Faltering Audio in Program-out but not in Preview
Hi all,
We've had a broadcast with three guests coming in via NDI (MS Teams). Program was streamed in H.264 25fps to an rtpms server and parallel recored as MOV. We've used the latest version of Wirecast Pro (14.2.1) on a Mac. All went very well aside from audio: From time to time it was faltering and choppy for a couple of minutes and then it was all good for another couple of minutes.
BUT: Audio was only faltering/choppy on program-out (also in recording and stream) but when I listend to the preview audio it was clear and all good. That would mean that something happend from preview to live!? CPU was around 20% all the time so this shouldn't be the reason.
Any ideas what caused that faltering/choppy audio on program-out and how I can avoid that in the future? Thanks a lot - highly appreciate any ideas.
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Michael Zerrath said:
three guests coming in via NDI (MS Teams)Was that the only audio source?
Michael Zerrath said:
BUT: Audio was only faltering/choppy on program-out (also in recording and stream) but when I listend to the preview audio it was clear and all good.What encoder settings were used for streaming and recording (be very specific we need complete settings)?
Streaming can be impacted by ISP and Server-side issues.
Local recording is usually the "confidence" (verifying output is good) but can be impacted by drive throughput for example (so including drive specs and free space are also important).Michael Zerrath said:
I listend to the preview audio it was clear and all good.Did you try listening to monitor output?
It's entirely possible Preview and Monitor may be different.
Michael Zerrath said:
H.264 25fpsWas Wirecast Preferences Video Display Rate set to 25fps?
Was the local MOV recording set to 25fps?
Can you link to the local recording or portion from just before the issue to just after it clears up so we can see/hear what's happening at that point? -
Hi CraigS , thanks for coming back so quickly.
NDI via Teams was the only audio source (NDI feeds assigned to placeholders and muted except to one participant).
I've attached screenshots both from the encoder settings for streaming and for recording. Re the specs of the computer: It's the latest MBP 16 with highest available configuration. Free disk space is 650 GB.
I've also attached a short snippet of the audio, due to privacy reasons (client work) without video.
Do you need anything else? Does the above mentioned make sense to you?
Thanks so much for your support,
Michael
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Michael Zerrath Using Apple h.264 can have issues given it's highly variable bandwidth. Unless you need use it to lower your CPU% under 60% I'd suggest you use x264.
Also you're using two different frame rates. That's not recommended. If your sources are 25fps you should use 25fps throughout. Also your Wirecast Preferences Video Display Rate are a factor and that should be set to 25fps.
Given you say incoming NDI sounds good I'd first address the signal processing by setting everything from Wirecast Preferences and all encoders to 25fps. That's assuming your NDI sources are 25fps. Otherwise you may need to change everything to 30fps.
I'd also recommend running a test by ISO recording each of your NDI inputs as Shot ISO and the source frame rate and check those as well.
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Thanks a lot, CraigS . I'll give your tipps a try.
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Michael Zerrath 👍
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