Source: lib/util/platform.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.util.Platform');
  9. goog.require('shaka.drm.DrmUtils');
  10. goog.require('shaka.log');
  11. goog.require('shaka.util.Timer');
  14. /**
  15.  * A wrapper for platform-specific functions.
  16.  *
  17.  * @final
  18.  */
  19. shaka.util.Platform = class {
  20.   /**
  21.    * Check if the current platform supports media source. We assume that if
  22.    * the current platform supports media source, then we can use media source
  23.    * as per its design.
  24.    *
  25.    * @return {boolean}
  26.    */
  27.   static supportsMediaSource() {
  28.     const mediaSource = window.ManagedMediaSource || window.MediaSource;
  29.     // Browsers that lack a media source implementation will have no reference
  30.     // to |window.MediaSource|. Platforms that we see having problematic media
  31.     // source implementations will have this reference removed via a polyfill.
  32.     if (!mediaSource) {
  33.       return false;
  34.     }
  36.     // Some very old MediaSource implementations didn't have isTypeSupported.
  37.     if (!mediaSource.isTypeSupported) {
  38.       return false;
  39.     }
  41.     return true;
  42.   }
  44.   /**
  45.    * Returns true if the media type is supported natively by the platform.
  46.    *
  47.    * @param {string} mimeType
  48.    * @return {boolean}
  49.    */
  50.   static supportsMediaType(mimeType) {
  51.     const video = shaka.util.Platform.anyMediaElement();
  52.     return video.canPlayType(mimeType) != '';
  53.   }
  55.   /**
  56.    * Check if the current platform is MS Edge.
  57.    *
  58.    * @return {boolean}
  59.    */
  60.   static isEdge() {
  61.     // Legacy Edge contains "Edge/version".
  62.     // Chromium-based Edge contains "Edg/version" (no "e").
  63.     if (navigator.userAgent.match(/Edge?\//)) {
  64.       return true;
  65.     }
  67.     return false;
  68.   }
  70.   /**
  71.    * Check if the current platform is Legacy Edge.
  72.    *
  73.    * @return {boolean}
  74.    */
  75.   static isLegacyEdge() {
  76.     // Legacy Edge contains "Edge/version".
  77.     // Chromium-based Edge contains "Edg/version" (no "e").
  78.     if (navigator.userAgent.match(/Edge\//)) {
  79.       return true;
  80.     }
  82.     return false;
  83.   }
  85.   /**
  86.    * Check if the current platform is MS IE.
  87.    *
  88.    * @return {boolean}
  89.    */
  90.   static isIE() {
  91.     return shaka.util.Platform.userAgentContains_('Trident/');
  92.   }
  94.   /**
  95.    * Check if the current platform is an Xbox One.
  96.    *
  97.    * @return {boolean}
  98.    */
  99.   static isXboxOne() {
  100.     return shaka.util.Platform.userAgentContains_('Xbox One');
  101.   }
  103.   /**
  104.    * Check if the current platform is a Tizen TV.
  105.    *
  106.    * @return {boolean}
  107.    */
  108.   static isTizen() {
  109.     return shaka.util.Platform.userAgentContains_('Tizen');
  110.   }
  112.   /**
  113.    * Check if the current platform is a Tizen 6 TV.
  114.    *
  115.    * @return {boolean}
  116.    */
  117.   static isTizen6() {
  118.     return shaka.util.Platform.userAgentContains_('Tizen 6');
  119.   }
  121.   /**
  122.    * Check if the current platform is a Tizen 5.0 TV.
  123.    *
  124.    * @return {boolean}
  125.    */
  126.   static isTizen5_0() {
  127.     return shaka.util.Platform.userAgentContains_('Tizen 5.0');
  128.   }
  130.   /**
  131.    * Check if the current platform is a Tizen 5 TV.
  132.    *
  133.    * @return {boolean}
  134.    */
  135.   static isTizen5() {
  136.     return shaka.util.Platform.userAgentContains_('Tizen 5');
  137.   }
  139.   /**
  140.    * Check if the current platform is a Tizen 4 TV.
