Qt 5.4 Multimedia Backends

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For most features, Qt Multimedia builds upon the multimedia framework of the underlying system. Therefore there are several multimedia backends based on different technologies and APIs. The glue between platform specific libraries and Qt Multimedia is contained in a plugin. There are currently three kinds of plugins in Qt Multimedia:

  • MediaService plugins, to provide media player, camera, radio, and recording features
  • Audio plugins, to provide low-latency audio support
  • PlaylistFormat plugins, to support a specific playlist file format

Plugins do not necessarily implement all possible features and different backends have different capabilities. The following tables give an overview of what is supported by each backend in Qt 5.4.

MediaService plugins

Supported media player features by backend

DirectShow (Windows) Media Foundation (Windows) AV Foundation (Mac OS / iOS) GStreamer (Unix) Android BlackBerry
MediaPlayer control X X X X X X
URL source (local and remote) X X X X X X
Stream source X X X
Metadata X X partial X X X
Playback rate X X X X X
Track selection X
HW decoding Only when using Angle X X X
Video window control X X X X X
Video widget control X X
Video renderer control (includes OpenGL textures) X X X (only Mac OS) X X X
Audio probe X X
Video Probe X X

Supported camera features by backend

DirectShow (Windows) Media Foundation (Windows) AV Foundation (Mac OS / iOS) GStreamer (Unix) Android BlackBerry
Camera control X X X X X
Video window control X
Video widget control X X
Video renderer control (includes OpenGL textures) X X X X X
ViewFinder settings resolution resolution, framerate, pixel format
Image capture X X X X X
Capture destination File File File, Buffer File, Buffer File, Buffer
Image settings resolution resolution, quality resolution, quality
Zoom X X X
Flash X X X
Focus only focused notification mode, custom point mode, custom point
Exposure Scene mode, compensation, ISO, aperture, ShutterSpeed Scene mode, compensation Scene mode
Image Processing White Balance, Contrast, Brightness, Saturation, White Balance White Balance
Locks Focus Focus, Exposure, White Balance Focus, Exposure, White Balance

Supported recording features by backend

DirectShow (Windows) Media Foundation (Windows) AV Foundation (Mac OS / iOS) GStreamer (Unix) Android BlackBerry
Record camera X X X X
Record audio Fallback to audio backend Fallback to audio backend Fallback to audio backend X X Fallback to audio backend
MetaData writer X
Audio encoder settings X X X
Video encoder settings X X X
Container settings X X

Supported audio decoding features by backend

DirectShow (Windows) Media Foundation (Windows) AV Foundation (Mac OS / iOS) GStreamer (Unix) Android BlackBerry
Decode audio X X

Audio plugins

Audio backends implement QAudioInput, QAudioOutput, QAudioDeviceInfo and QSoundEffect

Here is the list of the current audio backends:

  • Windows Multimedia
  • CoreAudio (Mac OS / iOS)
  • PulseAudio (Unix)
  • Alsa (Unix)
  • OpenSL ES (Android)
  • QNX

PlaylistFormat plugins