TT#54800 fix ptime overrides

Adds a new option ptime-reverse to complement setting of ptime towards
the offerer. This and ptime setting are now ignored in answers.

Change-Id: Icbc04f191cbc194b75b72a97832fcaba58feb10e
(cherry picked from commit e6b1b1e3c3)

README.md

@@ -1596,6 +1596,18 @@ Optionally included keys are:
 	been requested for transcoding. Note that not all codecs support all packetization
 	intervals.
 
+	The selected ptime (which represents the duration of a single media packet in milliseconds)
+	will be used towards the endpoint receiving this offer, even if the matching answer
+	prefers a different ptime.
+
+	This option is ignored in `answer` messages. See below for the reverse.
+
+* `ptime-reverse`
+
+	This is the reciprocal to `ptime`. It sets the ptime to be used towards the endpoint
+	who has sent the offer. It will be inserted in the `answer` SDP. This option is also
+	ignored in `answer` messages.
+
 * `supports`
 
 	Contains a list of strings. Each string indicates support for an additional feature

daemon/call.c

@@ -1927,11 +1927,21 @@ int monologue_offer_answer(struct call_monologue *other_ml, GQueue *streams,
 
 		// codec and RTP payload types handling
 		if (sp->ptime > 0) {
-			media->ptime = sp->ptime;
-			other_media->ptime = sp->ptime;
+			if (!MEDIA_ISSET(media, PTIME_OVERRIDE))
+				media->ptime = sp->ptime;
+			if (!MEDIA_ISSET(other_media, PTIME_OVERRIDE))
+				other_media->ptime = sp->ptime;
 		}
-		if (flags && flags->ptime > 0)
+		if (flags && flags->ptime > 0) {
 			media->ptime = flags->ptime;
+			MEDIA_SET(media, PTIME_OVERRIDE);
+			MEDIA_SET(other_media, PTIME_OVERRIDE);
+		}
+		if (flags && flags->rev_ptime > 0) {
+			other_media->ptime = flags->rev_ptime;
+			MEDIA_SET(media, PTIME_OVERRIDE);
+			MEDIA_SET(other_media, PTIME_OVERRIDE);
+		}
 		codec_rtp_payload_types(media, other_media, &sp->rtp_payload_types, flags);
 		codec_handlers_update(media, other_media, flags);
 

daemon/call_interfaces.c

@@ -804,7 +804,13 @@ static void call_ng_process_flags(struct sdp_ng_flags *out, bencode_item_t *inpu
 	out->tos = bencode_dictionary_get_int_str(input, "TOS", 256);
 	bencode_get_alt(input, "record-call", "record call", &out->record_call_str);
 	bencode_dictionary_get_str(input, "metadata", &out->metadata);
-	out->ptime = bencode_dictionary_get_int_str(input, "ptime", 0);
+
+	if (opmode == OP_OFFER) {
+		out->ptime = bencode_dictionary_get_int_str(input, "ptime", 0);
+		out->rev_ptime = bencode_dictionary_get_int_str(input, "ptime-reverse", 0);
+		if (out->rev_ptime == 0)
+			out->rev_ptime = bencode_dictionary_get_int_str(input, "ptime reverse", 0);
+	}
 
 	if (bencode_dictionary_get_str(input, "xmlrpc-callback", &s)) {
 		if (sockaddr_parse_any_str(&out->xmlrpc_callback, &s))

daemon/codec.c

@@ -1134,6 +1134,9 @@ void __rtp_payload_type_add_recv(struct call_media *media,
 {
 	if (!pt)
 		return;
+	// update ptime in case it was overridden
+	if (media->ptime > 0)
+		pt->ptime = media->ptime;
 	g_hash_table_insert(media->codecs_recv, &pt->payload_type, pt);
 	__rtp_payload_type_add_name(media->codec_names_recv, pt);
 	g_queue_push_tail(&media->codecs_prefs_recv, pt);
@@ -1144,6 +1147,9 @@ void __rtp_payload_type_add_send(struct call_media *other_media,
 {
 	if (!pt)
 		return;
+	// update ptime in case it was overridden
+	if (other_media->ptime > 0)
+		pt->ptime = other_media->ptime;
 	g_hash_table_insert(other_media->codecs_send, &pt->payload_type, pt);
 	__rtp_payload_type_add_name(other_media->codec_names_send, pt);
 	g_queue_push_tail(&other_media->codecs_prefs_send, pt);
@@ -1159,8 +1165,8 @@ void __rtp_payload_type_add_send_dup(struct call_media *other_media,
 static void __rtp_payload_type_add(struct call_media *media, struct call_media *other_media,
 		struct rtp_payload_type *pt)
 {
-	__rtp_payload_type_add_recv(media, pt);
 	__rtp_payload_type_add_send_dup(other_media, pt);
+	__rtp_payload_type_add_recv(media, pt);
 }
 
 static void __payload_queue_free(void *qq) {
@@ -1310,6 +1316,7 @@ void codec_rtp_payload_types(struct call_media *media, struct call_media *other_
 				STR_FMT(&pt->encoding_with_params), pt->payload_type);
 		__rtp_payload_type_add_recv(media, pt);
 	}
+
 #endif
 
 	g_hash_table_destroy(removed);

include/call.h

@@ -165,6 +165,7 @@ enum call_type {
 #define MEDIA_FLAG_ICE_CONTROLLING		0x00200000
 #define MEDIA_FLAG_LOOP_CHECK			0x00400000
 #define MEDIA_FLAG_TRANSCODE			0x00800000
+#define MEDIA_FLAG_PTIME_OVERRIDE		0x01000000
 
 /* access macros */
 #define SP_ISSET(p, f)		bf_isset(&(p)->sp_flags, SP_FLAG_ ## f)

include/call_interfaces.h

@@ -37,7 +37,8 @@ struct sdp_ng_flags {
 	GQueue codec_transcode;
 	GHashTable *codec_mask;
 	GHashTable *codec_set;
-	int ptime;
+	int ptime,
+	    rev_ptime;
 	GHashTable *sdes_no;
 	int asymmetric:1,
 	    no_redis_update:1,