Changeset 427 for pjproject/trunk/pjmedia/src/pjmedia/rtcp.c

Timestamp:

May 2, 2006 5:47:51 PM (18 years ago)

Author:

bennylp

Message:

Fixed several bugs in RTCP and tested the compatibility. Fixed bugs: total lost byte order, RTCP RR parsing, normalizing large RTT, RX pkt lost online update.

File:

• pjproject/trunk/pjmedia/src/pjmedia/rtcp.c (modified) (14 diffs)

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

@@ -51 +51 @@
 {
 /* Seconds between 1900-01-01 to 1970-01-01 */
-#define NTP_DIFF    ((70 * 365 + 17) * 86400UL)
+#define JAN_1970  (2208988800UL)
     pj_timestamp ts;
     pj_status_t status;
@@ -59 +59 @@
     /* Fill up the high 32bit part */
     ntp->hi = (pj_uint32_t)((ts.u64 - sess->ts_base.u64) / sess->ts_freq.u64)
-              + sess->tv_base.sec + NTP_DIFF;
+              + sess->tv_base.sec + JAN_1970;
 
     /* Calculate seconds fractions */
@@ -95 +95 @@
         pj_gettimeofday(&elapsed);
 
-        ts_time.sec = ntp->hi - sess->tv_base.sec - NTP_DIFF;
+        ts_time.sec = ntp->hi - sess->tv_base.sec - JAN_1970;
         ts_time.msec = (long)(ntp->lo * 1000.0 / 0xFFFFFFFF);
 
@@ -114 +114 @@
 
 
-            ntp->hi = elapsed.sec + sess->tv_base.sec + NTP_DIFF;
+            ntp->hi = elapsed.sec + sess->tv_base.sec + JAN_1970;
             ntp->lo = (elapsed.msec * 65536 / 1000) << 16;
         }
@@ -217 +217 @@
     }
 
+    /* Only mark "good" packets */
+    ++sess->received;
+
     /* Calculate loss periods. */
     if (seq_st.diff > 1) {
@@ -224 +227 @@
         period = count * sess->pkt_size * 1000 / sess->clock_rate;
         period *= 1000;
+
+        /* Update packet lost. 
+         * The packet lost number will also be updated when we're sending
+         * outbound RTCP RR.
+         */
+        sess->stat.rx.loss += (seq_st.diff - 1);
 
         /* Update loss period stat */
@@ -241 +250 @@
 
 
-    /* Only mark "good" packets */
-    ++sess->received;
-
-
     /*
      * Calculate jitter only when sequence is good (see RFC 3550 section A.8)
@@ -304 +309 @@
                                    pj_size_t size)
 {
-    const struct pjmedia_rtcp_pkt *rtcp = pkt;
+    const pjmedia_rtcp_common *common = pkt;
+    const pjmedia_rtcp_rr *rr = NULL;
+    const pjmedia_rtcp_sr *sr = NULL;
     pj_uint32_t last_loss, jitter_samp, jitter;
 
-    /* Must at least contain SR */
-    pj_assert(size >= sizeof(pjmedia_rtcp_common)+sizeof(pjmedia_rtcp_sr));
-
-    /* Save LSR from NTP timestamp of RTCP packet */
-    sess->rx_lsr = ((pj_ntohl(rtcp->sr.ntp_sec) & 0x0000FFFF) << 16) | 
-                   ((pj_ntohl(rtcp->sr.ntp_frac) >> 16) & 0xFFFF);
-
-    /* Calculate SR arrival time for DLSR */
-    pj_get_timestamp(&sess->rx_lsr_time);
-
-    TRACE_((sess->name, "Rx RTCP SR: ntp_ts=%p", 
-            sess->rx_lsr,
-            (pj_uint32_t)(sess->rx_lsr_time.u64*65536/sess->ts_freq.u64)));
-
-    /* Nothing more to do if this is an SR only RTCP packet */
-    if (size < sizeof(pjmedia_rtcp_pkt))
+    /* Parse RTCP */
+    if (common->pt == RTCP_SR) {
+        sr = (pjmedia_rtcp_sr*) (((char*)pkt) + sizeof(pjmedia_rtcp_common));
+        if (common->count > 0 && size >= (sizeof(pjmedia_rtcp_pkt))) {
+            rr = (pjmedia_rtcp_rr*)(((char*)pkt) + (sizeof(pjmedia_rtcp_common)
+                                    + sizeof(pjmedia_rtcp_sr)));
+        }
+    } else if (common->pt == RTCP_RR && common->count > 0)
+        rr = (pjmedia_rtcp_rr*)(((char*)pkt) +sizeof(pjmedia_rtcp_common) +4);
+
+
+    if (sr) {
+        /* Save LSR from NTP timestamp of RTCP packet */
+        sess->rx_lsr = ((pj_ntohl(sr->ntp_sec) & 0x0000FFFF) << 16) | 
+                       ((pj_ntohl(sr->ntp_frac) >> 16) & 0xFFFF);
+
+        /* Calculate SR arrival time for DLSR */
+        pj_get_timestamp(&sess->rx_lsr_time);
+
+        TRACE_((sess->name, "Rx RTCP SR: ntp_ts=%p", 
+                sess->rx_lsr,
+                (pj_uint32_t)(sess->rx_lsr_time.u64*65536/sess->ts_freq.u64)));
+    }
+
+
+    /* Nothing more to do if there's no RR packet */
+    if (rr == NULL)
         return;
-        
+
 
