Trying to play a video .... such a problem

OlivierH

Hi everybody !

I'm trying to make a QML plugin which can play a video. So I tryed some things :

using Multimedia Toolkit : but I am under Windows OS (XP for developping and 7 for the execution)
using Qt5.0 (great job guys ;)) on 7 looks great, but it still don't work on XP. Moreover QtQuick 2.0 have change the OpenGL version ... it can't work with my app ...
using Phonon : it's a good widget, but when I add OpenGL, perfs are soooo bad ....
using QMovie : I can't open a video file format :| just images are supported ....

So ...

Does anybody has the same problem or a resolution of this one (like the creation of a plugin ....) ?

Thank you guys !

sierdzio

You don't have to create anything. MultimediaPlayer, Audio and Video are the things ("link":http://doc-snapshot.qt-project.org/5.0-newdocs/qtmultimedia/qml-multimedia.html).

OlivierH

In fact, I have already try QT5.0 with QtQuick 2.0 .... but it isn't compatible with my app : I really need to use OpenGL as it was in the last version ...

Moreover : this doesn't work on my Win XP ....

mrcdrc

I have done this recently based on Qt4.8/QtQuick1 using the VLC libraries (QtMediaHub was a good guidance on how to do this). Note that a VLC installation on Windows already contains the required VLC-Sdk. For me this works flawlessly on an XP machine. You can take a look at my code here: https://www.dropbox.com/s/djf3bav7ftcoa26/MediaPlayer.tar.gz This is of course work in progress...

I tried to mimic the behavior of the MediaPlayer and VideoOutput components that are provided by QtQuick2.

If you're buidling on a Windows machine don't forget to setup the paths to the VLC-Sdk in the MediaPlayer.pro file. On Linux you propably will have to install the vlc sdk separately.

mrc

OlivierH

Thank you so much mrcdrc ! This works quite well ... But I still face some problems ....

First, the video output has to be the last thing that my QML file draw otherelse my video won't be played (qml error message : main vout display error: Failed to set on top.).

Then, if I try to insert an Image object, my video don't play anymore ... Like a non-managed exception in qmlviewer, my app close and this qml error message : main vout display error: Failed to set on top.

Have you ever face this bug ? And do you have any lead to resolve this problem ?

Thank you folks !
Olivier

mrcdrc

Actually, the error message "main vout display error: Failed to set on top" is related to vlc. When i noticed it first, i googled a bit and found people stating that it can safely be ignored...
Are you using QGLWidget as i proposed in the provided example code? I meanwhile changed this to be conditionally invoked only if at least OpenGL 2.1 is present, i otherwise experienced significant performance hits on an older XP machine.

I did something like:

@
if(QGLFormat::openGLVersionFlags() & QGLFormat::OpenGL_Version_2_1) {
QGLWidget *glw = new QGLWidget;
viewer.setViewport(glw);
}
@

So far i wasn't able to reproduce your problem when placing an 'Image {...}' on top - it shows up as expected while video is playing...

Maybe you can provide a stripped down code snipped to see if i can reproduce the problem (and possibly fix it).

Cheers
mrc

OlivierH

Ok, well I made a C++ plugin which use your abstractmediaplayer, videooutput, videopresenter and your videoplayer. This plugin is a DLL file which expose my VideoPlayer and VideoOutput types.

Then, I made a Main.qml which contains @Rectangle
{
id:root
width:1024
height:768
VideoPlayer{
id: player
source: "D:/Aspen.avi"
autoPlay: true
function togglePlayback() {
if(!player.playing) {
player.play()
}else if(!player.paused)
player.pause()
else
player.resume()
}
}

Rectangle{
    id:snd
    width:root.width*2/3
    height: root.height
    x:root.width/3
    color:"green"
}
Rectangle{
    id:charts
    width:root.width/3
    height:root.height/2
    y:root.height/2
    Image{
        width: parent.width
        height: parent.height
        fillMode: Image.PreserveAspectFit
        source: "img/toto.png"
    }
}

Rectangle{
    width:root.width/3
    height:root.height/2
    color:"black"

    VideoOutput {
        id: videoOutput
        source: player
        anchors.fill: parent
        fillMode: VideoOutput.PreserveAspectFit
        smooth: true
    }
}

}@

This main imports the VideoOutput & VideoPlayer with a qmldir. When I load an Image, my VS Just in Time debogger is warning me and asks me if I want to debug my app .... But I don't know why... When I delete the Image tag, my Video runs as I want...

Thank you !
Oliv

OlivierH

Hey guys ! I don't know what happend but my plugin works quite well ! I just add some QDebug (I think that I previously have a compilation bug ...) and now my video is playing quite well !!

Thank you so much !

mrcdrc

Hey Oliv,

this is great news!

I meanwhile tried your Main.qml example with my non-plugin based code and it worked as expected. No matter were i place the VideoOutput element, with or without the Image element - makes no difference. So it really might be compiler related (my builds are all based on gcc - linux&win32).

Cheers
mrc

OlivierH

Erf, actually, I have a bad news...

The video works... but just when my computer want it... So I can't tell what is my new bug... I will try to find an explanation or something...

Thank you guys !