@Andrea: I’m going to test your workflow tomorrow. Thank you for all your effort! Unfortunately, I have a more urgent issue now. That’s why I need to post here first (:
So, I couldn’t find any specific information about the implementation of DPX except one thread which ends with unanswered questions. In conjunction with my other thread about outputting multiple crops of one input sequence I now need to output them as DPX.
As this issue is relatively urgent, I post here first and start à la trial and error at the same time. If I just need to type DPX as the codec I apologize for my hasty opening of this thread in advance
Input is linear EXR.
we need 10bit log dpx output but to know how to output 16bit linear would be useful for the future, too.
I just found a jpeg workflow documentation and transfered that to DPX and I am testing LUTs at the moment.
I think, I get the image I want when I change the output in the submission dialog to .dpx, apply a sRGB lut and use the writeToFile function. My input images changed to DPX (I think they are somehow sRGB) and when applying sRGB in Draft it looks correct in RV.
Paul and I had a long talk about the Draft and RV LUTs a few months ago so I could reuse all the info
I am not sure about the bit depth though as I didn’t specify anything in Draft.
big edit:
The only question that remains is the bit depth. I made my script render the input to ./Draft/LEFT, /RIGHT, /CENTER as .dpx without the need of changing anything on submission. If anyone needs the template just drop a line (:
The output for DPX currently defaults to 10 bit, and at the moment we don’t have the setting to change that exposed. Are you sure it’s the sRGB LUT you want? I’m still learning about which LUTs do what, but I think you might want the Cineon LUT. But yes, all you need to do is read the file, apply the correct LUT, and then write to a filename with the .dpx extension.
My apologies for not noticing this thread yesterday… I need to change my settings so that it notifies me when there’s new threads added to this board.
Yeah, LUTs and colorspaces cause me some headaches. As the input somehow changed colorspace again, I had to remove the LUT lines completely…
I guess, it’s all dependent on how the dpx files were written and sometimes they’re not written as Cineon and therefore I have to apply other LUTs and check until I have the right look.
Seemed to work almost without issue, there’s one thing left though. Do you have any idea why my script stops one frame too early?
I choose 0-99 on submission and the script prints startFrame 0 and endFrame 99. So, everything is correct here but the output is 0-98.
Bobo is correct, Python’s range goes up to but not including the end value specified, and so adding 1 (in cases like this) is necessary. If you’re curious as to why, let me know, and I can type up the explanation.
I had a look at your code, and your application of the LUT is well before you read in the images. If you want to apply a LUT to an image, you first have to read the image, then apply the LUT. Since the images have overlapping regions, I recommend applying the LUT before the deep copying and cropping, so that you only need to do the transformation once per input frame:
lut = Draft.LUT.CreateCineon() # or whichever LUT you want to apply
...
for aFrame in range(theLoopStart, theLoopEnd+1) :
...
firstFrame = Draft.Image.ReadFromFile(inFilePattern)
lut.Apply(firstFrame)
firstFrameL = deepcopy(firstFrame)
...
(Where “…” represents code I left out, of course.)
Wow, haha. Funny, that no one ever noticed the previews are missing the last frame. I guess working with handles was a good decision
Thanks for all the support.
