Phonon + custom media source

**wysota** · 8th July 2008, 21:44

It is very easy to use Phonon to play a movie from a file or over network. But is it possible at the current state or is it planned in a near future to provide a custom media source, for instance generate video frames directly in the application?

A side question is the exact opposite of the previous one - is it possible to provide a custom sink for the media? For instance if I wanted to access each frame of the video and save it to disk as a separate image without showing the video on screen? In theory one could create a custom Effect that would act as a filter, do some work and then pass through the media to the next node, but there are two problems:
1. this would require to have some final sink (hence show the video)
2. I don't think at present one can implement a custom effect

So is Phonon going to be a framework for just viewing existing media in a platform independent way or do/will we have an interface to create/modify/operate on the media that could be used in yet undetermined usecases? Do you Jeff or anyone else have some knowledge (or any comments) about that?

**JimDaniel** · 10th July 2008, 07:26

I would be very interested in knowing this too.

**glebovitz** · 18th July 2008, 18:41

Here is what I know so far. Phonon is a platform independent wrapper around the
platform specific media library. Therefore, implementing different
sources and sinks must be implemented in the media libraries themselves. If you want to create a new media source, your either need to build a phonon back-end for your video generator or add a new source to the underlying media library. At the moment, there appears to be no way to capture frames or inject them into the video widget.

From what I have read, there is some discussion about future releases of the API providing a mechanism for introducing effect call-outs into the media stream processing. This will allow a, for instance, a developer to insert overlays on a video image. Phonon is a contributed third party library for Qt, so it is probably best to follow the phonon discussions at KDE to understand future plans.