libheif versions that came before 1.9.0 don't support changing the output image chroma.
I did not notice that and it resulted with tests failures across other OSes that don't have
a much newer libheif.
See #678. Supersedes #685.
Demand for AVIF support on the web is growing, as the word gets out
about this new file format which allows higher-quality encoding at
smaller sizes. Core contributors to major open-source CMSs are
interested in auto-generating AVIF images! They've been simply
waiting for support to appear in libgd.
This PR aims to meet the growing demand, and to help bring smaller,
more beautiful images to more of the web - to sites created by
experienced developers and CMS users alike.
This PR adds support by incorporating libavif in addition to the
existing libheif support. It's generally felt that libavif has
more complete support for the AVIF format. libavif is also used
by the Chromium project and squoosh.app.
In this PR, I've endeavored to incorporate the latest research into
best practices for AVIF encoding - not just for default quantizer
values, but also an algorithm for determining the number of
horizontal tiles, vertical tiles, and threads.
Fixes#557.
Ensure that a GIF without any Global or Local color tables is still
decoded by libgd.
GIF89a spec indicates conforming image files need not have
Global or Local color tables at all.
Spec recommends creating custom color map in that situation, and
that at least Black+White as first two entries, to ensure B&W images
are decoded.
Some commonly used single-pixel GIFs found around the web are
undecoded by libgd otherwise. Test case has been included.
References:
https://www.w3.org/Graphics/GIF/spec-gif89a.txthttp://probablyprogramming.com/2009/03/15/the-tiniest-gif-ever
With the adoption of AVIF by Firefox and Chromium based browsers (still
in experimental phase), the newer incorporation of HEIF by Canon and Sony
in their cameras and the newer support of both of them in modern software
like ImageMagick, GIMP and Krita, `gd` haven't seen any endorsement for
the formats up until this PR.
Reading and writing is done by `libheif`, with functionality for chroma
subsampling (for now `4:2:0`, `4:2:2` and `4:4:4`), quality (with new
`200` for lossless) and compression (whether `HEVC` or `AV1`) selection.
This was tested with `libheif` version `1.11.0` in my Solus machine.
Also, fixes both #395 and #557.
We change the return type of `textLayout()` to `ssize_t`, and signal
failure by returning `-1`, so that laying out an empty string is no
longer handled as failure. We make sure that no overflow occurs,
assuming that all `int` values can be fully represented as `ssize_t`.
@pierrejoye has implemented opendir, closedir and readdir in readdir.c, which is only used under windows platform. These functions are enabled by modifiying the tests/gdTest/CMakeLists.txt
Pierre Joye
Adam Silverstein
Remi Collet
Martin Reboredo
Mike Frysinger
Ben Morss
az6667
wilson chen
Christoph M. Becker
Fábio Cabral Pacheco