130.           shaka.util.Error.Severity.CRITICAL,
  131.           shaka.util.Error.Category.TEXT,
  132.           shaka.util.Error.Code.INVALID_TEXT_CUE,
  133.           '<p> can only be inside <div> in TTML');
  134.     }
  136.     for (const div of TXml.findChildren(body, 'div')) {
  137.       // A <div> element should only contain <p>, not <span>.
  138.       if (TXml.findChildren(div, 'span').length) {
  139.         throw new shaka.util.Error(
  140.             shaka.util.Error.Severity.CRITICAL,
  141.             shaka.util.Error.Category.TEXT,
  142.             shaka.util.Error.Code.INVALID_TEXT_CUE,
  143.             '<span> can only be inside <p> in TTML');
  144.       }
  145.     }
  147.     const cue = TtmlTextParser.parseCue_(
  148.         body, time, rateInfo, metadataElements, styles,
  149.         regionElements, cueRegions, collapseMultipleSpaces,
  150.         cellResolutionInfo, /* parentCueElement= */ null,
  151.         /* isContent= */ false, uri);
  152.     if (cue) {
  153.       // According to the TTML spec, backgrounds default to transparent.
  154.       // So default the background of the top-level element to transparent.
  155.       // Nested elements may override that background color already.
  156.       if (!cue.backgroundColor) {
  157.         cue.backgroundColor = 'transparent';
  158.       }
  159.       cues.push(cue);
  160.     }
  162.     return cues;
  163.   }
  165.   /**
  166.    * Parses a TTML node into a Cue.
  167.    *
  168.    * @param {!shaka.extern.xml.Node} cueNode
  169.    * @param {shaka.extern.TextParser.TimeContext} timeContext
  170.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  171.    * @param {!Array.<!shaka.extern.xml.Node>} metadataElements
  172.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  173.    * @param {!Array.<!shaka.extern.xml.Node>} regionElements
  174.    * @param {!Array.<!shaka.text.CueRegion>} cueRegions
  175.    * @param {boolean} collapseMultipleSpaces
  176.    * @param {?{columns: number, rows: number}} cellResolution
  177.    * @param {?shaka.extern.xml.Node} parentCueElement
  178.    * @param {boolean} isContent
  179.    * @param {?(string|undefined)} uri
  180.    * @return {shaka.text.Cue}
  181.    * @private
  182.    */
  183.   static parseCue_(
  184.       cueNode, timeContext, rateInfo, metadataElements, styles, regionElements,
  185.       cueRegions, collapseMultipleSpaces, cellResolution, parentCueElement,
  186.       isContent, uri) {
  187.     const TXml = shaka.util.TXml;
  188.     const StringUtils = shaka.util.StringUtils;
  189.     /** @type {shaka.extern.xml.Node} */
  190.     let cueElement;
  191.     /** @type {?shaka.extern.xml.Node} */
  192.     let parentElement = parentCueElement;
  194.     if (TXml.isText(cueNode)) {
  195.       if (!isContent) {
  196.         // Ignore text elements outside the content. For example, whitespace
  197.         // on the same lexical level as the <p> elements, in a document with
  198.         // xml:space="preserve", should not be renderer.
  199.         return null;
  200.       }
  201.       // This should generate an "anonymous span" according to the TTML spec.
  202.       // So pretend the element was a <span>.  parentElement was set above, so
  203.       // we should still be able to correctly traverse up for timing
  204.       // information later.
  205.       /** @type {shaka.extern.xml.Node} */
  206.       const span = {
  207.         tagName: 'span',
  208.         children: [TXml.getTextContents(cueNode)],
  209.         attributes: {},
  210.         parent: null,
  211.       };
  212.       cueElement = span;
  213.     } else {
  214.       cueElement = cueNode;
  215.     }
  216.     goog.asserts.assert(cueElement, 'cueElement should be non-null!');
  218.     let imageElement = null;
  219.     for (const nameSpace of shaka.text.TtmlTextParser.smpteNsList_) {
  220.       imageElement = shaka.text.TtmlTextParser.getElementsFromCollection_(
  221.           cueElement, 'backgroundImage', metadataElements, '#',
  222.           nameSpace)[0];
  223.       if (imageElement) {
  224.         break;
  225.       }
  226.     }
  228.     let imageUri = null;
  229.     const backgroundImage = TXml.getAttributeNSList(
  230.         cueElement,
  231.         shaka.text.TtmlTextParser.smpteNsList_,
  232.         'backgroundImage');
  233.     if (uri && backgroundImage && !backgroundImage.startsWith('#')) {
  234.       const baseUri = new goog.Uri(uri);
  235.       const relativeUri = new goog.Uri(backgroundImage);
  236.       const newUri = baseUri.resolve(relativeUri).toString();
  237.       if (newUri) {
  238.         imageUri = newUri;
  239.       }
  240.     }
  242.     if (cueNode.tagName == 'p' || imageElement || imageUri) {
  243.       isContent = true;
  244.     }
  246.     const parentIsContent = isContent;
  248.     const spaceStyle = cueElement.attributes['xml:space'] ||
  249.         (collapseMultipleSpaces ? 'default' : 'preserve');
  251.     const localCollapseMultipleSpaces = spaceStyle == 'default';
  253.     // Parse any nested cues first.
  254.     const isLeafNode = cueElement.children.every(TXml.isText);
  255.     const nestedCues = [];
  256.     if (!isLeafNode) {
  257.       // Otherwise, recurse into the children.  Text nodes will convert into
  258.       // anonymous spans, which will then be leaf nodes.
  259.       for (const childNode of cueElement.children) {
  260.         const nestedCue = shaka.text.TtmlTextParser.parseCue_(
  261.             childNode,
  262.             timeContext,
  263.             rateInfo,
  264.             metadataElements,
  265.             styles,
  266.             regionElements,
  267.             cueRegions,
  268.             localCollapseMultipleSpaces,
  269.             cellResolution,
  270.             cueElement,
  271.             isContent,
  272.             uri,
  273.         );
  275.         // This node may or may not generate a nested cue.
  276.         if (nestedCue) {
  277.           nestedCues.push(nestedCue);
  278.         }
  279.       }
  280.     }
  282.     const isNested = /** @type {boolean} */ (parentCueElement != null);
  284.     const textContent = TXml.getTextContents(cueElement);
  285.     // In this regex, "\S" means "non-whitespace character".
  286.     const hasTextContent = cueElement.children.length &&
  287.         textContent &&
  288.         /\S/.test(textContent);
  290.     const hasTimeAttributes =
  291.         cueElement.attributes['begin'] ||
  292.         cueElement.attributes['end'] ||
  293.         cueElement.attributes['dur'];
  295.     if (!hasTimeAttributes && !hasTextContent && cueElement.tagName != 'br' &&
  296.         nestedCues.length == 0) {
  297.       if (!isNested) {
  298.         // Disregards empty <p> elements without time attributes nor content.
