audioproc_f with simulated mic analog gain

webrtc/modules/audio_processing/test/fake_recording_device_unittest.cc

+/*
+ *  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.
+ */
+
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "webrtc/base/array_view.h"
+#include "webrtc/modules/audio_processing/test/fake_recording_device.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+namespace {
+
+using MappingKind = FakeRecordingDevice::LevelToScalingMappingKind;
+
+// TODO(...): Add new mapping kinds here as they are added to
+// LevelToScalingMappingKind.
+const std::vector<MappingKind> kMappingKindsToTest =
+    {MappingKind::kIdentity, MappingKind::kLinear};
+
+const std::vector<std::vector<float>> kTestMultiChannelSamples{
+    std::vector<float>{-10.0, -1.0, -0.1, 0.0, 0.1, 1.0, 10.0}};
+
+// Returns a vector of ArrayView items of const floats.
+std::vector<rtc::ArrayView<const float>> VecVecToVecArrayViewOfConst(
+    const std::vector<std::vector<float>>& vectorOfVectors) {
+  std::vector<rtc::ArrayView<const float>> vectorOfArrayViews;
+  for (const auto& v : vectorOfVectors) { vectorOfArrayViews.emplace_back(v); }
+  return vectorOfArrayViews;
+}
+
+// Returns a vector of ArrayView items of non-const floats.
+std::vector<rtc::ArrayView<float>> VecVecToVecArrayView(
+    std::vector<std::vector<float>>* vectorOfVectors) {
+  std::vector<rtc::ArrayView<float>> vectorOfArrayViews;
+  for (auto& v : *vectorOfVectors) { vectorOfArrayViews.emplace_back(v); }
+  return vectorOfArrayViews;
+}
+
+// Checks that the samples modified using monotonic level values are also
+// monotonic.
+void CheckIfMonotoneSamplesModules(
+    const std::vector<rtc::ArrayView<float>>& prev,
+    const std::vector<rtc::ArrayView<float>>& curr) {
+  bool valid = true;
+  for (size_t i = 0; i < prev.size(); ++i) {
+    for (size_t j = 0; j < prev[i].size(); ++j) {
+      valid = std::fabs(prev[i][j]) <= std::fabs(curr[i][j]);
+      if (!valid) { break; }
+    }
+    if (!valid) { break; }
+  }
+  EXPECT_TRUE(valid);
+}
+
+// Checks that the samples in each pair have the same sign unless the sample in
+// |dst| is zero (because of zero gain).
+void CheckSameSign(
+    const std::vector<rtc::ArrayView<const float>>& src,
+    const std::vector<rtc::ArrayView<float>>& dst) {
+  const auto fsgn = [](float x) { return ((x < 0) ? -1 : (x > 0) ? 1 : 0); };
+  bool valid = true;
+  for (size_t i = 0; i < src.size(); ++i) {
+    for (size_t j = 0; j < src[i].size(); ++j) {
+      valid = dst[i][j] == 0.0f || fsgn(src[i][j]) == fsgn(dst[i][j]);
+      if (!valid) { break; }
+    }
+    if (!valid) { break; }
+  }
+  EXPECT_TRUE(valid);
+}
+
+std::string MappingKindToString(MappingKind kind) {
+  std::ostringstream ss;
+  ss << "simulated microphone kind code: " << static_cast<size_t>(kind);
+  return ss.str();
+}
+
+std::string AnalogLevelToString(int level) {
+  std::ostringstream ss;
+  ss << "analog level: " << level;
+  return ss.str();
+}
+
+}  // namespace
+
+TEST(AnalogVolumeMapper, CheckHelperFunctions) {
+  // Check read.
+  const auto src_multichannel_samples_view = VecVecToVecArrayViewOfConst(
+      kTestMultiChannelSamples);
+  EXPECT_EQ(kTestMultiChannelSamples[0][0],
+            src_multichannel_samples_view[0][0]);
+
+  // Check sizes.
