sdp.docs

this is simple sip stack.

/* -*- c -*- */

/**@mainpage SDP Module

@section sdp_meta Module Meta Information

The @b sdp module provides a simple "C" parser interface for SDP 
[<a href="ftp://ftp.funet.fi/rfc/rfc2327.txt">RFC2327</a>], <em>Session
Description Protocol</em>.

@CONTACT Pekka Pessi <[e-mail]>

@STATUS Core library

@LICENSE LGPL

Contributor(s):
- Pekka Pessi <[e-mail]>
- Jari Selin <[e-mail]>

@section sdp_parser SDP Parser

SDP parser parses an SDP message and converts it to internally used SDP
datatypes.

Typically, the SDP parser is used as follows:

@code
 sdp_parser parser = sdp_parse(home, message, len, 0);

 if (!sdp_session(parser)) {
   show(sdp_parsing_error(parser));
 } else {
   sdp_session_t *sdp = sdp_session(parser);
@endcode
  Act upon session description, then free the parser:
@code
 }
 sdp_parser_free(parser);
@endcode

There are various flags indicating what kind of SDP variants parser accepts. 
The sanity check run after parsing can be disabled by including flag
#sdp_f_insane. The parser can be used to parse syntactically vague
configuration files when using flag #sdp_f_config. The parser will then
accept * for media, protocol and port, for instance.

@todo strict (parser accepts some non-conforming SDP even with strict)

@section sdp_printer SDP Printer

SDP printer converts internally used SDP datatypes to the standard SDP
format.

Typically, the SDP printer is used as follows:
@code
 char buffer[512];
 sdp_printer printer = sdp_print(home, session, buffer, sizeof(buffer), 0);

 if (sdp_message(printer)) {
   char const *msg = sdp_message(printer);
   int  msgsize = sdp_message_size(printer);
@endcode

At this point, application can use the SDP message contents, e.g., it can
send them to network, and then free the message:
@code
 }
 else {
   show_critical_error(sdp_printing_error(printer));
 }
 sdp_printer_free(printer);
@endcode 

@section sdp_example Example

Examples on using SDP parser can be found from @b sdp_test.c and @b
nua.c. Here is an simple example, which decodes an SDP text in @a
original, increments the version number in the origin line, and encodes
the SDP description again to @a buf.

@code
int increment_sdp_version(char buf[], int bsize, 
                          char const *original, int osize)
{
  su_home_t home[1] = { SU_HOME_INIT(home) };
  sdp_parser_t *parser = sdp_parse(home, original, osize, 0);
  sdp_printer_t *printer;
  int retval = 0;

  if (sdp_session(parser)) {
    sdp_session_t *sdp = sdp_session(parser);
    
    sdp->sdp_origin->o_version++;

    printer = sdp_print(home, sdp, buf, bsize, 0);

    if (sdp_message(printer)) {
      retval = sdp_message_size(printer);
    }
    else {
      fprintf(stderr, "increment_sdp_version: %s\n", 
              sdp_printing_error(printer));
    }

    sdp_printer_free(printer);
  }
  else {
    fprintf(stderr, "increment_sdp_version: %s\n", 
            sdp_parsing_error(p));
  }

  sdp_parser_free(parser);
      
  su_home_deinit(home);

  return retval;
}
@endcode

*/