Zirconium Cross Linux From Scratch - AArch64 Version r1.0-wip-systemd

Chapter 9. System Configuration

9.26. libpng-1.6.55

9.26.1. Introduction to libpng

The libpng package contains libraries used by other programs for reading and writing PNG files. The PNG format was designed as a replacement for GIF and, to a lesser extent, TIFF, with many improvements and extensions and lack of patent problems.

Approximate build time: 0.5 SBU (with tests)
Required disk space: 16 MB (with tests)
Additional Downloads: https://www.trak4.com/zirconium/libpng-1.6.55-apng.patch
SHA256 Sum: ac91f0c374b89c8bf37b573cc27aa4f57b33e94d8e4b2ab2df494597bdd6fb99
[Note]

Note

Recommended patch to include animated png functionality in libpng (required to use the system libpng in Firefox, Seamonkey, and Thunderbird)

9.26.2. Installation of libpng

If you want to patch libpng to support apng files, apply it here: 

patch -Np1 -i ../libpng-1.6.55-apng.patch

Prepare libpng by running the following commands: 

./configure --prefix=/usr --disable-static

Compile the package: 

make

To test the results, issue: 

make check

Now, Install the package: 

make install

mkdir -v /usr/share/doc/libpng-1.6.55
cp -v README libpng-manual.txt /usr/share/doc/libpng-1.6.55

9.26.3. Command Explanations

--disable-static: This switch prevents installation of static versions of the libraries.

9.26.4. Contents

Installed Programs: libpng-config (symlink), libpng16-config, pngfix and png-fix-itxt
Installed Libraries: libpng.so
Installed Directories: /usr/include/libpng16 and /usr/share/doc/libpng-1.6.55

Short Descriptions

pngfix

tests, optimizes and optionally fixes the zlib header in PNG files. Optionally, when fixing, strips ancillary chunks from the file

png-fix-itxt

fixes PNG files that have an incorrect length field in the iTXt chunks

libpng-config

is a shell script that provides configuration information for applications wanting to use libpng

libpng.so

contain routines used to create and manipulate PNG format graphics files