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.log');
  10. goog.require('shaka.util.DrmUtils');
  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 Google Chromecast.
  210.    *
  211.    * @return {boolean}
  212.    */
  213.   static isChromecast() {
  214.     return shaka.util.Platform.userAgentContains_('CrKey');
  215.   }
  217.   /**
  218.    * Check if the current platform is a Google Chromecast with Android
  219.    * (i.e. Chromecast with GoogleTV).
  220.    *
  221.    * @return {boolean}
  222.    */
  223.   static isAndroidCastDevice() {
  224.     const Platform = shaka.util.Platform;
  225.     return Platform.isChromecast() && Platform.isAndroid();
  226.   }
  228.   /**
  229.    * Check if the current platform is a Google Chromecast with Fuchsia
  230.    * (i.e. Google Nest Hub).
  231.    *
  232.    * @return {boolean}
  233.    */
  234.   static isFuchsiaCastDevice() {
  235.     const Platform = shaka.util.Platform;
  236.     return Platform.isChromecast() && Platform.isFuchsia();
  237.   }
  239.   /**
  240.    * Returns a major version number for Chrome, or Chromium-based browsers.
  241.    *
  242.    * For example:
  243.    *   - Chrome 106.0.5249.61 returns 106.
  244.    *   - Edge 106.0.1370.34 returns 106 (since this is based on Chromium).
  245.    *   - Safari returns null (since this is independent of Chromium).
  246.    *
  247.    * @return {?number} A major version number or null if not Chromium-based.
  248.    */
  249.   static chromeVersion() {
  250.     if (!shaka.util.Platform.isChrome()) {
  251.       return null;
  252.     }
  254.     // Looking for something like "Chrome/106.0.0.0".
  255.     const match = navigator.userAgent.match(/Chrome\/(\d+)/);
  256.     if (match) {
  257.       return parseInt(match[1], /* base= */ 10);
  258.     }
  260.     return null;
  261.   }
  263.   /**
  264.    * Check if the current platform is Google Chrome.
  265.    *
  266.    * @return {boolean}
  267.    */
  268.   static isChrome() {
  269.     // The Edge Legacy user agent will also contain the "Chrome" keyword, so we
  270.     // need to make sure this is not Edge Legacy.
  271.     return shaka.util.Platform.userAgentContains_('Chrome') &&
  272.            !shaka.util.Platform.isLegacyEdge();
  273.   }
  275.   /**
  276.    * Check if the current platform is Firefox.
  277.    *
  278.    * @return {boolean}
  279.    */
  280.   static isFirefox() {
  281.     return shaka.util.Platform.userAgentContains_('Firefox');
  282.   }
  284.   /**
  285.    * Check if the current platform is from Apple.
  286.    *
  287.    * Returns true on all iOS browsers and on desktop Safari.
  288.    *
  289.    * Returns false for non-Safari browsers on macOS, which are independent of
  290.    * Apple.
  291.    *
  292.    * @return {boolean}
  293.    */
  294.   static isApple() {
  295.     return !!navigator.vendor && navigator.vendor.includes('Apple') &&
  296.         !shaka.util.Platform.isTizen() &&
  297.         !shaka.util.Platform.isEOS() &&
  298.         !shaka.util.Platform.isAPL() &&
  299.         !shaka.util.Platform.isVirginMedia() &&
  300.         !shaka.util.Platform.isOrange() &&
  301.         !shaka.util.Platform.isPS4() &&
  302.         !shaka.util.Platform.isAmazonFireTV() &&
  303.         !shaka.util.Platform.isComcastX1() &&
  304.         !shaka.util.Platform.isZenterio() &&
  305.         !shaka.util.Platform.isSkyQ();
  306.   }
  308.   /**
  309.    * Check if the current platform is Playstation 5.
  310.    *
  311.    * Returns true on Playstation 5 browsers.
  312.    *
  313.    * Returns false for Playstation 5 browsers
  314.    *
  315.    * @return {boolean}
  316.    */
  317.   static isPS5() {
  318.     return shaka.util.Platform.userAgentContains_('PlayStation 5');
  319.   }
  321.   /**
  322.    * Check if the current platform is Playstation 4.
  323.    */
  324.   static isPS4() {
  325.     return shaka.util.Platform.userAgentContains_('PlayStation 4');
  326.   }
  328.   /**
  329.    * Check if the current platform is Hisense.
