Expand sidecar params to actual values

Software darktable
1

I’m trying to analyze a large batch of xmp files, and can’t figure out how to expand the parameters.

     <rdf:li
      darktable:num="15"
      darktable:operation="temperature"
      darktable:enabled="1"
      darktable:modversion="3"
      darktable:params="ca63f53f0000803fefebcb3f0000807f"
      darktable:multi_name=""
      darktable:multi_priority="0"
      darktable:iop_order="3.0000000000000"
      darktable:blendop_version="9"
      darktable:blendop_params="gz11eJxjYGBgkGAAgRNODGiAEV0AJ2iwh+CRyscOAAdeGQQ="/>

I’ve put together a small node utility that imports @wmakeev/darkroom-xmp-tools, but that only covers 9 operations. When it works, it’s perfect:

image
image1752×642 87.4 KB

I’ve tried setting this, but no changes when I saved a new file.

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image1284×352 8.75 KB

Is there a way of getting around this compression?

Thanks,

Tac

2

That’s not compression, but encoding. You’ll need to read the C code to figure out what they are, they’re not documented as far as I know.

3

@jchnkl created a time-lapse tool that works with darktable (Annoucement of dtLapse) and had to solve this issue to do so.

Maybe you can contact him or look at the code on github.

4

I’m not a C programmer, but I’m navigating my way through the code.

So far I’ve discovered that if it begins with gz, it’s a compressed string, otherwise it’s a binary-encoded string that maps to the C struct for that operation.

Thanks for the dtLapse reference.