Lines Matching full:control

15 control ioctls provide the information and a mechanism to create a nice
22 pre-defined control IDs have the prefix ``V4L2_CID_``, and are listed in
23 :ref:`control-id`. The ID is used when querying the attributes of a
24 control, and when getting or setting the current value.
27 assumptions about their purpose. Each control comes with a name string
37 value, step size or other menu items. A control with a certain *custom*
40 If a control is not applicable to the current configuration of the
44 Control values are stored globally, they do not change when switching
53 in order to always reflect the correct control value.
60 Control IDs
106     ``V4L2_CID_BRIGHTNESS``). This control is deprecated and should not
113     This is an action control. When set (the value is ignored), the
129     ``V4L2_CID_GAMMA``. This control is deprecated and should not be
136     Automatic gain/exposure control.
139     Gain control.
141     Primarily used to control gain on e.g. TV tuners but also on
142     webcams. Most devices control only digital gain with this control
171     Enables automatic hue control by the device. The effect of setting
172     ``V4L2_CID_HUE`` while automatic hue control is enabled is
176     This control specifies the white balance settings as a color
191     Chroma automatic gain control.
194     Adjusts the Chroma gain control (for use when chroma AGC is
249 	determined by ``V4L2_CID_COLORFX_CBCR`` control.
252         by ``V4L2_CID_COLORFX_RGB`` control.
291     This is a read-only control that can be read by the application and
294     necessary for hardware to work. This control is required for stateful
298     This is a read-only control that can be read by the application and
301     necessary for hardware to work. This control is required for stateful
312     control lets you select the alpha component value of all pixels.
315     the device supports alpha channel processing this control lets you
320     End of the predefined control IDs (currently
324     ID of the first custom (driver specific) control. Applications
331 control value with the :ref:`VIDIOC_G_CTRL <VIDIOC_G_CTRL>` and
369 	    printf("Control %s\\n", queryctrl.name);
394 	    printf("Control %s\\n", query_ext_ctrl.name);
422 	    printf("Control %s\\n", queryctrl.name);
441 	    printf("Control %s\\n", queryctrl.name);
461     struct v4l2_control control;
476 	memset(&control, 0, sizeof (control));
477 	control.id = V4L2_CID_BRIGHTNESS;
478 	control.value = queryctrl.default_value;
480 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)) {
486     memset(&control, 0, sizeof(control));
487     control.id = V4L2_CID_CONTRAST;
489     if (0 == ioctl(fd, VIDIOC_G_CTRL, &control)) {
490 	control.value += 1;
494 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)
505     control.id = V4L2_CID_AUDIO_MUTE;
506     control.value = 1; /* silence */
509     ioctl(fd, VIDIOC_S_CTRL, &control);
515    since the meaning of the control with that ID is driver dependent. In