Ducking fix #1:Initial refactoring preparing for further AEC work (changes are bitexact).

webrtc/modules/audio_processing/aec/aec_core.c

 /*
  *  Copyright (c) 2012 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 157 matching lines @@
                         aec->wfBuf[0][pos + j],
                         aec->wfBuf[1][pos + j]);
       yf[1][j] += MulIm(aec->xfBuf[0][xPos + j],
                         aec->xfBuf[1][xPos + j],
                         aec->wfBuf[0][pos + j],
                         aec->wfBuf[1][pos + j]);
     }
   }
 }
 
-static void ScaleErrorSignal(AecCore* aec, float ef[2][PART_LEN1]) {
-  const float mu = aec->extended_filter_enabled ? kExtendedMu : aec->normal_mu;
-  const float error_threshold = aec->extended_filter_enabled
+static void ScaleErrorSignal(int extended_filter_enabled,
+                             float normal_mu,
+                             float normal_error_threshold,
+                             float *x_pow,
+                             float ef[2][PART_LEN1]) {
+  const float mu = extended_filter_enabled ? kExtendedMu : normal_mu;
+  const float error_threshold = extended_filter_enabled
                                     ? kExtendedErrorThreshold
-                                    : aec->normal_error_threshold;
+                                    : normal_error_threshold;
   int i;
   float abs_ef;
   for (i = 0; i < (PART_LEN1); i++) {
-    ef[0][i] /= (aec->xPow[i] + 1e-10f);
-    ef[1][i] /= (aec->xPow[i] + 1e-10f);
+    ef[0][i] /= (x_pow[i] + 1e-10f);
+    ef[1][i] /= (x_pow[i] + 1e-10f);
     abs_ef = sqrtf(ef[0][i] * ef[0][i] + ef[1][i] * ef[1][i]);
 
     if (abs_ef > error_threshold) {
       abs_ef = error_threshold / (abs_ef + 1e-10f);
       ef[0][i] *= abs_ef;
       ef[1][i] *= abs_ef;
     }
 
     // Stepsize factor
     ef[0][i] *= mu;
@@ skipping 632 matching lines @@
         self->num_delay_values;
   }
 
   // Reset histogram.
   memset(self->delay_histogram, 0, sizeof(self->delay_histogram));
   self->num_delay_values = 0;
 
   return;
 }
 
+static void FrequencyToTime(float freq_data[2][PART_LEN1],
+                            float time_data[PART_LEN2]) {
+  int i;
+  time_data[0] = freq_data[0][0];
+  time_data[1] = freq_data[0][PART_LEN];
+  for (i = 1; i < PART_LEN; i++) {
+    time_data[2 * i] = freq_data[0][i];
+    time_data[2 * i + 1] = freq_data[1][i];
+  }
+  aec_rdft_inverse_128(time_data);
+}
+
+
 static void TimeToFrequency(float time_data[PART_LEN2],
                             float freq_data[2][PART_LEN1],
                             int window) {
   int i = 0;
 
   // TODO(bjornv): Should we have a different function/wrapper for windowed FFT?
   if (window) {
     for (i = 0; i < PART_LEN; i++) {
       time_data[i] *= WebRtcAec_sqrtHanning[i];
       time_data[PART_LEN + i] *= WebRtcAec_sqrtHanning[PART_LEN - i];
@@ skipping 85 matching lines @@
     float delay_quality = WebRtc_last_delay_quality(self->delay_estimator);
     delay_quality = (delay_quality > kDelayQualityThresholdMax ?
         kDelayQualityThresholdMax : delay_quality);
     self->delay_quality_threshold =
         (delay_quality > self->delay_quality_threshold ? delay_quality :
             self->delay_quality_threshold);
   }
   return delay_correction;
 }
 
-static void NonLinearProcessing(AecCore* aec,
-                                float* output,
-                                float* const* outputH) {
+static void EchoSubtraction(AecCore* aec,
+                            float* nearend_ptr) {
+  float yf[2][PART_LEN1];
+  float fft[PART_LEN2];
+  float y[PART_LEN];
+  float e[PART_LEN];
+  float ef[2][PART_LEN1];
+  float scale;
+  int i;
+  memset(yf, 0, sizeof(yf));
+
+  // Produce frequency domain echo estimate.
+  WebRtcAec_FilterFar(aec, yf);
+
+  // Inverse fft to obtain echo estimate and error.
+  FrequencyToTime(yf, fft);
+
+  // Extract the output signal and compute the time-domain error.
+  scale = 2.0f / PART_LEN2;
+  for (i = 0; i < PART_LEN; ++i) {
+    y[i] = fft[PART_LEN + i] * scale;  // fft scaling.
+    e[i] = nearend_ptr[i] - y[i];
+  }
+
+  // Error fft
+  memcpy(aec->eBuf + PART_LEN, e, sizeof(float) * PART_LEN);
+  memset(fft, 0, sizeof(float) * PART_LEN);
+  memcpy(fft + PART_LEN, e, sizeof(float) * PART_LEN);
+  TimeToFrequency(fft, ef, 0);
+
+  RTC_AEC_DEBUG_RAW_WRITE(aec->e_fft_file,
+                          &ef[0][0],
+                          sizeof(ef[0][0]) * PART_LEN1 * 2);
+
+  if (aec->metricsMode == 1) {
+    // Note that the first PART_LEN samples in fft (before transformation) are
+    // zero. Hence, the scaling by two in UpdateLevel() should not be
+    // performed. That scaling is taken care of in UpdateMetrics() instead.
+    UpdateLevel(&aec->linoutlevel, ef);
+  }
+
+  // Scale error signal inversely with far power.
+  WebRtcAec_ScaleErrorSignal(aec->extended_filter_enabled,
+                             aec->normal_mu,
+                             aec->normal_error_threshold,
+                             aec->xPow,
+                             ef);
+  WebRtcAec_FilterAdaptation(aec, fft, ef);
+
+
+  RTC_AEC_DEBUG_WAV_WRITE(aec->outLinearFile, e, PART_LEN);
+}
+
+
+static void EchoSuppression(AecCore* aec,
+                            float* output,
+                            float* const* outputH) {
   float efw[2][PART_LEN1], xfw[2][PART_LEN1];
   complex_t comfortNoiseHband[PART_LEN1];
   float fft[PART_LEN2];
   float scale, dtmp;
   float nlpGainHband;
   int i;
   size_t j;
 
   // Coherence and non-linear filter
   float cohde[PART_LEN1], cohxd[PART_LEN1];
@@ skipping 212 matching lines @@
     memcpy(aec->dBufH[j], aec->dBufH[j] + PART_LEN, sizeof(float) * PART_LEN);
   }
 
   memmove(aec->xfwBuf + PART_LEN1,
           aec->xfwBuf,
           sizeof(aec->xfwBuf) - sizeof(complex_t) * PART_LEN1);
 }
 
 static void ProcessBlock(AecCore* aec) {
   size_t i;
-  float y[PART_LEN], e[PART_LEN];
-  float scale;
 
   float fft[PART_LEN2];
-  float xf[2][PART_LEN1], yf[2][PART_LEN1], ef[2][PART_LEN1];
+  float xf[2][PART_LEN1];
   float df[2][PART_LEN1];
   float far_spectrum = 0.0f;
   float near_spectrum = 0.0f;
   float abs_far_spectrum[PART_LEN1];
   float abs_near_spectrum[PART_LEN1];
 
   const float gPow[2] = {0.9f, 0.1f};
 
   // Noise estimate constants.
   const int noiseInitBlocks = 500 * aec->mult;
   const float step = 0.1f;
   const float ramp = 1.0002f;
   const float gInitNoise[2] = {0.999f, 0.001f};
 
   float nearend[PART_LEN];
   float* nearend_ptr = NULL;
   float output[PART_LEN];
   float outputH[NUM_HIGH_BANDS_MAX][PART_LEN];
   float* outputH_ptr[NUM_HIGH_BANDS_MAX];
+  float* xf_ptr = NULL;
+
   for (i = 0; i < NUM_HIGH_BANDS_MAX; ++i) {
     outputH_ptr[i] = outputH[i];
   }
 
-  float* xf_ptr = NULL;
-
   // Concatenate old and new nearend blocks.
   for (i = 0; i < aec->num_bands - 1; ++i) {
     WebRtc_ReadBuffer(aec->nearFrBufH[i],
                       (void**)&nearend_ptr,
                       nearend,
                       PART_LEN);
     memcpy(aec->dBufH[i] + PART_LEN, nearend_ptr, sizeof(nearend));
   }
   WebRtc_ReadBuffer(aec->nearFrBuf, (void**)&nearend_ptr, nearend, PART_LEN);
   memcpy(aec->dBuf + PART_LEN, nearend_ptr, sizeof(nearend));
@@ skipping 87 matching lines @@
   }
 
