test_mu_law.py 文件源码

def testEncodeDecodeShift(self):
        x = np.linspace(-1, 1, 1000).astype(np.float32)
        with self.test_session() as sess:
            encoded = mu_law_encode(x, QUANT_LEVELS)
            decoded = mu_law_decode(encoded, QUANT_LEVELS)
            roundtripped = sess.run(decoded)

        # Detect non-unity scaling and non-zero shift in the roundtripped
        # signal by asserting that slope = 1 and y-intercept = 0 of line fit to
        # roundtripped vs x values.
        coeffs = np.polyfit(x, roundtripped, 1)
        slope = coeffs[0]
        y_intercept = coeffs[1]
        EPSILON = 1e-4
        self.assertNear(slope, 1.0, EPSILON)
        self.assertNear(y_intercept, 0.0, EPSILON)