  141.    *
  142.    * @return {boolean}
  143.    */
  144.   static isTizen4() {
  145.     return shaka.util.Platform.userAgentContains_('Tizen 4');
  146.   }
  148.   /**
  149.    * Check if the current platform is a Tizen 3 TV.
  150.    *
  151.    * @return {boolean}
  152.    */
  153.   static isTizen3() {
  154.     return shaka.util.Platform.userAgentContains_('Tizen 3');
  155.   }
  157.   /**
  158.    * Check if the current platform is a Tizen 2 TV.
  159.    *
  160.    * @return {boolean}
  161.    */
  162.   static isTizen2() {
  163.     return shaka.util.Platform.userAgentContains_('Tizen 2');
  164.   }
  166.   /**
  167.    * Check if the current platform is a WebOS.
  168.    *
  169.    * @return {boolean}
  170.    */
  171.   static isWebOS() {
  172.     return shaka.util.Platform.userAgentContains_('Web0S');
  173.   }
  175.   /**
  176.    * Check if the current platform is a WebOS 3.
  177.    *
  178.    * @return {boolean}
  179.    */
  180.   static isWebOS3() {
  181.     // See: https://webostv.developer.lge.com/develop/specifications/web-api-and-web-engine#useragent-string
  182.     return shaka.util.Platform.isWebOS() &&
  183.         shaka.util.Platform.chromeVersion() === 38;
  184.   }
  186.   /**
  187.    * Check if the current platform is a WebOS 4.
  188.    *
  189.    * @return {boolean}
  190.    */
  191.   static isWebOS4() {
  192.     // See: https://webostv.developer.lge.com/develop/specifications/web-api-and-web-engine#useragent-string
  193.     return shaka.util.Platform.isWebOS() &&
  194.         shaka.util.Platform.chromeVersion() === 53;
  195.   }
  197.   /**
  198.    * Check if the current platform is a WebOS 5.
  199.    *
  200.    * @return {boolean}
  201.    */
  202.   static isWebOS5() {
  203.     // See: https://webostv.developer.lge.com/develop/specifications/web-api-and-web-engine#useragent-string
  204.     return shaka.util.Platform.isWebOS() &&
  205.         shaka.util.Platform.chromeVersion() === 68;
  206.   }
  208.   /**
  209.    * Check if the current platform is a WebOS 6.
  210.    *
  211.    * @return {boolean}
  212.    */
  213.   static isWebOS6() {
  214.     // See: https://webostv.developer.lge.com/develop/specifications/web-api-and-web-engine#useragent-string
  215.     return shaka.util.Platform.isWebOS() &&
  216.         shaka.util.Platform.chromeVersion() === 79;
  217.   }
  219.   /**
  220.    * Check if the current platform is a Google Chromecast.
  221.    *
  222.    * @return {boolean}
  223.    */
  224.   static isChromecast() {
  225.     return shaka.util.Platform.userAgentContains_('CrKey');
  226.   }
  228.   /**
  229.    * Check if the current platform is a Google Chromecast without
  230.    * Android or Fuchsia.
  231.    *
  232.    * @return {boolean}
  233.    */
  234.   static isOlderChromecast() {
  235.     const Platform = shaka.util.Platform;
  236.     return Platform.isChromecast() &&
  237.         !Platform.isAndroid() && !Platform.isFuchsia();
  238.   }
  240.   /**
  241.    * Check if the current platform is a Google Chromecast with Android
  242.    * (i.e. Chromecast with GoogleTV).
  243.    *
  244.    * @return {boolean}
  245.    */
  246.   static isAndroidCastDevice() {
  247.     const Platform = shaka.util.Platform;
  248.     return Platform.isChromecast() && Platform.isAndroid();
  249.   }
  251.   /**
  252.    * Check if the current platform is a Google Chromecast with Fuchsia
  253.    * (i.e. Google Nest Hub).
  254.    *
  255.    * @return {boolean}
  256.    */
  257.   static isFuchsiaCastDevice() {
  258.     const Platform = shaka.util.Platform;
  259.     return Platform.isChromecast() && Platform.isFuchsia();
  260.   }
  262.   /**
  263.    * Returns a major version number for Chrome, or Chromium-based browsers.
