standardise program/sox.py formatting, add test case, docstring

.travis.yml

@@ -10,7 +10,7 @@ install:
  - sudo pip install musicbrainzngs pycdio
 
  # Testing dependencies
- - sudo apt-get install -qq gstreamer0.10-tools python-gst0.10
+ - sudo apt-get install -qq gstreamer0.10-tools python-gst0.10 sox
  - sudo pip install twisted
 
  # Build bundled C utils

morituri/program/sox.py

@@ -1,16 +1,24 @@
-import os
 import logging
+import os
 from subprocess import Popen, PIPE
 
 SOX = 'sox'
 
 def peak_level(track_path):
- if not os.path.exists(track_path):
- logging.warning("SoX peak detection failed: file not found")
- return None
- sox = Popen([SOX, track_path, "-n", "stat"], stderr=PIPE)
- out, err = sox.communicate()
- if sox.returncode:
- logging.warning("SoX peak detection failed: " + s.returncode)
- return None
- return float(err.split('\n')[3].split()[2]) # Maximum amplitude: 0.123456
+ """
+ Accepts a path to a sox-decodable audio file.
+
+ Returns track peak level from sox ('maximum amplitude') as a float.
+ Returns None on error.
+ """
+ if not os.path.exists(track_path):
+ logging.warning("SoX peak detection failed: file not found")
+ return None
+ sox = Popen([SOX, track_path, "-n", "stat"], stderr=PIPE)
+ out, err = sox.communicate()
+ if sox.returncode:
+ logging.warning("SoX peak detection failed: " + str(sox.returncode))
+ return None
+ # relevant captured line looks like:
+ # Maximum amplitude: 0.123456
+ return float(err.split('\n')[3].split()[2])

morituri/test/test_program_sox.py

@@ -0,0 +1,13 @@
+# -*- Mode: Python; test-case-name: morituri.test.test_program_sox -*-
+
+import os
+
+from morituri.program import sox
+from morituri.test import common
+
+class PeakLevelTestCase(common.TestCase):
+ def setUp(self):
+ self.path = os.path.join(os.path.dirname(__file__), 'track.flac')
+
+ def testParse(self):
+ self.assertEquals(0.800018, sox.peak_level(self.path))