The ProRes Issue

The ProRes Issue

The ProRes Issue

It’s no surprise to anyone working in post these last few years that ProRes has become a standard working codec in the process. That being said I still demand 10 bit uncompressed files or image sequences as masters. The issues with ProRes and its famous “gamma shift” magic is just way too much of a liability to overlook. The issue is that ProRes is just not stable in terms of knowing for sure that the file you send or receive is in fact the file you intend to send or receive. After much review of this color shift it seems that not only is it annoying but no method to this madness exists. Even after several years of working with it I still find issues even today with new applications. If you are not familiar with this issue let me give an example of how this can become a real problem. Let’s say I have a an editor who has a section of an edit and wants to start some color grading test (yes we do test stuff). They want to start setting a look for a part of the edit as they are about to enter the picture lock phase and we are getting ready for grading. So the editor encodes a section of the timeline as ProRes and sends the file over. Now the colorist picks up that file and brings it into DaVinci, sends to scene cut detection and starts applying a look. Saves some LUT’s/ setting for when it gets time to online and grade this for real. Everyone is happy so far. Then the editor send that treated file out to the vfx folks who are about to apply some effects. The vfx guys use the color graded version to get a sense of where the shot is going. So said VFX folks do their thing. Everyone loves how this project is coming along.

Well the editor goes back to editing for a few weeks and the rest of the team hear nothing as they approach picture lock (directors can never stop cutting). Finally they lock and bring the xmls, Edl’s whatever back to the grade. We start applying the color setting we went over in the past. But wait nothing is looking like our test? The VFX guys are calling and they are saying that the comps they made are not looking correct with the final locked files. What the heck is going on? We already did all this testing earlier to make sure we would not be rushed on deadlines in the finish. But nothing is looking as it did during our test? What happened?

You see the editor was working on clips transcoded from whatever to ProRes when they started editing and they want to do a ProRes workflow thru color grading (not my thing but eh ok). The ProRes files that where transcoded for edit looked one way but when the editor made that export of a section of the edit, the gamma actually shifted. Since the VFX and colorist just thought this was shot poorly and had not seen the actual raw footage they just went ahead setting looks on what they were given. However the editor exported the files in an incorrect manner (and it’s more Quicktimes fault then the editor). So now all that work the colorist and VFX did is all wasted time and they essentially have to start that process all over. Wasting time, wasting money, and making everyone nervous about hitting the output deadline.

I test every workflow from top to bottom twice before putting it into play. However I have seen the issue in testing phases. I have seen this kind of stuff happening around me on an almost regular basis. Way to regular to even consider ProRes as a mastering codec. In fact when I hear ProRes my brow usually raises. My rant is simply to restate my belief that you must test workflows A LOT. Find out what platforms, software and pipeline the team is going to use from start to finish and test moving the files down the pipe. Do it twice. And when a situation occurs outside the scope of the initial testing, test again. ProRes is inconsistent. Some applications shift it, Some do not. Some even shift the color on simple transcoding. Thing is that it may look ok on one platform but not on another. It’s all over the place. Lately I have been using DNxHD as my middle ground file over ProRes and I find a lot less issues. Even better DPX, but for smaller projects sometimes that can cause a world of hurt for the offline editor. For TV mastering I’m still into 10 bit uncompressed or DNx these days.

I test every workflow from top to bottom twice before putting it into play. However I have seen the issue in testing phases. I have seen this kind of stuff happening around me on an almost regular basis. Way to regular to even consider ProRes as a mastering codec. In fact when I hear ProRes my brow usually raises. My rant is simply to restate my belief that you must test workflows A LOT. Find out what platforms, software and pipeline the team is going to use from start to finish and test moving the files down the pipe. Do it twice. And when a situation occurs outside the scope of the initial testing, test again. ProRes is inconsistent. Some applications shift it, Some do not. Some even shift the color on simple transcoding. Thing is that it may look ok on one platform but not on another. It’s all over the place. Lately I have been using DNxHD as my middle ground file over ProRes and I find a lot less issues. Even better DPX, but for smaller projects sometimes that can cause a world of hurt for the offline editor. For TV mastering I’m still into 10 bit uncompressed or DNx these days.