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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 { | |
16 // Linear ramping over 80 samples. | |
17 // TODO(hellner): ramp using fix point? | |
18 const float rampArray[] = { | |
19 0.0000f, 0.0127f, 0.0253f, 0.0380f, 0.0506f, 0.0633f, 0.0759f, 0.0886f, | |
20 0.1013f, 0.1139f, 0.1266f, 0.1392f, 0.1519f, 0.1646f, 0.1772f, 0.1899f, | |
21 0.2025f, 0.2152f, 0.2278f, 0.2405f, 0.2532f, 0.2658f, 0.2785f, 0.2911f, | |
22 0.3038f, 0.3165f, 0.3291f, 0.3418f, 0.3544f, 0.3671f, 0.3797f, 0.3924f, | |
23 0.4051f, 0.4177f, 0.4304f, 0.4430f, 0.4557f, 0.4684f, 0.4810f, 0.4937f, | |
24 0.5063f, 0.5190f, 0.5316f, 0.5443f, 0.5570f, 0.5696f, 0.5823f, 0.5949f, | |
25 0.6076f, 0.6203f, 0.6329f, 0.6456f, 0.6582f, 0.6709f, 0.6835f, 0.6962f, | |
26 0.7089f, 0.7215f, 0.7342f, 0.7468f, 0.7595f, 0.7722f, 0.7848f, 0.7975f, | |
27 0.8101f, 0.8228f, 0.8354f, 0.8481f, 0.8608f, 0.8734f, 0.8861f, 0.8987f, | |
28 0.9114f, 0.9241f, 0.9367f, 0.9494f, 0.9620f, 0.9747f, 0.9873f, 1.0000f}; | |
29 const size_t rampSize = sizeof(rampArray) / sizeof(rampArray[0]); | |
30 } // namespace | |
31 | |
32 namespace webrtc { | |
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(rampSize <= audio_frame->samples_per_channel_); | |
45 for (size_t i = 0; i < rampSize; i++) { | |
46 audio_frame->data_[i] = | |
47 static_cast<int16_t>(rampArray[i] * audio_frame->data_[i]); | |
48 } | |
49 } | |
50 | |
51 void NewMixerRampOut(AudioFrame* audio_frame) { | |
52 assert(rampSize <= audio_frame->samples_per_channel_); | |
53 for (size_t i = 0; i < rampSize; i++) { | |
54 const size_t rampPos = rampSize - 1 - i; | |
55 audio_frame->data_[i] = | |
56 static_cast<int16_t>(rampArray[rampPos] * audio_frame->data_[i]); | |
57 } | |
58 memset(&audio_frame->data_[rampSize], 0, | |
59 (audio_frame->samples_per_channel_ - rampSize) * | |
60 sizeof(audio_frame->data_[0])); | |
61 } | |
62 } // namespace webrtc | |
aleloi
2016/08/11 07:49:55
This is copied from modules/audio_conference_mixer
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