Bill Ravens
Forum Replies Created
-
I found one thing I have been doing wrongly in Resolve. Despite the settings in the configuration page which select full range data, I still need to deselect “Auto” and select “full range” for each and every clip in the media pool. I was assuming that setting up the configuration page properly addressed this issue. Apparently not.Thanks, Joseph, for the clue.
-
Mike,
Of course, you’re quite right. Jumping to insinuation and borderline insulting is really not very effective. So, let me elaborate. This issue has been reported on the BMD COW site, as well as in an email to BMD Customer Support. Their response has been nil.It is exceedingly frustrating to have to work to customers expectations while dealing with color issues. I’m sure you understand what I mean. My apologies for seeming to offend anyone. I would just like some sort of response from BMD that says they recognize a problem…or not…..something that says they heard the complaint from myself and others. I’m not alone.
Given that this is beta firmware, I have to take what I get. Nevertheless, it would be nice, as I said, to think they are on top of this issue….or if they feel the problem is entirely my fault, that they at least offer that, as a response.
My biggest concern is that there is data being lost in the shadows and highlights. Having some feedback from BMD that this is not happening would certainly help out. But their silence is the issue.
-
you guys didn’t read what I posted. Yes, it’s an Avid issue because it’s Avid’s DNxHD codec. BUT, the problem is an apathetic BMD who doesn’t know how to use the codec, and hasn’t read the AVID SDK. There’s a switch inside of the codec to choose the video range. And BMD, in all their wisdom, thinks we, the user, doesn’t need the option.
There’s all a very good writeup on the use of the codec at the Calibrated {Q} website, here….
https://www.calibratedsoftware.com/downloads/CalibratedQ-MXF-UserGuide.pdf -
The problem has been reported to BMD. As of this writing, they prefer to ignore it. Use of the DNxHD codec provides for many internal switches, as described in Avid’s SDK. One of the internal switches in the software is to “remap” all input values assuming the input is full range RGB and output studio range 16-235. The problem arises when 16-235 is input and it is incorrectly remapped to 32-215. It’s a function of the encoding/decoding happening in the hyperdeck.
My own research into the recorded signal shows no data loss due to clipping superwhites and superblacks, however, this is an unfortunate situation. Hopefully BMD will offer a firmware update allowing the user to choose what color range they want to output.
-
James….
I recorded HD color bars from my FS100 to the Hyperdeck. Opening these files in Resolve shows the levels to be remapped to levels that are compressed across the entire range. We know all this. Using Resolve to expand the levels back out, there appears to be no lost data or clopped superwhites/superblacks.
My plan, as a workaround, is to simply reexpand the acquisition in resolve to RGB levels.
-
Good call! I agree with you guys. The option should be given to the user, full range RGB or remapped YUV range. I’m not convinced that there isn’t clipping going on. BTW, the pedestal level is really a function of the exposure. I used an example that was exposed to 0 RGB. If I had exposed to 16 RGB, the Hyperdeck pedestal values would have been around RGB32. Calibrated{Q} explains the issue very well in their user manual.
BTW, I’m using the latest DNxHD codec, v2.3.7, and I’m still seeing the gamma shift.
-
[Kristian Lam] “Thanks Bill,
We’ll look into this.
regards
Kristian Lam
Blackmagic Design”Kristian…
FWIW, there is quite a detailed explanation of how the DNxHD codecs work in the following user guide from Calibrated{Q}….
https://www.calibratedsoftware.com/downloads/CalibratedQ-MXF-UserGuide.pdf -
Thanx, Kristian…here’s some frame grabs from Avid
-
adobe premiere? no!
I’m importing files into Avid media Composer 6.01 or Davinci Resolve. They both show the same gamma shift. -
I’m running MC6.01 with the latest DNxHD codecs on a PC. Importing DNxHD files recorded on a Hyperdeck Shuttle 2 are shifting the gammas incorrectly. This happens whether you use the DNxHD direct or QT wrapped DNxHD recording method.
Bringing in the QT wrapped DNxHD by linking via AMA does not help. And the ability to change the range within Media Composer is greyed out for Quicktime DNxHD linkage.
BMD has yet to respond to this problem. They seem to be ignoring it.
