sdp.h

sip协议栈

  sdp_bandwidth_t  *m_bandwidths;	/**< Bandwidth specification */
  sdp_key_t        *m_key;		/**< Media key */
  sdp_attribute_t  *m_attributes;	/**< Media attributes */

  void             *m_user;	        /**< User data. */

  /** Rejected media */
  unsigned          m_rejected : 1;     
  /** Inactive, recvonly, sendonly, sendrecv */
  /* sdp_mode_t */ unsigned m_mode : 2;
  unsigned          : 0;
};

/** Text list */
struct sdp_list_s
{
  int              l_size;		/**< sizeof sdp_list_t  */
  sdp_list_t      *l_next;		/**< Next text entry in list */
  sdp_text_t      *l_text;	        /**< Text as C string */
};

/** Mapping from RTP payload to codec.
 * 
 * The sdp_rtpmap_t() structure defines a mapping from an RTP payload to a
 * particular codec.  In case of well-known payloads, the sdp_rtpmap_t()
 * structure may be predefined, that is, generated by SDP parser without
 * corresponding "a" line in the SDP.  The sdp_rtpmap_t() structure may also
 * contain the @c fmtp attribute, which is used to convey format-specific
 * parameters.
 */
struct sdp_rtpmap_s {
  int            rm_size;		/**< sizeof sdp_rtpmap_t  */
  sdp_rtpmap_t  *rm_next;		/**< Next RTP map entry  */
  sdp_text_t    *rm_encoding;		/**< Codec name */
  unsigned long  rm_rate;		/**< Sampling rate */
  sdp_text_t    *rm_params;		/**< Format-specific parameters  */
  sdp_text_t    *rm_fmtp;	        /**< Contents of fmtp */
  unsigned       rm_predef : 1;	        /**< is this entry well-known? */
  unsigned       rm_pt : 7;		/**< Payload type */
  unsigned       rm_any : 1;	        /**< Wildcard entry */
  int       :0;
};

SOFIAPUBVAR sdp_rtpmap_t const * const sdp_rtpmap_well_known[128];

/** Duplicate an SDP session description structure. */
SOFIAPUBFUN sdp_session_t *sdp_session_dup(su_home_t *, sdp_session_t const *);

/** Duplicate an SDP origin structure. */
SOFIAPUBFUN
sdp_origin_t    *sdp_origin_dup(su_home_t *, sdp_origin_t const *);

/** Duplicate an SDP connection structure. */
SOFIAPUBFUN
sdp_connection_t *sdp_connection_dup(su_home_t *home, sdp_connection_t const *);

/** Duplicate an SDP bandwidth structure. */
SOFIAPUBFUN
sdp_bandwidth_t  *sdp_bandwidth_dup(su_home_t *home, sdp_bandwidth_t const *);

/** Duplicate an SDP time structure. */
SOFIAPUBFUN
sdp_time_t       *sdp_time_dup(su_home_t *home, sdp_time_t const *);

/** Duplicate an SDP repeat structure. */
SOFIAPUBFUN
sdp_repeat_t     *sdp_repeat_dup(su_home_t *home, sdp_repeat_t const *);

/** Duplicate an SDP timezone structure. */
SOFIAPUBFUN
sdp_zone_t       *sdp_zone_dup(su_home_t *home, sdp_zone_t const *);

/** Duplicate an SDP key structure. */
SOFIAPUBFUN
sdp_key_t        *sdp_key_dup(su_home_t *home, sdp_key_t const *);

/** Duplicate an SDP attribute structure. */
SOFIAPUBFUN
sdp_attribute_t  *sdp_attribute_dup(su_home_t *home, sdp_attribute_t const *);

/** Duplicate an SDP media description structure. */
SOFIAPUBFUN
sdp_media_t *sdp_media_dup(su_home_t *, sdp_media_t const *,
			   sdp_session_t *);

/** Duplicate a list of SDP media description structures. */
SOFIAPUBFUN
sdp_media_t *sdp_media_dup_all(su_home_t *, sdp_media_t const *,
			       sdp_session_t *);

/** Duplicate a list structure. */
SOFIAPUBFUN
sdp_list_t       *sdp_list_dup(su_home_t *home, sdp_list_t const *);