  299.         // <p begin="..." smpte:backgroundImage="..." /> will go through,
  300.         // as some information could be held by its attributes.
  301.         // <p /> won't, as it would not be displayed.
  302.         return null;
  303.       } else if (localCollapseMultipleSpaces) {
  304.         // Disregards empty anonymous spans when (local) trim is true.
  305.         return null;
  306.       }
  307.     }
  309.     // Get local time attributes.
  310.     let {start, end} = shaka.text.TtmlTextParser.parseTime_(
  311.         cueElement, rateInfo);
  312.     // Resolve local time relative to parent elements.  Time elements can appear
  313.     // all the way up to 'body', but not 'tt'.
  314.     while (parentElement && TXml.isNode(parentElement) &&
  315.         parentElement.tagName != 'tt') {
  316.       ({start, end} = shaka.text.TtmlTextParser.resolveTime_(
  317.           parentElement, rateInfo, start, end));
  318.       parentElement =
  319.         /** @type {shaka.extern.xml.Node} */ (parentElement.parent);
  320.     }
  322.     if (start == null) {
  323.       start = 0;
  324.     }
  325.     start += timeContext.periodStart;
  327.     // If end is null, that means the duration is effectively infinite.
  328.     if (end == null) {
  329.       end = Infinity;
  330.     } else {
  331.       end += timeContext.periodStart;
  332.     }
  334.     // Clip times to segment boundaries.
  335.     // https://github.com/shaka-project/shaka-player/issues/4631
  336.     start = Math.max(start, timeContext.segmentStart);
  337.     end = Math.min(end, timeContext.segmentEnd);
  339.     if (!hasTimeAttributes && nestedCues.length > 0) {
  340.       // If no time is defined for this cue, base the timing information on
  341.       // the time of the nested cues. In the case of multiple nested cues with
  342.       // different start times, it is the text displayer's responsibility to
  343.       // make sure that only the appropriate nested cue is drawn at any given
  344.       // time.
  345.       start = Infinity;
  346.       end = 0;
  347.       for (const cue of nestedCues) {
  348.         start = Math.min(start, cue.startTime);
  349.         end = Math.max(end, cue.endTime);
  350.       }
  351.     }
  353.     if (cueElement.tagName == 'br') {
  354.       const cue = new shaka.text.Cue(start, end, '');
  355.       cue.lineBreak = true;
  356.       return cue;
  357.     }
  359.     let payload = '';
  360.     if (isLeafNode) {
  361.       // If the childNodes are all text, this is a leaf node.  Get the payload.
  362.       payload = StringUtils.htmlUnescape(
  363.           shaka.util.TXml.getTextContents(cueElement) || '');
  364.       if (localCollapseMultipleSpaces) {
  365.         // Collapse multiple spaces into one.
  366.         payload = payload.replace(/\s+/g, ' ');
  367.       }
  368.     }
  370.     const cue = new shaka.text.Cue(start, end, payload);
  371.     cue.nestedCues = nestedCues;
  373.     if (!isContent) {
  374.       // If this is not a <p> element or a <div> with images, and it has no
  375.       // parent that was a <p> element, then it's part of the outer containers
  376.       // (e.g. the <body> or a normal <div> element within it).
  377.       cue.isContainer = true;
  378.     }
  380.     if (cellResolution) {
  381.       cue.cellResolution = cellResolution;
  382.     }
  384.     // Get other properties if available.
  385.     const regionElement = shaka.text.TtmlTextParser.getElementsFromCollection_(
  386.         cueElement, 'region', regionElements, /* prefix= */ '')[0];
  387.     // Do not actually apply that region unless it is non-inherited, though.
  388.     // This makes it so that, if a parent element has a region, the children
  389.     // don't also all independently apply the positioning of that region.
  390.     if (cueElement.attributes['region']) {
  391.       if (regionElement && regionElement.attributes['xml:id']) {
  392.         const regionId = regionElement.attributes['xml:id'];
  393.         cue.region = cueRegions.filter((region) => region.id == regionId)[0];
  394.       }
  395.     }
  397.     let regionElementForStyle = regionElement;
  398.     if (parentCueElement && isNested && !cueElement.attributes['region'] &&
  399.       !cueElement.attributes['style']) {
  400.       regionElementForStyle =
  401.           shaka.text.TtmlTextParser.getElementsFromCollection_(
  402.               parentCueElement, 'region', regionElements, /* prefix= */ '')[0];
  403.     }
  405.     shaka.text.TtmlTextParser.addStyle_(
  406.         cue,
  407.         cueElement,
  408.         regionElementForStyle,
  409.         /** @type {!shaka.extern.xml.Node} */(imageElement),
  410.         imageUri,
  411.         styles,
  412.         /** isNested= */ parentIsContent, // "nested in a <div>" doesn't count.
  413.         /** isLeaf= */ (nestedCues.length == 0));
  415.     return cue;
  416.   }
  418.   /**
  419.    * Parses an Element into a TextTrackCue or VTTCue.
  420.    *
  421.    * @param {!shaka.extern.xml.Node} regionElement
  422.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  423.    * Defined in the top of tt element and used principally for images.
  424.    * @param {?string} globalExtent
  425.    * @return {shaka.text.CueRegion}
  426.    * @private
  427.    */
  428.   static parseCueRegion_(regionElement, styles, globalExtent) {
  429.     const TtmlTextParser = shaka.text.TtmlTextParser;
  430.     const region = new shaka.text.CueRegion();
  431.     const id = regionElement.attributes['xml:id'];
  432.     if (!id) {
  433.       shaka.log.warning('TtmlTextParser parser encountered a region with ' +
  434.                         'no id. Region will be ignored.');
  435.       return null;
  436.     }
  437.     region.id = id;
  439.     let globalResults = null;
  440.     if (globalExtent) {
  441.       globalResults = TtmlTextParser.percentValues_.exec(globalExtent) ||
  442.         TtmlTextParser.pixelValues_.exec(globalExtent);
  443.     }
  444.     const globalWidth = globalResults ? Number(globalResults[1]) : null;
  445.     const globalHeight = globalResults ? Number(globalResults[2]) : null;
  447.     let results = null;
  448.     let percentage = null;
  449.     const extent = TtmlTextParser.getStyleAttributeFromRegion_(
  450.         regionElement, styles, 'extent');
  451.     if (extent) {
  452.       percentage = TtmlTextParser.percentValues_.exec(extent);
  453.       results = percentage || TtmlTextParser.pixelValues_.exec(extent);
  454.       if (results != null) {
  455.         region.width = Number(results[1]);
  456.         region.height = Number(results[2]);
  458.         if (!percentage) {
  459.           if (globalWidth != null) {
  460.             region.width = region.width * 100 / globalWidth;
  461.           }
  462.           if (globalHeight != null) {
  463.             region.height = region.height * 100 / globalHeight;
  464.           }
  465.         }
  467.         region.widthUnits = percentage || globalWidth != null ?
