cap_libv4l.cpp v4l2_buffer- & gt; отметка времени всегда равна 0

static double icvGetPropertyCAM_V4L (CvCaptureCAM_V4L* capture,
int property_id ) {
char name[32];
int is_v4l2_device = 0;
/* initialize the control structure */
switch (property_id) {
case CV_CAP_PROP_FRAME_WIDTH:
case CV_CAP_PROP_FRAME_HEIGHT:
CLEAR (capture->form);
capture->form.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == xioctl (capture->deviceHandle, VIDIOC_G_FMT, &capture->form)) {
/* display an error message, and return an error code */
perror ("VIDIOC_G_FMT");
if (v4l1_ioctl (capture->deviceHandle, VIDIOCGWIN, &capture->captureWindow) < 0) {
fprintf (stderr, "HIGHGUI ERROR: V4L: Unable to determine size of incoming image\n");
icvCloseCAM_V4L(capture);
return -1;
} else {
int retval = (property_id == CV_CAP_PROP_FRAME_WIDTH)?capture->captureWindow.width:capture->captureWindow.height;
return retval / 0xFFFF;
}
}
return (property_id == CV_CAP_PROP_FRAME_WIDTH)?capture->form.fmt.pix.width:capture->form.fmt.pix.height;
case CV_CAP_PROP_BRIGHTNESS:
sprintf(name, "Brightness");
capture->control.id = V4L2_CID_BRIGHTNESS;
break;
case CV_CAP_PROP_CONTRAST:
sprintf(name, "Contrast");
capture->control.id = V4L2_CID_CONTRAST;
break;
case CV_CAP_PROP_SATURATION:
sprintf(name, "Saturation");
capture->control.id = V4L2_CID_SATURATION;
break;
case CV_CAP_PROP_HUE:
sprintf(name, "Hue");
capture->control.id = V4L2_CID_HUE;
break;
case CV_CAP_PROP_GAIN:
sprintf(name, "Gain");
capture->control.id = V4L2_CID_GAIN;
break;
case CV_CAP_PROP_EXPOSURE:
sprintf(name, "Exposure");
capture->control.id = V4L2_CID_EXPOSURE;
break;
case CV_CAP_PROP_POS_MSEC:
if (capture->FirstCapture) {
return 0;
} else {
return 1000 * capture->timestamp.tv_sec + ((double) capture->timestamp.tv_usec) / 1000;
}
break;
default:
sprintf(name, "<unknown property string>");
capture->control.id = property_id;
}

if(v4l2_ioctl(capture->deviceHandle, VIDIOC_G_CTRL, &capture->control) == 0) {
/* all went well */
is_v4l2_device = 1;
} else {
fprintf(stderr, "HIGHGUI ERROR: V4L2: Unable to get property %s(%u) - %s\n", name, capture->control.id, strerror(errno));
}

if (is_v4l2_device == 1) {
/* get the min/max values */
int v4l2_min = v4l2_get_ctrl_min(capture, capture->control.id);
int v4l2_max = v4l2_get_ctrl_max(capture, capture->control.id);

if ((v4l2_min == -1) && (v4l2_max == -1)) {
fprintf(stderr, "HIGHGUI ERROR: V4L2: Property %s(%u) not supported by device\n", name, property_id);
return -1;
}

/* all was OK, so convert to 0.0 - 1.0 range, and return the value */
return ((float)capture->control.value - v4l2_min) / (v4l2_max - v4l2_min);

} else {
/* TODO: review this section */
int retval = -1;

switch (property_id) {
case CV_CAP_PROP_BRIGHTNESS:
retval = capture->imageProperties.brightness;
break;
case CV_CAP_PROP_CONTRAST:
retval = capture->imageProperties.contrast;
break;
case CV_CAP_PROP_SATURATION:
retval = capture->imageProperties.colour;
break;
case CV_CAP_PROP_HUE:
retval = capture->imageProperties.hue;
break;
case CV_CAP_PROP_GAIN:
fprintf(stderr, "HIGHGUI ERROR: V4L: Gain control in V4L is not supported\n");
return -1;
break;
case CV_CAP_PROP_EXPOSURE:
fprintf(stderr, "HIGHGUI ERROR: V4L: Exposure control in V4L is not supported\n");
return -1;
break;
}

if (retval == -1) {
/* there was a problem */
return -1;
}
/* all was OK, so convert to 0.0 - 1.0 range, and return the value */
return float (retval) / 0xFFFF;
}
}