Blackmagic Forum

I'm making an clip for and need a small scene of this video file:

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Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5.1@High
Codec ID                                 : V_MPEGH/ISO/HEVC
Duration                                 : 1 h 12 min
Bit rate                                 : 255.5 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 23.976 (24000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0 (Type 2)
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.260
Default                                  : Yes
Forced                                   : No
Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : Display P3
Mastering display luminance              : min: 0.0050 cd/m2, max: 4000 cd/m2
Maximum Content Light Level              : 1001 cd/m2
Maximum Frame-Average Light Level        : 351 cd/m2

I need it to be SDR rec.709.
What is the correct input color space I should use?

It looks like P3 D65 1000nits master.
I think you need to set Input Color space to P3-D65 and gamma to ST2048-1000nits.
You probably want to use ColorSpaceTransform plugin.

You could use either the Color Space transform OFX or set the correct input and output using RCM or ACES. Input as Andrew described above and output Rec709.

You would need to either tone-map the transform or manually map to the more limited Rec709 range using the LGG or other controls.

I've just tried it on sample clip from web and you really need to do it scene by scene as "one" setting didn't work well for whole demo clip at all.
This is why big boys working on good automated (or semi automated) system for HDR->SDR conversion which works per scene.

Okay, will try it out. A little while ago I had a same issue with a UHD blu-ray as source. Looks like a similar issue. Used madVR to 'fix' it, but that's not an option in this case.