demos/c_simple/v4l2_grab.c

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2012 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23  /*
  24
  25    Gets an image from v4l2 device.
  26
  27   */
  28
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <stdio.h>
  32
  33 #include <GP.h>
  34
  35 static int get_image(const char *filename, GP_Grabber *grabber)
  36 {
  37         /* turn on grabber */
  38         if (GP_GrabberStart(grabber)) {
  39                 fprintf(stderr, "Failed to start grabber\n");
  40                 return 1;
  41         }
  42
  43         /* throw away first frame, it's usually wrong */
  44         while (!GP_GrabberPoll(grabber))
  45                 usleep(100000);
  46
  47         while (!GP_GrabberPoll(grabber))
  48                 usleep(100000);
  49
  50         /* save image */
  51         if (GP_SaveJPG(grabber->frame, filename, NULL)) {
  52                 fprintf(stderr, "Failed to save image '%s': %s",
  53                         filename, strerror(errno));
  54                 return 1;
  55         }
  56
  57         /* turn off grabber */
  58         if (GP_GrabberStop(grabber)) {
  59                 fprintf(stderr, "Failed to start grabber\n");
  60                 return 1;
  61         }
  62
  63         return 0;
  64 }
  65
  66 int main(int argc, char *argv[])
  67 {
  68         const char *v4l2_device = "/dev/video0";
  69         const char *image_filename = "frame.jpg";
  70         unsigned int w = 640, h = 480;
  71         int secs = 0;
  72         int opt;
  73
  74         while ((opt = getopt(argc, argv, "d:hH:o:W:l:s:")) != -1) {
  75                 switch (opt) {
  76                 case 'o':
  77                         image_filename = optarg;
  78                 break;
  79                 case 'd':
  80                         v4l2_device = optarg;
  81                 break;
  82                 case 'W':
  83                         w = atoi(optarg);
  84                 break;
  85                 case 'H':
  86                         h = atoi(optarg);
  87                 break;
  88                 case 's':
  89                         secs = atoi(optarg);
  90                 break;
  91                 case 'l':
  92                         GP_SetDebugLevel(atoi(optarg));
  93                 break;
  94                 case 'h':
  95                         printf("Usage; %s opts\n", argv[0]);
  96                         printf("-o  output image file, default is 'frame.jpg'\n"
  97                                "-d  v4l2 device name (default is '/dev/video0'\n"
  98                                "-W  output image width, default is 640\n"
  99                                "-H  output image height, default is 480\n"
 100                                "-l  sets GFXprim debug level (default is 0)\n"
 101                                "-s  take image every s seconds (the images are stored as frameX.jpg)\n"
 102                                "-h  prints this help\n");
 103                         return 0;
 104                 break;
 105                 default:
 106                         fprintf(stderr, "Invalid paramter '%c'\n", opt);
 107                         return 1;
 108                 }
 109         }
 110
 111         GP_Grabber *grabber = GP_GrabberV4L2Init(v4l2_device, w, h);
 112
 113         if (grabber == NULL) {
 114                 fprintf(stderr, "Failed to initalize grabber '%s': %s\n",
 115                         v4l2_device, strerror(errno));
 116                 return 1;
 117         }
 118
 119         if (secs == 0) {
 120                 get_image(image_filename, grabber);
 121                 GP_GrabberExit(grabber);
 122                 return 0;
 123         }
 124
 125         int i = 0;
 126
 127         for (;;) {
 128                 char buf[128];
 129
 130                 snprintf(buf, sizeof(buf), "frame%03i.jpg", i++);
 131
 132                 if (get_image(buf, grabber)) {
 133                         fprintf(stderr, "Failed to get image, exitting...\n");
 134                         return 1;
 135                 }
 136
 137                 sleep(secs);
 138         }
 139
 140
 141         return 0;
 142 }