int readframe(void)
{
struct v4l2_buffer buf;
unsigned int i;
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:
return errnoexit ("VIDIOC_DQBUF");
}
}
assert (buf.index < n_buffers);
processimage (buffers[buf.index].start);
if (-1 == xioctl (fd, VIDIOC_QBUF, &buf))
return errnoexit ("VIDIOC_QBUF");
return 1;
}
int read_frame(int fd, buffer* frame_buffers, int width, int height,
int* rgb_buffer, int* y_buffer) {
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:
return errnoexit("VIDIOC_DQBUF");
}
}
assert(buf.index < BUFFER_COUNT);
yuyv422_to_argb(frame_buffers[buf.index].start, width, height, rgb_buffer,
y_buffer);
if(-1 == xioctl(fd, VIDIOC_QBUF, &buf)) {
return errnoexit("VIDIOC_QBUF");
}
return 1;
}
int startcapturing(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))
return errnoexit ("VIDIOC_QBUF");
}
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == xioctl (fd, VIDIOC_STREAMON, &type))
return errnoexit ("VIDIOC_STREAMON");
return SUCCESS_LOCAL;
}
int readframe(int i)
{
struct v4l2_buffer buf;
CLEAR (buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
if (-1 == xioctl (fd[i], VIDIOC_DQBUF, &buf)) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
default:
return errnoexit ("VIDIOC_DQBUF");
}
}
assert (buf.index < n_buffers[i]);
processimage (i, buffers[i][buf.index].start, buffers[i][buf.index].length);
if (-1 == xioctl (fd[i], VIDIOC_QBUF, &buf)){
LOGE("in readframe");
return errnoexit ("VIDIOC_QBUF");
}
return 1;
}
int initmmap(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) {
LOGE("%s does not support memory mapping", dev_name);
return ERROR_LOCAL;
} else {
return errnoexit ("VIDIOC_REQBUFS");
}
}
if (req.count < 2) {
LOGE("Insufficient buffer memory on %s", dev_name);
return ERROR_LOCAL;
}
buffers = calloc (req.count, sizeof (*buffers));
if (!buffers) {
LOGE("Out of memory");
return ERROR_LOCAL;
}
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))
return errnoexit ("VIDIOC_QUERYBUF");
buffers[n_buffers].length = buf.length;
buffers[n_buffers].start =
mmap (NULL ,
buf.length,
PROT_READ | PROT_WRITE,
MAP_SHARED,
fd, buf.m.offset);
if (MAP_FAILED == buffers[n_buffers].start)
return errnoexit ("mmap");
}
return SUCCESS_LOCAL;
}
int readframeonce(void) {
for (;;) {
fd_set fds;
struct timeval tv;
int r;
FD_ZERO(&fds);
FD_SET(fd, &fds);
tv.tv_sec = 2;
tv.tv_usec = 0;
r = select(fd + 1, &fds, NULL, NULL, &tv);
if (-1 == r) {
if (EINTR == errno)
continue;
return errnoexit("select");
}
if (0 == r) {
LOGE("select timeout");
return ERROR_LOCAL;
}
if (readframe() == 1)
break;
}
return SUCCESS_LOCAL;
}
int say(int socket, char *s)
{
int result = send(socket, s, strlen(s), 0);
if (result == -1)
errnoexit("Error talking to the client");
return result;
}
void process_camera(int fd, buffer* frame_buffers, int width,
int height, int* rgb_buffer, int* ybuf) {
if(fd == -1) {
return;
}
for(;;) {
fd_set fds;
FD_ZERO(&fds);
FD_SET(fd, &fds);
struct timeval tv;
tv.tv_sec = 2;
tv.tv_usec = 0;
int result = select(fd + 1, &fds, NULL, NULL, &tv);
if(-1 == result) {
if(EINTR == errno) {
continue;
}
errnoexit("select");
} else if(0 == result) {
LOGE("select timeout");
}
if(read_frame(fd, frame_buffers, width, height, rgb_buffer, ybuf) == 1) {
break;
}
}
}
int stop_capturing(int fd) {
enum v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if(-1 != fd && -1 == xioctl(fd, VIDIOC_STREAMOFF, &type)) {
return errnoexit("VIDIOC_STREAMOFF");
}
return SUCCESS_LOCAL;
}
int closedevice(void) {
if (-1 == close(fd)) {
fd = -1;
return errnoexit("close");
}
fd = -1;
return SUCCESS_LOCAL;
}
int closedevice(int i)
{
if (-1 == close (fd[i])){
fd[i] = -1;
return errnoexit ("close");
}
fd[i] = -1;
return SUCCESS_LOCAL;
}
int uninitdevice(void) {
unsigned int i;
for (i = 0; i < n_buffers; ++i)
if (-1 == munmap(buffers[i].start, buffers[i].length))
return errnoexit("munmap");
free(buffers);
return SUCCESS_LOCAL;
}
int stopcapturing(void) {
enum v4l2_buf_type type;
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == xioctl(fd, VIDIOC_STREAMOFF, &type))
return errnoexit("VIDIOC_STREAMOFF");
return SUCCESS_LOCAL;
}
int initdevice(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) {
LOGE("%s is no V4L2 device", dev_name);
return ERROR_LOCAL;
} else {
return errnoexit ("VIDIOC_QUERYCAP");
}
}
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
LOGE("%s is no video capture device", dev_name);
return ERROR_LOCAL;
}
if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
LOGE("%s does not support streaming i/o", dev_name);
return ERROR_LOCAL;
}
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;
if (-1 == xioctl (fd, VIDIOC_S_CROP, &crop)) {
switch (errno) {
case EINVAL:
break;
default:
break;
}
}
} else {
}
CLEAR (fmt);
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = IMG_WIDTH;
fmt.fmt.pix.height = IMG_HEIGHT;
fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
if (-1 == xioctl (fd, VIDIOC_S_FMT, &fmt))
return errnoexit ("VIDIOC_S_FMT");
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;
return initmmap ();
}
void error(char *msg)
{
errnoexit(msg);
exit(1);
}
