media/webrtc/trunk/src/voice_engine/utility.cc

   1 /*
   2  *  Copyright (c) 2012 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 #include "utility.h"
  12
  13 #include "module.h"
  14 #include "trace.h"
  15 #include "signal_processing_library.h"
  16
  17 namespace webrtc
  18 {
  19
  20 namespace voe
  21 {
  22 enum{kMaxTargetLen = 2*32*10}; // stereo 32KHz 10ms
  23
  24 void Utility::MixWithSat(WebRtc_Word16 target[],
  25                          int target_channel,
  26                          const WebRtc_Word16 source[],
  27                          int source_channel,
  28                          int source_len)
  29 {
  30     assert((target_channel == 1) || (target_channel == 2));
  31     assert((source_channel == 1) || (source_channel == 2));
  32     assert(source_len <= kMaxTargetLen);
  33
  34     if ((target_channel == 2) && (source_channel == 1))
  35     {
  36         // Convert source from mono to stereo.
  37         WebRtc_Word32 left = 0;
  38         WebRtc_Word32 right = 0;
  39         for (int i = 0; i < source_len; ++i) {
  40             left  = source[i] + target[i*2];
  41             right = source[i] + target[i*2 + 1];
  42             target[i*2]     = WebRtcSpl_SatW32ToW16(left);
  43             target[i*2 + 1] = WebRtcSpl_SatW32ToW16(right);
  44         }
  45     }
  46     else if ((target_channel == 1) && (source_channel == 2))
  47     {
  48         // Convert source from stereo to mono.
  49         WebRtc_Word32 temp = 0;
  50         for (int i = 0; i < source_len/2; ++i) {
  51           temp = ((source[i*2] + source[i*2 + 1])>>1) + target[i];
  52           target[i] = WebRtcSpl_SatW32ToW16(temp);
  53         }
  54     }
  55     else
  56     {
  57         WebRtc_Word32 temp = 0;
  58         for (int i = 0; i < source_len; ++i) {
  59           temp = source[i] + target[i];
  60           target[i] = WebRtcSpl_SatW32ToW16(temp);
  61         }
  62     }
  63 }
  64
  65 void Utility::MixSubtractWithSat(WebRtc_Word16 target[],
  66                                  const WebRtc_Word16 source[],
  67                                  WebRtc_UWord16 len)
  68 {
  69     WebRtc_Word32 temp(0);
  70     for (int i = 0; i < len; i++)
  71     {
  72         temp = target[i] - source[i];
  73         if (temp > 32767)
  74             target[i] = 32767;
  75         else if (temp < -32768)
  76             target[i] = -32768;
  77         else
  78             target[i] = (WebRtc_Word16) temp;
  79     }
  80 }
  81
  82 void Utility::MixAndScaleWithSat(WebRtc_Word16 target[],
  83                                  const WebRtc_Word16 source[], float scale,
  84                                  WebRtc_UWord16 len)
  85 {
  86     WebRtc_Word32 temp(0);
  87     for (int i = 0; i < len; i++)
  88     {
  89         temp = (WebRtc_Word32) (target[i] + scale * source[i]);
  90         if (temp > 32767)
  91             target[i] = 32767;
  92         else if (temp < -32768)
  93             target[i] = -32768;
  94         else
  95             target[i] = (WebRtc_Word16) temp;
  96     }
  97 }
  98
  99 void Utility::Scale(WebRtc_Word16 vector[], float scale, WebRtc_UWord16 len)
 100 {
 101     for (int i = 0; i < len; i++)
 102     {
 103         vector[i] = (WebRtc_Word16) (scale * vector[i]);
 104     }
 105 }
 106
 107 void Utility::ScaleWithSat(WebRtc_Word16 vector[], float scale,
 108                            WebRtc_UWord16 len)
 109 {
 110     WebRtc_Word32 temp(0);
 111     for (int i = 0; i < len; i++)
 112     {
 113         temp = (WebRtc_Word32) (scale * vector[i]);
 114         if (temp > 32767)
 115             vector[i] = 32767;
 116         else if (temp < -32768)
 117             vector[i] = -32768;
 118         else
 119             vector[i] = (WebRtc_Word16) temp;
 120     }
 121 }
 122
 123 } // namespace voe
 124
 125 } // namespace webrtc