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1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later2.. c:namespace:: V4L3 4.. _VIDIOC_ENUMAUDIO:5 6**********************7ioctl VIDIOC_ENUMAUDIO8**********************9 10Name11====12 13VIDIOC_ENUMAUDIO - Enumerate audio inputs14 15Synopsis16========17 18.. c:macro:: VIDIOC_ENUMAUDIO19 20``int ioctl(int fd, VIDIOC_ENUMAUDIO, struct v4l2_audio *argp)``21 22Arguments23=========24 25``fd``26 File descriptor returned by :c:func:`open()`.27 28``argp``29 Pointer to struct :c:type:`v4l2_audio`.30 31Description32===========33 34To query the attributes of an audio input applications initialize the35``index`` field and zero out the ``reserved`` array of a struct36:c:type:`v4l2_audio` and call the :ref:`VIDIOC_ENUMAUDIO`37ioctl with a pointer to this structure. Drivers fill the rest of the38structure or return an ``EINVAL`` error code when the index is out of39bounds. To enumerate all audio inputs applications shall begin at index40zero, incrementing by one until the driver returns ``EINVAL``.41 42See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct43:c:type:`v4l2_audio`.44 45Return Value46============47 48On success 0 is returned, on error -1 and the ``errno`` variable is set49appropriately. The generic error codes are described at the50:ref:`Generic Error Codes <gen-errors>` chapter.51 52EINVAL53 The number of the audio input is out of bounds.54