libjpeg移植到dm368平台

库版本：
jpegsrc.v6b.tar.gz
下载地址：
http://www.ijg.org/files/jpegsrc.v6b.tar.gz
编译器版本：
arm-none-linux-gnueabi-gcc

代码成功移植到dm368平台。

第一步，libpeg移植具体操作步骤：

step1、解压库源码包
tar -xzvf jpegsrc.v6b.tar.gz
会在同目录下面生成一个jpeg-6b文件夹

step2、进入到安装目录，运行./configure命令完成必要配置
具体命令和必要参数：

./configure CC=/opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi-gcc LD=/opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi-gcc-ld --prefix=/home/davinci/jpeg_arm/ --exec-prefix=/home/davinci/jpeg_arm/ --enable-shared --enable-static --host=/opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi

参数介绍：
CC：代表交叉编译程序
LD：代表交叉编译链接程序
prefix：表示执行sudo make install以后头文件、库文件和帮助文档安装的目录
exec-prefix:和上一个总是一样的
enable-shared和enabled-static：表示支持静态链接和动态链接
host：一般就是去CC和LD的公共部分

执行完这条配置命令以后，完成的Makefile的配置。下面我把我自己的执行前后的Makefile贴出来对比一下：

执行之前：

# Generated automatically from makefile.cfg by configure.# Makefile for Independent JPEG Group's software# makefile.cfg is edited by configure to produce a custom Makefile.# Read installation instructions before saying "make" !!# For compiling with source and object files in different directories.srcdir = .# Where to install the programs and man pages.prefix = exec_prefix = bindir = $(exec_prefix)/binlibdir = $(exec_prefix)/libincludedir = $(prefix)/includebinprefix =manprefix =manext = 1mandir = $(prefix)/man/man$(manext)# The name of your C compiler:CC= # You may need to adjust these cc options:CFLAGS= -O2  -I$(srcdir)# Generally, we recommend defining any configuration symbols in jconfig.h,# NOT via -D switches here.# However, any special defines for ansi2knr.c may be included here:ANSI2KNRFLAGS= # Link-time cc options:LDFLAGS= # To link any special libraries, add the necessary -l commands here.LDLIBS= # If using GNU libtool, LIBTOOL references it; if not, LIBTOOL is empty.LIBTOOL = ./libtool# $(O) expands to "lo" if using libtool, plain "o" if not.# Similarly, $(A) expands to "la" or "a".O = loA = la# Library version ID; libtool uses this for the shared library version number.# Note: we suggest this match the macro of the same name in jpeglib.h.JPEG_LIB_VERSION = 62# Put here the object file name for the correct system-dependent memory# manager file.  For Unix this is usually jmemnobs.o, but you may want# to use jmemansi.o or jmemname.o if you have limited swap space.SYSDEPMEM= jmemnobs.$(O)# miscellaneous OS-dependent stuffSHELL= /bin/sh# linkerLN= $(LIBTOOL) --mode=link $(CC)# file deletion commandRM= rm -f# directory creation commandMKDIR= mkdir# library (.a) file creation commandAR= ar rc# second step in .a creation (use "touch" if not needed)AR2= ranlib# installation programINSTALL= /usr/bin/install -cINSTALL_PROGRAM= $(LIBTOOL) --mode=install ${INSTALL}INSTALL_LIB= $(LIBTOOL) --mode=install ${INSTALL}INSTALL_DATA= ${INSTALL} -m 644# End of configurable options.# source files: JPEG library properLIBSOURCES= jcapimin.c jcapistd.c jccoefct.c jccolor.c jcdctmgr.c jchuff.c \        jcinit.c jcmainct.c jcmarker.c jcmaster.c jcomapi.c jcparam.c \        jcphuff.c jcprepct.c jcsample.c jctrans.c jdapimin.c jdapistd.c \        jdatadst.c jdatasrc.c jdcoefct.c jdcolor.c jddctmgr.c jdhuff.c \        jdinput.c jdmainct.c jdmarker.c jdmaster.c jdmerge.c jdphuff.c \        jdpostct.c jdsample.c jdtrans.c jerror.c jfdctflt.c jfdctfst.c \        jfdctint.c jidctflt.c jidctfst.c jidctint.c jidctred.c jquant1.c \        jquant2.c jutils.c jmemmgr.c# memmgr back ends: compile only one of these into a working librarySYSDEPSOURCES= jmemansi.c jmemname.c jmemnobs.c jmemdos.c jmemmac.c# source files: cjpeg/djpeg/jpegtran applications, also rdjpgcom/wrjpgcomAPPSOURCES= cjpeg.c djpeg.c jpegtran.c rdjpgcom.c wrjpgcom.c cdjpeg.c \        rdcolmap.c rdswitch.c transupp.c rdppm.c wrppm.c rdgif.c wrgif.c \        rdtarga.c wrtarga.c rdbmp.c wrbmp.c rdrle.c wrrle.cSOURCES= $(LIBSOURCES) $(SYSDEPSOURCES) $(APPSOURCES)# files included by source filesINCLUDES= jchuff.h jdhuff.h jdct.h jerror.h jinclude.h jmemsys.h jmorecfg.h \        jpegint.h jpeglib.h jversion.h cdjpeg.h cderror.h transupp.h# documentation, test, and support filesDOCS= README install.doc usage.doc cjpeg.1 djpeg.1 jpegtran.1 rdjpgcom.1 \        wrjpgcom.1 wizard.doc example.c libjpeg.doc structure.doc \        coderules.doc filelist.doc change.logMKFILES= configure makefile.cfg makefile.ansi makefile.unix makefile.bcc \        makefile.mc6 makefile.dj makefile.wat makefile.vc makelib.ds \        makeapps.ds makeproj.mac makcjpeg.st makdjpeg.st makljpeg.st \        maktjpeg.st makefile.manx makefile.sas makefile.mms makefile.vms \        makvms.optCONFIGFILES= jconfig.cfg jconfig.bcc jconfig.mc6 jconfig.dj jconfig.wat \        jconfig.vc jconfig.mac jconfig.st jconfig.manx jconfig.sas \        jconfig.vmsCONFIGUREFILES= config.guess config.sub install-sh ltconfig ltmain.shOTHERFILES= jconfig.doc ckconfig.c ansi2knr.c ansi2knr.1 jmemdosa.asmTESTFILES= testorig.jpg testimg.ppm testimg.bmp testimg.jpg testprog.jpg \        testimgp.jpgDISTFILES= $(DOCS) $(MKFILES) $(CONFIGFILES) $(SOURCES) $(INCLUDES) \        $(CONFIGUREFILES) $(OTHERFILES) $(TESTFILES)# library object files common to compression and decompressionCOMOBJECTS= jcomapi.