7.11. ioctl VIDIOC_ENUMAUDIO

7.11.1. Name

VIDIOC_ENUMAUDIO - Enumerate audio inputs

7.11.2. Synopsis

int ioctl(int fd, VIDIOC_ENUMAUDIO, struct v4l2_audio *argp)

7.11.3. Arguments

fd

File descriptor returned by open().

argp

Pointer to struct v4l2_audio.

7.11.4. Description

To query the attributes of an audio input applications initialize the index field and zero out the reserved array of a struct v4l2_audio and call the ioctl 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 VIDIOC_G_AUDIO for a description of struct v4l2_audio.

7.11.5. 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 Generic Error Codes chapter.

EINVAL

The number of the audio input is out of bounds.