VIDIOC_QUERY_DV_TIMINGS — Sense the DV preset received by the current input
int ioctl( | int fd, |
| int request, | |
struct v4l2_dv_timings *argp); |
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.
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.
Digital video timings are not supported for this input or output.
No timings could be detected because no signal was found.
The signal was unstable and the hardware could not lock on to it.
Timings were found, but they are out of range of the hardware capabilities.