For #307, refine RTC latency from 600ms to 200ms. 4.0.20

README.md

@@ -158,6 +158,7 @@ For previous versions, please read:
 
 ## V4 changes
 
+* v4.0, 2020-04-04, For [#307][bug #307], refine RTC latency from 600ms to 200ms. 4.0.20
 * v4.0, 2020-04-03, For [#307][bug #307], build SRTP with openssl to improve performance. 4.0.19
 * v4.0, 2020-03-31, For [#1500][bug #1500], support push stream by GB28181. 4.0.18
 * v4.0, 2020-03-31, Play stream by WebRTC on iOS/Android/PC browser. 4.0.17

trunk/conf/full.conf

@@ -421,6 +421,14 @@ vhost rtc.vhost.srs.com {
         # default: transcode
         aac         transcode;
     }
+    # whether enable min delay mode for vhost.
+    # For RTC, we recommend to set to on.
+    min_latency     on;
+    play {
+        # set the MW(merged-write) latency in ms.
+        # For RTC, we recommend lower value, such as 0.
+        mw_latency      0;
+    }
 }
 
 #############################################################################################
@@ -444,7 +452,8 @@ vhost scope.vhost.srs.com {
     # 1. disable the publish.mr for vhost.
     # 2. use timeout for cond wait for consumer queue.
     # @see https://github.com/ossrs/srs/issues/257
-    # default: off
+    # default: off (for RTMP/HTTP-FLV)
+    # default: on (for WebRTC)
     min_latency     off;
 
     # whether enable the TCP_NODELAY
@@ -645,7 +654,8 @@ vhost play.srs.com {
         # SRS always set mw on, so we just set the latency value.
         # the latency of stream >= mw_latency + mr_latency
         # the value recomment is [300, 1800]
-        # default: 350
+        # default: 350 (for RTMP/HTTP-FLV)
+        # default: 0 (for WebRTC)
         mw_latency      350;
 
         # the minimal packets send interval in ms,

trunk/src/app/srs_app_config.cpp

@@ -5126,9 +5126,12 @@ srs_utime_t SrsConfig::get_mr_sleep(string vhost)
     return (srs_utime_t)(::atoi(conf->arg0().c_str()) * SRS_UTIME_MILLISECONDS);
 }
 
-srs_utime_t SrsConfig::get_mw_sleep(string vhost)
+srs_utime_t SrsConfig::get_mw_sleep(string vhost, bool is_rtc)
 {
-    static srs_utime_t DEFAULT = SRS_PERF_MW_SLEEP;
+    static srs_utime_t SYS_DEFAULT = SRS_PERF_MW_SLEEP;
+    static srs_utime_t RTC_DEFAULT = 0;
+
+    srs_utime_t DEFAULT = is_rtc? RTC_DEFAULT : SYS_DEFAULT;
 
     SrsConfDirective* conf = get_vhost(vhost);
     if (!conf) {
@@ -5148,19 +5151,28 @@ srs_utime_t SrsConfig::get_mw_sleep(string vhost)
     return (srs_utime_t)(::atoi(conf->arg0().c_str()) * SRS_UTIME_MILLISECONDS);
 }
 
-bool SrsConfig::get_realtime_enabled(string vhost)
+bool SrsConfig::get_realtime_enabled(string vhost, bool is_rtc)
 {
+    static bool SYS_DEFAULT = SRS_PERF_MIN_LATENCY_ENABLED;
+    static bool RTC_DEFAULT = true;
+
+    bool DEFAULT = is_rtc? RTC_DEFAULT : SYS_DEFAULT;
+
     SrsConfDirective* conf = get_vhost(vhost);
     if (!conf) {
-        return SRS_PERF_MIN_LATENCY_ENABLED;
+        return DEFAULT;
     }
     
     conf = conf->get("min_latency");
     if (!conf || conf->arg0().empty()) {
-        return SRS_PERF_MIN_LATENCY_ENABLED;
+        return DEFAULT;
     }
 
