lcms: improve black point handling (especially BT.1886)

First of all, black point compensation is now on by default. This is
really rather harmless and only improves the result (where "improvement"
means "less black clipping").

Second, this adds an option to limit the ICC profile's contrast, which
helps for untagged matrix profiles that are implicitly black scaled even
in colorimetric intent. (Note that this relies on BPC being enabled to
work properly, which is why the two changes are tied together)

Third, this uses the LittleCMS built in black point estimator instead of
relying on the presence of accurate A2B tables. This also checks tags
and does some amounts of noise elimination.

If the option is unspecified and the profile is missing black point
information, print a warning instructing the user to set the option, and
fall back to 1000 otherwise.

1 files changed, 1 insertions, 0 deletions

diff --git a/video/out/opengl/lcms.h b/video/out/opengl/lcms.h
index ee2a48b59c..4e0a18c3d2 100644
--- a/video/out/opengl/lcms.h
+++ b/video/out/opengl/lcms.h
@@ -13,6 +13,7 @@ struct mp_icc_opts {
     char *cache_dir;
     char *size_str;
     int intent;
+    int contrast;
 };
 
 struct lut3d;