/*
* simulate_lost() is called to simulate packet lost
*/
static pj_status_t transport_simulate_lost(pjmedia_transport *tp,
pjmedia_dir dir,
unsigned pct_lost)
{
struct tp_adapter *adapter = (struct tp_adapter*)tp;
return pjmedia_transport_simulate_lost(adapter->slave_tp, dir, pct_lost);
}
static pj_status_t transport_simulate_lost(pjmedia_transport *tp,
pjmedia_dir dir,
unsigned pct_lost)
{
transport_srtp *srtp = (transport_srtp *) tp;
return pjmedia_transport_simulate_lost(srtp->member_tp, dir, pct_lost);
}
static pj_status_t transport_simulate_lost(pjmedia_transport *tp,
pjmedia_dir dir,
unsigned pct_lost)
{
transport_srtp *srtp = (transport_srtp *) tp;
PJ_ASSERT_RETURN(tp, PJ_EINVAL);
return pjmedia_transport_simulate_lost(srtp->member_tp, dir, pct_lost);
}
/*
* simulate_lost() is called to simulate packet lost
*/
static pj_status_t transport_simulate_lost(pjmedia_transport *tp,
pjmedia_dir dir,
unsigned pct_lost)
{
struct tp_zrtp *zrtp = (struct tp_zrtp*)tp;
PJ_ASSERT_RETURN(tp, PJ_EINVAL);
return pjmedia_transport_simulate_lost(zrtp->slave_tp, dir, pct_lost);
}
/* This is the transmission "tick".
* This function is called periodically every "tick" milliseconds, and
* it will determine whether to transmit packet(s) (or to drop it).
*/
static void tx_tick(const pj_time_val *t)
{
struct stream *strm = g_app.tx;
static char log_msg[120];
pjmedia_port *port = g_app.tx->port;
long pkt_interval;
/* packet interval, without jitter */
pkt_interval = PJMEDIA_PIA_SPF(&port->info) * 1000 /
PJMEDIA_PIA_SRATE(&port->info);
while (PJ_TIME_VAL_GTE(*t, strm->state.tx.next_schedule)) {
struct log_entry entry;
pj_bool_t drop_this_pkt = PJ_FALSE;
int jitter;
/* Init log entry */
pj_bzero(&entry, sizeof(entry));
entry.wall_clock = *t;
/*
* Determine whether to drop this packet
*/
if (strm->state.tx.cur_lost_burst) {
/* We are currently dropping packet */
/* Make it comply to minimum lost burst */
if (strm->state.tx.cur_lost_burst < g_app.cfg.tx_min_lost_burst) {
drop_this_pkt = PJ_TRUE;
}
/* Correlate the next packet loss */
if (!drop_this_pkt &&
strm->state.tx.cur_lost_burst < g_app.cfg.tx_max_lost_burst &&
MAX(strm->state.tx.total_lost-LOSS_EXTRA,0) * 100 / MAX(strm->state.tx.total_tx,1) < g_app.cfg.tx_pct_avg_lost
)
{
strm->state.tx.drop_prob = ((g_app.cfg.tx_pct_loss_corr * strm->state.tx.drop_prob) +
((100-g_app.cfg.tx_pct_loss_corr) * (pj_rand()%100))
) / 100;
if (strm->state.tx.drop_prob >= 100)
strm->state.tx.drop_prob = 99;
if (strm->state.tx.drop_prob >= 100 - g_app.cfg.tx_pct_avg_lost)
drop_this_pkt = PJ_TRUE;
}
}
/* If we're not dropping packet then use randomly distributed loss */
if (!drop_this_pkt &&
MAX(strm->state.tx.total_lost-LOSS_EXTRA,0) * 100 / MAX(strm->state.tx.total_tx,1) < g_app.cfg.tx_pct_avg_lost)
{
strm->state.tx.drop_prob = pj_rand() % 100;
if (strm->state.tx.drop_prob >= 100 - g_app.cfg.tx_pct_avg_lost)
drop_this_pkt = PJ_TRUE;
}
if (drop_this_pkt) {
/* Drop the frame */
pjmedia_transport_simulate_lost(g_app.loop, PJMEDIA_DIR_ENCODING, 100);
run_one_frame(g_app.tx_wav, g_app.tx->port, NULL);
pjmedia_transport_simulate_lost(g_app.loop, PJMEDIA_DIR_ENCODING, 0);
entry.event = EVENT_TX_DROP;
entry.log = "** This packet was lost **";
++strm->state.tx.total_lost;
++strm->state.tx.cur_lost_burst;
} else {
pjmedia_rtcp_stat stat;
pjmedia_jb_state jstate;
unsigned last_discard;
pjmedia_stream_get_stat_jbuf(g_app.rx->strm, &jstate);
last_discard = jstate.discard;
run_one_frame(g_app.tx_wav, g_app.tx->port, NULL);
pjmedia_stream_get_stat(g_app.rx->strm, &stat);
pjmedia_stream_get_stat_jbuf(g_app.rx->strm, &jstate);
entry.event = EVENT_TX;
entry.jb_state = &jstate;
entry.stat = &stat;
entry.log = log_msg;
if (jstate.discard > last_discard)
strcat(log_msg, "** Note: packet was discarded by jitter buffer **");
strm->state.tx.cur_lost_burst = 0;
}
write_log(&entry, PJ_TRUE);
++strm->state.tx.total_tx;
/* Calculate next schedule */
strm->state.tx.next_schedule.sec = 0;
strm->state.tx.next_schedule.msec = (strm->state.tx.total_tx + 1) * pkt_interval;
/* Apply jitter */
if (g_app.cfg.tx_max_jitter || g_app.cfg.tx_min_jitter) {
if (g_app.cfg.tx_max_jitter == g_app.cfg.tx_min_jitter) {
/* Fixed jitter */
switch (pj_rand() % 3) {
case 0:
jitter = 0 - g_app.cfg.tx_min_jitter;
break;
case 2:
jitter = g_app.cfg.tx_min_jitter;
break;
default:
jitter = 0;
break;
}
} else {
int jitter_range;
jitter_range = (g_app.cfg.tx_max_jitter-g_app.cfg.tx_min_jitter)*2;
jitter = pj_rand() % jitter_range;
if (jitter < jitter_range/2) {
jitter = 0 - g_app.cfg.tx_min_jitter - (jitter/2);
} else {
jitter = g_app.cfg.tx_min_jitter + (jitter/2);
}
}
} else {
jitter = 0;
}
pj_time_val_normalize(&strm->state.tx.next_schedule);
sprintf(log_msg, "** Packet #%u tick is at %d.%03d, %d ms jitter applied **",
strm->state.tx.total_tx+1,
(int)strm->state.tx.next_schedule.sec, (int)strm->state.tx.next_schedule.msec,
jitter);
strm->state.tx.next_schedule.msec += jitter;
pj_time_val_normalize(&strm->state.tx.next_schedule);
} /* while */
}