/** Duplicate an rtpmap structure. */
SOFIAPUBFUN
sdp_rtpmap_t     *sdp_rtpmap_dup(su_home_t *home, sdp_rtpmap_t const *);

/** Compare two session descriptions. */
SOFIAPUBFUN int sdp_session_cmp(sdp_session_t const *a,
				sdp_session_t const *b);

/** Compare two origin fields */
SOFIAPUBFUN int sdp_origin_cmp(sdp_origin_t const *a,
			       sdp_origin_t const *b);

/** Compare two connection fields */
SOFIAPUBFUN int sdp_connection_cmp(sdp_connection_t const *,
				   sdp_connection_t const *b);

/** Compare two bandwidth (b=) fields */
SOFIAPUBFUN int sdp_bandwidth_cmp(sdp_bandwidth_t const *a,
				  sdp_bandwidth_t const *b);

/** Compare two time fields */
SOFIAPUBFUN int sdp_time_cmp(sdp_time_t const *a, sdp_time_t const *b);

/* Compare two repeat (r=) fields */
SOFIAPUBFUN int sdp_repeat_cmp(sdp_repeat_t const *a, sdp_repeat_t const *b);

/* Compare two zone (z=) fields */
SOFIAPUBFUN int sdp_zone_cmp(sdp_zone_t const *a, sdp_zone_t const *b);

/** Compare two key (k=) fields. */
SOFIAPUBFUN int sdp_key_cmp(sdp_key_t const *a, sdp_key_t const *b);

/** Compare two attribute (a=) fields */
SOFIAPUBFUN int sdp_attribute_cmp(sdp_attribute_t const *,
				  sdp_attribute_t const *);

/** Compare two media (m=) descriptions */
SOFIAPUBFUN int sdp_media_cmp(sdp_media_t const *, sdp_media_t const *);

/** Compare two rtpmap structures. */
SOFIAPUBFUN int sdp_rtpmap_cmp(sdp_rtpmap_t const *a, sdp_rtpmap_t const *b);

/** Compare two text lists */
SOFIAPUBFUN int sdp_list_cmp(sdp_list_t const *a, sdp_list_t const *b);

/** Get connections of a media description */
SOFIAPUBFUN sdp_connection_t *sdp_media_connections(sdp_media_t const *m);

/** Check if media uses RTP as its transport protocol  */
SOFIAPUBFUN int sdp_media_has_rtp(sdp_media_t const *m);

/** Set media type */
SOFIAPUBFUN void sdp_media_type(sdp_media_t *m, char const *s);

/** Set transport protocol */
SOFIAPUBFUN void sdp_media_transport(sdp_media_t *m, char const *s);

/** Find named attribute from given list. */
SOFIAPUBFUN sdp_attribute_t  *sdp_attribute_find(sdp_attribute_t const *a,
						 char const *name);

/** Find named attribute from given lists. */
SOFIAPUBFUN sdp_attribute_t *sdp_attribute_find2(sdp_attribute_t const *a, 
						 sdp_attribute_t const *a2, 
						 char const *name);

/** Get session mode from attribute list. */
SOFIAPUBFUN sdp_mode_t sdp_attribute_mode(sdp_attribute_t const *a,
					  sdp_mode_t defmode);

/** Get session mode from attribute list. */
SOFIAPUBFUN sdp_attribute_t *sdp_attribute_by_mode(su_home_t *, 
						   sdp_mode_t mode);

/** Find a mapped attribute. */
SOFIAPUBFUN 
sdp_attribute_t *sdp_attribute_mapped_find(sdp_attribute_t const *a, 
					   char const *name, 
					   int pt, char **return_result);

/** Append a attribute to a list of attributes. */
SOFIAPUBFUN void sdp_attribute_append(sdp_attribute_t **list, 
			  sdp_attribute_t const *a);

/** Replace a attribute within a list of attributes. */
SOFIAPUBFUN int sdp_attribute_replace(sdp_attribute_t **list, 
				      sdp_attribute_t *a,
				      sdp_attribute_t **return_replaced);

