Audio sync issue in recording
I'm currently recording and streaming at the same time. The stream is great, but the recording has an audio sync issue - the audio is about 7-10 frames behind. I'm unsure as to why the recording has the issue but the stream doesn't. Is there a setting I'm missing?
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I'm not sure how you're determining the sync difference given that Wirecast processing is the same for both. The encoder settings choices for recording and streaming generally don't have any impact on sync. Please make sure you're using the current version of Wirecast (14.1.x).
I'd suggest doing a test recording using Apple ProRes MOV and use that as a guide for adjusting sync. -
Mike Pomeroy, same here. We didn't change are encoder setup for a while now and sometimes our recording is also out of sync. Stream is never a problem. Both are mp4 x264, with the recording part on a higher bitrate. CraigS I understand that changing to Apple ProRes MOV would be better. However, our workflow makes it more difficult to work with larger files. Backup is more costly, rendering / uploading recordings takes more time. It will be possible to do so when i can automate this process.
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Hugo Snippe said:
We didn't change are encoder setup for a while now and sometimes our recording is also out of sync. Stream is never a problem.Have you updated to 14.2?
Hugo Snippe said:
recording is also out of sync.Have you checked monitoring the audio locally?
Some sources can be out of sync which is why we have a source-specific audio/video delay feature.
Hugo Snippe said:
understand that changing to Apple ProRes MOV would be better.That would determine whether the GOP-based x264 encoder is the issue. If the issue is still there with ProRes then it may be in the source/processing which may necessitate using the audio/video delay of a given source.
The encoders for streaming and recording are the same but the settings can be customized.
To start with you should only use our presets especially for recording.
Also how one plays back the recording is also a factor. Recorded x264 files often will drift out of sync in an NLE but will be fine in most file players.-
CraigS we updated to 14.2 before our last broadcast. Switched recording to mov recording preset. We changed our workflow to encode the final recording to a upload dir that syncs to vimeo. And by using anydesk as remote desktop we can shutdown our macbook from remote. Will report if we encounter any sync issues.
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Hugo Snippe Thanks for doing and that.
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CraigS just noted your comment on Hugo Snippe reply, it is within the NLE that I've noticed this most when editing for social. As such, are you saying recording in mov format will eliminate this issue?
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Mike Pomeroy Wirecast records a variable frame rate which will generally play fine in a player but may drift over time. While it can happen with MOV as well the frame rate might be less likely to vary assuming proper throughput to the recording drive and drive speed.
If there's drift in an NLE one can either re-encode and reimport which should lock the frame rate or one can "time stretch" as needed in the NLE.
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