] sphinx.addnodesdocument)}( rawsource children](translations
LanguagesNode)}(hhh](h pending_xref)}(hhh]docutils.nodesTextChinese (Simplified)}parenthsba
attributes}(ids]classes]names]dupnames]backrefs] refdomainstdreftypedoc reftarget8/translations/zh_CN/userspace-api/media/drivers/uvcvideomodnameN classnameNrefexplicitutagnamehhhubh)}(hhh]hChinese (Traditional)}hh2sbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget8/translations/zh_TW/userspace-api/media/drivers/uvcvideomodnameN classnameNrefexplicituh1hhhubh)}(hhh]hItalian}hhFsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget8/translations/it_IT/userspace-api/media/drivers/uvcvideomodnameN classnameNrefexplicituh1hhhubh)}(hhh]hJapanese}hhZsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget8/translations/ja_JP/userspace-api/media/drivers/uvcvideomodnameN classnameNrefexplicituh1hhhubh)}(hhh]hKorean}hhnsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget8/translations/ko_KR/userspace-api/media/drivers/uvcvideomodnameN classnameNrefexplicituh1hhhubh)}(hhh]hPortuguese (Brazilian)}hhsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget8/translations/pt_BR/userspace-api/media/drivers/uvcvideomodnameN classnameNrefexplicituh1hhhubh)}(hhh]hSpanish}hhsbah}(h]h ]h"]h$]h&] refdomainh)reftypeh+ reftarget8/translations/sp_SP/userspace-api/media/drivers/uvcvideomodnameN classnameNrefexplicituh1hhhubeh}(h]h ]h"]h$]h&]current_languageEnglishuh1h
hh _documenthsourceNlineNubhcomment)}(h SPDX-License-Identifier: GPL-2.0h]h SPDX-License-Identifier: GPL-2.0}hhsbah}(h]h ]h"]h$]h&] xml:spacepreserveuh1hhhhhhR/var/lib/git/docbuild/linux/Documentation/userspace-api/media/drivers/uvcvideo.rsthKubhsection)}(hhh](htitle)}(h&The Linux USB Video Class (UVC) driverh]h&The Linux USB Video Class (UVC) driver}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhhhhhKubh paragraph)}(h|This file documents some driver-specific aspects of the UVC driver, such as
driver-specific ioctls and implementation notes.h]h|This file documents some driver-specific aspects of the UVC driver, such as
driver-specific ioctls and implementation notes.}(hhhhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhhhhubh)}(hkQuestions and remarks can be sent to the Linux UVC development mailing list at
linux-media@vger.kernel.org.h](hOQuestions and remarks can be sent to the Linux UVC development mailing list at
}(hhhhhNhNubh reference)}(hlinux-media@vger.kernel.orgh]hlinux-media@vger.kernel.org}(hhhhhNhNubah}(h]h ]h"]h$]h&]refuri"mailto:linux-media@vger.kernel.orguh1hhhubh.}(hhhhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhK hhhhubh)}(hhh](h)}(hExtension Unit (XU) supporth]hExtension Unit (XU) support}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hhhhhKubh)}(hhh](h)}(hIntroductionh]hIntroduction}(hj% hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj" hhhhhKubh)}(hThe UVC specification allows for vendor-specific extensions through extension
units (XUs). The Linux UVC driver supports extension unit controls (XU controls)
through two separate mechanisms:h]hThe UVC specification allows for vendor-specific extensions through extension
units (XUs). The Linux UVC driver supports extension unit controls (XU controls)
through two separate mechanisms:}(hj3 hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj" hhubhblock_quote)}(h_- through mappings of XU controls to V4L2 controls
- through a driver-specific ioctl interface
h]hbullet_list)}(hhh](h list_item)}(h0through mappings of XU controls to V4L2 controlsh]h)}(hjP h]h0through mappings of XU controls to V4L2 controls}(hjR hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjN ubah}(h]h ]h"]h$]h&]uh1jL hjI ubjM )}(h*through a driver-specific ioctl interface
h]h)}(h)through a driver-specific ioctl interfaceh]h)through a driver-specific ioctl interface}(hji hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhje ubah}(h]h ]h"]h$]h&]uh1jL hjI ubeh}(h]h ]h"]h$]h&]bullet-uh1jG hhhKhjC ubah}(h]h ]h"]h$]h&]uh1jA hhhKhj" hhubh)}(hThe first one allows generic V4L2 applications to use XU controls by mapping
certain XU controls onto V4L2 controls, which then show up during ordinary
control enumeration.h]hThe first one allows generic V4L2 applications to use XU controls by mapping
certain XU controls onto V4L2 controls, which then show up during ordinary
control enumeration.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj" hhubh)}(hThe second mechanism requires uvcvideo-specific knowledge for the application to
access XU controls but exposes the entire UVC XU concept to user space for
maximum flexibility.h]hThe second mechanism requires uvcvideo-specific knowledge for the application to
access XU controls but exposes the entire UVC XU concept to user space for
maximum flexibility.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj" hhubh)}(hMBoth mechanisms complement each other and are described in more detail below.h]hMBoth mechanisms complement each other and are described in more detail below.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK"hj" hhubeh}(h]introductionah ]h"]introductionah$]h&]uh1hhj hhhhhKubh)}(hhh](h)}(hControl mappingsh]hControl mappings}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hhhhhK&ubh)}(hX The UVC driver provides an API for user space applications to define so-called
control mappings at runtime. These allow for individual XU controls or byte
ranges thereof to be mapped to new V4L2 controls. Such controls appear and
function exactly like normal V4L2 controls (i.e. the stock controls, such as
brightness, contrast, etc.). However, reading or writing of such a V4L2 controls
triggers a read or write of the associated XU control.h]hX The UVC driver provides an API for user space applications to define so-called
control mappings at runtime. These allow for individual XU controls or byte
ranges thereof to be mapped to new V4L2 controls. Such controls appear and
function exactly like normal V4L2 controls (i.e. the stock controls, such as
brightness, contrast, etc.). However, reading or writing of such a V4L2 controls
triggers a read or write of the associated XU control.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK(hj hhubh)}(hXJ The ioctl used to create these control mappings is called UVCIOC_CTRL_MAP.