  468.                            shaka.text.CueRegion.units.PERCENTAGE :
  469.                            shaka.text.CueRegion.units.PX;
  471.         region.heightUnits = percentage || globalHeight != null ?
  472.                            shaka.text.CueRegion.units.PERCENTAGE :
  473.                            shaka.text.CueRegion.units.PX;
  474.       }
  475.     }
  477.     const origin = TtmlTextParser.getStyleAttributeFromRegion_(
  478.         regionElement, styles, 'origin');
  479.     if (origin) {
  480.       percentage = TtmlTextParser.percentValues_.exec(origin);
  481.       results = percentage || TtmlTextParser.pixelValues_.exec(origin);
  482.       if (results != null) {
  483.         region.viewportAnchorX = Number(results[1]);
  484.         region.viewportAnchorY = Number(results[2]);
  486.         if (!percentage) {
  487.           if (globalHeight != null) {
  488.             region.viewportAnchorY = region.viewportAnchorY * 100 /
  489.               globalHeight;
  490.           }
  491.           if (globalWidth != null) {
  492.             region.viewportAnchorX = region.viewportAnchorX * 100 /
  493.               globalWidth;
  494.           }
  495.         } else if (!extent) {
  496.           region.width = 100 - region.viewportAnchorX;
  497.           region.widthUnits = shaka.text.CueRegion.units.PERCENTAGE;
  498.           region.height = 100 - region.viewportAnchorY;
  499.           region.heightUnits = shaka.text.CueRegion.units.PERCENTAGE;
  500.         }
  502.         region.viewportAnchorUnits = percentage || globalWidth != null ?
  503.                   shaka.text.CueRegion.units.PERCENTAGE :
  504.                   shaka.text.CueRegion.units.PX;
  505.       }
  506.     }
  508.     return region;
  509.   }
  511.   /**
  512.    * Adds applicable style properties to a cue.
  513.    *
  514.    * @param {!shaka.text.Cue} cue
  515.    * @param {!shaka.extern.xml.Node} cueElement
  516.    * @param {shaka.extern.xml.Node} region
  517.    * @param {shaka.extern.xml.Node} imageElement
  518.    * @param {?string} imageUri
  519.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  520.    * @param {boolean} isNested
  521.    * @param {boolean} isLeaf
  522.    * @private
  523.    */
  524.   static addStyle_(
  525.       cue, cueElement, region, imageElement, imageUri, styles,
  526.       isNested, isLeaf) {
  527.     const TtmlTextParser = shaka.text.TtmlTextParser;
  528.     const TXml = shaka.util.TXml;
  529.     const Cue = shaka.text.Cue;
  531.     // Styles should be inherited from regions, if a style property is not
  532.     // associated with a Content element (or an anonymous span).
  533.     const shouldInheritRegionStyles = isNested || isLeaf;
  535.     const direction = TtmlTextParser.getStyleAttribute_(
  536.         cueElement, region, styles, 'direction', shouldInheritRegionStyles);
  537.     if (direction == 'rtl') {
  538.       cue.direction = Cue.direction.HORIZONTAL_RIGHT_TO_LEFT;
  539.     }
  541.     // Direction attribute specifies one-dimentional writing direction
  542.     // (left to right or right to left). Writing mode specifies that
  543.     // plus whether text is vertical or horizontal.
  544.     // They should not contradict each other. If they do, we give
  545.     // preference to writing mode.
  546.     const writingMode = TtmlTextParser.getStyleAttribute_(
  547.         cueElement, region, styles, 'writingMode', shouldInheritRegionStyles);
  548.     // Set cue's direction if the text is horizontal, and cue's writingMode if
  549.     // it's vertical.
  550.     if (writingMode == 'tb' || writingMode == 'tblr') {
  551.       cue.writingMode = Cue.writingMode.VERTICAL_LEFT_TO_RIGHT;
  552.     } else if (writingMode == 'tbrl') {
  553.       cue.writingMode = Cue.writingMode.VERTICAL_RIGHT_TO_LEFT;
  554.     } else if (writingMode == 'rltb' || writingMode == 'rl') {
  555.       cue.direction = Cue.direction.HORIZONTAL_RIGHT_TO_LEFT;
  556.     } else if (writingMode) {
  557.       cue.direction = Cue.direction.HORIZONTAL_LEFT_TO_RIGHT;
  558.     }
  560.     const align = TtmlTextParser.getStyleAttribute_(
  561.         cueElement, region, styles, 'textAlign', true);
  562.     if (align) {
  563.       cue.positionAlign = TtmlTextParser.textAlignToPositionAlign_[align];
  564.       cue.lineAlign = TtmlTextParser.textAlignToLineAlign_[align];
  566.       goog.asserts.assert(align.toUpperCase() in Cue.textAlign,
  567.           align.toUpperCase() + ' Should be in Cue.textAlign values!');
  569.       cue.textAlign = Cue.textAlign[align.toUpperCase()];
  570.     } else {
  571.       // Default value is START in the TTML spec: https://bit.ly/32OGmvo
  572.       // But to make the subtitle render consitent with other players and the
  573.       // shaka.text.Cue we use CENTER
  574.       cue.textAlign = Cue.textAlign.CENTER;
  575.     }
  577.     const displayAlign = TtmlTextParser.getStyleAttribute_(
  578.         cueElement, region, styles, 'displayAlign', true);
  579.     if (displayAlign) {
  580.       goog.asserts.assert(displayAlign.toUpperCase() in Cue.displayAlign,
  581.           displayAlign.toUpperCase() +
  582.                           ' Should be in Cue.displayAlign values!');
  583.       cue.displayAlign = Cue.displayAlign[displayAlign.toUpperCase()];
  584.     }
  586.     const color = TtmlTextParser.getStyleAttribute_(
  587.         cueElement, region, styles, 'color', shouldInheritRegionStyles);
  588.     if (color) {
  589.       cue.color = color;
  590.     }
  592.     // Background color should not be set on a container.  If this is a nested
  593.     // cue, you can set the background.  If it's a top-level that happens to
  594.     // also be a leaf, you can set the background.
  595.     // See https://github.com/shaka-project/shaka-player/issues/2623
  596.     // This used to be handled in the displayer, but that is confusing.  The Cue
  597.     // structure should reflect what you want to happen in the displayer, and
  598.     // the displayer shouldn't have to know about TTML.
