@playkit-js/kaltura-player-js/src/common/utils/media-capabilities.ts

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import { getLogger } from '@playkit-js/playkit-js';
import { DRMSupportedObject, HEVCConfigObject, HEVCSupportedObject, MediaCapabilitiesObject, SupportedOptionsType } from '../../types';

const CONTENT_TYPE_AVC_CODEC: string = 'video/mp4;codecs="avc1.42E01E"';
const DRM_SCHEME_LIST: Array<[string, string]> = [
  ['widevine', 'com.widevine.alpha'],
  ['playready', 'com.microsoft.playready'],
  ['fairplay', 'com.apple.fps']
];
const CONTENT_TYPE_HVC_CODEC: string = 'video/mp4; codecs="hvc1.1.6.L150.90"';
const WIDTH_DEFAULT: number = 1920;
const HEIGHT_DEFAULT: number = 1080;
const BITRATE_DEFAULT: number = 1200000;
const FRAMERATE_DEFAULT: number = 30;

const _logger: any = getLogger('MediaCapabilities');

/**
 * enum for supported options
 * @const
 * @type {Object}
 */
const SupportedOptions: SupportedOptionsType = {
  SUPPORTED: 1,
  NOT_SUPPORTED: 0,
  MAYBE_SUPPORTED: -1
};

/**
 * get the media capabilities
 * @function getMediaCapabilities
 * @param {HEVCConfigObject} hevcConfig - The HEVC configuration to check (optional).
 * @returns {Promise<MediaCapabilitiesObject>} - The media capabilities object.
 * @public
 */
async function getMediaCapabilities(hevcConfig?: HEVCConfigObject): Promise<MediaCapabilitiesObject> {
  let mediaCapabilities;
  try {
    _logger.debug('Starting to get media capabilities...');
    const hevcSupported = await _checkHEVCSupported(hevcConfig);
    const drmSupported = await _checkDRMSupported();
    mediaCapabilities = Object.assign({}, hevcSupported, drmSupported);
    _logger.debug('Finished getting media capabilities ', {
      mediaCapabilities
    });
    return mediaCapabilities;
  } catch (ex) {
    _logger.debug('There was a problem with getting the media capabilities, ', ex.message);
    mediaCapabilities = {
      isHEVCSupported: SupportedOptions.NOT_SUPPORTED,
      isPowerEfficient: SupportedOptions.NOT_SUPPORTED,
      isDRMSupported: SupportedOptions.NOT_SUPPORTED,
      supportedDRMs: []
    };
    _logger.debug('Returning media capabilities defaults ', {
      mediaCapabilities
    });
    return mediaCapabilities;
  }
}

/**
 * checks whether and which DRMs are supported by the browser
 * @function _checkDRMSupported
 * @returns {Promise<DRMSupportedObject>} - The DRM supported object.
 * @private
 */
async function _checkDRMSupported(): Promise<DRMSupportedObject> {
  const drmSupportedRes: DRMSupportedObject = {
    isDRMSupported: SupportedOptions.MAYBE_SUPPORTED,
    supportedDRMs: []
  };

  if (!navigator.requestMediaKeySystemAccess) {
    return drmSupportedRes;
  }

  const keySysConfig = [
    {
      initDataTypes: ['cenc'],
      videoCapabilities: [
        {
          contentType: CONTENT_TYPE_AVC_CODEC
        }
      ]
    }
  ];

  const keySystemsMap = new Map<string, string>(DRM_SCHEME_LIST);

  for (const [drm, keySys] of keySystemsMap) {
    try {
      await navigator.requestMediaKeySystemAccess(keySys, keySysConfig);
      drmSupportedRes.supportedDRMs.push(drm);
    } catch (ex) {
      _logger.debug(keySys + ' not supported (' + ex.name + ': ' + ex.message + ').');
    }
  }

  drmSupportedRes.isDRMSupported = drmSupportedRes.supportedDRMs.length > 0 ? SupportedOptions.SUPPORTED : SupportedOptions.NOT_SUPPORTED;
  return drmSupportedRes;
}

/**
 * checks whether the browser supports HEVC codec or not
 * @function _checkHEVCSupported
 * @param {HEVCConfigObject} hevcConfig - The HEVC configuration.
 * @returns {Promise<HEVCSupportedObject>} - The HEVC supported object.
 * @private
 */
async function _checkHEVCSupported(hevcConfig?: HEVCConfigObject): Promise<HEVCSupportedObject> {
  const hevcSupportedRes: HEVCSupportedObject = {
    isHEVCSupported: SupportedOptions.MAYBE_SUPPORTED,
    isPowerEfficient: SupportedOptions.MAYBE_SUPPORTED
  };

  if (!navigator.mediaCapabilities || !navigator.mediaCapabilities.decodingInfo) {
    return hevcSupportedRes;
  }

  const configHvc: MediaDecodingConfiguration = {
    type: 'media-source',
    video: {
      contentType: CONTENT_TYPE_HVC_CODEC,
      width: hevcConfig?.width || WIDTH_DEFAULT,
      height: hevcConfig?.height || HEIGHT_DEFAULT,
      bitrate: hevcConfig?.bitrate || BITRATE_DEFAULT,
      framerate: hevcConfig?.framerate || FRAMERATE_DEFAULT
    }
  };

  try {
    const mediaCapRes = await navigator.mediaCapabilities.decodingInfo(configHvc);
    hevcSupportedRes.isHEVCSupported = mediaCapRes.supported ? SupportedOptions.SUPPORTED : SupportedOptions.NOT_SUPPORTED;
    hevcSupportedRes.isPowerEfficient = mediaCapRes.powerEfficient ? SupportedOptions.SUPPORTED : SupportedOptions.NOT_SUPPORTED;
  } catch (ex) {
    _logger.debug('Failed to get the media capabilities from navigator. (' + ex.name + ': ' + ex.message + ').');
    hevcSupportedRes.isHEVCSupported = SupportedOptions.MAYBE_SUPPORTED;
    hevcSupportedRes.isPowerEfficient = SupportedOptions.MAYBE_SUPPORTED;
  }

  return hevcSupportedRes;
}

export default getMediaCapabilities;