/**
* @license
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
goog.provide('shaka.text.TtmlTextParser');
goog.require('goog.asserts');
goog.require('shaka.text.Cue');
goog.require('shaka.text.TextEngine');
goog.require('shaka.util.ArrayUtils');
goog.require('shaka.util.Error');
goog.require('shaka.util.StringUtils');
/**
* @constructor
* @implements {shakaExtern.TextParser}
*/
shaka.text.TtmlTextParser = function() {};
/** @override */
shaka.text.TtmlTextParser.prototype.parseInit = function(data) {
goog.asserts.assert(false, 'TTML does not have init segments');
};
/** @override */
shaka.text.TtmlTextParser.prototype.parseMedia = function(data, time) {
var str = shaka.util.StringUtils.fromUTF8(data);
var ret = [];
var parser = new DOMParser();
var xml = null;
try {
xml = parser.parseFromString(str, 'text/xml');
} catch (exception) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.TEXT,
shaka.util.Error.Code.INVALID_XML);
}
if (xml) {
// Try to get the framerate, subFrameRate and frameRateMultiplier
// if applicable
var frameRate = null;
var subFrameRate = null;
var frameRateMultiplier = null;
var tickRate = null;
var spaceStyle = null;
var tts = xml.getElementsByTagName('tt');
var tt = tts[0];
// TTML should always have tt element
if (!tt) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.TEXT,
shaka.util.Error.Code.INVALID_XML);
} else {
frameRate = tt.getAttribute('ttp:frameRate');
subFrameRate = tt.getAttribute('ttp:subFrameRate');
frameRateMultiplier = tt.getAttribute('ttp:frameRateMultiplier');
tickRate = tt.getAttribute('ttp:tickRate');
spaceStyle = tt.getAttribute('xml:space') || 'default';
}
if (spaceStyle != 'default' && spaceStyle != 'preserve') {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.TEXT,
shaka.util.Error.Code.INVALID_XML);
}
var whitespaceTrim = spaceStyle == 'default';
var rateInfo = new shaka.text.TtmlTextParser.RateInfo_(
frameRate, subFrameRate, frameRateMultiplier, tickRate);
var styles = shaka.text.TtmlTextParser.getLeafNodes_(
tt.getElementsByTagName('styling')[0]);
var regions = shaka.text.TtmlTextParser.getLeafNodes_(
tt.getElementsByTagName('layout')[0]);
var textNodes = shaka.text.TtmlTextParser.getLeafNodes_(
tt.getElementsByTagName('body')[0]);
for (var i = 0; i < textNodes.length; i++) {
var cue = shaka.text.TtmlTextParser.parseCue_(textNodes[i],
time.periodStart,
rateInfo,
styles,
regions,
whitespaceTrim);
if (cue)
ret.push(cue);
}
}
return ret;
};
/**
* @const
* @private {!RegExp}
* @example 00:00:40:07 (7 frames) or 00:00:40:07.1 (7 frames, 1 subframe)
*/
shaka.text.TtmlTextParser.timeColonFormatFrames_ =
/^(\d{2,}):(\d{2}):(\d{2}):(\d{2})\.?(\d+)?$/;
/**
* @const
* @private {!RegExp}
* @example 00:00:40 or 00:40
*/
shaka.text.TtmlTextParser.timeColonFormat_ =
/^(?:(\d{2,}):)?(\d{2}):(\d{2})$/;
/**
* @const
* @private {!RegExp}
* example 01:02:43.0345555 or 02:43.03
*/
shaka.text.TtmlTextParser.timeColonFormatMilliseconds_ =
/^(?:(\d{2,}):)?(\d{2}):(\d{2}\.\d{2,})$/;
/**
* @const
* @private {!RegExp}
* @example 75f or 75.5f
*/
shaka.text.TtmlTextParser.timeFramesFormat_ = /^(\d*\.?\d*)f$/;
/**
* @const
* @private {!RegExp}
* @example 50t or 50.5t
*/
