From a0dedba2ab9239fcc66a1ae7dfcef824ea0f38b6 Mon Sep 17 00:00:00 2001
From: winlin <winlin@vip.126.com>
Date: Wed, 2 Sep 2020 11:30:20 +0800
Subject: [PATCH] RTC: Fix NACK bug

---
 trunk/src/app/srs_app_rtc_conn.cpp  | 57 ++++++++++-------------------
 trunk/src/app/srs_app_rtc_queue.cpp |  4 +-
 trunk/src/app/srs_app_rtc_queue.hpp |  3 +-
 3 files changed, 24 insertions(+), 40 deletions(-)

diff --git a/trunk/src/app/srs_app_rtc_conn.cpp b/trunk/src/app/srs_app_rtc_conn.cpp
index 45ee5adda..3829e1287 100644
--- a/trunk/src/app/srs_app_rtc_conn.cpp
+++ b/trunk/src/app/srs_app_rtc_conn.cpp
@@ -2078,46 +2078,29 @@ srs_error_t SrsRtcConnection::send_rtcp(char *data, int nb_data)
 
 void SrsRtcConnection::check_send_nacks(SrsRtpNackForReceiver* nack, uint32_t ssrc, uint32_t& sent_nacks)
 {
-    // @see: https://tools.ietf.org/html/rfc4585#section-6.1
-    vector<uint16_t> nack_seqs;
-    nack->get_nack_seqs(nack_seqs);
+    SrsRtcpNack rtcpNack(ssrc);
 
-    vector<uint16_t>::iterator iter = nack_seqs.begin();
-    while (iter != nack_seqs.end()) {
-        char buf[kRtpPacketSize];
-        SrsBuffer stream(buf, sizeof(buf));
-        // FIXME: Replace magic number.
-        stream.write_1bytes(0x81);
-        stream.write_1bytes(kRtpFb);
-        stream.write_2bytes(3);
-        stream.write_4bytes(ssrc); // TODO: FIXME: Should be 1?
-        stream.write_4bytes(ssrc); // TODO: FIXME: Should be 0?
-        uint16_t pid = *iter;
-        uint16_t blp = 0;
-        while (iter + 1 != nack_seqs.end() && (*(iter + 1) - pid <= 15)) {
-            blp |= (1 << (*(iter + 1) - pid - 1));
-            ++iter;
-        }
+    rtcpNack.set_media_ssrc(ssrc);
+    nack->get_nack_seqs(rtcpNack);
 
-        stream.write_2bytes(pid);
-        stream.write_2bytes(blp);
-
-        if (_srs_blackhole->blackhole) {
-            _srs_blackhole->sendto(stream.data(), stream.pos());
-        }
-
-        char protected_buf[kRtpPacketSize];
-        int nb_protected_buf = stream.pos();
-
-        // FIXME: Merge nack rtcp into one packets.
-        if (transport_->protect_rtcp(stream.data(), protected_buf, nb_protected_buf) == srs_success) {
-            // TODO: FIXME: Check error.
-            sendonly_skt->sendto(protected_buf, nb_protected_buf, 0);
-        }
-
-        ++iter;
-        ++sent_nacks;
+    sent_nacks = rtcpNack.get_lost_sns().size();
+    if(!sent_nacks){
+        return;
     }
+
+    char buf[kRtcpPacketSize];
+    SrsBuffer stream(buf, sizeof(buf));
+
+    // TODO: FIXME: Check error.
+    rtcpNack.encode(&stream);
+
+    // TODO: FIXME: Check error.
+    char protected_buf[kRtpPacketSize];
+    int nb_protected_buf = stream.pos();
+    transport_->protect_rtcp(stream.data(), protected_buf, nb_protected_buf);
+
+    // TODO: FIXME: Check error.
+    sendonly_skt->sendto(protected_buf, nb_protected_buf, 0);
 }
 
 srs_error_t SrsRtcConnection::send_rtcp_rr(uint32_t ssrc, SrsRtpRingBuffer* rtp_queue, const uint64_t& last_send_systime, const SrsNtp& last_send_ntp)
diff --git a/trunk/src/app/srs_app_rtc_queue.cpp b/trunk/src/app/srs_app_rtc_queue.cpp
index f569e178c..3e562b6e8 100644
--- a/trunk/src/app/srs_app_rtc_queue.cpp
+++ b/trunk/src/app/srs_app_rtc_queue.cpp
@@ -230,7 +230,7 @@ void SrsRtpNackForReceiver::check_queue_size()
     }
 }
 
-void SrsRtpNackForReceiver::get_nack_seqs(vector<uint16_t>& seqs)
+void SrsRtpNackForReceiver::get_nack_seqs(SrsRtcpNack& seqs)
 {
     // TODO: FIXME: Use packet as tick count, not clock.
     srs_utime_t now = srs_update_system_time();
@@ -261,7 +261,7 @@ void SrsRtpNackForReceiver::get_nack_seqs(vector<uint16_t>& seqs)
         if (now - nack_info.pre_req_nack_time_ >= opts_.nack_interval && nack_info.req_nack_count_ <= opts_.max_count) {
             ++nack_info.req_nack_count_;
             nack_info.pre_req_nack_time_ = now;
-            seqs.push_back(seq);
+            seqs.add_lost_sn(seq);
         }
 
         ++iter;
diff --git a/trunk/src/app/srs_app_rtc_queue.hpp b/trunk/src/app/srs_app_rtc_queue.hpp
index be945dd25..c45af2a21 100644
--- a/trunk/src/app/srs_app_rtc_queue.hpp
+++ b/trunk/src/app/srs_app_rtc_queue.hpp
@@ -31,6 +31,7 @@
 #include <map>
 
 #include <srs_kernel_rtc_rtp.hpp>
+#include <srs_kernel_rtc_rtcp.hpp>
 
 class SrsRtpPacket2;
 class SrsRtpQueue;
@@ -132,7 +133,7 @@ public:
     SrsRtpNackInfo* find(uint16_t seq);
     void check_queue_size();
 public:
-    void get_nack_seqs(std::vector<uint16_t>& seqs);
+    void get_nack_seqs(SrsRtcpNack& seqs);
 public:
     void update_rtt(int rtt);
 private: