322 lines
7.5 KiB
C
322 lines
7.5 KiB
C
/*
|
|
* V4L2 functions - ugly source code
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include <fcntl.h> /* low-level i/o */
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/ioctl.h>
|
|
|
|
#include <linux/videodev2.h>
|
|
|
|
#include "../floatimg.h"
|
|
|
|
#include "funcs.h"
|
|
|
|
/* --------------------------------------------------------------------- */
|
|
|
|
extern int verbosity;
|
|
|
|
enum io_method {
|
|
IO_METHOD_READ,
|
|
IO_METHOD_MMAP,
|
|
IO_METHOD_USERPTR,
|
|
};
|
|
|
|
struct buffer {
|
|
void *start;
|
|
size_t length;
|
|
};
|
|
|
|
static char *dev_name;
|
|
static enum io_method io = IO_METHOD_MMAP;
|
|
static int fd = -1;
|
|
struct buffer *buffers;
|
|
static unsigned int n_buffers;
|
|
static int out_buf;
|
|
static int force_format;
|
|
static int frame_count = 70;
|
|
|
|
static void errno_exit(const char *s)
|
|
{
|
|
fprintf(stderr, "%s error %d, %s\n", s, errno, strerror(errno));
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
static int xioctl(int fh, int request, void *arg)
|
|
{
|
|
int r;
|
|
|
|
do {
|
|
r = ioctl(fh, request, arg);
|
|
} while (-1 == r && EINTR == errno);
|
|
|
|
return r;
|
|
}
|
|
|
|
/* --------------------------------------------------------------------- */
|
|
/*
|
|
*
|
|
*/
|
|
int open_device(char *device)
|
|
{
|
|
struct stat st;
|
|
|
|
if (-1 == stat(device, &st)) {
|
|
fprintf(stderr, "Cannot identify '%s': %d, %s\n",
|
|
device, errno, strerror(errno));
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
if (!S_ISCHR(st.st_mode)) {
|
|
fprintf(stderr, "%s is no device\n", device);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
fd = open(device, O_RDWR /* required */ | O_NONBLOCK, 0);
|
|
|
|
if (-1 == fd) {
|
|
fprintf(stderr, "Cannot open '%s': %d, %s\n",
|
|
device, errno, strerror(errno));
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
dev_name = strdup(device); /* XXX */
|
|
|
|
return fd;
|
|
}
|
|
/* --------------------------------------------------------------------- */
|
|
static void init_read(unsigned int buffer_size)
|
|
{
|
|
buffers = calloc(1, sizeof(*buffers));
|
|
|
|
if (!buffers) {
|
|
fprintf(stderr, "Out of memory\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
buffers[0].length = buffer_size;
|
|
buffers[0].start = malloc(buffer_size);
|
|
|
|
if (!buffers[0].start) {
|
|
fprintf(stderr, "Out of memory\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
}
|
|
|
|
static void init_mmap(void)
|
|
{
|
|
struct v4l2_requestbuffers req;
|
|
|
|
memset(&req, 0, sizeof(req));
|
|
|
|
req.count = 4;
|
|
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
|
|
req.memory = V4L2_MEMORY_MMAP;
|
|
|
|
if (-1 == xioctl(fd, VIDIOC_REQBUFS, &req)) {
|
|
if (EINVAL == errno) {
|
|
fprintf(stderr, "%s does not support "
|
|
"memory mapping\n", dev_name);
|
|
exit(EXIT_FAILURE);
|
|
} else {
|
|
errno_exit("VIDIOC_REQBUFS");
|
|
}
|
|
}
|
|
|
|
if (req.count < 2) {
|
|
fprintf(stderr, "Insufficient buffer memory on %s\n",
|
|
dev_name);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
buffers = calloc(req.count, sizeof(*buffers));
|
|
|
|
if (!buffers) {
|
|
fprintf(stderr, "Out of memory\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
for (n_buffers = 0; n_buffers < req.count; ++n_buffers) {
|
|
struct v4l2_buffer buf;
|
|
|
|
memset(&buf, 0, sizeof(buf));
|
|
|
|
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
|
|
buf.memory = V4L2_MEMORY_MMAP;
|
|
buf.index = n_buffers;
|
|
|
|
if (-1 == xioctl(fd, VIDIOC_QUERYBUF, &buf))
|
|
errno_exit("VIDIOC_QUERYBUF");
|
|
|
|
buffers[n_buffers].length = buf.length;
|
|
buffers[n_buffers].start =
|
|
mmap(NULL /* start anywhere */,
|
|
buf.length,
|
|
PROT_READ | PROT_WRITE /* required */,
|
|
MAP_SHARED /* recommended */,
|
|
fd, buf.m.offset);
|
|
|
|
if (MAP_FAILED == buffers[n_buffers].start)
|
|
errno_exit("mmap");
|
|
}
|
|
}
|
|
|
|
static void init_userp(unsigned int buffer_size)
|
|
{
|
|
struct v4l2_requestbuffers req;
|
|
|