Previous driver versions (before 0.2.0) required another ioctl to be used
beforehand (UVCIOC_CTRL_ADD) to pass XU control information to the UVC driver.
This is no longer necessary as newer uvcvideo versions query the information
directly from the device.h]hXJ The ioctl used to create these control mappings is called UVCIOC_CTRL_MAP.
Previous driver versions (before 0.2.0) required another ioctl to be used
beforehand (UVCIOC_CTRL_ADD) to pass XU control information to the UVC driver.
This is no longer necessary as newer uvcvideo versions query the information
directly from the device.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK/hj hhubh)}(hdFor details on the UVCIOC_CTRL_MAP ioctl please refer to the section titled
"IOCTL reference" below.h]hhFor details on the UVCIOC_CTRL_MAP ioctl please refer to the section titled
“IOCTL reference” below.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK5hj hhubhenumerated_list)}(hhh]jM )}(h%Driver specific XU control interface
h]h)}(h$Driver specific XU control interfaceh]h$Driver specific XU control interface}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK9hj ubah}(h]h ]h"]h$]h&]uh1jL hj hhhhhNubah}(h]h ]h"]h$]h&]enumtypearabicprefixhsuffix.startKuh1j hj hhhhhK9ubh)}(hFor applications that need to access XU controls directly, e.g. for testing
purposes, firmware upload, or accessing binary controls, a second mechanism to
access XU controls is provided in the form of a driver-specific ioctl, namely
UVCIOC_CTRL_QUERY.h]hFor applications that need to access XU controls directly, e.g. for testing
purposes, firmware upload, or accessing binary controls, a second mechanism to
access XU controls is provided in the form of a driver-specific ioctl, namely
UVCIOC_CTRL_QUERY.}(hj! hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK;hj hhubh)}(hA call to this ioctl allows applications to send queries to the UVC driver that
directly map to the low-level UVC control requests.h]hA call to this ioctl allows applications to send queries to the UVC driver that
directly map to the low-level UVC control requests.}(hj/ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK@hj hhubh)}(hXP In order to make such a request the UVC unit ID of the control's extension unit
and the control selector need to be known. This information either needs to be
hardcoded in the application or queried using other ways such as by parsing the
UVC descriptor or, if available, using the media controller API to enumerate a
device's entities.h]hXT In order to make such a request the UVC unit ID of the control’s extension unit
and the control selector need to be known. This information either needs to be
hardcoded in the application or queried using other ways such as by parsing the
UVC descriptor or, if available, using the media controller API to enumerate a
device’s entities.}(hj= hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKChj hhubh)}(hX Unless the control size is already known it is necessary to first make a
UVC_GET_LEN requests in order to be able to allocate a sufficiently large buffer
and set the buffer size to the correct value. Similarly, to find out whether
UVC_GET_CUR or UVC_SET_CUR are valid requests for a given control, a
UVC_GET_INFO request should be made. The bits 0 (GET supported) and 1 (SET
supported) of the resulting byte indicate which requests are valid.h]hX Unless the control size is already known it is necessary to first make a
UVC_GET_LEN requests in order to be able to allocate a sufficiently large buffer
and set the buffer size to the correct value. Similarly, to find out whether
UVC_GET_CUR or UVC_SET_CUR are valid requests for a given control, a
UVC_GET_INFO request should be made. The bits 0 (GET supported) and 1 (SET
supported) of the resulting byte indicate which requests are valid.}(hjK hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKIhj hhubh)}(hX' With the addition of the UVCIOC_CTRL_QUERY ioctl the UVCIOC_CTRL_GET and
UVCIOC_CTRL_SET ioctls have become obsolete since their functionality is a
subset of the former ioctl. For the time being they are still supported but
application developers are encouraged to use UVCIOC_CTRL_QUERY instead.h]hX' With the addition of the UVCIOC_CTRL_QUERY ioctl the UVCIOC_CTRL_GET and
UVCIOC_CTRL_SET ioctls have become obsolete since their functionality is a
subset of the former ioctl. For the time being they are still supported but
application developers are encouraged to use UVCIOC_CTRL_QUERY instead.}(hjY hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKPhj hhubh)}(hfFor details on the UVCIOC_CTRL_QUERY ioctl please refer to the section titled
"IOCTL reference" below.h]hjFor details on the UVCIOC_CTRL_QUERY ioctl please refer to the section titled
“IOCTL reference” below.}(hjg hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKUhj hhubeh}(h]control-mappingsah ]h"]control mappingsah$]h&]uh1hhj hhhhhK&ubh)}(hhh](h)}(hSecurityh]hSecurity}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj} hhhhhKZubh)}(hThe API doesn't currently provide a fine-grained access control facility. The
UVCIOC_CTRL_ADD and UVCIOC_CTRL_MAP ioctls require super user permissions.h]hThe API doesn’t currently provide a fine-grained access control facility. The
UVCIOC_CTRL_ADD and UVCIOC_CTRL_MAP ioctls require super user permissions.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK\hj} hhubh)}(h/Suggestions on how to improve this are welcome.h]h/Suggestions on how to improve this are welcome.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK_hj} hhubeh}(h]securityah ]h"]securityah$]h&]uh1hhj hhhhhKZubh)}(hhh](h)}(h Debuggingh]h Debugging}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hhhhhKcubh)}(hIn order to debug problems related to XU controls or controls in general it is
recommended to enable the UVC_TRACE_CONTROL bit in the module parameter 'trace'.
