.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later .. c:namespace:: V4L

.. _func-munmap:

V4L2 munmap()

Name

v4l2-munmap - Unmap device memory

Synopsis

.. code-block:: c

#include <unistd.h>
#include <sys/mman.h>

.. c:function:: int munmap( void *start, size_t length )

Arguments

start Address of the mapped buffer as returned by the :c:func:mmap() function.

length Length of the mapped buffer. This must be the same value as given to :c:func:mmap() and returned by the driver in the struct :c:type:v4l2_buffer length field for the single-planar API and in the struct :c:type:v4l2_plane length field for the multi-planar API.

Description

Unmaps a previously with the :c:func:mmap() function mapped buffer and frees it, if possible.

Return Value

On success :c:func:munmap() returns 0, on failure -1 and the errno variable is set appropriately:

EINVAL The start or length is incorrect, or no buffers have been mapped yet.