ioctl VIDIOC_QUERY_DV_TIMINGS
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## Name

VIDIOC_QUERY_DV_TIMINGS — Sense the DV preset received by the current input

## Synopsis

`int ioctl(` | int fd,
| int request,
| struct v4l2_dv_timings *argp`)`;

## Arguments

`fd`

  File descriptor returned by `open()`.

`request`

  VIDIOC_QUERY_DV_TIMINGS

`argp`

## Description

### Experimental

This is an experimental interface and may change in the future.

The hardware may be able to detect the current DV timings automatically, similar to sensing the video standard. To do so, applications call `VIDIOC_QUERY_DV_TIMINGS` with a pointer to a struct v4l2_dv_timings. Once the hardware detects the timings, it will fill in the timings structure. If the timings could not be detected because there was no signal, then ENOLINK is returned. If a signal was detected, but it was unstable and the receiver could not lock to the signal, then ENOLCK is returned. If the receiver could lock to the signal, but the format is unsupported (e.g. because the pixelclock is out of range of the hardware capabilities), then the driver fills in whatever timings it could find and returns ERANGE. In that case the application can call `VIDIOC_DV_TIMINGS_CAP` to compare the found timings with the hardware's capabilities in order to give more precise feedback to the user.

## 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.

ENODATA

  Digital video timings are not supported for this input or output.

ENOLINK

  No timings could be detected because no signal was found.

ENOLCK

  The signal was unstable and the hardware could not lock on to it.

ERANGE

  Timings were found, but they are out of range of the hardware capabilities.

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