I work with a lot of iphone footage. Last year, I was cutting with CC 2018 on a mid-2014 MBP with 16GB RAM and Mojave OS. I would use Handbrake to convert the HEVC variable frame rate iphone footage to constant frame rate H.264 MP4 files. I know that is not a great codec to edit with, but it actually worked fine for these relatively short, simple videos.
This year I upgraded to CC 2020, and to a 2018 MBP with 32GB RAM and Catalina OS. Suddenly the same sequences with H.264 clips that were running fine on CC2018 have gotten way slower to navigate around. Again, I know H.264 is not the ideal codec to edit with, but any idea why performance would have gotten so much worse on a supposedly faster system?
And that leads me to my next question... what is the best workflow when having to cut iphone footage in Premiere? I had been using Handbrake to convert to constant frame rate, but I think that will only convert to H.264? I just discovered a shareware program called "Shutter Encoder," which seems pretty powerful, and will allow me to convert to ProRes, though the files will be huge. Wondering what everyone else does?
FYI, here are the old and new system specs for the weirdness I mentioned above.
My understanding is that H.265 is even more problematic to edit with than H.264.
The key to getting audio in sync is to convert the iphone files from a variable frame rate (VFR) to a constant frame rate (CFR). Both Handbrake and Shutter Encoder will do that. Shutter Encoder was a program I just learned about today on a Reddit thread, and I will say that so far I'm impressed with it's versatility. www.shutterencoder.com