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/* Copyright 2020 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef EWMA_POWER_H_
#define EWMA_POWER_H_
#include <stdbool.h>
#include <stdint.h>
#include "cras_audio_area.h"
* The exponentially weighted moving average power module used to
* calculate the energe level in audio stream.
* Members:
* power_set - Flag to note if the first power value has set.
* enabled - Flag to enable ewma calculation. Set to false to
* make all calculations no-ops.
* power - The power value.
* step_fr - How many frames to sample one for EWMA calculation.
struct ewma_power {
bool power_set;
bool enabled;
float power;
unsigned int step_fr;
* Disables the ewma instance.
void ewma_power_disable(struct ewma_power *ewma);
* Initializes the ewma_power object.
* Args:
* ewma - The ewma_power object to initialize.
* rate - The sample rate of the audio data that the ewma object
* will calculate power from.
void ewma_power_init(struct ewma_power *ewma, unsigned int rate);
* Feeds an audio buffer to ewma_power object to calculate the
* latest power value.
* Args:
* ewma - The ewma_power object to calculate power.
* buf - Pointer to the audio data.
* channels - Number of channels of the audio data.
* size - Length in frames of the audio data.
void ewma_power_calculate(struct ewma_power *ewma, const int16_t *buf,
unsigned int channels, unsigned int size);
* Feeds non-interleaved audio data to ewma_power to calculate the
* latest power value. This is similar to ewma_power_calculate but
* accepts cras_audio_area.
void ewma_power_calculate_area(struct ewma_power *ewma, const int16_t *buf,
struct cras_audio_area *area, unsigned int size);
#endif /* EWMA_POWER_H_ */