Old-school webcam by using server-push.

webcam.c

// webcam.c
// Author E. Martin
// July 27th 1997

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>


#define IMAGEPATH "../video/movie/auto.mpg qt%04d.jpg"
// $HTTP_headers =  "HTTP/1.1 200 OK\015\012";
// $HTTP_headers .=  "Connection: close\015\012";
// Connection: close\n
#define HEADER "HTTP/1.1 200 OK\nContent-type: multipart/x-mixed-replace;boundary=RandomEnough\n"
#define RANDOMSTRING "\n--RandomEnough\n"
#define ENDSTRING "\n--RandomEnough--\n"
#define CTSTRING "Content-type: image/jpeg\n\n"
#define STDOUT 1
#define IMGMAXSIZE 10000
#define IMGPATHLEN 100

#define noDEBUG

int main()
{
    struct stat fi;
	char buf[IMGMAXSIZE];
	char imgpath[IMGPATHLEN];
	double frame;
	int fd;
	int bytesread;
	time_t now;
	time_t then;
	int thenframe;
	double fps=5;


    if( write( STDOUT, HEADER, strlen( HEADER ) ) == -1 )
        exit(0);
    if( write( STDOUT, RANDOMSTRING, strlen( RANDOMSTRING ) ) == -1 )
        exit(0);

	then = time(NULL);
	frame = 1;
	thenframe = 1;
    while(1) {
		sprintf( imgpath, IMAGEPATH, (int) frame );
        stat( imgpath, &fi );
        if( ( fd = open( imgpath, O_RDONLY ) ) == -1) {
            exit(0);
        }
        if ( ( bytesread = read( fd, buf, fi.st_size ) ) <= 0 )
            exit(0);
        close(fd);
        if( write( STDOUT, CTSTRING, strlen( CTSTRING ) ) == -1 )
            exit(0);
        if( write( STDOUT, buf, fi.st_size ) == -1 )
            exit(0);
        if( write( STDOUT, RANDOMSTRING, strlen( RANDOMSTRING ) ) == -1 )
            exit(0);
		frame += (double) 5.0/fps;
		// fsync( STDOUT ); has no effect
		now = time(NULL);
		if ( difftime( then, now ) > 5 ) {
			fps = (double) (frame-thenframe)/5.0;
			thenframe = frame;
			then = now;
		}
		usleep( (unsigned long) 1000000/fps );
		// if usleep is unavailable, use select( 0, NULL, NULL, NULL, &tv );
    }
}