RTC: Improve NACK efficiency

trunk/src/app/srs_app_rtc_conn.cpp

@@ -1125,6 +1125,13 @@ srs_error_t SrsRtcPublishStream::do_on_rtp(char* plaintext, int nb_plaintext)
         return srs_error_new(ERROR_RTC_RTP, "unknown ssrc=%u", ssrc);
     }
 
+    // Check then send NACK every each RTP packet, to make it more efficient.
+    // For example, NACK of video track maybe triggered by audio RTP packets.
+    if ((err = check_send_nacks()) != srs_success) {
+        srs_warn("ignore nack err %s", srs_error_desc(err).c_str());
+        srs_freep(err);
+    }
+
     if (_srs_rtc_hijacker) {
         // TODO: FIXME: copy pkt by hijacker itself
         if ((err = _srs_rtc_hijacker->on_rtp_packet(session_, this, req, pkt->copy())) != srs_success) {
@@ -1135,6 +1142,27 @@ srs_error_t SrsRtcPublishStream::do_on_rtp(char* plaintext, int nb_plaintext)
     return err;
 }
 
+srs_error_t SrsRtcPublishStream::check_send_nacks()
+{
+    srs_error_t err = srs_success;
+
+    for (int i = 0; i < (int)video_tracks_.size(); ++i) {
+        SrsRtcVideoRecvTrack* track = video_tracks_.at(i);
+        if ((err = track->check_send_nacks()) != srs_success) {
+            return srs_error_wrap(err, "video track=%s", track->get_track_id().c_str());
+        }
+    }
+
+    for (int i = 0; i < (int)audio_tracks_.size(); ++i) {
+        SrsRtcAudioRecvTrack* track = audio_tracks_.at(i);
+        if ((err = track->check_send_nacks()) != srs_success) {
+            return srs_error_wrap(err, "audio track=%s", track->get_track_id().c_str());
+        }
+    }
+
+    return err;
+}
+
 void SrsRtcPublishStream::on_before_decode_payload(SrsRtpPacket2* pkt, SrsBuffer* buf, ISrsRtpPayloader** ppayload)
 {
     // No payload, ignore.

trunk/src/app/srs_app_rtc_conn.hpp

@@ -314,6 +314,7 @@ public:
     srs_error_t on_rtp(char* buf, int nb_buf);
 private:
     srs_error_t do_on_rtp(char* plaintext, int nb_plaintext);
+    srs_error_t check_send_nacks();
 public:
     virtual void on_before_decode_payload(SrsRtpPacket2* pkt, SrsBuffer* buf, ISrsRtpPayloader** ppayload);
 private:

trunk/src/app/srs_app_rtc_source.cpp

@@ -1719,6 +1719,18 @@ srs_error_t SrsRtcRecvTrack::on_nack(SrsRtpPacket2* pkt)
     return err;
 }
 
+srs_error_t SrsRtcRecvTrack::check_send_nacks()
+{
+    srs_error_t err = srs_success;
+
+    uint32_t sent_nacks = 0;
+    uint32_t timeout_nacks = 0;
+    session_->check_send_nacks(nack_receiver_, track_desc_->ssrc_, sent_nacks);
+    statistic_->nacks += sent_nacks;
+
+    return err;
+}
+
 SrsRtcAudioRecvTrack::SrsRtcAudioRecvTrack(SrsRtcConnection* session, SrsRtcTrackDescription* track_desc)
     : SrsRtcRecvTrack(session, track_desc, true)
 {

trunk/src/app/srs_app_rtc_source.hpp

@@ -501,6 +501,7 @@ protected:
     srs_error_t on_nack(SrsRtpPacket2* pkt);
 public:
     virtual srs_error_t on_rtp(SrsRtcStream* source, SrsRtpPacket2* pkt) = 0;
+    virtual srs_error_t check_send_nacks();
 };
 
 class SrsRtcAudioRecvTrack : public SrsRtcRecvTrack