Some further minor bitexact APM echo suppressor refactoring (#3)

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 414 matching lines @@
         (aec->sd[i] * aec->se[i] + 1e-10f);
     cohxd[i] =
         (aec->sxd[i][0] * aec->sxd[i][0] + aec->sxd[i][1] * aec->sxd[i][1]) /
         (aec->sx[i] * aec->sd[i] + 1e-10f);
   }
 }
 
 static void GetHighbandGain(const float* lambda, float* nlpGainHband) {
   int i;
 
-  nlpGainHband[0] = (float)0.0;
+  *nlpGainHband = (float)0.0;
   for (i = freqAvgIc; i < PART_LEN1 - 1; i++) {
-    nlpGainHband[0] += lambda[i];
+    *nlpGainHband += lambda[i];
   }
-  nlpGainHband[0] /= (float)(PART_LEN1 - 1 - freqAvgIc);
+  *nlpGainHband /= (float)(PART_LEN1 - 1 - freqAvgIc);
 }
 
 static void ComfortNoise(AecCore* aec,
                          float efw[2][PART_LEN1],
                          complex_t* comfortNoiseHband,
                          const float* noisePow,
                          const float* lambda) {
   int i, num;
   float rand[PART_LEN];
   float noise, noiseAvg, tmp, tmpAvg;
@@ skipping 555 matching lines @@
 
 static void EchoSuppression(AecCore* aec,
                             float* echo_subtractor_output,
                             float* output,
                             float* const* outputH) {
   float efw[2][PART_LEN1];
   float xfw[2][PART_LEN1];
   float dfw[2][PART_LEN1];
   complex_t comfortNoiseHband[PART_LEN1];
   float fft[PART_LEN2];
   float scale, dtmp;

[minyue-webrtc, 2015/12/04 09:54:48]

Is dtmp used anywhere? delete it if not

[hlundin-webrtc, 2015/12/04 10:49:08]

It looks like it is still used, but it can be made local to the scope where it
is used.

[peah-webrtc, 2015/12/04 23:05:57]

It is used. But is removed in one of the following CLs that makes it redundant.

[peah-webrtc, 2015/12/04 23:05:57]

True, but it will be removed later when that part is rewritten.

   float nlpGainHband;
   int i;
   size_t j;
 
   // Coherence and non-linear filter
   float cohde[PART_LEN1], cohxd[PART_LEN1];
   float hNlDeAvg, hNlXdAvg;
   float hNl[PART_LEN1];
   float hNlPref[kPrefBandSize];
   float hNlFb = 0, hNlFbLow = 0;
@@ skipping 24 matching lines @@
   // Windowed echo suppressor output ffts.
   WindowData(fft, aec->eBuf);
   aec_rdft_forward_128(fft);
   StoreAsComplex(fft, efw);
 
   aec->delayEstCtr++;
   if (aec->delayEstCtr == delayEstInterval) {
     aec->delayEstCtr = 0;
   }
 
-  // initialize comfort noise for H band
-  memset(comfortNoiseHband, 0, sizeof(comfortNoiseHband));
-  nlpGainHband = (float)0.0;
-  dtmp = (float)0.0;
-
   // We should always have at least one element stored in |far_buf|.
   assert(WebRtc_available_read(aec->far_buf_windowed) > 0);
   // NLP
   WebRtc_ReadBuffer(aec->far_buf_windowed, (void**)&xfw_ptr, &xfw[0][0], 1);
 
   // TODO(bjornv): Investigate if we can reuse |far_buf_windowed| instead of
   // |xfwBuf|.
   // Buffer far.
   memcpy(aec->xfwBuf, xfw_ptr, sizeof(float) * 2 * PART_LEN1);
 
@@ skipping 102 matching lines @@
   // Smooth the overdrive.
   if (aec->overDrive < aec->overDriveSm) {
     aec->overDriveSm = 0.99f * aec->overDriveSm + 0.01f * aec->overDrive;
   } else {
     aec->overDriveSm = 0.9f * aec->overDriveSm + 0.1f * aec->overDrive;
   }
 
   WebRtcAec_OverdriveAndSuppress(aec, hNl, hNlFb, efw);
 
   // Add comfort noise.
+  memset(comfortNoiseHband, 0, sizeof(comfortNoiseHband));
   WebRtcAec_ComfortNoise(aec, efw, comfortNoiseHband, aec->noisePow, hNl);
 
   // TODO(bjornv): Investigate how to take the windowing below into account if
   // needed.
   if (aec->metricsMode == 1) {
     // Note that we have a scaling by two in the time domain |eBuf|.
     // In addition the time domain signal is windowed before transformation,
     // losing half the energy on the average. We take care of the first
     // scaling only in UpdateMetrics().
     UpdateLevel(&aec->nlpoutlevel, efw);
@@ skipping 789 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;
 }