I want to display video and show its frames to the gui. I have a processor that pumps out packed RGB data, and to display them, I have a QImage that took in the data and convert them to QPixmap for display. However the QImage to QPixmap conversion is too slow for real time play speed. It played fine when the videos are around 1080p, but with 4K video, the fps just plummeted. QImage frame_image(data, width, height, QImage::Format_ARGB32); QPixmap frame_pixmap = QPixmap::fromImage(frame_image); What is a faster way to do this?

Do you update your image from a different thread? If so you should learn about threading: Threading Basics

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QImage to Qpixmap conversion is too slow

Unsolved General and Desktop

21 Posts 4 Posters 6.6k Views 3 Watching

L lansing
@mrjj

Hi, I have set the image to one in my resource folder for testing, now it has crashed at line m_frameImage = image. I have changed the image argument from const QImage & to QImage*, I don't know if that have a effect on it. But in debug, it did show my image dimension.
```
QImage *img= new QImage(":/cross.png");
myGLPainter->drawImage(img);
```
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SGaist
Lifetime Qt Champion
wrote on last edited by

#21

@lansing said in QImage to Qpixmap conversion is too slow:

QImage *img= new QImage(":/cross.png");
myGLPainter->drawImage(img);

That's the wrong thing to do as you will leak images doing so.

Beside the initialization issue pointed by @Christian-Ehrlicher can you provide the stack trace of your crash ?
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