$(O) jutils.$(O) jerror.$(O) jmemmgr.$(O) $(SYSDEPMEM)# compression library object filesCLIBOBJECTS= jcapimin.$(O) jcapistd.$(O) jctrans.$(O) jcparam.$(O) \        jdatadst.$(O) jcinit.$(O) jcmaster.$(O) jcmarker.$(O) jcmainct.$(O) \        jcprepct.$(O) jccoefct.$(O) jccolor.$(O) jcsample.$(O) jchuff.$(O) \        jcphuff.$(O) jcdctmgr.$(O) jfdctfst.$(O) jfdctflt.$(O) \        jfdctint.$(O)# decompression library object filesDLIBOBJECTS= jdapimin.$(O) jdapistd.$(O) jdtrans.$(O) jdatasrc.$(O) \        jdmaster.$(O) jdinput.$(O) jdmarker.$(O) jdhuff.$(O) jdphuff.$(O) \        jdmainct.$(O) jdcoefct.$(O) jdpostct.$(O) jddctmgr.$(O) \        jidctfst.$(O) jidctflt.$(O) jidctint.$(O) jidctred.$(O) \        jdsample.$(O) jdcolor.$(O) jquant1.$(O) jquant2.$(O) jdmerge.$(O)# These objectfiles are included in libjpeg.aLIBOBJECTS= $(CLIBOBJECTS) $(DLIBOBJECTS) $(COMOBJECTS)# object files for sample applications (excluding library files)COBJECTS= cjpeg.$(O) rdppm.$(O) rdgif.$(O) rdtarga.$(O) rdrle.$(O) \        rdbmp.$(O) rdswitch.$(O) cdjpeg.$(O)DOBJECTS= djpeg.$(O) wrppm.$(O) wrgif.$(O) wrtarga.$(O) wrrle.$(O) \        wrbmp.$(O) rdcolmap.$(O) cdjpeg.$(O)TROBJECTS= jpegtran.$(O) rdswitch.$(O) cdjpeg.$(O) transupp.$(O)all:  libjpeg.$(A) cjpeg djpeg jpegtran rdjpgcom wrjpgcom# Special compilation rules to support ansi2knr and libtool..SUFFIXES: .lo .la# How to compile with libtool..c.lo:    $(LIBTOOL) --mode=compile $(CC) $(CFLAGS) -c $(srcdir)/$*.c# How to use ansi2knr, when not using libtool.# .c.o:#   ./ansi2knr $(srcdir)/$*.c knr/$*.c#   $(CC) $(CFLAGS) -c knr/$*.c#   $(RM) knr/$*.c# How to use ansi2knr AND libtool.# .c.lo:#   ./ansi2knr $(srcdir)/$*.c knr/$*.c#   $(LIBTOOL) --mode=compile $(CC) $(CFLAGS) -c knr/$*.c#   $(RM) knr/$*.cansi2knr: ansi2knr.c    $(CC) $(CFLAGS) $(ANSI2KNRFLAGS) -o ansi2knr $(srcdir)/ansi2knr.c    $(MKDIR) knr# the library:# without libtool:libjpeg.a:  $(LIBOBJECTS)    $(RM) libjpeg.a    $(AR) libjpeg.a  $(LIBOBJECTS)    $(AR2) libjpeg.a# with libtool:libjpeg.la:  $(LIBOBJECTS)    $(LIBTOOL) --mode=link $(CC) -o libjpeg.la $(LIBOBJECTS) \        -rpath $(libdir) -version-info $(JPEG_LIB_VERSION)# sample programs:cjpeg: $(COBJECTS) libjpeg.$(A)    $(LN) $(LDFLAGS) -o cjpeg $(COBJECTS) libjpeg.$(A) $(LDLIBS)djpeg: $(DOBJECTS) libjpeg.$(A)    $(LN) $(LDFLAGS) -o djpeg $(DOBJECTS) libjpeg.$(A) $(LDLIBS)jpegtran: $(TROBJECTS) libjpeg.$(A)    $(LN) $(LDFLAGS) -o jpegtran $(TROBJECTS) libjpeg.$(A) $(LDLIBS)rdjpgcom: rdjpgcom.$(O)    $(LN) $(LDFLAGS) -o rdjpgcom rdjpgcom.$(O) $(LDLIBS)wrjpgcom: wrjpgcom.$(O)    $(LN) $(LDFLAGS) -o wrjpgcom wrjpgcom.$(O) $(LDLIBS)# Installation rules:install: cjpeg djpeg jpegtran rdjpgcom wrjpgcom install-lib    $(INSTALL_PROGRAM) cjpeg $(bindir)/$(binprefix)cjpeg    $(INSTALL_PROGRAM) djpeg $(bindir)/$(binprefix)djpeg    $(INSTALL_PROGRAM) jpegtran $(bindir)/$(binprefix)jpegtran    $(INSTALL_PROGRAM) rdjpgcom $(bindir)/$(binprefix)rdjpgcom    $(INSTALL_PROGRAM) wrjpgcom $(bindir)/$(binprefix)wrjpgcominstall-lib: libjpeg.$(A) install-headers    $(INSTALL_LIB) libjpeg.$(A) $(libdir)/$(binprefix)libjpeg.$(A)install-headers: jconfig.h    $(INSTALL_DATA) jconfig.h $(includedir)/jconfig.h    $(INSTALL_DATA) $(srcdir)/jpeglib.h $(includedir)/jpeglib.h    $(INSTALL_DATA) $(srcdir)/jmorecfg.h $(includedir)/jmorecfg.h    $(INSTALL_DATA) $(srcdir)/jerror.h $(includedir)/jerror.hclean:    $(RM) *.o *.lo libjpeg.a libjpeg.la    $(RM) cjpeg djpeg jpegtran rdjpgcom wrjpgcom    $(RM) ansi2knr core testout* config.log config.status    $(RM) -r knr .libs _libsdistclean: clean    $(RM) Makefile jconfig.h libtool config.cachetest: cjpeg djpeg jpegtran    $(RM) testout*    ./djpeg -dct int -ppm -outfile testout.ppm  $(srcdir)/testorig.jpg    ./djpeg -dct int -bmp -colors 256 -outfile testout.bmp  $(srcdir)/testorig.jpg    ./cjpeg -dct int -outfile testout.jpg  $(srcdir)/testimg.ppm    ./djpeg -dct int -ppm -outfile testoutp.ppm $(srcdir)/testprog.jpg    ./cjpeg -dct int -progressive -opt -outfile testoutp.jpg $(srcdir)/testimg.ppm    ./jpegtran -outfile testoutt.jpg $(srcdir)/testprog.jpg    cmp $(srcdir)/testimg.ppm testout.ppm    cmp $(srcdir)/testimg.bmp testout.bmp    cmp $(srcdir)/testimg.jpg testout.jpg    cmp $(srcdir)/testimg.ppm testoutp.ppm    cmp $(srcdir)/testimgp.jpg testoutp.jpg    cmp $(srcdir)/testorig.jpg testoutt.jpgcheck: test# Mistake catcher:jconfig.h: jconfig.doc    echo You must prepare a system-dependent jconfig.h file.    echo Please read the installation directions in install.doc.    exit 1# GNU Make likes to know which target names are not really files to be made:.PHONY: all install install-lib install-headers clean distclean test checkjcapimin.$(O): jcapimin.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcapistd.$(O): jcapistd.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjccoefct.