add srs_rtmp_free_packet for srs-librtmp

@@ -1116,6 +1116,11 @@ int srs_rtmp_write_packet(srs_rtmp_t rtmp, char type, u_int32_t timestamp, char*
     return ret;
 }
     
+void srs_rtmp_free_packet(char* data)
+{
+    srs_freepa(data);
+}
+
 srs_bool srs_rtmp_is_onMetaData(char type, char* data, int size)
 {
     int ret = ERROR_SUCCESS;

@@ -285,6 +285,7 @@ extern int srs_rtmp_bandwidth_check(srs_rtmp_t rtmp,
 *             FlvTagAudio, @see "E.4.2.1 AUDIODATA"
 *            FlvTagVideo, @see "E.4.3.1 VIDEODATA"
 *            FlvTagScript, @see "E.4.4.1 SCRIPTDATA"
+*            User can free the packet by srs_rtmp_free_packet.
 * @param size, size of packet.
 * @return the error code. 0 for success; otherwise, error.
 *
@@ -303,6 +304,11 @@ extern int srs_rtmp_write_packet(srs_rtmp_t rtmp,
 );
     
 /**
+ * Free the packet allocated by srs_rtmp_read_packet.
+ */
+extern void srs_rtmp_free_packet(char* data);
+
+/**
 * whether type is script data and the data is onMetaData.
 */
 extern srs_bool srs_rtmp_is_onMetaData(char type, char* data, int size);