---
name: "CURLOPT_INTERLEAVEDATA"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_INTERLEAVEDATA"
---

# CURLOPT\_INTERLEAVEDATA(3)

pointer passed to RTSP interleave callback

## NAME

CURLOPT\_INTERLEAVEDATA - pointer passed to RTSP interleave callback

## SYNOPSIS

```
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_INTERLEAVEDATA, void *pointer);
```

## DESCRIPTION

This is the userdata *pointer* that is passed to *[CURLOPT\_INTERLEAVEFUNCTION(3)](/CURLOPT_INTERLEAVEFUNCTION/3.md)* when interleaved RTP data is received. If the interleave function callback is not set, this pointer is not used anywhere.

## DEFAULT

NULL

## PROTOCOLS

This functionality affects rtsp only

## EXAMPLE

```
struct local {
  void *custom;
};
static size_t rtp_write(void *ptr, size_t size, size_t nmemb, void *userp)
{
  struct local *l = userp;
  printf("my pointer: %p\n", l->custom);
  /* take care of the packet in 'ptr', then return... */
  return size * nmemb;
}
int main(void)
{
  struct local rtp_data;
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode result;
    curl_easy_setopt(curl, CURLOPT_INTERLEAVEFUNCTION, rtp_write);
    curl_easy_setopt(curl, CURLOPT_INTERLEAVEDATA, &rtp_data);
    result = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}
```

## AVAILABILITY

Added in curl 7.20.0

## RETURN VALUE

*[curl\_easy\_setopt(3)](/curl_easy_setopt/3.md)* returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**CURLOPT\_INTERLEAVEFUNCTION**(3)](/CURLOPT_INTERLEAVEFUNCTION/3.md), [**CURLOPT\_RTSP\_REQUEST**(3)](/CURLOPT_RTSP_REQUEST/3.md)