audioproc_f with simulated mic analog gain

webrtc/modules/audio_processing/test/fake_recording_device.h

+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_TEST_FAKE_RECORDING_DEVICE_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_TEST_FAKE_RECORDING_DEVICE_H_
+
+#include <algorithm>
+#include <memory>
+#include <vector>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/base/checks.h"
+#include "webrtc/base/optional.h"
+#include "webrtc/common_audio/channel_buffer.h"
+#include "webrtc/modules/include/module_common_types.h"
+
+namespace webrtc {
+namespace test {
+
+class FakeRecordingDeviceWorker;

[AleBzk, 2017/06/22 10:16:01]

Forward declaration for the FakeRecordingDeviceWorker abstract class, which is
defined in audio_processing_simulator.cc. The same file also contains
FakeRecordingDeviceWorker implementations (in the anon ns).

+
+// Abstract class for simulating a microphone with analog gain.

[peah-webrtc, 2017/06/29 05:45:27]

This is not an abstract class, right? Or did I get it wrong?

[AleBzk, 2017/06/29 11:43:36]

Sorry, this comment applies to the previous PS, I forgot to update.

+//
+// The intended modes of operation are the following:
+//
+// auto fake_mic = FakeRecordingDevice(
+//     255, FakeRecordingDevice.DeviceKind.LINEAR);

[AleBzk, 2017/06/22 10:16:01]

I fixed this as follows:

// FakeRecordingDevice fake_mic(
//     255, FakeRecordingDevice.DeviceKind.LINEAR);

Will upload in the next PS once I get your comments.

+//
+// fake_mic.set_mic_level(170);
+// fake_mic.set_undo_mic_level(rtc::Optional<int>());
+// fake_mic.SimulateAnalogGain(buffer);
+//
+// When the mic level to undo is known:
+//
+// fake_mic.set_mic_level(170);
+// fake_mic.set_undo_mic_level(rtc::Optional<int>(30));
+// fake_mic.SimulateAnalogGain(buffer);
+//
+// The second option virtually restores the unmodified microphone level. Calling
+// SimulateAnalogGain() will first "undo" the gain applied by the real
+// microphone (e.g., 30).
+class FakeRecordingDevice final {
+ public:
+  enum class DeviceKind { IDENTITY, LINEAR };
+
+  FakeRecordingDevice(int initial_mic_level, DeviceKind kind);
+  ~FakeRecordingDevice();
+
+  // Setter and getter for the mic level to simulate.
+  void set_mic_level(int level) { mic_level_ = level; }
+  int mic_level() const { return mic_level_; }
+
+  // Setter and getter for the mic level to undo.
+  void set_undo_mic_level(rtc::Optional<int> level) { undo_mic_level_ = level; }
+  rtc::Optional<int> undo_mic_level() const { return undo_mic_level_; }
+
+  // Simulates the analog gain.
+  // If |real_device_level| is a valid level, the unmodified mic signal is
+  // virtually restored. To skip the latter step set |real_device_level| to
+  // an empty value.
+  void SimulateAnalogGain(ChannelBuffer<float>* buffer);
+
+  // Simulates the analog gain.
+  // If |real_device_level| is a valid level, the unmodified mic signal is
+  // virtually restored. To skip the latter step set |real_device_level| to
+  // an empty value.
+  void SimulateAnalogGain(AudioFrame* buffer);
+
+ private:
+  // Mic level to simulate.
+  int mic_level_;
+
+  // Fake recording device worker.
+  std::unique_ptr<FakeRecordingDeviceWorker> worker_;
+
+  // Optional undo mic level.
+  rtc::Optional<int> undo_mic_level_;
+};
+
+}  // namespace test
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_TEST_FAKE_RECORDING_DEVICE_H_