v4lapi.c

   1 /*
   2  * v4lapi.c -- api to the video4linux interface
   3  *
   4  * author: hackbard@hackdaworld.dyndns.org
   5  *
   6  */
   7
   8 #include <stdio.h>
   9 #include <sys/types.h>
  10 #include <sys/stat.h>
  11 #include <fcntl.h>
  12 #include <sys/ioctl.h>
  13
  14 #include <linux/videodev.h>
  15
  16 int v4l_init(char *dev) {
  17         int fd;
  18         struct video_capability vc;
  19         struct video_buffer vb;
  20         struct video_window vw;
  21
  22         if((fd=open(dev,O_RDONLY))<0) {
  23                 puts("open failed");
  24                 return -1;
  25         }
  26
  27         if(ioctl(fd,VIDIOCGCAP,&vc)<0) {
  28                 puts("ioctl VIDIOCGCAP failed");
  29                 return -1;
  30         }
  31
  32         printf("video device information:\n");
  33         printf("-------------------------\n\n");
  34         printf("interface name: %s\n\n",vc.name);
  35         printf("type:\n");
  36         printf("capture:\t %c\n",(vc.type&1)?'y':'n');
  37         printf("tuner:\t\t %c\n",((vc.type>>1)&1)?'y':'n');
  38         printf("teletext:\t %c\n",((vc.type>>2)&1)?'y':'n');
  39         printf("overlay:\t %c\n",((vc.type>>3)&1)?'y':'n');
  40         printf("chromakey:\t %c\n",((vc.type>>4)&1)?'y':'n');
  41         printf("clipping:\t %c\n",((vc.type>>5)&1)?'y':'n');
  42         printf("fb memory:\t %c\n",((vc.type>>6)&1)?'y':'n');
  43         printf("scalable:\t %c\n",((vc.type>>7)&1)?'y':'n');
  44         printf("monochrome:\t %c\n",((vc.type>>8)&1)?'y':'n');
  45         printf("subcapture:\t %c\n",((vc.type>>9)&1)?'y':'n');
  46         printf("decode: ");
  47         if((vc.type>>10)&1) printf("mpeg ");
  48         if((vc.type>>12)&1) printf("mjpeg ");
  49         printf("\n");
  50         printf("encode: ");
  51         if((vc.type>>11)&1) printf("mpeg ");
  52         if((vc.type>>13)&1) printf("mjpeg ");
  53         printf("\n\n");
  54         printf("channels:\t %d\n",vc.channels);
  55         printf("audios:\t\t %d\n",vc.audios);
  56         printf("width:\t\t %d - %d\n",vc.minwidth,vc.maxwidth);
  57         printf("height:\t\t %d - %d\n\n",vc.minheight,vc.maxheight);
  58
  59         if(ioctl(fd,VIDIOCGFBUF,&vb)<0)
  60                 puts("direct framebuffer access unsupported");
  61                 puts("");
  62         else {
  63                 printf("\n");
  64                 printf("framebuffer:\n");
  65                 printf("buffer addr:\t %d\n",vb.base);
  66                 printf("h: %d - w: %d - d: %d - bpl: %d\n\n",vb.height,vb.width,vb.depth,vb.bytesperline);
  67         }
  68
  69         if(ioctl(fd,VIDIOCGWIN,&vw)<0) {
  70                 puts("ioctl VIDIOCGWIN failed");
  71                 return -1;
  72         }
  73
  74         printf("capture area:\n");
  75         printf("x: %u - y: %u\n",vw.x,vw.y);
  76         printf("w: %u - h: %u\n",vw.width,vw.height);
  77         printf("
  78         return 1;
  79 }