shaka.text.TtmlTextParser.timeTickFormat_ = /^(\d*\.?\d*)t$/;
/**
* @const
* @private {!RegExp}
* @example 3.45h, 3m or 4.20s
*/
shaka.text.TtmlTextParser.timeHMSFormat_ =
/^(?:(\d*\.?\d*)h)?(?:(\d*\.?\d*)m)?(?:(\d*\.?\d*)s)?(?:(\d*\.?\d*)ms)?$/;
/**
* @const
* @private {!RegExp}
* @example 50% 10%
*/
shaka.text.TtmlTextParser.percentValues_ = /^(\d{1,2}|100)% (\d{1,2}|100)%$/;
/**
* @const
* @private {!RegExp}
* @example 100px
*/
shaka.text.TtmlTextParser.unitValues_ = /^(\d+px|\d+em)$/;
/**
* @const
* @private {!Object}
*/
shaka.text.TtmlTextParser.textAlignToLineAlign_ = {
'left': 'start',
'center': 'center',
'right': 'end',
'start': 'start',
'end': 'end'
};
/**
* @const
* @private {!Object}
*/
shaka.text.TtmlTextParser.textAlignToPositionAlign_ = {
'left': 'line-left',
'center': 'center',
'right': 'line-right'
};
/**
* Gets leaf nodes of the xml node tree. Ignores the text, br elements
* and the spans positioned inside paragraphs
*
* @param {Element} element
* @return {!Array.<!Element>}
* @private
*/
shaka.text.TtmlTextParser.getLeafNodes_ = function(element) {
var result = [];
if (!element)
return result;
var childNodes = element.childNodes;
for (var i = 0; i < childNodes.length; i++) {
// Currently we don't support styles applicable to span
// elements, so they are ignored
var isSpanChildOfP = childNodes[i].nodeName == 'span' &&
element.nodeName == 'p';
if (childNodes[i].nodeType == Node.ELEMENT_NODE &&
childNodes[i].nodeName != 'br' && !isSpanChildOfP) {
// Get the leafs the child might contain
goog.asserts.assert(childNodes[i] instanceof Element,
'Node should be Element!');
var leafChildren = shaka.text.TtmlTextParser.getLeafNodes_(
/** @type {Element} */(childNodes[i]));
goog.asserts.assert(leafChildren.length > 0,
'Only a null Element should return no leaves!');
result = result.concat(leafChildren);
}
}
// if no result at this point, the element itself must be a leaf
if (!result.length) {
result.push(element);
}
return result;
};
/**
* Insert \n where <br> tags are found
*
* @param {!Node} element
* @param {boolean} whitespaceTrim
* @private
*/
shaka.text.TtmlTextParser.addNewLines_ = function(element, whitespaceTrim) {
var childNodes = element.childNodes;
for (var i = 0; i < childNodes.length; i++) {
if (childNodes[i].nodeName == 'br' && i > 0) {
childNodes[i - 1].textContent += '\n';
} else if (childNodes[i].childNodes.length > 0) {
shaka.text.TtmlTextParser.addNewLines_(childNodes[i], whitespaceTrim);
} else if (whitespaceTrim) {
// Trim leading and trailing whitespace.
var trimmed = childNodes[i].textContent.trim();
// Collapse multiple spaces into one.
trimmed = trimmed.replace(/\s+/g, ' ');
childNodes[i].textContent = trimmed;
}
}
};
/**
* Parses an Element into a TextTrackCue or VTTCue.
*
* @param {!Element} cueElement
* @param {number} offset
* @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
* @param {!Array.<!Element>} styles
* @param {!Array.<!Element>} regions
* @param {boolean} whitespaceTrim
* @return {shaka.text.Cue}
* @private
*/
shaka.text.TtmlTextParser.parseCue_ = function(
cueElement, offset, rateInfo, styles, regions, whitespaceTrim) {
// Disregard empty elements:
// TTML allows for empty elements like <div></div>.
