优化sdp解析，兼容带有f=的设备

src/main/java/com/genersoft/iot/vmp/gb28181/bean/Gb28181Sdp.java

@@ -0,0 +1,46 @@
+package com.genersoft.iot.vmp.gb28181.bean;
+
+import javax.sdp.SessionDescription;
+
+/**
+ * 28181 的SDP解析器
+ */
+public class Gb28181Sdp  {
+    private SessionDescription baseSdb;
+    private String ssrc;
+
+    private String mediaDescription;
+
+    public static Gb28181Sdp getInstance(SessionDescription baseSdb, String ssrc, String mediaDescription) {
+        Gb28181Sdp gb28181Sdp = new Gb28181Sdp();
+        gb28181Sdp.setBaseSdb(baseSdb);
+        gb28181Sdp.setSsrc(ssrc);
+        gb28181Sdp.setMediaDescription(mediaDescription);
+        return gb28181Sdp;
+    }
+
+
+    public SessionDescription getBaseSdb() {
+        return baseSdb;
+    }
+
+    public void setBaseSdb(SessionDescription baseSdb) {
+        this.baseSdb = baseSdb;
+    }
+
+    public String getSsrc() {
+        return ssrc;
+    }
+
+    public void setSsrc(String ssrc) {
+        this.ssrc = ssrc;
+    }
+
+    public String getMediaDescription() {
+        return mediaDescription;
+    }
+
+    public void setMediaDescription(String mediaDescription) {
+        this.mediaDescription = mediaDescription;
+    }
+}