/** Remove a named attribute from a list of attributes. */
SOFIAPUBFUN sdp_attribute_t *sdp_attribute_remove(sdp_attribute_t **list, 
						  char const *name);

/* Return 1 if m= line struct matches with given type and name */
SOFIAPUBFUN unsigned sdp_media_match(sdp_media_t const *m,
				     sdp_media_e type,
				     sdp_text_t *type_name,
				     sdp_proto_e proto,
				     sdp_text_t *proto_name);

SOFIAPUBFUN unsigned sdp_media_match_with(sdp_media_t const *a,
					  sdp_media_t const *b);

/** Count media lines in SDP. */
SOFIAPUBFUN unsigned sdp_media_count(sdp_session_t const *sdp,
				     sdp_media_e type,
				     sdp_text_t *type_name,
				     sdp_proto_e proto,
				     sdp_text_t *proto_name);

SOFIAPUBFUN unsigned sdp_media_count_with(sdp_session_t const *sdp,
					  sdp_media_t const *m0);

/** Return true if media uses RTP */
SOFIAPUBFUN int sdp_media_uses_rtp(sdp_media_t const *m);

/** Check if payload type, rtp rate and parameters match in rtpmaps*/
SOFIAPUBFUN int sdp_rtpmap_match(sdp_rtpmap_t const *, sdp_rtpmap_t const *);

/** Search for matching rtpmap from list */
SOFIAPUBFUN sdp_rtpmap_t *sdp_rtpmap_find_matching(sdp_rtpmap_t const *list,
						   sdp_rtpmap_t const *rm);

/* ======================================================================== */

/** Flags given to sdp_parse()/sdp_print(). */
enum sdp_parse_flags_e {
  /** Accept only conforming SDP */
  sdp_f_strict = 1,
  /** Accept any network type. */
  sdp_f_anynet = 2,		
  /** Reallocate message. */ 
  sdp_f_realloc = 4,
  /** Include well-known rtpmaps in message, too */
  sdp_f_all_rtpmaps = 8,
  /** Print buffer already contains a valid prefix */
  sdp_f_print_prefix = 16,
  /** Connection line with INADDR_ANY is considered equal to sendonly */
  sdp_f_mode_0000 = 32,
  /** Don't run sanity check */
  sdp_f_insane = 64,
  /** Don't require c= for each media line */
  sdp_f_c_missing = 128,
  /** Parse SDP config files */
  sdp_f_config = 256,
  /** Do not generate or parse SDP mode */
  sdp_f_mode_manual = 512,
  /** Always generate media-level mode attributes */
  sdp_f_mode_always = 1024
};

/** SDP parser handle. */
typedef struct sdp_parser_s sdp_parser_t;
typedef sdp_parser_t  *sdp_parser;

SOFIAPUBFUN sdp_parser_t *sdp_parse(su_home_t *,
				    char const msg[], int msgsize, int flags);
SOFIAPUBFUN char const *sdp_parsing_error(sdp_parser_t *p);
SOFIAPUBFUN sdp_session_t *sdp_session(sdp_parser_t *p);
SOFIAPUBFUN void sdp_parser_free(sdp_parser_t *p);

SOFIAPUBFUN int sdp_sanity_check(sdp_parser_t *);

SOFIAPUBFUN su_home_t *sdp_parser_home(sdp_parser_t *);

/* ======================================================================== */

/** SDP printer handle */
typedef struct sdp_printer_s sdp_printer_t;
typedef sdp_printer_t *sdp_printer;

SOFIAPUBFUN sdp_printer_t *sdp_print(su_home_t *, sdp_session_t const *session, 
				     char msgbuf[], int maxmsgsize, int flags);
SOFIAPUBFUN char const *sdp_printing_error(sdp_printer_t *p);
SOFIAPUBFUN char const *sdp_message(sdp_printer_t *p);
SOFIAPUBFUN int   sdp_message_size(sdp_printer_t *p);
SOFIAPUBFUN void sdp_printer_free(sdp_printer_t *p);

#define sdp_mapped_attribute_find sdp_attribute_mapped_find
#define sdp_free_parser  sdp_parser_free
#define sdp_free_printer sdp_printer_free

SOFIA_END_DECLS

#endif /* SDP_H */