fix #257, server latency is 0.1s+, the bottleneck is encoder. 2.0.71

@@ -786,6 +786,10 @@ The latency between encoder and player with realtime config(
 </tr>
 </table>
 
+We use FMLE as encoder to benchmark. The latency of server is 0.1s+, 
+and the bottleneck is on the encoder. For more information, read 
+[bug #257](https://github.com/winlinvip/simple-rtmp-server/issues/257#issuecomment-66864413).
+
 ## Architecture
 
 SRS always use the most simple architecture to support complex transaction.

@@ -589,11 +589,12 @@ int SrsRtmpConn::do_playing(SrsSource* source, SrsQueueRecvThread* trd)
     bool user_specified_duration_to_stop = (req->duration > 0);
     int64_t starttime = -1;
     
+    // setup the realtime.
+    realtime = _srs_config->get_realtime_enabled(req->vhost);
     // setup the mw config.
     // when mw_sleep changed, resize the socket send buffer.
     mw_enabled = true;
     change_mw_sleep(_srs_config->get_mw_sleep_ms(req->vhost));
-    realtime = _srs_config->get_realtime_enabled(req->vhost);
     
     while (true) {
         // to use isolate thread to recv, can improve about 33% performance.
@@ -642,34 +643,40 @@ int SrsRtmpConn::do_playing(SrsSource* source, SrsQueueRecvThread* trd)
             return ret;
         }
 
-#ifdef SRS_PERF_QUEUE_COND_WAIT
+        // reportable
+        if (pithy_print.can_print()) {
+            kbps->sample();
+            srs_trace("-> "SRS_CONSTS_LOG_PLAY
+                " time=%"PRId64", msgs=%d, okbps=%d,%d,%d, ikbps=%d,%d,%d, mw=%d",
+                pithy_print.age(), count,
+                kbps->get_send_kbps(), kbps->get_send_kbps_30s(), kbps->get_send_kbps_5m(),
+                kbps->get_recv_kbps(), kbps->get_recv_kbps_30s(), kbps->get_recv_kbps_5m(),
+                mw_sleep
+            );
+        }
+        
         // we use wait timeout to get messages,
         // for min latency event no message incoming,
         // so the count maybe zero.
-        srs_info("mw wait %dms and got %d msgs %d(%"PRId64"-%"PRId64")ms", 
+        if (count > 0) {
+            srs_verbose("mw wait %dms and got %d msgs %d(%"PRId64"-%"PRId64")ms", 
                 mw_sleep, count, 
                 (count > 0? msgs.msgs[count - 1]->timestamp - msgs.msgs[0]->timestamp : 0),
                 (count > 0? msgs.msgs[0]->timestamp : 0), 
                 (count > 0? msgs.msgs[count - 1]->timestamp : 0));
-#else
+        }
+        
         if (count <= 0) {
+#ifndef SRS_PERF_QUEUE_COND_WAIT
             srs_info("mw sleep %dms for no msg", mw_sleep);
             st_usleep(mw_sleep * 1000);
-        }
+#else
+            srs_verbose("mw wait %dms and got nothing.", mw_sleep);
 #endif
-        srs_info("got %d msgs, min=%d, mw=%d", count, SRS_PERF_MW_MIN_MSGS, mw_sleep);
-
-        // reportable
-        if (pithy_print.can_print()) {
-            kbps->sample();
-            srs_trace("-> "SRS_CONSTS_LOG_PLAY
-                " time=%"PRId64", msgs=%d, okbps=%d,%d,%d, ikbps=%d,%d,%d, mw=%d",
-                pithy_print.age(), count,
-                kbps->get_send_kbps(), kbps->get_send_kbps_30s(), kbps->get_send_kbps_5m(),
-                kbps->get_recv_kbps(), kbps->get_recv_kbps_30s(), kbps->get_recv_kbps_5m(),
-                mw_sleep
-            );
+            // ignore when nothing got.
+            continue;
         }
+        srs_info("got %d msgs, min=%d, mw=%d", count, SRS_PERF_MW_MIN_MSGS, mw_sleep);
         
         // only when user specifies the duration, 
         // we start to collect the durations for each message.

@@ -31,7 +31,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 // current release version
 #define VERSION_MAJOR       2
 #define VERSION_MINOR       0
-#define VERSION_REVISION    70
+#define VERSION_REVISION    71
 // server info.
 #define RTMP_SIG_SRS_KEY "SRS"
 #define RTMP_SIG_SRS_ROLE "origin/edge server"