| .. -*- coding: utf-8; mode: rst -*- | |
| .. _VIDIOC_ENUMAUDIO: | |
| ********************** | |
| ioctl VIDIOC_ENUMAUDIO | |
| ********************** | |
| Name | |
| ==== | |
| VIDIOC_ENUMAUDIO - Enumerate audio inputs | |
| Synopsis | |
| ======== | |
| .. c:function:: int ioctl( int fd, VIDIOC_ENUMAUDIO, struct v4l2_audio *argp ) | |
| :name: VIDIOC_ENUMAUDIO | |
| Arguments | |
| ========= | |
| ``fd`` | |
| File descriptor returned by :ref:`open() <func-open>`. | |
| ``argp`` | |
| Pointer to struct :c:type:`v4l2_audio`. | |
| Description | |
| =========== | |
| To query the attributes of an audio input applications initialize the | |
| ``index`` field and zero out the ``reserved`` array of a struct | |
| :c:type:`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 | |
| :c:type:`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. |