Source: lib/polyfill/mediasource.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.polyfill.MediaSource');
  9. goog.require('shaka.log');
  10. goog.require('shaka.polyfill');
  11. goog.require('shaka.util.MimeUtils');
  12. goog.require('shaka.util.Platform');
  14. /**
  15.  * @summary A polyfill to patch MSE bugs.
  16.  * @export
  17.  */
  18. shaka.polyfill.MediaSource = class {
  19.   /**
  20.    * Install the polyfill if needed.
  21.    * @export
  22.    */
  23.   static install() {
  24.     shaka.log.debug('MediaSource.install');
  26.     // MediaSource bugs are difficult to detect without checking for the
  27.     // affected platform.  SourceBuffer is not always exposed on window, for
  28.     // example, and instances are only accessible after setting up MediaSource
  29.     // on a video element.  Because of this, we use UA detection and other
  30.     // platform detection tricks to decide which patches to install.
  31.     const safariVersion = shaka.util.Platform.safariVersion();
  33.     if (!window.MediaSource && !window.ManagedMediaSource) {
  34.       shaka.log.info('No MSE implementation available.');
  35.     } else if (safariVersion && window.MediaSource) {
  36.       // NOTE:  shaka.Player.isBrowserSupported() has its own restrictions on
  37.       // Safari version.
  38.       if (safariVersion <= 12) {
  39.         shaka.log.info('Patching Safari 8-12 MSE bugs.');
  40.         // Safari 8 does not implement appendWindowEnd.
  41.         // Safari 10 fires spurious 'updateend' events after endOfStream().
  42.         // We do not have patches for these bugs here.
  44.         // Safari 8-12 do not correctly implement abort() on SourceBuffer.
  45.         // Calling abort() before appending a segment causes that segment to be
  46.         // incomplete in the buffer.
  47.         // Bug filed: https://bugs.webkit.org/show_bug.cgi?id=165342
  48.         shaka.polyfill.MediaSource.stubAbort_();
  50.         // If you remove up to a keyframe, Safari 8-12 incorrectly will also
  51.         // remove that keyframe and the content up to the next.
  52.         // Offsetting the end of the removal range seems to help.
  53.         // Bug filed: https://bugs.webkit.org/show_bug.cgi?id=177884
  54.         shaka.polyfill.MediaSource.patchRemovalRange_();
  55.       } else if (safariVersion <= 15) {
  56.         shaka.log.info('Patching Safari 13 & 14 & 15 MSE bugs.');
  57.         // Safari 13 does not correctly implement abort() on SourceBuffer.
  58.         // Calling abort() before appending a segment causes that segment to be
  59.         // incomplete in the buffer.
  60.         // Bug filed: https://bugs.webkit.org/show_bug.cgi?id=165342
  61.         shaka.polyfill.MediaSource.stubAbort_();
  62.       }
  63.     } else if (shaka.util.Platform.isZenterio()) {
  64.       // Zenterio uses WPE based on Webkit 607.x.x which do not correctly
  65.       // implement abort() on SourceBuffer.
  66.       // Calling abort() before appending a segment causes that segment to be
  67.       // incomplete in the buffer.
  68.       // Bug filed: https://bugs.webkit.org/show_bug.cgi?id=165342
  69.       shaka.polyfill.MediaSource.stubAbort_();
  70.       // If you remove up to a keyframe, Webkit 607.x.x incorrectly will also
  71.       // remove that keyframe and the content up to the next.
  72.       // Offsetting the end of the removal range seems to help.
  73.       // Bug filed: https://bugs.webkit.org/show_bug.cgi?id=177884
  74.       shaka.polyfill.MediaSource.patchRemovalRange_();
  75.     } else if (shaka.util.Platform.isTizen2() ||
  76.         shaka.util.Platform.isTizen3() ||
  77.         shaka.util.Platform.isTizen4()) {
  78.       shaka.log.info('Rejecting Opus.');
  79.       // Tizen's implementation of MSE does not work well with opus. To prevent
  80.       // the player from trying to play opus on Tizen, we will override media
  81.       // source to always reject opus content.
  82.       shaka.polyfill.MediaSource.rejectCodec_('opus');
  83.     } else {
  84.       shaka.log.info('Using native MSE as-is.');
  85.     }
  87.     if (window.MediaSource || window.ManagedMediaSource) {
  88.       // TS content is broken on all browsers in general.
  89.       // See https://github.com/shaka-project/shaka-player/issues/4955
  90.       // See https://github.com/shaka-project/shaka-player/issues/5278
  91.       // See https://github.com/shaka-project/shaka-player/issues/6334
  92.       shaka.polyfill.MediaSource.rejectContainer_('mp2t');
  93.     }
  95.     if (window.MediaSource &&
  96.         MediaSource.isTypeSupported('video/webm; codecs="vp9"') &&
  97.         !MediaSource.isTypeSupported('video/webm; codecs="vp09.00.10.08"')) {
  98.       shaka.log.info('Patching vp09 support queries.');
  99.       // Only the old, deprecated style of VP9 codec strings is supported.
  100.       // This occurs on older smart TVs.
  101.       // Patch isTypeSupported to translate the new strings into the old one.
  102.       shaka.polyfill.MediaSource.patchVp09_();
  103.     }
  104.   }
  106.   /**
  107.    * Stub out abort().  On some buggy MSE implementations, calling abort()
  108.    * causes various problems.
  109.    *
  110.    * @private
  111.    */
  112.   static stubAbort_() {
  113.     /* eslint-disable no-restricted-syntax */
  114.     const addSourceBuffer = MediaSource.prototype.addSourceBuffer;
  115.     MediaSource.prototype.addSourceBuffer = function(...varArgs) {
  116.       const sourceBuffer = addSourceBuffer.apply(this, varArgs);
  117.       sourceBuffer.abort = function() {}; // Stub out for buggy implementations.
