From ca14f0862b0884db011f953ed30e3c9c13510dd4 Mon Sep 17 00:00:00 2001
From: Roman Zeyde <roman.zeyde@gmail.com>
Date: Tue, 2 Dec 2014 22:18:24 +0200
Subject: [PATCH] configuration should be specified explicitly

---
 amodem-cli              |  6 ++-
 amodem/config.py        | 83 +++++++++++++++++++++++------------------
 setup.py                | 14 ++-----
 tests/test_calib.py     |  1 +
 tests/test_dsp.py       |  3 +-
 tests/test_equalizer.py |  4 +-
 tests/test_recv.py      |  3 +-
 tests/test_whole.py     |  1 +
 8 files changed, 62 insertions(+), 53 deletions(-)

diff --git a/amodem-cli b/amodem-cli
index b961385..0dbfa42 100755
--- a/amodem-cli
+++ b/amodem-cli
@@ -19,7 +19,7 @@ import logging
 
 log = logging.getLogger('__name__')
 
-from amodem import config
+from amodem.config import bitrates
 from amodem import recv
 from amodem import send
 from amodem import audio
@@ -27,6 +27,10 @@ from amodem import calib
 
 null = open('/dev/null', 'wb')
 
+import os
+bitrate = os.environ.get('BITRATE', 1)
+config = bitrates.get(int(bitrate))
+
 
 def FileType(mode, process=None):
     def opener(fname):
diff --git a/amodem/config.py b/amodem/config.py
index f34430e..02a4b32 100644
--- a/amodem/config.py
+++ b/amodem/config.py
@@ -1,42 +1,51 @@
-Fs = 32000.0  # sampling frequency [Hz]
-Tsym = 0.001  # symbol duration [seconds]
-Nfreq = 8     # number of frequencies used
-Npoints = 64
-F0 = 1e3
-
-# Update default configuration from environment variables
-settings = {k: v for k, v in locals().items() if not k.startswith('_')}
-
-_prefix = 'AMODEM_'
-import os
-for k in settings.keys():
-    v = settings[k]
-    settings[k] = type(v)(os.environ.get(_prefix + k, v))
-locals().update(settings)
-
 import numpy as np
 
-Ts = 1.0 / Fs
-Fsym = 1 / Tsym
-frequencies = F0 + np.arange(Nfreq) * Fsym
-carrier_index = 0
-Fc = frequencies[carrier_index]
-Tc = 1.0 / Fc
 
-Nsym = int(Tsym / Ts)
-baud = int(1 / Tsym)
+class Configuration(object):
+    Fs = 32000.0  # sampling frequency [Hz]
+    Tsym = 0.001  # symbol duration [seconds]
+    Nfreq = 8     # number of frequencies used
+    Npoints = 64
+    F0 = 1e3
 
-bits_per_symbol = np.log2(Npoints)
-assert int(bits_per_symbol) == bits_per_symbol
-bits_per_baud = bits_per_symbol * Nfreq
-modem_bps = baud * bits_per_baud
-carriers = np.array([
-    np.exp(2j * np.pi * f * np.arange(0, Nsym) * Ts) for f in frequencies
-])
+    def __init__(self, **kwargs):
+        self.__dict__.update(**kwargs)
 
