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// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
/*!
\page qtmultimedia-index.html
\title Qt Multimedia
\image noun_Media_166644.svg "image of multimedia icons, courtesy of misirlou from the Noun Project"
\brief The Qt Multimedia module provides APIs for playing back and recording
audiovisual content
Qt Multimedia is an add-on module that provides a rich set of QML types
and C++ classes to handle multimedia content. It contains an easy to use
API for playing back audio and video files and rendering those on screen, as
well as a comprehensive API for recording audio and video from the systems
cameras and microphones.
The functionality of this module is divided into the following submodules:
\table
\row
\li \l{Multimedia Overview}{Qt Multimedia}
\li Provides API for multimedia-specific use cases.
\row
\li \l{Qt Multimedia Widgets}
\li Provides the widget-based multimedia API.
\endtable
\section1 Getting started
If you are porting from Qt 5 to Qt 6 see \l{Changes to Qt Multimedia}.
If you are new to Qt Multimedia, the QML types can be
\l{qtqml import syntax}{imported} into an application using the following
statement in your \c {.qml} file.
\qml
import QtMultimedia
\endqml
To link against the C++ libraries, add the following to your project's
\c CMakeLists.txt file. Substitute \c my_project with the name of your
project.
\code
find_package(Qt6 REQUIRED COMPONENTS Multimedia)
target_link_libraries(my_project PRIVATE Qt6::Multimedia)
\endcode
\section1 Overviews and Important Topics
\list
\li \l{Changes to Qt Multimedia}{Changes in Qt 6}
\li \l{Multimedia Overview}
\li \l{Audio Overview}
\li \l{Video Overview}
\li \l{Camera Overview}
\li \l{Supported Media Formats}
\endlist
\section1 QML Types
The following table outlines some important QML types.
\table
\header
\li Type
\li Description
\row
\li \l{MediaPlayer}
\li Add audio/video playback functionality to a scene.
\row
\li \l {QtMultimedia::CaptureSession}{CaptureSession}
\li Create a session for capturing audio/video.
\row
\li \l {QtMultimedia::Camera}{Camera}
\li Access a camera connected to the system.
\row
\li \l {QtMultimedia::AudioInput}{AudioInput}
\li Access an audio input (microphone) connected to the system.
\row
\li \l {QtMultimedia::AudioOutput}{AudioOutput}
\li Access an audio output (speaker, headphone) connected to the system.
\row
\li \l {QtMultimedia::VideoOutput}{VideoOutput}
\li Display video content.
\row
\li \l {QtMultimedia::MediaRecorder}{MediaRecorder}
\li Record audio/video from the CaptureSession.
\row
\li \l {QtMultimedia::ImageCapture}{ImageCapture}
\li Capture still images from the Camera.
\row
\li \l {QtMultimedia::Video}{Video}
\li Add Video playback functionality to a scene. Uses MediaPlayer and
VideoOutput types to provide video playback functionality.
\endtable
\section1 C++ Classes
The following table outlines some important C++ Classes
\table
\header
\li Class
\li Description
\row
\li QMediaPlayer
\li Playback media from a source.
\row
\li QVideoWidget
\li Display video from a media player or a capture session.
\row
\li QMediaCaptureSession
\li Capture audio and video.
\row
\li QCamera
\li Access a camera connected to the system
\row
\li QAudioInput
\li Access an audio input (microphone) connected to the system.
\row
\li QAudioOutput
\li Access an audio output (speaker, headphone) connected to the system.
\row
\li QImageCapture
\li Capture still images with a camera.
\row
\li QMediaRecorder
\li Record media content from a capture session.
\row
\li QVideoSink
\li Access and render individual video frames.
\row
\li QAudioSink
\li Sends raw audio data to an audio output device.
\endtable
For playback QMediaPlayer, QAudioOutput and QVideoOutput contain all the required functionality.
The other classes are used for capturing audio and video content, where the QMediaCaptureSession is the central
class managing the whole capture/recording process.
\section1 Licenses and Attributions
The Qt Multimedia module is available under commercial licenses from
\l{The Qt Company}.
In addition, it is available under free software licenses. Since Qt 5.6,
these free software licenses are
\l{GNU Lesser General Public License, version 3}, or
the \l{GNU General Public License, version 2}.
See \l{Qt Licensing} for further details.
The FFmpeg backend uses the \l {https://ffmpeg.org}{FFmpeg framework}. FFmpeg is licensed under
LGPLv2.1, GPLv2, or later versions of the licenses. Some optional components of FFmpeg are only
available under GPL. The FFmpeg backend shipped with the Qt binary packages is configured to not
contain any of the components that are available under GPLv2 only.
See the \l {https://ffmpeg.org/legal.html}{FFmpeg licensing page} for further details.
\section1 Target platform and backend notes
On most platforms, there are two different backends that can be used for Qt Multimedia.
The first one is the backend built on the native multimedia framework of the underlying
operating system. This is currently the default, and will use gstreamer on Linux,
AVFoundation on macOS/iOS, WMF on Windows, and the MediaCodec framework on Android.
While we try to support our full API on all backends using the native multimedia framework,
platform specific limitations do
exist in a few places. This is due to the fact that the feature set supported by those
frameworks varies, implying that some functionality
might not be available on all platforms. This is especially true for the set of
supported file formats and codecs, as well as advanced camera functionality.
Where limitations exist, we aim to document those in the respective classes and
methods.
With Qt 6.4, we are adding a new, more platform independent backend based on the
\l {http://ffmpeg.org}{FFmpeg framework}. The FFmpeg backend is currently available as a
technology preview. This backend has the advantage that we can offer proper cross-platform
support for all features of Qt Multimedia, going beyond the limitations that exist with many
of the native frameworks.
You can test the FFmpeg backend right now by using a Qt build that has FFmpeg enabled and
setting the \c{QT_MEDIA_BACKEND} environment variable to ffmpeg:
\code
export QT_MEDIA_BACKEND=ffmpeg
\endcode
\list
\li \l{Qt Multimedia on macOS and iOS}{macOS and iOS}
\endlist
\section1 Reference and Examples
\list
\li \l{Qt Multimedia QML Types}{QML Types}
\li \l{Qt Multimedia C++ Classes}{C++ Classes}
\li \l{Qt Multimedia Examples}{Examples}
\endlist
*/
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