Changeset 397

Timestamp:

Apr 9, 2006 10:42:51 AM (19 years ago)

Author:

bennylp

Message:

Added code in RTCP to handle PerformanceQueryCounter? bug on Win32

Location:

pjproject/trunk/pjmedia

Files:

• include/pjmedia/rtcp.h (modified) (2 diffs)
• src/pjmedia/rtcp.c (modified) (8 diffs)
• src/pjmedia/stream.c (modified) (1 diff)

pjproject/trunk/pjmedia/include/pjmedia/rtcp.h

@@ -230 +230 @@
     pj_int32_t              transit;    /**< Rel transit time for prev pkt  */
     pj_uint32_t             jitter;     /**< Scaled jitter                  */
+    pj_time_val             tv_base;    /**< Base time, in seconds.         */
+    pj_timestamp            ts_base;    /**< Base system timestamp.         */
     pj_timestamp            ts_freq;    /**< System timestamp frequency.    */
 
@@ -260 +262 @@
 
 /**
+ * Utility function to retrieve current NTP timestamp.
+ *
+ * @param sess              RTCP session.
+ * @param ntp               NTP record.
+ *
+ * @return                  PJ_SUCCESS on success.
+ */
+PJ_DEF(pj_status_t) pjmedia_rtcp_get_ntp_time(const pjmedia_rtcp_session *sess,
+                                              pjmedia_rtcp_ntp_rec *ntp);
+
+
+/**
  * Deinitialize RTCP session.
  *

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

@@ -35 +35 @@
 #endif
 
+
+
 #if 0
 #   define TRACE_(x)    PJ_LOG(3,x)
@@ -41 +43 @@
 #endif
 
+
 /*
  * Get NTP time.
  */
-static void rtcp_get_ntp_time(const pjmedia_rtcp_session *sess, 
-                              struct pjmedia_rtcp_ntp_rec *ntp)
-{
-    pj_time_val tv;
+PJ_DEF(pj_status_t) pjmedia_rtcp_get_ntp_time(const pjmedia_rtcp_session *sess,
+                                              pjmedia_rtcp_ntp_rec *ntp)
+{
+/* Seconds between 1900-01-01 to 1970-01-01 */
+#define NTP_DIFF    ((70 * 365 + 17) * 86400UL)
     pj_timestamp ts;
-
-    pj_gettimeofday(&tv);
-    pj_get_timestamp(&ts);
-    
+    pj_status_t status;
+
+    status = pj_get_timestamp(&ts);
+
     /* Fill up the high 32bit part */
-    ntp->hi = tv.sec;
-    
-    /* Calculate second fractions */
+    ntp->hi = (pj_uint32_t)((ts.u64 - sess->ts_base.u64) / sess->ts_freq.u64)
+              + sess->tv_base.sec + NTP_DIFF;
+
+    /* Calculate seconds fractions */
     ts.u64 %= sess->ts_freq.u64;
+    pj_assert(ts.u64 < sess->ts_freq.u64);
     ts.u64 = (ts.u64 << 32) / sess->ts_freq.u64;
 
     /* Fill up the low 32bit part */
     ntp->lo = ts.u32.lo;
+
+
+#if (defined(PJ_WIN32) && PJ_WIN32!=0) || \
+    (defined(PJ_WIN32_WINCE) && PJ_WIN32_WINCE!=0)
+
+    /* On Win32, since we use QueryPerformanceCounter() as the backend
+     * timestamp API, we need to protect against this bug:
+     *   Performance counter value may unexpectedly leap forward
+     *   http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q274323
+     */
+    {
+        /*
+         * Compare elapsed time reported by timestamp with actual elapsed 
+         * time. If the difference is too excessive, then we use system
+         * time instead.
+         */
+
+        /* MIN_DIFF needs to be large enough so that "normal" diff caused
+         * by system activity or context switch doesn't trigger the time
+         * correction.
+         */
+        enum { MIN_DIFF = 400 };
+
+        pj_time_val ts_time, elapsed, diff;
+
+        pj_gettimeofday(&elapsed);
+
+        ts_time.sec = ntp->hi - sess->tv_base.sec - NTP_DIFF;
+        ts_time.msec = (long)(ntp->lo * 1000.0 / 0xFFFFFFFF);
+
+        PJ_TIME_VAL_SUB(elapsed, sess->tv_base);
+
+        if (PJ_TIME_VAL_LT(ts_time, elapsed)) {
+            diff = elapsed;
+            PJ_TIME_VAL_SUB(diff, ts_time);
+        } else {
+            diff = ts_time;
+            PJ_TIME_VAL_SUB(diff, elapsed);
+        }
+
+        if (PJ_TIME_VAL_MSEC(diff) >= MIN_DIFF) {
+
+            TRACE_((THIS_FILE, "NTP timestamp corrected by %d ms",
+                    PJ_TIME_VAL_MSEC(diff)));
+
+
+            ntp->hi = elapsed.sec + sess->tv_base.sec + NTP_DIFF;
+            ntp->lo = (elapsed.msec * 65536 / 1000) << 16;
+        }
+
+    }
+#endif
+
+    return status;
 }
 
