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diff --git a/Documentation/userspace-api/media/v4l/vidioc-enuminput.rst b/Documentation/userspace-api/media/v4l/vidioc-enuminput.rst new file mode 100644 index 0000000000..d5f0535bd8 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-enuminput.rst @@ -0,0 +1,229 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_ENUMINPUT: + +********************** +ioctl VIDIOC_ENUMINPUT +********************** + +Name +==== + +VIDIOC_ENUMINPUT - Enumerate video inputs + +Synopsis +======== + +.. c:macro:: VIDIOC_ENUMINPUT + +``int ioctl(int fd, VIDIOC_ENUMINPUT, struct v4l2_input *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`v4l2_input`. + +Description +=========== + +To query the attributes of a video input applications initialize the +``index`` field of struct :c:type:`v4l2_input` and call the +:ref:`VIDIOC_ENUMINPUT` with a pointer to this structure. Drivers +fill the rest of the structure or return an ``EINVAL`` error code when the +index is out of bounds. To enumerate all inputs applications shall begin +at index zero, incrementing by one until the driver returns ``EINVAL``. + +.. tabularcolumns:: |p{3.0cm}|p{3.5cm}|p{10.8cm}| + +.. c:type:: v4l2_input + +.. flat-table:: struct v4l2_input + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``index`` + - Identifies the input, set by the application. + * - __u8 + - ``name``\ [32] + - Name of the video input, a NUL-terminated ASCII string, for + example: "Vin (Composite 2)". This information is intended for the + user, preferably the connector label on the device itself. + * - __u32 + - ``type`` + - Type of the input, see :ref:`input-type`. + * - __u32 + - ``audioset`` + - Drivers can enumerate up to 32 video and audio inputs. This field + shows which audio inputs were selectable as audio source if this + was the currently selected video input. It is a bit mask. The LSB + corresponds to audio input 0, the MSB to input 31. Any number of + bits can be set, or none. + + When the driver does not enumerate audio inputs no bits must be + set. Applications shall not interpret this as lack of audio + support. Some drivers automatically select audio sources and do + not enumerate them since there is no choice anyway. + + For details on audio inputs and how to select the current input + see :ref:`audio`. + * - __u32 + - ``tuner`` + - Capture devices can have zero or more tuners (RF demodulators). + When the ``type`` is set to ``V4L2_INPUT_TYPE_TUNER`` this is an + RF connector and this field identifies the tuner. It corresponds + to struct :c:type:`v4l2_tuner` field ``index``. For + details on tuners see :ref:`tuner`. + * - :ref:`v4l2_std_id <v4l2-std-id>` + - ``std`` + - Every video input supports one or more different video standards. + This field is a set of all supported standards. For details on + video standards and how to switch see :ref:`standard`. + * - __u32 + - ``status`` + - This field provides status information about the input. See + :ref:`input-status` for flags. With the exception of the sensor + orientation bits ``status`` is only valid when this is the current + input. + * - __u32 + - ``capabilities`` + - This field provides capabilities for the input. See + :ref:`input-capabilities` for flags. + * - __u32 + - ``reserved``\ [3] + - Reserved for future extensions. Drivers must set the array to + zero. + + +.. tabularcolumns:: |p{6.6cm}|p{1.0cm}|p{9.7cm}| + +.. _input-type: + +.. flat-table:: Input Types + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * - ``V4L2_INPUT_TYPE_TUNER`` + - 1 + - This input uses a tuner (RF demodulator). + * - ``V4L2_INPUT_TYPE_CAMERA`` + - 2 + - Any non-tuner video input, for example Composite Video, + S-Video, HDMI, camera sensor. The naming as ``_TYPE_CAMERA`` is historical, + today we would have called it ``_TYPE_VIDEO``. + * - ``V4L2_INPUT_TYPE_TOUCH`` + - 3 + - This input is a touch device for capturing raw touch data. + + +.. tabularcolumns:: |p{5.6cm}|p{2.6cm}|p{9.1cm}| + +.. _input-status: + +.. flat-table:: Input Status Flags + :header-rows: 0 + :stub-columns: 0 + + * - :cspan:`2` General + * - ``V4L2_IN_ST_NO_POWER`` + - 0x00000001 + - Attached device is off. + * - ``V4L2_IN_ST_NO_SIGNAL`` + - 0x00000002 + - + * - ``V4L2_IN_ST_NO_COLOR`` + - 0x00000004 + - The hardware supports color decoding, but does not detect color + modulation in the signal. + * - :cspan:`2` Sensor Orientation + * - ``V4L2_IN_ST_HFLIP`` + - 0x00000010 + - The input is connected to a device that produces a signal that is + flipped horizontally and does not correct this before passing the + signal to userspace. + * - ``V4L2_IN_ST_VFLIP`` + - 0x00000020 + - The input is connected to a device that produces a signal that is + flipped vertically and does not correct this before passing the + signal to userspace. + .. note:: A 180 degree rotation is the same as HFLIP | VFLIP + * - :cspan:`2` Analog Video + * - ``V4L2_IN_ST_NO_H_LOCK`` + - 0x00000100 + - No horizontal sync lock. + * - ``V4L2_IN_ST_COLOR_KILL`` + - 0x00000200 + - A color killer circuit automatically disables color decoding when + it detects no color modulation. When this flag is set the color + killer is enabled *and* has shut off color decoding. + * - ``V4L2_IN_ST_NO_V_LOCK`` + - 0x00000400 + - No vertical sync lock. + * - ``V4L2_IN_ST_NO_STD_LOCK`` + - 0x00000800 + - No standard format lock in case of auto-detection format + by the component. + * - :cspan:`2` Digital Video + * - ``V4L2_IN_ST_NO_SYNC`` + - 0x00010000 + - No synchronization lock. + * - ``V4L2_IN_ST_NO_EQU`` + - 0x00020000 + - No equalizer lock. + * - ``V4L2_IN_ST_NO_CARRIER`` + - 0x00040000 + - Carrier recovery failed. + * - :cspan:`2` VCR and Set-Top Box + * - ``V4L2_IN_ST_MACROVISION`` + - 0x01000000 + - Macrovision is an analog copy prevention system mangling the video + signal to confuse video recorders. When this flag is set + Macrovision has been detected. + * - ``V4L2_IN_ST_NO_ACCESS`` + - 0x02000000 + - Conditional access denied. + * - ``V4L2_IN_ST_VTR`` + - 0x04000000 + - VTR time constant. [?] + + +.. tabularcolumns:: |p{6.6cm}|p{2.4cm}|p{8.3cm}| + +.. _input-capabilities: + +.. flat-table:: Input capabilities + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * - ``V4L2_IN_CAP_DV_TIMINGS`` + - 0x00000002 + - This input supports setting video timings by using + ``VIDIOC_S_DV_TIMINGS``. + * - ``V4L2_IN_CAP_STD`` + - 0x00000004 + - This input supports setting the TV standard by using + ``VIDIOC_S_STD``. + * - ``V4L2_IN_CAP_NATIVE_SIZE`` + - 0x00000008 + - This input supports setting the native size using the + ``V4L2_SEL_TGT_NATIVE_SIZE`` selection target, see + :ref:`v4l2-selections-common`. + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EINVAL + The struct :c:type:`v4l2_input` ``index`` is out of + bounds. |