ZLKMedia/3rdpart/media-server/librtsp/include/sdp.h

#ifndef _rfc4566_sdp_h_
#define _rfc4566_sdp_h_

#ifdef __cplusplus
extern "C" {
#endif

typedef struct sdp_t sdp_t;

enum { SDP_V_VERSION_0 = 0 };
enum { SDP_C_NETWORK_UNKNOWN=0, SDP_C_NETWORK_IN };
enum { SDP_C_ADDRESS_UNKNOWN=0, SDP_C_ADDRESS_IP4, SDP_C_ADDRESS_IP6 };
enum { SDP_A_INACTIVE = 0, SDP_A_SENDONLY = 0x01, SDP_A_RECVONLY = 0x02, SDP_A_SENDRECV = 0x03 /*default*/, };
enum { SDP_M_MEDIA_UNKOWN = 0, SDP_M_MEDIA_AUDIO, SDP_M_MEDIA_VIDEO, SDP_M_MEDIA_TEXT, SDP_M_MEDIA_APPLICATION, SDP_M_MEDIA_MESSAGE };

sdp_t* sdp_parse(const char* s, int len);
void sdp_destroy(sdp_t* sdp);

int sdp_version_get(sdp_t* sdp);

/// 5.2. Origin ("o=")
/// @param[out] username username
/// @param[out] session session id
/// @param[out] version session version
/// @param[out] network network type, IN-internet
/// @param[out] addrtype address type, IP4-IP v4, IP6-IP v6
/// @param[out] address connection address, multicast/unicast address
/// @return 0-ok, -1 if don't have connection
int sdp_origin_get(sdp_t* sdp, const char **username, const char** session, const char** version, const char** network, const char** addrtype, const char** address);
int sdp_origin_get_network(sdp_t* sdp); // SDP_C_NETWORK_IN
int sdp_origin_get_addrtype(sdp_t* sdp); // SDP_C_ADDRESS_IP4/SDP_C_ADDRESS_IP6

/// @return NULL-if don't have keyword
const char* sdp_session_get_name(sdp_t* sdp);
const char* sdp_session_get_information(sdp_t* sdp);
const char* sdp_uri_get(sdp_t* sdp);

int sdp_email_count(sdp_t* sdp);
int sdp_phone_count(sdp_t* sdp);
const char* sdp_email_get(sdp_t* sdp, int idx);
const char* sdp_phone_get(sdp_t* sdp, int idx);

// c=IN IP4 224.2.36.42/127
// c=IN IP4 224.2.1.1/127/3
// c=IN IP6 FF15::101/3
/// @param[out] network network type, IN-internet
/// @param[out] addrtype address type, IP4-IP v4, IP6-IP v6
/// @param[out] address connection address, multicast/unicast address
/// @return 0-ok, -1 if don't have connection
int sdp_connection_get(sdp_t* sdp, const char** network, const char** addrtype, const char** address);
int sdp_connection_get_address(sdp_t* sdp, char* ip, int bytes); // ipv4/ipv6 address, alloc by caller
int sdp_connection_get_network(sdp_t* sdp); // SDP_C_NETWORK_IN
int sdp_connection_get_addrtype(sdp_t* sdp); // SDP_C_ADDRESS_IP4/SDP_C_ADDRESS_IP6

int sdp_bandwidth_count(sdp_t* sdp);
const char* sdp_bandwidth_get_type(sdp_t* sdp, int idx); // CT/AS
int sdp_bandwidth_get_value(sdp_t* sdp, int idx); // kbps-kilobits per second

// 1. These values are the decimal representation of Network Time Protocol (NTP) time values in seconds
//    since 1900 [13]. To convert these values to UNIX time, subtract decimal 2208988800.
// 2. If the <stop-time> is set to zero, then the session is not bounded, though it will not become active 
//    until after the <start-time>. If the <start-time> is also zero, the session is regarded as permanent.
int sdp_timing_count(sdp_t* sdp);
int sdp_timing_repeat_count(sdp_t* sdp, int time);
int sdp_timing_repeat_offset_count(sdp_t* sdp, int time);
int sdp_timing_timezone_count(sdp_t* sdp, int time);
int sdp_timing_get(sdp_t* sdp, int idx, const char** start, const char** stop);
const char* sdp_repeat_get(sdp_t* sdp, int idx);
const char* sdp_timezone_get(sdp_t* sdp, int idx);

/// @return NULL-if don't have keyword
const char* sdp_encryption_get(sdp_t* sdp);

int sdp_media_count(sdp_t* sdp);
const char* sdp_media_type(sdp_t* sdp, int media);
int sdp_media_port(sdp_t* sdp, int media, int port[], int num); // return port count
const char* sdp_media_proto(sdp_t* sdp, int media);
int sdp_media_formats(sdp_t* sdp, int media, int *formats, int count); // return format count

/*
RFC4566 4.1.  Media and Transport Information
 In addition to media format and transport protocol, SDP conveys
address and port details.  For an IP multicast session, these
comprise:
    The multicast group address for media
    The transport port for media
This address and port are the destination address and destination
port of the multicast stream, whether being sent, received, or both.

For unicast IP sessions, the following are conveyed:
    The remote address for media
    The remote transport port for media

The semantics of this address and port depend on the media and
transport protocol defined.  By default, this SHOULD be the remote
address and remote port to which data is sent.
 
RFC 4570 SDP Source Filters
 c=IN IP4 224.2.1.1/127/3
 a=source-filter: incl IN IP4 224.2.1.1 192.0.2.10
 a=source-filter: incl IN IP4 224.2.1.3 192.0.2.42
 */
int sdp_media_get_connection(sdp_t* sdp, int media, const char** network, const char** addrtype, const char** address);
int sdp_media_get_connection_address(sdp_t* sdp, int media, char* ip, int bytes);
int sdp_media_get_connection_network(sdp_t* sdp, int media);
int sdp_media_get_connection_addrtype(sdp_t* sdp, int media);
const char* sdp_media_attribute_find(sdp_t* sdp, int media, const char* name);
int sdp_media_attribute_list(sdp_t* sdp, int media, const char* name, void (*onattr)(void* param, const char* name, const char* value), void* param);

const char* sdp_media_get_information(sdp_t* sdp, int media);

int sdp_media_bandwidth_count(sdp_t* sdp, int media);
const char* sdp_media_bandwidth_get_type(sdp_t* sdp, int media, int idx); // CT/AS
int sdp_media_bandwidth_get_value(sdp_t* sdp, int media, int idx); // kbps-kilobits per second

int sdp_attribute_count(sdp_t* sdp);
/// param[in] name attrbution name, NULL-for list all attributions
int sdp_attribute_list(sdp_t* sdp, const char* name, void (*onattr)(void* param, const char* name, const char* value), void* param);
int sdp_attribute_get(sdp_t* sdp, int idx, const char** name, const char** value);
const char* sdp_attribute_find(sdp_t* sdp, const char* name);

/// "sendrecv" SHOULD be assumed as the default for sessions that 
/// are not of the conference type "broadcast" or "H332" (see below).
/// return -1-not found, SDP_A_SENDRECV/SDP_A_SENDONLY/SDP_A_XXX
int sdp_media_mode(struct sdp_t* sdp, int media);

#ifdef __cplusplus
}
#endif
#endif /* !_sdp_h_ */