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diff --git a/Documentation/media/uapi/v4l/vidioc-enumaudio.rst b/Documentation/media/uapi/v4l/vidioc-enumaudio.rst new file mode 100644 index 0000000..bfdc353 --- /dev/null +++ b/Documentation/media/uapi/v4l/vidioc-enumaudio.rst @@ -0,0 +1,56 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _VIDIOC_ENUMAUDIO: + +********************** +ioctl VIDIOC_ENUMAUDIO +********************** + +Name +==== + +VIDIOC_ENUMAUDIO - Enumerate audio inputs + + +Synopsis +======== + +.. cpp:function:: int ioctl( int fd, int request, struct v4l2_audio *argp ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``request`` + VIDIOC_ENUMAUDIO + +``argp`` + + +Description +=========== + +To query the attributes of an audio input applications initialize the +``index`` field and zero out the ``reserved`` array of a struct +:ref:`v4l2_audio <v4l2-audio>` and call the :ref:`VIDIOC_ENUMAUDIO` +ioctl with a pointer to this structure. Drivers fill the rest of the +structure or return an ``EINVAL`` error code when the index is out of +bounds. To enumerate all audio inputs applications shall begin at index +zero, incrementing by one until the driver returns ``EINVAL``. + +See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct +:ref:`v4l2_audio <v4l2-audio>`. + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EINVAL + The number of the audio input is out of bounds. |