neels has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-msc/+/30109 )
Change subject: add some comments to sdp_msg.c,h ......................................................................
add some comments to sdp_msg.c,h
Related: SYS#5066 Change-Id: I68aa4af5d84eaaa08a567377687b6292cce0ce94 --- M include/osmocom/msc/sdp_msg.h M src/libmsc/sdp_msg.c 2 files changed, 14 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-msc refs/changes/09/30109/1
diff --git a/include/osmocom/msc/sdp_msg.h b/include/osmocom/msc/sdp_msg.h index 98d1892..cf1e560 100644 --- a/include/osmocom/msc/sdp_msg.h +++ b/include/osmocom/msc/sdp_msg.h @@ -10,6 +10,7 @@ int sdp_subtype_name_to_payload_type(const char *subtype_name);
struct sdp_audio_codec { + /* Payload type number, like 3 for GSM-FR. */ unsigned int payload_type; /* Like "GSM", "AMR", "EFR", ... */ char subtype_name[16]; diff --git a/src/libmsc/sdp_msg.c b/src/libmsc/sdp_msg.c index 040d32d..0aa5763 100644 --- a/src/libmsc/sdp_msg.c +++ b/src/libmsc/sdp_msg.c @@ -163,6 +163,13 @@ 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) { @@ -294,6 +301,7 @@ #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) @@ -315,6 +323,7 @@ }
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) @@ -336,6 +345,7 @@ }
else if (osmo_str_startswith(src, A_PTIME)) { + /* "a=ptime:20" */ if (sscanf(src, A_PTIME "%u", &sdp->ptime) != 1) return -EINVAL;
@@ -346,14 +356,17 @@ }
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? */ }