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CURLOPT_INTERLEAVEFUNCTION(curl_easy_setopt optioCURLOPT_INTERLEAVEFUNCTION(3)


NAME

       CURLOPT_INTERLEAVEFUNCTION  -  callback	function  for RTSP interleaved
       data


SYNOPSIS

       #include <curl/curl.h>

       size_t interleave_callback(void *ptr, size_t size, size_t nmemb,
				  void *userdata);

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_INTERLEAVEFUNCTION,
				 interleave_callback);


DESCRIPTION

       Pass a pointer to your callback function, which should match the proto-
       type shown above.

       This  callback  function  gets  called  by  libcurl  as	soon as it has
       received interleaved RTP data. This function gets  called  for  each  $
       block  and  therefore  contains	exactly  one upper-layer protocol unit
       (e.g.  one RTP packet). Curl writes the interleaved header as  well  as
       the included data for each call. The first byte is always an ASCII dol-
       lar sign. The dollar sign is followed by a one byte channel  identifier
       and  then  a  2	byte integer length in network byte order. See RFC2326
       Section 10.12 for more information on how RTP interleaving behaves.  If
       unset or set to NULL, curl will use the default write function.

       Interleaved RTP poses some challenges for the client application. Since
       the stream data is sharing the RTSP control connection, it is  critical
       to  service the RTP in a timely fashion. If the RTP data is not handled
       quickly, subsequent response processing may become unreasonably delayed
       and    the    connection   may	close.	 The   application   may   use
       CURL_RTSPREQ_RECEIVE to service RTP data when no requests are  desired.
       If the application makes a request, (e.g.  CURL_RTSPREQ_PAUSE) then the
       response handler will process any pending RTP data before  marking  the
       request as finished.

       The CURLOPT_INTERLEAVEDATA(3) is passed in the userdata argument in the
       callback.


DEFAULT

       NULL, the interleave data is then passed to the regular write function:
       CURLOPT_WRITEFUNCTION(3).


PROTOCOLS

       RTSP


EXAMPLE

       static size_t rtp_write(void *ptr, size_t size, size_t nmemb, void *user)
       {
	 struct local *l = (struct local *)user;
	 /* take care of the packet in 'ptr', then return... */
	 return size * nmemb;
       }
       {
	 struct local rtp_data;
	 curl_easy_setopt(curl, CURLOPT_INTERLEAVEFUNCTION, rtp_write);
	 curl_easy_setopt(curl, CURLOPT_INTERLEAVEDATA, &rtp_data);
       }


AVAILABILITY

       Added in 7.20.0


RETURN VALUE

       Returns	CURLE_OK  if the option is supported, and CURLE_UNKNOWN_OPTION
       if not.


SEE ALSO

       CURLOPT_INTERLEAVEDATA(3), CURLOPT_RTSP_REQUEST(3),

libcurl 7.63.0			August 11, 2018  CURLOPT_INTERLEAVEFUNCTION(3)

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