text over a video

aforizma

Hello everyone,

I have Imx6 Evaluation Kit. I have an embedded system which shows an analog video(the source is external). So I want to write a GUI over this video. How can i do it. Could you give an example tutorial or document?

J.Hilk

hi @aforizma
first question you'll have to answer, QWidget or QML ?

And yes, in both cases it should be relatively simply to show a text over a video.

aforizma

Qwidget. I want to continue show analog video and ı want to add GUI over this video. Unfortunately, this is my first qt adventure.

J.Hilk

@aforizma
ok, than you should look at the QMovie class.

I'haven used that myself jet, but I know that you can asign a QLabel a QMovie.
Than, depending on if it works or not, you can set a text to the QLabel via setText.
If that doesn't wokr like I asume it will, you'll have to eventuall subclass QMovie or QLabel and print the desiered tex yourself.

SGaist

Hi,

What are you using to grab that analog video ?

aforizma

@SGaist I don't know it. Actually, this is my problem. I have to grab video and then ı will show video and GUI together.

Pablo J. Rogina

@aforizma said in text over a video:

. I have an embedded system which shows an analog video(the source is external)

so you have a program (not written by you or that you can modify) running on your board that displays video?

I have to grab video and then ı will show video and GUI together.

You want the video to display in a Qt app and do some text overlay?

aforizma

@Pablo-J.-Rogina Yes ı have a program and when the board opens, LCD displays a video with GStreamer automatically. This video is analog video. when you connect a camera you will see it. Thus far, I didn't need qt and qt GUI. But now ı want to see symbology on video. So ı need a GUI. Also, ı built a GUI with QT. But When the GUI app runs, the video is not working on LCD. I see only GUI app. I think this problem is not about transparency. I didn't write any code about video on GUI. I am newbie QT and I don't know how can ı integrate video on QT.

Pablo J. Rogina

@aforizma said in text over a video:

LCD displays a video with GStreamer automatically

And what about text overlay plugin with GStreamer itself? Not that I've used myself, but an idea. No need to deal with Qt if that works...

I don't know how can ı integrate video on QT

As you stated QWidget before as your preference, maybe this camera example can be a starting point. The problem I see is how Qt backend will recognize your video source, especially if it's analog video...

aforizma

@Pablo-J.-Rogina said in text over a video:

As you stated QWidget before as your preference, maybe this camera example can be a starting point. The problem I see is how Qt backend will recognize your video source, especially if it's analog video...

Thanks for your quick reply. GStreamer isn't a solution. I need a GUI which is integrated GPIO. I use dev/fb0 when displays video on LCD. How can ı recognize my video source in QT?

Pablo J. Rogina

@aforizma said in text over a video:

I need a GUI which is integrated GPIO

could you please elaborate more on this? So you need to read GPIOs and then display symbols over video based on such values?

aforizma

@Pablo-J.-Rogina said in text over a video:

could you please elaborate more on this? So you need to read GPIOs and then display symbols over video based on such values?

Yes. That is true.

SGaist

Recent version of GStreamer should provide the qmlsink plugin. You could try to use that and write a QtQuick GUI with whatever you want to show.