twjit.h

/*
 * Themyscira Wireless RTP jitter buffer implementation:
 * public API definition for Osmocom-integrated version.
 *
 * This code was contributed to Osmocom Cellular Network Infrastructure
 * project by Mother Mychaela N. Falconia of Themyscira Wireless.
 * Mother Mychaela's contributions are NOT subject to copyright:
 * no rights reserved, all rights relinquished.
 */
 
#pragma once
 
#include <stdint.h>
#include <stdbool.h>
 
#include <osmocom/core/msgb.h>
 
struct osmo_twjit;
 
struct osmo_twjit_config;
 
struct osmo_twjit_stats {
        /* For ABI reasons, none of the following fields may be deleted
         * or reordered! */
 
        /* normal operation */
        uint32_t rx_packets;
        uint32_t delivered_pkt;
        uint32_t handovers_in;
        uint32_t handovers_out;
        uint32_t marker_resets;
        /* undesirable, but not totally unexpected */
        uint32_t too_old;
        uint32_t underruns;
        uint32_t ho_underruns;
        uint32_t output_gaps;
        uint32_t thinning_drops;
        /* unusual error events */
        uint32_t bad_packets;
        uint32_t duplicate_ts;
        /* independent analysis of Rx packet stream */
        uint32_t ssrc_changes;
        uint32_t seq_skips;
        uint32_t seq_backwards;
        uint32_t seq_repeats;
        uint32_t intentional_gaps;
        uint32_t ts_resets;
        uint32_t jitter_max;
        /* New fields may be added here at the end; once added, they become
         * permanent like the initially defined ones. */
};
 
struct osmo_twjit_rr_info {
        /* For ABI reasons, none of the following fields may be deleted
         * or reordered! */
 
        uint32_t ssrc;
        uint32_t rx_packets;
        uint32_t base_seq;
        uint32_t max_seq_ext;
        uint32_t expected_pkt;
        uint32_t jitter_accum;
        /* New fields may be added here at the end; once added, they become
         * permanent like the initially defined ones. */
};
 
/* twjit API: managing configuration structures */
 
struct osmo_twjit_config *osmo_twjit_config_alloc(void *ctx);
void osmo_twjit_config_free(struct osmo_twjit_config *conf);
 
int osmo_twjit_config_set_buffer_depth(struct osmo_twjit_config *conf,
                                        uint16_t bd_start, uint16_t bd_hiwat);
int osmo_twjit_config_set_thinning_int(struct osmo_twjit_config *conf,
                                        uint16_t thinning_int);
int osmo_twjit_config_set_max_future_sec(struct osmo_twjit_config *conf,
                                         uint16_t max_future_sec);
int osmo_twjit_config_set_start_min_delta(struct osmo_twjit_config *conf,
                                          uint16_t delta_ms);
int osmo_twjit_config_set_start_max_delta(struct osmo_twjit_config *conf,
                                          uint16_t delta_ms);
int osmo_twjit_config_set_handover_on_marker(struct osmo_twjit_config *conf,
                                             bool hom);
 
/* twjit API: actual twjit instances */
 
struct osmo_twjit *osmo_twjit_create(void *ctx, uint16_t clock_khz,
                                     uint16_t quantum_ms,
                                     const struct osmo_twjit_config *config);
void osmo_twjit_destroy(struct osmo_twjit *twjit);
 
int osmo_twjit_set_config(struct osmo_twjit *twjit,
                          const struct osmo_twjit_config *config);
void osmo_twjit_reset(struct osmo_twjit *twjit);
 
/* RTP input, takes ownership of msgb */
void osmo_twjit_input(struct osmo_twjit *twjit, struct msgb *msg);
 
/* output function, to be called by TDM/GSM/etc fixed-timing side */
struct msgb *osmo_twjit_output(struct osmo_twjit *twjit);
 
/* Stats and RR info structures are contained inside opaque struct osmo_twjit.
 * We need to provide access to these stats and RR info structures to API
 * users, but we don't want to make the whole twjit instance struct public.
 * Also we would like to have fast external access to these stats, hence an API
 * that copies our stats to caller-provided storage would be very inefficient.
 * Compromise: we allow direct external access to just these selected parts
 * of the full internal state structure by providing API functions that
 * return pointers to these selected parts.
 */
const struct osmo_twjit_stats *
osmo_twjit_get_stats(struct osmo_twjit *twjit);
 
const struct osmo_twjit_rr_info *
osmo_twjit_get_rr_info(struct osmo_twjit *twjit);
 
/* When we compose outgoing RTCP packets in the upper layer of twrtp,
 * we need to know whether or not we have received at least one valid
 * RTP data packet so far.  If we haven't received any RTP yet, then
 * we have no Rx SSRC, all data in struct osmo_twjit_rr_info are invalid,
 * and we cannot send RTCP reception reports.
 */
bool osmo_twjit_rr_info_valid(struct osmo_twjit *twjit);
 
/* vty configuration functions */
 
void osmo_twjit_vty_init(int twjit_node);
 
struct vty;
 
int osmo_twjit_config_write(struct vty *vty,
                            const struct osmo_twjit_config *conf,
                            const char *prefix);