     last_loss = sess->stat.tx.loss;
 
     /* Get packet loss */
-    sess->stat.tx.loss = (rtcp->rr.total_lost_2 << 16) +
-                         (rtcp->rr.total_lost_1 << 8) +
-                          rtcp->rr.total_lost_0;
+    sess->stat.tx.loss = (rr->total_lost_2 << 16) +
+                         (rr->total_lost_1 << 8) +
+                          rr->total_lost_0;
+
+    TRACE_((sess->name, "Rx RTCP RR: total_lost_2=%x, 1=%x, 0=%x, lost=%d", 
+            (int)rr->total_lost_2,
+            (int)rr->total_lost_1,
+            (int)rr->total_lost_0,
+            sess->stat.tx.loss));
     
     /* We can't calculate the exact loss period for TX, so just give the
@@ -360 +384 @@
 
     /* Get jitter value in usec */
-    jitter_samp = pj_ntohl(rtcp->rr.jitter);
+    jitter_samp = pj_ntohl(rr->jitter);
     /* Calculate jitter in usec, avoiding overflows */
     if (jitter_samp <= 4294)
@@ -383 +407 @@
 
     /* Can only calculate if LSR and DLSR is present in RR */
-    if (rtcp->rr.lsr && rtcp->rr.dlsr) {
+    if (rr->lsr && rr->dlsr) {
         pj_uint32_t lsr, now, dlsr;
         pj_uint64_t eedelay;
@@ -391 +415 @@
          * resolution 
          */
-        lsr = pj_ntohl(rtcp->rr.lsr);
+        lsr = pj_ntohl(rr->lsr);
 
         /* DLSR is delay since LSR, also in 1/65536 resolution */
-        dlsr = pj_ntohl(rtcp->rr.dlsr);
+        dlsr = pj_ntohl(rr->dlsr);
 
         /* Get current time, and convert to 1/65536 resolution */
@@ -425 +449 @@
             unsigned rtt = (pj_uint32_t)eedelay;
             
-            TRACE_((sess->name, "RTCP RTT is set to %d usec", rtt));
-
-            if (rtt >= 1000000) {
-                pjmedia_rtcp_ntp_rec ntp2;
-                pj_thread_sleep(50);
-                pjmedia_rtcp_get_ntp_time(sess, &ntp2);
-                ntp2.lo = ntp2.lo;
+            /* Check that eedelay value really makes sense. 
+             * We allow up to 30 seconds RTT!
+             */
+            if (eedelay > 30 * 1000 * 1000UL) {
+
+                TRACE_((sess->name, "RTT not making any sense, ignored.."));
+                goto end_rtt_calc;
             }
 
             if (sess->stat.rtt_update_cnt == 0)
                 sess->stat.rtt.min = rtt;
+
+            /* "Normalize" rtt value that is exceptionally high.
+             * For such values, "normalize" the rtt to be three times
+             * the average value.
+             */
+            if (rtt > (sess->stat.rtt.avg*3) && sess->stat.rtt_update_cnt!=0) {
+                unsigned orig_rtt = rtt;
+                rtt = sess->stat.rtt.avg*3;
+                PJ_LOG(5,(sess->name, 
+                          "RTT value %d usec is normalized to %d usec",
+                          orig_rtt, rtt));
+            }
+        
+            TRACE_((sess->name, "RTCP RTT is set to %d usec", rtt));
 
             if (rtt < sess->stat.rtt.min && rtt)
@@ -458 +496 @@
         }
     }
+
+end_rtt_calc:
 
     pj_gettimeofday(&sess->stat.tx.update);
@@ -508 +548 @@
     if (expected >= sess->received)
         sess->stat.rx.loss = expected - sess->received;
+    else
+        sess->stat.rx.loss = 0;
+
     rtcp_pkt->rr.total_lost_2 = (sess->stat.rx.loss >> 16) & 0xFF;
     rtcp_pkt->rr.total_lost_1 = (sess->stat.rx.loss >> 8) & 0xFF;