|
memset(&req, 0, sizeof(req));
|
|
|
|
req.count = 4;
|
|
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
|
|
req.memory = V4L2_MEMORY_USERPTR;
|
|
|
|
if (-1 == xioctl(fd, VIDIOC_REQBUFS, &req)) {
|
|
if (EINVAL == errno) {
|
|
fprintf(stderr, "%s does not support "
|
|
"user pointer i/o\n", dev_name);
|
|
exit(EXIT_FAILURE);
|
|
} else {
|
|
errno_exit("VIDIOC_REQBUFS");
|
|
}
|
|
}
|
|
|
|
buffers = calloc(4, sizeof(*buffers));
|
|
|
|
if (!buffers) {
|
|
fprintf(stderr, "Out of memory\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
for (n_buffers = 0; n_buffers < 4; ++n_buffers) {
|
|
buffers[n_buffers].length = buffer_size;
|
|
buffers[n_buffers].start = malloc(buffer_size);
|
|
|
|
if (!buffers[n_buffers].start) {
|
|
fprintf(stderr, "Out of memory\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
}
|
|
}
|
|
/* --------------------------------------------------------------------- */
|
|
int init_device(int notused)
|
|
{
|
|
struct v4l2_capability cap;
|
|
struct v4l2_cropcap cropcap;
|
|
struct v4l2_crop crop;
|
|
struct v4l2_format fmt;
|
|
unsigned int min;
|
|
|
|
#if DEBUG_LEVEL
|
|
fprintf(stderr, ">>> %s ( %d )\n", __func__, notused);
|
|
#endif
|
|
|
|
if (-1 == xioctl(fd, VIDIOC_QUERYCAP, &cap)) {
|
|
if (EINVAL == errno) {
|
|
fprintf(stderr, "%s is not a V4L2 device\n", dev_name);
|
|
exit(EXIT_FAILURE);
|
|
} else {
|
|
errno_exit("VIDIOC_QUERYCAP");
|
|
}
|
|
}
|
|
|
|
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
|
|
fprintf(stderr, "%s is no video capture device\n", dev_name);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
switch (io) {
|
|
case IO_METHOD_READ:
|
|
if (!(cap.capabilities & V4L2_CAP_READWRITE)) {
|
|
fprintf(stderr, "%s do not support read i/o\n", dev_name);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
if (verbosity) fprintf(stderr, "%s io method read OK\n", __func__);
|
|
break;
|
|
|
|
case IO_METHOD_MMAP:
|
|
case IO_METHOD_USERPTR:
|
|
if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
|
|
fprintf(stderr, "%s do not support streaming i/o\n", dev_name);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
if (verbosity) fprintf(stderr, "%s io mmap/userptr OK\n", __func__);
|
|
break;
|
|
} /* end switch */
|
|
|
|
/* Select video input, video standard and tune here. */
|
|
|
|
|
|
memset(&cropcap, 0, sizeof(cropcap));
|
|
|
|
cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
|
|
|
|
if (0 == xioctl(fd, VIDIOC_CROPCAP, &cropcap)) {
|
|
crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
|
|
crop.c = cropcap.defrect; /* reset to default */
|
|
|
|
if (-1 == xioctl(fd, VIDIOC_S_CROP, &crop)) {
|
|
switch (errno) {
|
|
case EINVAL:
|
|
/* Cropping not supported. */
|
|
break;
|
|
default:
|
|
/* Errors ignored. */
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
/* Errors ignored. */
|
|
}
|
|
|
|
|
|
memset(&fmt, 0, sizeof(fmt)); // CLEAR(fmt);
|
|
|
|
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
|
|
if (force_format) {
|
|
fmt.fmt.pix.width = 640;
|
|
fmt.fmt.pix.height = 480;
|
|
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
|
|
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
|
|
|
|
if (-1 == xioctl(fd, VIDIOC_S_FMT, &fmt))
|
|
errno_exit("VIDIOC_S_FMT");
|
|
|
|
/* Note VIDIOC_S_FMT may change width and height. */
|
|
} else {
|
|
/* Preserve original settings as set by v4l2-ctl for example */
|
|
if (-1 == xioctl(fd, VIDIOC_G_FMT, &fmt))
|
|
errno_exit("VIDIOC_G_FMT");
|
|
}
|
|
|
|
/* Buggy driver paranoia. */
|
|
min = fmt.fmt.pix.width * 2;
|
|
if (fmt.fmt.pix.bytesperline < min)
|
|
fmt.fmt.pix.bytesperline = min;
|
|
min = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height;
|
|
if (fmt.fmt.pix.sizeimage < min)
|
|
fmt.fmt.pix.sizeimage = min;
|
|
|
|
switch (io) {
|
|
case IO_METHOD_READ:
|
|
init_read(fmt.fmt.pix.sizeimage);
|
|
break;
|
|
|
|
case IO_METHOD_MMAP:
|
|
init_mmap();
|
|
break;
|
|
|
|
case IO_METHOD_USERPTR:
|
|
init_userp(fmt.fmt.pix.sizeimage);
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|