I am writing this post as the clock on my computer rolls past 2:00am. I met up with an old friend in Rahat this afternoon and I had coffee at 5:00pm without thinking of the sleep-related consequences. So be it. As I begin, there are two things I hope will come to pass once I finish. First, I hope that the spinning pinwheel currently being shown to me by my Adobe Premiere project will magically resolve itself and I can get back to work without force-quitting the program and opening my last auto-save. Second, I hope my friends who have heard my "Macs never crash and that's why they're awesome" speech will refrain from throwing this in my face.
While I am patiently allowing my computer to work out it's computational bullshit, I wanted to share two lessons learned amidst the fervent editing of the TEDxBGU videos. One is obvious and the other is ridiculously important (again, if you happen to be me).
I'll start with the lesson that has wider appeal. When I started editing the TEDxBGU videos I was frustrated by the fact that when I brought the footage from a particular speaker into Adobe Premiere, synced all the video clips with the master audio recording and began to set the multi-cam timings, my computer could not even hope to keep up with the stream of data needed to display three video feeds in real-time. Although my memories of editing last year's videos in the dark, sticky heat of a youth hostel in Akko are a bit foggy, I seem to remember using a 7200rpm drive (with a Firewire 800 connection) and completing the multi-cam edits with relative ease. Most of that work was done at 2:00am as well, though, so it's hard to be sure.
In any case, it was just not working for me this time around. I tweaked my Video Previews and Media Cache settings. I toggled my memory settings between Memory and Performance modes (and I still can't tell a difference between them) and even tried every possible configuration of arranging the source files of different on--board and offboard drives. No dice. Essentially what I found myself doing was setting the multi-cam timings by guessing (while the displays refreshed every ten seconds) and then rendering all the previews before running through the whole talk again and making a slew of adjustments based on a truly real-time display of what I had cut. Inefficient, tacky and amateurish. Not cool.
Ultimately, after finishing six videos the old-fashioned (read: stupid and inefficient) way, I finally tried the proxy file approach. I transcoded the source files for one of the talks down from 24Mb/s AVCHD to 640x480 Quicktime files and did a batch replace of all those files in Premiere. When I opened up the sequence and started my multi-cam edits, the computer heaved a visible sigh of relief as it began to stream a grand total of 3Mb/s off my solid state drive. This compared to the 73Mb/s I was demanding of it earlier. Once I finish, all I have to do is replace the low-res files with the HD source files and render away. Quick, easy and effective and I have no idea why it took me so long to just give it a try. So that's lesson number one: "Proxy files, proxy files, proxy files. Just do it."
Lesson number two is far more technical and honestly I don't even care about all the little details so I'll just share the highlights in case someone stumbles onto this page from Google with the same question I had one week ago. Avid recently came out with a new video format called DNxHD which is essentially their answer to the ProRes family of codecs. The DNxHD is supposed to be incredibly space efficient and allow you to transcode proxy files and/or source files while maintaining high image fidelity across a variety of bitrates. In an attempt to solve the aforementioned multi-cam jam I tried both ProRes 422 and DNxHD formats as proxy files before going with a lower resolution. With one talk, I edited the the footage using DNxHD36 (Mb/s) files and proceeded to render the final version when I was done. What I found after five hours of rendering was that all the highlights in the footage were filled with flourescent, pixelated color distortions (see image). I switched output formats and tried adjusting and removing the effects I had on the video tracks, but to no avail. Finally, after a last-ditch effort to find answers on Google from the search query "Adobe Premiere render highlights distorted" I came across a cryptic reference on a message board to the fact that Abode Premiere and DNxHD don't get along so well and using DNxHD sourse files will result in distorted highlights. I don't remember where I found this nugget or who it was that shared it but that was the key to my problem. I replaced the DNxHD files with the original MTS files and all was well again in the universe.
So lesson number two is: DNxHD is kinda quirky. If you have render distortions, try a different source file. See? That one's much less exciting. And yes, in the time it took to write this post Adobe Premiere worked out it's computative skullduggery. Back to work.
Since I like to end my posts with a video, please enjoy this talk given by Hagit Damri at TEDxBGU. Not the funniest or most entertaining talk of the day, but far and away my favorite. [youtube http://www.youtube.com/watch?v=1EW4C4ZW82s]