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+.. -*- coding: utf-8; mode: rst -*-
+
+.. _VIDIOC_ENUM_FMT:
+
+*********************
+ioctl VIDIOC_ENUM_FMT
+*********************
+
+Name
+====
+
+VIDIOC_ENUM_FMT - Enumerate image formats
+
+
+Synopsis
+========
+
+.. cpp:function:: int ioctl( int fd, int request, struct v4l2_fmtdesc *argp )
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :ref:`open() <func-open>`.
+
+``request``
+    VIDIOC_ENUM_FMT
+
+``argp``
+
+
+Description
+===========
+
+To enumerate image formats applications initialize the ``type`` and
+``index`` field of struct :ref:`v4l2_fmtdesc <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.
+
+
+.. _v4l2-fmtdesc:
+
+.. flat-table:: struct v4l2_fmtdesc
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+
+    -  .. row 1
+
+       -  __u32
+
+       -  ``index``
+
+       -  Number of the format in the enumeration, set by the application.
+	  This is in no way related to the ``pixelformat`` field.
+
+    -  .. row 2
+
+       -  __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`` and
+	  ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. See :ref:`v4l2-buf-type`.
+
+    -  .. row 3
+
+       -  __u32
+
+       -  ``flags``
+
+       -  See :ref:`fmtdesc-flags`
+
+    -  .. row 4
+
+       -  __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".
+
+    -  .. row 5
+
+       -  __u32
+
+       -  ``pixelformat``
+
+       -  The image format identifier. This is a four character code as
+	  computed by the v4l2_fourcc() macro:
+
+    -  .. row 6
+
+       -  :cspan:`2`
+
+
+	  .. _v4l2-fourcc:
+	  .. code-block:: c
+
+	      #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.
+
+    -  .. row 7
+
+       -  __u32
+
+       -  ``reserved``\ [4]
+
+       -  Reserved for future extensions. Drivers must set the array to
+	  zero.
+
+
+
+.. _fmtdesc-flags:
+
+.. flat-table:: Image Format Description Flags
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       3 1 4
+
+
+    -  .. row 1
+
+       -  ``V4L2_FMT_FLAG_COMPRESSED``
+
+       -  0x0001
+
+       -  This is a compressed format.
+
+    -  .. row 2
+
+       -  ``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.
+
+
+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 :ref:`v4l2_fmtdesc <v4l2-fmtdesc>` ``type`` is not
+    supported or the ``index`` is out of bounds.