[Interest] Phonon video

Jason H scorp1us at yahoo.com
Thu Mar 29 16:59:18 CEST 2012

I hate to ask this, but have you rebooted?

And I'd love to see your filter graph.

----- Original Message -----
From: Bo Thorsen <bo at fioniasoftware.dk>
To: Jason H <scorp1us at yahoo.com>
Cc: Qt Project MailingList <interest at qt-project.org>
Sent: Thursday, March 29, 2012 9:59 AM
Subject: Re: [Interest] Phonon video

Hi Jason,

Thanks for the attempt :)

As I say in the description, it worked last week, now it doesn't. So 
it's not a question of installing working codecs, because I didn't 
uninstall any of them.

Also, when I first tried to play the files we use, WMP wasn't able to 
play them, so Phonon wasn't either. Then I installed the codecs, and 
both were able to play them. Now, only WMP can play the files.

About the QtMultimedia: The detailed description of the module says "The 
functionality provided by the Phonon Module is on a higher level and in 
many cases more suitable for application developers."

But maybe I have to use it if Phonon is broken beyond reasonable repair.


Den 29-03-2012 15:48, Jason H skrev:
> I thought QtMultimediaKit was the way to go?
> I would suspect that something in the DS filter graph changed. Verify you have a valid path for the file type you are trying to play: http://msdn.microsoft.com/en-us/library/ms787460.aspx
> Keep in mind you still need to install video codecs because mingw version of Qt does not work with Windows7's new media interfaces. Installing K-Lite Codec pack usigally works for me.
> ----- Original Message -----
> From: Bo Thorsen<bo at fioniasoftware.dk>
> To: Qt Project MailingList<interest at qt-project.org>
> Cc:
> Sent: Thursday, March 29, 2012 8:34 AM
> Subject: [Interest] Phonon video
> Hi people,
> I've been trying to figure out why phonon suddenly doesn't work anymore.
> It plays audio just fine but not video. I'm completely stuck.
> I built and ran the qmediaplayer demo and saw the same thing, so it's
> not my code. And the same code plays the files just fine on Linux. But
> just for reference, here it is anyway:
>       mPlayer = new Phonon::MediaObject(this);
>       mVideo = new Phonon::VideoWidget;
>       Phonon::createPath(mPlayer, mVideo);
>       if (!mPlayer->hasVideo()) {
>           qDebug()<<  "Phonon video sink is not available";
>           ...
>       }
> hasVideo() returns false, and any attempt at adding a video file to
> Phonon gives me a "Pause Called" in the debug output window. This is the
> code used to play a file:
>       mVideo->show();
>       mVideo->resize(200, 200);
>       mPlayer->enqueue(Phonon::MediaSource(filename));
>       mPlayer->play();
> Calling Phonon::BackendCapabilities::availableMimeTypes() gives me a
> list of 54 mimetypes with both audio and video types in it. The files
> I'm trying to play are supported, and Windows Media Player plays them
> just fine.
> Now here's the really strange part: Last week it worked. But suddenly,
> video playback is gone. I have no clue what happened in between. I might
> have updated Windows, but if that breaks Phonon, we have a real problem.
> I can see that the DS94 backend is still there in both my 4.8.0 and
> 4.7.4 plugins.
> This really worries me. The code is for a customer with an embedded
> system that's going to be deployed on machines in many countries.
> Calling those back to fix a Phonon problem *is not* an option. If Phonon
> can't deliver a stable environment (and I currently seriously doubt
> this), I will have to ditch it.
> I obviously tried to search the net for this, and found plenty of people
> with the same result. But none with a solution for it. I hope someone
> here can help.
> I'm on Windows 7 x64 and Windows XP 32 bit, using a fully updated SDK
> 2.4.1 with both visual studio 8 and mingw compilers and Qt versions
> 4.8.0 and 4.7.4.
> Bo Thorsen,
> Fionia Software.

Bo Thorsen,
Fionia Software.


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