diff options
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-dv-timings-cap.rst')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-dv-timings-cap.rst | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-dv-timings-cap.rst b/Documentation/userspace-api/media/v4l/vidioc-dv-timings-cap.rst new file mode 100644 index 000000000..8ced100bb --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-dv-timings-cap.rst @@ -0,0 +1,159 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_DV_TIMINGS_CAP: + +********************************************************* +ioctl VIDIOC_DV_TIMINGS_CAP, VIDIOC_SUBDEV_DV_TIMINGS_CAP +********************************************************* + +Name +==== + +VIDIOC_DV_TIMINGS_CAP - VIDIOC_SUBDEV_DV_TIMINGS_CAP - The capabilities of the Digital Video receiver/transmitter + +Synopsis +======== + +.. c:macro:: VIDIOC_DV_TIMINGS_CAP + +``int ioctl(int fd, VIDIOC_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp)`` + +.. c:macro:: VIDIOC_SUBDEV_DV_TIMINGS_CAP + +``int ioctl(int fd, VIDIOC_SUBDEV_DV_TIMINGS_CAP, struct v4l2_dv_timings_cap *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`v4l2_dv_timings_cap`. + +Description +=========== + +To query the capabilities of the DV receiver/transmitter applications +initialize the ``pad`` field to 0, zero the reserved array of struct +:c:type:`v4l2_dv_timings_cap` and call the +``VIDIOC_DV_TIMINGS_CAP`` ioctl on a video node and the driver will fill +in the structure. + +.. note:: + + Drivers may return different values after + switching the video input or output. + +When implemented by the driver DV capabilities of subdevices can be +queried by calling the ``VIDIOC_SUBDEV_DV_TIMINGS_CAP`` ioctl directly +on a subdevice node. The capabilities are specific to inputs (for DV +receivers) or outputs (for DV transmitters), applications must specify +the desired pad number in the struct +:c:type:`v4l2_dv_timings_cap` ``pad`` field and +zero the ``reserved`` array. Attempts to query capabilities on a pad +that doesn't support them will return an ``EINVAL`` error code. + +.. tabularcolumns:: |p{1.2cm}|p{3.2cm}|p{12.9cm}| + +.. c:type:: v4l2_bt_timings_cap + +.. flat-table:: struct v4l2_bt_timings_cap + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``min_width`` + - Minimum width of the active video in pixels. + * - __u32 + - ``max_width`` + - Maximum width of the active video in pixels. + * - __u32 + - ``min_height`` + - Minimum height of the active video in lines. + * - __u32 + - ``max_height`` + - Maximum height of the active video in lines. + * - __u64 + - ``min_pixelclock`` + - Minimum pixelclock frequency in Hz. + * - __u64 + - ``max_pixelclock`` + - Maximum pixelclock frequency in Hz. + * - __u32 + - ``standards`` + - The video standard(s) supported by the hardware. See + :ref:`dv-bt-standards` for a list of standards. + * - __u32 + - ``capabilities`` + - Several flags giving more information about the capabilities. See + :ref:`dv-bt-cap-capabilities` for a description of the flags. + * - __u32 + - ``reserved``\ [16] + - Reserved for future extensions. + Drivers must set the array to zero. + + +.. tabularcolumns:: |p{4.4cm}|p{3.6cm}|p{9.3cm}| + +.. c:type:: v4l2_dv_timings_cap + +.. flat-table:: struct v4l2_dv_timings_cap + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``type`` + - Type of DV timings as listed in :ref:`dv-timing-types`. + * - __u32 + - ``pad`` + - Pad number as reported by the media controller API. This field is + only used when operating on a subdevice node. When operating on a + video node applications must set this field to zero. + * - __u32 + - ``reserved``\ [2] + - Reserved for future extensions. + + Drivers and applications must set the array to zero. + * - union { + - (anonymous) + * - struct :c:type:`v4l2_bt_timings_cap` + - ``bt`` + - BT.656/1120 timings capabilities of the hardware. + * - __u32 + - ``raw_data``\ [32] + * - } + - + +.. tabularcolumns:: |p{7.2cm}|p{10.3cm}| + +.. _dv-bt-cap-capabilities: + +.. flat-table:: DV BT Timing capabilities + :header-rows: 0 + :stub-columns: 0 + + * - Flag + - Description + * - + - + * - ``V4L2_DV_BT_CAP_INTERLACED`` + - Interlaced formats are supported. + * - ``V4L2_DV_BT_CAP_PROGRESSIVE`` + - Progressive formats are supported. + * - ``V4L2_DV_BT_CAP_REDUCED_BLANKING`` + - CVT/GTF specific: the timings can make use of reduced blanking + (CVT) or the 'Secondary GTF' curve (GTF). + * - ``V4L2_DV_BT_CAP_CUSTOM`` + - Can support non-standard timings, i.e. timings not belonging to + the standards set in the ``standards`` field. + +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. |