Line data    Source code

       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 "webrtc/modules/audio_conference_mixer/source/audio_frame_manipulator.h"
      12             : #include "webrtc/modules/include/module_common_types.h"
      13             : #include "webrtc/typedefs.h"
      14             : 
      15             : namespace {
      16             : // Linear ramping over 80 samples.
      17             : // TODO(hellner): ramp using fix point?
      18             : const float rampArray[] = {0.0000f, 0.0127f, 0.0253f, 0.0380f,
      19             :                            0.0506f, 0.0633f, 0.0759f, 0.0886f,
      20             :                            0.1013f, 0.1139f, 0.1266f, 0.1392f,
      21             :                            0.1519f, 0.1646f, 0.1772f, 0.1899f,
      22             :                            0.2025f, 0.2152f, 0.2278f, 0.2405f,
      23             :                            0.2532f, 0.2658f, 0.2785f, 0.2911f,
      24             :                            0.3038f, 0.3165f, 0.3291f, 0.3418f,
      25             :                            0.3544f, 0.3671f, 0.3797f, 0.3924f,
      26             :                            0.4051f, 0.4177f, 0.4304f, 0.4430f,
      27             :                            0.4557f, 0.4684f, 0.4810f, 0.4937f,
      28             :                            0.5063f, 0.5190f, 0.5316f, 0.5443f,
      29             :                            0.5570f, 0.5696f, 0.5823f, 0.5949f,
      30             :                            0.6076f, 0.6203f, 0.6329f, 0.6456f,
      31             :                            0.6582f, 0.6709f, 0.6835f, 0.6962f,
      32             :                            0.7089f, 0.7215f, 0.7342f, 0.7468f,
      33             :                            0.7595f, 0.7722f, 0.7848f, 0.7975f,
      34             :                            0.8101f, 0.8228f, 0.8354f, 0.8481f,
      35             :                            0.8608f, 0.8734f, 0.8861f, 0.8987f,
      36             :                            0.9114f, 0.9241f, 0.9367f, 0.9494f,
      37             :                            0.9620f, 0.9747f, 0.9873f, 1.0000f};
      38             : const size_t rampSize = sizeof(rampArray)/sizeof(rampArray[0]);
      39             : }  // namespace
      40             : 
      41             : namespace webrtc {
      42           0 : uint32_t CalculateEnergy(const AudioFrame& audioFrame)
      43             : {
      44           0 :     uint32_t energy = 0;
      45           0 :     for(size_t position = 0; position < audioFrame.samples_per_channel_;
      46             :         position++)
      47             :     {
      48             :         // TODO(andrew): this can easily overflow.
      49           0 :         energy += audioFrame.data_[position] * audioFrame.data_[position];
      50             :     }
      51           0 :     return energy;
      52             : }
      53             : 
      54           0 : void RampIn(AudioFrame& audioFrame)
      55             : {
      56           0 :     assert(rampSize <= audioFrame.samples_per_channel_);
      57           0 :     for(size_t i = 0; i < rampSize; i++)
      58             :     {
      59           0 :         audioFrame.data_[i] = static_cast<int16_t>(rampArray[i] *
      60           0 :                                                    audioFrame.data_[i]);
      61             :     }
      62           0 : }
      63             : 
      64           0 : void RampOut(AudioFrame& audioFrame)
      65             : {
      66           0 :     assert(rampSize <= audioFrame.samples_per_channel_);
      67           0 :     for(size_t i = 0; i < rampSize; i++)
      68             :     {
      69           0 :         const size_t rampPos = rampSize - 1 - i;
      70           0 :         audioFrame.data_[i] = static_cast<int16_t>(rampArray[rampPos] *
      71           0 :                                                    audioFrame.data_[i]);
      72             :     }
      73           0 :     memset(&audioFrame.data_[rampSize], 0,
      74           0 :            (audioFrame.samples_per_channel_ - rampSize) *
      75           0 :            sizeof(audioFrame.data_[0]));
      76           0 : }
      77             : }  // namespace webrtc