boost::shared_ptr<Encoder> _encoder;
std::pair<boost::shared_ptr<VideoDecoder>, boost::shared_ptr<AudioDecoder> > _da;
std::pair<boost::shared_ptr<VideoDecoder>, boost::shared_ptr<AudioDecoder> > _db;
boost::shared_ptr<Encoder> _encoder;
std::pair<boost::shared_ptr<VideoDecoder>, boost::shared_ptr<AudioDecoder> > _da;
std::pair<boost::shared_ptr<VideoDecoder>, boost::shared_ptr<AudioDecoder> > _db;