Synopsis
========
-.. cpp:function:: int ioctl( int fd, int request, struct v4l2_requestbuffers *argp )
+.. c:function:: int ioctl( int fd, VIDIOC_REQBUFS, struct v4l2_requestbuffers *argp )
+ :name: VIDIOC_REQBUFS
Arguments
``fd``
File descriptor returned by :ref:`open() <func-open>`.
-``request``
- VIDIOC_REQBUFS
-
``argp``
allocation.
To allocate device buffers applications initialize all fields of the
-:ref:`struct v4l2_requestbuffers <v4l2-requestbuffers>` structure. They set the ``type``
+struct :c:type:`v4l2_requestbuffers` structure. They set the ``type``
field to the respective stream or buffer type, the ``count`` field to
the desired number of buffers, ``memory`` must be set to the requested
I/O method and the ``reserved`` array must be zeroed. When the ioctl is
:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>`.
-.. _v4l2-requestbuffers:
+.. c:type:: v4l2_requestbuffers
+
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
.. flat-table:: struct v4l2_requestbuffers
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2
-
- - .. row 1
-
- - __u32
-
- - ``count``
-
- - The number of buffers requested or granted.
-
- - .. row 2
-
- - __u32
-
- - ``type``
-
- - Type of the stream or buffers, this is the same as the struct
- :ref:`v4l2_format <v4l2-format>` ``type`` field. See
- :ref:`v4l2-buf-type` for valid values.
-
- - .. row 3
-
- - __u32
-
- - ``memory``
-
- - Applications set this field to ``V4L2_MEMORY_MMAP``,
- ``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See
- :ref:`v4l2-memory`.
-
- - .. row 4
-
- - __u32
-
- - ``reserved``\ [2]
-
- - A place holder for future extensions. Drivers and applications
- must set the array to zero.
+ * - __u32
+ - ``count``
+ - The number of buffers requested or granted.
+ * - __u32
+ - ``type``
+ - Type of the stream or buffers, this is the same as the struct
+ :c:type:`v4l2_format` ``type`` field. See
+ :c:type:`v4l2_buf_type` for valid values.
+ * - __u32
+ - ``memory``
+ - Applications set this field to ``V4L2_MEMORY_MMAP``,
+ ``V4L2_MEMORY_DMABUF`` or ``V4L2_MEMORY_USERPTR``. See
+ :c:type:`v4l2_memory`.
+ * - __u32
+ - ``reserved``\ [2]
+ - A place holder for future extensions. Drivers and applications
+ must set the array to zero.
Return Value