This causes extra output to be written into the system log.h]hIn order to debug problems related to XU controls or controls in general it is
recommended to enable the UVC_TRACE_CONTROL bit in the module parameter ‘trace’.
This causes extra output to be written into the system log.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKehj hhubeh}(h] debuggingah ]h"] debuggingah$]h&]uh1hhj hhhhhKcubh)}(hhh](h)}(hIOCTL referenceh]hIOCTL reference}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hhhhhKkubh)}(hhh](h)}(h5UVCIOC_CTRL_MAP - Map a UVC control to a V4L2 controlh]h5UVCIOC_CTRL_MAP - Map a UVC control to a V4L2 control}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hhhhhKnubh)}(h'Argument: struct uvc_xu_control_mappingh]h'Argument: struct uvc_xu_control_mapping}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKphj hhubh)}(h**Description**:h](hstrong)}(h**Description**h]hDescription}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j
hj ubh:}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKrhj hhubjB )}(hX0 This ioctl creates a mapping between a UVC control or part of a UVC
control and a V4L2 control. Once mappings are defined, userspace
applications can access vendor-defined UVC control through the V4L2
control API.
To create a mapping, applications fill the uvc_xu_control_mapping
structure with information about an existing UVC control defined with
UVCIOC_CTRL_ADD and a new V4L2 control.
A UVC control can be mapped to several V4L2 controls. For instance,
a UVC pan/tilt control could be mapped to separate pan and tilt V4L2
controls. The UVC control is divided into non overlapping fields using
the 'size' and 'offset' fields and are then independently mapped to
V4L2 control.
For signed integer V4L2 controls the data_type field should be set to
UVC_CTRL_DATA_TYPE_SIGNED. Other values are currently ignored.
h](h)}(hThis ioctl creates a mapping between a UVC control or part of a UVC
control and a V4L2 control. Once mappings are defined, userspace
applications can access vendor-defined UVC control through the V4L2
control API.h]hThis ioctl creates a mapping between a UVC control or part of a UVC
control and a V4L2 control. Once mappings are defined, userspace
applications can access vendor-defined UVC control through the V4L2
control API.}(hj+ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKthj' ubh)}(hTo create a mapping, applications fill the uvc_xu_control_mapping
structure with information about an existing UVC control defined with
UVCIOC_CTRL_ADD and a new V4L2 control.h]hTo create a mapping, applications fill the uvc_xu_control_mapping
structure with information about an existing UVC control defined with
UVCIOC_CTRL_ADD and a new V4L2 control.}(hj9 hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKyhj' ubh)}(hX! A UVC control can be mapped to several V4L2 controls. For instance,
a UVC pan/tilt control could be mapped to separate pan and tilt V4L2
controls. The UVC control is divided into non overlapping fields using
the 'size' and 'offset' fields and are then independently mapped to
V4L2 control.h]hX) A UVC control can be mapped to several V4L2 controls. For instance,
a UVC pan/tilt control could be mapped to separate pan and tilt V4L2
controls. The UVC control is divided into non overlapping fields using
the ‘size’ and ‘offset’ fields and are then independently mapped to
V4L2 control.}(hjG hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhK}hj' ubh)}(hFor signed integer V4L2 controls the data_type field should be set to
UVC_CTRL_DATA_TYPE_SIGNED. Other values are currently ignored.h]hFor signed integer V4L2 controls the data_type field should be set to
UVC_CTRL_DATA_TYPE_SIGNED. Other values are currently ignored.}(hjU hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj' ubeh}(h]h ]h"]h$]h&]uh1jA hhhKthj hhubh)}(h**Return value**:h](j )}(h**Return value**h]hReturn value}(hjm hhhNhNubah}(h]h ]h"]h$]h&]uh1j
hji ubh:}(hji hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj hhubjB )}(hXu On success 0 is returned. On error -1 is returned and errno is set
appropriately.
ENOMEM
Not enough memory to perform the operation.
EPERM
Insufficient privileges (super user privileges are required).
EINVAL
No such UVC control.
EOVERFLOW
The requested offset and size would overflow the UVC control.