// If cueElement has neither time attributes, nor
// non-whitespace text, don't try to make a cue out of it.
if (!cueElement.hasAttribute('begin') &&
!cueElement.hasAttribute('end') &&
/^\s*$/.test(cueElement.textContent))
return null;
shaka.text.TtmlTextParser.addNewLines_(cueElement, whitespaceTrim);
// Get time
var start = shaka.text.TtmlTextParser.parseTime_(
cueElement.getAttribute('begin'), rateInfo);
var end = shaka.text.TtmlTextParser.parseTime_(
cueElement.getAttribute('end'), rateInfo);
var duration = shaka.text.TtmlTextParser.parseTime_(
cueElement.getAttribute('dur'), rateInfo);
var payload = cueElement.textContent;
if (end == null && duration != null)
end = start + duration;
if (start == null || end == null) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.TEXT,
shaka.util.Error.Code.INVALID_TEXT_CUE);
}
start += offset;
end += offset;
var cue = new shaka.text.Cue(start, end, payload);
// Get other properties if available
var region = shaka.text.TtmlTextParser.getElementFromCollection_(
cueElement, 'region', regions);
shaka.text.TtmlTextParser.addStyle_(cue, cueElement, region, styles);
return cue;
};
/**
* Adds applicable style properties to a cue.
*
* @param {!shaka.text.Cue} cue
* @param {!Element} cueElement
* @param {Element} region
* @param {!Array.<!Element>} styles
* @private
*/
shaka.text.TtmlTextParser.addStyle_ = function(
cue, cueElement, region, styles) {
var TtmlTextParser = shaka.text.TtmlTextParser;
var Cue = shaka.text.Cue;
var results = null;
var extent = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:extent');
if (extent) {
results = TtmlTextParser.percentValues_.exec(extent);
if (results != null) {
// Use width value of the extent attribute for size.
// Height value is ignored.
cue.size = Number(results[1]);
}
}
var direction = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:direction');
if (direction == 'rtl')
cue.writingDirection = Cue.writingDirection.HORIZONTAL_RIGHT_TO_LEFT;
// Direction attribute specifies one-dimentional writing direction
// (left to right or right to left). Writing mode specifies that
// plus whether text is vertical or horizontal.
// They should not contradict each other. If they do, we give
// preference to writing mode.
var writingMode = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:writingMode');
if (writingMode == 'tb' || writingMode == 'tblr')
cue.writingDirection = Cue.writingDirection.VERTICAL_LEFT_TO_RIGHT;
else if (writingMode == 'tbrl')
cue.writingDirection = Cue.writingDirection.VERTICAL_RIGHT_TO_LEFT;
else if (writingMode == 'rltb' || writingMode == 'rl')
cue.writingDirection = Cue.writingDirection.HORIZONTAL_RIGHT_TO_LEFT;
else if (writingMode)
cue.writingDirection = Cue.writingDirection.HORIZONTAL_LEFT_TO_RIGHT;
var origin = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:origin');
if (origin) {
results = TtmlTextParser.percentValues_.exec(origin);
if (results != null) {
// for horizontal text use first coordinate of tts:origin
// to represent position of the cue and second - for line.
// Otherwise (vertical), use them the other way around.
