procedural.py 文件源码

def _generate_data(self, bytes, offset):
        # XXX TODO consider offset
        if self._bytes_per_sample == 1:
            samples = bytes
            value = 0
            amplitude = 255
            data = (ctypes.c_ubyte * samples)()
        else:
            samples = bytes >> 1
            value = -32768
            amplitude = 65535
            data = (ctypes.c_short * samples)()
        period = self.audio_format.sample_rate / self.frequency / 2
        count = 0
        for i in range(samples):
            count += 1
            if count == period:
                value = amplitude - value
                count = 0
            data[i] = future_round(value)
        return data