1059b1c5bSMauro Carvalho Chehab.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2407e84cdSMauro Carvalho Chehab.. c:namespace:: V4L 354f38fcaSMauro Carvalho Chehab 454f38fcaSMauro Carvalho Chehab.. _VIDIOC_G_AUDIO: 554f38fcaSMauro Carvalho Chehab 654f38fcaSMauro Carvalho Chehab************************************ 754f38fcaSMauro Carvalho Chehabioctl VIDIOC_G_AUDIO, VIDIOC_S_AUDIO 854f38fcaSMauro Carvalho Chehab************************************ 954f38fcaSMauro Carvalho Chehab 1054f38fcaSMauro Carvalho ChehabName 1154f38fcaSMauro Carvalho Chehab==== 1254f38fcaSMauro Carvalho Chehab 1354f38fcaSMauro Carvalho ChehabVIDIOC_G_AUDIO - VIDIOC_S_AUDIO - Query or select the current audio input and its attributes 1454f38fcaSMauro Carvalho Chehab 1554f38fcaSMauro Carvalho ChehabSynopsis 1654f38fcaSMauro Carvalho Chehab======== 1754f38fcaSMauro Carvalho Chehab 18407e84cdSMauro Carvalho Chehab.. c:macro:: VIDIOC_G_AUDIO 1954f38fcaSMauro Carvalho Chehab 20407e84cdSMauro Carvalho Chehab``int ioctl(int fd, VIDIOC_G_AUDIO, struct v4l2_audio *argp)`` 2154f38fcaSMauro Carvalho Chehab 22407e84cdSMauro Carvalho Chehab.. c:macro:: VIDIOC_S_AUDIO 23407e84cdSMauro Carvalho Chehab 24407e84cdSMauro Carvalho Chehab``int ioctl(int fd, VIDIOC_S_AUDIO, const struct v4l2_audio *argp)`` 2554f38fcaSMauro Carvalho Chehab 2654f38fcaSMauro Carvalho ChehabArguments 2754f38fcaSMauro Carvalho Chehab========= 2854f38fcaSMauro Carvalho Chehab 2954f38fcaSMauro Carvalho Chehab``fd`` 30407e84cdSMauro Carvalho Chehab File descriptor returned by :c:func:`open()`. 3154f38fcaSMauro Carvalho Chehab 3254f38fcaSMauro Carvalho Chehab``argp`` 3354f38fcaSMauro Carvalho Chehab Pointer to struct :c:type:`v4l2_audio`. 3454f38fcaSMauro Carvalho Chehab 3554f38fcaSMauro Carvalho ChehabDescription 3654f38fcaSMauro Carvalho Chehab=========== 3754f38fcaSMauro Carvalho Chehab 3854f38fcaSMauro Carvalho ChehabTo query the current audio input applications zero out the ``reserved`` 3954f38fcaSMauro Carvalho Chehabarray of a struct :c:type:`v4l2_audio` and call the 4054f38fcaSMauro Carvalho Chehab:ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` ioctl with a pointer to this structure. Drivers fill 4154f38fcaSMauro Carvalho Chehabthe rest of the structure or return an ``EINVAL`` error code when the device 4254f38fcaSMauro Carvalho Chehabhas no audio inputs, or none which combine with the current video input. 4354f38fcaSMauro Carvalho Chehab 4454f38fcaSMauro Carvalho ChehabAudio inputs have one writable property, the audio mode. To select the 4554f38fcaSMauro Carvalho Chehabcurrent audio input *and* change the audio mode, applications initialize 4654f38fcaSMauro Carvalho Chehabthe ``index`` and ``mode`` fields, and the ``reserved`` array of a 4754f38fcaSMauro Carvalho Chehabstruct :c:type:`v4l2_audio` structure and call the :ref:`VIDIOC_S_AUDIO <VIDIOC_G_AUDIO>` 4854f38fcaSMauro Carvalho Chehabioctl. Drivers may switch to a different audio mode if the request 4954f38fcaSMauro Carvalho Chehabcannot be satisfied. However, this is a write-only ioctl, it does not 5054f38fcaSMauro Carvalho Chehabreturn the actual new audio mode. 5154f38fcaSMauro Carvalho Chehab 52*fea13a69SMauro Carvalho Chehab.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| 5354f38fcaSMauro Carvalho Chehab 5454f38fcaSMauro Carvalho Chehab.. c:type:: v4l2_audio 5554f38fcaSMauro Carvalho Chehab 5654f38fcaSMauro Carvalho Chehab.. flat-table:: struct v4l2_audio 5754f38fcaSMauro Carvalho Chehab :header-rows: 0 5854f38fcaSMauro Carvalho Chehab :stub-columns: 0 5954f38fcaSMauro Carvalho Chehab :widths: 1 1 2 6054f38fcaSMauro Carvalho Chehab 6154f38fcaSMauro Carvalho Chehab * - __u32 6254f38fcaSMauro Carvalho Chehab - ``index`` 6354f38fcaSMauro Carvalho Chehab - Identifies the audio input, set by the driver or application. 