1.. Permission is granted to copy, distribute and/or modify this 2.. document under the terms of the GNU Free Documentation License, 3.. Version 1.1 or any later version published by the Free Software 4.. Foundation, with no Invariant Sections, no Front-Cover Texts 5.. and no Back-Cover Texts. A copy of the license is included at 6.. Documentation/userspace-api/media/fdl-appendix.rst. 7.. 8.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections 9 10.. _VIDIOC_ENUM_DV_TIMINGS: 11 12*********************************************************** 13ioctl VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS 14*********************************************************** 15 16Name 17==== 18 19VIDIOC_ENUM_DV_TIMINGS - VIDIOC_SUBDEV_ENUM_DV_TIMINGS - Enumerate supported Digital Video timings 20 21 22Synopsis 23======== 24 25.. c:function:: int ioctl( int fd, VIDIOC_ENUM_DV_TIMINGS, struct v4l2_enum_dv_timings *argp ) 26 :name: VIDIOC_ENUM_DV_TIMINGS 27 28.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUM_DV_TIMINGS, struct v4l2_enum_dv_timings *argp ) 29 :name: VIDIOC_SUBDEV_ENUM_DV_TIMINGS 30 31 32Arguments 33========= 34 35``fd`` 36 File descriptor returned by :ref:`open() <func-open>`. 37 38``argp`` 39 Pointer to struct :c:type:`v4l2_enum_dv_timings`. 40 41 42Description 43=========== 44 45While some DV receivers or transmitters support a wide range of timings, 46others support only a limited number of timings. With this ioctl 47applications can enumerate a list of known supported timings. Call 48:ref:`VIDIOC_DV_TIMINGS_CAP` to check if it 49also supports other standards or even custom timings that are not in 50this list. 51 52To query the available timings, applications initialize the ``index`` 53field, set the ``pad`` field to 0, zero the reserved array of struct 54:c:type:`v4l2_enum_dv_timings` and call the 55``VIDIOC_ENUM_DV_TIMINGS`` ioctl on a video node with a pointer to this 56structure. Drivers fill the rest of the structure or return an ``EINVAL`` 57error code when the index is out of bounds. To enumerate all supported 58DV timings, applications shall begin at index zero, incrementing by one 59until the driver returns ``EINVAL``. 60 61.. note:: 62 63 Drivers may enumerate a different set of DV timings after 64 switching the video input or output. 65 66When implemented by the driver DV timings of subdevices can be queried 67by calling the ``VIDIOC_SUBDEV_ENUM_DV_TIMINGS`` ioctl directly on a 68subdevice node. The DV timings are specific to inputs (for DV receivers) 69or outputs (for DV transmitters), applications must specify the desired 70pad number in the struct 71:c:type:`v4l2_enum_dv_timings` ``pad`` field. 72Attempts to enumerate timings on a pad that doesn't support them will 73return an ``EINVAL`` error code. 74 75 76.. c:type:: v4l2_enum_dv_timings 77 78.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| 79 80.. flat-table:: struct v4l2_enum_dv_timings 81 :header-rows: 0 82 :stub-columns: 0 83 :widths: 1 1 2 84 85 * - __u32 86 - ``index`` 87 - Number of the DV timings, set by the application. 88 * - __u32 89 - ``pad`` 90 - Pad number as reported by the media controller API. This field is 91 only used when operating on a subdevice node. When operating on a 92 video node applications must set this field to zero. 93 * - __u32 94 - ``reserved``\ [2] 95 - Reserved for future extensions. Drivers and applications must set 96 the array to zero. 97 * - struct :c:type:`v4l2_dv_timings` 98 - ``timings`` 99 - The timings. 100 101 102Return Value 103============ 104 105On success 0 is returned, on error -1 and the ``errno`` variable is set 106appropriately. The generic error codes are described at the 107:ref:`Generic Error Codes <gen-errors>` chapter. 108 109EINVAL 110 The struct :c:type:`v4l2_enum_dv_timings` 111 ``index`` is out of bounds or the ``pad`` number is invalid. 112 113ENODATA 114 Digital video presets are not supported for this input or output. 115