18c2ecf20Sopenharmony_ci.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 28c2ecf20Sopenharmony_ci.. c:namespace:: V4L 38c2ecf20Sopenharmony_ci 48c2ecf20Sopenharmony_ci.. _VIDIOC_G_STD: 58c2ecf20Sopenharmony_ci 68c2ecf20Sopenharmony_ci************************************************************************** 78c2ecf20Sopenharmony_ciioctl VIDIOC_G_STD, VIDIOC_S_STD, VIDIOC_SUBDEV_G_STD, VIDIOC_SUBDEV_S_STD 88c2ecf20Sopenharmony_ci************************************************************************** 98c2ecf20Sopenharmony_ci 108c2ecf20Sopenharmony_ciName 118c2ecf20Sopenharmony_ci==== 128c2ecf20Sopenharmony_ci 138c2ecf20Sopenharmony_ciVIDIOC_G_STD - VIDIOC_S_STD - VIDIOC_SUBDEV_G_STD - VIDIOC_SUBDEV_S_STD - Query or select the video standard of the current input 148c2ecf20Sopenharmony_ci 158c2ecf20Sopenharmony_ciSynopsis 168c2ecf20Sopenharmony_ci======== 178c2ecf20Sopenharmony_ci 188c2ecf20Sopenharmony_ci.. c:macro:: VIDIOC_G_STD 198c2ecf20Sopenharmony_ci 208c2ecf20Sopenharmony_ci``int ioctl(int fd, VIDIOC_G_STD, v4l2_std_id *argp)`` 218c2ecf20Sopenharmony_ci 228c2ecf20Sopenharmony_ci.. c:macro:: VIDIOC_S_STD 238c2ecf20Sopenharmony_ci 248c2ecf20Sopenharmony_ci``int ioctl(int fd, VIDIOC_S_STD, const v4l2_std_id *argp)`` 258c2ecf20Sopenharmony_ci 268c2ecf20Sopenharmony_ci.. c:macro:: VIDIOC_SUBDEV_G_STD 278c2ecf20Sopenharmony_ci 288c2ecf20Sopenharmony_ci``int ioctl(int fd, VIDIOC_SUBDEV_G_STD, v4l2_std_id *argp)`` 298c2ecf20Sopenharmony_ci 308c2ecf20Sopenharmony_ci.. c:macro:: VIDIOC_SUBDEV_S_STD 318c2ecf20Sopenharmony_ci 328c2ecf20Sopenharmony_ci``int ioctl(int fd, VIDIOC_SUBDEV_S_STD, const v4l2_std_id *argp)`` 338c2ecf20Sopenharmony_ci 348c2ecf20Sopenharmony_ciArguments 358c2ecf20Sopenharmony_ci========= 368c2ecf20Sopenharmony_ci 378c2ecf20Sopenharmony_ci``fd`` 388c2ecf20Sopenharmony_ci File descriptor returned by :c:func:`open()`. 398c2ecf20Sopenharmony_ci 408c2ecf20Sopenharmony_ci``argp`` 418c2ecf20Sopenharmony_ci Pointer to :c:type:`v4l2_std_id`. 428c2ecf20Sopenharmony_ci 438c2ecf20Sopenharmony_ciDescription 448c2ecf20Sopenharmony_ci=========== 458c2ecf20Sopenharmony_ci 468c2ecf20Sopenharmony_ciTo query and select the current video standard applications use the 478c2ecf20Sopenharmony_ci:ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` ioctls which take a pointer to a 488c2ecf20Sopenharmony_ci:ref:`v4l2_std_id <v4l2-std-id>` type as argument. :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` 498c2ecf20Sopenharmony_cican return a single flag or a set of flags as in struct 508c2ecf20Sopenharmony_ci:c:type:`v4l2_standard` field ``id``. The flags must be 518c2ecf20Sopenharmony_ciunambiguous such that they appear in only one enumerated 528c2ecf20Sopenharmony_cistruct :c:type:`v4l2_standard` structure. 538c2ecf20Sopenharmony_ci 548c2ecf20Sopenharmony_ci:ref:`VIDIOC_S_STD <VIDIOC_G_STD>` accepts one or more flags, being a write-only ioctl it 558c2ecf20Sopenharmony_cidoes not return the actual new standard as :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` does. When 568c2ecf20Sopenharmony_cino flags are given or the current input does not support the requested 578c2ecf20Sopenharmony_cistandard the driver returns an ``EINVAL`` error code. When the standard set 588c2ecf20Sopenharmony_ciis ambiguous drivers may return ``EINVAL`` or choose any of the requested 598c2ecf20Sopenharmony_cistandards. If the current input or output does not support standard 608c2ecf20Sopenharmony_civideo timings (e.g. if :ref:`VIDIOC_ENUMINPUT` 618c2ecf20Sopenharmony_cidoes not set the ``V4L2_IN_CAP_STD`` flag), then ``ENODATA`` error code is 628c2ecf20Sopenharmony_cireturned. 638c2ecf20Sopenharmony_ci 648c2ecf20Sopenharmony_ciCalling ``VIDIOC_SUBDEV_S_STD`` on a subdev device node that has been registered 658c2ecf20Sopenharmony_ciin read-only mode is not allowed. An error is returned and the errno variable is 668c2ecf20Sopenharmony_ciset to ``-EPERM``. 678c2ecf20Sopenharmony_ci 688c2ecf20Sopenharmony_ciReturn Value 698c2ecf20Sopenharmony_ci============ 708c2ecf20Sopenharmony_ci 718c2ecf20Sopenharmony_ciOn success 0 is returned, on error -1 and the ``errno`` variable is set 728c2ecf20Sopenharmony_ciappropriately. The generic error codes are described at the 738c2ecf20Sopenharmony_ci:ref:`Generic Error Codes <gen-errors>` chapter. 748c2ecf20Sopenharmony_ci 758c2ecf20Sopenharmony_ciEINVAL 768c2ecf20Sopenharmony_ci The :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` parameter was unsuitable. 778c2ecf20Sopenharmony_ci 788c2ecf20Sopenharmony_ciENODATA 798c2ecf20Sopenharmony_ci Standard video timings are not supported for this input or output. 808c2ecf20Sopenharmony_ci 818c2ecf20Sopenharmony_ciEPERM 828c2ecf20Sopenharmony_ci ``VIDIOC_SUBDEV_S_STD`` has been called on a read-only subdevice. 83