  599.     const backgroundColor = TtmlTextParser.getStyleAttribute_(
  600.         cueElement, region, styles, 'backgroundColor',
  601.         shouldInheritRegionStyles);
  602.     if (backgroundColor) {
  603.       cue.backgroundColor = backgroundColor;
  604.     }
  606.     const border = TtmlTextParser.getStyleAttribute_(
  607.         cueElement, region, styles, 'border', shouldInheritRegionStyles);
  608.     if (border) {
  609.       cue.border = border;
  610.     }
  612.     const fontFamily = TtmlTextParser.getStyleAttribute_(
  613.         cueElement, region, styles, 'fontFamily', shouldInheritRegionStyles);
  614.     // See https://github.com/sandflow/imscJS/blob/1.1.3/src/main/js/html.js#L1384
  615.     if (fontFamily) {
  616.       switch (fontFamily) {
  617.         case 'monospaceSerif':
  618.           cue.fontFamily = 'Courier New,Liberation Mono,Courier,monospace';
  619.           break;
  620.         case 'proportionalSansSerif':
  621.           cue.fontFamily = 'Arial,Helvetica,Liberation Sans,sans-serif';
  622.           break;
  623.         case 'sansSerif':
  624.           cue.fontFamily = 'sans-serif';
  625.           break;
  626.         case 'monospaceSansSerif':
  627.           cue.fontFamily = 'Consolas,monospace';
  628.           break;
  629.         case 'proportionalSerif':
  630.           cue.fontFamily = 'serif';
  631.           break;
  632.         default:
  633.           cue.fontFamily = fontFamily;
  634.           break;
  635.       }
  636.     }
  638.     const fontWeight = TtmlTextParser.getStyleAttribute_(
  639.         cueElement, region, styles, 'fontWeight', shouldInheritRegionStyles);
  640.     if (fontWeight && fontWeight == 'bold') {
  641.       cue.fontWeight = Cue.fontWeight.BOLD;
  642.     }
  644.     const wrapOption = TtmlTextParser.getStyleAttribute_(
  645.         cueElement, region, styles, 'wrapOption', shouldInheritRegionStyles);
  646.     if (wrapOption && wrapOption == 'noWrap') {
  647.       cue.wrapLine = false;
  648.     } else {
  649.       cue.wrapLine = true;
  650.     }
  652.     const lineHeight = TtmlTextParser.getStyleAttribute_(
  653.         cueElement, region, styles, 'lineHeight', shouldInheritRegionStyles);
  654.     if (lineHeight && lineHeight.match(TtmlTextParser.unitValues_)) {
  655.       cue.lineHeight = lineHeight;
  656.     }
  658.     const fontSize = TtmlTextParser.getStyleAttribute_(
  659.         cueElement, region, styles, 'fontSize', shouldInheritRegionStyles);
  660.     if (fontSize) {
  661.       const isValidFontSizeUnit =
  662.           fontSize.match(TtmlTextParser.unitValues_) ||
  663.           fontSize.match(TtmlTextParser.percentValue_);
  665.       if (isValidFontSizeUnit) {
  666.         cue.fontSize = fontSize;
  667.       }
  668.     }
  670.     const fontStyle = TtmlTextParser.getStyleAttribute_(
  671.         cueElement, region, styles, 'fontStyle', shouldInheritRegionStyles);
  672.     if (fontStyle) {
  673.       goog.asserts.assert(fontStyle.toUpperCase() in Cue.fontStyle,
  674.           fontStyle.toUpperCase() +
  675.                           ' Should be in Cue.fontStyle values!');
  676.       cue.fontStyle = Cue.fontStyle[fontStyle.toUpperCase()];
  677.     }
  679.     if (imageElement) {
  680.       // According to the spec, we should use imageType (camelCase), but
  681.       // historically we have checked for imagetype (lowercase).
  682.       // This was the case since background image support was first introduced
  683.       // in PR #1859, in April 2019, and first released in v2.5.0.
  684.       // Now we check for both, although only imageType (camelCase) is to spec.
  685.       const backgroundImageType =
  686.           imageElement.attributes['imageType'] ||
  687.           imageElement.attributes['imagetype'];
  688.       const backgroundImageEncoding = imageElement.attributes['encoding'];
  689.       const backgroundImageData = (TXml.getTextContents(imageElement)).trim();
  690.       if (backgroundImageType == 'PNG' &&
  691.           backgroundImageEncoding == 'Base64' &&
  692.           backgroundImageData) {
  693.         cue.backgroundImage = 'data:image/png;base64,' + backgroundImageData;
  694.       }
  695.     } else if (imageUri) {
  696.       cue.backgroundImage = imageUri;
  697.     }
  699.     const textOutline = TtmlTextParser.getStyleAttribute_(
  700.         cueElement, region, styles, 'textOutline', shouldInheritRegionStyles);
  701.     if (textOutline) {
  702.       // tts:textOutline isn't natively supported by browsers, but it can be
  703.       // mostly replicated using the non-standard -webkit-text-stroke-width and
  704.       // -webkit-text-stroke-color properties.
  705.       const split = textOutline.split(' ');
  706.       if (split[0].match(TtmlTextParser.unitValues_)) {
  707.         // There is no defined color, so default to the text color.
  708.         cue.textStrokeColor = cue.color;
  709.       } else {
  710.         cue.textStrokeColor = split[0];
  711.         split.shift();
  712.       }
  713.       if (split[0] && split[0].match(TtmlTextParser.unitValues_)) {
  714.         cue.textStrokeWidth = split[0];
  715.       } else {
  716.         // If there is no width, or the width is not a number, don't draw a
  717.         // border.
  718.         cue.textStrokeColor = '';
  719.       }
  720.       // There is an optional blur radius also, but we have no way of
  721.       // replicating that, so ignore it.
  722.     }
  724.     const letterSpacing = TtmlTextParser.getStyleAttribute_(
  725.         cueElement, region, styles, 'letterSpacing', shouldInheritRegionStyles);
  726.     if (letterSpacing && letterSpacing.match(TtmlTextParser.unitValues_)) {
  727.       cue.letterSpacing = letterSpacing;
  728.     }
  730.     const linePadding = TtmlTextParser.getStyleAttribute_(
  731.         cueElement, region, styles, 'linePadding', shouldInheritRegionStyles);
  732.     if (linePadding && linePadding.match(TtmlTextParser.unitValues_)) {
  733.       cue.linePadding = linePadding;
  734.     }
  736.     const opacity = TtmlTextParser.getStyleAttribute_(
  737.         cueElement, region, styles, 'opacity', shouldInheritRegionStyles);
  738.     if (opacity) {
  739.       cue.opacity = parseFloat(opacity);
  740.     }
  742.     // Text decoration is an array of values which can come both from the
  743.     // element's style or be inherited from elements' parent nodes. All of those
  744.     // values should be applied as long as they don't contradict each other. If
  745.     // they do, elements' own style gets preference.
