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