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Altera_Forum
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17 years ago

Howto mix two CVBS Video streams?

Hi, I'm planning to do a Picture-In-Picture application using 2 Video ADC and a Cyclone FPGA with some SDRAM attached.

I know how in principle stuff is digitized, sync codes extracted and colorspace converted so that one can store a frame in the external SDRAM.

I'm not shure how to syncronize two video streams, because the framerates will have a slow drift because the 2 cameras attached are free running and not synchronized.

So once a while I have to drop a frame when e.g. CAM1 "overtakes" CAM2, do I?

Is the mixing normally done on a line base or is it better to do it frame by frame?

How do I resize a picture?

Does anyone have good literature about scaling algorithms and / or video processing in general?

Markus

1 Reply

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

    Past analog video systems always used a central sync supplied to each camera. With digital video, frame buffering may be used instead. Image scaling is applied to full frames anyway.

    Altera, by the way, has a collection of Megafunctions for digital image processing, e. g. a scaler.