5.0.3-dev and add some diagnostics around a pesky fault condition.

Author: mikebrady

configure.ac

@@ -1,7 +1,7 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.50])
-AC_INIT([shairport-sync], [5.0.1+], [4265913+mikebrady@users.noreply.github.com])
+AC_INIT([shairport-sync], [5.0.3-dev], [4265913+mikebrady@users.noreply.github.com])
 : ${CFLAGS="-O3"}
 : ${CXXFLAGS="-O3"}
 AM_INIT_AUTOMAKE([subdir-objects])

rtp.c

@@ -1513,9 +1513,12 @@ int frame_to_ptp_local_time(uint32_t timestamp, uint64_t *time, rtsp_conn_info *
     int32_t frame_difference = timestamp - anchor_rtptime;
     int64_t time_difference = frame_difference;
     time_difference = time_difference * 1000000000;
-    if (conn->input_rate == 0)
-      die("conn->input_rate is zero!");
-    time_difference = time_difference / conn->input_rate;
+    if (conn->input_rate == 0) {
+      debug(1,"in a call to frame_to_ptp_local_time, conn->input_rate is zero!");
+      time_difference = 0;
+    } else {
+      time_difference = time_difference / conn->input_rate;
+    }
     uint64_t ltime = anchor_local_time + time_difference;
     *time = ltime;
     result = 0;