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MLaur2's avatar
MLaur2
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8 years ago

Do "Scaler II (4K ready)" in general have a problem with downscaling more than a factor 4?

I have a video application, designed in Qsys v. 16.1.

Had some issues with the "Scaler II (4K ready)". During debug, I have cut away everything else, thus my Qsys design now consists of: Test pattern generator -> Scaler II (Dout is exported for analysis)

Test pattern generator is currently configured as 704x576 pix, RGB, colour bars.

The scaler is currently configured over control-interface to downscale to 176x144.

With this configuration, I get the attached uncompressed image.

In horizontal direction I can downscale 4 times, but anything below 240pix vertical dimension, corrupts the image.

This project was originally built in Quartus 13, sp1, using scaler v. 13.0.1

In that project I could scale to 176x144 without any problems.

Best Regards

Magnus Lauritsen

JT electric

1 Reply

  • MLaur2's avatar
    MLaur2
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    8 years ago

    Hi again,

    I just figured it out.

    The down scaled image requires more buffering. I guess this is due to reduced pixel-frequency by the horizontal downscale-factor.

    My first solution was to insert a frame-buffer after scaling.