I have a MBP 2015 (10.13) and I've tried to use QuickTime player to do a screen recording using PhotoShop 3 times now but each time the file is corrupted and fails to save with the error "Can't open".
When providing model information in cases like this, it might help to know if the MBP was an early 13-inch, 2.7GHz I5, 2.7GHz I5, 2.9GHz I5, 2.9GHz I7 or mid 2015 15-inch 2.2GHz I7, 2.5GHz I7, 2.8GHz I7 system.
After about 5-6 minutes the fan starts running really high and at that point the video stalls (audio is fine) and can't be saved. I have 20 GB of HD space available. Photoshop is PAINFULLY slow during recording and barely usable but can this MacBook "Pro" seriously not record more than 5 minutes of video without burning up? The final video is only 700MB.
Any ideas? Is PhotoShop the culprit?
Suspect you may have already answered your own question. I believe PS is and has always been known as a power hungry app. And, while QTX is programmed for a much wider range of operational power requirements, encoding of video can be CPU intensive and, therefore, does have a lower limit below which it cannot drop. Basically, you can easily confirm your hypothesis by opening the Activity Monitor app in your "Utilities" folder. You can then determine the optimum CPU requirements for each app running independently on your system and then compare those figures with the power requirement distribution between the two apps running simultaneously. I suspect you will see your system quickly going into the turbo boost mode (overheating the CPU and causing the fan RPMs to increase) with PS attempting to "hog" more and more CPU power until QTX simply cannot keep up and virtually stalls out.
