From 3cff5c33e4120cbf4319a19bf54d0d6fe55e6ce1 Mon Sep 17 00:00:00 2001 From: Benny Prijono Date: Wed, 5 Apr 2006 19:08:16 +0000 Subject: Added detection/protection against inaccurate timestamp in RTCP git-svn-id: http://svn.pjsip.org/repos/pjproject/trunk@388 74dad513-b988-da41-8d7b-12977e46ad98 --- pjmedia/src/pjmedia/rtcp.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) (limited to 'pjmedia/src') diff --git a/pjmedia/src/pjmedia/rtcp.c b/pjmedia/src/pjmedia/rtcp.c index b522c279..dd3ca304 100644 --- a/pjmedia/src/pjmedia/rtcp.c +++ b/pjmedia/src/pjmedia/rtcp.c @@ -37,7 +37,7 @@ #if 0 # define TRACE_(x) PJ_LOG(3,x) #else -# define TRACE_(x) +# define TRACE_(x) ; #endif /* @@ -189,6 +189,10 @@ PJ_DEF(void) pjmedia_rtcp_rx_rtcp( pjmedia_rtcp_session *session, /* Calculate SR arrival time for DLSR */ pj_get_timestamp(&session->rx_lsr_time); + TRACE_((THIS_FILE, "Rx RTCP SR: ntp-ts=%p, time=%p", + session->rx_lsr, + (pj_uint32_t)(session->rx_lsr_time.u64*65536/session->ts_freq.u64))); + /* Calculate RTT if it has RR */ if (size >= sizeof(pjmedia_rtcp_pkt)) { @@ -220,7 +224,7 @@ PJ_DEF(void) pjmedia_rtcp_rx_rtcp( pjmedia_rtcp_session *session, */ eedelay = (eedelay * 1000000) >> 16; - TRACE_((THIS_FILE, "Rx RTCP: lsr=%p, dlsr=%p (%d:%03dms), " + TRACE_((THIS_FILE, "Rx RTCP RR: lsr=%p, dlsr=%p (%d:%03dms), " "now=%p, rtt=%p", lsr, dlsr, dlsr/65536, (dlsr%65536)*1000/65536, now, (pj_uint32_t)eedelay)); @@ -231,7 +235,7 @@ PJ_DEF(void) pjmedia_rtcp_rx_rtcp( pjmedia_rtcp_session *session, if (now-dlsr >= lsr) { session->rtt_us = (pj_uint32_t)eedelay; } else { - TRACE_((THIS_FILE, "NTP clock running backwards?")); + PJ_LOG(3, (THIS_FILE, "Internal NTP clock skew detected")); } } } @@ -301,7 +305,11 @@ PJ_DEF(void) pjmedia_rtcp_build_rtcp(pjmedia_rtcp_session *session, pj_timestamp ts; pj_uint32_t lsr = session->rx_lsr; pj_uint64_t lsr_time = session->rx_lsr_time.u64; + pj_uint32_t dlsr; + /* Convert LSR time to 1/65536 seconds resolution */ + lsr_time = (lsr_time << 16) / session->ts_freq.u64; + /* Fill in LSR. LSR is the middle 32bit of the last SR NTP time received. */ @@ -313,9 +321,20 @@ PJ_DEF(void) pjmedia_rtcp_build_rtcp(pjmedia_rtcp_session *session, pj_get_timestamp(&ts); /* Convert interval to 1/65536 seconds value */ - ts.u64 = ((ts.u64 - lsr_time) << 16) / session->ts_freq.u64; - - rtcp_pkt->rr.dlsr = pj_htonl( (pj_uint32_t)ts.u64 ); + ts.u64 = (ts.u64 << 16) / session->ts_freq.u64; + + /* Get DLSR */ + dlsr = (pj_uint32_t)(ts.u64 - lsr_time); + rtcp_pkt->rr.dlsr = pj_htonl(dlsr); + + TRACE_((THIS_FILE, "Tx RTCP RR: lsr=%p, lsr_time=%p, now=%p, dlsr=%p" + "(%ds:%03dms)", + lsr, + (pj_uint32_t)lsr_time, + (pj_uint32_t)ts.u64, + dlsr, + dlsr/65536, + (dlsr%65536)*1000/65536 )); } -- cgit v1.2.3