EEXIST
Mapping already exists.
h](h)}(hQOn success 0 is returned. On error -1 is returned and errno is set
appropriately.h]hQOn success 0 is returned. On error -1 is returned and errno is set
appropriately.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubhdefinition_list)}(hhh](hdefinition_list_item)}(h2ENOMEM
Not enough memory to perform the operation.h](hterm)}(hENOMEMh]hENOMEM}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubh
definition)}(hhh]h)}(h+Not enough memory to perform the operation.h]h+Not enough memory to perform the operation.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hCEPERM
Insufficient privileges (super user privileges are required).h](j )}(hEPERMh]hEPERM}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(h=Insufficient privileges (super user privileges are required).h]h=Insufficient privileges (super user privileges are required).}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hEINVAL
No such UVC control.h](j )}(hEINVALh]hEINVAL}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(hNo such UVC control.h]hNo such UVC control.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hGEOVERFLOW
The requested offset and size would overflow the UVC control.h](j )}(h EOVERFLOWh]h EOVERFLOW}(hj3 hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj/ ubj )}(hhh]h)}(h=The requested offset and size would overflow the UVC control.h]h=The requested offset and size would overflow the UVC control.}(hjD hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjA ubah}(h]h ]h"]h$]h&]uh1j hj/ ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hEEXIST
Mapping already exists.
h](j )}(hEEXISTh]hEEXIST}(hjb hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj^ ubj )}(hhh]h)}(hMapping already exists.h]hMapping already exists.}(hjs hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjp ubah}(h]h ]h"]h$]h&]uh1j hj^ ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubeh}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1jA hhhKhj hhubh)}(h**Data types**:h](j )}(h**Data types**h]h
Data types}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j
hj ubh:}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj hhubh
literal_block)}(hXO * struct uvc_xu_control_mapping
__u32 id V4L2 control identifier
__u8 name[32] V4L2 control name
__u8 entity[16] UVC extension unit GUID
__u8 selector UVC control selector
__u8 size V4L2 control size (in bits)
__u8 offset V4L2 control offset (in bits)
enum v4l2_ctrl_type
v4l2_type V4L2 control type
enum uvc_control_data_type
data_type UVC control data type
struct uvc_menu_info
*menu_info Array of menu entries (for menu controls only)
__u32 menu_count Number of menu entries (for menu controls only)
* struct uvc_menu_info
__u32 value Menu entry value used by the device
__u8 name[32] Menu entry name
* enum uvc_control_data_type
UVC_CTRL_DATA_TYPE_RAW Raw control (byte array)
UVC_CTRL_DATA_TYPE_SIGNED Signed integer
UVC_CTRL_DATA_TYPE_UNSIGNED Unsigned integer
UVC_CTRL_DATA_TYPE_BOOLEAN Boolean
UVC_CTRL_DATA_TYPE_ENUM Enumeration
UVC_CTRL_DATA_TYPE_BITMASK Bitmask
UVC_CTRL_DATA_TYPE_RECT Rectangular areah]hXO * struct uvc_xu_control_mapping
__u32 id V4L2 control identifier
__u8 name[32] V4L2 control name
__u8 entity[16] UVC extension unit GUID
__u8 selector UVC control selector
__u8 size V4L2 control size (in bits)
__u8 offset V4L2 control offset (in bits)
enum v4l2_ctrl_type
v4l2_type V4L2 control type
enum uvc_control_data_type
data_type UVC control data type
struct uvc_menu_info
*menu_info Array of menu entries (for menu controls only)
__u32 menu_count Number of menu entries (for menu controls only)
* struct uvc_menu_info
__u32 value Menu entry value used by the device
__u8 name[32] Menu entry name
* enum uvc_control_data_type
UVC_CTRL_DATA_TYPE_RAW Raw control (byte array)
UVC_CTRL_DATA_TYPE_SIGNED Signed integer
UVC_CTRL_DATA_TYPE_UNSIGNED Unsigned integer
UVC_CTRL_DATA_TYPE_BOOLEAN Boolean
UVC_CTRL_DATA_TYPE_ENUM Enumeration
UVC_CTRL_DATA_TYPE_BITMASK Bitmask
UVC_CTRL_DATA_TYPE_RECT Rectangular area}hj sbah}(h]h ]h"]h$]h&]hhƌforcelanguagenonehighlight_args}uh1j hhhKhj hhubeh}(h]3uvcioc-ctrl-map-map-a-uvc-control-to-a-v4l2-controlah ]h"]5uvcioc_ctrl_map - map a uvc control to a v4l2 controlah$]h&]uh1hhj hhhhhKnubh)}(hhh](h)}(h*UVCIOC_CTRL_QUERY - Query a UVC XU controlh]h*UVCIOC_CTRL_QUERY - Query a UVC XU control}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj hhhhhKubh)}(h%Argument: struct uvc_xu_control_queryh]h%Argument: struct uvc_xu_control_query}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj hhubh)}(h**Description**:h](j )}(h**Description**h]hDescription}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j
hj ubh:}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj hhubjB )}(hX This ioctl queries a UVC XU control identified by its extension unit ID
and control selector.
There are a number of different queries available that closely
correspond to the low-level control requests described in the UVC
specification. These requests are:
UVC_GET_CUR
Obtain the current value of the control.
