Multimedia
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 and radio devices.
Features
Here are some examples of what can be done with Qt Multimedia APIs:
- Access raw audio devices for input and output
- Play low latency sound effects
- Play media files in playlists (such as compressed audio or video files)
- Record audio and compress it
- Tune and listen to radio stations
- Use a camera, including viewfinder, image capture, and movie recording
- Play 3D positional audio with Qt Audio Engine
- Decode audio media files into memory for processing
- Accessing video frames or audio buffers as they are played or recorded
Multimedia Components
Qt's multimedia APIs are categorized into four main components. More information (including background information and class references) is available here:
Multimedia Recipes
For some quick recipes, look at the overviews above and consult this table:
Limitations
The Qt Multimedia APIs build upon the multimedia framework of the underlying platform. This can mean that support for various codecs or containers can vary between machines, depending on what the end user has installed.
Advanced Usage
For developers wishing to access some platform specific settings, or to port the Qt Multimedia APIs to a new platform or technology, see Multimedia Backend Development.
Changes from Previous Versions
If you previously used Qt Multimedia in Qt 4, or used Qt Multimedia Kit in Qt Mobility, please see Changes in Qt Multimedia for more information on what changed, and what you might need to change when porting code.
Reference Documentation
QML Types
The QML types are accessed by using:
import QtMultimedia 5.8
Add audio playback to a scene | |
Access viewfinder frames, and take photos and movies | |
An interface for capturing camera images | |
An interface for exposure related camera settings | |
An interface for flash related camera settings | |
An interface for focus related camera settings | |
An interface for camera capture related settings | |
Controls video recording with the Camera | |
Add media playback to a scene | |
For specifying a list of media to be played | |
Defines an item in a Playlist | |
Provides a global object with useful functions from Qt Multimedia | |
Access RDS data from a QML application | |
Type provides a way to play sound effects in QML | |
Simple control over torch functionality | |
A convenience type for showing a specified video | |
Render video or camera viewfinder |
The following types are accessed by using Qt Audio Engine:
import QtAudioEngine 1.15
Defines a non-linear attenuation curve for a Sound | |
Defines a linear attenuation curve for a Sound | |
Control all active sound instances by group | |
Organize all your 3d audio content in one place | |
Control global listener parameters | |
Load audio samples, mostly .wav | |
Define a playback variation for sounds. So each time the playback of the same sound can be a slightly different even with the same AudioSample | |
Define a variety of samples and parameters to be used for SoundInstance | |
Play 3d audio content |
Multimedia Classes
Base class for audio backends | |
Access for QAudioInput to access the audio device provided by the plugin | |
Base class for audio backends | |
Abstraction for planar video data | |
Abstraction for video data | |
Represents a filter that is applied to the video frames received by a VideoOutput type | |
Base class for video presentation surfaces | |
Contains enums used by the audio classes | |
Represents a collection of audio samples with a specific format and sample rate | |
Simple wrapper for a stereo audio frame | |
Allows decoding audio | |
Interface to query audio devices and their functionality | |
Set of audio encoder settings | |
Stores audio stream parameter information | |
Interface for receiving audio data from an audio input device | |
Interface for sending audio data to an audio output device | |
Allows you to monitor audio being played or recorded | |
Used for the recording of audio | |
Abstract base for audio plugins | |
Interface for system camera devices | |
A FrameRateRange represents a range of frame rates as minimum and maximum rate | |
Interface for exposure related camera settings | |
Interface for focus and zoom related camera settings | |
Information on zones used for autofocusing a camera | |
Used for the recording of media content | |
Interface for image processing related camera settings | |
General information about camera devices | |
Set of viewfinder settings | |
The base class for all graphics effects | |
Graphics item which display video produced by a QMediaObject | |
Set of image encoder settings | |
The base class for objects extending media objects functionality | |
Access to the resource relating to a media content | |
Provides identifiers for meta-data attributes | |
Common base for multimedia objects | |
Allows the playing of a media source | |
List of media content to play | |
Used for the recording of media content | |
Represents a time interval with integer precision | |
Represents a set of zero or more disjoint time intervals | |
Contains miscellaneous identifiers used throughout the Qt Multimedia library | |
Method to play .wav sound files | |
Way to play low latency sound effects | |
Enables optimized drawing of text when the text and its layout is updated rarely | |
Set of video encoder settings | |
Represents the implementation of a filter that owns all graphics and computational resources, and performs the actual filtering or calculations | |
Represents a frame of video data | |
Allows you to monitor video frames being played or recorded | |
Specifies the stream format of a video presentation surface | |
Widget which presents video produced by a media object |