Thomas Leong Posted March 9, 2015 Report Share Posted March 9, 2015 Instead of furthering the question of latency from the Decklink Duo inadvertently diverted within another discussion ( http://forum.dataton.com/topic/1617-blackmagic-decklink-duo-problems/ ) thought it would be better to start a fresh one here. Recently, I used the Decklink Duo and noticed no latency between the live IMAG video and the stage mics on the LED panels used. To date, I have not received a reply from the audio guy as to whether any audio delay was used. Personally, I doubt if audio delay was applied since - 1. It is not usual in my country for the audio desk to be so equipped unless specifically asked for BEFORE equipment is brought to the venue, and in this case, the venue was about 1 hour away from the city up in a mountain casino resort; and 2. As I was only present as a consultant to Watchout, any latency involving Watchout's use would have been referred to me to solve as the operator/user is new to Watchout, and no such questions were raised during rehearsals and showtime (by final client, the event organizer, nor anyone else). Here are the installation facts: Watchout Production PC: Mac laptop running Bootcamp; no live video feed; used built-in webcam as guide. Watchout Display PC: ASRock Z97 Extreme6 motherboard, i7 4770K at 4.2GHz, 16GB 1600MHz RAM, ASUS HD7970 Matrix Platinum graphics card with 4 of the Display Ports used to output to the LED's Processor-Sending Card. HD7970 occupied the first x16 slot; Decklink Duo occupied the second x16 slot, but since this was a Z97 + 4770K, the 16 available PCIe 3.0 lanes were re-distributed to x8/x8 for both slots. Live Video: Decklink Duo with only 1 input used, fed by a DataVideo mixer via a 100m cable (3 Sony cameras to mixer) Result: I did not see any latency. Neither did the Watchout operator when I pointed out that there was no latency, and he concurred. Question: Could it be that, in our case above, because the Decklink Duo was installed in a slot with lanes direct from the cpu rather than from the PCH, there is significantly less latency than should be expected, to the extent that the human eye cannot detect the latency, if any. I do not have a SDI camera to test. If someone who has, can test and report back, it would be appreciated. Try a PCIe 3.0 slot that has lanes direct from the cpu rather than from the PCH (Platform Controller Hub; a'ka Z87, Z97, X79 or X99). Thomas Leong Quote Link to comment Share on other sites More sharing options...
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