AVIF support (#671)

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.

3 files changed, 17 insertions, 2 deletions

diff --git a/windows/Makefile.vc b/windows/Makefile.vc
index d97b22f..3fefe80 100644
--- a/windows/Makefile.vc
+++ b/windows/Makefile.vc
@@ -95,10 +95,11 @@ LIB_OBJS= \
   $(LIBGD_OBJ_DIR)\gd_crop.obj \
   $(LIBGD_OBJ_DIR)\gd_color_map.obj \
   $(LIBGD_OBJ_DIR)\gd_heif.obj \
+  $(LIBGD_OBJ_DIR)\gd_avif.obj \
   $(LIBGD_OBJ_DIR)\gd_webp.obj
 
 LIBS=kernel32.lib ole32.lib user32.lib advapi32.lib shell32.lib ws2_32.lib Dnsapi.lib Gdi32.Lib
-LIBS_GD=libjpeg_a.lib freetype_a.lib libpng_a.lib libiconv_a.lib  zlib_a.lib libheif_a.lib libwebp_a.lib libxpm_a.lib libtiff.lib
+LIBS_GD=libjpeg_a.lib freetype_a.lib libpng_a.lib libiconv_a.lib  zlib_a.lib libheif_a.lib libwebp_a.lib libxpm_a.lib libavif_a.lib libtiff.lib
 
 PROG_EXES= \
 	$(LIBGD_OBJ_DIR)\gdcmpgif.exe \
@@ -135,11 +136,13 @@ CFLAGS= $(CFLAGS) \
        /DHAVE_FT2BUILD_H=1\
        /DHAVE_GD_H=1\
        /DHAVE_ICONV_H=1\
+       /DHAVE_LIBAVIF=1\
        /DHAVE_LIBFREETYPE=1\
        /DHAVE_LIBJPEG=1\
        /DHAVE_LIBPNG=1\
        /DHAVE_LIBWEBP=1\
        /DHAVE_LIBHEIF=1\
+       /DHAVE_LIBAVIF=1\
        /DHAVE_LIBZ=1\
        /DHAVE_LIBXPM=1\
        /DHAVE_LIBTIFF=1\
@@ -186,6 +189,9 @@ make_dirs:
 	@echo #ifndef HAVE_ICONV_H>> $(GD_CONFIG_H)
 	@echo #define HAVE_ICONV_H>> $(GD_CONFIG_H)
 	@echo #endif>> $(GD_CONFIG_H)
+	@echo #ifndef HAVE_LIBAVIF>> $(GD_CONFIG_H)
+	@echo #define HAVE_LIBAVIF>> $(GD_CONFIG_H)
+	@echo #endif>> $(GD_CONFIG_H)
 	@echo #ifndef HAVE_LIBFREETYPE>> $(GD_CONFIG_H)
 	@echo #define HAVE_LIBFREETYPE>> $(GD_CONFIG_H)
 	@echo #endif>> $(GD_CONFIG_H)
@@ -201,6 +207,9 @@ make_dirs:
 	@echo #ifndef HAVE_LIBHEIF>> $(GD_CONFIG_H)
 	@echo #define HAVE_LIBHEIF>> $(GD_CONFIG_H)
 	@echo #endif>> $(GD_CONFIG_H)
+	@echo #ifndef HAVE_LIBAVIF>> $(GD_CONFIG_H)
+	@echo #define HAVE_LIBAVIF>> $(GD_CONFIG_H)
+	@echo #endif>> $(GD_CONFIG_H)
 	@echo #ifndef HAVE_LIBZ>> $(GD_CONFIG_H)
 	@echo #define HAVE_LIBZ>> $(GD_CONFIG_H)
 	@echo #endif>> $(GD_CONFIG_H)
diff --git a/windows/Makefiletest.vc b/windows/Makefiletest.vc
index 827a4e7..6e5d598 100644
--- a/windows/Makefiletest.vc
+++ b/windows/Makefiletest.vc
@@ -1,5 +1,10 @@
 TESTS=bmp\bmp_im2im \
 bmp\bmp_null \
+avif\avif_ptr_double_free \
+avif\avif_im2im \
+avif\avif_null \
+avif\compare_avif_to_png \
+avif\bad_input \
 freetype\bug00132 \
 gd\gd_im2im \
 gd\gd_null \
diff --git a/windows/msys/Makefile b/windows/msys/Makefile
index 8c5d380..d183ac2 100644
--- a/windows/msys/Makefile
+++ b/windows/msys/Makefile
@@ -98,7 +98,8 @@ gd_topal.c gd_wbmp.c gdcache.c gdfontg.c gdfontl.c gdfontmb.c		\
 gdfonts.c gdfontt.c gdft.c gdhelpers.c gdkanji.c gdtables.c gdxpm.c	\
 wbmp.c gd_filter.c gd_nnquant.c gd_rotate.c gd_matrix.c				\
 gd_interpolation.c gd_crop.c gd_webp.c gd_heif.c gd_tiff.c gd_tga.c	\
-gd_bmp.c gd_xbm.c gd_color_match.c gd_version.c gd_filename.c
+gd_bmp.c gd_xbm.c gd_color_match.c gd_version.c gd_filename.c \
+gd_avif.c
 
 OBJ=$(SRC:.c=.o)