[Development] The dark side of QtMultimedia

Holger Hans Peter Freyther holger at freyther.de
Mon Nov 10 09:43:25 CET 2014

On Sun, Nov 09, 2014 at 11:09:37PM +0100, Kevin Kofler wrote:
> Nichols Andy wrote:

> How is QtMultimedia "essential" when there had been a working alternative 
> (Phonon) even before QtMultimedia was started? In fact, Phonon used to be 
> hailed as the showcase for perfect collaboration between Qt and KDE, and 
> even shipped with Qt, until Nokia decided to reinvent the wheel. (At that 
> point, the bundled copy of Phonon in Qt 4 ceased being updated and was 
> arbitrarily "deprecated", while the Phonon project moved on.)

tossing my two cents. Multimedia is hard. I sat three days at a
korean company trying to figure out why Qt Phonon wouldn't play
a MP3. In the end I was asked to stop debugging but the issues

* Phonon making certain assumptions on GStreamer
* GStreamer making certain assumptions on its plugins
* HW Vendor not caring about any assumption when creating/
providing plugins.

The issue is that neither GStreamer nor Phonon verified its'
assumptions. This means if something goes wrong... you will
debug for a long time (abstractions for an abstraction, etc).
At the same time "gst-launch playbin(2) .." just worked.

Multimedia is hard and creating an abstraction is a nice goal
but the details and fall-out can be horrible (just like in my
Phonon example and QtMultimedia in this threads experience).

Now really getting to my two cents. Instead of wrapping API
Qt should make sure the framework can be integrated. E.g. in
terms of GStreamer provide plugins that allows to easily embed
video into Qt applications but ask users to use the "native"
API to manage the pipeline/playback.

kind regards

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