ioctl VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT
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Name

VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT — Query or select the current video output

Synopsis

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

Arguments

fd

File descriptor returned by open().

request

VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT

argp

Description

To query the current video output applications call the VIDIOC_G_OUTPUT ioctl with a pointer to an integer where the driver stores the number of the output, as in the struct v4l2_output index field. This ioctl will fail only when there are no video outputs, returning the EINVAL error code.

To select a video output applications store the number of the desired output in an integer and call the VIDIOC_S_OUTPUT ioctl with a pointer to this integer. Side effects are possible. For example outputs may support different video standards, so the driver may implicitly switch the current standard. It is good practice to select an output before querying or negotiating any other parameters.

Information about video outputs is available using the VIDIOC_ENUMOUTPUT ioctl.

Return Value

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

EINVAL

The number of the video output is out of bounds, or there are no video outputs at all and this ioctl is not supported.

EBUSY

I/O is in progress, the output cannot be switched.

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ioctl VIDIOC_G_MODULATOR, VIDIOC_S_MODULATOR Home ioctl VIDIOC_G_PARM, VIDIOC_S_PARM