$(O): jccoefct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjccolor.$(O): jccolor.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcdctmgr.$(O): jcdctmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjchuff.$(O): jchuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jchuff.hjcinit.$(O): jcinit.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcmainct.$(O): jcmainct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcmarker.$(O): jcmarker.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcmaster.$(O): jcmaster.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcomapi.$(O): jcomapi.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcparam.$(O): jcparam.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcphuff.$(O): jcphuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jchuff.hjcprepct.$(O): jcprepct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcsample.$(O): jcsample.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjctrans.$(O): jctrans.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdapimin.$(O): jdapimin.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdapistd.$(O): jdapistd.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdatadst.$(O): jdatadst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.hjdatasrc.$(O): jdatasrc.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.hjdcoefct.$(O): jdcoefct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdcolor.$(O): jdcolor.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjddctmgr.$(O): jddctmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjdhuff.$(O): jdhuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdhuff.hjdinput.$(O): jdinput.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmainct.$(O): jdmainct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmarker.$(O): jdmarker.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmaster.$(O): jdmaster.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmerge.$(O): jdmerge.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdphuff.$(O): jdphuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdhuff.hjdpostct.$(O): jdpostct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdsample.$(O): jdsample.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdtrans.$(O): jdtrans.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjerror.$(O): jerror.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jversion.h jerror.hjfdctflt.$(O): jfdctflt.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjfdctfst.$(O): jfdctfst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjfdctint.$(O): jfdctint.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctflt.$(O): jidctflt.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctfst.$(O): jidctfst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctint.$(O): jidctint.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctred.$(O): jidctred.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjquant1.$(O): jquant1.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjquant2.$(O): jquant2.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjutils.$(O): jutils.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjmemmgr.$(O): jmemmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemansi.$(O): jmemansi.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemname.$(O): jmemname.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemnobs.$(O): jmemnobs.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemdos.$(O): jmemdos.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemmac.$(O): jmemmac.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hcjpeg.$(O): cjpeg.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h jversion.hdjpeg.$(O): djpeg.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h jversion.hjpegtran.$(O): jpegtran.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h transupp.h jversion.hrdjpgcom.$(O): rdjpgcom.c jinclude.h jconfig.hwrjpgcom.$(O): wrjpgcom.c jinclude.h jconfig.hcdjpeg.$(O): cdjpeg.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdcolmap.$(O): rdcolmap.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdswitch.$(O): rdswitch.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.htransupp.$(O): transupp.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h transupp.hrdppm.$(O): rdppm.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrppm.$(O): wrppm.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdgif.$(O): rdgif.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrgif.$(O): wrgif.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdtarga.$(O): rdtarga.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrtarga.$(O): wrtarga.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdbmp.$(O): rdbmp.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrbmp.$(O): wrbmp.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdrle.$(O): rdrle.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrrle.$(O): wrrle.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h

