chan_sip+native_bridge_rtp: no directmedia for ptime other than default ptime.

During capabilities selection (joint capabilities of us and peer,
configured capability for this peer, or general configured
capabilities), if sip_new() does not keep framing information,
then directmedia activation will fail for any framing different
from default framing.

ASTERISK-28637

Change-Id: I99257502788653c2816fc991cac7946453082466

bridges/bridge_native_rtp.c

@@ -713,6 +713,8 @@ static int native_rtp_bridge_compatible_check(struct ast_bridge *bridge, struct
 				framing_inst0, framing_inst1);
 			return 0;
 		}
+		ast_debug(3, "Symmetric ptimes on the two call legs (%u). May be able to native bridge in RTP\n",
+			framing_inst0);
 	}
 
 	read_ptime0 = ast_format_cap_get_format_framing(cap0, ast_channel_rawreadformat(bc0->chan));
@@ -726,6 +728,9 @@ static int native_rtp_bridge_compatible_check(struct ast_bridge *bridge, struct
 			read_ptime0, write_ptime1, read_ptime1, write_ptime0);
 		return 0;
 	}
+	ast_debug(3, "Bridge '%s': Packetization comparison success between RTP streams (read_ptime0:%d == write_ptime1:%d and read_ptime1:%d == write_ptime0:%d).\n",
+		bridge->uniqueid,
+		read_ptime0, write_ptime1, read_ptime1, write_ptime0);
 
 	return 1;
 }

channels/chan_sip.c

@@ -8193,8 +8193,11 @@ static struct ast_channel *sip_new(struct sip_pvt *i, int state, const char *tit
 	/* Use only the preferred audio format, which is stored at the '0' index */
 	fmt = ast_format_cap_get_best_by_type(what, AST_MEDIA_TYPE_AUDIO); /* get the best audio format */
 	if (fmt) {
+		int framing;
+
 		ast_format_cap_remove_by_type(caps, AST_MEDIA_TYPE_AUDIO); /* remove only the other audio formats */
-		ast_format_cap_append(caps, fmt, 0); /* add our best choice back */
+		framing = ast_format_cap_get_format_framing(what, fmt);
+		ast_format_cap_append(caps, fmt, framing); /* add our best choice back */
 	} else {
 		/* If we don't have an audio format, try to get something */
 		fmt = ast_format_cap_get_format(caps, 0);