From 93c6754fc47a3f223424ef7e202eef45262a6cc7 Mon Sep 17 00:00:00 2001
From: ziyue <1213642868@qq.com>
Date: Wed, 20 Oct 2021 11:54:05 +0800
Subject: [PATCH] =?UTF-8?q?=E5=85=BC=E5=AE=B9=E4=B8=80=E4=BA=9B=E4=B8=8D?=
 =?UTF-8?q?=E8=A7=84=E8=8C=83=E7=9A=84rtsp=E6=B5=81?=
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---
 src/Rtcp/Rtcp.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/Rtcp/Rtcp.cpp b/src/Rtcp/Rtcp.cpp
index 707e08e4..2960743f 100644
--- a/src/Rtcp/Rtcp.cpp
+++ b/src/Rtcp/Rtcp.cpp
@@ -264,6 +264,11 @@ string RtcpSR::getNtpStamp() const{
 }
 
 uint64_t RtcpSR::getNtpUnixStampMS() const {
+    if (ntpmsw < 0x83AA7E80) {
+        //ntp时间戳起始时间为1900年，但是utc时间戳起始时间为1970年，两者相差0x83AA7E80秒
+        //ntp时间戳不得早于1970年，否则无法转换为utc时间戳
+        return 0;
+    }
     struct timeval tv;
     tv.tv_sec = ntpmsw - 0x83AA7E80;
     tv.tv_usec = (decltype(tv.tv_usec)) (ntplsw / ((double) (((uint64_t) 1) << 32) * 1.0e-6));