99 lines
3.0 KiB
C++
99 lines
3.0 KiB
C++
|
/*
|
||
|
|
* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
|
||
|
|
*
|
||
|
|
* Use of this source code is governed by a BSD-style license
|
||
|
|
* that can be found in the LICENSE file in the root of the source
|
||
|
|
* tree. An additional intellectual property rights grant can be found
|
||
|
|
* in the file PATENTS. All contributing project authors may
|
||
|
|
* be found in the AUTHORS file in the root of the source tree.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "audio/audio_level.h"
|
||
|
|
|
||
|
|
#include "api/audio/audio_frame.h"
|
||
|
|
#include "common_audio/signal_processing/include/signal_processing_library.h"
|
||
|
|
|
||
|
|
namespace webrtc {
|
||
|
|
namespace voe {
|
||
|
|
|
||
|
|
AudioLevel::AudioLevel()
|
||
|
|
: abs_max_(0), count_(0), current_level_full_range_(0) {}
|
||
|
|
|
||
|
|
AudioLevel::~AudioLevel() {}
|
||
|
|
|
||
|
|
void AudioLevel::Reset() {
|
||
|
|
MutexLock lock(&mutex_);
|
||
|
|
abs_max_ = 0;
|
||
|
|
count_ = 0;
|
||
|
|
current_level_full_range_ = 0;
|
||
|
|
total_energy_ = 0.0;
|
||
|
|
total_duration_ = 0.0;
|
||
|
|
}
|
||
|
|
|
||
|
|
int16_t AudioLevel::LevelFullRange() const {
|
||
|
|
MutexLock lock(&mutex_);
|
||
|
|
return current_level_full_range_;
|
||
|
|
}
|
||
|
|
|
||
|
|
void AudioLevel::ResetLevelFullRange() {
|
||
|
|
MutexLock lock(&mutex_);
|
||
|
|
abs_max_ = 0;
|
||
|
|
count_ = 0;
|
||
|
|
current_level_full_range_ = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
double AudioLevel::TotalEnergy() const {
|
||
|
|
MutexLock lock(&mutex_);
|
||
|
|
return total_energy_;
|
||
|
|
}
|
||
|
|
|
||
|
|
double AudioLevel::TotalDuration() const {
|
||
|
|
MutexLock lock(&mutex_);
|
||
|
|
return total_duration_;
|
||
|
|
}
|
||
|
|
|
||
|
|
void AudioLevel::ComputeLevel(const AudioFrame& audioFrame, double duration) {
|
||
|
|
// Check speech level (works for 2 channels as well)
|
||
|
|
int16_t abs_value =
|
||
|
|
audioFrame.muted()
|
||
|
|
? 0
|
||
|
|
: WebRtcSpl_MaxAbsValueW16(
|
||
|
|
audioFrame.data(),
|
||
|
|
audioFrame.samples_per_channel_ * audioFrame.num_channels_);
|
||
|
|
|
||
|
|
// Protect member access using a lock since this method is called on a
|
||
|
|
// dedicated audio thread in the RecordedDataIsAvailable() callback.
|
||
|
|
MutexLock lock(&mutex_);
|
||
|
|
|
||
|
|
if (abs_value > abs_max_)
|
||
|
|
abs_max_ = abs_value;
|
||
|
|
|
||
|
|
// Update level approximately 9 times per second, assuming audio frame
|
||
|
|
// duration is approximately 10 ms. (The update frequency is every
|
||
|
|
// 11th (= |kUpdateFrequency+1|) call: 1000/(11*10)=9.09..., we should
|
||
|
|
// probably change this behavior, see https://crbug.com/webrtc/10784).
|
||
|
|
if (count_++ == kUpdateFrequency) {
|
||
|
|
current_level_full_range_ = abs_max_;
|
||
|
|
|
||
|
|
count_ = 0;
|
||
|
|
|
||
|
|
// Decay the absolute maximum (divide by 4)
|
||
|
|
abs_max_ >>= 2;
|
||
|
|
}
|
||
|
|
|
||
|
|
// See the description for "totalAudioEnergy" in the WebRTC stats spec
|
||
|
|
// (https://w3c.github.io/webrtc-stats/#dom-rtcmediastreamtrackstats-totalaudioenergy)
|
||
|
|
// for an explanation of these formulas. In short, we need a value that can
|
||
|
|
// be used to compute RMS audio levels over different time intervals, by
|
||
|
|
// taking the difference between the results from two getStats calls. To do
|
||
|
|
// this, the value needs to be of units "squared sample value * time".
|
||
|
|
double additional_energy =
|
||
|
|
static_cast<double>(current_level_full_range_) / INT16_MAX;
|
||
|
|
additional_energy *= additional_energy;
|
||
|
|
total_energy_ += additional_energy * duration;
|
||
|
|
total_duration_ += duration;
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace voe
|
||
|
|
} // namespace webrtc
|