MT#55447 take a=fmtp into account for transcode=

When adding codecs to the SDP for potential transcoding, use more
sophisticated logic to determine whether the desired codec is already
present. Previously only the raw RTP payload string was used, which
doesn't take codec-specific format options into account. The new
matching function will now also match against existing codecs with
slightly different but compatible a=fmtp options, but will not match
against those with incompatible options.

Change-Id: I7fd298669a4fd69e62edc4760ffd92eff074707b

daemon/codec.c

@@ -4749,11 +4749,17 @@ void codec_store_transcode(struct codec_store *cs, GQueue *offer, struct codec_s
 	// special case of codec_store_offer(): synthesise codecs that were not already present
 	for (GList *l = offer->head; l; l = l->next) {
 		str *codec = l->data;
-		GQueue *pts = g_hash_table_lookup(cs->codec_names, codec);
-		if (pts && pts->length) {
+		// parse out given codec string
+		AUTO_CLEANUP(struct rtp_payload_type *pt, payload_type_destroy)
+			= codec_make_payload_type_sup(codec, cs->media);
+
+		// find matching existing PT if one exists
+		struct rtp_payload_type *pt_match = NULL;
+		codec_store_find_matching_codecs(NULL, &pt_match, cs, codec, pt);
+		if (pt_match) {
 			ilogs(codec, LOG_DEBUG, "Codec " STR_FORMAT
 					" already present (%i)",
-					STR_FMT(codec), GPOINTER_TO_INT(pts->head->data));
+					STR_FMT(codec), pt_match->payload_type);
 			continue;
 		}
 		GQueue *orig_list = g_hash_table_lookup(orig->codec_names, codec);
@@ -4762,7 +4768,7 @@ void codec_store_transcode(struct codec_store *cs, GQueue *offer, struct codec_s
 					" for transcoding",
 					STR_FMT(codec));
 			// create new payload type
-			struct rtp_payload_type *pt = codec_add_payload_type(codec, cs->media, NULL, orig);
+			pt = codec_add_payload_type_pt(pt, cs->media, NULL, orig);
 			if (!pt)
 				continue;
 			pt->for_transcoding = 1;
@@ -4772,6 +4778,7 @@ void codec_store_transcode(struct codec_store *cs, GQueue *offer, struct codec_s
 					STR_FMT(&pt->encoding_with_params), pt->payload_type);
 			codec_touched(cs, pt);
 			codec_store_add_raw_order(cs, pt);
+			pt = NULL;
 			continue;
 		}
 		// XXX duplicate code