UVC_GET_MIN
Obtain the minimum value of the control.
UVC_GET_MAX
Obtain the maximum value of the control.
UVC_GET_DEF
Obtain the default value of the control.
UVC_GET_RES
Query the resolution of the control, i.e. the step size of the
allowed control values.
UVC_GET_LEN
Query the size of the control in bytes.
UVC_GET_INFO
Query the control information bitmap, which indicates whether
get/set requests are supported.
UVC_SET_CUR
Update the value of the control.
Applications must set the 'size' field to the correct length for the
control. Exceptions are the UVC_GET_LEN and UVC_GET_INFO queries, for
which the size must be set to 2 and 1, respectively. The 'data' field
must point to a valid writable buffer big enough to hold the indicated
number of data bytes.
Data is copied directly from the device without any driver-side
processing. Applications are responsible for data buffer formatting,
including little-endian/big-endian conversion. This is particularly
important for the result of the UVC_GET_LEN requests, which is always
returned as a little-endian 16-bit integer by the device.
h](h)}(h]This ioctl queries a UVC XU control identified by its extension unit ID
and control selector.h]h]This ioctl queries a UVC XU control identified by its extension unit ID
and control selector.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj
ubh)}(hThere are a number of different queries available that closely
correspond to the low-level control requests described in the UVC
specification. These requests are:h]hThere are a number of different queries available that closely
correspond to the low-level control requests described in the UVC
specification. These requests are:}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj
ubj )}(hhh](j )}(h4UVC_GET_CUR
Obtain the current value of the control.h](j )}(hUVC_GET_CURh]hUVC_GET_CUR}(hj4 hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj0 ubj )}(hhh]h)}(h(Obtain the current value of the control.h]h(Obtain the current value of the control.}(hjE hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjB ubah}(h]h ]h"]h$]h&]uh1j hj0 ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubj )}(h4UVC_GET_MIN
Obtain the minimum value of the control.h](j )}(hUVC_GET_MINh]hUVC_GET_MIN}(hjc hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj_ ubj )}(hhh]h)}(h(Obtain the minimum value of the control.h]h(Obtain the minimum value of the control.}(hjt hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjq ubah}(h]h ]h"]h$]h&]uh1j hj_ ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubj )}(h4UVC_GET_MAX
Obtain the maximum value of the control.h](j )}(hUVC_GET_MAXh]hUVC_GET_MAX}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(h(Obtain the maximum value of the control.h]h(Obtain the maximum value of the control.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubj )}(h4UVC_GET_DEF
Obtain the default value of the control.h](j )}(hUVC_GET_DEFh]hUVC_GET_DEF}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(h(Obtain the default value of the control.h]h(Obtain the default value of the control.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubj )}(hbUVC_GET_RES
Query the resolution of the control, i.e. the step size of the
allowed control values.h](j )}(hUVC_GET_RESh]hUVC_GET_RES}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(hVQuery the resolution of the control, i.e. the step size of the
allowed control values.h]hVQuery the resolution of the control, i.e. the step size of the
allowed control values.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubj )}(h3UVC_GET_LEN
Query the size of the control in bytes.h](j )}(hUVC_GET_LENh]hUVC_GET_LEN}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(h'Query the size of the control in bytes.h]h'Query the size of the control in bytes.}(hj0 hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj- ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubj )}(hjUVC_GET_INFO
Query the control information bitmap, which indicates whether
get/set requests are supported.h](j )}(hUVC_GET_INFOh]hUVC_GET_INFO}(hjN hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhjJ ubj )}(hhh]h)}(h]Query the control information bitmap, which indicates whether
get/set requests are supported.h]h]Query the control information bitmap, which indicates whether
get/set requests are supported.}(hj_ hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj\ ubah}(h]h ]h"]h$]h&]uh1j hjJ ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubj )}(h-UVC_SET_CUR
Update the value of the control.
h](j )}(hUVC_SET_CURh]hUVC_SET_CUR}(hj} hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhjy ubj )}(hhh]h)}(h Update the value of the control.h]h Update the value of the control.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hjy ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj- ubeh}(h]h ]h"]h$]h&]uh1j hj
ubh)}(hX- Applications must set the 'size' field to the correct length for the
control. Exceptions are the UVC_GET_LEN and UVC_GET_INFO queries, for
which the size must be set to 2 and 1, respectively. The 'data' field
must point to a valid writable buffer big enough to hold the indicated
number of data bytes.h]hX5 Applications must set the ‘size’ field to the correct length for the
control. Exceptions are the UVC_GET_LEN and UVC_GET_INFO queries, for
which the size must be set to 2 and 1, respectively. The ‘data’ field
must point to a valid writable buffer big enough to hold the indicated
number of data bytes.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj
ubh)}(hXH Data is copied directly from the device without any driver-side
processing. Applications are responsible for data buffer formatting,
including little-endian/big-endian conversion. This is particularly
important for the result of the UVC_GET_LEN requests, which is always
returned as a little-endian 16-bit integer by the device.h]hXH Data is copied directly from the device without any driver-side
processing. Applications are responsible for data buffer formatting,
including little-endian/big-endian conversion. This is particularly
important for the result of the UVC_GET_LEN requests, which is always
returned as a little-endian 16-bit integer by the device.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj
ubeh}(h]h ]h"]h$]h&]uh1jA hhhKhj hhubh)}(h**Return value**:h](j )}(h**Return value**h]hReturn value}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j
hj ubh:}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj hhubjB )}(hX On success 0 is returned. On error -1 is returned and errno is set
appropriately.