  264.    *
  265.    * For example:
  266.    *   - Chrome 106.0.5249.61 returns 106.
  267.    *   - Edge 106.0.1370.34 returns 106 (since this is based on Chromium).
  268.    *   - Safari returns null (since this is independent of Chromium).
  269.    *
  270.    * @return {?number} A major version number or null if not Chromium-based.
  271.    */
  272.   static chromeVersion() {
  273.     if (!shaka.util.Platform.isChrome()) {
  274.       return null;
  275.     }
  277.     // Looking for something like "Chrome/106.0.0.0".
  278.     const match = navigator.userAgent.match(/Chrome\/(\d+)/);
  279.     if (match) {
  280.       return parseInt(match[1], /* base= */ 10);
  281.     }
  283.     return null;
  284.   }
  286.   /**
  287.    * Check if the current platform is Google Chrome.
  288.    *
  289.    * @return {boolean}
  290.    */
  291.   static isChrome() {
  292.     // The Edge Legacy user agent will also contain the "Chrome" keyword, so we
  293.     // need to make sure this is not Edge Legacy.
  294.     return shaka.util.Platform.userAgentContains_('Chrome') &&
  295.            !shaka.util.Platform.isLegacyEdge();
  296.   }
  298.   /**
  299.    * Check if the current platform is Firefox.
  300.    *
  301.    * @return {boolean}
  302.    */
  303.   static isFirefox() {
  304.     return shaka.util.Platform.userAgentContains_('Firefox');
  305.   }
  307.   /**
  308.    * Check if the current platform is from Apple.
  309.    *
  310.    * Returns true on all iOS browsers and on desktop Safari.
  311.    *
  312.    * Returns false for non-Safari browsers on macOS, which are independent of
  313.    * Apple.
  314.    *
  315.    * @return {boolean}
  316.    */
  317.   static isApple() {
  318.     return shaka.util.Platform.isAppleVendor_() &&
  319.         (shaka.util.Platform.isMac() || shaka.util.Platform.isIOS());
  320.   }
  322.   /**
  323.    * Check if the current platform is Playstation 5.
  324.    *
  325.    * Returns true on Playstation 5 browsers.
  326.    *
  327.    * Returns false for Playstation 5 browsers
  328.    *
  329.    * @return {boolean}
  330.    */
  331.   static isPS5() {
  332.     return shaka.util.Platform.userAgentContains_('PlayStation 5');
  333.   }
  335.   /**
  336.    * Check if the current platform is Playstation 4.
  337.    * @return {boolean}
  338.    */
  339.   static isPS4() {
  340.     return shaka.util.Platform.userAgentContains_('PlayStation 4');
  341.   }
  343.   /**
  344.    * Check if the current platform is Hisense.
  345.    * @return {boolean}
  346.    */
  347.   static isHisense() {
  348.     return shaka.util.Platform.userAgentContains_('Hisense') ||
  349.         shaka.util.Platform.userAgentContains_('VIDAA');
  350.   }
  352.   /**
  353.    * Check if the current platform is Orange.
  354.    * @return {boolean}
  355.    */
  356.   static isOrange() {
  357.     return shaka.util.Platform.userAgentContains_('SOPOpenBrowser');
  358.   }
  360.   /**
  361.    * Check if the current platform is SkyQ STB.
  362.    * @return {boolean}
  363.    */
  364.   static isSkyQ() {
  365.     return shaka.util.Platform.userAgentContains_('Sky_STB');
  366.   }
  368.   /**
  369.    * Check if the current platform is Deutsche Telecom Zenterio STB.
  370.    * @return {boolean}
  371.    */
  372.   static isZenterio() {
  373.     return shaka.util.Platform.userAgentContains_('DT_STB_BCM');
  374.   }
  376.   /**
  377.    * Returns a major version number for Safari, or Webkit-based STBs,
  378.    * or Safari-based iOS browsers.
  379.    *
  380.    * For example:
  381.    *   - Safari 13.0.4 on macOS returns 13.
  382.    *   - Safari on iOS 13.3.1 returns 13.
