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Altera_Forum's avatar
Altera_Forum
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14 years ago

Alpha VIP mixer overlay HEIGHT

hi,

I'm using the alpha blending mixer (alpha channels are not used), with 640x480 as the background layer.

In addition, 2 overlay channels are used, making it totally 3 layers being mixed.

The 2 overlay channels are made to fit whitin the borders of the 640x480 background layer as they are scaled prior to being feed to the mixer.

overlay 1 : CVI -> FRAMEBUFFER -> SCALER -> MIXER

overlay 2 : TPG -> CLIPPER -> SCALER -> MIXER

I'm able to clock the 640x480 mixer output to an output screen.

The problem occurs when I try scaling the HEIGHT of the 2 overlay layers. It looks like I'm not able to scale the HEIGHT to more than approx 225 for the overlays when they are displayed on the output screen. What I need to do is to scale the overlay HEIGHT's to fit within the 480 height of the background layer. If anyone can give me some pointers it would be appreciated.

1 Reply

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

    hi again,

    I solved the problem.

    In SOPC when activating run-time control of image size for the scaler, the input and output max size is determined from the parameters provided. In this case the "Output image height" parameter was set to 240, when changing this to 480 I was able to change the image HEIGHT to 480 at run-time.