6454f38fcaSMauro Carvalho Chehab * - __u8 6554f38fcaSMauro Carvalho Chehab - ``name``\ [32] 6654f38fcaSMauro Carvalho Chehab - Name of the audio input, a NUL-terminated ASCII string, for 6754f38fcaSMauro Carvalho Chehab example: "Line In". This information is intended for the user, 6854f38fcaSMauro Carvalho Chehab preferably the connector label on the device itself. 6954f38fcaSMauro Carvalho Chehab * - __u32 7054f38fcaSMauro Carvalho Chehab - ``capability`` 7154f38fcaSMauro Carvalho Chehab - Audio capability flags, see :ref:`audio-capability`. 7254f38fcaSMauro Carvalho Chehab * - __u32 7354f38fcaSMauro Carvalho Chehab - ``mode`` 7454f38fcaSMauro Carvalho Chehab - Audio mode flags set by drivers and applications (on 7554f38fcaSMauro Carvalho Chehab :ref:`VIDIOC_S_AUDIO <VIDIOC_G_AUDIO>` ioctl), see :ref:`audio-mode`. 7654f38fcaSMauro Carvalho Chehab * - __u32 7754f38fcaSMauro Carvalho Chehab - ``reserved``\ [2] 7854f38fcaSMauro Carvalho Chehab - Reserved for future extensions. Drivers and applications must set 7954f38fcaSMauro Carvalho Chehab the array to zero. 8054f38fcaSMauro Carvalho Chehab 8154f38fcaSMauro Carvalho Chehab 82*fea13a69SMauro Carvalho Chehab.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.5cm}| 8354f38fcaSMauro Carvalho Chehab 8454f38fcaSMauro Carvalho Chehab.. _audio-capability: 8554f38fcaSMauro Carvalho Chehab 8654f38fcaSMauro Carvalho Chehab.. flat-table:: Audio Capability Flags 8754f38fcaSMauro Carvalho Chehab :header-rows: 0 8854f38fcaSMauro Carvalho Chehab :stub-columns: 0 8954f38fcaSMauro Carvalho Chehab :widths: 3 1 4 9054f38fcaSMauro Carvalho Chehab 9154f38fcaSMauro Carvalho Chehab * - ``V4L2_AUDCAP_STEREO`` 9254f38fcaSMauro Carvalho Chehab - 0x00001 9354f38fcaSMauro Carvalho Chehab - This is a stereo input. The flag is intended to automatically 9454f38fcaSMauro Carvalho Chehab disable stereo recording etc. when the signal is always monaural. 9554f38fcaSMauro Carvalho Chehab The API provides no means to detect if stereo is *received*, 9654f38fcaSMauro Carvalho Chehab unless the audio input belongs to a tuner. 9754f38fcaSMauro Carvalho Chehab * - ``V4L2_AUDCAP_AVL`` 9854f38fcaSMauro Carvalho Chehab - 0x00002 9954f38fcaSMauro Carvalho Chehab - Automatic Volume Level mode is supported. 10054f38fcaSMauro Carvalho Chehab 10154f38fcaSMauro Carvalho Chehab 102*fea13a69SMauro Carvalho Chehab.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.5cm}| 10354f38fcaSMauro Carvalho Chehab 10454f38fcaSMauro Carvalho Chehab.. _audio-mode: 10554f38fcaSMauro Carvalho Chehab 10654f38fcaSMauro Carvalho Chehab.. flat-table:: Audio Mode Flags 10754f38fcaSMauro Carvalho Chehab :header-rows: 0 10854f38fcaSMauro Carvalho Chehab :stub-columns: 0 10954f38fcaSMauro Carvalho Chehab :widths: 3 1 4 11054f38fcaSMauro Carvalho Chehab 11154f38fcaSMauro Carvalho Chehab * - ``V4L2_AUDMODE_AVL`` 11254f38fcaSMauro Carvalho Chehab - 0x00001 11354f38fcaSMauro Carvalho Chehab - AVL mode is on. 11454f38fcaSMauro Carvalho Chehab 11554f38fcaSMauro Carvalho ChehabReturn Value 11654f38fcaSMauro Carvalho Chehab============ 11754f38fcaSMauro Carvalho Chehab 11854f38fcaSMauro Carvalho ChehabOn success 0 is returned, on error -1 and the ``errno`` variable is set 11954f38fcaSMauro Carvalho Chehabappropriately. The generic error codes are described at the 12054f38fcaSMauro Carvalho Chehab:ref:`Generic Error Codes <gen-errors>` chapter. 12154f38fcaSMauro Carvalho Chehab 12254f38fcaSMauro Carvalho ChehabEINVAL 12354f38fcaSMauro Carvalho Chehab No audio inputs combine with the current video input, or the number 12454f38fcaSMauro Carvalho Chehab of the selected audio input is out of bounds or it does not combine. 125