Added a bitexactness test for the gain controller in the audio processing module.

BUG=webrtc:5339

Review URL: https://codereview.webrtc.org/1812433002

Cr-Commit-Position: refs/heads/master@{#12124}
diff --git a/webrtc/modules/audio_processing/gain_control_unittest.cc b/webrtc/modules/audio_processing/gain_control_unittest.cc
new file mode 100644
index 0000000..9436ffc
--- /dev/null
+++ b/webrtc/modules/audio_processing/gain_control_unittest.cc
@@ -0,0 +1,315 @@
+/*
+ *  Copyright (c) 2016 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.
+ */
+#include <vector>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/array_view.h"
+#include "webrtc/modules/audio_processing/audio_buffer.h"
+#include "webrtc/modules/audio_processing/gain_control_impl.h"
+#include "webrtc/modules/audio_processing/test/audio_buffer_tools.h"
+#include "webrtc/modules/audio_processing/test/bitexactness_tools.h"
+
+namespace webrtc {
+namespace {
+
+const int kNumFramesToProcess = 1000;
+
+void ProcessOneFrame(int sample_rate_hz,
+                     AudioBuffer* render_audio_buffer,
+                     AudioBuffer* capture_audio_buffer,
+                     GainControlImpl* gain_controller) {
+  if (sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
+    render_audio_buffer->SplitIntoFrequencyBands();
+    capture_audio_buffer->SplitIntoFrequencyBands();
+  }
+
+  gain_controller->ProcessRenderAudio(render_audio_buffer);
+  gain_controller->AnalyzeCaptureAudio(capture_audio_buffer);
+  gain_controller->ProcessCaptureAudio(capture_audio_buffer, false);
+
+  if (sample_rate_hz > AudioProcessing::kSampleRate16kHz) {
+    capture_audio_buffer->MergeFrequencyBands();
+  }
+}
+
+void SetupComponent(int sample_rate_hz,
+                    GainControl::Mode mode,
+                    int target_level_dbfs,
+                    int stream_analog_level,
+                    int compression_gain_db,
+                    bool enable_limiter,
+                    int analog_level_min,
+                    int analog_level_max,
+                    GainControlImpl* gain_controller) {
+  gain_controller->Initialize(1, sample_rate_hz);
+  GainControl* gc = static_cast<GainControl*>(gain_controller);
+  gc->Enable(true);
+  gc->set_mode(mode);
+  gc->set_stream_analog_level(stream_analog_level);
+  gc->set_target_level_dbfs(target_level_dbfs);
+  gc->set_compression_gain_db(compression_gain_db);
+  gc->enable_limiter(enable_limiter);
+  gc->set_analog_level_limits(analog_level_min, analog_level_max);
+}
+
+void RunBitExactnessTest(int sample_rate_hz,
+                         size_t num_channels,
+                         GainControl::Mode mode,
+                         int target_level_dbfs,
+                         int stream_analog_level,
+                         int compression_gain_db,
+                         bool enable_limiter,
+                         int analog_level_min,
+                         int analog_level_max,
+                         int achieved_stream_analog_level_reference,
+                         rtc::ArrayView<const float> output_reference) {
+  rtc::CriticalSection crit_render;
+  rtc::CriticalSection crit_capture;
+  GainControlImpl gain_controller(&crit_render, &crit_capture);
+  SetupComponent(sample_rate_hz, mode, target_level_dbfs, stream_analog_level,
+                 compression_gain_db, enable_limiter, analog_level_min,
+                 analog_level_max, &gain_controller);
+
+  const int samples_per_channel = rtc::CheckedDivExact(sample_rate_hz, 100);
+  const StreamConfig render_config(sample_rate_hz, num_channels, false);
+  AudioBuffer render_buffer(
+      render_config.num_frames(), render_config.num_channels(),
+      render_config.num_frames(), 1, render_config.num_frames());
+  test::InputAudioFile render_file(
+      test::GetApmRenderTestVectorFileName(sample_rate_hz));
+  std::vector<float> render_input(samples_per_channel * num_channels);
+
+  const StreamConfig capture_config(sample_rate_hz, num_channels, false);
+  AudioBuffer capture_buffer(
+      capture_config.num_frames(), capture_config.num_channels(),
+      capture_config.num_frames(), 1, capture_config.num_frames());
+  test::InputAudioFile capture_file(
+      test::GetApmCaptureTestVectorFileName(sample_rate_hz));
+  std::vector<float> capture_input(samples_per_channel * num_channels);
+
+  for (int frame_no = 0; frame_no < kNumFramesToProcess; ++frame_no) {
+    ReadFloatSamplesFromStereoFile(samples_per_channel, num_channels,
+                                   &render_file, render_input);
+    ReadFloatSamplesFromStereoFile(samples_per_channel, num_channels,
+                                   &capture_file, capture_input);
+
+    test::CopyVectorToAudioBuffer(render_config, render_input, &render_buffer);
+    test::CopyVectorToAudioBuffer(capture_config, capture_input,
+                                  &capture_buffer);
+
+    ProcessOneFrame(sample_rate_hz, &render_buffer, &capture_buffer,
+                    &gain_controller);
+  }
+
+  // Extract and verify the test results.
+  std::vector<float> capture_output;
+  test::ExtractVectorFromAudioBuffer(capture_config, &capture_buffer,
+                                     &capture_output);
+
+  EXPECT_EQ(achieved_stream_analog_level_reference,
+            gain_controller.stream_analog_level());
+
+  // Compare the output with the reference. Only the first values of the output
+  // from last frame processed are compared in order not having to specify all
+  // preceeding frames as testvectors. As the algorithm being tested has a
+  // memory, testing only the last frame implicitly also tests the preceeding
+  // frames.
+  const float kTolerance = 1.0f / 32768.0f;
+  EXPECT_TRUE(test::BitExactFrame(
+      capture_config.num_frames(), capture_config.num_channels(),
+      output_reference, capture_output, kTolerance));
+}
+
+}  // namespace
+
+TEST(GainControlBitExactnessTest,