  118.       return sourceBuffer;
  119.     };
  120.     /* eslint-enable no-restricted-syntax */
  121.   }
  123.   /**
  124.    * Patch remove().  On Safari 11, if you call remove() to remove the content
  125.    * up to a keyframe, Safari will also remove the keyframe and all of the data
  126.    * up to the next one. For example, if the keyframes are at 0s, 5s, and 10s,
  127.    * and you tried to remove 0s-5s, it would instead remove 0s-10s.
  128.    *
  129.    * Offsetting the end of the range seems to be a usable workaround.
  130.    *
  131.    * @private
  132.    */
  133.   static patchRemovalRange_() {
  134.     // eslint-disable-next-line no-restricted-syntax
  135.     const originalRemove = SourceBuffer.prototype.remove;
  137.     // eslint-disable-next-line no-restricted-syntax
  138.     SourceBuffer.prototype.remove = function(startTime, endTime) {
  139.       // eslint-disable-next-line no-restricted-syntax
  140.       return originalRemove.call(this, startTime, endTime - 0.001);
  141.     };
  142.   }
  144.   /**
  145.    * Patch |MediaSource.isTypeSupported| to always reject |container|. This is
  146.    * used when we know that we are on a platform that does not work well with
  147.    * a given container.
  148.    *
  149.    * @param {string} container
  150.    * @private
  151.    */
  152.   static rejectContainer_(container) {
  153.     if (window.MediaSource) {
  154.       const isTypeSupported =
  155.           // eslint-disable-next-line no-restricted-syntax
  156.           MediaSource.isTypeSupported.bind(MediaSource);
  158.       MediaSource.isTypeSupported = (mimeType) => {
  159.         const actualContainer = shaka.util.MimeUtils.getContainerType(mimeType);
  160.         return actualContainer != container && isTypeSupported(mimeType);
  161.       };
  162.     }
  164.     if (window.ManagedMediaSource) {
  165.       const isTypeSupportedManaged =
  166.           // eslint-disable-next-line no-restricted-syntax
  167.           ManagedMediaSource.isTypeSupported.bind(ManagedMediaSource);
  169.       window.ManagedMediaSource.isTypeSupported = (mimeType) => {
  170.         const actualContainer = shaka.util.MimeUtils.getContainerType(mimeType);
  171.         return actualContainer != container && isTypeSupportedManaged(mimeType);
  172.       };
  173.     }
  174.   }
  176.   /**
  177.    * Patch |MediaSource.isTypeSupported| to always reject |codec|. This is used
  178.    * when we know that we are on a platform that does not work well with a given
  179.    * codec.
  180.    *
  181.    * @param {string} codec
  182.    * @private
  183.    */
  184.   static rejectCodec_(codec) {
  185.     const isTypeSupported =
  186.         // eslint-disable-next-line no-restricted-syntax
  187.         MediaSource.isTypeSupported.bind(MediaSource);
  189.     MediaSource.isTypeSupported = (mimeType) => {
  190.       const actualCodec = shaka.util.MimeUtils.getCodecBase(mimeType);
  191.       return actualCodec != codec && isTypeSupported(mimeType);
  192.     };
  194.     if (window.ManagedMediaSource) {
  195.       const isTypeSupportedManaged =
  196.           // eslint-disable-next-line no-restricted-syntax
  197.           ManagedMediaSource.isTypeSupported.bind(ManagedMediaSource);
  199.       window.ManagedMediaSource.isTypeSupported = (mimeType) => {
  200.         const actualCodec = shaka.util.MimeUtils.getCodecBase(mimeType);
  201.         return actualCodec != codec && isTypeSupportedManaged(mimeType);
  202.       };
  203.     }
  204.   }
  206.   /**
  207.    * Patch isTypeSupported() to translate vp09 codec strings into vp9, to allow
  208.    * such content to play on older smart TVs.
  209.    *
  210.    * @private
  211.    */
  212.   static patchVp09_() {
  213.     const originalIsTypeSupported = MediaSource.isTypeSupported;
  215.     if (shaka.util.Platform.isWebOS()) {
  216.       // Don't do this on LG webOS as otherwise it is unable
  217.       // to play vp09 at all.
  218.       return;
  219.     }
  221.     MediaSource.isTypeSupported = (mimeType) => {
  222.       // Split the MIME type into its various parameters.
  223.       const pieces = mimeType.split(/ *; */);
  225.       const codecsIndex =
  226.           pieces.findIndex((piece) => piece.startsWith('codecs='));
  227.       if (codecsIndex < 0) {
  228.         // No codec? Call the original without modifying the MIME type.
  229.         return originalIsTypeSupported(mimeType);
  230.       }
  232.       const codecsParam = pieces[codecsIndex];
  233.       const codecs = codecsParam
  234.           .replace('codecs=', '').replace(/"/g, '').split(/\s*,\s*/);
  236.       const vp09Index = codecs.findIndex(
  237.           (codecName) => codecName.startsWith('vp09'));
  238.       if (vp09Index >= 0) {
  239.         // vp09? Replace it with vp9.
  240.         codecs[vp09Index] = 'vp9';
  241.         pieces[codecsIndex] = 'codecs="' + codecs.join(',') + '"';
  242.         mimeType = pieces.join('; ');
  243.       }
  245.       return originalIsTypeSupported(mimeType);
  246.     };
  247.   }
  248. };
  251. shaka.polyfill.register(shaka.polyfill.MediaSource.install);