APM QA refactoring: render stream support, echo path simulation, new export engine

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

Index: webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/echo_path_simulation_factory.py
diff --git a/webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/echo_path_simulation_factory.py b/webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/echo_path_simulation_factory.py
new file mode 100644
index 0000000000000000000000000000000000000000..eeffd1d71b404fedb375ad4bfffaaaba8cd13243
--- /dev/null
+++ b/webrtc/modules/audio_processing/test/py_quality_assessment/quality_assessment/echo_path_simulation_factory.py
@@ -0,0 +1,48 @@
+# 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.
+
+"""Echo path simulation factory module.
+"""
+
+import numpy as np
+
+from . import echo_path_simulation
+
+
+class EchoPathSimulatorFactory(object):
+
+  # TODO(alessiob): Replace 5 ms delay (at 48 kHz sample rate) with a more
+  # realistic impulse response.
+  _LINEAR_ECHO_IMPULSE_RESPONSE = np.array([0.0]*(5 * 48) + [0.15])
+
+  def __init__(self):
+    pass
+
+  @classmethod
+  def GetInstance(cls, echo_path_simulator_class, render_input_filepath):
+    """Creates an EchoPathSimulator instance given a class object.
+
+    Args:
+      echo_path_simulator_class: EchoPathSimulator class object (not an
+                                 instance).
+      render_input_filepath: Path to the render audio track file.
+
+    Returns:
+      An EchoPathSimulator instance.
+    """
+    assert render_input_filepath is not None or (
+        echo_path_simulator_class == echo_path_simulation.NoEchoPathSimulator)
+
+    if echo_path_simulator_class == echo_path_simulation.NoEchoPathSimulator:
+      return echo_path_simulation.NoEchoPathSimulator()
+    elif echo_path_simulator_class == (
+        echo_path_simulation.LinearEchoPathSimulator):
+      return echo_path_simulation.LinearEchoPathSimulator(
+          render_input_filepath, cls._LINEAR_ECHO_IMPULSE_RESPONSE)
+    else:
+      return echo_path_simulator_class(render_input_filepath)