Instead of copying the options around... just don't. video.c now has
full control over when options are updated. (It still gets notified from
outside, but it decides when the updated options are copied: when
m_config_cache_update() is called.) So there's no need for tricky
stuff, and it can be simplified a bit.
Also change lcms.c. We could do it like video.c, and get the options
from the global config store. But it seems simpler to just provide a
pointer to an option struct, which is arbitrarily mutated from the
outside (from the perspective of lcms.c).
Commit 026b75e7 actually enabled changing icc options at runtime (via
vo_cmdline), but it didn't quite work. In particular, changing the icc-
profile option just kept the old profile, because it was cached
accordingly.
As part of this, change gl_lcms.opts from a struct to a pointer to a
struct. We properly copy it, instead of allowing possibly dangling
strings, like it was done in a working but unclean way before.
Also, reinit the whole rendering chain when the auto icc profile
changes, just like it's done when icc options are changed.
Passing the bstr thing as pointer makes no sense. Everywhere else bstr
structs are passed by value because they're so small. Only when it's
supposed to receive a return value they're not.
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.
This commit refactors the 3DLUT loading mechanism to build the 3DLUT
against the original source characteristics of the file. This allows us,
among other things, to use a real BT.1886 profile for the source. This
also allows us to actually use perceptual mappings. Finally, this
reduces errors on standard gamut displays (where the previous 3DLUT
target of BT.2020 was unreasonably wide).
This also improves the overall accuracy of the 3DLUT due to eliminating
rounding errors where possible, and allows for more accurate use of
LUT-based ICC profiles.
The current code is somewhat more ugly than necessary, because the idea
was to implement this commit in a working state first, and then maybe
refactor the profile loading mechanism in a later commit.
Fixes#2815.
