76 lines
2.9 KiB
C
76 lines
2.9 KiB
C
|
/*
|
||
|
|
* Copyright (c) 2011 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef AUDIO_AUDIO_LEVEL_H_
|
||
|
|
#define AUDIO_AUDIO_LEVEL_H_
|
||
|
|
|
||
|
|
#include "rtc_base/synchronization/mutex.h"
|
||
|
|
#include "rtc_base/thread_annotations.h"
|
||
|
|
|
||
|
|
namespace webrtc {
|
||
|
|
|
||
|
|
class AudioFrame;
|
||
|
|
namespace voe {
|
||
|
|
|
||
|
|
// This class is thread-safe. However, TotalEnergy() and TotalDuration() are
|
||
|
|
// related, so if you call ComputeLevel() on a different thread than you read
|
||
|
|
// these values, you still need to use lock to read them as a pair.
|
||
|
|
class AudioLevel {
|
||
|
|
public:
|
||
|
|
AudioLevel();
|
||
|
|
~AudioLevel();
|
||
|
|
void Reset();
|
||
|
|
|
||
|
|
// Returns the current audio level linearly [0,32767], which gets updated
|
||
|
|
// every "kUpdateFrequency+1" call to ComputeLevel() based on the maximum
|
||
|
|
// audio level of any audio frame, decaying by a factor of 1/4 each time
|
||
|
|
// LevelFullRange() gets updated.
|
||
|
|
// Called on "API thread(s)" from APIs like VoEBase::CreateChannel(),
|
||
|
|
// VoEBase::StopSend().
|
||
|
|
int16_t LevelFullRange() const;
|
||
|
|
void ResetLevelFullRange();
|
||
|
|
// See the description for "totalAudioEnergy" in the WebRTC stats spec
|
||
|
|
// (https://w3c.github.io/webrtc-stats/#dom-rtcaudiohandlerstats-totalaudioenergy)
|
||
|
|
// In our implementation, the total audio energy increases by the
|
||
|
|
// energy-equivalent of LevelFullRange() at the time of ComputeLevel(), rather
|
||
|
|
// than the energy of the samples in that specific audio frame. As a result,
|
||
|
|
// we may report a higher audio energy and audio level than the spec mandates.
|
||
|
|
// TODO(https://crbug.com/webrtc/10784): We should either do what the spec
|
||
|
|
// says or update the spec to match our implementation. If we want to have a
|
||
|
|
// decaying audio level we should probably update both the spec and the
|
||
|
|
// implementation to reduce the complexity of the definition. If we want to
|
||
|
|
// continue to have decaying audio we should have unittests covering the
|
||
|
|
// behavior of the decay.
|
||
|
|
double TotalEnergy() const;
|
||
|
|
double TotalDuration() const;
|
||
|
|
|
||
|
|
// Called on a native capture audio thread (platform dependent) from the
|
||
|
|
// AudioTransport::RecordedDataIsAvailable() callback.
|
||
|
|
// In Chrome, this method is called on the AudioInputDevice thread.
|
||
|
|
void ComputeLevel(const AudioFrame& audioFrame, double duration);
|
||
|
|
|
||
|
|
private:
|
||
|
|
enum { kUpdateFrequency = 10 };
|
||
|
|
|
||
|
|
mutable Mutex mutex_;
|
||
|
|
|
||
|
|
int16_t abs_max_ RTC_GUARDED_BY(mutex_);
|
||
|
|
int16_t count_ RTC_GUARDED_BY(mutex_);
|
||
|
|
int16_t current_level_full_range_ RTC_GUARDED_BY(mutex_);
|
||
|
|
|
||
|
|
double total_energy_ RTC_GUARDED_BY(mutex_) = 0.0;
|
||
|
|
double total_duration_ RTC_GUARDED_BY(mutex_) = 0.0;
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace voe
|
||
|
|
} // namespace webrtc
|
||
|
|
|
||
|
|
#endif // AUDIO_AUDIO_LEVEL_H_
|