Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : 
      12             : /*
      13             :  * This file contains the function WebRtcSpl_GetScalingSquare().
      14             :  * The description header can be found in signal_processing_library.h
      15             :  *
      16             :  */
      17             : 
      18             : #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
      19             : 
      20           0 : int16_t WebRtcSpl_GetScalingSquare(int16_t* in_vector,
      21             :                                    size_t in_vector_length,
      22             :                                    size_t times)
      23             : {
      24           0 :     int16_t nbits = WebRtcSpl_GetSizeInBits((uint32_t)times);
      25             :     size_t i;
      26           0 :     int16_t smax = -1;
      27             :     int16_t sabs;
      28           0 :     int16_t *sptr = in_vector;
      29             :     int16_t t;
      30           0 :     size_t looptimes = in_vector_length;
      31             : 
      32           0 :     for (i = looptimes; i > 0; i--)
      33             :     {
      34           0 :         sabs = (*sptr > 0 ? *sptr++ : -*sptr++);
      35           0 :         smax = (sabs > smax ? sabs : smax);
      36             :     }
      37           0 :     t = WebRtcSpl_NormW32(WEBRTC_SPL_MUL(smax, smax));
      38             : 
      39           0 :     if (smax == 0)
      40             :     {
      41           0 :         return 0; // Since norm(0) returns 0
      42             :     } else
      43             :     {
      44           0 :         return (t > nbits) ? 0 : nbits - t;
      45             :     }
      46             : }