Sometimes I encounter a bug that makes video playback on my Mac useless. When the error occurs, most of the time after I wake up and unlock the Mac after an absence, videos play at hyper-speed without sound …
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This issue has affected both offline video playback for local video files and online playback for videos hosted on sites such as YouTube. Although annoying, it is a simple solution that can quickly remedy the problem.
To see the problem in action, watch the short video below, where I present the quick video playback error and demonstrate it.
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To fix the fast video playback error
Before you do anything, be sure to save everything you have opened.
To resolve this issue, open Activity Monitor and under the CPU tab you will find the coreaudiod process. Click the 'X' button in the upper left corner and select Force Quit . This will kill Korean audio, but it should restart immediately.
When the coreaudio restarts, it will appear under the CPU tab. Afterwards, close Activity Monitor and try playing a video. If resolved, video playback should return to normal with audio and at standard 1x playback speed.
A reboot will solve the problem too, but rebooting takes a lot more time than just restarting the core audio daemon via Activity Monitor.  In my case, I use an external audio interface, but others have expressed to me that the error occurs without using an external interface. A few of the users I've talked to who have experienced this error regularly use Apple's professional media apps like Logic Pro X and Final Cut Pro X.
Have you experienced the fast video playback error on macOS? Have you found a better solution? Sound off in the comments below with your observations.