  330.    */
  331.   static isHisense() {
  332.     return shaka.util.Platform.userAgentContains_('Hisense') ||
  333.         shaka.util.Platform.userAgentContains_('VIDAA');
  334.   }
  336.   /**
  337.    * Check if the current platform is Virgin Media device.
  338.    */
  339.   static isVirginMedia() {
  340.     return shaka.util.Platform.userAgentContains_('VirginMedia');
  341.   }
  343.   /**
  344.    * Check if the current platform is Orange.
  345.    */
  346.   static isOrange() {
  347.     return shaka.util.Platform.userAgentContains_('SOPOpenBrowser');
  348.   }
  350.   /**
  351.    * Check if the current platform is SkyQ STB.
  352.    */
  353.   static isSkyQ() {
  354.     return shaka.util.Platform.userAgentContains_('Sky_STB');
  355.   }
  357.   /**
  358.    * Check if the current platform is Amazon Fire TV.
  359.    * https://developer.amazon.com/docs/fire-tv/identify-amazon-fire-tv-devices.html
  360.    *
  361.    * @return {boolean}
  362.    */
  363.   static isAmazonFireTV() {
  364.     return shaka.util.Platform.userAgentContains_('AFT');
  365.   }
  367.   /**
  368.    * Check if the current platform is Comcast X1.
  369.    * @return {boolean}
  370.    */
  371.   static isComcastX1() {
  372.     return shaka.util.Platform.userAgentContains_('WPE');
  373.   }
  375.   /**
  376.    * Check if the current platform is Deutsche Telecom Zenterio STB.
  377.    * @return {boolean}
  378.    */
  379.   static isZenterio() {
  380.     return shaka.util.Platform.userAgentContains_('DT_STB_BCM');
  381.   }
  383.   /**
  384.    * Returns a major version number for Safari, or Safari-based iOS browsers.
  385.    *
  386.    * For example:
  387.    *   - Safari 13.0.4 on macOS returns 13.
  388.    *   - Safari on iOS 13.3.1 returns 13.
  389.    *   - Chrome on iOS 13.3.1 returns 13 (since this is based on Safari/WebKit).
  390.    *   - Chrome on macOS returns null (since this is independent of Apple).
  391.    *
  392.    * Returns null on Firefox on iOS, where this version information is not
  393.    * available.
  394.    *
  395.    * @return {?number} A major version number or null if not iOS.
  396.    */
  397.   static safariVersion() {
  398.     // All iOS browsers and desktop Safari will return true for isApple().
  399.     if (!shaka.util.Platform.isApple()) {
  400.       return null;
  401.     }
  403.     // This works for iOS Safari and desktop Safari, which contain something
  404.     // like "Version/13.0" indicating the major Safari or iOS version.
  405.     let match = navigator.userAgent.match(/Version\/(\d+)/);
  406.     if (match) {
  407.       return parseInt(match[1], /* base= */ 10);
  408.     }
  410.     // This works for all other browsers on iOS, which contain something like
  411.     // "OS 13_3" indicating the major & minor iOS version.
  412.     match = navigator.userAgent.match(/OS (\d+)(?:_\d+)?/);
  413.     if (match) {
  414.       return parseInt(match[1], /* base= */ 10);
  415.     }
  417.     return null;
  418.   }
  420.   /**
  421.    * Check if the current platform is Apple Safari
  422.    * or Safari-based iOS browsers.
  423.    *
  424.    * @return {boolean}
  425.    */
  426.   static isSafari() {
  427.     return !!shaka.util.Platform.safariVersion();
  428.   }
  430.   /**
  431.    * Check if the current platform is an EOS set-top box.
  432.    *
  433.    * @return {boolean}
  434.    */
  435.   static isEOS() {
  436.     return shaka.util.Platform.userAgentContains_('PC=EOS');
  437.   }
  439.   /**
  440.    * Check if the current platform is an APL set-top box.
  441.    *
  442.    * @return {boolean}
  443.    */
  444.   static isAPL() {
  445.     return shaka.util.Platform.userAgentContains_('PC=APL');
  446.   }
  448.   /**
  449.    * Guesses if the platform is a mobile one (iOS or Android).
