Video for Linux Two API Specification: Revision 0.24
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ioctl VIDIOC_ENUMAUDIO

Name

VIDIOC_ENUMAUDIO -- Enumerate audio inputs

Synopsis

int ioctl(int fd, int request, struct v4l2_audio *argp);

Arguments

fd

File descriptor returned by 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 v4l2_audio and call the 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 ioctl VIDIOC_G_AUDIO, VIDIOC_S_AUDIO(2) for a description of struct v4l2_audio.

Return Value

On success 0 is returned, on error -1 and the errno variable is set appropriately:

EINVAL

The number of the audio input is out of bounds, or there are no audio inputs at all and this ioctl is not supported.

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ioctl VIDIOC_ENCODER_CMD, VIDIOC_TRY_ENCODER_CMDUpioctl VIDIOC_ENUMAUDOUT