  746.     const textDecorationRegion = TtmlTextParser.getStyleAttributeFromRegion_(
  747.         region, styles, 'textDecoration');
  748.     if (textDecorationRegion) {
  749.       TtmlTextParser.addTextDecoration_(cue, textDecorationRegion);
  750.     }
  752.     const textDecorationElement = TtmlTextParser.getStyleAttributeFromElement_(
  753.         cueElement, styles, 'textDecoration');
  754.     if (textDecorationElement) {
  755.       TtmlTextParser.addTextDecoration_(cue, textDecorationElement);
  756.     }
  758.     const textCombine = TtmlTextParser.getStyleAttribute_(
  759.         cueElement, region, styles, 'textCombine', shouldInheritRegionStyles);
  760.     if (textCombine) {
  761.       cue.textCombineUpright = textCombine;
  762.     }
  764.     const ruby = TtmlTextParser.getStyleAttribute_(
  765.         cueElement, region, styles, 'ruby', shouldInheritRegionStyles);
  766.     switch (ruby) {
  767.       case 'container':
  768.         cue.rubyTag = 'ruby';
  769.         break;
  770.       case 'text':
  771.         cue.rubyTag = 'rt';
  772.         break;
  773.     }
  774.   }
  776.   /**
  777.    * Parses text decoration values and adds/removes them to/from the cue.
  778.    *
  779.    * @param {!shaka.text.Cue} cue
  780.    * @param {string} decoration
  781.    * @private
  782.    */
  783.   static addTextDecoration_(cue, decoration) {
  784.     const Cue = shaka.text.Cue;
  785.     for (const value of decoration.split(' ')) {
  786.       switch (value) {
  787.         case 'underline':
  788.           if (!cue.textDecoration.includes(Cue.textDecoration.UNDERLINE)) {
  789.             cue.textDecoration.push(Cue.textDecoration.UNDERLINE);
  790.           }
  791.           break;
  792.         case 'noUnderline':
  793.           if (cue.textDecoration.includes(Cue.textDecoration.UNDERLINE)) {
  794.             shaka.util.ArrayUtils.remove(cue.textDecoration,
  795.                 Cue.textDecoration.UNDERLINE);
  796.           }
  797.           break;
  798.         case 'lineThrough':
  799.           if (!cue.textDecoration.includes(Cue.textDecoration.LINE_THROUGH)) {
  800.             cue.textDecoration.push(Cue.textDecoration.LINE_THROUGH);
  801.           }
  802.           break;
  803.         case 'noLineThrough':
  804.           if (cue.textDecoration.includes(Cue.textDecoration.LINE_THROUGH)) {
  805.             shaka.util.ArrayUtils.remove(cue.textDecoration,
  806.                 Cue.textDecoration.LINE_THROUGH);
  807.           }
  808.           break;
  809.         case 'overline':
  810.           if (!cue.textDecoration.includes(Cue.textDecoration.OVERLINE)) {
  811.             cue.textDecoration.push(Cue.textDecoration.OVERLINE);
  812.           }
  813.           break;
  814.         case 'noOverline':
  815.           if (cue.textDecoration.includes(Cue.textDecoration.OVERLINE)) {
  816.             shaka.util.ArrayUtils.remove(cue.textDecoration,
  817.                 Cue.textDecoration.OVERLINE);
  818.           }
  819.           break;
  820.       }
  821.     }
  822.   }
  824.   /**
  825.    * Finds a specified attribute on either the original cue element or its
  826.    * associated region and returns the value if the attribute was found.
  827.    *
  828.    * @param {!shaka.extern.xml.Node} cueElement
  829.    * @param {shaka.extern.xml.Node} region
  830.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  831.    * @param {string} attribute
  832.    * @param {boolean=} shouldInheritRegionStyles
  833.    * @return {?string}
  834.    * @private
  835.    */
  836.   static getStyleAttribute_(cueElement, region, styles, attribute,
  837.       shouldInheritRegionStyles=true) {
  838.     // An attribute can be specified on region level or in a styling block
  839.     // associated with the region or original element.
  840.     const TtmlTextParser = shaka.text.TtmlTextParser;
  841.     const attr = TtmlTextParser.getStyleAttributeFromElement_(
  842.         cueElement, styles, attribute);
  843.     if (attr) {
  844.       return attr;
  845.     }
  847.     if (shouldInheritRegionStyles) {
  848.       return TtmlTextParser.getStyleAttributeFromRegion_(
  849.           region, styles, attribute);
  850.     }
  851.     return null;
  852.   }
  854.   /**
  855.    * Finds a specified attribute on the element's associated region
  856.    * and returns the value if the attribute was found.
  857.    *
  858.    * @param {shaka.extern.xml.Node} region
  859.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  860.    * @param {string} attribute
  861.    * @return {?string}
  862.    * @private
  863.    */
  864.   static getStyleAttributeFromRegion_(region, styles, attribute) {
  865.     const TXml = shaka.util.TXml;
  866.     const ttsNs = shaka.text.TtmlTextParser.styleNs_;
  868.     if (!region) {
  869.       return null;
  870.     }
  872.     const attr = TXml.getAttributeNSList(region, ttsNs, attribute);
  873.     if (attr) {
  874.       return attr;
  875.     }
  877.     return shaka.text.TtmlTextParser.getInheritedStyleAttribute_(
  878.         region, styles, attribute);
  879.   }
  881.   /**
  882.    * Finds a specified attribute on the cue element and returns the value
  883.    * if the attribute was found.
  884.    *
  885.    * @param {!shaka.extern.xml.Node} cueElement
  886.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  887.    * @param {string} attribute
  888.    * @return {?string}
  889.    * @private
  890.    */
  891.   static getStyleAttributeFromElement_(cueElement, styles, attribute) {
  892.     const TXml = shaka.util.TXml;
  893.     const ttsNs = shaka.text.TtmlTextParser.styleNs_;
  895.     // Styling on elements should take precedence
  896.     // over the main styling attributes
  897.     const elementAttribute = TXml.getAttributeNSList(
  898.         cueElement,
  899.         ttsNs,
  900.         attribute);
  902.     if (elementAttribute) {
  903.       return elementAttribute;
  904.     }
  905.     return shaka.text.TtmlTextParser.getInheritedStyleAttribute_(
  906.         cueElement, styles, attribute);
  907.   }
  909.   /**
  910.    * Finds a specified attribute on an element's styles and the styles those
  911.    * styles inherit from.
  912.    *
  913.    * @param {!shaka.extern.xml.Node} element
  914.    * @param {!Array.<!shaka.extern.xml.Node>} styles
  915.    * @param {string} attribute
  916.    * @return {?string}
  917.    * @private
  918.    */
  919.   static getInheritedStyleAttribute_(element, styles, attribute) {
  920.     const TXml = shaka.util.TXml;
  921.     const ttsNs = shaka.text.TtmlTextParser.styleNs_;
  922.     const ebuttsNs = shaka.text.TtmlTextParser.styleEbuttsNs_;
  924.     const inheritedStyles =
  925.         shaka.text.TtmlTextParser.getElementsFromCollection_(
  926.             element, 'style', styles, /* prefix= */ '');
  928.     let styleValue = null;
  930.     // The last value in our styles stack takes the precedence over the others
  931.     for (let i = 0; i < inheritedStyles.length; i++) {
  932.       // Check ebu namespace first.
