Silan cue-in/out analysis now moved to airtime_analyzer

* Added a new CuePointAnalyzer using silan (will remove silan stuff from pypo later)
* Makes silan analysis slightly more reliable for certain short files.
* Fixes CC-5961: Audio duration cutoff for WAVE files
* Added unit tests for the new analyzer and improved code coverage slightly
* Added unit tests for WAVE metadata extraction and an invalid WMA file

python_apps/airtime_analyzer/airtime_analyzer/replaygain_analyzer.py

@@ -1,14 +1,41 @@
+import subprocess
 from analyzer import Analyzer
 
-''' TODO: ReplayGain is currently calculated by pypo but it should
-          be done here in the analyzer.
-'''
+
 class ReplayGainAnalyzer(Analyzer):
-    
+    ''' This class extracts the cue-in time, cue-out time, and length of a track using silan. '''
+
+    BG1770GAIN_EXECUTABLE = 'bg1770gain'
+
     def __init__(self):
         pass
-    
+
     @staticmethod
-    def analyze(filename):
-        pass
-    
+    def analyze(filename, metadata):
+        ''' Extracts the Replaygain loudness normalization factor of a track.
+        :param filename: The full path to the file to analyzer
+        :param metadata: A metadata dictionary where the results will be put
+        :return: The metadata dictionary
+        '''
+        ''' The -d 00:01:00 flag means it will let the decoding run for a maximum of 1 minute. This is a safeguard
+            in case the libavcodec decoder gets stuck in an infinite loop.
+        '''
+        command = [ReplayGainAnalyzer.BG1770GAIN_EXECUTABLE, '--replaygain', '-d', '00:01:00', '-f', 'JSON', filename]
+        try:
+            results_json = subprocess.check_output(command)
+            silan_results = json.loads(results_json)
+            metadata['length_seconds'] = float(silan_results['file duration'])
+            # Conver the length into a formatted time string
+            track_length = datetime.timedelta(seconds=metadata['length_seconds'])
+            metadata["length"] = str(track_length)
+            metadata['cuein'] = silan_results['sound'][0][0]
+            metadata['cueout'] = silan_results['sound'][0][1]
+
+        except OSError as e: # silan was not found
+            logging.warn("Failed to run: %s - %s. %s" % (command[0], e.strerror, "Do you have silan installed?"))
+        except subprocess.CalledProcessError as e: # silan returned an error code
+            logging.warn("%s %s %s", e.cmd, e.message, e.returncode)
+        except Exception as e:
+            logging.warn(e)
+
+        return metadata