Multimedia Overview¶
A set of APIs for working with audio, video and camera devices.
Multimedia support in Qt is provided by the 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.
Features¶
Here are some things you can do with the Qt Multimedia APIs:
Access raw audio devices for input and output.
Play low latency sound effects.
Play 3D spatial audio.
Play media files in playlists (such as compressed audio or video files).
Record audio and compress it.
Use a camera, including viewfinder, image capture, and movie recording
Decode audio media files into memory for processing.
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 recipes .
Spatial Audio Overview (Technology Preview)
Multimedia Recipes¶
For some quick recipes, see this table:
Use case
Examples
QML Types
C++ Classes
Playing a sound effect
Playing 3D sound
audiopanning
SpatialSound, AudioEngine
QSpatialSound, QAudioEngine
Playing encoded audio (MP3, AAC etc)
player
Playing raw audio data with low latency
audiooutput
Accessing raw audio input data
audiosource
Recording encoded audio data
audiorecorder
Discovering audio and video devices
audiodevices
Video Playback
player , mediaplayer
Capturing audio and video
camera , recorder
Capturing photos
camera , recorder
Capturing movies
camera , recorder
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 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 Multimedia-Security-Considerations page describing security-related data flow and exploiting risks.
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 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.
Changes from Previous Versions¶
If you previously used Qt Multimedia in Qt 5, see Changes-to-Qt-Multimedia for more information on what has changed, and what you might need to change when porting code to Qt 6.