mmvideotest_cpp.txt

LINUX内核编程的一些程序例子

/** mmvideo.cpp
 * 
 * author marco corvi
 * date   may 2003
 *
 * application test for mmvideo driver
 *  
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h> // getopt
#include <string.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>

#include <linux/videodev.h>

#define DIMX 384
#define DIMY 288
#define SIZE DIMX*DIMY*3

#include "gui++.h"
#include "Image_JPG.h"

unsigned char image[DIMX*DIMY];
int back_image[DIMX*DIMY];

char * device = "/dev/video0";  // 81,0

int main( int argc, char ** argv )
{
  int fd;
  unsigned char buffer[SIZE];
  int n;
  int size = SIZE;
  char * image_file = "logo.jpg";
  
  if ( argc > 1 )
    image_file = argv[1];

  GUI gui(1, DIMX, DIMY );

  fd = open( device,  O_RDWR );
  if ( fd < 0 ) {
    char * strerr = strerror(errno);
    printf( "open() error %d %s \n", errno, strerr );
    exit(0);
  }
  printf( "open fd %d \n", fd );

  Image_JPG logo( image_file );
  printf("Image %d x %d \n", logo.width(), logo.height() );
  // swap Red and Blue
  unsigned char * logo_image = logo.image();
  /*
  unsigned char tmp;
  for (unsigned int k=0; k<logo.width() * logo.height(); k++ ) {
    tmp = *(logo_image + 3 * k);
    *(logo_image + 3 * k) = *(logo_image + 3 * k+2);
    *(logo_image + 3 * k+2) = tmp;
  }
  */
  gui.displayImage( logo_image, DIMX, DIMY, 0, 0, 3);
  sleep( 1 );

  n = write( fd, logo_image, size );
  printf("Written %d bytes to device \n", n );

  for (int cnt=0; cnt<1000; cnt++) {
    /*
    int frame = count % 2;
    if ( (n = ioctl( fd, VIDIOCSYNC, &frame) ) < 0 ) {
      printf("Failed ioctl(%d) errno %d\n", frame, errno);
    }
    */

    if ( (n = read( fd, buffer, size)) < 0 ) {
      char * strerr = strerror(errno);
      printf( "read() error %d %s \n", errno, strerr );
      break;
    }
   
    // printf("%3d: read %d bytes from device \n", cnt, n );
    gui.displayImage( buffer, DIMX, DIMY, 0, 0, 3);

    // gui.displayImage( image, DIMX, DIMY, 0, 0, 1);

    // gui.waitMsecs( 100 );
  }
  close( fd );

}