if (cue.writingDirection ==
Cue.writingDirection.HORIZONTAL_LEFT_TO_RIGHT ||
cue.writingDirection ==
Cue.writingDirection.HORIZONTAL_RIGHT_TO_LEFT) {
cue.position = Number(results[1]);
cue.line = Number(results[2]);
} else {
cue.position = Number(results[2]);
cue.line = Number(results[1]);
}
cue.lineInterpretation = Cue.lineInterpretation.PERCENTAGE;
}
}
var align = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:textAlign');
if (align) {
cue.positionAlign = TtmlTextParser.textAlignToPositionAlign_[align];
cue.lineAlign = TtmlTextParser.textAlignToLineAlign_[align];
goog.asserts.assert(align.toUpperCase() in Cue.textAlign,
align.toUpperCase() +
' Should be in Cue.textAlign values!');
cue.textAlign = Cue.textAlign[align.toUpperCase()];
}
var displayAlign = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:displayAlign');
if (displayAlign) {
goog.asserts.assert(displayAlign.toUpperCase() in Cue.displayAlign,
displayAlign.toUpperCase() +
' Should be in Cue.displayAlign values!');
cue.displayAlign = Cue.displayAlign[displayAlign.toUpperCase()];
}
var color = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:color');
if (color)
cue.color = color;
var backgroundColor = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:backgroundColor');
if (backgroundColor)
cue.backgroundColor = backgroundColor;
var fontFamily = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:fontFamily');
if (fontFamily)
cue.fontFamily = fontFamily;
var fontWeight = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:fontWeight');
if (fontWeight && fontWeight == 'bold')
cue.fontWeight = Cue.fontWeight.BOLD;
var wrapOption = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:wrapOption');
if (wrapOption && wrapOption == 'noWrap')
cue.wrapLine = false;
var lineHeight = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:lineHeight');
if (lineHeight && lineHeight.match(TtmlTextParser.unitValues_))
cue.lineHeight = lineHeight;
var fontSize = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:fontSize');
if (fontSize && fontSize.match(TtmlTextParser.unitValues_))
cue.fontSize = fontSize;
var fontStyle = TtmlTextParser.getStyleAttribute_(
cueElement, region, styles, 'tts:fontStyle');
if (fontStyle) {
goog.asserts.assert(fontStyle.toUpperCase() in Cue.fontStyle,
fontStyle.toUpperCase() +
' Should be in Cue.fontStyle values!');
cue.fontStyle = Cue.fontStyle[fontStyle.toUpperCase()];
}
// Text decoration is an array of values which can come both
// from the element's style or be inherited from elements'
// parent nodes. All of those values should be applied as long
// as they don't contradict each other. If they do, elements'
// own style gets preference.
var textDecorationRegion = TtmlTextParser.getStyleAttributeFromRegion_(
region, styles, 'tts:textDecoration');
if (textDecorationRegion)
TtmlTextParser.addTextDecoration_(cue, textDecorationRegion);
var textDecorationElement = TtmlTextParser.getStyleAttributeFromElement_(
cueElement, styles, 'tts:textDecoration');
if (textDecorationElement)
TtmlTextParser.addTextDecoration_(cue, textDecorationElement);
};
/**
* Parses text decoration values and adds/removes them to/from the cue.
*
* @param {!shaka.text.Cue} cue
* @param {string} decoration
* @private
*/
shaka.text.TtmlTextParser.addTextDecoration_ = function(cue, decoration) {
var Cue = shaka.text.Cue;
var values = decoration.split(' ');
for (var i = 0; i < values.length; i++) {
switch (values[i]) {
case 'underline':
if (cue.textDecoration.indexOf(Cue.textDecoration.UNDERLINE) < 0)
cue.textDecoration.push(Cue.textDecoration.UNDERLINE);
break;
case 'noUnderline':
if (cue.textDecoration.indexOf(Cue.textDecoration.UNDERLINE) >= 0) {
shaka.util.ArrayUtils.remove(cue.textDecoration,
Cue.textDecoration.UNDERLINE);
}
break;
case 'lineThrough':
if (cue.textDecoration.indexOf(Cue.textDecoration.LINE_THROUGH) < 0)
cue.textDecoration.push(Cue.textDecoration.LINE_THROUGH);
break;
case 'noLineThrough':
if (cue.textDecoration.indexOf(Cue.textDecoration.LINE_THROUGH) >= 0) {
shaka.util.ArrayUtils.remove(cue.textDecoration,
Cue.textDecoration.LINE_THROUGH);
}
break;
case 'overline':
if (cue.textDecoration.indexOf(Cue.textDecoration.OVERLINE) < 0)
cue.textDecoration.push(Cue.textDecoration.OVERLINE);
break;
case 'noOverline':
if (cue.textDecoration.indexOf(Cue.textDecoration.OVERLINE) >= 0) {
shaka.util.ArrayUtils.remove(cue.textDecoration,
Cue.textDecoration.OVERLINE);
}
break;
}
}
};
/**
* Finds a specified attribute on either the original cue element or its
* associated region and returns the value if the attribute was found.
