diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-enum-fmt.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-enum-fmt.rst | 157 |
1 files changed, 0 insertions, 157 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst deleted file mode 100644 index 399ef1062bac..000000000000 --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst +++ /dev/null @@ -1,157 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. _VIDIOC_ENUM_FMT: - -********************* -ioctl VIDIOC_ENUM_FMT -********************* - -Name -==== - -VIDIOC_ENUM_FMT - Enumerate image formats - - -Synopsis -======== - -.. c:function:: int ioctl( int fd, VIDIOC_ENUM_FMT, struct v4l2_fmtdesc *argp ) - :name: VIDIOC_ENUM_FMT - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <func-open>`. - -``argp`` - Pointer to struct :c:type:`v4l2_fmtdesc`. - - -Description -=========== - -To enumerate image formats applications initialize the ``type`` and -``index`` field of struct :c:type:`v4l2_fmtdesc` and call -the :ref:`VIDIOC_ENUM_FMT` ioctl with a pointer to this structure. Drivers -fill the rest of the structure or return an ``EINVAL`` error code. All -formats are enumerable by beginning at index zero and incrementing by -one until ``EINVAL`` is returned. - -.. note:: - - After switching input or output the list of enumerated image - formats may be different. - - -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| - -.. c:type:: v4l2_fmtdesc - -.. flat-table:: struct v4l2_fmtdesc - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``index`` - - Number of the format in the enumeration, set by the application. - This is in no way related to the ``pixelformat`` field. - * - __u32 - - ``type`` - - Type of the data stream, set by the application. Only these types - are valid here: ``V4L2_BUF_TYPE_VIDEO_CAPTURE``, - ``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE``, - ``V4L2_BUF_TYPE_VIDEO_OUTPUT``, - ``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``, - ``V4L2_BUF_TYPE_VIDEO_OVERLAY``, - ``V4L2_BUF_TYPE_SDR_CAPTURE``, - ``V4L2_BUF_TYPE_SDR_OUTPUT`` and - ``V4L2_BUF_TYPE_META_CAPTURE``. - See :c:type:`v4l2_buf_type`. - * - __u32 - - ``flags`` - - See :ref:`fmtdesc-flags` - * - __u8 - - ``description``\ [32] - - Description of the format, a NUL-terminated ASCII string. This - information is intended for the user, for example: "YUV 4:2:2". - * - __u32 - - ``pixelformat`` - - The image format identifier. This is a four character code as - computed by the v4l2_fourcc() macro: - * - :cspan:`2` - - .. _v4l2-fourcc: - - ``#define v4l2_fourcc(a,b,c,d)`` - - ``(((__u32)(a)<<0)|((__u32)(b)<<8)|((__u32)(c)<<16)|((__u32)(d)<<24))`` - - Several image formats are already defined by this specification in - :ref:`pixfmt`. - - .. attention:: - - These codes are not the same as those used - in the Windows world. - * - __u32 - - ``reserved``\ [4] - - Reserved for future extensions. Drivers must set the array to - zero. - - - -.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| - -.. _fmtdesc-flags: - -.. flat-table:: Image Format Description Flags - :header-rows: 0 - :stub-columns: 0 - :widths: 3 1 4 - - * - ``V4L2_FMT_FLAG_COMPRESSED`` - - 0x0001 - - This is a compressed format. - * - ``V4L2_FMT_FLAG_EMULATED`` - - 0x0002 - - This format is not native to the device but emulated through - software (usually libv4l2), where possible try to use a native - format instead for better performance. - * - ``V4L2_FMT_FLAG_CONTINUOUS_BYTESTREAM`` - - 0x0004 - - The hardware decoder for this compressed bytestream format (aka coded - format) is capable of parsing a continuous bytestream. Applications do - not need to parse the bytestream themselves to find the boundaries - between frames/fields. This flag can only be used in combination with - the ``V4L2_FMT_FLAG_COMPRESSED`` flag, since this applies to compressed - formats only. This flag is valid for stateful decoders only. - * - ``V4L2_FMT_FLAG_DYN_RESOLUTION`` - - 0x0008 - - Dynamic resolution switching is supported by the device for this - compressed bytestream format (aka coded format). It will notify the user - via the event ``V4L2_EVENT_SOURCE_CHANGE`` when changes in the video - parameters are detected. This flag can only be used in combination - with the ``V4L2_FMT_FLAG_COMPRESSED`` flag, since this applies to - compressed formats only. It is also only applies to stateful codecs. - - -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. - -EINVAL - The struct :c:type:`v4l2_fmtdesc` ``type`` is not - supported or the ``index`` is out of bounds. |