  383.    *   - Chrome on iOS 13.3.1 returns 13 (since this is based on Safari/WebKit).
  384.    *   - Chrome on macOS returns null (since this is independent of Apple).
  385.    *
  386.    * Returns null on Firefox on iOS, where this version information is not
  387.    * available.
  388.    *
  389.    * @return {?number} A major version number or null if not iOS.
  390.    */
  391.   static safariVersion() {
  392.     // All iOS browsers and desktop Safari will return true for isApple().
  393.     if (!shaka.util.Platform.isApple() && !shaka.util.Platform.isWebkitSTB()) {
  394.       return null;
  395.     }
  397.     // This works for iOS Safari and desktop Safari, which contain something
  398.     // like "Version/13.0" indicating the major Safari or iOS version.
  399.     let match = navigator.userAgent.match(/Version\/(\d+)/);
  400.     if (match) {
  401.       return parseInt(match[1], /* base= */ 10);
  402.     }
  404.     // This works for all other browsers on iOS, which contain something like
  405.     // "OS 13_3" indicating the major & minor iOS version.
  406.     match = navigator.userAgent.match(/OS (\d+)(?:_\d+)?/);
  407.     if (match) {
  408.       return parseInt(match[1], /* base= */ 10);
  409.     }
  411.     return null;
  412.   }
  414.   /**
  415.    * Guesses if the platform is an Apple mobile one (iOS, iPad, iPod).
  416.    * @return {boolean}
  417.    */
  418.   static isIOS() {
  419.     if (/(?:iPhone|iPad|iPod)/.test(navigator.userAgent)) {
  420.       // This is Android, iOS, or iPad < 13.
  421.       return true;
  422.     }
  424.     // Starting with iOS 13 on iPad, the user agent string no longer has the
  425.     // word "iPad" in it.  It looks very similar to desktop Safari.  This seems
  426.     // to be intentional on Apple's part.
  427.     // See: https://forums.developer.apple.com/thread/119186
  428.     //
  429.     // So if it's an Apple device with multi-touch support, assume it's a mobile
  430.     // device.  If some future iOS version starts masking their user agent on
  431.     // both iPhone & iPad, this clause should still work.  If a future
  432.     // multi-touch desktop Mac is released, this will need some adjustment.
  433.     //
  434.     // As of January 2020, this is mainly used to adjust the default UI config
  435.     // for mobile devices, so it's low risk if something changes to break this
  436.     // detection.
  437.     return shaka.util.Platform.isAppleVendor_() && navigator.maxTouchPoints > 1;
  438.   }
  440.   /**
  441.    * Guesses if the platform is a mobile one.
  442.    * @return {boolean}
  443.    */
  444.   static isMobile() {
  445.     if (navigator.userAgentData) {
  446.       return navigator.userAgentData.mobile;
  447.     }
  448.     return shaka.util.Platform.isIOS() || shaka.util.Platform.isAndroid();
  449.   }
  451.   /**
  452.    * Return true if the platform is a Mac, regardless of the browser.
  453.    *
  454.    * @return {boolean}
  455.    */
  456.   static isMac() {
  457.     // Try the newer standard first.
  458.     if (navigator.userAgentData && navigator.userAgentData.platform) {
  459.       return navigator.userAgentData.platform.toLowerCase() == 'macos';
  460.     }
  461.     // Fall back to the old API, with less strict matching.
  462.     if (!navigator.platform) {
  463.       return false;
  464.     }
  465.     return navigator.platform.toLowerCase().includes('mac');
  466.   }
  468.   /**
  469.    * Return true if the platform is a VisionOS.
  470.    *
  471.    * @return {boolean}
  472.    */
  473.   static isVisionOS() {
  474.     if (!shaka.util.Platform.isMac()) {
  475.       return false;
  476.     }
  477.     if (!('xr' in navigator)) {
  478.       return false;
  479.     }
  480.     return true;
  481.   }
  483.   /**
  484.    * Checks is non-Apple STB based on Webkit.
  485.    * @return {boolean}
  486.    */
  487.   static isWebkitSTB() {
  488.     return shaka.util.Platform.isAppleVendor_() &&
  489.         !shaka.util.Platform.isApple();
  490.   }
  492.   /**
  493.    * Return true if the platform is a Windows, regardless of the browser.
