'0 means unknown'

@property
def sample_rate(self):

    if (self.sbrPresentFlag == 1):
        return self.extensionSamplingFrequency
    elif (self.sbrPresentFlag == 0):
        return self.samplingFrequency
    else:
        aot_can_sbr = (1, 2, 3, 4, 6, 17, 19, 20, 22)
        if (self.audioObjectType not in aot_can_sbr):
            return self.samplingFrequency
        if (self.samplingFrequency > 24000):
            return self.samplingFrequency
        return 0
