[Interest] Phonon video
Bo Thorsen
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.
--
Expert Qt and C++ developer for hire
Contact me if you need expert Qt help
http://www.fioniasoftware.dk
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Jason H
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.
R. Reucher
Phonon is highly dependent on the back-end and in case of the video-player, especially on the quality of the available codecs... on Windows, I've had best results with the codecs from
http://www.windows7codecs.com/
I can assure you that Phonon still works this week :). But surely, Windows updates can ruin your live... and it's not a problem of Qt / Phonon.
HTH, René
Bo Thorsen
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.
Bo.
Jason H
And I'd love to see your filter graph.
Bill Crocker
> I hate to ask this, but have you rebooted?
>
Along that vein. There is a great sitcom called "The IT Crowd"
that came out of Great Britain. You can find it on Netflix.
The line "Have you tried turning it off and on." is used
constantly. Must see.
Bill
_______________________________________________
Joseph Crowell
surprising that Windows Media player will play them though. Windows
media Player might be the culprit that broke your codecs.
R. Reucher
On Thursday 29 March 2012 15:57:05 R. Reucher wrote:
> Phonon is highly dependent on the back-end and in case of the video-player,
> especially on the quality of the available codecs... on Windows, I've had
> best results with the codecs from
>
> http://www.windows7codecs.com/
>
> I can assure you that Phonon still works this week :). But surely, Windows
> updates can ruin your live... and it's not a problem of Qt / Phonon.
I've now had a chance to try this on an "up to date" Windows 7 x64 installation with said codecs, and the Phonon video player still works nicely here (watching different YouTube video streams in my test, MP4 & FLV).
HTH, René