执行命令之后：

# Generated automatically from makefile.cfg by configure.# Makefile for Independent JPEG Group's software# makefile.cfg is edited by configure to produce a custom Makefile.# Read installation instructions before saying "make" !!# For compiling with source and object files in different directories.srcdir = .# Where to install the programs and man pages.prefix = /home/davinci/jpeg_arm/exec_prefix = /home/davinci/jpeg_arm/bindir = $(exec_prefix)/binlibdir = $(exec_prefix)/libincludedir = $(prefix)/includebinprefix =manprefix =manext = 1mandir = $(prefix)/man/man$(manext)# The name of your C compiler:CC= /opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi-gcc# You may need to adjust these cc options:CFLAGS= -O2  -I$(srcdir)# Generally, we recommend defining any configuration symbols in jconfig.h,# NOT via -D switches here.# However, any special defines for ansi2knr.c may be included here:ANSI2KNRFLAGS= # Link-time cc options:LDFLAGS= # To link any special libraries, add the necessary -l commands here.LDLIBS= # If using GNU libtool, LIBTOOL references it; if not, LIBTOOL is empty.LIBTOOL = ./libtool# $(O) expands to "lo" if using libtool, plain "o" if not.# Similarly, $(A) expands to "la" or "a".O = loA = la# Library version ID; libtool uses this for the shared library version number.# Note: we suggest this match the macro of the same name in jpeglib.h.JPEG_LIB_VERSION = 62# Put here the object file name for the correct system-dependent memory# manager file.  For Unix this is usually jmemnobs.o, but you may want# to use jmemansi.o or jmemname.o if you have limited swap space.SYSDEPMEM= jmemnobs.$(O)# miscellaneous OS-dependent stuffSHELL= /bin/sh# linkerLN= $(LIBTOOL) --mode=link $(CC)# file deletion commandRM= rm -f# directory creation commandMKDIR= mkdir# library (.a) file creation commandAR= /opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi-ar rc# second step in .a creation (use "touch" if not needed)AR2= /opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi-ranlib# installation programINSTALL= /usr/bin/install -cINSTALL_PROGRAM= $(LIBTOOL) --mode=install ${INSTALL}INSTALL_LIB= $(LIBTOOL) --mode=install ${INSTALL}INSTALL_DATA= ${INSTALL} -m 644# End of configurable options.# source files: JPEG library properLIBSOURCES= jcapimin.c jcapistd.c jccoefct.c jccolor.c jcdctmgr.c jchuff.c \        jcinit.c jcmainct.c jcmarker.c jcmaster.c jcomapi.c jcparam.c \        jcphuff.c jcprepct.c jcsample.c jctrans.c jdapimin.c jdapistd.c \        jdatadst.c jdatasrc.c jdcoefct.c jdcolor.c jddctmgr.c jdhuff.c \        jdinput.c jdmainct.c jdmarker.c jdmaster.c jdmerge.c jdphuff.c \        jdpostct.c jdsample.c jdtrans.c jerror.c jfdctflt.c jfdctfst.c \        jfdctint.c jidctflt.c jidctfst.c jidctint.c jidctred.c jquant1.c \        jquant2.c jutils.c jmemmgr.c# memmgr back ends: compile only one of these into a working librarySYSDEPSOURCES= jmemansi.c jmemname.c jmemnobs.c jmemdos.c jmemmac.c# source files: cjpeg/djpeg/jpegtran applications, also rdjpgcom/wrjpgcomAPPSOURCES= cjpeg.c djpeg.c jpegtran.c rdjpgcom.c wrjpgcom.c cdjpeg.c \        rdcolmap.c rdswitch.c transupp.c rdppm.c wrppm.c rdgif.c wrgif.c \        rdtarga.c wrtarga.c rdbmp.c wrbmp.c rdrle.c wrrle.cSOURCES= $(LIBSOURCES) $(SYSDEPSOURCES) $(APPSOURCES)# files included by source filesINCLUDES= jchuff.h jdhuff.h jdct.h jerror.h jinclude.h jmemsys.h jmorecfg.h \        jpegint.h jpeglib.h jversion.h cdjpeg.h cderror.h transupp.h# documentation, test, and support filesDOCS= README install.doc usage.doc cjpeg.1 djpeg.1 jpegtran.1 rdjpgcom.1 \        wrjpgcom.1 wizard.doc example.c libjpeg.doc structure.doc \        coderules.doc filelist.doc change.logMKFILES= configure makefile.cfg makefile.ansi makefile.unix makefile.bcc \        makefile.mc6 makefile.dj makefile.wat makefile.vc makelib.ds \        makeapps.ds makeproj.mac makcjpeg.st makdjpeg.st makljpeg.st \        maktjpeg.st makefile.manx makefile.sas makefile.mms makefile.vms \        makvms.optCONFIGFILES= jconfig.cfg jconfig.bcc jconfig.mc6 jconfig.dj jconfig.wat \        jconfig.vc jconfig.mac jconfig.st jconfig.manx jconfig.sas \        jconfig.vmsCONFIGUREFILES= config.guess config.sub install-sh ltconfig ltmain.shOTHERFILES= jconfig.doc ckconfig.c ansi2knr.c ansi2knr.1 jmemdosa.asmTESTFILES= testorig.jpg testimg.ppm testimg.bmp testimg.jpg testprog.jpg \        testimgp.jpgDISTFILES= $(DOCS) $(MKFILES) $(CONFIGFILES) $(SOURCES) $(INCLUDES) \        $(CONFIGUREFILES) $(OTHERFILES) $(TESTFILES)# library object files common to compression and decompressionCOMOBJECTS= jcomapi.$(O) jutils.$(O) jerror.$(O) jmemmgr.$(O) $(SYSDEPMEM)# compression library object filesCLIBOBJECTS= jcapimin.$(O) jcapistd.$(O) jctrans.$(O) jcparam.$(O) \        jdatadst.$(O) jcinit.$(O) jcmaster.$(O) jcmarker.$(O) jcmainct.$(O) \        jcprepct.