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QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
Sensor Framework
Sensor Framework Libraries
Camera Developer's Guide
The Camera library abstracts the complexity of interfacing with a camera connected to the target board.
Camera Library Reference
camera_3a.h
Enumerations and functions for configuring 3A algorithms (Auto Focus, Auto Exposure, Auto White Balance) for cameras.
camera_set_3a_lock()
Configure the auto focus, auto exposure, and auto white balance (the 3A algorithms) locks on the camera

QNX Momentics IDE User's Guide
This User's Guide describes version 7.1 of the Integrated Development Environment (IDE) that's part of the QNX Momentics tool suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
- Quickstart Guide
- OS Components & Operations
- Audio & Graphics API
- Multimedia
- Networking Middleware
- Programming
- Sensor Framework
  - Architecture
  - Getting Started
    This guide gets you started with the Sensor Framework for QNX SDP.
  - Sensor Framework Libraries
    - ADAS Library Developer's Guide
      The ADAS library facilitates the development of embedded systems that rely on sensor data.
    - Camera Developer's Guide
      The Camera library abstracts the complexity of interfacing with a camera connected to the target board.
      - Camera Library Overview
        The Camera library provides applications with an interface to interact with cameras connected to your system. The library supports up to 64 cameras but the actual limit depends on your hardware platform's limitations and resources.
      - Viewfinder Window
        By default, the Camera library creates a viewfinder window.
      - Settings on the Camera
        You can configure various settings on the camera to modify the ISO, aperture, shutter speed, framerate, resolution, format, etc.
      - Image Buffer Access
        The Camera library supports read-only and read-write access to the image from different stages in the imaging datapath. Applications access image buffers by binding callback functions or events to a particular stage of the imaging datapath. Alternatively, applications can use streams from the Screen API to access buffers. In this guide, access to the imaging datapath is referred to as image buffers.
      - External Camera Drivers
        Cameras that aren't already supported by the Sensor Framework for QNX SDP can be supported by an external camera driver library.
      - Show a Video Stream from a Camera
        You can use the Camera library to show a video stream (image buffers) from a live camera or file camera. This section shows you the basic workflow for doing so.
      - Camera Library Reference
        camera_api.h
        The main definitions and functions for the Camera Library.
        camera_encoder.h
        Functions to configure parameters for video encoding.
        camera_h264avc.h
        Supported H.264/AVC video encoder parameters.
        camera_3a.h
        Enumerations and functions for configuring 3A algorithms (Auto Focus, Auto Exposure, Auto White Balance) for cameras.
        camera_3a_t
        The autofocus, auto exposure, and auto white balance algorithms (3A)
        camera_exposuremode_t
        The exposure mode of the camera
        camera_focusmode_t
        The focus mode of the camera
        camera_focusstate_t
        The state of the autofocus algorithm on the camera
        camera_get_3a_lock_modes()
        Retrieve the list of supported 3A lock modes on the camera
        camera_get_ev_offset()
        Retrieve the current exposure value (EV) offset for exposure compensation
        camera_get_exposure_mode()
        Retrieve the exposure mode from the camera
        camera_get_exposure_modes()
        Retrieve the exposure modes that are available on the camera
        camera_get_exposure_regions()
        Retrieve the exposure regions configured on the camera
        camera_get_focus_mode()
        Retrieve the current focus mode of the camera
        camera_get_focus_modes()
        Retrieve the focus modes available on the camera
        camera_get_focus_regions()
        Retrieve the focus regions configured on the camera
        camera_get_focus_state()
        Retrieve the focus state of the camera
        camera_get_manual_aperture()
        Retrieve the current manual aperture value (f-number)
        camera_get_manual_focus_step()
        Retrieve the current manual focus lens position and range
        camera_get_manual_iso()
        Retrieve the current manual ISO value
        camera_get_manual_shutter_speed()
