diff --git a/src/Rtcp/RtcpFCI.cpp b/src/Rtcp/RtcpFCI.cpp
index cd79db37..725236d4 100644
--- a/src/Rtcp/RtcpFCI.cpp
+++ b/src/Rtcp/RtcpFCI.cpp
@@ -460,7 +460,7 @@ map<uint16_t, std::pair<SymbolStatus, uint32_t/*stamp*/> > FCI_TWCC::getPacketCh
     }
     for (auto &pr : ret) {
         CHECK(ptr <= end);
-        pr.second.second = 250 * getRecvDelta(pr.second.first, ptr, end);
+        pr.second.second = getRecvDelta(pr.second.first, ptr, end);
     }
     return ret;
 }
diff --git a/src/Rtcp/RtcpFCI.h b/src/Rtcp/RtcpFCI.h
index 1389231d..071a3d1b 100644
--- a/src/Rtcp/RtcpFCI.h
+++ b/src/Rtcp/RtcpFCI.h
@@ -350,9 +350,10 @@ public:
     void check(size_t size);
     string dumpString(size_t total_size) const;
     uint16_t getBaseSeq() const;
+    //单位64ms
     uint32_t getReferenceTime() const;
     uint16_t getPacketCount() const;
-    map<uint16_t, std::pair<SymbolStatus, uint32_t/*recv delta 微秒*/> > getPacketChunkList(size_t total_size) const;
+    map<uint16_t, std::pair<SymbolStatus, uint32_t/*recv delta,单位为250us*/> > getPacketChunkList(size_t total_size) const;
 
 private:
     //base sequence number,基础序号,本次反馈的第一个包的序号;也就是RTP扩展头的序列号