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
170     Enables automatic hue control by the device. The effect of setting
171     ``V4L2_CID_HUE`` while automatic hue control is enabled is
175     This control specifies the white balance settings as a color
190     Chroma automatic gain control.
193     Adjusts the Chroma gain control (for use when chroma AGC is
248 	determined by ``V4L2_CID_COLORFX_CBCR`` control.
251         by ``V4L2_CID_COLORFX_RGB`` control.
290     This is a read-only control that can be read by the application and
296     This is a read-only control that can be read by the application and
309     control lets you select the alpha component value of all pixels.
312     the device supports alpha channel processing this control lets you
317     End of the predefined control IDs (currently
321     ID of the first custom (driver specific) control. Applications
328 control value with the :ref:`VIDIOC_G_CTRL <VIDIOC_G_CTRL>` and
366 	    printf("Control %s\\n", queryctrl.name);
391 	    printf("Control %s\\n", query_ext_ctrl.name);
419 	    printf("Control %s\\n", queryctrl.name);
438 	    printf("Control %s\\n", queryctrl.name);
458     struct v4l2_control control;
473 	memset(&control, 0, sizeof (control));
474 	control.id = V4L2_CID_BRIGHTNESS;
475 	control.value = queryctrl.default_value;
477 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)) {
483     memset(&control, 0, sizeof(control));
484     control.id = V4L2_CID_CONTRAST;
486     if (0 == ioctl(fd, VIDIOC_G_CTRL, &control)) {
487 	control.value += 1;
491 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)
502     control.id = V4L2_CID_AUDIO_MUTE;
503     control.value = 1; /* silence */
506     ioctl(fd, VIDIOC_S_CTRL, &control);
512    since the meaning of the control with that ID is driver dependent. In