@@ -91 +151 @@
     rtcp_pkt->sr.ssrc = pj_htonl(ssrc);
     
-    /* Get timestamp frequency */
+    /* Get time and timestamp base and frequency */
+    pj_gettimeofday(&sess->tv_base);
+    pj_get_timestamp(&sess->ts_base);
     pj_get_timestamp_freq(&sess->ts_freq);
 
@@ -208 +270 @@
 {
     const struct pjmedia_rtcp_pkt *rtcp = pkt;
+    pj_uint32_t last_loss, jitter_samp, jitter;
 
     /* Must at least contain SR */
@@ -219 +282 @@
     pj_get_timestamp(&sess->rx_lsr_time);
 
-    TRACE_((THIS_FILE, "Rx RTCP SR: ntp-ts=%p, time=%p", 
+    TRACE_((THIS_FILE, "Rx RTCP SR: ntp_ts=%p", 
             sess->rx_lsr,
             (pj_uint32_t)(sess->rx_lsr_time.u64*65536/sess->ts_freq.u64)));
 
-    /* Calculate RTT if it has RR */
-    if (size >= sizeof(pjmedia_rtcp_pkt)) {
+    /* Nothing more to do if this is an SR only RTCP packet */
+    if (size < sizeof(pjmedia_rtcp_pkt))
+        return;
         
-        pj_uint32_t last_loss, jitter_samp, jitter;
-
-        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;
+
+    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;
+    
+    /* We can't calculate the exact loss period for TX, so just give the
+     * best estimation.
+     */
+    if (sess->stat.tx.loss > last_loss) {
+        unsigned period;
+
+        /* Loss period in msec */
+        period = (sess->stat.tx.loss - last_loss) * sess->pkt_size *
+                 1000 / sess->clock_rate;
+
+        /* Loss period in usec */
+        period *= 1000;
+
+        if (sess->stat.tx.update_cnt==0||sess->stat.tx.loss_period.min==0)
+            sess->stat.tx.loss_period.min = period;
+        if (period < sess->stat.tx.loss_period.min)
+            sess->stat.tx.loss_period.min = period;
+        if (period > sess->stat.tx.loss_period.max)
+            sess->stat.tx.loss_period.max = period;
+
+        sess->stat.tx.loss_period.avg = 
+            (sess->stat.tx.loss_period.avg*sess->stat.tx.update_cnt+period)
+            / (sess->stat.tx.update_cnt + 1);
+        sess->stat.tx.loss_period.last = period;
+    }
+
+    /* Get jitter value in usec */
+    jitter_samp = pj_ntohl(rtcp->rr.jitter);
+    /* Calculate jitter in usec, avoiding overflows */
+    if (jitter_samp <= 4294)
+        jitter = jitter_samp * 1000000 / sess->clock_rate;
+    else {
+        jitter = jitter_samp * 1000 / sess->clock_rate;
+        jitter *= 1000;
+    }
+
+    /* Update jitter statistics */
+    if (sess->stat.tx.update_cnt == 0)
+        sess->stat.tx.jitter.min = jitter;
+    if (jitter < sess->stat.tx.jitter.min && jitter)
+        sess->stat.tx.jitter.min = jitter;
+    if (jitter > sess->stat.tx.jitter.max)
+        sess->stat.tx.jitter.max = jitter;
+    sess->stat.tx.jitter.avg = 
+        (sess->stat.tx.jitter.avg * sess->stat.tx.update_cnt + jitter) /
+        (sess->stat.tx.update_cnt + 1);
+    sess->stat.tx.jitter.last = jitter;
+
+
+    /* Can only calculate if LSR and DLSR is present in RR */
+    if (rtcp->rr.lsr && rtcp->rr.dlsr) {
+        pj_uint32_t lsr, now, dlsr;
+        pj_uint64_t eedelay;
+        pjmedia_rtcp_ntp_rec ntp;
+
+        /* LSR is the middle 32bit of NTP. It has 1/65536 second 
+         * resolution 
+         */
+        lsr = pj_ntohl(rtcp->rr.lsr);
+
+        /* DLSR is delay since LSR, also in 1/65536 resolution */
+        dlsr = pj_ntohl(rtcp->rr.dlsr);
+
+        /* Get current time, and convert to 1/65536 resolution */
+        pjmedia_rtcp_get_ntp_time(sess, &ntp);
+        now = ((ntp.hi & 0xFFFF) << 16) + (ntp.lo >> 16);
+
+        /* End-to-end delay is (now-lsr-dlsr) */
+        eedelay = now - lsr - dlsr;
+
+        /* Convert end to end delay to usec (keeping the calculation in
+         * 64bit space)::
+         *   sess->ee_delay = (eedelay * 1000) / 65536;
+         */
+        if (eedelay < 4294) {
+            eedelay = (eedelay * 1000000) >> 16;
+        } else {
+            eedelay = (eedelay * 1000) >> 16;
+            eedelay *= 1000;
+        }
+
+        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));
         
