static createQualityInfo(context) {
    const representation = context.representation;
    return {
      bandwidth: context.bandwidth,
      audioSamplingRate: representation.audioSamplingRate,
      codecs: representation.codecs,
      contentType: representation.contentType,
      frameRate: representation.frameRate || null,
      height: representation.height || null,
      mimeType: representation.mimeType,
      channelsCount: representation.numChannels,
      pixelAspectRatio: representation.pixelAspectRatio || null,
      width: representation.width || null,
      label: context.adaptationSet.label || null,
      roles: context.roles || null,
      language: context.adaptationSet.language || null,
    };
  }
Create a MediaQualityInfo object from a Context object.

@param {!shaka.dash.DashParser.Context} context
@return {!shaka.extern.MediaQualityInfo}