-# Hexagonal symbol constellation (optimal "sphere packing")
-Nx = 2 ** int(np.ceil(bits_per_symbol / 2))
-Ny = Npoints // Nx
-symbols = np.array([complex(x, y) for x in range(Nx) for y in range(Ny)])
-symbols = symbols - symbols[-1]/2
-symbols = symbols / np.max(np.abs(symbols))
+        self.Ts = 1.0 / self.Fs
+        self.Fsym = 1 / self.Tsym
+        self.frequencies = self.F0 + np.arange(self.Nfreq) * self.Fsym
+        self.carrier_index = 0
+        self.Fc = self.frequencies[self.carrier_index]
+
+        self.Nsym = int(self.Tsym / self.Ts)
+        self.baud = int(1.0 / self.Tsym)
+
+        bits_per_symbol = np.log2(self.Npoints)
+        assert int(bits_per_symbol) == bits_per_symbol
+        self.bits_per_baud = bits_per_symbol * self.Nfreq
+        self.modem_bps = self.baud * self.bits_per_baud
+        self.carriers = np.array([
+            np.exp(2j * np.pi * f * np.arange(0, self.Nsym) * self.Ts)
+            for f in self.frequencies
+        ])
+
+        # QAM constellation
+        Nx = 2 ** int(np.ceil(bits_per_symbol / 2))
+        Ny = self.Npoints // Nx
+        symbols = np.array([complex(x, y) for x in range(Nx) for y in range(Ny)])
+        symbols = symbols - symbols[-1]/2
+        self.symbols = symbols / np.max(np.abs(symbols))
+
+# MODEM configurations for various bitrates [kbps]
+bitrates = {
+    1: Configuration(F0=8e3, Npoints=2, Nfreq=1),
+    2: Configuration(F0=8e3, Npoints=4, Nfreq=1),
+    4: Configuration(F0=8e3, Npoints=16, Nfreq=1),
+    8: Configuration(F0=8e3, Npoints=16, Nfreq=2),
+    16: Configuration(F0=6e3, Npoints=16, Nfreq=4),
+    32: Configuration(F0=3e3, Npoints=16, Nfreq=8),
+    48: Configuration(F0=3e3, Npoints=64, Nfreq=8),
+}
+
+fastest = lambda: bitrates[max(bitrates)]
+slowest = lambda: bitrates[min(bitrates)]
diff --git a/setup.py b/setup.py
index 6f93617..67ae89c 100644
--- a/setup.py
+++ b/setup.py
@@ -1,14 +1,5 @@
 #!/usr/bin/env python
-import os
-import sys
-
-try:
-    from setuptools import setup
-except ImportError:
-    from distutils.core import setup
-
-pwd = os.path.dirname(__file__)
-
+from setuptools import setup
 from setuptools.command.test import test as TestCommand
 
 
@@ -19,12 +10,13 @@ class PyTest(TestCommand):
         self.test_suite = True
 
     def run_tests(self):
+        import sys
         import pytest
         sys.exit(pytest.main(['tests']))
 
 setup(
     name="amodem",
-    version="1.3",
+    version="1.4",
     description="Audio Modem Communication Library",
     author="Roman Zeyde",
     author_email="roman.zeyde@gmail.com",
diff --git a/tests/test_calib.py b/tests/test_calib.py
index 1848036..0265087 100644
--- a/tests/test_calib.py
+++ b/tests/test_calib.py
@@ -1,5 +1,6 @@
 from amodem import calib
 from amodem import config
+config = config.fastest()
 
 from io import BytesIO
 
diff --git a/tests/test_dsp.py b/tests/test_dsp.py
index e3145e7..c9a1989 100644
--- a/tests/test_dsp.py
+++ b/tests/test_dsp.py
@@ -2,8 +2,9 @@ import numpy as np
 from numpy.linalg import norm
 
 from amodem import dsp
-from amodem import config
 from amodem import sampling
+from amodem import config
+config = config.fastest()
 
 import random
 import itertools
diff --git a/tests/test_equalizer.py b/tests/test_equalizer.py
index b7148a3..d62a22b 100644
--- a/tests/test_equalizer.py
+++ b/tests/test_equalizer.py
@@ -3,9 +3,9 @@ from numpy.random import RandomState
 import numpy as np
 
 from amodem import dsp
-from amodem import config
 from amodem import equalizer
-
+from amodem import config
+config = config.fastest()
 
 def assert_approx(x, y, e=1e-12):
     assert norm(x - y) < e * norm(x)
diff --git a/tests/test_recv.py b/tests/test_recv.py
index 08a9f11..4f66cb8 100644
--- a/tests/test_recv.py
+++ b/tests/test_recv.py
@@ -1,10 +1,11 @@
 import numpy as np
 
-from amodem import config
 from amodem import dsp
 from amodem import recv
 from amodem import train
 from amodem import sampling
+from amodem import config
+config = config.fastest()
 
 
 def test_detect():
diff --git a/tests/test_whole.py b/tests/test_whole.py
index 02bc7aa..15eee9e 100644
--- a/tests/test_whole.py
+++ b/tests/test_whole.py
@@ -9,6 +9,7 @@ from amodem import common
 from amodem import dsp
 from amodem import sampling
 from amodem import config
+config = config.fastest()
 
 import logging
 logging.basicConfig(level=logging.DEBUG,