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add some comments to sdp_msg.c 

Related: SYS#5066
Change-Id: I68aa4af5d84eaaa08a567377687b6292cce0ce94
This commit is contained in:
Neels Hofmeyr 2022-07-19 12:15:27 +02:00
parent 6a8b590ded
commit 6e29b91ae2
1 changed files with 13 additions and 0 deletions
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13
src/libmsc/sdp_msg.c
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@ -163,6 +163,13 @@ struct sdp_audio_codec *sdp_audio_codecs_add_copy(struct sdp_audio_codecs *ac, c
codec->fmtp[0] ? codec->fmtp : NULL);
}
/* Find or create an entry for the given payload_type number in the given list of codecs.
* If the given payload_type number is already present in ac, return the first matching entry.
* If no such payload_type number is present: a) return NULL if create == false;
* b) If create == true, add a mostly empty codec entry to the end of ac with the given payload_type number, and return
* the created entry.
* If create == true, a NULL return value means that there was no unused entry left in ac to add this payload_type.
*/
struct sdp_audio_codec *sdp_audio_codecs_by_payload_type(struct sdp_audio_codecs *ac, unsigned int payload_type,
bool create)
{
@ -285,6 +292,7 @@ int sdp_parse_attrib(struct sdp_msg *sdp, const char *src)
#define A_RECVONLY "recvonly"
if (osmo_str_startswith(src, A_RTPMAP)) {
/* "a=rtpmap:3 GSM/8000" */
char *audio_name;
unsigned int channels = 1;
if (sscanf(src, A_RTPMAP "%u", &payload_type) != 1)
@ -306,6 +314,7 @@ int sdp_parse_attrib(struct sdp_msg *sdp, const char *src)
}
else if (osmo_str_startswith(src, A_FMTP)) {
/* "a=fmtp:112 octet-align=1;mode-set=0,1,2,3" */
char *fmtp_str;
const char *line_end = sdp_msg_line_end(src);
if (sscanf(src, A_FMTP "%u", &payload_type) != 1)
@ -327,6 +336,7 @@ int sdp_parse_attrib(struct sdp_msg *sdp, const char *src)
}
else if (osmo_str_startswith(src, A_PTIME)) {
/* "a=ptime:20" */
if (sscanf(src, A_PTIME "%u", &sdp->ptime) != 1)
return -EINVAL;
@ -337,14 +347,17 @@ int sdp_parse_attrib(struct sdp_msg *sdp, const char *src)
}
else if (osmo_str_startswith(src, A_SENDRECV)) {
/* "a=sendrecv" */
/* TODO? */
}
else if (osmo_str_startswith(src, A_SENDONLY)) {
/* "a=sendonly" */
/* TODO? */
}
else if (osmo_str_startswith(src, A_RECVONLY)) {
/* "a=recvonly" */
/* TODO? */
}