camera_get_specified_vf_framerates()

Updated: April 19, 2023

Retrieve the supported viewfinder frame rates for the specified frame type and resolution

Synopsis:

#include <camera/camera_api.h>
camera_error_t camera_get_specified_vf_framerates(camera_handle_t handle,
                                                  camera_frametype_t frametype,
                                                  camera_res_t resolution,
                                                  uint32_t numasked,
                                                  uint32_t *numsupported,
                                                  double *rates,
                                                  bool *maxmin)

Arguments:

handle
The handle returned by a call to the camera_open() function.
frametype
The frame type to query supported frame rates for (see camera_frametype_t). Using CAMERA_FRAMETYPE_UNSPECIFIED will return the supported frame rates for the currently configured frame type.
resolution
The resolution to query for supported frame rates (see camera_res_t). Using a resolution of (0, 0) will return the supported frame rates for the currently configured resolution.
numasked
The requested number of frame rates to return in the rates array.
numsupported
The returned number of frame rates supported by the specified camera.
rates
A pointer to a double array that is updated with the viewfinder frame rates supported by the camera. If the maxmin flag returns true, the first value returned in the rates array is the maximum supported frame rate, and the second value is the minimum supported frame rate.
maxmin
A pointer to a bool value that specifies how to interpret the rates argument. The maxmin flag is set to true if the values are to be interpreted as a maximum and minimum value; otherwise, it's set to false to indicate that the values describe the discrete viewfinder frame rates that are supported.

Library:

libcamapi

Description:

Use this function to retrieve the supported viewfinder frame rates for the specified resolution and frame type. You can use the values returned by this function to configure the viewfinder frame rate using camera_set_vf_property().

Ensure that the rates argument points to an array that has at least numasked elements allocated. To determine an appropriate size for this array, you can invoke this function in presizing mode by setting the numasked argument to 0 or the rates argument to NULL. The function then returns, in the numsupported argument, the maximum array size required. You can then allocate an array of this size, store its address in rates, and invoke the function again with numasked set to that previous numsupported value.

Returns:

CAMERA_EOK when the function successfully completes, otherwise another camera_error_t value that provides the reason that the call failed.