static int video_prepare_capture(struct device *dev, int nbufs, unsigned int offset,
const char *filename)
{
unsigned int i;
int ret;
/* Allocate and map buffers. */
if ((ret = video_alloc_buffers(dev, nbufs, offset)) < 0)
return ret;
if (dev->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
ret = video_load_test_pattern(dev, filename);
if (ret < 0)
return ret;
}
/* Queue the buffers. */
for (i = 0; i < dev->nbufs; ++i) {
ret = video_queue_buffer(dev, i);
if (ret < 0)
return ret;
}
return 0;
}
int video_prepare_capture(struct device *dev, int nbufs, unsigned int offset,
const char *filename, enum buffer_fill_mode fill)
{
unsigned int padding;
unsigned int i;
int ret;
/* Allocate and map buffers. */
padding = (fill & BUFFER_FILL_PADDING) ? 4096 : 0;
if ((ret = video_alloc_buffers(dev, nbufs, offset, padding)) < 0)
return ret;
if (dev->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
ret = video_load_test_pattern(dev, filename);
if (ret < 0)
return ret;
}
/* Queue the buffers. */
for (i = 0; i < dev->nbufs; ++i) {
ret = video_queue_buffer(dev, i, fill);
if (ret < 0)
return ret;
}
return 0;
}
static int uvc_drv_command(ErlDrvData handle, unsigned int command, char *buf,
int len, char **rbuf, int rlen) {
Uvc* d = (Uvc*) handle;
switch(command) {
case CMD_OPEN: {
if(len != sizeof(Config)) {
driver_failure_atom(d->port, "invalid_config");
return 0;
}
Config *cfg = (Config *)buf;
char device_path[1024];
snprintf(device_path, sizeof(device_path), "/dev/video%d", cfg->device);
d->fd = open(device_path, O_RDWR);
if(d->fd == -1) {
driver_failure_posix(d->port, errno);
return 0;
}
struct v4l2_capability cap;
memset(&cap, 0, sizeof cap);
int ret;
ret = ioctl(d->fd, VIDIOC_QUERYCAP, &cap);
if (ret < 0) {
driver_failure_posix(d->port, errno);
return 0;
}
if(!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
driver_failure_atom(d->port, "not_a_capture_device");
return 0;
}
fprintf(stderr, "Setting size %dx%d\r\n", cfg->width, cfg->height);
struct v4l2_format fmt;
memset(&fmt, 0, sizeof fmt);
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if(cfg->width > 640 || cfg->height > 480) {
d->pixelformat = V4L2_PIX_FMT_MJPEG;
} else {
d->pixelformat = V4L2_PIX_FMT_YUYV;
}
d->width = cfg->width;
d->height = cfg->height;
fmt.fmt.pix.width = cfg->width;
fmt.fmt.pix.height = cfg->height;
fmt.fmt.pix.pixelformat = d->pixelformat;
fmt.fmt.pix.field = V4L2_FIELD_ANY;
ret = ioctl(d->fd, VIDIOC_S_FMT, &fmt);
if (ret < 0) {
driver_failure_posix(d->port, errno);
return 0;
}
fprintf(stderr, "Setting fps %d\r\n", cfg->fps);
struct v4l2_streamparm parm;
memset(&parm, 0, sizeof parm);
parm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
ret = ioctl(d->fd, VIDIOC_G_PARM, &parm);
if (ret < 0) {
driver_failure_posix(d->port, errno);
return 0;
}
parm.parm.capture.timeperframe.numerator = 1;
parm.parm.capture.timeperframe.denominator = cfg->fps;
ret = ioctl(d->fd, VIDIOC_S_PARM, &parm);
if (ret < 0) {
driver_failure_posix(d->port, errno);
return 0;
}
fprintf(stderr, "Setting quality 100\r\n");
struct v4l2_jpegcompression jpeg;
memset(&jpeg, 0, sizeof jpeg);
jpeg.quality = 90;
ret = ioctl(d->fd, VIDIOC_S_JPEGCOMP, &jpeg);
if (ret < 0) {
// driver_failure_posix(d->port, errno);
// return 0;
fprintf(stderr, "Failed to set quality\r\n");
}
if(video_alloc_buffers(d) < 0) {
driver_failure_posix(d->port, errno);
return 0;
}
int type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
ret = ioctl(d->fd, VIDIOC_STREAMON, &type);
if(ret < 0) {
driver_failure_posix(d->port, errno);
return 0;
}
fprintf(stderr, "Capture started\r\n");
driver_select(d->port, (ErlDrvEvent)d->fd, DO_READ, 1);
memcpy(*rbuf, "ok", 2);
return 2;
}
break;
default:
return 0;
}
return 0;
}
