1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2.. c:namespace:: V4L 3 4.. _VIDIOC_ENUM_DV_TIMINGS: 5 6*********************************************************** 7ioctl VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS 8*********************************************************** 9 10Name 11==== 12 13VIDIOC_ENUM_DV_TIMINGS - VIDIOC_SUBDEV_ENUM_DV_TIMINGS - Enumerate supported Digital Video timings 14 15Synopsis 16======== 17 18.. c:macro:: VIDIOC_ENUM_DV_TIMINGS 19 20``int ioctl(int fd, VIDIOC_ENUM_DV_TIMINGS, struct v4l2_enum_dv_timings *argp)`` 21 22.. c:macro:: VIDIOC_SUBDEV_ENUM_DV_TIMINGS 23 24``int ioctl(int fd, VIDIOC_SUBDEV_ENUM_DV_TIMINGS, struct v4l2_enum_dv_timings *argp)`` 25 26Arguments 27========= 28 29``fd`` 30 File descriptor returned by :c:func:`open()`. 31 32``argp`` 33 Pointer to struct :c:type:`v4l2_enum_dv_timings`. 34 35Description 36=========== 37 38While some DV receivers or transmitters support a wide range of timings, 39others support only a limited number of timings. With this ioctl 40applications can enumerate a list of known supported timings. Call 41:ref:`VIDIOC_DV_TIMINGS_CAP` to check if it 42also supports other standards or even custom timings that are not in 43this list. 44 45To query the available timings, applications initialize the ``index`` 46field, set the ``pad`` field to 0, zero the reserved array of struct 47:c:type:`v4l2_enum_dv_timings` and call the 48``VIDIOC_ENUM_DV_TIMINGS`` ioctl on a video node with a pointer to this 49structure. Drivers fill the rest of the structure or return an ``EINVAL`` 50error code when the index is out of bounds. To enumerate all supported 51DV timings, applications shall begin at index zero, incrementing by one 52until the driver returns ``EINVAL``. 53 54.. note:: 55 56 Drivers may enumerate a different set of DV timings after 57 switching the video input or output. 58 59When implemented by the driver DV timings of subdevices can be queried 60by calling the ``VIDIOC_SUBDEV_ENUM_DV_TIMINGS`` ioctl directly on a 61subdevice node. The DV timings are specific to inputs (for DV receivers) 62or outputs (for DV transmitters), applications must specify the desired 63pad number in the struct 64:c:type:`v4l2_enum_dv_timings` ``pad`` field. 65Attempts to enumerate timings on a pad that doesn't support them will 66return an ``EINVAL`` error code. 67 68.. c:type:: v4l2_enum_dv_timings 69 70.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| 71 72.. flat-table:: struct v4l2_enum_dv_timings 73 :header-rows: 0 74 :stub-columns: 0 75 :widths: 1 1 2 76 77 * - __u32 78 - ``index`` 79 - Number of the DV timings, set by the application. 80 * - __u32 81 - ``pad`` 82 - Pad number as reported by the media controller API. This field is 83 only used when operating on a subdevice node. When operating on a 84 video node applications must set this field to zero. 85 * - __u32 86 - ``reserved``\ [2] 87 - Reserved for future extensions. Drivers and applications must set 88 the array to zero. 89 * - struct :c:type:`v4l2_dv_timings` 90 - ``timings`` 91 - The timings. 92 93Return Value 94============ 95 96On success 0 is returned, on error -1 and the ``errno`` variable is set 97appropriately. The generic error codes are described at the 98:ref:`Generic Error Codes <gen-errors>` chapter. 99 100EINVAL 101 The struct :c:type:`v4l2_enum_dv_timings` 102 ``index`` is out of bounds or the ``pad`` number is invalid. 103 104ENODATA 105 Digital video presets are not supported for this input or output. 106