  933.       let styleAttributeValue = TXml.getAttributeNS(
  934.           inheritedStyles[i],
  935.           ebuttsNs,
  936.           attribute);
  938.       if (!styleAttributeValue) {
  939.         // Fall back to tts namespace.
  940.         styleAttributeValue = TXml.getAttributeNSList(
  941.             inheritedStyles[i],
  942.             ttsNs,
  943.             attribute);
  944.       }
  946.       if (!styleAttributeValue) {
  947.         // Next, check inheritance.
  948.         // Styles can inherit from other styles, so traverse up that chain.
  949.         styleAttributeValue =
  950.             shaka.text.TtmlTextParser.getStyleAttributeFromElement_(
  951.                 inheritedStyles[i], styles, attribute);
  952.       }
  954.       if (styleAttributeValue) {
  955.         styleValue = styleAttributeValue;
  956.       }
  957.     }
  959.     return styleValue;
  960.   }
  963.   /**
  964.    * Selects items from |collection| whose id matches |attributeName|
  965.    * from |element|.
  966.    *
  967.    * @param {shaka.extern.xml.Node} element
  968.    * @param {string} attributeName
  969.    * @param {!Array.<shaka.extern.xml.Node>} collection
  970.    * @param {string} prefixName
  971.    * @param {string=} nsName
  972.    * @return {!Array.<!shaka.extern.xml.Node>}
  973.    * @private
  974.    */
  975.   static getElementsFromCollection_(
  976.       element, attributeName, collection, prefixName, nsName) {
  977.     const items = [];
  979.     if (!element || collection.length < 1) {
  980.       return items;
  981.     }
  983.     const attributeValue = shaka.text.TtmlTextParser.getInheritedAttribute_(
  984.         element, attributeName, nsName);
  986.     if (attributeValue) {
  987.       // There could be multiple items in one attribute
  988.       // <span style="style1 style2">A cue</span>
  989.       const itemNames = attributeValue.split(' ');
  991.       for (const name of itemNames) {
  992.         for (const item of collection) {
  993.           if ((prefixName + item.attributes['xml:id']) == name) {
  994.             items.push(item);
  995.             break;
  996.           }
  997.         }
  998.       }
  999.     }
  1001.     return items;
  1002.   }
  1005.   /**
  1006.    * Traverses upwards from a given node until a given attribute is found.
  1007.    *
  1008.    * @param {!shaka.extern.xml.Node} element
  1009.    * @param {string} attributeName
  1010.    * @param {string=} nsName
  1011.    * @return {?string}
  1012.    * @private
  1013.    */
  1014.   static getInheritedAttribute_(element, attributeName, nsName) {
  1015.     let ret = null;
  1016.     const TXml = shaka.util.TXml;
  1017.     while (!ret) {
  1018.       ret = nsName ?
  1019.           TXml.getAttributeNS(element, nsName, attributeName) :
  1020.           element.attributes[attributeName];
  1021.       if (ret) {
  1022.         break;
  1023.       }
  1025.       // Element.parentNode can lead to XMLDocument, which is not an Element and
  1026.       // has no getAttribute().
  1027.       const parentNode = element.parent;
  1028.       if (parentNode) {
  1029.         element = parentNode;
  1030.       } else {
  1031.         break;
  1032.       }
  1033.     }
  1034.     return ret;
  1035.   }
  1037.   /**
  1038.    * Factor parent/ancestor time attributes into the parsed time of a
  1039.    * child/descendent.
  1040.    *
  1041.    * @param {!shaka.extern.xml.Node} parentElement
  1042.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1043.    * @param {?number} start The child's start time
  1044.    * @param {?number} end The child's end time
  1045.    * @return {{start: ?number, end: ?number}}
  1046.    * @private
  1047.    */
  1048.   static resolveTime_(parentElement, rateInfo, start, end) {
  1049.     const parentTime = shaka.text.TtmlTextParser.parseTime_(
  1050.         parentElement, rateInfo);
  1052.     if (start == null) {
  1053.       // No start time of your own?  Inherit from the parent.
  1054.       start = parentTime.start;
  1055.     } else {
  1056.       // Otherwise, the start time is relative to the parent's start time.
  1057.       if (parentTime.start != null) {
  1058.         start += parentTime.start;
  1059.       }
  1060.     }
  1062.     if (end == null) {
  1063.       // No end time of your own?  Inherit from the parent.
  1064.       end = parentTime.end;
  1065.     } else {
  1066.       // Otherwise, the end time is relative to the parent's _start_ time.
  1067.       // This is not a typo.  Both times are relative to the parent's _start_.
  1068.       if (parentTime.start != null) {
  1069.         end += parentTime.start;
  1070.       }
  1071.     }
  1073.     return {start, end};
  1074.   }
  1076.   /**
  1077.    * Parse TTML time attributes from the given element.
  1078.    *
  1079.    * @param {!shaka.extern.xml.Node} element
  1080.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1081.    * @return {{start: ?number, end: ?number}}
  1082.    * @private
  1083.    */
  1084.   static parseTime_(element, rateInfo) {
  1085.     const start = shaka.text.TtmlTextParser.parseTimeAttribute_(
  1086.         element.attributes['begin'], rateInfo);
  1087.     let end = shaka.text.TtmlTextParser.parseTimeAttribute_(
  1088.         element.attributes['end'], rateInfo);
  1089.     const duration = shaka.text.TtmlTextParser.parseTimeAttribute_(
  1090.         element.attributes['dur'], rateInfo);
  1091.     if (end == null && duration != null) {
  1092.       end = start + duration;
  1093.     }
  1094.     return {start, end};
  1095.   }
  1097.   /**
  1098.    * Parses a TTML time from the given attribute text.
