JPEG: c-implementation

A C-based jpeg baseline encoder & decoder

Prerequirements

• use bitmap library to access bmp file.
  • this library is written in c++, so we should compile whole project using g++

How to use

Compile

• use makefile to compile all

$ make

• and you can specific decoder or encoder, even clean (delete)

$ make encoder # g++ -o encoder encoder.c -O3
$ make decoder # g++ -o decoder decoder.c -O3
$ make clean # rm decoder encoder

• or compile with g++

$ g++ -o decoder decoder.c -O3
$ g++ -o encoder encoder.c -O3

command example

• encoder: NOTICE that input file should be bmp, output file should be jpg
  • output file is optional, if you don't specify it, it would be image.jpg

$ ./encoder <input file> [output file]

• decoder: NOTICE that input file should be jpg, output file should be bmp
  • output file is optional, if you don't specify it, it would be image.bmp

$ ./decoder <input file> [output file]

• NOTICE that $ stands for command prompt.

environments

• already tested on my macOS and NTU CSIE server (Arch Linux), so any FreeBSD or Linux environments should be fine.
• more detail below:

$ g++ -v
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include/c++/4.2.1
Apple LLVM version 10.0.1 (clang-1001.0.46.4)
Target: x86_64-apple-darwin18.5.0

r07922009@linux9 [~/JPEG] g++ -v
使用內建 specs。
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/8.3.0/lto-wrapper
目的：x86_64-pc-linux-gnu
配置為：/build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp --enable-cet=auto
執行緒模型：posix
gcc version 8.3.0 (GCC)

Author&LICENSE

MIT @kuoteng, 2019