Without jumping through hoops to ensure quality control, encoding the processed video from Premiere to import into After Effects for another round of processing is NOT visually lossless. You are mistaken. Furthermore, what you are suggesting would have easily taken me 10x longer than what I ended up doing. You're suggesting that for every single time I punched in on a shot (probably once every 2 seconds or so over the course of a 4.5 minute music video = 100 different shots), I send the individual shot over to AE (along with the entire bassline soundtrack for each shot to maintain sync) to apply my beat reactor. Not only that, but then I export nearly the entire video (minus those 100 shots) to a lossless format, import that into AE, apply the same beat reactor, then export it from After Effects to reimport it in Premiere so that I can recombine it with the 100 other shots I sent to AE individually. Do you have any idea how long that would take? What I did was select basically the entire music video (except for a couple of video tracks) sent it to AE, applied a beat reactor (by parenting all layers to an animated null, I ensured that even previously transformed shots maintained their best possible quality), came back to Premiere and exported the whole thing. The render took all of 3 hours on my machine. I didn't experience any stability issues. Aside from building the beat reactor effect, my process involved about 6 clicks of my mouse, compared to the 600 that your method would involve.
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