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Details

Type: Bug
Resolution: Fixed
Priority: P2: Important
Fix Version/s: None
Affects Version/s: 6.5.0, 6.6.0, 6.7, 6.8
Component/s: Multimedia
Labels:
- FFmpeg
Environment:
Windows 10.0.19044 Build 19044
Lenovo Thinkpad E530
NVIDIA GeForce GT 635M - Intel HD Graphics 4000

Platform/s:

Windows
Epic Link:
OKR - Easy FFmpeg
Commits:
30eb2b241 (dev), b63e9a465 (6.7), fec0682bc (tqtc/lts-6.5)

Description

the requirement is saving a frame of QML media player.
I reported this problem here before but I have some updates and clarifications so decided to make a new one.

first of all there isn't "QOpenGLContext current in a different thread" anymore, But there are kinda tow new error:

damaged.mp4

failed to get textures for frame true
D3D11: Removing Device.
Failed to map readback staging texture: COM error 0x887a0005: The GPU device instance has been suspended. Use GetDeviceRemovedReason to determine the appropriate action.

crash.mp4

qt.multimedia.ffmpeg.mediadataholder: AVStream duration -9223372036854775808 is invalid. Taking it from the metadata
qt.multimedia.ffmpeg.mediadataholder: AVStream duration -9223372036854775808 is invalid. Taking it from the metadata
D3D11: Removing Device.
Failed to map readback staging texture: COM error 0x887a0005: The GPU device instance has been suspended. Use GetDeviceRemovedReason to determine the appropriate action.

I found out this bug directly depends on what media is playing, so I attached 3 video files with full code of the sample application to be reproduceable :

good.mp4 : there isn't any problem
crash.mp4 : app crashes and saved frame is damaged
damaged.mp4 : app not crash but saved frame is damaged

helper.h

class Helper : public QObject
{
    Q_OBJECT
    QML_ELEMENT
public:
    explicit Helper(QObject *parent = nullptr);
    Q_INVOKABLE void setVideoSink(QObject *videoOutput);
    Q_INVOKABLE void saveCurrentFrame();
private:
    QVideoSink *m_sink = nullptr;
};

helper.cpp

 
void Helper::setVideoSink(QObject *videoOutput){
    m_sink = qvariant_cast<QVideoSink*>(videoOutput->property("videoSink"));
}
void Helper::saveCurrentFrame(){
    m_sink->videoFrame().toImage().save("frame.png");
}

Main.qml
**

Button {
    text: "save frame"
    onClicked: {
        helper.saveCurrentFrame()
     }
 }

MediaPlayer {
        id: player
        audioOutput: AudioOutput {}
        videoOutput: videoOutput        onMediaStatusChanged: {
            if (player.mediaStatus === MediaPlayer.BufferedMedia) {
                helper.setVideoSink(videoOutput)
            }
        }
 }