/* * http://www.jollen.org * * v4l.c - the video4linux user space library * by 2001 Jollen <jollen@o3.net> */#include <stdio.h>#include <unistd.h>#include <error.h>#include <assert.h>#include <fcntl.h>#include <sys/ioctl.h>#include <sys/types.h>#include <sys/mman.h>#include <linux/videodev.h>#include "v4l.h"#define DEFAULT_DEVICE "/dev/video0"int v4l_open(char *dev, v4l_device *vd){   if (!dev)      dev = DEFAULT_DEVICE;   if ((vd->fd = open(dev, O_RDWR)) < 0) {      perror("v4l_open:");      return -1;   }   if (v4l_get_capability(vd))      return -1;   if (v4l_get_picture(vd))      return -1;   return 0;}int v4l_grab_picture(v4l_device *vd, unsigned int size){   if (read(vd->fd, &(vd->map), size) == 0) return -1;   return 0;}int v4l_get_capability(v4l_device *vd){   if (ioctl(vd->fd, VIDIOCGCAP, &(vd->capability)) < 0) {      perror("v4l_get_capability:");      return -1;   }   return 0;}/*   norm: VIDEO_MODE_PAL | VIDEO_MODE_NTSC | VIDEO_MODE_SECAM | VIDEO_MODE_AUTO   (see videodev.h)*/int v4l_set_norm(v4l_device *vd, int norm) {   int i;   for (i = 0; i < vd->capability.channels; i++) {      vd->channel[i].norm = norm;      //vd->channel[i].type = VIDEO_TYPE_TV;	//default (VIDEO_TYPE_TV | VIDEO_TYPE_CAMERA)   }   if (v4l_get_capability(vd)) {      perror("v4l_set_norm");      return -1;   }   if (v4l_get_picture(vd)) {      perror("v4l_set_norm");   }   return 0;}int v4l_get_channels(v4l_device *vd){   int i;   for (i = 0; i < vd->capability.channels; i++) {      vd->channel[i].channel = i;         if (ioctl(vd->fd, VIDIOCGCHAN, &(vd->channel[i])) < 0) {         perror("v4l_get_channel:");         return -1;      }   }   return 0;}/* * v4l_switch_channel - select (switch) the video source * * c: the channel number */int v4l_switch_channel(v4l_device *vd, int c){   if (ioctl(vd->fd, VIDIOCSCHAN, &(vd->channel[c])) < 0) {      perror("v4l_switch_channel:");      return -1;   }   return 0;}int v4l_get_audios(v4l_device *vd){   int i;   for (i = 0; i < vd->capability.audios; i++) {      vd->audio[i].audio = i;         if (ioctl(vd->fd, VIDIOCGAUDIO, &(vd->audio[i])) < 0) {         perror("v4l_get_audio:");         return -1;      }   }   return 0;}int v4l_get_picture(v4l_device *vd){   if (ioctl(vd->fd, VIDIOCGPICT, &(vd->picture)) < 0) {      perror("v4l_get_picture");      return -1;   }   return 0;}/* ...may be not necessarily... */int v4l_set_picture(v4l_device *vd, int br, int hue, int col, int cont,                     int white){   if (br) vd->picture.brightness = br;   if (hue) vd->picture.hue = hue;   if (col) vd->picture.colour = col;   if (cont) vd->picture.contrast = cont;   if (white) vd->picture.whiteness = white;   if(ioctl(vd->fd, VIDIOCSPICT, &(vd->picture)) < 0) {      perror("v4l_set_picture");      return -1;   }   return 0;}int v4l_close(v4l_device *vd){   close(vd->fd);   return 0;}int v4l_get_mbuf(v4l_device *vd){   if (ioctl(vd->fd, VIDIOCGMBUF, &(vd->mbuf)) < 0) {      perror("v4l_get_mbuf");      return -1;   }   return 0;}int v4l_mmap_init(v4l_device *vd){   //vd->mbuf.size = 0x151000;   //vd->mbuf.offsets[0] = 0;   if (v4l_get_mbuf(vd) < 0)      return -1;  if ((vd->map = mmap(0, vd->mbuf.size, PROT_READ|PROT_WRITE, MAP_SHARED, vd->fd, 0)) < 0) {      perror("v4l_mmap_init:mmap");      return -1; /*yangdaqian add * before vd->map in this statement */   }   return 0;}/* * v4l_grab_init - initalizate mmap buffer * * width: width of mmap's buffer * height: width of mmap's buffer */int v4l_grab_init(v4l_device *vd, int width, int height){   vd->mmap.width = width; //width;   vd->mmap.height = height; //height;   vd->mmap.format = vd->picture.palette;    vd->frame_current = 0;   vd->frame_using[0] = FALSE;   vd->frame_using[1] = FALSE;      return v4l_grab_frame(vd, 0);}/* * v4l_grab_frame - activate capturing * * frame: frame number to store image data */int v4l_grab_frame(v4l_device *vd, int frame){   if (vd->frame_using[frame]) {      fprintf(stderr, "v4l_grab_frame: frame %d is already used.\n", frame);      return -1;   }   vd->mmap.frame = frame;   if (ioctl(vd->fd, VIDIOCMCAPTURE, &(vd->mmap)) < 0) {      perror("v4l_grab_frame");      return -1;   }   vd->frame_using[frame] = TRUE;   vd->frame_current = frame;   return 0;}int v4l_grab_sync(v4l_device *vd) {   if (ioctl(vd->fd, VIDIOCSYNC, &(vd->frame_current)) < 0) {      perror("v4l_grab_sync");   }   vd->frame_using[vd->frame_current] = FALSE;   return 0;}int v4l_get_buffer(v4l_device *vd){   if (ioctl(vd->fd, VIDIOCGFBUF, &(vd->buffer)) < 0) {      perror("v4l_get_buffer");   }   return 0;}int v4l_set_buffer(v4l_device *vd){   if (ioctl(vd->fd, VIDIOCSFBUF, &(vd->buffer)) < 0) {      perror("v4l_set_buffer");      return -1;   }   return 0;}int v4l_set_palette(v4l_device *vd, int pal, int dep){   vd->picture.palette = pal;   vd->picture.depth = dep;   vd->mmap.format =pal;   if (ioctl(vd->fd, VIDIOCSPICT, &(vd->picture)) < 0) {      perror("v4l_set_palette");      return -1;   }   return 0;}