  1099.    *
  1100.    * @param {string} text
  1101.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1102.    * @return {?number}
  1103.    * @private
  1104.    */
  1105.   static parseTimeAttribute_(text, rateInfo) {
  1106.     let ret = null;
  1107.     const TtmlTextParser = shaka.text.TtmlTextParser;
  1109.     if (TtmlTextParser.timeColonFormatFrames_.test(text)) {
  1110.       ret = TtmlTextParser.parseColonTimeWithFrames_(rateInfo, text);
  1111.     } else if (TtmlTextParser.timeColonFormat_.test(text)) {
  1112.       ret = TtmlTextParser.parseTimeFromRegex_(
  1113.           TtmlTextParser.timeColonFormat_, text);
  1114.     } else if (TtmlTextParser.timeColonFormatMilliseconds_.test(text)) {
  1115.       ret = TtmlTextParser.parseTimeFromRegex_(
  1116.           TtmlTextParser.timeColonFormatMilliseconds_, text);
  1117.     } else if (TtmlTextParser.timeFramesFormat_.test(text)) {
  1118.       ret = TtmlTextParser.parseFramesTime_(rateInfo, text);
  1119.     } else if (TtmlTextParser.timeTickFormat_.test(text)) {
  1120.       ret = TtmlTextParser.parseTickTime_(rateInfo, text);
  1121.     } else if (TtmlTextParser.timeHMSFormat_.test(text)) {
  1122.       ret = TtmlTextParser.parseTimeFromRegex_(
  1123.           TtmlTextParser.timeHMSFormat_, text);
  1124.     } else if (text) {
  1125.       // It's not empty or null, but it doesn't match a known format.
  1126.       throw new shaka.util.Error(
  1127.           shaka.util.Error.Severity.CRITICAL,
  1128.           shaka.util.Error.Category.TEXT,
  1129.           shaka.util.Error.Code.INVALID_TEXT_CUE,
  1130.           'Could not parse cue time range in TTML');
  1131.     }
  1133.     return ret;
  1134.   }
  1136.   /**
  1137.    * Parses a TTML time in frame format.
  1138.    *
  1139.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1140.    * @param {string} text
  1141.    * @return {?number}
  1142.    * @private
  1143.    */
  1144.   static parseFramesTime_(rateInfo, text) {
  1145.     // 75f or 75.5f
  1146.     const results = shaka.text.TtmlTextParser.timeFramesFormat_.exec(text);
  1147.     const frames = Number(results[1]);
  1149.     return frames / rateInfo.frameRate;
  1150.   }
  1152.   /**
  1153.    * Parses a TTML time in tick format.
  1154.    *
  1155.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1156.    * @param {string} text
  1157.    * @return {?number}
  1158.    * @private
  1159.    */
  1160.   static parseTickTime_(rateInfo, text) {
  1161.     // 50t or 50.5t
  1162.     const results = shaka.text.TtmlTextParser.timeTickFormat_.exec(text);
  1163.     const ticks = Number(results[1]);
  1165.     return ticks / rateInfo.tickRate;
  1166.   }
  1168.   /**
  1169.    * Parses a TTML colon formatted time containing frames.
  1170.    *
  1171.    * @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
  1172.    * @param {string} text
  1173.    * @return {?number}
  1174.    * @private
  1175.    */
  1176.   static parseColonTimeWithFrames_(rateInfo, text) {
  1177.     // 01:02:43:07 ('07' is frames) or 01:02:43:07.1 (subframes)
  1178.     const results = shaka.text.TtmlTextParser.timeColonFormatFrames_.exec(text);
  1180.     const hours = Number(results[1]);
  1181.     const minutes = Number(results[2]);
  1182.     let seconds = Number(results[3]);
  1183.     let frames = Number(results[4]);
  1184.     const subframes = Number(results[5]) || 0;
  1186.     frames += subframes / rateInfo.subFrameRate;
  1187.     seconds += frames / rateInfo.frameRate;
  1189.     return seconds + (minutes * 60) + (hours * 3600);
  1190.   }
  1192.   /**
  1193.    * Parses a TTML time with a given regex. Expects regex to be some
  1194.    * sort of a time-matcher to match hours, minutes, seconds and milliseconds
  1195.    *
  1196.    * @param {!RegExp} regex
  1197.    * @param {string} text
  1198.    * @return {?number}
  1199.    * @private
  1200.    */
  1201.   static parseTimeFromRegex_(regex, text) {
  1202.     const results = regex.exec(text);
  1203.     if (results == null || results[0] == '') {
  1204.       return null;
  1205.     }
  1206.     // This capture is optional, but will still be in the array as undefined,
  1207.     // in which case it is 0.
  1208.     const hours = Number(results[1]) || 0;
  1209.     const minutes = Number(results[2]) || 0;
  1210.     const seconds = Number(results[3]) || 0;
  1211.     const milliseconds = Number(results[4]) || 0;
  1213.     return (milliseconds / 1000) + seconds + (minutes * 60) + (hours * 3600);
  1214.   }
  1216.   /**
  1217.    * If ttp:cellResolution provided returns cell resolution info
  1218.    * with number of columns and rows into which the Root Container
  1219.    * Region area is divided
  1220.    *
  1221.    * @param {?string} cellResolution
  1222.    * @return {?{columns: number, rows: number}}
  1223.    * @private
  1224.    */
  1225.   static getCellResolution_(cellResolution) {
  1226.     if (!cellResolution) {
  1227.       return null;
  1228.     }
  1229.     const matches = /^(\d+) (\d+)$/.exec(cellResolution);
  1231.     if (!matches) {
  1232.       return null;
  1233.     }
  1235.     const columns = parseInt(matches[1], 10);
  1236.     const rows = parseInt(matches[2], 10);
  1238.     return {columns, rows};
  1239.   }
  1240. };
  1242. /**
  1243.  * @summary
  1244.  * Contains information about frame/subframe rate
  1245.  * and frame rate multiplier for time in frame format.
