Source: lib/media/media_source_capabilities.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.media.Capabilities');
  9. /**
  10.  * @summary
  11.  * This is for capturing all media source capabilities on current platform.
  12.  * And this is for static check and can not be constructed.
  13.  */
  14. shaka.media.Capabilities = class {
  15.   /**
  16.    * Cache browser engine call to improve performance on some poor platforms
  17.    *
  18.    * @param {string} type
  19.    * @return {boolean}
  20.    */
  21.   static isTypeSupported(type) {
  22.     const supportMap = shaka.media.Capabilities.MediaSourceTypeSupportMap;
  23.     if (supportMap.has(type)) {
  24.       return supportMap.get(type);
  25.     }
  26.     if (window.ManagedMediaSource) {
  27.       const currentSupport = ManagedMediaSource.isTypeSupported(type);
  28.       supportMap.set(type, currentSupport);
  29.       return currentSupport;
  30.     } else if (window.MediaSource) {
  31.       const currentSupport = MediaSource.isTypeSupported(type);
  32.       supportMap.set(type, currentSupport);
  33.       return currentSupport;
  34.     }
  35.     return false;
  36.   }
  38.   /**
  39.    * Determine support for SourceBuffer.changeType
  40.    * @return {boolean}
  41.    */
  42.   static isChangeTypeSupported() {
  43.     return !!window.SourceBuffer &&
  44.         // eslint-disable-next-line no-restricted-syntax
  45.         !!SourceBuffer.prototype && !!SourceBuffer.prototype.changeType;
  46.   }
  47. };
  49. /**
  50.  * Public it for unit test, and developer could also check the support map.
  51.  * @type {!Map.<string, boolean>}
  52.  */
  53. shaka.media.Capabilities.MediaSourceTypeSupportMap = new Map();