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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 the QNX OS 8.0.
Graphics
Video Capture Developer's Guide
The video capture framework provides applications the ability to capture frames from a video input source. These frames can be passed to a graphics component such as Screen for display.
Video Capture API (capture.h)
The video capture API includes all the functions, data structures, and constants needed for video capture. It does not handle video display, which should be handled by another component, such as Screen.
capture_release_frame()
Release a video frame buffer

QNX Momentics IDE User's Guide
This User's Guide describes version 8.0 of the Integrated Development Environment (IDE) that's part of the QNX 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 the QNX OS 8.0.
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
- OS Components & Operations
- Graphics
  - Gestures Library Reference
    The Gestures library provides gesture recognizers to detect gestures through touch events that occur when you place one or more fingers on a touch screen.
  - Image Library Reference
  - Input Events Library Reference
    The Input Events library provides the framework necessary for Screen Graphics Subsystem to communicate with your touch driver.
  - OpenWF Configuration Developer's Guide
    If you are integrating a new display, you must configure and provide the parameters of your display based on its specifications via the OpenWF Display Configuration API (Wfdcfg Library).
  - OpenWF Display Server User's Guide
    The OpenWF Display Server (wfd-server) is a resource manager that provides applications the ability to show image buffers directly to the display controller via the OpenWF Display API.
  - Screen Graphics Subsystem Developer's Guide
    QNX Screen Graphics Subsystem is a graphics framework that provides all the functionality necessary to develop interactive user experiences.
  - Video Capture Developer's Guide
    The video capture framework provides applications the ability to capture frames from a video input source. These frames can be passed to a graphics component such as Screen for display.
    - Using Video Capture
      The video capture framework provides applications the ability to capture frames from a video input source. These frames can be passed to a graphics component such as Screen for display.
    - Video Capture Manager
      The Video Capture manager is based on a client/server model where an application is a client that's requesting capture services from the server (Video Capture manager).
    - Video Capture API (capture.h)
      The video capture API includes all the functions, data structures, and constants needed for video capture. It does not handle video display, which should be handled by another component, such as Screen.
      - Properties
        The video capture API includes constants, data types, enumerated values, and macros specifying video capture properties.
      - capture_context_t
        An opaque pointer (or handle) to a video capture context
      - capture_create_buffers()
        Allocate driver-controlled memory for video capture
      - capture_create_context()
        Create a video capture context
      - capture_destroy_context()
        Disconnect from the video capture device, and destroy the video capture context
      - capture_get_frame()
        Get a frame from the video capture device
      - capture_get_free_buffer()
        Get a free video capture buffer when bringing in video from an external source
      - capture_get_property_i()
        Get a video frame capture property of type integer
      - capture_get_property_p()
        Get video frame capture property of type void*
      - capture_is_property()
        Check if the specified property is supported
      - capture_put_buffer()
        Pass a buffer to the driver for deinterlacing a frame when bringing in video from an external source
      - capture_release_frame()
        Release a video frame buffer
      - capture_set_property_i()
        Set a video frame capture property of type integer
      - capture_set_property_p()
        Set a video frame capture property of type (void) pointer
      - capture_update()
        Apply the capture settings
      - Helper macros
        The video capture API includes macros to help with interval conversions.
- Programming
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX OS system and developers who want to create a QNX OS resource manager free from vulnerabilities.
- Utilities & Libraries
- Migrating to QNX OS 8.0
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX OS in the Amazon cloud environment.
QNX Toolkit for Visual Studio Code
This User's Guide describes the QNX^® Toolkit for Visual Studio Code. The guide introduces you to the QNX Toolkit by explaining the QNX development environment and how to build, run, and debug your QNX^® Operating System (OS) applications and systems.
QNX Hypervisor User's Guide
This User's Guide explains the QNX hypervisor architecture and provides instructions for installing and running a QNX Hypervisor system, changing system components and configuration, and using hypervisor features such as virtual devices (vdevs).
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation, explains how to obtain technical support, and provides some information about licensing.

capture_release_frame()

Graphics and Screen4.0 (8.x)Video Capture Developer's GuideAPIProgramming

Release a video frame buffer

Synopsis:

#include <vcapture/capture.h>

int capture_release_frame(capture_context_t context,
                          uint32_t idx)

Arguments:

context: The pointer to the video capture context.
idx: The index to the frame buffer to release.

Library:

libcapture

Description:

This function releases the frame specified in its idx argument and returns it to the capture queue. Your application should call this function after it has displayed a captured frame to ensure that the buffer locked by capture_get_frame() is made available for reuse.

Returns:

0 if successful; or -1 if an error occurred (errno is set; refer to errno.h for more details). The return value and the value that's observed for errno may vary as they are dependent on the implementation by the library that handles your hardware.

Page updated: March 05, 2025