camera_3a.h

Updated: May 06, 2022

Enumerations and functions for configuring 3A algorithms (Auto Focus, Auto Exposure, Auto White Balance) for cameras.

You can configure various manual settings—ISO, shutter speed, white balance color temperature, white balance red and blue gains, aperture, and focus step—after you start the viewfinder on the camera. Changes in these settings may not be visible for several frames due to latency in the image-processing pipeline.

For example, when you use an exposure mode (camera_exposuremode_t) that has a manual component such as CAMERA_EXPOSUREMODE_ISO_PRIORITY and you change the ISO setting (using camera_set_manual_iso()), you may not see the results of the ISO change until several frames later.

Note:
You must start the viewfinder before configuring or retrieving any settings that can be manually set, and any of these other settings:
  • focus state, mode, and regions

  • exposure regions and mode

  • exposure value (EV) offset

  • whitebalance regions and mode

  • the auto focus, auto exposure, and auto white balance locks

Some cameras may not support all available manual settings. You should call camera_get_exposure_modes() to determine which manual exposure settings can be adjusted.