  494.    *
  495.    * @return {boolean}
  496.    */
  497.   static isWindows() {
  498.     // Try the newer standard first.
  499.     if (navigator.userAgentData && navigator.userAgentData.platform) {
  500.       return navigator.userAgentData.platform.toLowerCase() == 'windows';
  501.     }
  502.     // Fall back to the old API, with less strict matching.
  503.     if (!navigator.platform) {
  504.       return false;
  505.     }
  506.     return navigator.platform.toLowerCase().includes('win32');
  507.   }
  509.   /**
  510.    * Return true if the platform is a Android, regardless of the browser.
  511.    *
  512.    * @return {boolean}
  513.    */
  514.   static isAndroid() {
  515.     if (navigator.userAgentData && navigator.userAgentData.platform) {
  516.       return navigator.userAgentData.platform.toLowerCase() == 'android';
  517.     }
  518.     return shaka.util.Platform.userAgentContains_('Android');
  519.   }
  521.   /**
  522.    * Return true if the platform is a Fuchsia, regardless of the browser.
  523.    *
  524.    * @return {boolean}
  525.    */
  526.   static isFuchsia() {
  527.     if (navigator.userAgentData && navigator.userAgentData.platform) {
  528.       return navigator.userAgentData.platform.toLowerCase() == 'fuchsia';
  529.     }
  530.     return shaka.util.Platform.userAgentContains_('Fuchsia');
  531.   }
  533.   /**
  534.    * Return true if the platform is controlled by a remote control.
  535.    *
  536.    * @return {boolean}
  537.    */
  538.   static isSmartTV() {
  539.     const Platform = shaka.util.Platform;
  540.     if (Platform.isTizen() || Platform.isWebOS() ||
  541.         Platform.isXboxOne() || Platform.isPS4() ||
  542.         Platform.isPS5() || Platform.isChromecast() ||
  543.         Platform.isHisense() || Platform.isWebkitSTB()) {
  544.       return true;
  545.     }
  546.     return false;
  547.   }
  549.   /**
  550.    * Check if the user agent contains a key. This is the best way we know of
  551.    * right now to detect platforms. If there is a better way, please send a
  552.    * PR.
  553.    *
  554.    * @param {string} key
  555.    * @return {boolean}
  556.    * @private
  557.    */
  558.   static userAgentContains_(key) {
  559.     const userAgent = navigator.userAgent || '';
  560.     return userAgent.includes(key);
  561.   }
  563.   /**
  564.    * @return {boolean}
  565.    * @private
  566.    */
  567.   static isAppleVendor_() {
  568.     return (navigator.vendor || '').includes('Apple');
  569.   }
  571.   /**
  572.    * For canPlayType queries, we just need any instance.
  573.    *
  574.    * First, use a cached element from a previous query.
  575.    * Second, search the page for one.
  576.    * Third, create a temporary one.
  577.    *
  578.    * Cached elements expire in one second so that they can be GC'd or removed.
  579.    *
  580.    * @return {!HTMLMediaElement}
  581.    */
  582.   static anyMediaElement() {
  583.     const Platform = shaka.util.Platform;
  584.     if (Platform.cachedMediaElement_) {
  585.       return Platform.cachedMediaElement_;
  586.     }
  588.     if (!Platform.cacheExpirationTimer_) {
  589.       Platform.cacheExpirationTimer_ = new shaka.util.Timer(() => {
  590.         Platform.cachedMediaElement_ = null;
  591.       });
  592.     }
  594.     Platform.cachedMediaElement_ = /** @type {HTMLMediaElement} */(
  595.       document.getElementsByTagName('video')[0] ||
  596.       document.getElementsByTagName('audio')[0]);
  598.     if (!Platform.cachedMediaElement_) {
  599.       Platform.cachedMediaElement_ = /** @type {!HTMLMediaElement} */(
  600.         document.createElement('video'));
  601.     }
  603.     Platform.cacheExpirationTimer_.tickAfter(/* seconds= */ 1);
  604.     return Platform.cachedMediaElement_;
  605.   }
  607.   /**
  608.    * Returns true if the platform requires encryption information in all init
  609.    * segments.  For such platforms, MediaSourceEngine will attempt to work
  610.    * around a lack of such info by inserting fake encryption information into
  611.    * initialization segments.