ENOENT
The device does not support the given control or the specified
extension unit could not be found.
ENOBUFS
The specified buffer size is incorrect (too big or too small).
EINVAL
An invalid request code was passed.
EBADRQC
The given request is not supported by the given control.
EFAULT
The data pointer references an inaccessible memory area.
h](h)}(hQOn success 0 is returned. On error -1 is returned and errno is set
appropriately.h]hQOn success 0 is returned. On error -1 is returned and errno is set
appropriately.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubj )}(hhh](j )}(hhENOENT
The device does not support the given control or the specified
extension unit could not be found.h](j )}(hENOENTh]hENOENT}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(haThe device does not support the given control or the specified
extension unit could not be found.h]haThe device does not support the given control or the specified
extension unit could not be found.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hFENOBUFS
The specified buffer size is incorrect (too big or too small).h](j )}(hENOBUFSh]hENOBUFS}(hj4 hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj0 ubj )}(hhh]h)}(h>The specified buffer size is incorrect (too big or too small).h]h>The specified buffer size is incorrect (too big or too small).}(hjE hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjB ubah}(h]h ]h"]h$]h&]uh1j hj0 ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(h*EINVAL
An invalid request code was passed.h](j )}(hEINVALh]hEINVAL}(hjc hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj_ ubj )}(hhh]h)}(h#An invalid request code was passed.h]h#An invalid request code was passed.}(hjt hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhjq ubah}(h]h ]h"]h$]h&]uh1j hj_ ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(h@EBADRQC
The given request is not supported by the given control.h](j )}(hEBADRQCh]hEBADRQC}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(h8The given request is not supported by the given control.h]h8The given request is not supported by the given control.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(h@EFAULT
The data pointer references an inaccessible memory area.
h](j )}(hEFAULTh]hEFAULT}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j hhhKhj ubj )}(hhh]h)}(h8The data pointer references an inaccessible memory area.h]h8The data pointer references an inaccessible memory area.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhKhj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hhhKhj ubeh}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1jA hhhKhj hhubh)}(h**Data types**:h](j )}(h**Data types**h]h
Data types}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j
hj ubh:}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhKhj hhubj )}(hX * struct uvc_xu_control_query
__u8 unit Extension unit ID
__u8 selector Control selector
__u8 query Request code to send to the device
__u16 size Control data size (in bytes)
__u8 *data Control valueh]hX * struct uvc_xu_control_query
__u8 unit Extension unit ID
__u8 selector Control selector
__u8 query Request code to send to the device
__u16 size Control data size (in bytes)
__u8 *data Control value}hj sbah}(h]h ]h"]h$]h&]hhj j nonej }uh1j hhhKhj hhubeh}(h](uvcioc-ctrl-query-query-a-uvc-xu-controlah ]h"]*uvcioc_ctrl_query - query a uvc xu controlah$]h&]uh1hhj hhhhhKubeh}(h]ioctl-referenceah ]h"]ioctl referenceah$]h&]uh1hhj hhhhhKkubeh}(h]extension-unit-xu-supportah ]h"]extension unit (xu) supportah$]h&]uh1hhhhhhhhKubh)}(hhh](h)}(hDriver-specific V4L2 controlsh]hDriver-specific V4L2 controls}(hj? hhhNhNubah}(h]h ]h"]h$]h&]uh1hhj< hhhhhMubh)}(hCThe uvcvideo driver implements the following UVC-specific controls:h]hCThe uvcvideo driver implements the following UVC-specific controls:}(hjM hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhMhj< hhubj )}(hhh](j )}(hX ``V4L2_CID_UVC_REGION_OF_INTEREST_RECT (struct)``
This control determines the region of interest (ROI). ROI is a
rectangular area represented by a struct :c:type:`v4l2_rect`. The
rectangle is in global sensor coordinates using pixel units. It is
independent of the field of view, not impacted by any cropping or
scaling.
Use ``V4L2_CTRL_WHICH_MIN_VAL`` and ``V4L2_CTRL_WHICH_MAX_VAL`` to query
the range of rectangle sizes.
Setting a ROI allows the camera to optimize the capture for the region.
The value of ``V4L2_CID_REGION_OF_INTEREST_AUTO`` control determines
the detailed behavior.
An example of use of this control, can be found in the:
`Chrome OS USB camera HAL.
