/*
* v4l2.c
*
* Created on: Aug 8, 2011
* Author: gavin
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <getopt.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <malloc.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <asm/types.h>
#include <linux/videodev2.h>
#include <jpeglib.h>
#include <linux/fb.h>
#include "v4l2.h"
#include "shm.h"
struct buffer {
void * start;
size_t length;
};
int fd = -1;
struct buffer * buffers = NULL;
static unsigned int n_buffers = 0;
// global settings
static unsigned int width = 640;
static unsigned int height = 480;
static unsigned char jpegQuality = 70;
static char* deviceName = "/dev/video0";
static int fb_bpp;
static int cam_fp = -1;
static int fb_fp = -1;
static char *fb_addr = NULL;
static int shm_fd;
void deviceOpen(void)
{
struct stat st;
// stat file
if (-1 == stat(deviceName, &st)) {
fprintf(stderr, "Cannot identify '%s': %d, %s\n", deviceName, errno, strerror (errno));
exit(EXIT_FAILURE);
}
// check if its device
if (!S_ISCHR (st.st_mode)) {
fprintf(stderr, "%s is no device\n", deviceName);
exit(EXIT_FAILURE);
}
// open device
fd = open(deviceName, O_RDWR /* required */ | O_NONBLOCK, 0);
// check if opening was successfull
if (-1 == fd) {
fprintf(stderr, "Cannot open '%s': %d, %s\n", deviceName, errno, strerror (errno));
exit(EXIT_FAILURE);
}
shm_fd = create_shm();
}
/**
initialize device
*/
void deviceInit(void)
{
struct v4l2_capability cap;
struct v4l2_cropcap cropcap;
struct v4l2_crop crop;
struct v4l2_format fmt;
unsigned int min;
if (-1 == xioctl(fd, VIDIOC_QUERYCAP, &cap)) {
if (EINVAL == errno) {
fprintf(stderr, "%s is no V4L2 device\n",deviceName);
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_QUERYCAP");
}
}
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE))
{
fprintf(stderr, "%s is no video capture device\n",deviceName);
exit(EXIT_FAILURE);
}
if (!(cap.capabilities & V4L2_CAP_STREAMING))
{
fprintf(stderr, "%s does not support streaming i/o\n",deviceName);
exit(EXIT_FAILURE);
}
/* Select video input, video standard and tune here. */
CLEAR(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. */
}
CLEAR (fmt);
// v4l2_format
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = 800;
fmt.fmt.pix.height = 480;
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB32;
// fmt.fmt.pix.field = V4L2_FIELD_ANY;
if (-1 == xioctl(fd, VIDIOC_S_FMT, &fmt))
errno_exit("VIDIOC_S_FMT");
/* Note VIDIOC_S_FMT may change width and height. */
if (width != fmt.fmt.pix.width) {
width = fmt.fmt.pix.width;
fprintf(stderr,"Image width set to %i by device %s.\n",width,deviceName);
}
if (height != fmt.fmt.pix.height) {
height = fmt.fmt.pix.height;
fprintf(stderr,"Image height set to %i by device %s.\n",height,deviceName);
}
/* 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;
mmapInit();
}
void mmapInit(void)
{
struct v4l2_requestbuffers req;
CLEAR (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", deviceName);
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_REQBUFS");
}
}
if (req.count < 2) {
fprintf(stderr, "Insufficient buffer memory on %s\n", deviceName);
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;
CLEAR (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");
}
}
void captureStart(void)
{
unsigned int i;
enum v4l2_buf_type type;
for (i = 0; i < n_buffers; ++i)
{
struct v4l2_buffer buf;
CLEAR (buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = i;
if (-1 == xioctl(fd, VIDIOC_QBUF, &buf))
errno_exit("VIDIOC_QBUF");
}
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == xioctl(fd, VIDIOC_STREAMON, &type))
errno_exit("VIDIOC_STREAMON");
}
void mainLoop(void)
{
unsigned int count;
count = 1;
while (count-- > 0) {
for (;;) {
fd_set fds;
struct timeval tv;
int r;
FD_ZERO(&fds);
FD_SET(fd, &fds);
/* Timeout. */
tv.tv_sec = 2;
tv.tv_usec = 0;
r = select(fd + 1, &fds, NULL, NULL, &tv);
if (-1 == r) {
if (EINTR == errno)
continue;
errno_exit("select");
}
if (0 == r) {
fprintf (stderr, "select timeout\n");
exit(EXIT_FAILURE);
}
if (frameRead())
break;
}
}
}
unsigned char* frameRead(void)
{
struct v4l2_buffer buf;
CLEAR (buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
if (-1 == xioctl(fd, VIDIOC_DQBUF, &buf)) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
default:
errno_exit("VIDIOC_DQBUF");
}
}
assert (buf.index < n_buffers);
imageProcess(buffers[buf.index].start);
if (-1 == xioctl(fd, VIDIOC_QBUF, &buf))
errno_exit("VIDIOC_QBUF");
return (unsigned char*)buffers[buf.index].start;
}
static void jpegWrite(unsigned char* img)
{
struct jpeg_compress_struct cinfo;
struct jpeg_error_mgr jerr;
JSAMPROW row_pointer[1];
FILE *outfile = fopen( "1.jpg", "wb" );
// try to open file for saving
if (!outfile) {
errno_exit("jpeg");
}
// create jpeg data
cinfo.err = jpeg_std_error( &jerr );
jpeg_create_compress(&cinfo);
jpeg_stdio_dest(&cinfo, outfile);
// set image parameters
cinfo.image_width = 800;
cinfo.image_height = 480;
cinfo.input_components = 3;
cinfo.in_color_space = JCS_RGB;
// set jpeg compression parameters to default
jpeg_set_defaults(&cinfo);
// and then adjust quality setting
jpeg_set_quality(&cinfo, jpegQuality, TRUE);
// start compress
jpeg_start_compress(&cinfo, TRUE);
// feed data
while (cinfo.next_scanline < cinfo.image_height) {
// row_pointer[0] = &img[cinfo.next_scanline * cinfo.image_width * cinfo.input_components];
row_pointer[0] = &img[(cinfo.image_height - cinfo.next_scanline - 1) * cinfo.image_width*3];
jpeg_write_scanlines(&cinfo, row_pointer, 1);
}
// finish compression
jpeg_finish_compress(&cinfo);
// destroy jpeg data
jpeg_destroy_compress(&cinfo);
// close output file
fclose(outfile);
}
void imageProcess(const void* p)
{
char buff[5];
rcv_shm(shm_fd, buff);
int
