Audio and Video Sync

  • Updated

Video and audio signal issues are a common hurdle for most live-broadcasting environments. While Resi’s technology is built with the integrity and reliability you would expect, many of the signal issues our customers run into have less to do with faulty equipment and more to do with improper setup. This is why we recommend that you read our article on the basics of signal paths and run the proper tests before the start of your event.

Synchronization issues between your audio and video signals most often occur before they reach your encoder. You can determine whether your signals are syncing properly by plugging your camera into the back of your encoder, running an event, and checking the video signal.


Out of Sync in Live Video

In some live or downloaded videos, you may notice the audio is not in sync with the video. This typically occurs when running audio either through a digital audio workshop (DAW) or if your encoder has been started without a video signal.


Audio is lagging behind the video

This usually occurs when running content through a digital audio workshop (DAW), for example ProTools or Logic Pro. In some cases, there’s a buffer causing latency in the video. Resi doesn’t recommend using a DAW when encoding and broadcasting content. 

In a typical signal path, audio runs from the content source to an embedder/switcher, then to the encoder (Learn more). In this case, audio should be instantaneous. To fix the issue, check your signal path and if you’re using a DAW, ensure it’s not adding latency in the video. 

Resi is unable to troubleshoot specific signal paths and DAW setups. For general troubleshooting help, see Troubleshoot Audio Issues.


Video is lagging behind the audio

In this case, sounds take place before the actions in a video. This typically occurs when the encoder loses a video signal or when it is started before turning on a switcher. 

Encoders construct timelines and establish audio/video sync at the point of starting. If you lose the video signal and later notice the audio and video are out of sync, stop and restart the encoder. It should catch up and the audio should be instantaneous. If you’re unable to get your audio and video in sync, contact our technical support team for assistance. 


Out of Sync in a Downloaded Video

You may download a video and notice the audio and video are out of sync, which can occur when using programs like Quickplay to replay the content. Resi recommends re-transcoding your video with a video transcoding tool such as Handbrake. Learn more

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