Make the nonlinear beamformer steerable

webrtc/modules/audio_processing/beamformer/nonlinear_beamformer_unittest.cc

+/*
+ *  Copyright (c) 2015 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.
+ */
+
+// MSVC++ requires this to be set before any other includes to get M_PI.
+#define _USE_MATH_DEFINES
+
+#include "webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.h"
+
+#include <math.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace webrtc {
+namespace {
+
+const int kChunkSizeMs = 10;
+const int kSampleRateHz = 16000;
+
+SphericalPointf AzimuthToSphericalPoint(float azimuth_radians) {
+  return SphericalPointf(azimuth_radians, 0.f, 1.f);
+}
+
+void Verify(NonlinearBeamformer* bf, float target_azimuth_radians) {
+  EXPECT_TRUE(bf->IsInBeam(AzimuthToSphericalPoint(target_azimuth_radians)));
+  EXPECT_TRUE(bf->IsInBeam(AzimuthToSphericalPoint(
+      target_azimuth_radians - NonlinearBeamformer::kHalfBeamWidthRadians +
+      0.001f)));
+  EXPECT_TRUE(bf->IsInBeam(AzimuthToSphericalPoint(
+      target_azimuth_radians + NonlinearBeamformer::kHalfBeamWidthRadians -
+      0.001f)));
+  EXPECT_FALSE(bf->IsInBeam(AzimuthToSphericalPoint(
+      target_azimuth_radians - NonlinearBeamformer::kHalfBeamWidthRadians -
+      0.001f)));
+  EXPECT_FALSE(bf->IsInBeam(AzimuthToSphericalPoint(
+      target_azimuth_radians + NonlinearBeamformer::kHalfBeamWidthRadians +
+      0.001f)));
+}
+
+void AimAndVerify(NonlinearBeamformer* bf, float target_azimuth_radians) {
+  bf->AimAt(AzimuthToSphericalPoint(target_azimuth_radians));
+  Verify(bf, target_azimuth_radians);
+}
+
+}  // namespace
+
+TEST(NonlinearBeamformerTest, AimingModifiesBeam) {
+  std::vector<Point> array_geometry;
+  array_geometry.push_back(Point(-0.025f, 0.f, 0.f));
+  array_geometry.push_back(Point(0.025f, 0.f, 0.f));
+  NonlinearBeamformer bf(array_geometry);
+  bf.Initialize(kChunkSizeMs, kSampleRateHz);
+  // The default constructor parameter sets the target angle to PI / 2.
+  Verify(&bf, static_cast<float>(M_PI) / 2.f);
+  AimAndVerify(&bf, static_cast<float>(M_PI) / 3.f);
+  AimAndVerify(&bf, 3.f * static_cast<float>(M_PI) / 4.f);
+  AimAndVerify(&bf, static_cast<float>(M_PI) / 6.f);
+  AimAndVerify(&bf, static_cast<float>(M_PI));
+}
+
+TEST(NonlinearBeamformerTest, InterfAnglesTakeAmbiguityIntoAccount) {
+  {
+    // For linear arrays there is ambiguity.
+    std::vector<Point> array_geometry;
+    array_geometry.push_back(Point(-0.1f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.2f, 0.f, 0.f));
+    NonlinearBeamformer bf(array_geometry);
+    bf.Initialize(kChunkSizeMs, kSampleRateHz);
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(M_PI / 2.f - bf.away_radians_,
+                    bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(M_PI / 2.f + bf.away_radians_,
+                    bf.interf_angles_radians_[1]);
+    bf.AimAt(AzimuthToSphericalPoint(bf.away_radians_ / 2.f));
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(M_PI - bf.away_radians_ / 2.f,
+                    bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(3.f * bf.away_radians_ / 2.f, bf.interf_angles_radians_[1]);
+  }
+  {
+    // For planar arrays with normal in the xy-plane there is ambiguity.
+    std::vector<Point> array_geometry;
+    array_geometry.push_back(Point(-0.1f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.2f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.1f, 0.f, 0.2f));
+    array_geometry.push_back(Point(0.f, 0.f, -0.1f));
+    NonlinearBeamformer bf(array_geometry);
+    bf.Initialize(kChunkSizeMs, kSampleRateHz);
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(M_PI / 2.f - bf.away_radians_,
+                    bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(M_PI / 2.f + bf.away_radians_,
+                    bf.interf_angles_radians_[1]);
+    bf.AimAt(AzimuthToSphericalPoint(bf.away_radians_ / 2.f));
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(M_PI - bf.away_radians_ / 2.f,
+                    bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(3.f * bf.away_radians_ / 2.f, bf.interf_angles_radians_[1]);
+  }
+  {
+    // For planar arrays with normal not in the xy-plane there is no ambiguity.
+    std::vector<Point> array_geometry;
+    array_geometry.push_back(Point(0.f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.2f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.f, 0.1f, -0.2f));
+    NonlinearBeamformer bf(array_geometry);
+    bf.Initialize(kChunkSizeMs, kSampleRateHz);
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(M_PI / 2.f - bf.away_radians_,
+                    bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(M_PI / 2.f + bf.away_radians_,
+                    bf.interf_angles_radians_[1]);
+    bf.AimAt(AzimuthToSphericalPoint(bf.away_radians_ / 2.f));
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(-bf.away_radians_ / 2.f, bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(3.f * bf.away_radians_ / 2.f, bf.interf_angles_radians_[1]);
+  }
+  {
+    // For arrays which are not linear or planar there is no ambiguity.
+    std::vector<Point> array_geometry;
+    array_geometry.push_back(Point(0.f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.1f, 0.f, 0.f));
+    array_geometry.push_back(Point(0.f, 0.2f, 0.f));
+    array_geometry.push_back(Point(0.f, 0.f, 0.3f));
+    NonlinearBeamformer bf(array_geometry);
+    bf.Initialize(kChunkSizeMs, kSampleRateHz);
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(M_PI / 2.f - bf.away_radians_,
+                    bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(M_PI / 2.f + bf.away_radians_,
+                    bf.interf_angles_radians_[1]);
+    bf.AimAt(AzimuthToSphericalPoint(bf.away_radians_ / 2.f));
+    EXPECT_EQ(2u, bf.interf_angles_radians_.size());
+    EXPECT_FLOAT_EQ(-bf.away_radians_ / 2.f, bf.interf_angles_radians_[0]);
+    EXPECT_FLOAT_EQ(3.f * bf.away_radians_ / 2.f, bf.interf_angles_radians_[1]);
+  }
+}
+
+}  // namespace webrtc