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FloatImg
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videograb : first step

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master
Tonton Th 4 years ago
parent f0f8daa0fb
commit c054054ee5
5 changed files with 355 additions and 9 deletions
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  1. 2
      .gitignore
  2. 11
      v4l2/Makefile
  3. 317
      v4l2/funcs.c
  4. 7
      v4l2/funcs.h
  5. 27
      v4l2/t.c

2
.gitignore vendored
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@ -9,6 +9,8 @@ gmon.out
*.fimg
essai
*/*.ps
v4l2/t
v4l2/capture
v4l2/*.o

11
v4l2/Makefile
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@ -3,13 +3,14 @@
COPT = -Wall -fpic -g -DDEBUG_LEVEL=1
DEPS = ../floatimg.h ../libfloatimg.a Makefile
funcs.o: funcs.c funcs.h Makefile
gcc ${COPT} -c $<
t: t.c Makefile ${DEPS} funcs.o
gcc ${COPT} $< funcs.o ../libfloatimg.a -o $@
t: t.c Makefile ${DEPS}
gcc ${COPT} $< ../libfloatimg.a -o $@
# --------
# extern things
# ---------------
# external things
capture: capture.c Makefile
gcc -Wall $< -o $@

317
v4l2/funcs.c
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@ -0,0 +1,317 @@
/*
* 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>
/* --------------------------------------------------------------------- */
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 no 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;
}

7
v4l2/funcs.h
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@ -0,0 +1,7 @@
/*
* V4L2 functions - header file
*/
int open_device(char *dev_name);
int init_device(int notused);

27
v4l2/t.c
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@ -8,10 +8,26 @@
#include <math.h>
#include <string.h>
#include "funcs.h"
#include "floatimg.h"
int verbosity;
/* --------------------------------------------------------------------- */
int essai(char *dev, int k)
{
int vfd, foo;
fprintf(stderr, ">>> %s ( '%s' %d )\n", __func__, dev, k);
vfd = open_device(dev);
fprintf(stderr, "\topen %s -> %d\n", dev, vfd);
foo = init_device(0);
fprintf(stderr, "\tinit -> %d\n", foo);
return k;
}
/* --------------------------------------------------------------------- */
void help(int k)
{
@ -23,16 +39,16 @@ puts("\t-v\tincrease verbosity");
exit(0);
}
/* --------------------------------------------------------------------- */
int main(int argc, char *argv[])
{
int foo, opt;
int W = 800, H = 600;
double tb;
char *device = "/dev/video0";
int K = 0;
while ((opt = getopt(argc, argv, "hK:v")) != -1) {
while ((opt = getopt(argc, argv, "d:hK:v")) != -1) {
switch(opt) {
case 'd': device = optarg; break;
case 'h': help(0); break;
case 'K': K = atol(optarg); break;
case 'v': verbosity++; break;
@ -41,6 +57,9 @@ while ((opt = getopt(argc, argv, "hK:v")) != -1) {
if (verbosity) fimg_print_version(0);
foo = essai(device, K);
fprintf(stderr, "\tessai -> %d\n", foo);
return 0;
}
/* --------------------------------------------------------------------- */

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