  612.    *
  613.    * @param {?string} keySystem
  614.    * @return {boolean}
  615.    * @see https://github.com/shaka-project/shaka-player/issues/2759
  616.    */
  617.   static requiresEncryptionInfoInAllInitSegments(keySystem) {
  618.     const Platform = shaka.util.Platform;
  619.     const isPlayReady = shaka.drm.DrmUtils.isPlayReadyKeySystem(keySystem);
  620.     return Platform.isTizen() || Platform.isXboxOne() || Platform.isOrange() ||
  621.       (Platform.isEdge() && Platform.isWindows() && isPlayReady);
  622.   }
  624.   /**
  625.    * Returns true if the platform requires AC-3 signalling in init
  626.    * segments to be replaced with EC-3 signalling.
  627.    * For such platforms, MediaSourceEngine will attempt to work
  628.    * around it by inserting fake EC-3 signalling into
  629.    * initialization segments.
  630.    *
  631.    * @return {boolean}
  632.    */
  633.   static requiresEC3InitSegments() {
  634.     return shaka.util.Platform.isTizen3();
  635.   }
  637.   /**
  638.    * Returns true if the platform supports SourceBuffer "sequence mode".
  639.    *
  640.    * @return {boolean}
  641.    */
  642.   static supportsSequenceMode() {
  643.     const Platform = shaka.util.Platform;
  644.     if (Platform.isTizen3() || Platform.isTizen2() ||
  645.         Platform.isWebOS3() || Platform.isPS4() || Platform.isPS5()) {
  646.       return false;
  647.     }
  648.     return true;
  649.   }
  651.   /**
  652.    * Returns if codec switching SMOOTH is known reliable device support.
  653.    *
  654.    * Some devices are known not to support <code>SourceBuffer.changeType</code>
  655.    * well. These devices should use the reload strategy. If a device
  656.    * reports that it supports <code<changeType</code> but supports it unreliably
  657.    * it should be disallowed in this method.
  658.    *
  659.    * @return {boolean}
  660.    */
  661.   static supportsSmoothCodecSwitching() {
  662.     const Platform = shaka.util.Platform;
  663.     // All Tizen versions (up to Tizen 8) do not support SMOOTH so far.
  664.     // webOS seems to support SMOOTH from webOS 22.
  665.     if (Platform.isTizen() || Platform.isPS4() || Platform.isPS5() ||
  666.         Platform.isWebOS6()) {
  667.       return false;
  668.     }
  669.     // Older chromecasts without GoogleTV seem to not support SMOOTH properly.
  670.     if (Platform.isOlderChromecast()) {
  671.       return false;
  672.     }
  673.     // See: https://chromium-review.googlesource.com/c/chromium/src/+/4577759
  674.     if (Platform.isWindows() && Platform.isEdge()) {
  675.       return false;
  676.     }
  677.     return true;
  678.   }
  680.   /**
  681.    * On some platforms, such as v1 Chromecasts, the act of seeking can take a
  682.    * significant amount of time.
  683.    *
  684.    * @return {boolean}
  685.    */
  686.   static isSeekingSlow() {
  687.     const Platform = shaka.util.Platform;
  688.     if (Platform.isChromecast()) {
  689.       if (Platform.isAndroidCastDevice()) {
  690.         // Android-based Chromecasts are new enough to not be a problem.
  691.         return false;
  692.       } else {
  693.         return true;
  694.       }
  695.     }
  696.     return false;
  697.   }
  699.   /**
  700.    * Returns true if MediaKeys is polyfilled by the specified polyfill.
  701.    *
  702.    * @param {string} polyfillType
  703.    * @return {boolean}
  704.    */
  705.   static isMediaKeysPolyfilled(polyfillType) {
  706.     return polyfillType === window.shakaMediaKeysPolyfill;
  707.   }
  710.   /**
  711.    * Detect the maximum resolution that the platform's hardware can handle.
