Using QT with DM6646 - Getting QT to use the attribute buffer

Aditya Gaddam

Hi,

I am working with a DM6446 EVM board. I have gotten a video feed over the composite input to show up on the screen along with QT drawing some GUI stuff. However, QT takes up the entire OSD layer and doesn't show any of the video through. I know the video is there because I've written to the attribute layer manually to clear an area and the video shows through there. Is there any way to make QT automatically update the attribute layer wherever there isn't any pixel data being written to the OSD layer? Right now, wherever I'd like it to be transparent, QT just shows a bright green.

One option I think I have is to read the buffer from the OSD layer and update the attribute layer to have a value of 0 wherever the OSD layer has a bright green... but I'd rather not have to do that manually.

Thanks,

Aditya

over 15 years ago

0 Paul.Yin over 15 years ago

TI__Genius 14405 points

Just FYI on what QT is: http://en.wikipedia.org/wiki/Qt_(framework)

0 Frank Walzer over 15 years ago

TI__Mastermind 44306 points

Aditya,

you don't give any specifics about your Qt version. However so far I have not seen any with a specific knowledge about the display hardware in Davinci. Qt just knows the framebuffer and writes there. The green dots are just the standard background.

But as you have access to Qt sources you could implement that yourself by digging into the Qt screen drivers. Just I have no idea how complex that is.

Regards

Processors

Processors forum

Using QT with DM6646 - Getting QT to use the attribute buffer