$(O) jccoefct.$(O) jccolor.$(O) jcsample.$(O) jchuff.$(O) \        jcphuff.$(O) jcdctmgr.$(O) jfdctfst.$(O) jfdctflt.$(O) \        jfdctint.$(O)# decompression library object filesDLIBOBJECTS= jdapimin.$(O) jdapistd.$(O) jdtrans.$(O) jdatasrc.$(O) \        jdmaster.$(O) jdinput.$(O) jdmarker.$(O) jdhuff.$(O) jdphuff.$(O) \        jdmainct.$(O) jdcoefct.$(O) jdpostct.$(O) jddctmgr.$(O) \        jidctfst.$(O) jidctflt.$(O) jidctint.$(O) jidctred.$(O) \        jdsample.$(O) jdcolor.$(O) jquant1.$(O) jquant2.$(O) jdmerge.$(O)# These objectfiles are included in libjpeg.aLIBOBJECTS= $(CLIBOBJECTS) $(DLIBOBJECTS) $(COMOBJECTS)# object files for sample applications (excluding library files)COBJECTS= cjpeg.$(O) rdppm.$(O) rdgif.$(O) rdtarga.$(O) rdrle.$(O) \        rdbmp.$(O) rdswitch.$(O) cdjpeg.$(O)DOBJECTS= djpeg.$(O) wrppm.$(O) wrgif.$(O) wrtarga.$(O) wrrle.$(O) \        wrbmp.$(O) rdcolmap.$(O) cdjpeg.$(O)TROBJECTS= jpegtran.$(O) rdswitch.$(O) cdjpeg.$(O) transupp.$(O)all:  libjpeg.$(A) cjpeg djpeg jpegtran rdjpgcom wrjpgcom# Special compilation rules to support ansi2knr and libtool..SUFFIXES: .lo .la# How to compile with libtool..c.lo:    $(LIBTOOL) --mode=compile $(CC) $(CFLAGS) -c $(srcdir)/$*.c# How to use ansi2knr, when not using libtool.# .c.o:#   ./ansi2knr $(srcdir)/$*.c knr/$*.c#   $(CC) $(CFLAGS) -c knr/$*.c#   $(RM) knr/$*.c# How to use ansi2knr AND libtool.# .c.lo:#   ./ansi2knr $(srcdir)/$*.c knr/$*.c#   $(LIBTOOL) --mode=compile $(CC) $(CFLAGS) -c knr/$*.c#   $(RM) knr/$*.cansi2knr: ansi2knr.c    $(CC) $(CFLAGS) $(ANSI2KNRFLAGS) -o ansi2knr $(srcdir)/ansi2knr.c    $(MKDIR) knr# the library:# without libtool:libjpeg.a:  $(LIBOBJECTS)    $(RM) libjpeg.a    $(AR) libjpeg.a  $(LIBOBJECTS)    $(AR2) libjpeg.a# with libtool:libjpeg.la:  $(LIBOBJECTS)    $(LIBTOOL) --mode=link $(CC) -o libjpeg.la $(LIBOBJECTS) \        -rpath $(libdir) -version-info $(JPEG_LIB_VERSION)# sample programs:cjpeg: $(COBJECTS) libjpeg.$(A)    $(LN) $(LDFLAGS) -o cjpeg $(COBJECTS) libjpeg.$(A) $(LDLIBS)djpeg: $(DOBJECTS) libjpeg.$(A)    $(LN) $(LDFLAGS) -o djpeg $(DOBJECTS) libjpeg.$(A) $(LDLIBS)jpegtran: $(TROBJECTS) libjpeg.$(A)    $(LN) $(LDFLAGS) -o jpegtran $(TROBJECTS) libjpeg.$(A) $(LDLIBS)rdjpgcom: rdjpgcom.$(O)    $(LN) $(LDFLAGS) -o rdjpgcom rdjpgcom.$(O) $(LDLIBS)wrjpgcom: wrjpgcom.$(O)    $(LN) $(LDFLAGS) -o wrjpgcom wrjpgcom.$(O) $(LDLIBS)# Installation rules:install: cjpeg djpeg jpegtran rdjpgcom wrjpgcom install-lib    $(INSTALL_PROGRAM) cjpeg $(bindir)/$(binprefix)cjpeg    $(INSTALL_PROGRAM) djpeg $(bindir)/$(binprefix)djpeg    $(INSTALL_PROGRAM) jpegtran $(bindir)/$(binprefix)jpegtran    $(INSTALL_PROGRAM) rdjpgcom $(bindir)/$(binprefix)rdjpgcom    $(INSTALL_PROGRAM) wrjpgcom $(bindir)/$(binprefix)wrjpgcominstall-lib: libjpeg.$(A) install-headers    $(INSTALL_LIB) libjpeg.$(A) $(libdir)/$(binprefix)libjpeg.$(A)install-headers: jconfig.h    $(INSTALL_DATA) jconfig.h $(includedir)/jconfig.h    $(INSTALL_DATA) $(srcdir)/jpeglib.h $(includedir)/jpeglib.h    $(INSTALL_DATA) $(srcdir)/jmorecfg.h $(includedir)/jmorecfg.h    $(INSTALL_DATA) $(srcdir)/jerror.h $(includedir)/jerror.hclean:    $(RM) *.o *.lo libjpeg.a libjpeg.la    $(RM) cjpeg djpeg jpegtran rdjpgcom wrjpgcom    $(RM) ansi2knr core testout* config.log config.status    $(RM) -r knr .libs _libsdistclean: clean    $(RM) Makefile jconfig.h libtool config.cachetest: cjpeg djpeg jpegtran    $(RM) testout*    ./djpeg -dct int -ppm -outfile testout.ppm  $(srcdir)/testorig.jpg    ./djpeg -dct int -bmp -colors 256 -outfile testout.bmp  $(srcdir)/testorig.jpg    ./cjpeg -dct int -outfile testout.jpg  $(srcdir)/testimg.ppm    ./djpeg -dct int -ppm -outfile testoutp.ppm $(srcdir)/testprog.jpg    ./cjpeg -dct int -progressive -opt -outfile testoutp.jpg $(srcdir)/testimg.ppm    ./jpegtran -outfile testoutt.jpg $(srcdir)/testprog.jpg    cmp $(srcdir)/testimg.ppm testout.ppm    cmp $(srcdir)/testimg.bmp testout.bmp    cmp $(srcdir)/testimg.jpg testout.jpg    cmp $(srcdir)/testimg.ppm testoutp.ppm    cmp $(srcdir)/testimgp.jpg testoutp.jpg    cmp $(srcdir)/testorig.jpg testoutt.jpgcheck: test# Mistake catcher:jconfig.h: jconfig.doc    echo You must prepare a system-dependent jconfig.h file.    echo Please read the installation directions in install.doc.    exit 1# GNU Make likes to know which target names are not really files to be made:.PHONY: all install install-lib install-headers clean distclean test checkjcapimin.$(O): jcapimin.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcapistd.$(O): jcapistd.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjccoefct.$(O): jccoefct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjccolor.$(O): jccolor.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcdctmgr.$(O): jcdctmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjchuff.$(O): jchuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jchuff.hjcinit.$(O): jcinit.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcmainct.$(O): jcmainct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcmarker.$(O): jcmarker.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcmaster.$(O): jcmaster.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcomapi.$(O): jcomapi.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcparam.$(O): jcparam.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcphuff.$(O): jcphuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jchuff.hjcprepct.$(O): jcprepct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjcsample.$(O): jcsample.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjctrans.$(O): jctrans.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdapimin.$(O): jdapimin.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdapistd.$(O): jdapistd.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdatadst.$(O): jdatadst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.hjdatasrc.$(O): jdatasrc.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.hjdcoefct.$(O): jdcoefct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdcolor.$(O): jdcolor.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjddctmgr.$(O): jddctmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjdhuff.$(O): jdhuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdhuff.hjdinput.$(O): jdinput.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmainct.$(O): jdmainct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmarker.$(O): jdmarker.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmaster.$(O): jdmaster.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdmerge.$(O): jdmerge.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdphuff.$(O): jdphuff.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdhuff.hjdpostct.$(O): jdpostct.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdsample.$(O): jdsample.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjdtrans.$(O): jdtrans.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjerror.$(O): jerror.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jversion.h jerror.hjfdctflt.$(O): jfdctflt.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjfdctfst.$(O): jfdctfst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjfdctint.$(O): jfdctint.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctflt.$(O): jidctflt.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctfst.$(O): jidctfst.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctint.$(O): jidctint.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjidctred.$(O): jidctred.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jdct.hjquant1.$(O): jquant1.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjquant2.$(O): jquant2.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjutils.$(O): jutils.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.hjmemmgr.$(O): jmemmgr.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemansi.$(O): jmemansi.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemname.$(O): jmemname.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemnobs.$(O): jmemnobs.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemdos.$(O): jmemdos.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hjmemmac.$(O): jmemmac.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h jmemsys.hcjpeg.$(O): cjpeg.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h jversion.hdjpeg.$(O): djpeg.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h jversion.hjpegtran.$(O): jpegtran.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h transupp.h jversion.hrdjpgcom.$(O): rdjpgcom.c jinclude.h jconfig.hwrjpgcom.$(O): wrjpgcom.c jinclude.h jconfig.hcdjpeg.$(O): cdjpeg.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdcolmap.$(O): rdcolmap.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdswitch.$(O): rdswitch.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.htransupp.$(O): transupp.c jinclude.h jconfig.h jpeglib.h jmorecfg.h jpegint.h jerror.h transupp.hrdppm.$(O): rdppm.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrppm.$(O): wrppm.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdgif.$(O): rdgif.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrgif.$(O): wrgif.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdtarga.$(O): rdtarga.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrtarga.$(O): wrtarga.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdbmp.$(O): rdbmp.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrbmp.$(O): wrbmp.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hrdrle.$(O): rdrle.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.hwrrle.$(O): wrrle.c cdjpeg.h jinclude.h jconfig.h jpeglib.h jmorecfg.h jerror.h cderror.h