+     Mono8kHz_AdaptiveAnalog_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.004578f, -0.003998f, -0.002991f};
+  RunBitExactnessTest(8000, 1, GainControl::Mode::kAdaptiveAnalog, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_AdaptiveAnalog_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.004303f, -0.004150f, -0.004089f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kAdaptiveAnalog, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Stereo16kHz_AdaptiveAnalog_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.010254f, -0.004761f, -0.009918f,
+                                    -0.010254f, -0.004761f, -0.009918f};
+  RunBitExactnessTest(16000, 2, GainControl::Mode::kAdaptiveAnalog, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono32kHz_AdaptiveAnalog_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.005554f, -0.005066f, -0.004242f};
+  RunBitExactnessTest(32000, 1, GainControl::Mode::kAdaptiveAnalog, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono48kHz_AdaptiveAnalog_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.005554f, -0.005066f, -0.004242f};
+  RunBitExactnessTest(32000, 1, GainControl::Mode::kAdaptiveAnalog, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono8kHz_AdaptiveDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.014221f, -0.012421f, -0.009308f};
+  RunBitExactnessTest(8000, 1, GainControl::Mode::kAdaptiveDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_AdaptiveDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.014923f, -0.014404f, -0.014191f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kAdaptiveDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Stereo16kHz_AdaptiveDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.009796f, -0.004547f, -0.009460f,
+                                    -0.009796f, -0.004547f, -0.009460f};
+  RunBitExactnessTest(16000, 2, GainControl::Mode::kAdaptiveDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono32kHz_AdaptiveDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.019287f, -0.017578f, -0.014709f};
+  RunBitExactnessTest(32000, 1, GainControl::Mode::kAdaptiveDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono48kHz_AdaptiveDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.019287f, -0.017578f, -0.014709f};
+  RunBitExactnessTest(32000, 1, GainControl::Mode::kAdaptiveDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono8kHz_FixedDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.008209f, -0.007172f, -0.005371f};
+  RunBitExactnessTest(8000, 1, GainControl::Mode::kFixedDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_FixedDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.007721f, -0.007446f, -0.007355f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kFixedDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Stereo16kHz_FixedDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.018402f, -0.008545f, -0.017792f,
+                                    -0.018402f, -0.008545f, -0.017792f};
+  RunBitExactnessTest(16000, 2, GainControl::Mode::kFixedDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono32kHz_FixedDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.009979f, -0.009064f, -0.007629f};
+  RunBitExactnessTest(32000, 1, GainControl::Mode::kFixedDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono48kHz_FixedDigital_Tl10_SL50_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 50;
+  const float kOutputReference[] = {-0.009979f, -0.009064f, -0.007629f};
+  RunBitExactnessTest(32000, 1, GainControl::Mode::kFixedDigital, 10, 50, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_AdaptiveAnalog_Tl10_SL10_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 12;
+  const float kOutputReference[] = {-0.004303f, -0.004150f, -0.004089f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kAdaptiveAnalog, 10, 10, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_AdaptiveAnalog_Tl10_SL100_CG5_Lim_AL70_80) {
+  const int kStreamAnalogLevelReference = 100;
+  const float kOutputReference[] = {-0.004303f, -0.004150f, -0.004089f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kAdaptiveAnalog, 10, 100, 5,
+                      true, 70, 80, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_AdaptiveDigital_Tl10_SL100_CG5_NoLim_AL0_100) {
+  const int kStreamAnalogLevelReference = 100;
+  const float kOutputReference[] = {-0.014923f, -0.014404f, -0.014191f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kAdaptiveDigital, 10, 100, 5,
+                      false, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_AdaptiveDigital_Tl40_SL100_CG5_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 100;
+  const float kOutputReference[] = {-0.020721f, -0.019989f, -0.019714f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kAdaptiveDigital, 40, 100, 5,
+                      true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+TEST(GainControlBitExactnessTest,
+     Mono16kHz_AdaptiveDigital_Tl10_SL100_CG30_Lim_AL0_100) {
+  const int kStreamAnalogLevelReference = 100;
+  const float kOutputReference[] = {-0.020416f, -0.019714f, -0.019409f};
+  RunBitExactnessTest(16000, 1, GainControl::Mode::kAdaptiveDigital, 10, 100,
+                      30, true, 0, 100, kStreamAnalogLevelReference,
+                      kOutputReference);
+}
+
+}  // namespace webrtc
diff --git a/webrtc/modules/modules.gyp b/webrtc/modules/modules.gyp
index 492b618..51c1c4e 100644
--- a/webrtc/modules/modules.gyp
+++ b/webrtc/modules/modules.gyp
@@ -444,6 +444,7 @@
                 'audio_processing/audio_processing_impl_locking_unittest.cc',
                 'audio_processing/audio_processing_impl_unittest.cc',
                 'audio_processing/echo_control_mobile_unittest.cc',
+                'audio_processing/gain_control_unittest.cc',
                 'audio_processing/high_pass_filter_bitexactness_unittest.cc',
                 'audio_processing/level_estimator_bitexactness_unittest.cc',
                 'audio_processing/noise_suppression_bitexactness_unittest.cc',