Total Harmonic Distorsion plus noise (THD+n) score in APM-QA.

modules/audio_processing/test/py_quality_assessment/quality_assessment/input_signal_creator.py

 # Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 """Input signal creator module.
 """
 
 from . import exceptions
 from . import signal_processing
 
 
 class InputSignalCreator(object):
   """Input signal creator class.
   """
 
   @classmethod
-  def Create(cls, name, params):
-    """Creates a input signal.
+  def Create(cls, name, raw_params):
+    """Creates a input signal and its metadata.
 
     Args:
       name: Input signal creator name.
-      params: Tuple of parameters to pass to the specific signal creator.
+      raw_params: Tuple of parameters to pass to the specific signal creator.
 
     Returns:
-      AudioSegment instance.
+      (AudioSegment, dict) tuple.
     """
     try:
+      signal = {}
+      params = {}
+
       if name == 'pure_tone':
-        return cls._CreatePureTone(float(params[0]), int(params[1]))
+        params['frequency'] = float(raw_params[0])
+        params['duration'] = int(raw_params[1])
+        signal = cls._CreatePureTone(params['frequency'], params['duration'])
+      else:
+        raise exceptions.InputSignalCreatorException(
+            'Invalid input signal creator name')
+
+      # Complete metadata.
+      params['signal'] = name
+
+      return signal, params
     except (TypeError, AssertionError) as e:
       raise exceptions.InputSignalCreatorException(
           'Invalid signal creator parameters: {}'.format(e))
 
-    raise exceptions.InputSignalCreatorException(
-        'Invalid input signal creator name')
-
   @classmethod
   def _CreatePureTone(cls, frequency, duration):
     """
     Generates a pure tone at 48000 Hz.
 
     Args:
       frequency: Float in (0-24000] (Hz).
       duration: Integer (milliseconds).
 
     Returns:
       AudioSegment instance.
     """
     assert 0 < frequency <= 24000
     assert 0 < duration
     template = signal_processing.SignalProcessingUtils.GenerateSilence(duration)
     return signal_processing.SignalProcessingUtils.GeneratePureTone(
         template, frequency)