VIDIOC_S_HW_FREQ_SEEK — Perform a hardware frequency seek
int ioctl( | int fd, |
| int request, | |
struct v4l2_hw_freq_seek
*argp); |
Start a hardware frequency seek from the current frequency.
To do this applications initialize the tuner,
type, seek_upward,
spacing and
wrap_around fields, and zero out the
reserved array of a struct v4l2_hw_freq_seek and
call the VIDIOC_S_HW_FREQ_SEEK ioctl with a pointer
to this structure.
This ioctl is supported if the V4L2_CAP_HW_FREQ_SEEK capability is set.
Table A.92. struct v4l2_hw_freq_seek
| __u32 | tuner | The tuner index number. This is the
same value as in the struct v4l2_input tuner
field and the struct v4l2_tuner index field. |
| enum v4l2_tuner_type | type | The tuner type. This is the same value as in the
struct v4l2_tuner type field. |
| __u32 | seek_upward | If non-zero, seek upward from the current frequency, else seek downward. |
| __u32 | wrap_around | If non-zero, wrap around when at the end of the frequency range, else stop seeking. |
| __u32 | spacing | If non-zero, defines the hardware seek resolution in Hz. The driver selects the nearest value that is supported by the device. If spacing is zero a reasonable default value is used. |
| __u32 | reserved[7] | Reserved for future extensions. Applications must set the array to zero. |
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.
The tuner index is out of
bounds, the wrap_around value is not supported or the value in the type field is
wrong.
The ioctl timed-out. Try again.