Changeset 388 for pjproject/trunk/pjmedia/src/pjmedia/rtcp.c

Timestamp:

Apr 5, 2006 7:08:16 PM (18 years ago)

Author:

bennylp

Message:

Added detection/protection against inaccurate timestamp in RTCP

File:

• pjproject/trunk/pjmedia/src/pjmedia/rtcp.c (modified) (6 diffs)

pjproject/trunk/pjmedia/src/pjmedia/rtcp.c

@@ -38 +38 @@
 #   define TRACE_(x)    PJ_LOG(3,x)
 #else
-#   define TRACE_(x)
+#   define TRACE_(x)    ;
 #endif
 
@@ -190 +190 @@
     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)) {
@@ -221 +225 @@
             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,
@@ -232 +236 @@
                 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"));
             }
         }
@@ -302 +306 @@
         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.
@@ -314 +322 @@
 
         /* 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 ));
     }