APM Quality Generator, noise generator and evaluation score workers factory + echo noise generator

webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/evaluation.py

Index: webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/evaluation.py
diff --git a/webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/evaluation.py b/webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/evaluation.py
index 78446a1e187bcd313de65e48c2a8ec4a18f3f38b..016690a2c4509b3fc95b1088dafe14adea9f6e7b 100644
--- a/webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/evaluation.py
+++ b/webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/evaluation.py
@@ -6,8 +6,12 @@
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
+"""Evaluator of the APM module.
+"""
+
 import logging
 
+
 class ApmModuleEvaluator(object):
 
   def __init__(self):
@@ -16,6 +20,10 @@ class ApmModuleEvaluator(object):
   @classmethod
   def run(cls, evaluation_score_workers, apm_output_filepath,
           reference_input_filepath, output_path):
+    """Runs the evaluation.
+
+    Iterates over the given evaluation score workers.
+    """
     # Init.
     scores = {}