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.     const mediaSource = window.ManagedMediaSource || window.MediaSource;
  27.     if (mediaSource) {
  28.       const currentSupport = mediaSource.isTypeSupported(type);
  29.       supportMap.set(type, currentSupport);
  30.       return currentSupport;
  31.     }
  32.     return false;
  33.   }
  35.   /**
  36.    * Determine support for SourceBuffer.changeType
  37.    * @return {boolean}
  38.    */
  39.   static isChangeTypeSupported() {
  40.     const sourceBuffer = window.ManagedSourceBuffer || window.SourceBuffer;
  41.     return !!sourceBuffer &&
  42.         // eslint-disable-next-line no-restricted-syntax
  43.         !!sourceBuffer.prototype && !!sourceBuffer.prototype.changeType;
  44.   }
  46.   /**
  47.    * Determine support for MediaSource.setLiveSeekableRange and
  48.    * MediaSource.clearLiveSeekableRange, which can allow for a media element
  49.    * duration of Infinite by providing a non-infinite seekable range.
  50.    *
  51.    * @return {boolean}
  52.    */
  53.   static isInfiniteLiveStreamDurationSupported() {
  54.     const mediaSource = window.ManagedMediaSource || window.MediaSource;
  55.     // eslint-disable-next-line no-restricted-syntax
  56.     if (mediaSource && mediaSource.prototype) {
  57.       // eslint-disable-next-line no-restricted-syntax
  58.       return !!mediaSource.prototype.setLiveSeekableRange &&
  59.       // eslint-disable-next-line no-restricted-syntax
  60.           !!mediaSource.prototype.clearLiveSeekableRange;
  61.     }
  62.     return false;
  63.   }
  64. };
  66. /**
  67.  * Public it for unit test, and developer could also check the support map.
  68.  * @type {!Map<string, boolean>}
  69.  */
  70. shaka.media.Capabilities.MediaSourceTypeSupportMap = new Map();