test: add noisy channel support

amodem/test/test_full.py

@@ -1,15 +1,20 @@
 import os
 from cStringIO import StringIO
+import numpy as np
 
 import send
 import recv
 import common
 
+import logging
+logging.basicConfig(level=logging.DEBUG,
+                    format='%(asctime)s %(levelname)-12s %(message)s')
+
 class Args(object):
     def __init__(self, **kwargs):
         self.__dict__.update(kwargs)
 
-def run(chan, size):
+def run(size, chan):
     tx_data = os.urandom(size)
     tx_audio = StringIO()
     send.main(Args(silence_start=1, silence_stop=1, input=StringIO(tx_data), output=tx_audio))
@@ -27,7 +32,18 @@ def run(chan, size):
     assert rx_data == tx_data
 
 def test_small():
-    run(chan=lambda x: x, size=1024)
+    run(1024, lambda x: x)
 
 def test_large():
-    run(chan=lambda x: x, size=64 << 10)
+    run(54321, lambda x: x)
+
+def test_attenuation():
+    run(5120, lambda x: x * 0.1)
+
+def test_low_noise():
+    r = np.random.RandomState(seed=0)
+    run(5120, lambda x: x + r.normal(size=len(x), scale=0.0001))
+
+def test_medium_noise():
+    r = np.random.RandomState(seed=0)
+    run(5120, lambda x: x + r.normal(size=len(x), scale=0.001))