sampling: fix off-by-one padding error

amodem/sampling.py

@@ -34,7 +34,7 @@ class Sampler(object):
         self.width = self.interp.width
 
         # TODO: explain indices arithmetic
-        padding = [0.0] * (self.interp.width - 1)
+        padding = [0.0] * self.interp.width
         self.src = itertools.chain(padding, src)
         self.offset = self.interp.width + 1
         self.buff = np.zeros(self.interp.coeff_len)

tests/test_sampling.py

@@ -11,7 +11,7 @@ def test_resample():
     dst = BytesIO()
     sampling.resample(src=src, dst=dst, df=0.0)
     y = common.loads(dst.getvalue())
-    err = x[1:len(y)+1] - y
+    err = x[:len(y)] - y
     assert np.max(np.abs(err)) < 1e-4
 
     dst = BytesIO()