Debugging: Drop the specified N original SRTP packet for testing NACK.

trunk/auto/auto_headers.sh

@@ -239,6 +239,12 @@ else
     srs_undefine_macro "SRS_DEBUG_STATS" $SRS_AUTO_HEADERS_H
 fi
 
+if [[ $SRS_DEBUG_NACK_DROP == YES ]]; then
+    srs_define_macro "SRS_DEBUG_NACK_DROP" $SRS_AUTO_HEADERS_H
+else
+    srs_undefine_macro "SRS_DEBUG_NACK_DROP" $SRS_AUTO_HEADERS_H
+fi
+
 # prefix
 echo "" >> $SRS_AUTO_HEADERS_H
 echo "#define SRS_PREFIX \"${SRS_PREFIX}\"" >> $SRS_AUTO_HEADERS_H

trunk/auto/options.sh

@@ -131,6 +131,7 @@ SRS_NASM=YES
 SRS_SRTP_ASM=YES
 SRS_DEBUG=NO
 SRS_DEBUG_STATS=NO
+SRS_DEBUG_NACK_DROP=NO
 
 #####################################################################################
 function apply_system_options() {
@@ -244,6 +245,7 @@ Experts:
   --build-tag=<TAG>         Set the build object directory suffix.
   --debug=on|off            Whether enable the debug code, may hurt performance. Default: $(value2switch $SRS_DEBUG)
   --debug-stats=on|off      Whether enable the debug stats, may hurt performance. Default: $(value2switch $SRS_DEBUG_STATS)
+  --debug-nack-drop=on|off  Whether enable the debug nack drop, always drop the first number N packet. Default: $(value2switch $SRS_DEBUG_NACK_DROP)
   --gcov=on|off             Whether enable the GCOV for coverage. Default: $(value2switch $SRS_GCOV)
   --log-verbose=on|off      Whether enable the log verbose level. Default: $(value2switch $SRS_LOG_VERBOSE)
   --log-info=on|off         Whether enable the log info level. Default: $(value2switch $SRS_LOG_INFO)
@@ -388,6 +390,7 @@ function parse_user_option() {
         --log-level_v2)                 SRS_LOG_LEVEL_V2=$(switch2value $value) ;;
         --debug)                        SRS_DEBUG=$(switch2value $value) ;;
         --debug-stats)                  SRS_DEBUG_STATS=$(switch2value $value) ;;
+        --debug-nack-drop)              SRS_DEBUG_NACK_DROP=$(switch2value $value) ;;
 
         --cross-build)                  SRS_CROSS_BUILD=YES         ;;
         --generic-linux)                SRS_GENERIC_LINUX=$(switch2value $value) ;;
@@ -683,6 +686,7 @@ function regenerate_options() {
     SRS_AUTO_CONFIGURE="${SRS_AUTO_CONFIGURE} --apm=$(value2switch $SRS_APM)"
     SRS_AUTO_CONFIGURE="${SRS_AUTO_CONFIGURE} --debug=$(value2switch $SRS_DEBUG)"
     SRS_AUTO_CONFIGURE="${SRS_AUTO_CONFIGURE} --debug-stats=$(value2switch $SRS_DEBUG_STATS)"
+    SRS_AUTO_CONFIGURE="${SRS_AUTO_CONFIGURE} --debug-nack-drop=$(value2switch $SRS_DEBUG_NACK_DROP)"
     SRS_AUTO_CONFIGURE="${SRS_AUTO_CONFIGURE} --cross-build=$(value2switch $SRS_CROSS_BUILD)"
     SRS_AUTO_CONFIGURE="${SRS_AUTO_CONFIGURE} --sanitizer=$(value2switch $SRS_SANITIZER)"
     SRS_AUTO_CONFIGURE="${SRS_AUTO_CONFIGURE} --sanitizer-static=$(value2switch $SRS_SANITIZER_STATIC)"

trunk/src/app/srs_app_rtc_network.cpp

@@ -261,6 +261,21 @@ srs_error_t SrsRtcUdpNetwork::on_rtp(char* data, int nb_data)
 {
     srs_error_t err = srs_success;
 
+#ifdef SRS_NACK_DEBUG_DROP_ENABLED
+    static int nn_pkts = 0;
+    bool drop = false;
+    uint32_t ssrc = srs_rtp_fast_parse_ssrc(data, nb_data);
+    uint16_t seq = srs_rtp_fast_parse_seq(data, nb_data);
+    uint8_t pt = srs_rtp_fast_parse_pt(data, nb_data);
+    if (pt && ssrc && pt == SRS_NACK_DEBUG_DROP_PACKET_PT && (nn_pkts++) < 100) {
+        drop = (nn_pkts == SRS_NACK_DEBUG_DROP_PACKET_N);
+        srs_trace(">>> #%d%s rtp seq=%u, pt=%u, ssrc=%u", nn_pkts, drop ? " (dropped)" : "", seq, pt, ssrc);
+    }
+    if (drop) {
+        return err;
+    }
+#endif
+
     // Update stat when we received data.
     delta_->add_delta(nb_data, 0);
 

trunk/src/app/srs_app_rtc_source.cpp

@@ -2757,6 +2757,9 @@ srs_error_t SrsRtcRecvTrack::on_nack(SrsRtpPacket** ppkt)
     if (nack_info) {
         // seq had been received.
         nack_receiver_->remove(seq);
+#ifdef SRS_NACK_DEBUG_DROP_ENABLED
+        srs_trace("NACK: recovered seq=%u", seq);
+#endif
         return err;
     }
 

trunk/src/kernel/srs_kernel_rtc_rtp.cpp

@@ -55,6 +55,13 @@ uint32_t srs_rtp_fast_parse_ssrc(char* buf, int size)
     pp[0] = *p++;
     return value;
 }
+uint16_t srs_rtp_fast_parse_seq(char* buf, int size)
+{
+    if (size < 4) {
+        return 0;
+    }
+    return ((uint8_t)buf[2] << 8) | (uint8_t)buf[3];
+}
 uint8_t srs_rtp_fast_parse_pt(char* buf, int size)
 {
     if (size < 12) {

trunk/src/kernel/srs_kernel_rtc_rtp.hpp

@@ -16,6 +16,16 @@
 #include <list>
 #include <vector>
 
+// Indicates whether to enable debugging for NACK. If enabled, the specified PT(109) 
+// video packet will always be dropped. You can use this option to verify the NACK 
+// logic. Note that you should restart SRS after each test, as a global variable 
+// controls the debugging.
+#ifdef SRS_DEBUG_NACK_DROP
+#define SRS_NACK_DEBUG_DROP_ENABLED
+#endif
+#define SRS_NACK_DEBUG_DROP_PACKET_PT 109
+#define SRS_NACK_DEBUG_DROP_PACKET_N 3
+
 class SrsRtpPacket;
 
 // The RTP packet max size, should never exceed this size.
@@ -50,6 +60,7 @@ class SrsRtpExtensionTypes;
 
 // Fast parse the SSRC from RTP packet. Return 0 if invalid.
 uint32_t srs_rtp_fast_parse_ssrc(char* buf, int size);
+uint16_t srs_rtp_fast_parse_seq(char* buf, int size);
 uint8_t srs_rtp_fast_parse_pt(char* buf, int size);
 srs_error_t srs_rtp_fast_parse_twcc(char* buf, int size, uint8_t twcc_id, uint16_t& twcc_sn);