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Altera_Forum's avatar
Altera_Forum
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17 years ago

How to use Alpha Blending Mixer

Has anyone used the Alpha Blending Mixer with Alpha Blending turned on ?

I'm not too sure how to use it or what results to expect. I thought I'd have a play by just mixing two images 50:50, but realised that I don't really understand the mixer sufficiently. I just want a simple fixed uniform blend across the whole image, but the blend signals are per-pixel Avalon ST.

What would be the best way for me to generate fixed blend signals presented as Avalon ST sources ? Presumably they would have to be synchronised with the source video ?

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    Have you tried the app. note no.427?

    I am trying to use it but there are some tasks with higher priority to deal....

    Good luck
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    If you want to do a fixed blend just tie the Alpha input ports for the two video feeds to some hard value. The Alpha Blending mixer assumes that the input on the Alpha port is presented on a per pixel basis and that it coincides with the avalon streaming input. It won't know or care if you just set it to some value.

    Jake
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    Thanks, sounds encouraging. But how do I go about creating an AvalonST component for SOPC ? I've searched high and low and found loads of stuff on how to generate Avalon Masters and Avalon Slaves, but have found nothing on how to generate AvalonST components. I have the specs for Avalon and the Component Builder, which are useful, but no substitute for an actual coded example.