add sdp_audio_codec_is_set

Change-Id: I078efe5b42367ad1089c53f11f7eb6f3a9dd9443

include/osmocom/msc/sdp_msg.h

@@ -36,6 +36,7 @@ struct sdp_msg {
 
 const char *sdp_msg_line_end(const char *src);
 
+bool sdp_audio_codec_is_set(const struct sdp_audio_codec *a);
 int sdp_audio_codec_cmp(const struct sdp_audio_codec *a, const struct sdp_audio_codec *b,
 			bool cmp_fmtp, bool cmp_payload_type);
 int sdp_audio_codecs_cmp(const struct sdp_audio_codecs *a, const struct sdp_audio_codecs *b,

src/libmsc/sdp_msg.c

@@ -30,6 +30,11 @@
 #include <osmocom/msc/debug.h>
 #include <osmocom/msc/sdp_msg.h>
 
+bool sdp_audio_codec_is_set(const struct sdp_audio_codec *a)
+{
+	return a && a->subtype_name[0];
+}
+
 /* Compare name, rate and fmtp, returning typical cmp result: 0 on match, and -1 / 1 on mismatch.
  * If cmp_fmtp is false, do *not* compare the fmtp string; if true, compare fmtp 1:1 as strings.
  * If cmp_payload_type is false, do *not* compare the payload_type number.