-        /* We can't calculate the exact loss period for TX, so just give the
-         * best estimation.
-         */
-        if (sess->stat.tx.loss > last_loss) {
-            unsigned period;
-
-            /* Loss period in msec */
-            period = (sess->stat.tx.loss - last_loss) * sess->pkt_size *
-                     1000 / sess->clock_rate;
-
-            /* Loss period in usec */
-            period *= 1000;
-
-            if (sess->stat.tx.update_cnt==0||sess->stat.tx.loss_period.min==0)
-                sess->stat.tx.loss_period.min = period;
-            if (period < sess->stat.tx.loss_period.min)
-                sess->stat.tx.loss_period.min = period;
-            if (period > sess->stat.tx.loss_period.max)
-                sess->stat.tx.loss_period.max = period;
-
-            sess->stat.tx.loss_period.avg = 
-                (sess->stat.tx.loss_period.avg*sess->stat.tx.update_cnt+period)
-                / (sess->stat.tx.update_cnt + 1);
-            sess->stat.tx.loss_period.last = period;
+        /* Only save calculation if "now" is greater than lsr, or
+         * otherwise rtt will be invalid 
+         */
+        if (now-dlsr >= lsr) {
+            unsigned rtt = (pj_uint32_t)eedelay;
+            
+            TRACE_((THIS_FILE, "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;
+            }
+
+            if (sess->stat.rtt_update_cnt == 0)
+                sess->stat.rtt.min = rtt;
+
+            if (rtt < sess->stat.rtt.min && rtt)
+                sess->stat.rtt.min = rtt;
+            if (rtt > sess->stat.rtt.max)
+                sess->stat.rtt.max = rtt;
+
+            sess->stat.rtt.avg = 
+                (sess->stat.rtt.avg * sess->stat.rtt_update_cnt + rtt) / 
+                (sess->stat.rtt_update_cnt + 1);
+
+            sess->stat.rtt.last = rtt;
+            sess->stat.rtt_update_cnt++;
+
+        } else {
+            PJ_LOG(5, (THIS_FILE, "Internal NTP clock skew detected: "
+                                   "lsr=%p, now=%p, dlsr=%p (%d:%03dms), "
+                                   "diff=%d",
+                                   lsr, now, dlsr, dlsr/65536,
+                                   (dlsr%65536)*1000/65536,
+                                   dlsr-(now-lsr)));
         }
-
-        /* Get jitter value in usec */
-        jitter_samp = pj_ntohl(rtcp->rr.jitter);
-        /* Calculate jitter in usec, avoiding overflows */
-        if (jitter_samp <= 4294)
-            jitter = jitter_samp * 1000000 / sess->clock_rate;
-        else {
-            jitter = jitter_samp * 1000 / sess->clock_rate;
-            jitter *= 1000;
-        }
-
-        /* Update jitter statistics */
-        if (sess->stat.tx.update_cnt == 0)
-            sess->stat.tx.jitter.min = jitter;
-        if (jitter < sess->stat.tx.jitter.min && jitter)
-            sess->stat.tx.jitter.min = jitter;
-        if (jitter > sess->stat.tx.jitter.max)
-            sess->stat.tx.jitter.max = jitter;
-        sess->stat.tx.jitter.avg = 
-            (sess->stat.tx.jitter.avg * sess->stat.tx.update_cnt + jitter) /
-            (sess->stat.tx.update_cnt + 1);
-        sess->stat.tx.jitter.last = jitter;
-
-
-        /* Can only calculate if LSR and DLSR is present in RR */
-        if (rtcp->rr.lsr && rtcp->rr.dlsr) {
-            pj_uint32_t lsr, now, dlsr;
-            pj_uint64_t eedelay;
-            pjmedia_rtcp_ntp_rec ntp;
-
-            /* LSR is the middle 32bit of NTP. It has 1/65536 second 
-             * resolution 
-             */
-            lsr = pj_ntohl(rtcp->rr.lsr);
-
-            /* DLSR is delay since LSR, also in 1/65536 resolution */
-            dlsr = pj_ntohl(rtcp->rr.dlsr);
-
-            /* Get current time, and convert to 1/65536 resolution */
-            rtcp_get_ntp_time(sess, &ntp);
-            now = ((ntp.hi & 0xFFFF) << 16) + 
-                  (ntp.lo >> 16);
-
-            /* End-to-end delay is (now-lsr-dlsr) */
-            eedelay = now - lsr - dlsr;
-
-            /* Convert end to end delay to usec (keeping the calculation in
-             * 64bit space)::
-             *   sess->ee_delay = (eedelay * 1000) / 65536;
-             */
-            eedelay = (eedelay * 1000000) >> 16;
-
-            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));
-            
-            /* Only save calculation if "now" is greater than lsr, or
-             * otherwise rtt will be invalid 
-             */
-            if (now-dlsr >= lsr) {
-                unsigned rtt = (pj_uint32_t)eedelay;
-                
-                if (sess->stat.rtt_update_cnt == 0)
-                    sess->stat.rtt.min = rtt;
-
-                if (rtt < sess->stat.rtt.min && rtt)
-                    sess->stat.rtt.min = rtt;
-                if (rtt > sess->stat.rtt.max)
-                    sess->stat.rtt.max = rtt;
-
-                sess->stat.rtt.avg = 
-                    (sess->stat.rtt.avg * sess->stat.rtt_update_cnt + rtt) / 
-                    (sess->stat.rtt_update_cnt + 1);
-
-                sess->stat.rtt.last = rtt;
-                sess->stat.rtt_update_cnt++;
-
-            } else {
-                PJ_LOG(3, (THIS_FILE, "Internal NTP clock skew detected: "
-                                       "lsr=%p, now=%p, dlsr=%p (%d:%03dms), "
-                                       "diff=%d",
-                                       lsr, now, dlsr, dlsr/65536,
-                                       (dlsr%65536)*1000/65536,
-                                       dlsr-(now-lsr)));
-            }
-        }
-
-        pj_gettimeofday(&sess->stat.tx.update);
-        sess->stat.tx.update_cnt++;
-    }
+    }
+
+    pj_gettimeofday(&sess->stat.tx.update);
+    sess->stat.tx.update_cnt++;
 }
 