  450.    *
  451.    * @return {boolean}
  452.    */
  453.   static isMobile() {
  454.     if (/(?:iPhone|iPad|iPod|Android)/.test(navigator.userAgent)) {
  455.       // This is Android, iOS, or iPad < 13.
  456.       return true;
  457.     }
  459.     // Starting with iOS 13 on iPad, the user agent string no longer has the
  460.     // word "iPad" in it.  It looks very similar to desktop Safari.  This seems
  461.     // to be intentional on Apple's part.
  462.     // See: https://forums.developer.apple.com/thread/119186
  463.     //
  464.     // So if it's an Apple device with multi-touch support, assume it's a mobile
  465.     // device.  If some future iOS version starts masking their user agent on
  466.     // both iPhone & iPad, this clause should still work.  If a future
  467.     // multi-touch desktop Mac is released, this will need some adjustment.
  468.     //
  469.     // As of January 2020, this is mainly used to adjust the default UI config
  470.     // for mobile devices, so it's low risk if something changes to break this
  471.     // detection.
  472.     return shaka.util.Platform.isApple() && navigator.maxTouchPoints > 1;
  473.   }
  475.   /**
  476.    * Return true if the platform is a Mac, regardless of the browser.
  477.    *
  478.    * @return {boolean}
  479.    */
  480.   static isMac() {
  481.     // Try the newer standard first.
  482.     if (navigator.userAgentData && navigator.userAgentData.platform) {
  483.       return navigator.userAgentData.platform.toLowerCase() == 'macos';
  484.     }
  485.     // Fall back to the old API, with less strict matching.
  486.     if (!navigator.platform) {
  487.       return false;
  488.     }
  489.     return navigator.platform.toLowerCase().includes('mac');
  490.   }
  492.   /**
  493.    * Return true if the platform is a VisionOS.
  494.    *
  495.    * @return {boolean}
  496.    */
  497.   static isVisionOS() {
  498.     if (!shaka.util.Platform.isMac()) {
  499.       return false;
  500.     }
  501.     if (!('xr' in navigator)) {
  502.       return false;
  503.     }
  504.     return true;
  505.   }
  507.   /**
  508.    * Return true if the platform is a Windows, regardless of the browser.
  509.    *
  510.    * @return {boolean}
  511.    */
  512.   static isWindows() {
  513.     // Try the newer standard first.
  514.     if (navigator.userAgentData && navigator.userAgentData.platform) {
  515.       return navigator.userAgentData.platform.toLowerCase() == 'windows';
  516.     }
  517.     // Fall back to the old API, with less strict matching.
  518.     if (!navigator.platform) {
  519.       return false;
  520.     }
  521.     return navigator.platform.toLowerCase().includes('win32');
  522.   }
  524.   /**
  525.    * Return true if the platform is a Android, regardless of the browser.
  526.    *
  527.    * @return {boolean}
  528.    */
  529.   static isAndroid() {
  530.     return shaka.util.Platform.userAgentContains_('Android');
  531.   }
  533.   /**
  534.    * Return true if the platform is a Fuchsia, regardless of the browser.
  535.    *
  536.    * @return {boolean}
  537.    */
  538.   static isFuchsia() {
  539.     return shaka.util.Platform.userAgentContains_('Fuchsia');
  540.   }
  542.   /**
  543.    * Return true if the platform is controlled by a remote control.
  544.    *
  545.    * @return {boolean}
  546.    */
  547.   static isSmartTV() {
  548.     const Platform = shaka.util.Platform;
  549.     if (Platform.isTizen() || Platform.isWebOS() ||
  550.         Platform.isXboxOne() || Platform.isPS4() ||
  551.         Platform.isPS5() || Platform.isAmazonFireTV() ||
  552.         Platform.isEOS() || Platform.isAPL() ||
  553.         Platform.isVirginMedia() || Platform.isOrange() ||
  554.         Platform.isComcastX1() || Platform.isChromecast() ||
  555.         Platform.isHisense() || Platform.isZenterio()) {
  556.       return true;
  557.     }
  558.     return false;
  559.   }
  561.   /**
  562.    * Check if the user agent contains a key. This is the best way we know of
  563.    * right now to detect platforms. If there is a better way, please send a
  564.    * PR.
