Thursday, August 15, 2013

A Sample to Use for Debugging and Testing Performance of the QtMultimedia Backend

In the github project for PiOmxTextures I recently uploaded also a sample player (tools/POCPlayer) that can be used for debugging and testing the performance. This is supposed to be a sample for the performance of the QtMultimedia backend and Qt itself on the Pi. It is entirely Qt/QML based, with the GUI written entirely in QML/Javascript. It shows the common controls for a media player and the service for metadata extraction. This is a demo of the current state:

How to Build

This is simple: it is a standard Qt application, with C++/Qt and QML code. A simple build of Qt version >= 5.1 should be sufficient. There is no interaction whatsoever with the plugin during build time.


The current version can handle images and videos. Unfortunately it seems to perform pretty good in 1080p with 720p video, but 1080p videos are quite difficult to handle when other animations are running concurrently. Animations not involving video perform really good.
What you see in the video is running on the eglfs plugin: running on some more interesting layers like Wayland would require some changes in how EGL images are handled in the QtMultimedia plugin and PiOmxTextures. Unfortunately, it seems the QtWayland module is not currently perfectly working, so a hard work might be needed.

Thursday, August 8, 2013

Raspberry Pi Wheezy Image With OpenMAX-based Multimedia Backend

Please take into consideration that this firmware is based on an old firmware and an old PiOmxTextures version.

As I see still someone has troubles building PiOmxTextures, I built a new image based on the Raspbian wheezy image released the 26th of July ( This version of the image also contains Qt version 5.1.2 (35fe76d9c343f98ec55c7cacd8c402e90d91ef38) and an OpenMAX-based Qt Multimedia plugin (PiOmxTextures). The available Qt modules are:
  • qtbase
  • qtscript
  • qtxmlpatterns
  • qtjsbackend
  • qtdeclarative
  • qtsensors
  • qtquick1
  • qtgraphicaleffects
  • qtwebkit
  • qtwayland
  • qtsvg
  • qtserialport
  • qttolls
  • qttranslations
  • qtquickcontrols
  • qtmultimedia
  • qtimageformats
The mediaservice plugin installed is the openmaxil plugin (available here: It is based on ffmpeg version 2.0 and that version of ffmpeg is statically built inside the PiOmxTextures library available in /usr/lib.
Note that the wayland module and the wayland and xkbcommon libs are available in the image, but I never tested those. Also, PiOmxTextures won't work with wayland but only using the eglfs platform plugin.

How to Test

Of course all this is experimental and if you seriously intend to use in production I suggest you start working on the sources in I placed a build of the POCPlayer (sources are available in the same repository under tools/POCPlayer) in the home directory of the pi user. You can run it and see how it works:

./POCPlayer [video_file]

By pressing the "l" button, you can see the possible options. The POC player is experimental as well and it is entirely implemented in QML.
You can help improve and fix both PiOmxTextures lib and the openmaxil plugin by simply replacing libPiOmxTextures in /usr/lib and/or in /usr/local/Qt-rasp-5.1.2/plugins/mediaservice.

How to Use

Refer to Raspberry Pi Wheezy Image With Qt and Wayland Support for instructions on how to use. The procedure is almost identical. Then, you can simply build your QtMultimedia-based application and test.

Where to Download

Unfortunately the download is over 1GB. You'll have to download from this ed2k link. You can download it with this excellent torrent. Thanks to the author.

Please let me know if you experience troubles downloading or with the image itself. Bye!