Quicktime slow to start playing a file

Question

Level 1

10 points

Quicktime slow to start playing a file

Since upgrading to High Sierra, on my 2014 MacBook Pro Quicktime takes unto 20 seconds to start playing an MP4 file when it is either double clicked, or opened via File > Open. There is no spinning colour wheel, or anything, just a blank quicktime screen until the 20 seconds are up and the file starts to play. This happens on any MP4 file selected. Playing the SAME file on my iMac, Quicktime starts playing immediately. VLC does not have any delay on the MacBook either.

In an attempt to cure this I have done a clean installation of High Sierra, but exactly the same fault exists.

Does anyone have any tips or advice please?

Posted on Sep 29, 2017 10:00 AM

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Answer 1

Jon Walker

Level 6

19,489 points

Sep 30, 2017 8:38 AM in response to Jon Walker

ADDED NOTE:

Just noted use of a "Mono" AC3 audio track in my HEVC M4V files triggers the file "verification" processing routine noted above to block opening of the file in QT X under High Sierra. Assume this may also be true for MOV and MP4 files with similar audio tracks. Strangely enough, a DTS passthrough version of the same audio was not blocked.

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Answer 2

Jon Walker

Level 6

19,489 points

Sep 29, 2017 11:54 AM in response to sollevs

Does anyone have any tips or advice please?

Not sure anything can be done at this point. I suspect this issue is due to the recent High Sierra "Security" update. QT X now appears to "verify" at least some (if not all) files as they load. Some files open a progress bar as they are loading. Here is a quick screen capture clip of the progress bar I recorded earlier when first attempting to respond to this post:

VerifyClip.mp4

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