  712.    *
  713.    * @return {!Promise<shaka.extern.Resolution>}
  714.    */
  715.   static async detectMaxHardwareResolution() {
  716.     const Platform = shaka.util.Platform;
  718.     /** @type {shaka.extern.Resolution} */
  719.     const maxResolution = {
  720.       width: Infinity,
  721.       height: Infinity,
  722.     };
  724.     if (Platform.isChromecast()) {
  725.       // In our tests, the original Chromecast seems to have trouble decoding
  726.       // above 1080p. It would be a waste to select a higher res anyway, given
  727.       // that the device only outputs 1080p to begin with.
  728.       // Chromecast has an extension to query the device/display's resolution.
  729.       const hasCanDisplayType = window.cast && cast.__platform__ &&
  730.           cast.__platform__.canDisplayType;
  732.       // Some hub devices can only do 720p. Default to that.
  733.       maxResolution.width = 1280;
  734.       maxResolution.height = 720;
  736.       try {
  737.         if (hasCanDisplayType && await cast.__platform__.canDisplayType(
  738.             'video/mp4; codecs="avc1.640028"; width=3840; height=2160')) {
  739.           // The device and display can both do 4k. Assume a 4k limit.
  740.           maxResolution.width = 3840;
  741.           maxResolution.height = 2160;
  742.         } else if (hasCanDisplayType && await cast.__platform__.canDisplayType(
  743.             'video/mp4; codecs="avc1.640028"; width=1920; height=1080')) {
  744.           // Most Chromecasts can do 1080p.
  745.           maxResolution.width = 1920;
  746.           maxResolution.height = 1080;
  747.         }
  748.       } catch (error) {
  749.         // This shouldn't generally happen. Log the error.
  750.         shaka.log.alwaysError('Failed to check canDisplayType:', error);
  751.         // Now ignore the error and let the 720p default stand.
  752.       }
  753.     } else if (Platform.isTizen()) {
  754.       maxResolution.width = 1920;
  755.       maxResolution.height = 1080;
  756.       try {
  757.         if (webapis.systeminfo && webapis.systeminfo.getMaxVideoResolution) {
  758.           const maxVideoResolution =
  759.               webapis.systeminfo.getMaxVideoResolution();
  760.           maxResolution.width = maxVideoResolution.width;
  761.           maxResolution.height = maxVideoResolution.height;
  762.         } else {
  763.           if (webapis.productinfo.is8KPanelSupported &&
  764.               webapis.productinfo.is8KPanelSupported()) {
  765.             maxResolution.width = 7680;
  766.             maxResolution.height = 4320;
  767.           } else if (webapis.productinfo.isUdPanelSupported &&
  768.               webapis.productinfo.isUdPanelSupported()) {
  769.             maxResolution.width = 3840;
  770.             maxResolution.height = 2160;
  771.           }
  772.         }
  773.       } catch (e) {
  774.         shaka.log.alwaysWarn('Tizen: Error detecting screen size, default ' +
  775.             'screen size 1920x1080.');
  776.       }
  777.     } else if (Platform.isWebOS()) {
  778.       try {
  779.         const deviceInfo =
  780.         /** @type {{screenWidth: number, screenHeight: number}} */(
  781.             JSON.parse(window.PalmSystem.deviceInfo));
  782.         // WebOS has always been able to do 1080p.  Assume a 1080p limit.
  783.         maxResolution.width = Math.max(1920, deviceInfo['screenWidth']);
  784.         maxResolution.height = Math.max(1080, deviceInfo['screenHeight']);
  785.       } catch (e) {
  786.         shaka.log.alwaysWarn('WebOS: Error detecting screen size, default ' +
  787.             'screen size 1920x1080.');
  788.         maxResolution.width = 1920;
  789.         maxResolution.height = 1080;
  790.       }
  791.     } else if (Platform.isHisense()) {
  792.       let supports4k = null;
  793.       if (window.Hisense_Get4KSupportState) {
  794.         try {
  795.           // eslint-disable-next-line new-cap
  796.           supports4k = window.Hisense_Get4KSupportState();
  797.         } catch (e) {
  798.           shaka.log.debug('Hisense: Failed to get 4K support state', e);
  799.         }
  800.       }
  801.       if (supports4k == null) {
  802.         // If API is not there or not working for whatever reason, fallback to
  803.         // user agent check, as it contains UHD or FHD info.