@@ -361 +436 @@
     pj_uint32_t jitter_samp, jitter;
     pjmedia_rtcp_pkt *rtcp_pkt = &sess->rtcp_pkt;
+    pj_timestamp ts_now;
     pjmedia_rtcp_ntp_rec ntp;
     
@@ -417 +493 @@
     
     /* Get current NTP time. */
-    rtcp_get_ntp_time(sess, &ntp);
+    pj_get_timestamp(&ts_now);
+    pjmedia_rtcp_get_ntp_time(sess, &ntp);
     
     /* Fill in NTP timestamp in SR. */
     rtcp_pkt->sr.ntp_sec = pj_htonl(ntp.hi);
     rtcp_pkt->sr.ntp_frac = pj_htonl(ntp.lo);
-    
+
+    TRACE_((THIS_FILE, "TX RTCP SR: ntp_ts=%p", 
+                       ((ntp.hi & 0xFFFF) << 16) + ((ntp.lo & 0xFFFF0000) 
+                            >> 16)));
+
     if (sess->rx_lsr_time.u64 == 0 || sess->rx_lsr == 0) {
         rtcp_pkt->rr.lsr = 0;
@@ -443 +524 @@
            DLSR is Delay since Last SR, in 1/65536 seconds.
          */
-        pj_get_timestamp(&ts);
+        ts.u64 = ts_now.u64;
 
         /* Convert interval to 1/65536 seconds value */

pjproject/trunk/pjmedia/src/pjmedia/stream.c

@@ -31 +31 @@
 #include <pj/os.h>
 #include <pj/pool.h>
+#include <pj/rand.h>
 #include <pj/sock_select.h>
 #include <pj/string.h>      /* memcpy() */