  1246.  *
  1247.  * @example 01:02:03:04(4 frames) or 01:02:03:04.1(4 frames, 1 subframe)
  1248.  * @private
  1249.  */
  1250. shaka.text.TtmlTextParser.RateInfo_ = class {
  1251.   /**
  1252.    * @param {?string} frameRate
  1253.    * @param {?string} subFrameRate
  1254.    * @param {?string} frameRateMultiplier
  1255.    * @param {?string} tickRate
  1256.    */
  1257.   constructor(frameRate, subFrameRate, frameRateMultiplier, tickRate) {
  1258.     /**
  1259.      * @type {number}
  1260.      */
  1261.     this.frameRate = Number(frameRate) || 30;
  1263.     /**
  1264.      * @type {number}
  1265.      */
  1266.     this.subFrameRate = Number(subFrameRate) || 1;
  1268.     /**
  1269.      * @type {number}
  1270.      */
  1271.     this.tickRate = Number(tickRate);
  1272.     if (this.tickRate == 0) {
  1273.       if (frameRate) {
  1274.         this.tickRate = this.frameRate * this.subFrameRate;
  1275.       } else {
  1276.         this.tickRate = 1;
  1277.       }
  1278.     }
  1280.     if (frameRateMultiplier) {
  1281.       const multiplierResults = /^(\d+) (\d+)$/g.exec(frameRateMultiplier);
  1282.       if (multiplierResults) {
  1283.         const numerator = Number(multiplierResults[1]);
  1284.         const denominator = Number(multiplierResults[2]);
  1285.         const multiplierNum = numerator / denominator;
  1286.         this.frameRate *= multiplierNum;
  1287.       }
  1288.     }
  1289.   }
  1290. };
  1292. /**
  1293.  * @const
  1294.  * @private {!RegExp}
  1295.  * @example 50.17% 10%
  1296.  */
  1297. shaka.text.TtmlTextParser.percentValues_ =
  1298.     /^(\d{1,2}(?:\.\d+)?|100(?:\.0+)?)% (\d{1,2}(?:\.\d+)?|100(?:\.0+)?)%$/;
  1300. /**
  1301.  * @const
  1302.  * @private {!RegExp}
  1303.  * @example 0.6% 90%
  1304.  */
  1305. shaka.text.TtmlTextParser.percentValue_ = /^(\d{1,2}(?:\.\d+)?|100)%$/;
  1307. /**
  1308.  * @const
  1309.  * @private {!RegExp}
  1310.  * @example 100px, 8em, 0.80c
  1311.  */
  1312. shaka.text.TtmlTextParser.unitValues_ = /^(\d+px|\d+em|\d*\.?\d+c)$/;
  1314. /**
  1315.  * @const
  1316.  * @private {!RegExp}
  1317.  * @example 100px
  1318.  */
  1319. shaka.text.TtmlTextParser.pixelValues_ = /^(\d+)px (\d+)px$/;
  1321. /**
  1322.  * @const
  1323.  * @private {!RegExp}
  1324.  * @example 00:00:40:07 (7 frames) or 00:00:40:07.1 (7 frames, 1 subframe)
  1325.  */
  1326. shaka.text.TtmlTextParser.timeColonFormatFrames_ =
  1327.     /^(\d{2,}):(\d{2}):(\d{2}):(\d{2})\.?(\d+)?$/;
  1329. /**
  1330.  * @const
  1331.  * @private {!RegExp}
  1332.  * @example 00:00:40 or 00:40
  1333.  */
  1334. shaka.text.TtmlTextParser.timeColonFormat_ = /^(?:(\d{2,}):)?(\d{2}):(\d{2})$/;
  1336. /**
  1337.  * @const
  1338.  * @private {!RegExp}
  1339.  * @example 01:02:43.0345555 or 02:43.03
  1340.  */
  1341. shaka.text.TtmlTextParser.timeColonFormatMilliseconds_ =
  1342.     /^(?:(\d{2,}):)?(\d{2}):(\d{2}\.\d{2,})$/;
  1344. /**
  1345.  * @const
  1346.  * @private {!RegExp}
  1347.  * @example 75f or 75.5f
  1348.  */
  1349. shaka.text.TtmlTextParser.timeFramesFormat_ = /^(\d*(?:\.\d*)?)f$/;
  1351. /**
  1352.  * @const
  1353.  * @private {!RegExp}
  1354.  * @example 50t or 50.5t
  1355.  */
  1356. shaka.text.TtmlTextParser.timeTickFormat_ = /^(\d*(?:\.\d*)?)t$/;
  1358. /**
  1359.  * @const
  1360.  * @private {!RegExp}
  1361.  * @example 3.45h, 3m or 4.20s
  1362.  */
  1363. shaka.text.TtmlTextParser.timeHMSFormat_ =
  1364.     new RegExp(['^(?:(\\d*(?:\\.\\d*)?)h)?',
  1365.       '(?:(\\d*(?:\\.\\d*)?)m)?',
  1366.       '(?:(\\d*(?:\\.\\d*)?)s)?',
  1367.       '(?:(\\d*(?:\\.\\d*)?)ms)?$'].join(''));
  1369. /**
  1370.  * @const
  1371.  * @private {!Object.<string, shaka.text.Cue.lineAlign>}
  1372.  */
  1373. shaka.text.TtmlTextParser.textAlignToLineAlign_ = {
  1374.   'left': shaka.text.Cue.lineAlign.START,
  1375.   'center': shaka.text.Cue.lineAlign.CENTER,
  1376.   'right': shaka.text.Cue.lineAlign.END,
  1377.   'start': shaka.text.Cue.lineAlign.START,
  1378.   'end': shaka.text.Cue.lineAlign.END,
  1379. };
  1381. /**
  1382.  * @const
  1383.  * @private {!Object.<string, shaka.text.Cue.positionAlign>}
  1384.  */
  1385. shaka.text.TtmlTextParser.textAlignToPositionAlign_ = {
  1386.   'left': shaka.text.Cue.positionAlign.LEFT,
  1387.   'center': shaka.text.Cue.positionAlign.CENTER,
  1388.   'right': shaka.text.Cue.positionAlign.RIGHT,
  1389. };
  1391. /**
  1392.  * The namespace URL for TTML parameters.  Can be assigned any name in the TTML
  1393.  * document, not just "ttp:", so we use this with getAttributeNS() to ensure
  1394.  * that we support arbitrary namespace names.
  1395.  *
  1396.  * @const {!Array.<string>}
  1397.  * @private
  1398.  */
  1399. shaka.text.TtmlTextParser.parameterNs_ = [
  1400.   'http://www.w3.org/ns/ttml#parameter',
  1401.   'http://www.w3.org/2006/10/ttaf1#parameter',
  1402. ];
  1404. /**
  1405.  * The namespace URL for TTML styles.  Can be assigned any name in the TTML
  1406.  * document, not just "tts:", so we use this with getAttributeNS() to ensure
  1407.  * that we support arbitrary namespace names.
  1408.  *
  1409.  * @const {!Array.<string>}
  1410.  * @private
  1411.  */
  1412. shaka.text.TtmlTextParser.styleNs_ = [
  1413.   'http://www.w3.org/ns/ttml#styling',
  1414.   'http://www.w3.org/2006/10/ttaf1#styling',
  1415. ];
  1417. /**
  1418.  * The namespace URL for EBU TTML styles.  Can be assigned any name in the TTML
  1419.  * document, not just "ebutts:", so we use this with getAttributeNS() to ensure
  1420.  * that we support arbitrary namespace names.
  1421.  *
  1422.  * @const {string}
  1423.  * @private
  1424.  */
  1425. shaka.text.TtmlTextParser.styleEbuttsNs_ = 'urn:ebu:tt:style';
  1427. /**
  1428.  * The supported namespace URLs for SMPTE fields.
  1429.  * @const {!Array.<string>}
  1430.  * @private
  1431.  */
  1432. shaka.text.TtmlTextParser.smpteNsList_ = [
  1433.   'http://www.smpte-ra.org/schemas/2052-1/2010/smpte-tt',
  1434.   'http://www.smpte-ra.org/schemas/2052-1/2013/smpte-tt',
  1435. ];
  1437. shaka.text.TextEngine.registerParser(
  1438.     'application/ttml+xml', () => new shaka.text.TtmlTextParser());