.. -*- coding: utf-8; mode: rst -*- .. _VIDIOC_ENUM_DV_TIMINGS: *********************************************************** ioctl VIDIOC_ENUM_DV_TIMINGS, VIDIOC_SUBDEV_ENUM_DV_TIMINGS *********************************************************** Name ==== VIDIOC_ENUM_DV_TIMINGS - VIDIOC_SUBDEV_ENUM_DV_TIMINGS - Enumerate supported Digital Video timings Synopsis ======== .. c:function:: int ioctl( int fd, VIDIOC_ENUM_DV_TIMINGS, struct v4l2_enum_dv_timings *argp ) :name: VIDIOC_ENUM_DV_TIMINGS .. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUM_DV_TIMINGS, struct v4l2_enum_dv_timings *argp ) :name: VIDIOC_SUBDEV_ENUM_DV_TIMINGS Arguments ========= ``fd`` File descriptor returned by :ref:`open() `. ``argp`` Description =========== While some DV receivers or transmitters support a wide range of timings, others support only a limited number of timings. With this ioctl applications can enumerate a list of known supported timings. Call :ref:`VIDIOC_DV_TIMINGS_CAP` to check if it also supports other standards or even custom timings that are not in this list. To query the available timings, applications initialize the ``index`` field, set the ``pad`` field to 0, zero the reserved array of struct :c:type:`v4l2_enum_dv_timings` and call the ``VIDIOC_ENUM_DV_TIMINGS`` ioctl on a video node 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 supported DV timings, applications shall begin at index zero, incrementing by one until the driver returns ``EINVAL``. .. note:: Drivers may enumerate a different set of DV timings after switching the video input or output. When implemented by the driver DV timings of subdevices can be queried by calling the ``VIDIOC_SUBDEV_ENUM_DV_TIMINGS`` ioctl directly on a subdevice node. The DV timings 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_enum_dv_timings` ``pad`` field. Attempts to enumerate timings on a pad that doesn't support them will return an ``EINVAL`` error code. .. c:type:: v4l2_enum_dv_timings .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| .. flat-table:: struct v4l2_enum_dv_timings :header-rows: 0 :stub-columns: 0 :widths: 1 1 2 - .. row 1 - __u32 - ``index`` - Number of the DV timings, set by the application. - .. row 2 - __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. - .. row 3 - __u32 - ``reserved``\ [2] - Reserved for future extensions. Drivers and applications must set the array to zero. - .. row 4 - struct :c:type:`v4l2_dv_timings` - ``timings`` - The timings. 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 ` chapter. EINVAL The struct :c:type:`v4l2_enum_dv_timings` ``index`` is out of bounds or the ``pad`` number is invalid. ENODATA Digital video presets are not supported for this input or output.