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/common_audio/signal_processing/include/signal_processing_library.h"
12 #include "webrtc/modules/include/module_common_types.h"
13 #include "webrtc/system_wrappers/include/critical_section_wrapper.h"
14 #include "webrtc/voice_engine/level_indicator.h"
15
16 namespace webrtc {
17
18 namespace voe {
19
20 // Number of bars on the indicator.
21 // Note that the number of elements is specified because we are indexing it
22 // in the range of 0-32
23 const int8_t permutation[33] =
24 {0,1,2,3,4,4,5,5,5,5,6,6,6,6,6,7,7,7,7,8,8,8,9,9,9,9,9,9,9,9,9,9,9};
25
26
AudioLevel()27 AudioLevel::AudioLevel() :
28 _critSect(*CriticalSectionWrapper::CreateCriticalSection()),
29 _absMax(0),
30 _count(0),
31 _currentLevel(0),
32 _currentLevelFullRange(0) {
33 }
34
~AudioLevel()35 AudioLevel::~AudioLevel() {
36 delete &_critSect;
37 }
38
Clear()39 void AudioLevel::Clear()
40 {
41 CriticalSectionScoped cs(&_critSect);
42 _absMax = 0;
43 _count = 0;
44 _currentLevel = 0;
45 _currentLevelFullRange = 0;
46 }
47
ComputeLevel(const AudioFrame & audioFrame)48 void AudioLevel::ComputeLevel(const AudioFrame& audioFrame)
49 {
50 int16_t absValue(0);
51
52 // Check speech level (works for 2 channels as well)
53 absValue = WebRtcSpl_MaxAbsValueW16(
54 audioFrame.data_,
55 audioFrame.samples_per_channel_*audioFrame.num_channels_);
56
57 // Protect member access using a lock since this method is called on a
58 // dedicated audio thread in the RecordedDataIsAvailable() callback.
59 CriticalSectionScoped cs(&_critSect);
60
61 if (absValue > _absMax)
62 _absMax = absValue;
63
64 // Update level approximately 10 times per second
65 if (_count++ == kUpdateFrequency)
66 {
67 _currentLevelFullRange = _absMax;
68
69 _count = 0;
70
71 // Highest value for a int16_t is 0x7fff = 32767
72 // Divide with 1000 to get in the range of 0-32 which is the range of
73 // the permutation vector
74 int32_t position = _absMax/1000;
75
76 // Make it less likely that the bar stays at position 0. I.e. only if
77 // its in the range 0-250 (instead of 0-1000)
78 if ((position == 0) && (_absMax > 250))
79 {
80 position = 1;
81 }
82 _currentLevel = permutation[position];
83
84 // Decay the absolute maximum (divide by 4)
85 _absMax >>= 2;
86 }
87 }
88
Level() const89 int8_t AudioLevel::Level() const
90 {
91 CriticalSectionScoped cs(&_critSect);
92 return _currentLevel;
93 }
94
LevelFullRange() const95 int16_t AudioLevel::LevelFullRange() const
96 {
97 CriticalSectionScoped cs(&_critSect);
98 return _currentLevelFullRange;
99 }
100
101 } // namespace voe
102
103 } // namespace webrtc
104