static parseAVCC(codecBase, reader, boxName) {
    const Mp4BoxParsers = shaka.util.Mp4BoxParsers;
    reader.skip(1); // Skip "configurationVersion"
    const codec = codecBase + '.' +
        Mp4BoxParsers.toHex_(reader.readUint8()) +
        Mp4BoxParsers.toHex_(reader.readUint8()) +
        Mp4BoxParsers.toHex_(reader.readUint8());
    return {codec};
  }
Parses a AVCC box.
@param {string} codecBase
@param {!shaka.util.DataViewReader} reader
@param {string} boxName
@return {!shaka.util.ParsedAVCCBox}