Samsung NX11 SRW black point inaccuracy

Observed behavior:

I've noticed that high ISO (>=800) SRW images from my NX11 gain a red tint when imported into darktable. Through closer inspection, I determined that the raw black / white point module was receiving incorrect black levels.

In darktable:

• File _0285.SRW, ISO 400, shutter 1/40 has black levels set to 5 5 7 7.
• File _0287.SRW, ISO 800, shutter 1/160 has the levels set to 24 24 0 0.

This results in _0287.SRW gaining a red tint. Setting the black levels based on exiftool's WB_RGGBLevelsBlack results in a much more color-accurate image, very similar in appearance to (if not the same as) the camera's preview.

For comparison, here are the levels read by exiftool:

$ exiftool -ISO -Samsung:WB_RGGBLevelsBlack _SAM0285.SRW
ISO                             : 400
WB RGGB Levels Black            : 2 2 2 2

$ exiftool -ISO -Samsung:WB_RGGBLevelsBlack _SAM0287.SRW
ISO                             : 800
WB RGGB Levels Black            : 14 13 13 14

The NX11 definition in cameras.xml:

<Camera make="SAMSUNG" model="NX11">
	<ID make="Samsung" model="NX11">Samsung NX11</ID>
	<CFA width="2" height="2">
		<Color x="0" y="0">BLUE</Color>
		<Color x="1" y="0">GREEN</Color>
		<Color x="0" y="1">GREEN</Color>
		<Color x="1" y="1">RED</Color>
	</CFA>
	<Crop x="17" y="8" width="4602" height="3068"/>
	<Sensor black="0" white="4095"/>
	<BlackAreas>
		<Vertical x="0" width="8"/>
	</BlackAreas>
	<ColorMatrices>
		<ColorMatrix planes="3">
			<ColorMatrixRow plane="0">10332 -3234 -1168</ColorMatrixRow>
			<ColorMatrixRow plane="1">-6111 14639 1520</ColorMatrixRow>
			<ColorMatrixRow plane="2">-1352 2647 8331</ColorMatrixRow>
		</ColorMatrix>
	</ColorMatrices>
</Camera>

_SAM0287.SRW with levels 14 13 13 14 (exiftool), color correct

_SAM0287.SRW with levels 24 24 0 0 (rawspeed), visible red tint

Expected behavior:

Black levels should match the camera’s calibration, as stored in WB_RGGBLevelsBlack.

Steps to reproduce:

• Obtain SRW files from a Samsung NX11 shot at different ISOs.
• Open them in darktable with default settings.
• Inspect the “raw black/white point” module: note the per‑channel black levels.
• Compare with exiftool -Samsung:WB_RGGBLevelsBlack

Environment:
darktable version: 5.4.1
OS: Fedora Linux 44 (KDE Plasma Desktop Edition) x86_64
Kernel: Linux 7.1.9-200.fc44.x86_64
Sample files: https://drive.proton.me/urls/8DNJB9MK1R#Tmgm7FfR51jg

Start with the Samsung NX11 entry in cameras.xml and inspect how the raw black/white point module obtains its per-channel levels for the supplied SRW files. Use the ISO 400 and ISO 800 samples with exiftool -Samsung:WB_RGGBLevelsBlack, then verify that darktable receives matching levels and no longer shows the red tint.