Changeset 5752 for pjproject/trunk/pjmedia/src/pjmedia/rtp.c

Timestamp:

Mar 8, 2018 2:01:26 AM (6 years ago)

Author:

ming

Message:

Fixed #865: More clever RTP transport remote address switch

The summary of changes:

• To solve no 2:

Add callback rtp_cb2(pjmedia_tp_cb_param *param) which allows application to get more info from the media transport, such as the packet's source address.

• To solve no 3:

Add compile time option PJMEDIA_TRANSPORT_SWITCH_REMOTE_ADDR (by default enabled). Currently, there are already runtime options PJMEDIA_UDP_NO_SRC_ADDR_CHECKING and PJMEDIA_ICE_NO_SRC_ADDR_CHECKING, but there are a few drawbacks:

• the options are not exported to the higher level, such as stream, or pjsua.
• the options are separate for each transport, UDP and ICE, there's no single option to do this.

• To solve no 1:

Using the new rtp_cb2() callback, move the functionality to check the packet's source address to the stream/video stream.
By checking the RTP pt and SSRC, there are a few advantages:

• When receiving packets from multiple sources, stream can choose the packet with the correct SSRC as advertised from the SDP, and discard the others (see also ticket #1366).
• If remote address switch is enabled, a faster switch can be achieved as soon as packet with correct ssrc is received, instead of waiting for several consecutive packets (according to setting PJMEDIA_RTP_NAT_PROBATION_CNT).

File:

• pjproject/trunk/pjmedia/src/pjmedia/rtp.c (modified) (1 diff)

pjproject/trunk/pjmedia/src/pjmedia/rtp.c

@@ -247 +247 @@
     if (pj_ntohl(hdr->ssrc) != ses->peer_ssrc) {
         seq_st.status.flag.badssrc = 1;
-        ses->peer_ssrc = pj_ntohl(hdr->ssrc);
+        if (!ses->has_peer_ssrc)
+            ses->peer_ssrc = pj_ntohl(hdr->ssrc);
     }