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This one is just a question about output latency, we have just built up a vMix box with a black magic quad 2 and a GTX1060 and have been seeing how things work with output.
I know that the FAQ mentions 2-3fps of normal vmix latency but is there any additional latency added depending on the output chosen?
Is there likely to be less latency from the SDI output on the BM card as an external output vs as a second full screen on the GPU or vice versa?
Cheers
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Hello mcollege and welcome to the Forum! External output (except NDI), that is using an external card with output capabilities like the BM Quad 2 always implies relatively long latency. The reason is that the video has to be rendered by the card. In practise this means hardly usable for IMAG. Fullscreen output (from the GPU card) is the fastest, but is limited to 2 outputs (actually 1 for editions below 4K). As the FAQ also mentions the output resolution should match the projector/monitor to minimize latency. There is also a Settings/Performance options for "Low latency", but make sure to read the Help file about the requirements. Good luck!
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I've been curious if anyone has had the chance to test the latency of a Blackmagic card vs. something like an AJA, Magewell, etc ?
The best I've been able to get is about 7 frames from SDI in to SDI out on Blackmagic Decklink Quad 2. And about 4 frames for GPU output.
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At 26:44 Tim stated that AJA was best, then Magewell then BMD but there's probably only a frame in it. I have tested BMD SDI to SDI with a timecode display and get about 6.5 frames.
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bcvideo wrote:The best I've been able to get is about 7 frames from SDI in to SDI out on Blackmagic Decklink Quad 2. And about 4 frames for GPU output. So, just to be clear. You measured from the Quad's input to the output used as an External in vMix (i.e. not just pass-through in the Quad)?
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richardgatarski wrote:bcvideo wrote:The best I've been able to get is about 7 frames from SDI in to SDI out on Blackmagic Decklink Quad 2. And about 4 frames for GPU output. So, just to be clear. You measured from the Quad's input to the output used as an External in vMix (i.e. not just pass-through in the Quad)? Exactly. Camera into an SDI In on the BMD Quad as source in Vmix, External Output to an SDI output on the same BMD Quad... hovering around 7 frames of latency.
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