+    if (is_rtc) {
+        return SRS_CONF_PERFER_TRUE(conf->arg0());
+    } else {
         return SRS_CONF_PERFER_FALSE(conf->arg0());
+    }
 }
 
 bool SrsConfig::get_tcp_nodelay(string vhost)

trunk/src/app/srs_app_config.hpp

@@ -605,14 +605,14 @@ public:
     // @param vhost, the vhost to get the mr sleep time.
     // TODO: FIXME: add utest for mr config.
     virtual srs_utime_t get_mr_sleep(std::string vhost);
-    // Get the mw sleep time in srs_utime_t for vhost.
+    // Get the mw_latency, mw sleep time in srs_utime_t for vhost.
     // @param vhost, the vhost to get the mw sleep time.
     // TODO: FIXME: add utest for mw config.
-    virtual srs_utime_t get_mw_sleep(std::string vhost);
+    virtual srs_utime_t get_mw_sleep(std::string vhost, bool is_rtc = false);
     // Whether min latency mode enabled.
     // @param vhost, the vhost to get the min_latency.
     // TODO: FIXME: add utest for min_latency.
-    virtual bool get_realtime_enabled(std::string vhost);
+    virtual bool get_realtime_enabled(std::string vhost, bool is_rtc = false);
     // Whether enable tcp nodelay for all clients of vhost.
     virtual bool get_tcp_nodelay(std::string vhost);
     // The minimal send interval in srs_utime_t.

trunk/src/app/srs_app_rtc_conn.cpp

@@ -507,21 +507,31 @@ srs_error_t SrsRtcSenderThread::cycle()
         rtc_session->request.get_stream_url().c_str(), ::getpid(), source->source_id());
 
 	SrsConsumer* consumer = NULL;
+    SrsAutoFree(SrsConsumer, consumer);
     if ((err = source->create_consumer(NULL, consumer)) != srs_success) {
         return srs_error_wrap(err, "rtc create consumer, source url=%s", rtc_session->request.get_stream_url().c_str());
     }
 
-    SrsAutoFree(SrsConsumer, consumer);
+    // TODO: FIXME: Support reload.
+    SrsRequest* req = &rtc_session->request;
+    bool realtime = _srs_config->get_realtime_enabled(req->vhost, true);
+    srs_utime_t mw_sleep = _srs_config->get_mw_sleep(req->vhost, true);
+
+    SrsMessageArray msgs(SRS_PERF_MW_MSGS);
 
     while (true) {
 		if ((err = trd->pull()) != srs_success) {
             return srs_error_wrap(err, "rtc sender thread");
         }
 
-        SrsMessageArray msgs(SRS_PERF_MW_MSGS);
-
 #ifdef SRS_PERF_QUEUE_COND_WAIT
-        consumer->wait(0, SRS_PERF_MW_SLEEP);
+        if (realtime) {
+            // for realtime, min required msgs is 0, send when got one+ msgs.
+            consumer->wait(0, mw_sleep);
+        } else {
+            // for no-realtime, got some msgs then send.
+            consumer->wait(SRS_PERF_MW_MIN_MSGS_FOR_RTC, mw_sleep);
+        }
 #endif
 
         int msg_count = 0;

trunk/src/core/srs_core_performance.hpp

@@ -124,6 +124,7 @@
 #define SRS_PERF_QUEUE_COND_WAIT
 #ifdef SRS_PERF_QUEUE_COND_WAIT
     #define SRS_PERF_MW_MIN_MSGS 8
+    #define SRS_PERF_MW_MIN_MSGS_FOR_RTC 0
 #endif
 /**
  * the default value of vhost for

trunk/src/core/srs_core_version4.hpp

@@ -24,6 +24,6 @@
 #ifndef SRS_CORE_VERSION4_HPP
 #define SRS_CORE_VERSION4_HPP
 
-#define SRS_VERSION4_REVISION 19
+#define SRS_VERSION4_REVISION 20
 
 #endif