static getCodecs(mimeType) {
    // Parse the basic MIME type from its parameters.
    const pieces = mimeType.split(/ *; */);
    pieces.shift();  // Remove basic MIME type from pieces.

    const codecs = pieces.find((piece) => piece.startsWith('codecs='));
    if (!codecs) {
      return '';
    }

    // The value may be quoted, so remove quotes at the beginning or end.
    const value = codecs.split('=')[1].replace(/^"|"$/g, '');
    return value;
  }
Takes a MIME type and returns the codecs parameter, or an empty string if
there is no codecs parameter.

@param {string} mimeType
@return {string}