How to add camera support to libraw/darktable?

Software darktable
,
1

I was trying to add support for the R5mk2 into libraw and darktable but I must miss a part. Here’s what I did so far.

Adding the colormatrix from Adobe into colordata.cpp:

	{ LIBRAW_CAMERAMAKER_Canon, "EOS R5 Mark II", 0, 0,
	  { 9396,-2598,-1207,-4408,12296,2369,-505,1575,6077 } },

and adding the cameraID to libraw_cameraids.h:

#define CanonID_EOS_R5m2          (0x80000000ULL + 0x496ULL)

adding the camera to canon.cpp in the FF part:

           || (id == CanonID_EOS_R5)
           || (id == CanonID_EOS_R5m2)

adding it to cameralist.cpp:

	"Canon EOS R5",
	"Canon EOS R5 Mark II",

and to normalize_model.cpp:

      { CanonID_EOS_R5,            "EOS R5"},
      { CanonID_EOS_R5m2,          "EOS R5 Mark II"},

in darktable I changed cameras.xml:

	<Camera make="Canon" model="Canon EOS R5m2" supported="no">
		<ID make="Canon" model="EOS R5 Mark II">Canon EOS R5 Mark II</ID>

and imageio_libraw.c:

  {
    .exif_make = "Canon",
    .exif_model = "Canon EOS R5m2",
    .clean_make = "Canon",
    .clean_model = "EOS R5 Mark II",
    .clean_alias = "EOS R5 Mark II"
  },

Finally to get rid of the wb warning I copy pasted another one into wb_presets (will be done as soon as i have the camera myself as well as the noiseprofile). But darktable still says it cant find the color matrix for the raw file I downloaded. Did I miss something or are the preproduction raw files just a little bit different to the final ones?

2

Firmware 1.0.0 files also don’t seem to work with this.

Files from Canon EOS R5 MK II – Google Drive

3

Ok as ColorDataSubVer seems to be 64, it most likely needs a new case here:

    case 3656: // R5, R6; ColorDataSubVer: 33
      imCanon.ColorDataVer = 10;
      AsShot_Auto_MeasuredWB(0x0055);
      CR3_ColorData(0x0055);
      break;

    case 3973: // R3; ColorDataSubVer: 34
    case 3778: // R6 Mark II, R7, R8, R10, R50; ColorDataSubVer: 48
      imCanon.ColorDataVer = 11;
      AsShot_Auto_MeasuredWB(0x0069);

      fseek(ifp, save1 + ((0x0069+0x0064) << 1), SEEK_SET);
      Canon_WBpresets(2, 12);
      fseek(ifp, save1 + ((0x0069+0x00c3) << 1), SEEK_SET);
      Canon_WBCTpresets(0);
      offsetChannelBlackLevel2 = save1 + ((0x0069+0x0102) << 1);
      offsetChannelBlackLevel  = save1 + ((0x0069+0x0213) << 1);
      offsetWhiteLevels        = save1 + ((0x0069+0x0217) << 1);
      break;

anyone here willing or has the time to teach me how to find the respective bit positions in the raw file? I guess it’s not that hard but my c++ skills are basically nonexistent.

Ok case seems to be 4528 and just putting it like the R3 does not work so bit positions are likely somewhere else

4

Ok getting closer. Colors work fine for me, although the white value is not the specular one although I am addressing the correct field

case 4528: // R5 Mark II; ColorDataSubVer: 64
      imCanon.ColorDataVer = 12;
      AsShot_Auto_MeasuredWB(0x0069);     

      //fseek(ifp, save1 + ((0x0069+0x0064) << 1), SEEK_SET);
      //Canon_WBpresets(2, 12);
      //fseek(ifp, save1 + ((0x0069+0x00c3) << 1), SEEK_SET);
      //Canon_WBCTpresets(0);
      offsetChannelBlackLevel2 = save1 + (0x017f << 1); 
      offsetChannelBlackLevel  = save1 + (0x0290 << 1); 
      offsetWhiteLevels        = save1 + (0x0294 << 1); 
      break;

edit: needs to be 294 for it to find the correct white point (reading the few lines afterwards would have helped figuring this out :wink: )

edit2: for WBpresets and WBCTpresets I’m still lost, as exiftool lists all tags as unknown so far unfortunately

Also if someone would explain the 0x0069+0x0102 notation it would be nice. For me this kinda unnecessarily obfuscates the correct address but I am obviously missing something here. Most likely written as offset to the measured WB field.

edit: Changed ColorDateVer back to 11
edit2: Changed ColorDateVer back to 12 according to Add Canon R5m2 Colorinfo

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5

ok, with exiftool supprting the new tags it’s:

    case 4528: // R5 Mark II; ColorDataSubVer: 64
      imCanon.ColorDataVer = 12;
      AsShot_Auto_MeasuredWB(0x0069);     

      fseek(ifp, save1 + (0x006e << 1), SEEK_SET);
      Canon_WBpresets(2, 12);
      fseek(ifp, save1 + (0x0140 << 1), SEEK_SET);
      Canon_WBCTpresets(0);
      offsetChannelBlackLevel2 = save1 + (0x017f << 1); 
      offsetChannelBlackLevel  = save1 + (0x0290 << 1); 
      offsetWhiteLevels        = save1 + (0x0294 << 1); 
      break;
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6

I wrote a short blog post on the process if anyone is interested: Adding new camera support in darktable / LibRaw / ExifTool – Pandas Welt

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7

Thank you @piratenpanda. Your blog post works for me.

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