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Video delay when using effect overlay

Feb 04 (9 months ago)
Joe wrote
I would like to overlay text on a live SDI video input and then output the processed video to SDI with minimal amount of delay. I am using a Blackmagic Decklink card and the VB.NET SDK. This works fairly well but the delay is about 1 second when the effect is applied. The delay seems to start out at just a few frames which is fine but then it increases over time to about a second. Does anyone have a recommendation for reducing the delay?
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6 Answers
Feb 04 (9 months ago)
Roman Minyaylov agent wrote
Hi

Text overlayed using default video effects API or some manual way?
How many text effects applied?
Feb 05 (9 months ago)
Joe wrote
Hello, I am using the default "VFVideoEffectTextLogo" to create the effect and "Video_Effects_Add" to apply the effect. I am then updating the effecting once a second using "Update."

I am only applying one effect and then updating it.

Thanks
Feb 07 (9 months ago)
Roman Minyaylov agent wrote
Feb 15 (9 months ago)
Joe wrote
I was able to get the processing delay down to 5 frames by only updating 2 of the effect parameters each second rather than all of the parameters that didn't need updated each time.

Is it possible to take advantage of the Decklink internal keyer to overlay text? I would like to loop the live video through the Decklink and simply apply the overly using the internal keyer.

Thanks,
Joe
Feb 15 (9 months ago)
Roman Minyaylov agent wrote
Please send logs - https://support.visioforge.com/041973-How-to-send-debug-info

With logs I'll be able to help you.

Which Blackmagic card do you have?
Feb 15 (9 months ago)
Joe wrote
I just sent the logs to the support email. I am using a Blackmagic Decklink 4k Extreme.