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Use smoothed time differences

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Mike Brady
2015-06-28 19:54:42 +01:00
parent fb5c4f3012
commit a61e6d319e
1 changed files with 15 additions and 5 deletions
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rtp.c
+15 -5
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@@ -49,6 +49,8 @@ typedef struct {
typedef struct time_ping_record {
uint64_t local_to_remote_difference;
uint64_t dispersion;
uint64_t local_time;
uint64_t remote_time;
} time_ping_record;
// only one RTP session can be active at a time.
@@ -373,11 +375,17 @@ static void *rtp_timing_receiver(void *arg) {
time_pings[cc].dispersion = (time_pings[cc].dispersion * 133) /
100; // make the dispersions 'age' by this rational factor
}
// these are for diagnostics only -- not used
time_pings[0].local_time = arrival_time;
time_pings[0].remote_time = distant_transmit_time;
time_pings[0].local_to_remote_difference = local_time_by_remote_clock - arrival_time;
time_pings[0].dispersion = return_time;
if (time_ping_count < time_ping_history)
time_ping_count++;
uint64_t local_time_chosen = arrival_time;;
uint64_t remote_time_chosen = distant_transmit_time;
// now pick the timestamp with the lowest dispersion
uint64_t l2rtd = time_pings[0].local_to_remote_difference;
uint64_t tld = time_pings[0].dispersion;
@@ -385,6 +393,8 @@ static void *rtp_timing_receiver(void *arg) {
if (time_pings[cc].dispersion < tld) {
l2rtd = time_pings[cc].local_to_remote_difference;
tld = time_pings[cc].dispersion;
local_time_chosen = time_pings[cc].local_time;
remote_time_chosen = time_pings[cc].remote_time;
}
int64_t ji;
@@ -412,12 +422,12 @@ static void *rtp_timing_receiver(void *arg) {
int64_t clock_drift, clock_drift_in_usec;
if (first_local_time==0) {
first_local_time = arrival_time;
first_remote_time = local_time_by_remote_clock;
first_local_time = local_time_chosen;
first_remote_time = remote_time_chosen;
uint64_t clock_drift = 0;
} else {
uint64_t local_time_change = arrival_time - first_local_time;
uint64_t remote_time_change = local_time_by_remote_clock - first_remote_time;
uint64_t local_time_change = local_time_chosen - first_local_time;
uint64_t remote_time_change = remote_time_chosen - first_remote_time;
if (local_time_change >= remote_time_change)
clock_drift = local_time_change - remote_time_change;