   // Buffer xf
   memcpy(aec->xfBuf[0] + aec->xfBufBlockPos * PART_LEN1,
          xf_ptr,
          sizeof(float) * PART_LEN1);
   memcpy(aec->xfBuf[1] + aec->xfBufBlockPos * PART_LEN1,
          &xf_ptr[PART_LEN1],
          sizeof(float) * PART_LEN1);
 
-  memset(yf, 0, sizeof(yf));
+  // Perform echo subtraction.
+  EchoSubtraction(aec, nearend_ptr);
 
-  // Filter far
-  WebRtcAec_FilterFar(aec, yf);
-
-  // Inverse fft to obtain echo estimate and error.
-  fft[0] = yf[0][0];
-  fft[1] = yf[0][PART_LEN];
-  for (i = 1; i < PART_LEN; i++) {
-    fft[2 * i] = yf[0][i];
-    fft[2 * i + 1] = yf[1][i];
-  }
-  aec_rdft_inverse_128(fft);
-
-  scale = 2.0f / PART_LEN2;
-  for (i = 0; i < PART_LEN; i++) {
-    y[i] = fft[PART_LEN + i] * scale;  // fft scaling
-  }
-
-  for (i = 0; i < PART_LEN; i++) {
-    e[i] = nearend_ptr[i] - y[i];
-  }
-
-  // Error fft
-  memcpy(aec->eBuf + PART_LEN, e, sizeof(float) * PART_LEN);
-  memset(fft, 0, sizeof(float) * PART_LEN);
-  memcpy(fft + PART_LEN, e, sizeof(float) * PART_LEN);
-  // TODO(bjornv): Change to use TimeToFrequency().
-  aec_rdft_forward_128(fft);
-
-  ef[1][0] = 0;
-  ef[1][PART_LEN] = 0;
-  ef[0][0] = fft[0];
-  ef[0][PART_LEN] = fft[1];
-  for (i = 1; i < PART_LEN; i++) {
-    ef[0][i] = fft[2 * i];
-    ef[1][i] = fft[2 * i + 1];
-  }
-
-  RTC_AEC_DEBUG_RAW_WRITE(aec->e_fft_file,
-                          &ef[0][0],
-                          sizeof(ef[0][0]) * PART_LEN1 * 2);
-
-  if (aec->metricsMode == 1) {
-    // Note that the first PART_LEN samples in fft (before transformation) are
-    // zero. Hence, the scaling by two in UpdateLevel() should not be
-    // performed. That scaling is taken care of in UpdateMetrics() instead.
-    UpdateLevel(&aec->linoutlevel, ef);
-  }
-
-  // Scale error signal inversely with far power.
-  WebRtcAec_ScaleErrorSignal(aec, ef);
-  WebRtcAec_FilterAdaptation(aec, fft, ef);
-  NonLinearProcessing(aec, output, outputH_ptr);
+  // Perform echo suppression.
+  EchoSuppression(aec, output, outputH_ptr);
 
   if (aec->metricsMode == 1) {
     // Update power levels and echo metrics
     UpdateLevel(&aec->farlevel, (float(*)[PART_LEN1])xf_ptr);
     UpdateLevel(&aec->nearlevel, df);
     UpdateMetrics(aec);
   }
 
   // Store the output block.
   WebRtc_WriteBuffer(aec->outFrBuf, output, PART_LEN);
   // For high bands
   for (i = 0; i < aec->num_bands - 1; ++i) {
     WebRtc_WriteBuffer(aec->outFrBufH[i], outputH[i], PART_LEN);
   }
 
-  RTC_AEC_DEBUG_WAV_WRITE(aec->outLinearFile, e, PART_LEN);
   RTC_AEC_DEBUG_WAV_WRITE(aec->outFile, output, PART_LEN);
 }
 
 AecCore* WebRtcAec_CreateAec() {
   int i;
   AecCore* aec = malloc(sizeof(AecCore));
   if (!aec) {
     return NULL;
   }
 
@@ skipping 523 matching lines @@
 int WebRtcAec_extended_filter_enabled(AecCore* self) {
   return self->extended_filter_enabled;
 }
 
 int WebRtcAec_system_delay(AecCore* self) { return self->system_delay; }
 
 void WebRtcAec_SetSystemDelay(AecCore* self, int delay) {
   assert(delay >= 0);
   self->system_delay = delay;
 }