Revert of Avoiding overflow in cross correlation in NetEq.

webrtc/modules/audio_coding/neteq/cross_correlation.h

-/*
- *  Copyright (c) 2016 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.
- */
-
-#ifndef WEBRTC_MODULES_AUDIO_CODING_NETEQ_CROSS_CORRELATION_H_
-#define WEBRTC_MODULES_AUDIO_CODING_NETEQ_CROSS_CORRELATION_H_
-
-#include "webrtc/common_types.h"
-
-namespace webrtc {
-
-// The function calculates the cross-correlation between two sequences
-// |sequence_1| and |sequence_2|. |sequence_1| is taken as reference, with
-// |sequence_1_length| as its length. |sequence_2| slides for the calculation of
-// cross-correlation. The result will be saved in |cross_correlation|.
-// |cross_correlation_length| correlation points are calculated.
-// The corresponding lag starts from 0, and increases with a step of
-// |cross_correlation_step|. The result is without normalization. To avoid
-// overflow, the result will be right shifted. The amount of shifts will be
-// returned.
-//
-// Input:
-//     - sequence_1     : First sequence (reference).
-//     - sequence_2     : Second sequence (sliding during calculation).
-//     - sequence_1_length : Length of |sequence_1|.
-//     - cross_correlation_length : Number of cross-correlations to calculate.
-//     - cross_correlation_step : Step in the lag for the cross-correlation.
-//
-// Output:
-//      - cross_correlation : The cross-correlation in Q(-right_shifts)
-//
-// Return:
-//      Number of right shifts in cross_correlation.
-
-int CrossCorrelationWithAutoShift(const int16_t* sequence_1,
-                                  const int16_t* sequence_2,
-                                  size_t sequence_1_length,
-                                  size_t cross_correlation_length,
-                                  int cross_correlation_step,
-                                  int32_t* cross_correlation);
-
-}  // namespace webrtc
-
-#endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_CROSS_CORRELATION_H_