*
* @param {!Element} cueElement
* @param {Element} region
* @param {!Array.<!Element>} styles
* @param {string} attribute
* @return {?string}
* @private
*/
shaka.text.TtmlTextParser.getStyleAttribute_ = function(
cueElement, region, styles, attribute) {
// An attribute can be specified on region level or in a styling block
// associated with the region or original element.
var TtmlTextParser = shaka.text.TtmlTextParser;
var attr = TtmlTextParser.getStyleAttributeFromElement_(
cueElement, styles, attribute);
if (attr)
return attr;
return TtmlTextParser.getStyleAttributeFromRegion_(
region, styles, attribute);
};
/**
* Finds a specified attribute on the element's associated region
* and returns the value if the attribute was found.
*
* @param {Element} region
* @param {!Array.<!Element>} styles
* @param {string} attribute
* @return {?string}
* @private
*/
shaka.text.TtmlTextParser.getStyleAttributeFromRegion_ = function(
region, styles, attribute) {
var regionChildren = shaka.text.TtmlTextParser.getLeafNodes_(region);
for (var i = 0; i < regionChildren.length; i++) {
var attr = regionChildren[i].getAttribute(attribute);
if (attr)
return attr;
}
var style = shaka.text.TtmlTextParser.getElementFromCollection_(
region, 'style', styles);
if (style)
return style.getAttribute(attribute);
return null;
};
/**
* Finds a specified attribute on the cue element and returns the value
* if the attribute was found.
*
* @param {!Element} cueElement
* @param {!Array.<!Element>} styles
* @param {string} attribute
* @return {?string}
* @private
*/
shaka.text.TtmlTextParser.getStyleAttributeFromElement_ = function(
cueElement, styles, attribute) {
var getElementFromCollection_ =
shaka.text.TtmlTextParser.getElementFromCollection_;
var style = getElementFromCollection_(cueElement, 'style', styles);
if (style)
return style.getAttribute(attribute);
return null;
};
/**
* Selects an item from |collection| whose id matches |attributeName|
* from |element|.
*
* @param {Element} element
* @param {string} attributeName
* @param {!Array.<Element>} collection
* @return {Element}
* @private
*/
shaka.text.TtmlTextParser.getElementFromCollection_ = function(
element, attributeName, collection) {
if (!element || collection.length < 1) {
return null;
}
var item = null;
var itemName = shaka.text.TtmlTextParser.getInheritedAttribute_(
element, attributeName);
if (itemName) {
for (var i = 0; i < collection.length; i++) {
if (collection[i].getAttribute('xml:id') == itemName) {
item = collection[i];
break;
}
}
}
return item;
};
/**
* Traverses upwards from a given node until a given attribute is found.
*
* @param {!Element} element
* @param {string} attributeName
* @return {?string}
* @private
*/
shaka.text.TtmlTextParser.getInheritedAttribute_ = function(
element, attributeName) {
var ret = null;
while (element) {
ret = element.getAttribute(attributeName);
if (ret) {
break;
}
// Element.parentNode can lead to XMLDocument, which is not an Element and
// has no getAttribute().
var parentNode = element.parentNode;
if (parentNode instanceof Element) {
element = parentNode;
} else {
break;
}
}
return ret;
};
/**
* Parses a TTML time from the given word.