  565.    *
  566.    * @param {string} key
  567.    * @return {boolean}
  568.    * @private
  569.    */
  570.   static userAgentContains_(key) {
  571.     const userAgent = navigator.userAgent || '';
  572.     return userAgent.includes(key);
  573.   }
  575.   /**
  576.    * For canPlayType queries, we just need any instance.
  577.    *
  578.    * First, use a cached element from a previous query.
  579.    * Second, search the page for one.
  580.    * Third, create a temporary one.
  581.    *
  582.    * Cached elements expire in one second so that they can be GC'd or removed.
  583.    *
  584.    * @return {!HTMLMediaElement}
  585.    */
  586.   static anyMediaElement() {
  587.     const Platform = shaka.util.Platform;
  588.     if (Platform.cachedMediaElement_) {
  589.       return Platform.cachedMediaElement_;
  590.     }
  592.     if (!Platform.cacheExpirationTimer_) {
  593.       Platform.cacheExpirationTimer_ = new shaka.util.Timer(() => {
  594.         Platform.cachedMediaElement_ = null;
  595.       });
  596.     }
  598.     Platform.cachedMediaElement_ = /** @type {HTMLMediaElement} */(
  599.       document.getElementsByTagName('video')[0] ||
  600.       document.getElementsByTagName('audio')[0]);
  602.     if (!Platform.cachedMediaElement_) {
  603.       Platform.cachedMediaElement_ = /** @type {!HTMLMediaElement} */(
  604.         document.createElement('video'));
  605.     }
  607.     Platform.cacheExpirationTimer_.tickAfter(/* seconds= */ 1);
  608.     return Platform.cachedMediaElement_;
  609.   }
  611.   /**
  612.    * Returns true if the platform requires encryption information in all init
  613.    * segments.  For such platforms, MediaSourceEngine will attempt to work
  614.    * around a lack of such info by inserting fake encryption information into
  615.    * initialization segments.
  616.    *
  617.    * @param {?string} keySystem
  618.    * @return {boolean}
  619.    * @see https://github.com/shaka-project/shaka-player/issues/2759
  620.    */
  621.   static requiresEncryptionInfoInAllInitSegments(keySystem) {
  622.     const Platform = shaka.util.Platform;
  623.     const isPlayReady = shaka.util.DrmUtils.isPlayReadyKeySystem(keySystem);
  624.     return Platform.isTizen() || Platform.isXboxOne() || Platform.isOrange() ||
  625.       (Platform.isEdge() && Platform.isWindows() && isPlayReady);
  626.   }
  628.   /**
  629.    * Returns true if the platform supports SourceBuffer "sequence mode".
  630.    *
  631.    * @return {boolean}
  632.    */
  633.   static supportsSequenceMode() {
  634.     const Platform = shaka.util.Platform;
  635.     if (Platform.isTizen3() || Platform.isTizen2() ||
  636.         Platform.isWebOS3() || Platform.isPS4()) {
  637.       return false;
  638.     }
  639.     return true;
  640.   }
  642.   /**
  643.    * Returns if codec switching SMOOTH is known reliable device support.
  644.    *
  645.    * Some devices are known not to support `MediaSource.changeType`
  646.    * well. These devices should use the reload strategy. If a device
  647.    * reports that it supports `changeType` but support it unreliably
  648.    * it should be added to this list.
  649.    *
  650.    * @return {boolean}
  651.    */
  652.   static supportsSmoothCodecSwitching() {
  653.     const Platform = shaka.util.Platform;
  654.     if (Platform.isTizen2() || Platform.isTizen3() || Platform.isTizen4() ||
  655.         Platform.isTizen5() || Platform.isTizen6() || Platform.isWebOS3() ||
  656.         Platform.isWebOS4() || Platform.isWebOS5() || Platform.isPS4() ||
  657.         Platform.isPS5()) {
  658.       return false;
  659.     }
  660.     // Older chromecasts without GoogleTV seem to not support SMOOTH properly.
  661.     if (Platform.isChromecast() && !Platform.isAndroidCastDevice() &&
  662.         !Platform.isFuchsiaCastDevice()) {
  663.       return false;
  664.     }
  665.     // See: https://chromium-review.googlesource.com/c/chromium/src/+/4577759
  666.     if (Platform.isWindows() && Platform.isEdge()) {
  667.       return false;
  668.     }
  669.     return true;
  670.   }
  672.   /**
  673.    * On some platforms, such as v1 Chromecasts, the act of seeking can take a
  674.    * significant amount of time.