        Retrieve the current manual shutter speed
        camera_get_manual_white_balance()
        Retrieve the manual white balance color temperature
        camera_get_manual_white_balance_rb_gain()
        Retrieve the manual white balance red and blue gains
        camera_get_supported_ev_offsets()
        Retrieve the supported EV offset values
        camera_get_supported_manual_aperture_values()
        Retrieve the supported manual aperture values (f-numbers)
        camera_get_supported_manual_iso_values()
        Retrieve the supported manual ISO values
        camera_get_supported_manual_shutter_speeds()
        Retrieve the supported manual shutter speeds
        camera_get_supported_manual_white_balance_values()
        Retrieve the supported manual white balance color temperature values
        camera_get_supported_manual_white_balance_rb_gain()
        Retrieve the supported manual white balance red/blue gain values
        camera_get_whitebalance_mode()
        Retrieve the white balance mode from the camera
        camera_get_whitebalance_modes()
        Retrieve the white balance modes that are available on the camera
        camera_get_whitebalance_regions()
        Retrieve the white balance regions configured on the camera
        camera_set_3a_lock()
        Configure the auto focus, auto exposure, and auto white balance (the 3A algorithms) locks on the camera
        camera_set_ev_offset()
        Set the exposure value (EV) offset for exposure compensation
        camera_set_exposure_mode()
        Configure the exposure mode on the camera
        camera_set_exposure_regions()
        Configure the auto exposure regions on the camera
        camera_set_manual_aperture()
        Change the manual aperture value (f-number) on the camera
        camera_set_manual_focus_step()
        Manually adjust the lens position on the camera
        camera_set_manual_iso()
        Change the manual ISO value on the camera
        camera_set_manual_shutter_speed()
        Change the manual shutter speed
        camera_set_manual_white_balance()
        Change the manual white balance color temperature
        camera_set_manual_white_balance_rb_gain()
        Change the manual white balance red and blue gains
        camera_set_whitebalance_mode()
        Configure the white balance mode on the camera
        camera_set_whitebalance_regions()
        Configure the white balance regions on the camera
        camera_whitebalancemode_t
        The white balance mode of the camera
        external_camera_api.h
        Definitions and functions to use the External Camera library.
    - Sensor Developer's Guide
      The Sensor library abstracts the complexity of interfacing with sensors and cameras connected to the target board.
  - Sensor Framework Services
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX Neutrino RTOS system and developers who want to create a QNX Neutrino resource manager free from vulnerabilities.
- Utilities & Libraries
QNX Hypervisor
The QNX Hypervisor allows you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX software in Amazon Web Services (AWS) and Microsoft Azure (Azure).
QNX Advanced Virtualization Frameworks User's Guide
This User's Guide is aimed at all systems integrators and developers who want to design and build embedded systems using the QNX Advanced Virtualization Frameworks.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

camera_set_3a_lock()

Configure the auto focus, auto exposure, and auto white balance (the 3A algorithms) locks on the camera

Synopsis:

#include <camera/camera_3a.h>

camera_error_t camera_set_3a_lock(camera_handle_t handle,
                                  uint32_t locks)

Arguments:

handle: The handle returned by a call to the camera_open() function.
locks: A bitmask of 3A algorithms to lock on the camera.

Library:

libcamapi

Description:

For the locks argument, you can specify the 3A algorithms to lock by ORing values from the camera_3a_t enumerated type. The following are examples:

To unlock auto focus, auto exposure, and auto white balance, use the value of CAMERA_3A_NONE.
To lock auto focus and auto exposure and unlock auto white balance, use the value of (CAMERA_3A_AUTOFOCUS | CAMERA_3A_AUTOEXPOSURE).

Note:

Not all cameras allow the independent locking of individual 3A algorithms. For example, it may be required that auto exposure and auto white balance be locked together. Use the camera_get_3a_lock_modes() function to discover these restrictions.

Returns:

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

Page updated: March 12, 2026