diff --git a/trunk/src/app/srs_app_rtc_queue.cpp b/trunk/src/app/srs_app_rtc_queue.cpp
index 3919e385d..21ba6c781 100644
--- a/trunk/src/app/srs_app_rtc_queue.cpp
+++ b/trunk/src/app/srs_app_rtc_queue.cpp
@@ -141,6 +141,14 @@ void SrsRtpRingBuffer::notify_drop_seq(uint16_t seq)
 {
 }
 
+SrsNackOption::SrsNackOption()
+{
+    max_count = 10;
+    max_alive_time = 2 * SRS_UTIME_SECONDS;
+    first_nack_interval = 10 * SRS_UTIME_MILLISECONDS;
+    nack_interval = 400 * SRS_UTIME_MILLISECONDS;
+}
+
 SrsRtpNackInfo::SrsRtpNackInfo()
 {
     generate_time_ = srs_update_system_time();
@@ -148,6 +156,10 @@ SrsRtpNackInfo::SrsRtpNackInfo()
     req_nack_count_ = 0;
 }
 
+bool SrsRtpNackForReceiver::SeqComp::operator()(const uint16_t& low, const uint16_t& high) const {
+    return srs_rtp_seq_distance(low, high) > 0;
+}
+
 SrsRtpNackForReceiver::SrsRtpNackForReceiver(SrsRtpRingBuffer* rtp, size_t queue_size)
 {
     max_queue_size_ = queue_size;
diff --git a/trunk/src/app/srs_app_rtc_queue.hpp b/trunk/src/app/srs_app_rtc_queue.hpp
index 09af76158..ecda676c9 100644
--- a/trunk/src/app/srs_app_rtc_queue.hpp
+++ b/trunk/src/app/srs_app_rtc_queue.hpp
@@ -101,39 +101,31 @@ public:
 
 struct SrsNackOption
 {
-    SrsNackOption()
-    {
-        // Default nack option.
-        max_count = 10;
-        max_alive_time = 2 * SRS_UTIME_SECONDS;
-        first_nack_interval = 10 * SRS_UTIME_MILLISECONDS;
-        nack_interval = 400 * SRS_UTIME_MILLISECONDS;
-    }
     int max_count;
     srs_utime_t max_alive_time;
     int64_t first_nack_interval;
     int64_t nack_interval;
+
+    SrsNackOption();
 };
 
 struct SrsRtpNackInfo
 {
-    SrsRtpNackInfo();
-
     // Use to control the time of first nack req and the life of seq.
     srs_utime_t generate_time_;
     // Use to control nack interval.
     srs_utime_t pre_req_nack_time_;
     // Use to control nack times.
     int req_nack_count_;
+
+    SrsRtpNackInfo();
 };
 
 class SrsRtpNackForReceiver
 {
 private:
     struct SeqComp {
-        bool operator()(const uint16_t& low, const uint16_t& high) const {
-            return srs_rtp_seq_distance(low, high) > 0;
-        }
+        bool operator()(const uint16_t& low, const uint16_t& high) const;
     };
 private:
     // Nack queue, seq order, oldest to newest.