Lines Matching full:control

21 control ioctls provide the information and a mechanism to create a nice
28 pre-defined control IDs have the prefix ``V4L2_CID_``, and are listed in
29 :ref:`control-id`. The ID is used when querying the attributes of a
30 control, and when getting or setting the current value.
33 assumptions about their purpose. Each control comes with a name string
43 value, step size or other menu items. A control with a certain *custom*
46 If a control is not applicable to the current configuration of the
50 Control values are stored globally, they do not change when switching
59 in order to always reflect the correct control value.
66 Control IDs
112     ``V4L2_CID_BRIGHTNESS``). This control is deprecated and should not
119     This is an action control. When set (the value is ignored), the
135     ``V4L2_CID_GAMMA``. This control is deprecated and should not be
142     Automatic gain/exposure control.
145     Gain control.
147     Primarily used to control gain on e.g. TV tuners but also on
148     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.
281     This is a read-only control that can be read by the application and
287     This is a read-only control that can be read by the application and
300     control lets you select the alpha component value of all pixels.
303     the device supports alpha channel processing this control lets you
308     End of the predefined control IDs (currently
312     ID of the first custom (driver specific) control. Applications
319 control value with the :ref:`VIDIOC_G_CTRL <VIDIOC_G_CTRL>` and
357 	    printf("Control %s\\n", queryctrl.name);
382 	    printf("Control %s\\n", query_ext_ctrl.name);
410 	    printf("Control %s\\n", queryctrl.name);
429 	    printf("Control %s\\n", queryctrl.name);
449     struct v4l2_control control;
464 	memset(&control, 0, sizeof (control));
465 	control.id = V4L2_CID_BRIGHTNESS;
466 	control.value = queryctrl.default_value;
468 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)) {
474     memset(&control, 0, sizeof(control));
475     control.id = V4L2_CID_CONTRAST;
477     if (0 == ioctl(fd, VIDIOC_G_CTRL, &control)) {
478 	control.value += 1;
482 	if (-1 == ioctl(fd, VIDIOC_S_CTRL, &control)
493     control.id = V4L2_CID_AUDIO_MUTE;
494     control.value = 1; /* silence */
497     ioctl(fd, VIDIOC_S_CTRL, &control);
503    since the meaning of the control with that ID is driver dependent. In