Lines Matching full:control

14 control ioctls provide the information and a mechanism to create a nice
21 pre-defined control IDs have the prefix ``V4L2_CID_``, and are listed in
22 :ref:`control-id`. The ID is used when querying the attributes of a
23 control, and when getting or setting the current value.
26 assumptions about their purpose. Each control comes with a name string
36 value, step size or other menu items. A control with a certain *custom*
39 If a control is not applicable to the current configuration of the
43 Control values are stored globally, they do not change when switching
52 in order to always reflect the correct control value.
59 Control IDs
105     ``V4L2_CID_BRIGHTNESS``). This control is deprecated and should not
112     This is an action control. When set (the value is ignored), the
128     ``V4L2_CID_GAMMA``. This control is deprecated and should not be
135     Automatic gain/exposure control.
138     Gain control.
140     Primarily used to control gain on e.g. TV tuners but also on
141     webcams. Most devices control only digital gain with this control
166     Enables automatic hue control by the device. The effect of setting
167     ``V4L2_CID_HUE`` while automatic hue control is enabled is
171     This control specifies the white balance settings as a color
186     Chroma automatic gain control.
189     Adjusts the Chroma gain control (for use when chroma AGC is
244 	determined by ``V4L2_CID_COLORFX_CBCR`` control.
277     This is a read-only control that can be read by the application and
283     This is a read-only control that can be read by the application and
296     control lets you select the alpha component value of all pixels.
299     the device supports alpha channel processing this control lets you
304     End of the predefined control IDs (currently
308     ID of the first custom (driver specific) control. Applications
315 control value with the :ref:`VIDIOC_G_CTRL <VIDIOC_G_CTRL>` and
353 	    printf("Control %s\\n", queryctrl.name);
378 	    printf("Control %s\\n", query_ext_ctrl.name);
406 	    printf("Control %s\\n", queryctrl.name);
425 	    printf("Control %s\\n", queryctrl.name);
445     struct v4l2_control control;
460 	memset(&control, 0, sizeof (control));
461 	control.id = V4L2_CID_BRIGHTNESS;
462 	control.value = queryctrl.default_value;
464 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)) {
470     memset(&control, 0, sizeof(control));
471     control.id = V4L2_CID_CONTRAST;
473     if (0 == ioctl(fd, VIDIOC_G_CTRL, &control)) {
474 	control.value += 1;
478 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)
489     control.id = V4L2_CID_AUDIO_MUTE;
490     control.value = 1; /* silence */
493     ioctl(fd, VIDIOC_S_CTRL, &control);
499    since the meaning of the control with that ID is driver dependent. In