Doing this in FFmpegVideoDecoder meant that the fallback to BT.709 with
unspecified transfer characteristics was taking precedence. Instead of
overriding unspecified to sRGB there, change the switch statement in
ColorSpace::from_cicp() so that the unspecified fallback and override
both live in the same place.
This should fix the contrast on a lot of YouTube videos.
Note that this now also affects images, which is consistent with
Chromium.
ImageDecoder itself can check the matrix coefficients and range flag
instead. In the future, ImageDecoder should probably convert its images
into RGB color space using the same solution as for video.
A malicious IPC peer could claim an enormous color space size, causing
OOM when we try to allocate a buffer. Add a 1 MiB limit since color
space profiles shouldn't be anywhere near that large.
Also validate that SkColorSpace::Deserialize() actually succeeded
before using the result.
Skia's SkColorSpace::Make() doesn't seem to like ICC v2 profiles
containing table-based L* transfer curves. Now we use
skcms_ApproximateCurve() to convert these tables to parametric curves
that Skia supports in case Skia's SkColorSpace::Make() fails.
This adds all parameters supported by skia by default. Supporting the
other parameters would just be a matter of defining the constants, but
that's work for another time.
This introduces a new API in ImageDecoderPlugins that allow an image
decoder to return a CICP struct. Also, we use this API in
ImageDecoder::color_space() to create a color space corresponding to
these CICP.
This patch introduces the `Gfx::ColorSpace` class, this is basically a
serializable wrapper for skia's SkColorSpace. Creation of the instances
of this class (and thus ICC profiles parsing) is performed in the
ImageDecoder process. Then the object is serialized and sent through
IPC, to finally be handed to skia for rendering.
However, to make sure that we're not making all LibGfx's users dependent
on Skia as well, we need to ensure the `Gfx::ColorSpace` object has no
dependency on objects from Skia. To that end, the only member of the
`ColorSpace` class is the opaque `ColorSpaceImpl` struct. Though, there
is on issue with that design, the code in `DisplayListPlayer.cpp` needs
access to the underlying `sk_sp<SkColorSpace>`. It is provided by a
template function, that is only specialized for this type.
Doing this work allows us to pass the following WPT tests:
- https://wpt.live/css/css-color/tagged-images-001.html
- https://wpt.live/css/css-color/tagged-images-003.html
- https://wpt.live/css/css-color/tagged-images-004.html
- https://wpt.live/css/css-color/untagged-images-001.html
Other test cases can also be found here:
- https://github.com/svgeesus/PNG-ICC-tests
Note that SkColorSpace support quite a limited amount of color spaces,
so color profiles like the ones in [1] or the v4 profiles in [2] are not
supported yet. In fact, SkColorSpace only accepts skcms_ICCProfile with
a linear conversion to XYZ D50.
[1] https://www.color.org/browsertest.xalter
[2] https://www.color.org/version4html.xalter
