I'm essentially stuck on Mojave for this exact reason. Since QT7 Pro was so ingrained in my workflow, I was certain that within a year or so of Catalina (or whatever the first 64bit only OS was) an alternative would show up in short order. Guess I underestimated how many users rely on it
- like the OP I couldn't believe I had to explain to folks why I missed it! ...everyone who says, "just use iMovie (FC, Premiere etc)" is clearly unaware of why QT7 Pro was/is so useful.
The How-To video above, by Michael Kinney, is quite helpful actually. I learned a lot from it, but the QT7 Pro function I use most often is
Delete, Extract/Add Sound to Movie (I'm a sound designer and composer). QT7 Pro does a ton of other useful stuff, but if QT Player could do this operation (it can
not, correct?) I'd probably stop complaining and move on with my life.