A/V Controls button for Slow motion in QuickTime Player (10.5)?

Question

I find that Apple answers this question

Slow motion in QuickTime Player (10.5) in Mac?
From https://discussions.apple.com/thread/250493652

You can use the keyboard shortcuts below for slow motion playback:
∙ Continuous press K+L for forward slow motion with audio
∙ Continuous press K+J for reverse slow motion with audio

My question: is there also an A/V Controls button like here explained in https://filme.imyfone.com/video-editing-tips/how-to-speed-up-videos-on-quicktime-player/?

I did not find such A/V Controls button available.

If not, which versions of QuickTime Player have that QuickTime Player?

Answer 1

Apple discarded a lot of the old "Pro" control & editing aspects when it updated Quicktime 7 to Quicktime 10 [there was no 8 or 9].

Your linked page at imyphone is actually using an old Windows version, equivalent to v7, long abandoned.

You can still get Quicktime 7 but I don't know if it will work on any recent macOS. It will also be difficult to get hold of a Pro registration number if you need to activate the higher functionality - you can't buy them any more.