How to compile Lepton (JPEG lossless recompressor by Dropbox) without autotools

This blog post explains how to compile Lepton, the recently released JPEG lossless recompressor by Dropbox without autotools on Linux.

You'll need a fairly recent C++ compiler with the development libraries installed. g++-4.4 is too old, g++-4.8 is good enough.

Compile with the following command (without the leading $):

$ git clone https://github.com/dropbox/lepton
$ cd lepton
$ # Optional: git reset --hard e3f6c46502d958aaba17fbe7c218f8ce2b8b3f48
$ g++ -std=c++0x -W -Wall -Wextra -Wno-unused-parameter -Wno-write-strings \
    -msse4.1 \
    -o lepton \
    -fno-exceptions -fno-rtti \
    -s -O2 \
    -DGIT_REVISION=\"fake\" \
    -I./src/vp8/decoder \
    -I./src/vp8/encoder \
    -I./src/vp8/model \  
    -I./src/vp8/util \ 
    dependencies/md5/md5.c \
    src/io/MemMgrAllocator.cc \
    src/io/MemReadWriter.cc \  
    src/io/Seccomp.cc \
    src/io/Zlib0.cc \  
    src/io/ZlibCompression.cc \
    src/io/ioutil.cc \
    src/lepton/bitops.cc \
    src/lepton/fork_serve.cc \
    src/lepton/idct.cc \
    src/lepton/jpgcoder.cc \
    src/lepton/lepton_codec.cc \
    src/lepton/recoder.cc \
    src/lepton/simple_decoder.cc \
    src/lepton/simple_encoder.cc \
    src/lepton/socket_serve.cc \  
    src/lepton/thread_handoff.cc \
    src/lepton/uncompressed_components.cc \
    src/lepton/validation.cc \
    src/lepton/vp8_decoder.cc \
    src/lepton/vp8_encoder.cc \
    src/vp8/decoder/boolreader.cc \
    src/vp8/decoder/decoder.cc \   
    src/vp8/encoder/boolwriter.cc \
    src/vp8/encoder/encoder.cc \   
    src/vp8/model/JpegArithmeticCoder.cc \
    src/vp8/model/model.cc \
    src/vp8/model/numeric.cc \
    src/vp8/util/billing.cc \ 
    src/vp8/util/debug.cc \  
    src/vp8/util/generic_worker.cc \
    src/vp8/util/memory.cc \
    -lz \
    -lpthread \
;

$ ./lepton --help

It works both on i386 (force it with -m32) and amd64 (force it with -m64) architectures. Other architectures are not supported, because Lepton uses the SSE4.1 CPU instructions.

It also works with -std=c++11, but it doesn't work with -std=c++98.

Lepton also has a copy of zlib embedded, you can compile it with gcc instead of g++, and use it instead of -lz.

These instructions were tested and found working with the following version of Lepton:

$ git rev-parse HEAD
# e3f6c46502d958aaba17fbe7c218f8ce2b8b3f48