class F0Predictor(object):
    def compute_f0(self,wav,p_len):
        '''
        input: wav:[signal_length]
               p_len:int
        output: f0:[signal_length//hop_length]
        '''
        pass

    def compute_f0_uv(self,wav,p_len):
        '''
        input: wav:[signal_length]
               p_len:int
        output: f0:[signal_length//hop_length],uv:[signal_length//hop_length]
        '''
        pass