Bibliothèque de traitements d'images en virgule flottante. http://la.buvette.org/photos/cumul/
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/* V4L2 video picture grabber
Origin :V4L2GRAB.C - patched by tTh
Copyright (C) 2009 Mauro Carvalho Chehab <mchehab@infradead.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <linux/videodev2.h>
#include <libv4l2.h>
#include "../floatimg.h"
#define CLEAR(x) memset(&(x), 0, sizeof(x))
struct buffer {
void *start;
size_t length;
};
int verbosity;
/* --------------------------------------------------------------------- */
static void xioctl(int fh, int request, void *arg)
{
int r;
do {
r = v4l2_ioctl(fh, request, arg);
} while (r == -1 && ((errno == EINTR) || (errno == EAGAIN)));
if (r == -1) {
fprintf(stderr, "error %d, %s\n", errno, strerror(errno));
exit(EXIT_FAILURE);
}
}
/* --------------------------------------------------------------------- */
void help(int v)
{
puts("options :");
puts("\t-d /dev/?\tselect video device");
puts("\t-n NNN\t\thow many frames ?");
puts("\t-p NNN\t\tperiod in seconds");
puts("\t-v\t\tincrease verbosity");
exit(0);
}
/* --------------------------------------------------------------------- */
int main(int argc, char **argv)
{
struct v4l2_format fmt;
struct v4l2_buffer buf;
struct v4l2_requestbuffers req;
enum v4l2_buf_type type;
fd_set fds;
struct timeval tv;
int r, fd = -1;
unsigned int i, n_buffers;
char *dev_name = "/dev/video0";
char out_name[256];
FILE *fout;
struct buffer *buffers;
int period = 10; /* delai entre les captures */
int nbre_capt = 1; /* nombre de captures */
int opt;
double t_debut, t_final;
while ((opt = getopt(argc, argv, "d:hn:p:v")) != -1) {
switch(opt) {
case 'd': dev_name = optarg; break;
case 'h': help(0); break;
case 'n': nbre_capt = atoi(optarg); break;
case 'p': period = atoi(optarg); break;
case 'v': verbosity++; break;
}
}
fd = v4l2_open(dev_name, O_RDWR | O_NONBLOCK, 0);
if (fd < 0) {
perror("Cannot open device");
exit(EXIT_FAILURE);
}
CLEAR(fmt);
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = 640;
fmt.fmt.pix.height = 480;
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB24;
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
xioctl(fd, VIDIOC_S_FMT, &fmt);
if (fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_RGB24) {
printf("Libv4l didn't accept RGB24 format. Can't proceed.\n");
exit(EXIT_FAILURE);
}
if ((fmt.fmt.pix.width != 640) || (fmt.fmt.pix.height != 480)) {
printf("Warning: driver is sending image at %dx%d\n",
fmt.fmt.pix.width, fmt.fmt.pix.height);
}
CLEAR(req);
req.count = 2;
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
req.memory = V4L2_MEMORY_MMAP;
xioctl(fd, VIDIOC_REQBUFS, &req);
buffers = calloc(req.count, sizeof(*buffers));
for (n_buffers = 0; n_buffers < req.count; ++n_buffers) {
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = n_buffers;
xioctl(fd, VIDIOC_QUERYBUF, &buf);
buffers[n_buffers].length = buf.length;
buffers[n_buffers].start = v4l2_mmap(NULL, buf.length,
PROT_READ | PROT_WRITE, MAP_SHARED,
fd, buf.m.offset);
if (MAP_FAILED == buffers[n_buffers].start) {
perror("mmap");
exit(EXIT_FAILURE);
}
}
t_debut = fimg_timer_set(0);
for (i = 0; i < n_buffers; ++i) {
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = i;
xioctl(fd, VIDIOC_QBUF, &buf);
}
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
xioctl(fd, VIDIOC_STREAMON, &type);
for (i = 0; i < nbre_capt; i++) {
do {
FD_ZERO(&fds);
FD_SET(fd, &fds);
/* Timeout. */
tv.tv_sec = 2;
tv.tv_usec = 0;
r = select(fd + 1, &fds, NULL, NULL, &tv);
} while ((r == -1 && (errno = EINTR)));
if (r == -1) {
perror("select");
return errno;
}
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
xioctl(fd, VIDIOC_DQBUF, &buf);
sprintf(out_name, "out%03d.ppm", i);
if (verbosity) fprintf(stderr, "--> %s\n", out_name);
fout = fopen(out_name, "w");
if (!fout) {
perror("Cannot open image");
exit(EXIT_FAILURE);
}
fprintf(fout, "P6\n%d %d 255\n",
fmt.fmt.pix.width, fmt.fmt.pix.height);
fwrite(buffers[buf.index].start, buf.bytesused, 1, fout);
fclose(fout);
if (nbre_capt > 1 && period) {
sleep(period);
}
xioctl(fd, VIDIOC_QBUF, &buf);
}
t_final = fimg_timer_get(0);
fprintf(stderr, "elapsed time %g s.\n", t_final);
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
xioctl(fd, VIDIOC_STREAMOFF, &type);
for (i = 0; i < n_buffers; ++i) {
v4l2_munmap(buffers[i].start, buffers[i].length);
}
v4l2_close(fd);
return 0;
}