Audio output lost after a while (hours to a day)

General
1

Hi,
I’m trying to output mp4 clips via Blackmagic i/o card
everything works perfectly for a while, after a few hours (possibly a day) - the audio stops playing,
video still playing, but all outputs of the blackmagic have no audio.
I restart the casparcg server, reload the clips and the audio works again for a while till it happens again,

what would be the right way to start debugging that?
it’s different clips everytime, all 3 outputs I use stop providing audio at once

Thanks!

2

Are you running in 50 or 59.94?
What version of CasparCG?

How does the DIAG window compare between the audio working and not working?
Anything in the logs?

3

Hi Julusian, thanks for the quick reply!

I couldn’t find any errors in the log prior to the audio stopping,

When I noticed the issue I shut down the casparcg server,
in the log it says:
[2023-07-31 13:27:25.647] [error] DeckLink Duo 2 [3-3|1080i5000] Failed to schedule audio.
[2023-07-31 13:27:25.647] [info] DeckLink Duo 2 [3-3|1080i5000] Scheduled playback has stopped.

but I don’t know if it’s normal, might be a normal shutdown behavior (?)

there’s another warning a few hours earlier but I’m almost sure the audio worked after that:

[2023-07-31 06:52:43.122] [warning] DeckLink Duo 2 [4|1080i5000] in-sync changed: -0.556896
[2023-07-31 06:52:43.170] [warning] DeckLink Duo 2 [4|1080i5000] out-sync changed: 0.02
[2023-07-31 06:52:43.205] [warning] DeckLink Duo 2 [4|1080i5000] out-sync changed: 0.04
[2023-07-31 06:52:43.644] [warning] DeckLink Duo 2 [4|1080i5000] out-sync changed: -0.158021

do you think that those messages contain any valuable information?

4

I am not sure if that is normal or not, I suppose it could be depending on timings.

If it was only a couple of log lines then I don’t think there is anything to worry about there.

What decklink driver version are you using?

5

I’m using Blackmagic 12.5.1 with a Decklink Duo2 card at 1080i50

I’m running CasparCG server 2.3.2

is there a recommended version for casparcg/decklink drivers?

6

I have had similar audio issues in the past caused by unstable Genlock. (Blackburst/TriLevel). Do you use Genlock ? If yes, try without or try changing from TriLevel to Blackburst if possible.

7

Hi Dirkdamerau,
We have 2 machines, one with genlock, the other without
it happens on both, I’m not sure it’s genlock related…
I can tell you that the switcher that the SDIs are connecting to is shutting down every day,
Not sure if this could cause such a behavior

8

I don’t think a mixer shutdown has to do with this as SDI is unidirectional. But to be sure just leave the mixer running for a few days.

9

yeah, I guess you’re right,
I have no explanation for that,

after a few days of work I can say that we still lose audio after 15-20 hours since startup,
restarting caspar server solves the issue for an hour or two,
Rebooting the whole machine fixes it for the next 15-20 hours

Any ideas would be much appreciated