好好对比一下两个Makefile内容。我们会发现，编译器和安装目录设置。

step3、创建make以后安装lib和include，以及bin的文件目录

sudo mkdir /home/davinci/jpeg_armsudo mkdir /home/davinci/jpeg_arm/libsudo mkdir /home/davinci/jpeg_arm/include

step4、编译

sudo make

step5、安装

sudo make install

注意：step3必须做，否则make install安装的时候，一定会报文件找不到的错误。

第二 步：基于libjpeg完成jpg和bmp的C语言程序

首先，去看看jpeg-6b/下面的example.c文件，主要是可以了解一下libjpeg的基本用法。

注意：#include “include/jpeglib.h”这句话，我为什么这么写？是因为我的这个源码文件就在/home/davinci/jpeg_arm/目录下，其实就是执行sudo make install的安装目录。

然后，我先摆上jpg2bmp.c的源码：

#include <stdio.h>#include <setjmp.h>#include <string.h>#include <stdlib.h>#include "include/jpeglib.h"//value low 8bit write to array[offset]//value high 8bit write to array[offset +1]#define put_2b(array,offset,value) array[offset] = (char) ((value) & 0xff);\                array[offset+1] = (char) (((value) >> 8) & 0xff)#define put_4b(array,offset,value)   \        (array[offset] = (char) ((value) & 0xff),\        array[offset+1] = (char) (((value) >> 8) & 0xff),\        array[offset+2] = (char) (((value) >> 16) & 0xff),\        array[offset+3] = (char) (((value) >> 24) & 0xff))//write head file void write_bmp_header(j_decompress_ptr cinfo, FILE *output_file){    char bmpfileheader[14];    char bmpinfoheader[40];    long headersize, bfsize;    int bits_per_pixel, cmap_entries;    struct colormap{  //the struct of color table    UINT8 blue;    UINT8 green;    UINT8 red;    UINT8 reserved;    };    int step;    int i=0;    /* compute colormap size and total file size */    if (cinfo->out_color_space == JCS_RGB) {        if (cinfo->quantize_colors) {            /* colormapped rgb */            bits_per_pixel = 8;            cmap_entries = 256;        } else {            /* unquantized, full color rgb */            bits_per_pixel = 24;            cmap_entries = 0;        }    } else {    /* grayscale output.  we need to fake a 256-entry colormap. */        bits_per_pixel = 8;        cmap_entries = 256;    }    step = cinfo->output_width * cinfo->output_components;    while ((step & 3) != 0) step++;    /* file size */    headersize = 14 + 40 + cmap_entries * 4; /* header and colormap */    bfsize = headersize + (long) step * (long) cinfo->output_height;    /* set unused fields of header to 0 */    memset(bmpfileheader, 0, sizeof(bmpfileheader));    memset(bmpinfoheader, 0 ,sizeof(bmpinfoheader));    /* fill the file header */    bmpfileheader[0] = 0x42;/* first 2 bytes are ascii 'b', 'm' */    bmpfileheader[1] = 0x4d;    put_4b(bmpfileheader, 2, bfsize); /* bfsize */    /* we leave bfreserved1 & bfreserved2 = 0 */    put_4b(bmpfileheader, 10, headersize); /* bfoffbits */    /* fill the info header (microsoft calls this a bitmapinfoheader) */    put_2b(bmpinfoheader, 0, 40);   /* bisize */    put_4b(bmpinfoheader, 4, cinfo->output_width); /* biwidth */    put_4b(bmpinfoheader, 8, cinfo->output_height); /* biheight */    put_2b(bmpinfoheader, 12, 1);   /* biplanes - must be 1 */    put_2b(bmpinfoheader, 14, bits_per_pixel); /* bibitcount */    /* we leave bicompression = 0, for none */    /* we leave bisizeimage = 0; this is correct for uncompressed data */    if (cinfo->density_unit == 2) { /* if have density in dots/cm, then */        put_4b(bmpinfoheader, 24, (INT32) (cinfo->X_density*100)); /* xpels/m */        put_4b(bmpinfoheader, 28, (INT32) (cinfo->Y_density*100)); /* xpels/m */    }    put_2b(bmpinfoheader, 32, cmap_entries); /* biclrused */    /* we leave biclrimportant = 0 */    //write file head    if (fwrite(bmpfileheader, 1, 14, output_file) != (size_t) 14) {        printf("write bmpfileheader error\n");    }       //write info head    if (fwrite(bmpinfoheader, 1, 40, output_file) != (size_t) 40) {        printf("write bmpinfoheader error\n");    }    //write color table or gray table    if (cmap_entries ==256) {        struct colormap rgb[256];        for(i=0;i<256;i++)        {                rgb[i].blue=i;            rgb[i].green=i;            