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freeswitch_rs/include/switch_estimators.h

101 lines
3.3 KiB
C

/*
* FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
* Copyright (C) 2005-2015, Anthony Minessale II <anthm@freeswitch.org>
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
*
* The Initial Developer of the Original Code is
* Anthony Minessale II <anthm@freeswitch.org>
* Portions created by the Initial Developer are Copyright (C)
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Dragos Oancea <droancea@yahoo.com>
*
* switch_estimators.h -- Estimators for Packet Loss, Jitter, RTT , etc
*
*/
#ifndef SWITCH_ESTIMATORS_H
#define SWITCH_ESTIMATORS_H
#include <switch.h>
SWITCH_BEGIN_EXTERN_C
struct kalman_estimator_s {
/* initial values for the Kalman filter */
float val_estimate_last ;
float P_last ;
/* the noise in the system:
The amount of noise in your measurements and the state-transitions
(e.g. the standard deviation of the signal noise, and how 'wrong' your simplified model
of the state-transitions are) => These are Q and R matrices */
float Q ; /* the process noise covariance matrix */
float R ; /* the measurement noise covariance matrix */
float K; /* P_temp * H^T * (H* P_temp * H^T + R)^-1 */
float P; /* the Kalman gain (calculated) */
float val_estimate; /* x_temp_est + K * (z_measured - H * x_temp_est) */
float val_measured; /* the 'noisy' value we measured */
};
struct cusum_kalman_detector_s {
/* initial values for the CUSUM Kalman filter */
float val_estimate_last;
float val_desired_last;
float P_last;
float K_last;
float delta;
float measurement_noise_e;
float variance_Re;
float measurement_noise_v;
float variance_Rv;
float g_last;
/*constants per model*/
float epsilon;
float h;
/* for calculating variance */
float last_average;
float last_q;
float N; /*how many samples we have so far (eg: how many RTCP we received, granted that we can calculate RTT for each one of them)*/
};
typedef struct kalman_estimator_s kalman_estimator_t;
typedef struct cusum_kalman_detector_s cusum_kalman_detector_t;
SWITCH_DECLARE(void) switch_kalman_init(kalman_estimator_t *est, float Q, float R);
SWITCH_DECLARE(switch_bool_t) switch_kalman_cusum_init(cusum_kalman_detector_t *detect_change, float epsilon,float h);
SWITCH_DECLARE(switch_bool_t) switch_kalman_estimate(kalman_estimator_t * est, float measurement, int system_model);
SWITCH_DECLARE (switch_bool_t) switch_kalman_cusum_detect_change(cusum_kalman_detector_t * detector, float measurement, float rtt_avg);
SWITCH_DECLARE(switch_bool_t) switch_kalman_is_slow_link(kalman_estimator_t * est_loss, kalman_estimator_t * est_rtt);
SWITCH_END_EXTERN_C
#endif
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