`
h](j )}(h1``V4L2_CID_UVC_REGION_OF_INTEREST_RECT (struct)``h]hliteral)}(hjd h]h-V4L2_CID_UVC_REGION_OF_INTEREST_RECT (struct)}(hjh hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hjb ubah}(h]h ]h"]h$]h&]uh1j hhhMhj^ ubj )}(hhh](h)}(hX This control determines the region of interest (ROI). ROI is a
rectangular area represented by a struct :c:type:`v4l2_rect`. The
rectangle is in global sensor coordinates using pixel units. It is
independent of the field of view, not impacted by any cropping or
scaling.h](hhThis control determines the region of interest (ROI). ROI is a
rectangular area represented by a struct }(hj~ hhhNhNubh)}(h:c:type:`v4l2_rect`h]jg )}(hj h]h v4l2_rect}(hj hhhNhNubah}(h]h ](xrefcc-typeeh"]h$]h&]uh1jf hj ubah}(h]h ]h"]h$]h&]refdoc$userspace-api/media/drivers/uvcvideo refdomainj reftypetyperefexplicitrefwarn reftarget v4l2_rectuh1hhhhMhj~ ubh. The
rectangle is in global sensor coordinates using pixel units. It is
independent of the field of view, not impacted by any cropping or
scaling.}(hj~ hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhj{ ubh)}(hfUse ``V4L2_CTRL_WHICH_MIN_VAL`` and ``V4L2_CTRL_WHICH_MAX_VAL`` to query
the range of rectangle sizes.h](hUse }(hj hhhNhNubjg )}(h``V4L2_CTRL_WHICH_MIN_VAL``h]hV4L2_CTRL_WHICH_MIN_VAL}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj ubh and }(hj hhhNhNubjg )}(h``V4L2_CTRL_WHICH_MAX_VAL``h]hV4L2_CTRL_WHICH_MAX_VAL}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj ubh' to query
the range of rectangle sizes.}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhj{ ubh)}(hSetting a ROI allows the camera to optimize the capture for the region.
The value of ``V4L2_CID_REGION_OF_INTEREST_AUTO`` control determines
the detailed behavior.h](hUSetting a ROI allows the camera to optimize the capture for the region.
The value of }(hj hhhNhNubjg )}(h$``V4L2_CID_REGION_OF_INTEREST_AUTO``h]h V4L2_CID_REGION_OF_INTEREST_AUTO}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj ubh* control determines
the detailed behavior.}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhj{ ubh)}(hAn example of use of this control, can be found in the:
`Chrome OS USB camera HAL.
`h](h8An example of use of this control, can be found in the:
}(hj hhhNhNubhtitle_reference)}(h`Chrome OS USB camera HAL.
`h]hChrome OS USB camera HAL.
}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1j
hj ubeh}(h]h ]h"]h$]h&]uh1hhhhMhj{ ubeh}(h]h ]h"]h$]h&]uh1j hj^ ubeh}(h]h ]h"]h$]h&]uh1j hhhMhj[ ubj )}(hX ``V4L2_CID_UVC_REGION_OF_INTEREST_AUTO (bitmask)``
This determines which, if any, on-board features should track to the
Region of Interest specified by the current value of
``V4L2_CID_UVD__REGION_OF_INTEREST_RECT``.
Max value is a mask indicating all supported Auto Controls.
h](j )}(h2``V4L2_CID_UVC_REGION_OF_INTEREST_AUTO (bitmask)``h]jg )}(hj5 h]h.V4L2_CID_UVC_REGION_OF_INTEREST_AUTO (bitmask)}(hj7 hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj3 ubah}(h]h ]h"]h$]h&]uh1j hhhM"hj/ ubj )}(hhh](h)}(hThis determines which, if any, on-board features should track to the
Region of Interest specified by the current value of
``V4L2_CID_UVD__REGION_OF_INTEREST_RECT``.h](hzThis determines which, if any, on-board features should track to the
Region of Interest specified by the current value of
}(hjM hhhNhNubjg )}(h)``V4L2_CID_UVD__REGION_OF_INTEREST_RECT``h]h%V4L2_CID_UVD__REGION_OF_INTEREST_RECT}(hjU hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hjM ubh.}(hjM hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhMhjJ ubh)}(h;Max value is a mask indicating all supported Auto Controls.h]h;Max value is a mask indicating all supported Auto Controls.}(hjm hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM"hjJ ubeh}(h]h ]h"]h$]h&]uh1j hj/ ubeh}(h]h ]h"]h$]h&]uh1j hhhM"hj[ hhubeh}(h]h ]h"]h$]h&]uh1j hj< hhhhhNubhtable)}(hhh]htgroup)}(hhh](hcolspec)}(hhh]h}(h]h ]h"]h$]h&]colwidthK2uh1j hj ubj )}(hhh]h}(h]h ]h"]h$]h&]colwidthK2uh1j hj ubhtbody)}(hhh](hrow)}(hhh](hentry)}(hhh]h)}(h-``V4L2_UVC_REGION_OF_INTEREST_AUTO_EXPOSURE``h]jg )}(hj h]h)V4L2_UVC_REGION_OF_INTEREST_AUTO_EXPOSURE}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj ubah}(h]h ]h"]h$]h&]uh1hhhhM(hj ubah}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh]h)}(hfSetting this bit causes automatic exposure to track the region of
interest instead of the whole image.h]hfSetting this bit causes automatic exposure to track the region of
interest instead of the whole image.}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM)hj ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh](j )}(hhh]h)}(h)``V4L2_UVC_REGION_OF_INTEREST_AUTO_IRIS``h]jg )}(hj h]h%V4L2_UVC_REGION_OF_INTEREST_AUTO_IRIS}(hj
hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj ubah}(h]h ]h"]h$]h&]uh1hhhhM+hj ubah}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh]h)}(hbSetting this bit causes automatic iris to track the region of interest
instead of the whole image.h]hbSetting this bit causes automatic iris to track the region of interest
instead of the whole image.}(hj
hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM,hj
ubah}(h]h ]h"]h$]h&]uh1j hj ubeh}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh](j )}(hhh]h)}(h2``V4L2_UVC_REGION_OF_INTEREST_AUTO_WHITE_BALANCE``h]jg )}(hj>
h]h.V4L2_UVC_REGION_OF_INTEREST_AUTO_WHITE_BALANCE}(hj@
hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj<
ubah}(h]h ]h"]h$]h&]uh1hhhhM.hj9
ubah}(h]h ]h"]h$]h&]uh1j hj6
ubj )}(hhh]h)}(hkSetting this bit causes automatic white balance to track the region
of interest instead of the whole image.h]hkSetting this bit causes automatic white balance to track the region
of interest instead of the whole image.}(hj\
hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM/hjY
ubah}(h]h ]h"]h$]h&]uh1j hj6
ubeh}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh](j )}(hhh]h)}(h*``V4L2_UVC_REGION_OF_INTEREST_AUTO_FOCUS``h]jg )}(hj~
h]h&V4L2_UVC_REGION_OF_INTEREST_AUTO_FOCUS}(hj
hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj|
ubah}(h]h ]h"]h$]h&]uh1hhhhM1hjy
ubah}(h]h ]h"]h$]h&]uh1j hjv
ubj )}(hhh]h)}(hnSetting this bit causes automatic focus adjustment to track the region
of interest instead of the whole image.h]hnSetting this bit causes automatic focus adjustment to track the region
of interest instead of the whole image.}(hj
hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM2hj
ubah}(h]h ]h"]h$]h&]uh1j hjv
ubeh}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh](j )}(hhh]h)}(h0``V4L2_UVC_REGION_OF_INTEREST_AUTO_FACE_DETECT``h]jg )}(hj
h]h,V4L2_UVC_REGION_OF_INTEREST_AUTO_FACE_DETECT}(hj
hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj
ubah}(h]h ]h"]h$]h&]uh1hhhhM4hj
ubah}(h]h ]h"]h$]h&]uh1j hj
ubj )}(hhh]h)}(hlSetting this bit causes automatic face detection to track the region of
interest instead of the whole image.h]hlSetting this bit causes automatic face detection to track the region of
interest instead of the whole image.}(hj
hhhNhNubah}(h]h ]h"]h$]h&]uh1hhhhM5hj
ubah}(h]h ]h"]h$]h&]uh1j hj
ubeh}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh](j )}(hhh]h)}(h5``V4L2_UVC_REGION_OF_INTEREST_AUTO_DETECT_AND_TRACK``h]jg )}(hj
h]h1V4L2_UVC_REGION_OF_INTEREST_AUTO_DETECT_AND_TRACK}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj
ubah}(h]h ]h"]h$]h&]uh1hhhhM7hj
ubah}(h]h ]h"]h$]h&]uh1j hj
ubj )}(hhh]h)}(hSetting this bit enables automatic face detection and tracking. The
current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
the driver.h](hUSetting this bit enables automatic face detection and tracking. The
current value of }(hj hhhNhNubjg )}(h$``V4L2_CID_REGION_OF_INTEREST_RECT``h]h V4L2_CID_REGION_OF_INTEREST_RECT}(hj$ hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj ubh may be updated by
the driver.}(hj hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhM8hj ubah}(h]h ]h"]h$]h&]uh1j hj
ubeh}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh](j )}(hhh]h)}(h8``V4L2_UVC_REGION_OF_INTEREST_AUTO_IMAGE_STABILIZATION``h]jg )}(hjP h]h4V4L2_UVC_REGION_OF_INTEREST_AUTO_IMAGE_STABILIZATION}(hjR hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hjN ubah}(h]h ]h"]h$]h&]uh1hhhhM;hjK ubah}(h]h ]h"]h$]h&]uh1j hjH ubj )}(hhh]h)}(hSetting this bit enables automatic image stabilization. The
current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
the driver.h](hMSetting this bit enables automatic image stabilization. The
current value of }(hjn hhhNhNubjg )}(h$``V4L2_CID_REGION_OF_INTEREST_RECT``h]h V4L2_CID_REGION_OF_INTEREST_RECT}(hjv hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hjn ubh may be updated by
the driver.}(hjn hhhNhNubeh}(h]h ]h"]h$]h&]uh1hhhhM<hjk ubah}(h]h ]h"]h$]h&]uh1j hjH ubeh}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh](j )}(hhh]h)}(h3``V4L2_UVC_REGION_OF_INTEREST_AUTO_HIGHER_QUALITY``h]jg )}(hj h]h/V4L2_UVC_REGION_OF_INTEREST_AUTO_HIGHER_QUALITY}(hj hhhNhNubah}(h]h ]h"]h$]h&]uh1jf hj ubah}(h]h ]h"]h$]h&]uh1hhhhM?hj ubah}(h]h ]h"]h$]h&]uh1j hj ubj )}(hhh]h)}(hdSetting this bit enables automatically capture the specified region
with higher quality if possible.h]hdSetting this bit enables automatically capture the specified region
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