Drop spng from dependencies (lovell#300)

libpng, which is already included as a transitive dependency,
has seen a lot of recent improvements whilst spng has sadly
started to bit-rot.

- Adds PNG v3 spec compliance
- Allows for future possible animated PNG support
- No performance impact, most CPU time is in zlib-ng
- Reduces binary size by ~30KB

Author: lovell

THIRD-PARTY-NOTICES.md

@@ -24,7 +24,6 @@ used under the terms of the following licences:
 | libnsgif      | MIT Licence                                                                                               |
 | libpng        | [libpng License](https://github.com/pnggroup/libpng/blob/master/LICENSE)                                  |
 | librsvg       | LGPLv3                                                                                                    |
-| libspng       | [BSD 2-Clause, libpng License](https://github.com/randy408/libspng/blob/master/LICENSE)                   |
 | libtiff       | [libtiff License](https://gitlab.com/libtiff/libtiff/blob/master/LICENSE.md) (BSD-like)                   |
 | libvips       | LGPLv3                                                                                                    |
 | libwebp       | New BSD License                                                                                           |

build/posix.sh

@@ -213,13 +213,6 @@ cd ${DEPS}/png
   --disable-tools --without-binconfigs --disable-unversioned-libpng-config
 make install-strip dist_man_MANS=
 
-mkdir ${DEPS}/spng
-$CURL https://github.com/randy408/libspng/archive/v${VERSION_SPNG}.tar.gz | tar xzC ${DEPS}/spng --strip-components=1
-cd ${DEPS}/spng
-CFLAGS="${CFLAGS} -O3 -DSPNG_SSE=4" meson setup _build --default-library=static --buildtype=release --strip --prefix=${TARGET} ${MESON} \
-  -Dstatic_zlib=true -Dbuild_examples=false
-meson install -C _build --tag devel
-
 mkdir ${DEPS}/imagequant
 $CURL https://github.com/lovell/libimagequant/archive/v${VERSION_IMAGEQUANT}.tar.gz | tar xzC ${DEPS}/imagequant --strip-components=1
 cd ${DEPS}/imagequant
@@ -470,7 +463,6 @@ printf "{\n\
   \"png\": \"${VERSION_PNG}\",\n\
   \"proxy-libintl\": \"${VERSION_PROXY_LIBINTL}\",\n\
   \"rsvg\": \"${VERSION_RSVG}\",\n\
-  \"spng\": \"${VERSION_SPNG}\",\n\
   \"tiff\": \"${VERSION_TIFF}\",\n\
   \"vips\": \"${VERSION_VIPS}\",\n\
   \"webp\": \"${VERSION_WEBP}\",\n\

check-latest-versions.sh

@@ -47,7 +47,6 @@ version_latest "pixman" "$VERSION_PIXMAN" "3648"
 version_latest "png" "$VERSION_PNG" "1705"
 version_latest "proxy-libintl" "$VERSION_PROXY_LIBINTL" "frida/proxy-libintl"
 version_latest "rsvg" "$VERSION_RSVG" "5420" "unstable"
-version_latest "spng" "$VERSION_SPNG" "randy408/libspng"
 version_latest "tiff" "$VERSION_TIFF" "1738"
 version_latest "vips" "$VERSION_VIPS" "5097"
 version_latest "webp" "$VERSION_WEBP" "1761"

versions.properties

@@ -20,7 +20,6 @@ VERSION_PIXMAN=0.46.4
 VERSION_PNG=1.6.51
 VERSION_PROXY_LIBINTL=0.5
 VERSION_RSVG=2.61.3
-VERSION_SPNG=0.7.4
 VERSION_TIFF=4.7.1
 VERSION_VIPS=8.17.3
 VERSION_WEBP=1.6.0