multimedia-overview.qdoc

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// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
 
 
 
/*!
\page multimediaoverview.html
\title Multimedia Overview
\brief A set of APIs for working with audio, video and camera devices.
\ingroup explanations-graphicsandmultimedia
 
Multimedia support in Qt is provided by the \l{Qt Multimedia} module. The Qt
Multimedia module provides a rich feature set that enables you to easily take
advantage of a platform's multimedia capabilities, such as media playback and
the use of camera devices.
 
\section1 Features
 
Here are some things you can do with the Qt Multimedia APIs:
 
\list
\li Access raw audio devices for input and output.
\li Play low latency sound effects.
\li Play 3D spatial audio.
\li Play media files in playlists (such as compressed audio or video files).
\li Record audio and compress it.
\li Use a camera, including viewfinder, image capture, and movie recording
\li Decode audio media files into memory for processing.
\endlist
 
\section1 Multimedia Components
 
The Qt Multimedia APIs are categorized into three main components. More
information specific to each component is available in the overview pages. You
can also take a look at some \l{Multimedia Recipes}{recipes}.
 
\list
\li \l {Audio Overview}
\li \l {Video Overview}
\li \l {Camera Overview}
\li \l {Spatial Audio Overview} (Technology Preview)
\endlist
 
\section1 Multimedia Recipes
 
For some quick recipes, see this table:
 
\table 70%
    \header
        \li Use case
        \li Examples
        \li QML Types
        \li C++ Classes
    \row
        \li Playing a sound effect
        \li
        \li \l{SoundEffect}
        \li QSoundEffect
    \row
        \li Playing 3D sound
        \li \l{Spatial Audio Panning Example}{audiopanning}
        \li SpatialSound, AudioEngine
        \li QSpatialSound, QAudioEngine
    \row
        \li Playing encoded audio (MP3, AAC etc)
        \li \l{Media Player Example}{player}
        \li \l{MediaPlayer}
        \li QMediaPlayer
    \row
        \li Playing raw audio data with low latency
        \li \l{Audio Output Example}{audiooutput}
        \li
        \li QAudioSink
    \row
        \li Accessing raw audio input data
        \li \l{Audio Source Example}{audiosource}
        \li
        \li QAudioSource
    \row
        \li Recording encoded audio data
        \li \l{Audio Recorder Example}{audiorecorder}
        \li \l{CaptureSession}, \l{AudioInput}, \l{MediaRecorder}
        \li QMediaCaptureSession, QAudioInput, QMediaRecorder
    \row
        \li Discovering audio and video devices
        \li \l{Audio Devices Example}{audiodevices}
        \li \l{MediaDevices}, \l{audioDevice}, \l{cameraDevice}
        \li QMediaDevices, QAudioDevice, QCameraDevice
    \row
        \li Video Playback
        \li \l{Media Player Example}{player},
            \l{QML Media Player Example}{mediaplayer}
        \li \l MediaPlayer, \l VideoOutput, \l Video
        \li QMediaPlayer, QVideoWidget, QGraphicsVideoItem
    \row
        \li Capturing audio and video
        \li \l {Camera Example}{camera},
            \l {QML Video Recorder}{recorder}
        \li \l CaptureSession, \l Camera, \l AudioInput \l VideoOutput
        \li QMediaCaptureSession, QCamera, QAudioInput, QVideoWidget
    \row
        \li Capturing photos
        \li \l {Camera Example}{camera},
            \l {QML Video Recorder}{recorder}
        \li \l CaptureSession, \l Camera, \l ImageCapture
        \li QMediaCaptureSession, QCamera, QImageCapture
    \row
        \li Capturing movies
        \li \l {Camera Example}{camera},
            \l {QML Video Recorder}{recorder}
        \li \l CaptureSession, \l Camera, \l MediaRecorder
        \li QMediaCaptureSession, QCamera, QMediaRecorder
\endtable
 
\section1 Multimedia Security Notes
 
Qt Multimedia relies heavily on media hardware and its drivers.
Therefore, we highly recommend using trusted hardware, such as cameras,
audio devices, graphics cards, and other peripherals, as well as
a properly configured environment to avoid unexpected Qt Multimedia behavior
that could result in security-critical issues.
 
Qt Multimedia components, such as QMediaPlayer, QAudioDecoder,
and QGStreamerVideoSource may process untrusted media sources.
When using these components, follow the general best practices for
\l{Handling Untrusted Data}{handling untrusted data}.
We aim to keep Qt Multimedia secure regardless of the media file
or stream provided as input. However, the module highly depends on third-party
libraries, such as FFmpeg and GStreamer, resulting in a long processing
data chain that may be vulnerable to security issues if a flaw exists
at any stage. See \l{Multimedia Security Considerations} page describing
security-related data flow and exploiting risks.
 
\section1 Limitations
 
The Qt Multimedia APIs build upon the multimedia framework of the underlying
platform. This can mean that support for various codecs, or containers will vary
between machines. This support depends on what the end user has installed.
See \l{Supported Media Formats} for more detail.
 
\note Qt Multimedia APIs depend on functionality provided by QCoreApplication,
and multimedia objects created using the Qt Multimedia APIs can only be used
during the lifetime of this application object. It is therefore important to
create a QCoreApplication, QGuiApplication, or QApplication before accessing
any of the Qt Multimedia APIs. If the application object is recreated, make
sure that any Qt Multimedia objects are also recreated.
 
\section1 Changes from Previous Versions
 
If you previously used Qt Multimedia in Qt 5, see
\l{Changes to Qt Multimedia} for more information on what has changed, and what
you might need to change when porting code to Qt 6.
 
\section1 Reference Documentation
 
\list
    \li \l{Qt Multimedia C++ Classes}{C++ Classes}
    \li \l{Qt Multimedia QML Types}{QML Types}
\endlist
*/