FS-8644: OPUS_SET_BITRATE(), codec control and estimators for packet loss and RTT (with Kalman filters) to detect a slow or congested link.

Feature enabled with "adjust-bitrate" in opus.conf.xml - it's a feedback loop with incoming RTCP.

src/include/switch.h

@@ -144,6 +144,7 @@
 #include "switch_core_media.h"
 #include "switch_core_video.h"
 #include "switch_jitterbuffer.h"
+#include "switch_estimators.h"
 #include <libteletone.h>
 
 

src/include/switch_core_media.h

@@ -322,6 +322,10 @@ SWITCH_DECLARE(switch_status_t) switch_core_media_codec_control(switch_core_sess
 																switch_codec_control_type_t *rtype,
 																void **ret_data);
 
+SWITCH_DECLARE(switch_bool_t) switch_core_media_codec_get_cap(switch_core_session_t *session, 
+																switch_media_type_t mtype,
+																switch_codec_flag_t flag);
+
 
 #define switch_core_media_gen_key_frame(_session) switch_core_media_codec_control(_session, SWITCH_MEDIA_TYPE_VIDEO, SWITCH_IO_WRITE, \
 																				  SCC_VIDEO_GEN_KEYFRAME, SCCT_NONE, NULL, SCCT_NONE, NULL, NULL, NULL) \

src/include/switch_estimators.h

@@ -0,0 +1,100 @@
+/* 
+ * 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
+
+/* For Emacs:
+ * Local Variables:
+ * mode:c
+ * indent-tabs-mode:t
+ * tab-width:4
+ * c-basic-offset:4
+ * End:
+ * For VIM:
+ * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
+ */

src/include/switch_types.h

@@ -755,6 +755,8 @@ typedef enum {
 	SWITCH_ZRTP_FLAG_SECURE_MITM_RECV,
 	SWITCH_RTP_FLAG_DEBUG_RTP_READ,
 	SWITCH_RTP_FLAG_DEBUG_RTP_WRITE,
+	SWITCH_RTP_FLAG_ESTIMATORS,
+	SWITCH_RTP_FLAG_ADJ_BITRATE_CAP,
 	SWITCH_RTP_FLAG_VIDEO,
 	SWITCH_RTP_FLAG_ENABLE_RTCP,
 	SWITCH_RTP_FLAG_RTCP_MUX,
@@ -1631,6 +1633,7 @@ typedef enum {
 	SWITCH_CODEC_FLAG_AAL2 = (1 << 6),
 	SWITCH_CODEC_FLAG_PASSTHROUGH = (1 << 7),
 	SWITCH_CODEC_FLAG_READY = (1 << 8),
+	SWITCH_CODEC_FLAG_HAS_ADJ_BITRATE = (1 << 14),
 	SWITCH_CODEC_FLAG_HAS_PLC = (1 << 15),
 	SWITCH_CODEC_FLAG_VIDEO_PATCHING = (1 << 16)
 } switch_codec_flag_enum_t;
@@ -2268,6 +2271,7 @@ typedef enum {
 	SCC_VIDEO_BANDWIDTH,
 	SCC_VIDEO_RESET,
 	SCC_AUDIO_PACKET_LOSS,
+	SCC_AUDIO_ADJUST_BITRATE,
 	SCC_DEBUG,
 	SCC_CODEC_SPECIFIC
 } switch_codec_control_command_t;
@@ -2586,6 +2590,12 @@ typedef struct switch_waitlist_s {
 struct switch_jb_s;
 typedef struct switch_jb_s switch_jb_t;
 
+//struct kalman_estimator_s;
+//typedef struct kalman_estimator_s kalman_estimator_t;
+
+//struct cusum_kalman_detector_s;
+//typedef struct cusum_kalman_detector_s cusum_kalman_detector_t;
+
 struct switch_img_txt_handle_s;
 typedef struct switch_img_txt_handle_s switch_img_txt_handle_t;