Avoiding overflow in cross correlation in NetEq.

webrtc/modules/audio_coding/neteq/expand.h

 /*
  *  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 102 matching lines @@
     int16_t voice_mix_factor; /* Q14 */
     int16_t current_voice_mix_factor; /* Q14 */
     AudioVector expand_vector0;
     AudioVector expand_vector1;
     bool onset;
     int mute_slope; /* Q20 */
   };
 
   // Calculate the auto-correlation of |input|, with length |input_length|
   // samples. The correlation is calculated from a downsampled version of
-  // |input|, and is written to |output|. The scale factor is written to
-  // |output_scale|.
+  // |input|, and is written to |output|.
   void Correlation(const int16_t* input,
                    size_t input_length,
-                   int16_t* output,
-                   int* output_scale) const;
+                   int16_t* output) const;
 
   void UpdateLagIndex();
 
   BackgroundNoise* const background_noise_;
   StatisticsCalculator* const statistics_;
   const size_t overlap_length_;
   size_t max_lag_;
   size_t expand_lags_[kNumLags];
   int lag_index_direction_;
   int current_lag_index_;
@@ skipping 11 matching lines @@
   virtual Expand* Create(BackgroundNoise* background_noise,
                          SyncBuffer* sync_buffer,
                          RandomVector* random_vector,
                          StatisticsCalculator* statistics,
                          int fs,
                          size_t num_channels) const;
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_EXPAND_H_