test_audioop.py 文件源码

def test_ulaw2lin(self):
        encoded = b'\x00\x0e\x28\x3f\x57\x6a\x76\x7c\x7e\x7f'\
                  b'\x80\x8e\xa8\xbf\xd7\xea\xf6\xfc\xfe\xff'
        src = [-8031, -4447, -1471, -495, -163, -53, -18, -6, -2, 0,
               8031, 4447, 1471, 495, 163, 53, 18, 6, 2, 0]
        for w in 1, 2, 4:
            self.assertEqual(audioop.ulaw2lin(encoded, w),
                             packs[w](*(x << (w * 8) >> 14 for x in src)))

        # Current u-law implementation has two codes fo 0: 0x7f and 0xff.
        encoded = bytes(range(127)) + bytes(range(128, 256))
        for w in 2, 4:
            decoded = audioop.ulaw2lin(encoded, w)
            self.assertEqual(audioop.lin2ulaw(decoded, w), encoded)