  675.    *
  676.    * @return {boolean}
  677.    */
  678.   static isSeekingSlow() {
  679.     const Platform = shaka.util.Platform;
  680.     if (Platform.isChromecast()) {
  681.       if (Platform.isAndroidCastDevice()) {
  682.         // Android-based Chromecasts are new enough to not be a problem.
  683.         return false;
  684.       } else {
  685.         return true;
  686.       }
  687.     }
  688.     return false;
  689.   }
  691.   /**
  692.    * Returns true if MediaKeys is polyfilled
  693.    *
  694.    * @param {string=} polyfillType
  695.    * @return {boolean}
  696.    */
  697.   static isMediaKeysPolyfilled(polyfillType) {
  698.     if (polyfillType) {
  699.       return polyfillType === window.shakaMediaKeysPolyfill;
  700.     }
  701.     return !!window.shakaMediaKeysPolyfill;
  702.   }
  705.   /**
  706.    * Detect the maximum resolution that the platform's hardware can handle.
  707.    *
  708.    * @return {!Promise.<shaka.extern.Resolution>}
  709.    */
  710.   static async detectMaxHardwareResolution() {
  711.     const Platform = shaka.util.Platform;
  713.     /** @type {shaka.extern.Resolution} */
  714.     const maxResolution = {
  715.       width: Infinity,
  716.       height: Infinity,
  717.     };
  719.     if (Platform.isChromecast()) {
  720.       // In our tests, the original Chromecast seems to have trouble decoding
  721.       // above 1080p. It would be a waste to select a higher res anyway, given
  722.       // that the device only outputs 1080p to begin with.
  723.       // Chromecast has an extension to query the device/display's resolution.
  724.       const hasCanDisplayType = window.cast && cast.__platform__ &&
  725.           cast.__platform__.canDisplayType;
  727.       // Some hub devices can only do 720p. Default to that.
  728.       maxResolution.width = 1280;
  729.       maxResolution.height = 720;
  731.       try {
  732.         if (hasCanDisplayType && await cast.__platform__.canDisplayType(
  733.             'video/mp4; codecs="avc1.640028"; width=3840; height=2160')) {
  734.           // The device and display can both do 4k. Assume a 4k limit.
  735.           maxResolution.width = 3840;
  736.           maxResolution.height = 2160;
  737.         } else if (hasCanDisplayType && await cast.__platform__.canDisplayType(
  738.             'video/mp4; codecs="avc1.640028"; width=1920; height=1080')) {
  739.           // Most Chromecasts can do 1080p.
  740.           maxResolution.width = 1920;
  741.           maxResolution.height = 1080;
  742.         }
  743.       } catch (error) {
  744.         // This shouldn't generally happen. Log the error.
  745.         shaka.log.alwaysError('Failed to check canDisplayType:', error);
  746.         // Now ignore the error and let the 720p default stand.
  747.       }
  748.     } else if (Platform.isTizen()) {
  749.       maxResolution.width = 1920;
  750.       maxResolution.height = 1080;
  751.       try {
  752.         if (webapis.systeminfo && webapis.systeminfo.getMaxVideoResolution) {
  753.           const maxVideoResolution =
  754.               webapis.systeminfo.getMaxVideoResolution();
  755.           maxResolution.width = maxVideoResolution.width;
  756.           maxResolution.height = maxVideoResolution.height;
  757.         } else {
  758.           if (webapis.productinfo.is8KPanelSupported &&
  759.               webapis.productinfo.is8KPanelSupported()) {
  760.             maxResolution.width = 7680;
  761.             maxResolution.height = 4320;
  762.           } else if (webapis.productinfo.isUdPanelSupported &&
  763.               webapis.productinfo.isUdPanelSupported()) {
  764.             maxResolution.width = 3840;
  765.             maxResolution.height = 2160;
  766.           }
  767.         }
  768.       } catch (e) {
  769.         shaka.log.alwaysWarn('Tizen: Error detecting screen size, default ' +
  770.             'screen size 1920x1080.');
  771.       }
  772.     } else if (Platform.isXboxOne()) {
  773.       maxResolution.width = 1920;
  774.       maxResolution.height = 1080;
  775.       try {
  776.         let winRT = undefined;
  778.         // Try to access to WinRT for WebView, if it's not defined,
  779.         // try to access to WinRT for WebView2, if it's not defined either,
  780.         // let it throw.