*
* @param {string} text
* @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
* @return {?number}
* @private
*/
shaka.text.TtmlTextParser.parseTime_ = function(text, rateInfo) {
var ret = null;
var TtmlTextParser = shaka.text.TtmlTextParser;
if (TtmlTextParser.timeColonFormatFrames_.test(text)) {
ret = TtmlTextParser.parseColonTimeWithFrames_(rateInfo, text);
} else if (TtmlTextParser.timeColonFormat_.test(text)) {
ret = TtmlTextParser.parseTimeFromRegex_(
TtmlTextParser.timeColonFormat_, text);
} else if (TtmlTextParser.timeColonFormatMilliseconds_.test(text)) {
ret = TtmlTextParser.parseTimeFromRegex_(
TtmlTextParser.timeColonFormatMilliseconds_, text);
} else if (TtmlTextParser.timeFramesFormat_.test(text)) {
ret = TtmlTextParser.parseFramesTime_(rateInfo, text);
} else if (TtmlTextParser.timeTickFormat_.test(text)) {
ret = TtmlTextParser.parseTickTime_(rateInfo, text);
} else if (TtmlTextParser.timeHMSFormat_.test(text)) {
ret = TtmlTextParser.parseTimeFromRegex_(
TtmlTextParser.timeHMSFormat_, text);
}
return ret;
};
/**
* Parses a TTML time in frame format
*
* @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
* @param {string} text
* @return {?number}
* @private
*/
shaka.text.TtmlTextParser.parseFramesTime_ = function(rateInfo, text) {
// 75f or 75.5f
var results = shaka.text.TtmlTextParser.timeFramesFormat_.exec(text);
var frames = Number(results[1]);
return frames / rateInfo.frameRate;
};
/**
* Parses a TTML time in tick format
*
* @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
* @param {string} text
* @return {?number}
* @private
*/
shaka.text.TtmlTextParser.parseTickTime_ = function(rateInfo, text) {
// 50t or 50.5t
var results = shaka.text.TtmlTextParser.timeTickFormat_.exec(text);
var ticks = Number(results[1]);
return ticks / rateInfo.tickRate;
};
/**
* Parses a TTML colon formatted time containing frames
*
* @param {!shaka.text.TtmlTextParser.RateInfo_} rateInfo
* @param {string} text
* @return {?number}
* @private
*/
shaka.text.TtmlTextParser.parseColonTimeWithFrames_ = function(
rateInfo, text) {
// 01:02:43:07 ('07' is frames) or 01:02:43:07.1 (subframes)
var results = shaka.text.TtmlTextParser.timeColonFormatFrames_.exec(text);
var hours = Number(results[1]);
var minutes = Number(results[2]);
var seconds = Number(results[3]);
var frames = Number(results[4]);
var subframes = Number(results[5]) || 0;
frames += subframes / rateInfo.subFrameRate;
seconds += frames / rateInfo.frameRate;
return seconds + (minutes * 60) + (hours * 3600);
};
/**
* Parses a TTML time with a given regex. Expects regex to be some
* sort of a time-matcher to match hours, minutes, seconds and milliseconds
*
* @param {!RegExp} regex
* @param {string} text
* @return {?number}
* @private
*/
shaka.text.TtmlTextParser.parseTimeFromRegex_ = function(regex, text) {
var results = regex.exec(text);
if (results == null || results[0] == '')
return null;
// This capture is optional, but will still be in the array as undefined,
// default to 0.
var hours = Number(results[1]) || 0;
var minutes = Number(results[2]) || 0;
var seconds = Number(results[3]) || 0;
var miliseconds = Number(results[4]) || 0;
return (miliseconds / 1000) + seconds + (minutes * 60) + (hours * 3600);
};
/**
* Contains information about frame/subframe rate
* and frame rate multiplier for time in frame format.
* ex. 01:02:03:04(4 frames) or 01:02:03:04.1(4 frames, 1 subframe)
*
* @param {?string} frameRate
* @param {?string} subFrameRate
* @param {?string} frameRateMultiplier
* @param {?string} tickRate
* @constructor
* @struct
* @private
*/
shaka.text.TtmlTextParser.RateInfo_ = function(
frameRate, subFrameRate, frameRateMultiplier, tickRate) {
/**
* @type {number}
*/
this.frameRate = Number(frameRate) || 30;
/**
* @type {number}
*/
this.subFrameRate = Number(subFrameRate) || 1;
/**
* @type {number}
*/
this.tickRate = Number(tickRate);
if (this.tickRate == 0) {
if (frameRate)
this.tickRate = this.frameRate * this.subFrameRate;
else
this.tickRate = 1;
}
if (frameRateMultiplier) {
var multiplierResults = /^(\d+) (\d+)$/g.exec(frameRateMultiplier);
if (multiplierResults) {
var numerator = multiplierResults[1];
var denominator = multiplierResults[2];
var multiplierNum = numerator / denominator;
this.frameRate *= multiplierNum;
}
}
};
shaka.text.TextEngine.registerParser(
'application/ttml+xml',
shaka.text.TtmlTextParser);