TT#92250 allow codec-strip/offer/except also in answer messages

Change-Id: I9a8dcb3ec83b7037ffa0017a810de506bfa5a356

README.md

@@ -1076,7 +1076,6 @@ Optionally included keys are:
 * `codec`
 
 	Contains a dictionary controlling various aspects of codecs (or RTP payload types).
-	These options are only processed in `offer` messages and ignored otherwise.
 
 	These options can also be put into the `flags` list using a prefix of `codec-`. For example,
 	to set the codec options for two variants of Opus when they're implicitly accepted, (see
@@ -1170,6 +1169,8 @@ Optionally included keys are:
 		be inserted into the offer. (This special exception does not apply to `mask=full`
 		or `strip=full`.)
 
+		This option is only processed in `offer` messages and ignored otherwise.
+
 	* `mask`
 
 		Similar to `strip` except that codecs listed here will still be accepted and
@@ -1185,6 +1186,8 @@ Optionally included keys are:
 		As with the `strip` option, the special keywords `all`  and `full` can be used
 		to mask all codecs that have been offered.
 
+		This option is only processed in `offer` messages and ignored otherwise.
+
 	* `set`
 
 		Contains a list of strings. This list makes it possible to set codec options
@@ -1202,6 +1205,8 @@ Optionally included keys are:
 		different parameters. For example, to specify different bitrates for Opus for both
 		mono and stereo output, one could use `set=[opus/48000/1/16000,opus/48000/2/32000]`.
 
+		This option is only processed in `offer` messages and ignored otherwise.
+
 * `ptime`
 
 	Contains an integer. If set, changes the `a=ptime` attribute's value in the outgoing

daemon/call_interfaces.c

@@ -830,17 +830,17 @@ static void call_ng_flags_flags(struct sdp_ng_flags *out, str *s, void *dummy) {
 				return;
 			if (call_ng_flags_prefix(out, s, "OSRTP-", ng_osrtp_option, NULL))
 				return;
-			if (out->opmode == OP_OFFER) {
-				if (call_ng_flags_prefix(out, s, "codec-strip-", call_ng_flags_str_ht,
-							&out->codec_strip))
-					return;
-				if (call_ng_flags_prefix(out, s, "codec-offer-", call_ng_flags_codec_list,
-							&out->codec_offer))
-					return;
-				if (call_ng_flags_prefix(out, s, "codec-except-", call_ng_flags_str_ht,
-							&out->codec_except))
-					return;
+			if (call_ng_flags_prefix(out, s, "codec-strip-", call_ng_flags_str_ht,
+						&out->codec_strip))
+				return;
+			if (call_ng_flags_prefix(out, s, "codec-offer-", call_ng_flags_codec_list,
+						&out->codec_offer))
+				return;
+			if (call_ng_flags_prefix(out, s, "codec-except-", call_ng_flags_str_ht,
+						&out->codec_except))
+				return;
 #ifdef WITH_TRANSCODING
+			if (out->opmode == OP_OFFER) {
 				if (call_ng_flags_prefix(out, s, "transcode-", call_ng_flags_codec_list,
 							&out->codec_transcode))
 					return;
@@ -1003,14 +1003,16 @@ static void call_ng_process_flags(struct sdp_ng_flags *out, bencode_item_t *inpu
 					STR_FMT(&s));
 	}
 
-	if (opmode == OP_OFFER && (dict = bencode_dictionary_get_expect(input, "codec", BENCODE_DICTIONARY))) {
+	if ((dict = bencode_dictionary_get_expect(input, "codec", BENCODE_DICTIONARY))) {
 		call_ng_flags_list(out, dict, "strip", call_ng_flags_str_ht, &out->codec_strip);
 		call_ng_flags_list(out, dict, "offer", call_ng_flags_codec_list, &out->codec_offer);
 		call_ng_flags_list(out, dict, "except", call_ng_flags_str_ht, &out->codec_except);
 #ifdef WITH_TRANSCODING
-		call_ng_flags_list(out, dict, "transcode", call_ng_flags_codec_list, &out->codec_transcode);
-		call_ng_flags_list(out, dict, "mask", call_ng_flags_str_ht, &out->codec_mask);
-		call_ng_flags_list(out, dict, "set", call_ng_flags_str_ht_split, &out->codec_set);
+		if (opmode == OP_OFFER) {
+			call_ng_flags_list(out, dict, "transcode", call_ng_flags_codec_list, &out->codec_transcode);
+			call_ng_flags_list(out, dict, "mask", call_ng_flags_str_ht, &out->codec_mask);
+			call_ng_flags_list(out, dict, "set", call_ng_flags_str_ht_split, &out->codec_set);
+		}
 #endif
 	}
 }