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
163     Enables automatic hue control by the device. The effect of setting
164     ``V4L2_CID_HUE`` while automatic hue control is enabled is
168     This control specifies the white balance settings as a color
183     Chroma automatic gain control.
186     Adjusts the Chroma gain control (for use when chroma AGC is
241 	determined by ``V4L2_CID_COLORFX_CBCR`` control.
274     This is a read-only control that can be read by the application and
280     This is a read-only control that can be read by the application and
293     control lets you select the alpha component value of all pixels.
296     the device supports alpha channel processing this control lets you
301     End of the predefined control IDs (currently
305     ID of the first custom (driver specific) control. Applications
312 control value with the :ref:`VIDIOC_G_CTRL <VIDIOC_G_CTRL>` and
350 	    printf("Control %s\\n", queryctrl.name);
375 	    printf("Control %s\\n", query_ext_ctrl.name);
403 	    printf("Control %s\\n", queryctrl.name);
422 	    printf("Control %s\\n", queryctrl.name);
442     struct v4l2_control control;
457 	memset(&control, 0, sizeof (control));
458 	control.id = V4L2_CID_BRIGHTNESS;
459 	control.value = queryctrl.default_value;
461 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)) {
467     memset(&control, 0, sizeof(control));
468     control.id = V4L2_CID_CONTRAST;
470     if (0 == ioctl(fd, VIDIOC_G_CTRL, &control)) {
471 	control.value += 1;
475 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)
486     control.id = V4L2_CID_AUDIO_MUTE;
487     control.value = 1; /* silence */
490     ioctl(fd, VIDIOC_S_CTRL, &control);
496    since the meaning of the control with that ID is driver dependent. In