Cepstral Pitch Tracker

        /// Just constructed, will provisionally accept any estimate

        New,

        /// Accepted at least one estimate, but not enough evidence to satisfy

        Provisional,

        /// Could not find enough consistency in offered estimates

        Rejected,

        /// Have accepted enough consistent estimates to satisfy hypothesis

        Satisfied,

        /// Have been satisfied, but evidence has now changed: we're done

        Expired

        double freq;

        double confidence;

        double freq;

        Vamp::RealTime time;

        Vamp::RealTime duration;