Video Delay During Live Stream [Possible Hardware Issue]

GertjanB

Hi,

Today I encountered a problem I never had before, I don't know if it is problem with Isadora or something else so I'm curious if somebody else encountered the same problem.

It's a live stream, mix of 2 webcams (Logitech C920) with video's (all in HAP, also tried proress, but no difference)
For audio we are using Loopback to send the audio of Isadora together with 3 other microphones to the audience.
(1 minicontroller to trigger the cue's and 1 projector as a visual feedback for the actors)
We use the Virtual webcam to send the video to the audience. (on our own site - the audience can not now its a live stream)

During the rehearsals we didn't have problems and now today with the first show both webcams had a very big delay. The delay was in the input (even before the green key for example) so it's not an internet or website issue.
The only thing we had during rehearsal is the fan's blowing like creasy sometimes (that also happend during editing in After effects and premiere)

I had this problem once during rehearsal on an older computer but never on my Current computer (specs underneath)

To find the problem I started testing:
Directly after the show I deactivated all scenes an saw that the load monitor was fluctuating between 2 and 45% (in a consistent rhytm up and down) When looking to the activity monitor I saw that a proces called VTDecoderXPCService was taking up 45% of my CPU (constantly) I close down everything and it only went away when I closed Isadora (as the last step)
I didn't see big problems with the GPU.

I'm now doing more tests and I haven't encountered it again. So it's a big guess what the problem was.

I'm trying:
everything is now in fullHD I'm setting everything to 720P to see if that makes a difference.

Anyone else tips?

Specs:

MacBook Pro (16inch, 2019)
2,3 Ghz 8-Core intel Core i 9
32 GB 2667 MHz DDR4
Intel UHD Graphics 630 1536 MB

GertjanB

I may have found the problem.

After 4 hours of testing I found that it was a combination of problems.

It only occurred when everything was on, Loopback, virtual webcam and our website.
It all went well until 1 video. This video had export problems and I couldn't export to Hap (premiere problem for an inexplicable reason) So I exported this one to Proress for lack of an other option.

When testing only in Isadora I didn't see any problems. But when everything was on, virtual webcam started using more than 450%CPU

I now exported this video back to HAP and I don't seem to have the problem. I still have to test more thoroughly but could this be the problem?
That due to the discontinuation of QuickTime, the virtual webcam and proress don't want to talk to each other?

There is still a small delay after a while and also the pulsing of the load is still happening. (even when no scene is active, the load is going up and down between 2 and 45%)

dbini

Hi Gertjan, last weekend i had issues with the Virtual Webcam after a few hours of using it. one time it locked up and took 10 minutes to force quit. the other time, my Sound Watchers seemed to have slowed right down, getting about 1 frame every few seconds (i've used this same patch without the Virtual Webcam out for a whole day before with no issues.
I'm starting to think the Virtual Webcam is a bit unreliable.

GertjanB

I didn't experience any difficulty's with the virtual webcam. But I found the problem.

It was a strange problem with the projector we use as visual feedback for the actors. When I close the stages the problem disappears. So I disconnect the projector. And we wil now use a screen that doesn't give problems.

I also encountered the same problem yesterday when using an Elgato HD60S + To externally record my output.

mark

@dbini said:

I'm starting to think the Virtual Webcam is a bit unreliable.

If you have issues to report, please open a ticket and report them to us and we will do our best to fix them. It is really important to us that Syphon Virtual Webcam works and works well.

Best Wishes,
Mark

mark

@gertjanb said:

It was a strange problem with the projector we use as visual feedback for the actors. When I close the stages the problem disappears. So I disconnect the projector. And we will now use a screen that doesn't give problems.

Do you mean a physical video projector or a Projector actor in Isadora? Is there something for us to work on/solve here? If so please let us know.

Best Wishes,
Mark

GertjanB

@mark

It was a physical projector and also a external capture card (Elgato HD60S +).

The stress for the premiere is over now, the show is running with a workaround. I'll test this problem more thoroughly and make a support ticket with steps to reproduce.

mark

@gertjanb said:

The stress for the premiere is over now, the show is running with a workaround. I'll test this problem more thoroughly and make a support ticket with steps to reproduce.

Thank you for taking the time. I'm glad the show is open and running well.

Best Wishes,
Mark

DillTheKraut

@gertjanb

This sounds like an issue I experienced with some projectors. Digital display devices, like projectors and flat screens tend to have a delay, if they do picture optimisations or manipulations. The amount depends on the device itself and often on specific settings, regarding color, scaling, up to internal warping. MOst times this isn't to much of an issue, as it is just some frames. But if you depend on it for e.g. timing on music, it can become an issues.
I even had this issue once with different delays on the same type of projector, and at least thought to have the same setting, finaly replacing the one with the issue.