Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) .. c:namespace:: V4L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) .. _VIDIOC_ENUMAUDOUT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) ***********************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) ioctl VIDIOC_ENUMAUDOUT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) ***********************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) ====
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) VIDIOC_ENUMAUDOUT - Enumerate audio outputs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Synopsis
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) ========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) .. c:macro:: VIDIOC_ENUMAUDOUT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) ``int ioctl(int fd, VIDIOC_ENUMAUDOUT, struct v4l2_audioout *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) Arguments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) =========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) ``fd``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)     File descriptor returned by :c:func:`open()`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) ``argp``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)     Pointer to struct :c:type:`v4l2_audioout`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) Description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) ===========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) To query the attributes of an audio output applications initialize the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) ``index`` field and zero out the ``reserved`` array of a struct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) :c:type:`v4l2_audioout` and call the ``VIDIOC_G_AUDOUT``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) ioctl with a pointer to this structure. Drivers fill the rest of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) structure or return an ``EINVAL`` error code when the index is out of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) bounds. To enumerate all audio outputs applications shall begin at index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) zero, incrementing by one until the driver returns ``EINVAL``.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) .. note::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)     Connectors on a TV card to loop back the received audio signal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)     to a sound card are not audio outputs in this sense.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) See :ref:`VIDIOC_G_AUDIOout <VIDIOC_G_AUDOUT>` for a description of struct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) :c:type:`v4l2_audioout`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) Return Value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) ============
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) On success 0 is returned, on error -1 and the ``errno`` variable is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) appropriately. The generic error codes are described at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) :ref:`Generic Error Codes <gen-errors>` chapter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) EINVAL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)     The number of the audio output is out of bounds.