  804.         supports4k = Platform.userAgentContains_('UHD');
  805.       }
  806.       if (supports4k) {
  807.         maxResolution.width = 3840;
  808.         maxResolution.height = 2160;
  809.       } else {
  810.         maxResolution.width = 1920;
  811.         maxResolution.height = 1080;
  812.       }
  813.     } else if (Platform.isPS4() || Platform.isPS5()) {
  814.       let supports4K = false;
  815.       try {
  816.         const result = await window.msdk.device.getDisplayInfo();
  817.         supports4K = result.resolution === '4K';
  818.       } catch (e) {
  819.         try {
  820.           const result = await window.msdk.device.getDisplayInfoImmediate();
  821.           supports4K = result.resolution === '4K';
  822.         } catch (e) {
  823.           shaka.log.alwaysWarn(
  824.               'PlayStation: Failed to get the display info:', e);
  825.         }
  826.       }
  827.       if (supports4K) {
  828.         maxResolution.width = 3840;
  829.         maxResolution.height = 2160;
  830.       } else {
  831.         maxResolution.width = 1920;
  832.         maxResolution.height = 1080;
  833.       }
  834.     } else {
  835.       // For Xbox and UWP apps.
  836.       let winRT = undefined;
  837.       try {
  838.         // Try to access to WinRT for WebView, if it's not defined,
  839.         // try to access to WinRT for WebView2, if it's not defined either,
  840.         // let it throw.
  841.         if (typeof Windows !== 'undefined') {
  842.           winRT = Windows;
  843.         } else {
  844.           winRT = chrome.webview.hostObjects.sync.Windows;
  845.         }
  846.       } catch (e) {}
  847.       if (winRT) {
  848.         maxResolution.width = 1920;
  849.         maxResolution.height = 1080;
  850.         try {
  851.           const protectionCapabilities =
  852.               new winRT.Media.Protection.ProtectionCapabilities();
  853.           const protectionResult =
  854.               winRT.Media.Protection.ProtectionCapabilityResult;
  855.           // isTypeSupported may return "maybe", which means the operation
  856.           // is not completed. This means we need to retry
  857.           // https://learn.microsoft.com/en-us/uwp/api/windows.media.protection.protectioncapabilityresult?view=winrt-22621
  858.           let result = null;
  859.           const type =
  860.               'video/mp4;codecs="hvc1,mp4a";features="decode-res-x=3840,' +
  861.               'decode-res-y=2160,decode-bitrate=20000,decode-fps=30,' +
  862.               'decode-bpc=10,display-res-x=3840,display-res-y=2160,' +
  863.               'display-bpc=8"';
  864.           const keySystem = 'com.microsoft.playready.recommendation';
  865.           do {
  866.             result = protectionCapabilities.isTypeSupported(type, keySystem);
  867.           } while (result === protectionResult.maybe);
  868.           if (result === protectionResult.probably) {
  869.             maxResolution.width = 3840;
  870.             maxResolution.height = 2160;
  871.           }
  872.         } catch (e) {
  873.           shaka.log.alwaysWarn('Xbox: Error detecting screen size, default ' +
  874.               'screen size 1920x1080.');
  875.         }
  876.       } else if (Platform.isXboxOne()) {
  877.         maxResolution.width = 1920;
  878.         maxResolution.height = 1080;
  879.         shaka.log.alwaysWarn('Xbox: Error detecting screen size, default ' +
  880.             'screen size 1920x1080.');
  881.       }
  882.     }
  883.     return maxResolution;
  884.   }
  885. };
  887. /** @private {shaka.util.Timer} */
  888. shaka.util.Platform.cacheExpirationTimer_ = null;
  890. /** @private {HTMLMediaElement} */
  891. shaka.util.Platform.cachedMediaElement_ = null;