Raspberry pi-4. Issues with video, Media player example crashes and freezes when loading and playing videos.

[Thomas Pearson]

Im trying to use the MediaPlayer in QML to play a video for my application, i noticed some issues with it and found the same issues were present in the QML examples that also used the MediaPlayer

When running the "Media player" example app from QT-creator's library of example applications, on a raspberry pi 4, connected to a 1080 by 1080 p monitor, the video will run fine the first time, then when reloaded to view again, will start to stutter and stop till eventually it freezes. Once this occurs, usually “Internal data stream error” occasionally flashes to the screen. Whilst the console prints “warning: a lot of buffers are being dropped” Furthermore it completely crashes when trying to load a 6 MB video.

I Have been able to replicate this issue on two separate R-pi4's with two separate copy's of bootToQt

So far in an attempt to debug this i have added a heat-sink to the R-PI4 , which has kept its temps at a stable 40c. I have changed the "QT_MEDIA_BACKEND" environment variable to several different settings , but am unsure if there is a specific one for R-PI which i haven't tried. I have reduced the memory size of the input video to 1.3mb , and have been using a 640 pixel by 360 pixel video. i reduced the size of the output display window for the video to a variety of sizes, even 100 pixels by 100 pixels.

if you would like to replicate the issue:
Here is an example of the video : https://videos.pexels.com/video-files/855401/855401-sd_640_360_25fps.mp4
though the error also occurs with the video that comes with the example application.
I am using Boot to QT 6.7.0 and replicated the same issue with 6.8.0
Code can be found in the qt-creator example named "Media Player"
it can take a few re-loads of the video to cause the error.

[Thomas Pearson]

reported the issue to qt support , its now a bug which they are working on: https://bugreports.qt.io/browse/QTBUG-125292
incase anyone else has the same issue, i have a work around fix:
construct a timer and a loader. use the timer to delete the media player every time the video finished playing and reconstruct it with the loader.

import QtMultimedia

Item {

/// the below is written as a work around for a bug with the multimedia player on raspberry pi's.
/// i belive some kind of memory leak in the media player forms when the media player compiles for the r-pi.
/// this causes the media player to slow down with each iteration fo the video loop
/// as such , this code deletes the video player and constructs a new video player between each loop.
    id: root
    property point beginDrag
    property var source
    property bool hotReload
    Component
    {
        id: mediaPlayerContainer

        MediaPlayer
        {
            Component.onCompleted:{ console.log("Player loaded"); play()}
            Component.onDestruction: {console.log("Destruction Beginning!")}
            id: mediaPlayer
            videoOutput: vidya
            loops: MediaPlayer.Infinite
            source: root.source
           }
    }
    Timer
    {
         id: timer
         interval: 1000
         property int counter: 100
         repeat: true
         triggeredOnStart: true
         onTriggered:
         {
            counter += 1
            //console.log(counter)
            if(counter > 55)
            {
                counter = 0
                //console.log("hotReaload");
                hotReload = true
            }
            else
                hotReload = false
        }
        Component.onCompleted:{ timer.start()}
    }
    VideoOutput {
        id: vidya

        anchors.fill: root
    }
    Loader
    {
        id:videoloader
        active: !hotReload
            sourceComponent: mediaPlayerContainer
    }

    Component.onCompleted: {console.log("ITEM LOADED");Loader.active=true; timer.start() }
}

[jsulm]

@Thomas-Pearson said in Raspberry pi-4. Issues with video, Media player example crashes and freezes when loading and playing videos.:

I am using Boot to QT 6.7.0

Since Boot2Qt is a commercial product you can also ask QtCompany directly for support if you can't find help here.

[Thomas Pearson]

reported the issue to qt support , its now a bug which they are working on: https://bugreports.qt.io/browse/QTBUG-125292
incase anyone else has the same issue, i have a work around fix:
construct a timer and a loader. use the timer to delete the media player every time the video finished playing and reconstruct it with the loader.

import QtMultimedia

Item {

/// the below is written as a work around for a bug with the multimedia player on raspberry pi's.
/// i belive some kind of memory leak in the media player forms when the media player compiles for the r-pi.
/// this causes the media player to slow down with each iteration fo the video loop
/// as such , this code deletes the video player and constructs a new video player between each loop.
    id: root
    property point beginDrag
    property var source
    property bool hotReload
    Component
    {
        id: mediaPlayerContainer

        MediaPlayer
        {
            Component.onCompleted:{ console.log("Player loaded"); play()}
            Component.onDestruction: {console.log("Destruction Beginning!")}
            id: mediaPlayer
            videoOutput: vidya
            loops: MediaPlayer.Infinite
            source: root.source
           }
    }
    Timer
    {
         id: timer
         interval: 1000
         property int counter: 100
         repeat: true
         triggeredOnStart: true
         onTriggered:
         {
            counter += 1
            //console.log(counter)
            if(counter > 55)
            {
                counter = 0
                //console.log("hotReaload");
                hotReload = true
            }
            else
                hotReload = false
        }
        Component.onCompleted:{ timer.start()}
    }
    VideoOutput {
        id: vidya

        anchors.fill: root
    }
    Loader
    {
        id:videoloader
        active: !hotReload
            sourceComponent: mediaPlayerContainer
    }

    Component.onCompleted: {console.log("ITEM LOADED");Loader.active=true; timer.start() }
}