  781.         if (typeof Windows !== 'undefined') {
  782.           winRT = Windows;
  783.         } else {
  784.           winRT = chrome.webview.hostObjects.sync.Windows;
  785.         }
  787.         const protectionCapabilities =
  788.             new winRT.Media.Protection.ProtectionCapabilities();
  789.         const protectionResult =
  790.             winRT.Media.Protection.ProtectionCapabilityResult;
  791.         // isTypeSupported may return "maybe", which means the operation is not
  792.         // completed. This means we need to retry
  793.         // https://learn.microsoft.com/en-us/uwp/api/windows.media.protection.protectioncapabilityresult?view=winrt-22621
  794.         let result = null;
  795.         const type =
  796.             'video/mp4;codecs="hvc1,mp4a";features="decode-res-x=3840,' +
  797.             'decode-res-y=2160,decode-bitrate=20000,decode-fps=30,' +
  798.             'decode-bpc=10,display-res-x=3840,display-res-y=2160,' +
  799.             'display-bpc=8"';
  800.         const keySystem = 'com.microsoft.playready.recommendation';
  801.         do {
  802.           result = protectionCapabilities.isTypeSupported(type, keySystem);
  803.         } while (result === protectionResult.maybe);
  804.         if (result === protectionResult.probably) {
  805.           maxResolution.width = 3840;
  806.           maxResolution.height = 2160;
  807.         }
  808.       } catch (e) {
  809.         shaka.log.alwaysWarn('Xbox: Error detecting screen size, default ' +
  810.             'screen size 1920x1080.');
  811.       }
  812.     } else if (Platform.isWebOS()) {
  813.       try {
  814.         const deviceInfo =
  815.         /** @type {{screenWidth: number, screenHeight: number}} */(
  816.             JSON.parse(window.PalmSystem.deviceInfo));
  817.         // WebOS has always been able to do 1080p.  Assume a 1080p limit.
  818.         maxResolution.width = Math.max(1920, deviceInfo['screenWidth']);
  819.         maxResolution.height = Math.max(1080, deviceInfo['screenHeight']);
  820.       } catch (e) {
  821.         shaka.log.alwaysWarn('WebOS: Error detecting screen size, default ' +
  822.             'screen size 1920x1080.');
  823.         maxResolution.width = 1920;
  824.         maxResolution.height = 1080;
  825.       }
  826.     } else if (Platform.isHisense()) {
  827.       // eslint-disable-next-line new-cap
  828.       if (window.Hisense_Get4KSupportState &&
  829.           // eslint-disable-next-line new-cap
  830.           window.Hisense_Get4KSupportState()) {
  831.         maxResolution.width = 3840;
  832.         maxResolution.height = 2160;
  833.       } else {
  834.         maxResolution.width = 1920;
  835.         maxResolution.height = 1080;
  836.       }
  837.     } else if (Platform.isPS4() || Platform.isPS5()) {
  838.       let supports4K = false;
  839.       try {
  840.         const result = await window.msdk.device.getDisplayInfo();
  841.         supports4K = result.resolution === '4K';
  842.       } catch (e) {
  843.         try {
  844.           const result = await window.msdk.device.getDisplayInfoImmediate();
  845.           supports4K = result.resolution === '4K';
  846.         } catch (e) {
  847.           shaka.log.alwaysWarn(
  848.               'PlayStation: Failed to get the display info:', e);
  849.         }
  850.       }
  851.       if (supports4K) {
  852.         maxResolution.width = 3840;
  853.         maxResolution.height = 2160;
  854.       } else {
  855.         maxResolution.width = 1920;
  856.         maxResolution.height = 1080;
  857.       }
  858.     }
  859.     return maxResolution;
  860.   }
  861. };
  863. /** @private {shaka.util.Timer} */
  864. shaka.util.Platform.cacheExpirationTimer_ = null;
  866. /** @private {HTMLMediaElement} */
  867. shaka.util.Platform.cachedMediaElement_ = null;