cURL downloading images of camera (http request) - c++

Question

I have installed cURL, and I was able to download an image from website, and it works fine.
Here is the code:
#define CURL_STATICLIB
#include <stdio.h>
#include <stdlib.h>
#include </usr/include/curl/curl.h>
#include </usr/include/curl/stdcheaders.h>
#include </usr/include/curl/easy.h>
size_t write_data(void *ptr, size_t size, size_t nmemb, FILE *stream) {
size_t written = fwrite(ptr, size, nmemb, stream);
return written;
}
int main(void) {
CURL *curl;
FILE *fp;
CURLcode res;
char *url = "http://www.example.com/test_img.png";
char outfilename[FILENAME_MAX] = "/home/c++_proj/output/web_req_img.png";
curl = curl_easy_init();
if (curl) {
fp = fopen(outfilename,"wb");
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
res = curl_easy_perform(curl);
/* always cleanup */
curl_easy_cleanup(curl);
fclose(fp);
}
return 0;
}
I also have a dlink DCS-930L camera. I can easily connect my camera a static IP address, and I was able to view live video on the camera, by logging into the camera (e.g. http://192.168.1.5).
I don't need any special software or anything to start watch video.
Now, I would like to use cURL to download images from camera. But I am not sure how to do it.
Could someone please tell me, or provide some piece of code for it?
All I want to do is to capture (sample) few of the images that are being streamed.
How do I know when to make a request, and when would be the boundary between the images.
I would truly appreciate some advise and piece of code that could get me going.
T

Answer 1

According to the manual for this camera [1], you need use a Java or ActiveX plugin to receive and watch the video:
Please make sure that you have the latest version of Java application
installed on your computer to ensure proper operation when viewing the
video in Java mode. The Java application can be downloaded at no cost
from Sun’s web site (http://www.java.com).
When you connect to the home page of your camera, you will be prompted
to download ActiveX. If you want to use ActiveX to view your video
images instead of Java, then you must download ActiveX.
This suggests that grabbing the image is going to be more difficult than simply making an HTTP request.
[1] http://www.dlink.com/us/en/support/product/-/media/Consumer_Products/DCS/DCS%20930L/Manual/DCS%20930L_Manual_EN_US.pdf