Adding method IsInBeam to beamformer class.

webrtc/modules/audio_processing/beamformer/nonlinear_beamformer.cc

 /*
  *  Copyright (c) 2014 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.
  */
 
@@ skipping 32 matching lines @@
 // PI - |kInterfAngleRadians|. Since the beamformer is robust, this should
 // suppress sound coming from close angles as well.
 const float kInterfAngleRadians = static_cast<float>(M_PI) / 4.f;
 
 // When calculating the interference covariance matrix, this is the weight for
 // the weighted average between the uniform covariance matrix and the angled
 // covariance matrix.
 // Rpsi = Rpsi_angled * kBalance + Rpsi_uniform * (1 - kBalance)
 const float kBalance = 0.4f;
 
+// The width of half of the beam in radians.
+const float kBeamWidthAngle = static_cast<float>(M_PI)20.f / 180.f;

[aluebs-webrtc, 2015/06/25 01:04:36]

const float kBeamWidthAngle = static_cast<float>(M_PI) * 20.f / 180.f;

[Andrew MacDonald, 2015/06/26 02:04:24]

I think you can omit the cast.

[bloch, 2015/06/26 03:37:28]

I tried it without the cast and there were some compiler errors when I ran "git
cl try"

[Andrew MacDonald, 2015/06/26 03:46:09]

OK, thanks for trying.

+
 // TODO(claguna): need comment here.
 const float kBeamwidthConstant = 0.00002f;
 
 // Alpha coefficients for mask smoothing.
 const float kMaskTimeSmoothAlpha = 0.2f;
 const float kMaskFrequencySmoothAlpha = 0.6f;
 
 // The average mask is computed from masks in this mid-frequency range. If these
 // ranges are changed |kMaskQuantile| might need to be adjusted.
 const int kLowMeanStartHz = 200;
@@ skipping 264 matching lines @@
       // averaging).
       float sum = 0.f;
       for (int k = 0; k < input.num_channels(); ++k) {
         sum += input.channels(i)[k][j];
       }
       output->channels(i)[0][j] = sum / input.num_channels() * smoothed_mask;
     }
   }
 }
 
+bool NonlinearBeamformer::IsInBeam(float azimuth) {
+  // If more than half-beamwidth degrees away from the beam's center,
+  // you are out of the beam.
+  return fabs(azimuth - kTargetAngleRadians) < kBeamWidthAngle;
+}
+
 void NonlinearBeamformer::ProcessAudioBlock(const complex_f* const* input,
                                             int num_input_channels,
                                             int num_freq_bins,
                                             int num_output_channels,
                                             complex_f* const* output) {
   CHECK_EQ(num_freq_bins, kNumFreqBins);
   CHECK_EQ(num_input_channels, num_input_channels_);
   CHECK_EQ(num_output_channels, 1);
 
   // Calculating the post-filter masks. Note that we need two for each
@@ skipping 147 matching lines @@
                    new_mask_ + high_mean_end_bin_ + 1);
   if (new_mask_[quantile] > kMaskTargetThreshold) {
     is_target_present_ = true;
     interference_blocks_count_ = 0;
   } else {
     is_target_present_ = interference_blocks_count_++ < hold_target_blocks_;
   }
 }
 
 }  // namespace webrtc