+  auto dst_multichannel_samples = kTestMultiChannelSamples;
+  auto dst_multichannel_samples_view = VecVecToVecArrayView(
+      &dst_multichannel_samples);
+  EXPECT_EQ(kTestMultiChannelSamples.size(),  // Same number of channels.
+            dst_multichannel_samples_view.size());
+  EXPECT_EQ(kTestMultiChannelSamples[0].size(),  // Same number of samples.
+            dst_multichannel_samples_view[0].size());
+
+  // Check write.
+  dst_multichannel_samples[0][1] = -5.0f;
+  EXPECT_EQ(dst_multichannel_samples[0][0],
+            dst_multichannel_samples_view[0][0]);
+}
+
+TEST(AnalogVolumeMapper, GainCurveShouldBeMonotone) {
+  // Create test samples.
+  const auto src_multichannel_samples_view = VecVecToVecArrayViewOfConst(
+      kTestMultiChannelSamples);
+
+  // Create output buffers.
+  auto dst_multichannel_samples_prev = kTestMultiChannelSamples;
+  auto dst_multichannel_samples_prev_view = VecVecToVecArrayView(
+      &dst_multichannel_samples_prev);
+  auto dst_multichannel_samples = kTestMultiChannelSamples;
+  auto dst_multichannel_samples_view = VecVecToVecArrayView(
+      &dst_multichannel_samples);
+
+  // Test different mappings.
+  for (const auto& kind : kMappingKindsToTest) {
+    SCOPED_TRACE(MappingKindToString(kind));
+    webrtc::FakeRecordingDevice level_mapper(kind);
+
+    // Apply lowest analog level.
+    level_mapper.SimulateAnalogGain(
+        src_multichannel_samples_view, dst_multichannel_samples_prev_view, 0);
+
+    // Increment analog level to check monotonicity.
+    for (int i = 1; i <= 255; ++i) {
+      SCOPED_TRACE(AnalogLevelToString(i));
+      level_mapper.SimulateAnalogGain(
+          src_multichannel_samples_view, dst_multichannel_samples_view, i);
+      // TODO(alessiob): The test below is designed for state-less recording
+      // devices. If, for instance, soft-clipping is used, the test might need
+      // to be redesigned.
+      CheckIfMonotoneSamplesModules(
+          dst_multichannel_samples_prev_view, dst_multichannel_samples_view);
+
+      // Update prev.
+      dst_multichannel_samples_prev = dst_multichannel_samples;
+      dst_multichannel_samples_prev_view = VecVecToVecArrayView(
+          &dst_multichannel_samples_prev);
+    }
+  }
+}
+
+TEST(AnalogVolumeMapper, GainCurveShouldNotChangeSign) {
+  // Create test samples.
+  const auto src_multichannel_samples_view = VecVecToVecArrayViewOfConst(
+      kTestMultiChannelSamples);
+
+  // Create output buffer.
+  auto dst_multichannel_samples = kTestMultiChannelSamples;
+  auto dst_multichannel_samples_view = VecVecToVecArrayView(
+      &dst_multichannel_samples);
+
+  // Test different mappings.
+  for (const auto& kind : kMappingKindsToTest) {
+    SCOPED_TRACE(MappingKindToString(kind));
+    webrtc::FakeRecordingDevice level_mapper(kind);
+
+    for (int i = 0; i <= 255; ++i) {
+      SCOPED_TRACE(AnalogLevelToString(i));
+      level_mapper.SimulateAnalogGain(
+          src_multichannel_samples_view, dst_multichannel_samples_view, i);
+      // TODO(alessiob): The test below is designed for state-less recording
+      // devices. If, for instance, soft-clipping is used, the test might need
+      // to be redesigned.
+      CheckSameSign(
+          src_multichannel_samples_view, dst_multichannel_samples_view);
+    }
+  }
+}
+
+}  // namespace webrtc