完善获取媒体读取器个数方法

src/Rtsp/RtspMediaSource.h

@@ -65,7 +65,12 @@ public:
 		//获取媒体源的rtp环形缓冲
 		return _pRing;
 	}
-	const string& getSdp() const {
+
+    int readerCount() override {
+        return _pRing->readerCount();
+	}
+
+    const string& getSdp() const {
 		//获取该源的媒体描述信息
 		return _strSdp;
 	}

src/Rtsp/RtspSession.cpp

@@ -716,7 +716,7 @@ bool RtspSession::handleReq_Play(const Parser &parser) {
 			auto iStartTime = 1000 * atof(strStart.data());
 			InfoL << "rtsp seekTo(ms):" << iStartTime;
 			useBuf = !pMediaSrc->seekTo(iStartTime);
-		}else if(pMediaSrc->getRing()->readerCount() == 0){
+		}else if(pMediaSrc->readerCount() == 0){
 			//第一个消费者
 			pMediaSrc->seekTo(0);
 		}

src/Rtsp/RtspToRtmpMediaSource.h

@@ -85,6 +85,9 @@ public:
             _rtmpMuxer->setListener(listener);
         }
     }
+    int readerCount() override {
+        return RtspMediaSource::readerCount() + _rtmpMuxer->readerCount();
+    }
 private:
     RtspDemuxer::Ptr _rtspDemuxer;
     RtmpMediaSourceMuxer::Ptr _rtmpMuxer;