RPU File Size After Using Editor

[patrickenfuego]

Not sure if this is expected or I'm using the tool wrong. I've been using the editor subcommand to edit RPU files to fix incorrect L6 metadata after extraction and I've noticed that the edited file is ~4-10 MB smaller than the extracted file.

I pipe an MKV file via ffmpeg to dovi_tool using mode 0 with --crop, then create a json file similar to the following:

{
  "mode": 2,
  "remove_mapping": true,
  "min_pq": 62,
  "max_pq": 3696,
  "active_area": {
    "crop": true,
    "edits": {
      "all": 0
    }
  },
  "level6": {
    "max_display_mastering_luminance": 4000,
    "min_display_mastering_luminance": 50,
    "max_content_light_level": 500,
    "max_frame_average_light_level": 200
  }
}

Then edit:

dovi_tool editor -i rpu.bin -j edited.json -o rpu_edited.bin

My assumptions are that a profile 8.1 RPU simply has less metadata compared to a profile 7 RPU after dropping the enhancement layer or --crop is reducing the size (someone else mentioned that here), but I figured I'd ask in case I'm using it incorrectly. Cheers.