I've had a good look through the forums here, Reddit as well but so far have not found a solution to this.
I am using OBS with a Blackmagic Duo 2 SDI card, using outputs only using the Decklink support built in to OBS. We are not streaming or recording within OBS, only using the Decklink output. Our sources are normally all browser sources, but for the purposes of testing this issue I have been using a local sync test pattern as a media source on loop which is a download from this Youtube video: https://www.youtube.com/watch?v=bCPEidaVzQU
We are normally using four separate instances of OBS, all running from their own directories in portable mode, however, if I run one instance, the issue is still present. We are encountering audio drift if we leave this sync test pattern (or our normal sources) running, if we leave it running over a period of 12 hours then there are 10 or more frames of audio delay on the outputs(measured by playing back frame by frame on an EVS). We see the following sort of line in the log and the delay does seem to correspond to these values:
Most of the results I have found when searching for this issue refer to hardware overutilisation. Running Task manager we never see the CPU or GPU go higher than 50%, there is plenty of RAM spare etc so this does not appear as we see it to be the case but happy to accept suggestions to the contrary. If there was a constant number of frames delay we could deal with that but the drift is an issue. The amount of drift is arbitrary and I have been able to replicate this behaviour on a second identical machine.
I've attached a log file taken today from one of the OBS instances where there's a few lines shown, I have the instances running overnight as a fresh soak test with the only difference being that they are running with administrative rights as I found a suggestion that this can help with GPU access. This is running a fresh release of OBS from Github but we have experienced the same issue with the current release as well, hence trying a more up to date build to see if it made any difference.
Just wondering if anyone has encountered the same, or can offer any suggestions?
I am using OBS with a Blackmagic Duo 2 SDI card, using outputs only using the Decklink support built in to OBS. We are not streaming or recording within OBS, only using the Decklink output. Our sources are normally all browser sources, but for the purposes of testing this issue I have been using a local sync test pattern as a media source on loop which is a download from this Youtube video: https://www.youtube.com/watch?v=bCPEidaVzQU
We are normally using four separate instances of OBS, all running from their own directories in portable mode, however, if I run one instance, the issue is still present. We are encountering audio drift if we leave this sync test pattern (or our normal sources) running, if we leave it running over a period of 12 hours then there are 10 or more frames of audio delay on the outputs(measured by playing back frame by frame on an EVS). We see the following sort of line in the log and the delay does seem to correspond to these values:
13:25:54.566: adding 21 milliseconds of audio buffering, total audio buffering is now 21 milliseconds (source: Media Source)
Most of the results I have found when searching for this issue refer to hardware overutilisation. Running Task manager we never see the CPU or GPU go higher than 50%, there is plenty of RAM spare etc so this does not appear as we see it to be the case but happy to accept suggestions to the contrary. If there was a constant number of frames delay we could deal with that but the drift is an issue. The amount of drift is arbitrary and I have been able to replicate this behaviour on a second identical machine.
I've attached a log file taken today from one of the OBS instances where there's a few lines shown, I have the instances running overnight as a fresh soak test with the only difference being that they are running with administrative rights as I found a suggestion that this can help with GPU access. This is running a fresh release of OBS from Github but we have experienced the same issue with the current release as well, hence trying a more up to date build to see if it made any difference.
Just wondering if anyone has encountered the same, or can offer any suggestions?