possible fix or MODENDP-79 - Duplicate rtp timestamps from portaudio to sip

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@7323 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/switch_rtp.c

@@ -1543,6 +1543,9 @@ static int rtp_common_write(switch_rtp_t *rtp_session,
 			rtp_session->ts = (uint32_t) timestamp;
 		} else if (rtp_session->timer.timer_interface) {
 			rtp_session->ts = rtp_session->timer.samplecount;
+			if (rtp_session->ts <= rtp_session->last_write_ts) {
+				rtp_session->ts = rtp_session->last_write_ts + rtp_session->samples_per_interval;
+			}
 		} else {
 			rtp_session->ts += rtp_session->samples_per_interval;
 		}