rgb[i].red=i;            rgb[i].reserved=0;        }        //write color table        if (fwrite(rgb, 1, sizeof(struct colormap)*256, output_file) <0) {            printf("write color error\n");        }    }}//write bitmap data void write_pixel_data(j_decompress_ptr cinfo, unsigned char *output_buffer, FILE *output_file){    int rows, cols;    int row_width;    int step;    unsigned char *tmp = NULL;    unsigned char *pdata;    row_width = cinfo->output_width * cinfo->output_components;    step = row_width;    while ((step & 3) != 0) step++;    pdata = (unsigned char *)malloc(step);    memset(pdata, 0, step);    //we need to change the order while change line    //bgr in the window, but rgb in the libjpeg    tmp = output_buffer + row_width * (cinfo->output_height - 1);    if(cinfo->output_components==3){ //24bit real color piture        for (rows = 0; rows < cinfo->output_height; rows++) {            for (cols = 0; cols < row_width; cols += 3) {                pdata[cols + 2] = tmp[cols + 0];                pdata[cols + 1] = tmp[cols + 1];                pdata[cols + 0] = tmp[cols + 2];            }            tmp -= row_width;            fwrite(pdata, 1, step, output_file);        }    }    else //cinfo->output_components==1，8bit gray picture    {        for (rows = 0; rows < cinfo->output_height; rows++) {            for (cols = 0; cols < row_width; cols ++) {                pdata[cols] = tmp[cols];            }            tmp -= row_width;            fwrite(pdata, 1, step, output_file);        }    }    free(pdata);}//refer to example.c int read_jpeg_file(const char *input_filename, const char *output_filename){    struct jpeg_decompress_struct cinfo;    struct jpeg_error_mgr jerr;    FILE *input_file;    FILE *output_file;    JSAMPARRAY buffer;    int row_width;    unsigned char *output_buffer;    unsigned char *tmp = NULL;    cinfo.err = jpeg_std_error(&jerr);    if ((input_file = fopen(input_filename, "rb")) == NULL) {        fprintf(stderr, "can't open %s\n", input_filename);        return -1;    }    if ((output_file = fopen(output_filename, "wb")) == NULL) {        fprintf(stderr, "can't open %s\n", output_filename);        return -1;    }    jpeg_create_decompress(&cinfo);    /* specify data source for decompression */    jpeg_stdio_src(&cinfo, input_file);    /* read file header, set default decompression parameters */    (void) jpeg_read_header(&cinfo, TRUE);    /* start decompressor */    (void) jpeg_start_decompress(&cinfo);    row_width = cinfo.output_width * cinfo.output_components;    buffer = (*cinfo.mem->alloc_sarray)            ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_width, 1);    //write bmp file head    write_bmp_header(&cinfo, output_file);    //alloc bmp buffer     output_buffer = (unsigned char *)malloc(row_width * cinfo.output_height);    memset(output_buffer, 0, row_width * cinfo.output_height);    tmp = output_buffer;    /* process data */    while (cinfo.output_scanline < cinfo.output_height) {    (void) jpeg_read_scanlines(&cinfo, buffer, 1);    memcpy(tmp, *buffer, row_width);    tmp += row_width;    }    //write bmp data    write_pixel_data(&cinfo, output_buffer, output_file);    free(output_buffer);    (void) jpeg_finish_decompress(&cinfo);    jpeg_destroy_decompress(&cinfo);    /* close files, if we opened them */    fclose(input_file);    fclose(output_file);    return 0;}int main(int argc, char *argv[]){    if (argc < 3) {        //read_jpeg_file("tt.jpg", "tt.bmp");        printf("use:appname inputfile outputfile!\n");    } else {        read_jpeg_file(argv[1], argv[2]);    }    return 0;}

接着就是完成源码文件的编译：以我自己的为例子，

/opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi-gcc -L /home/davinci/jpeg_arm/lib -o jpg2bmp jpg2bmp.c -ljpeg

执行成功以后，将jpg2bmp二进制文件移动到dm368的板上linux系统。使用:

./jpg2bmp test.jpg test.bmp

执行成功以后，就会在同目录下面生成一个test.bmp文件。
使用：

du -sh test.bmp 

查看一下文件大小，我们会发现文件大小大概会从76k变成2.6M。

最后，摆上bmp2jpg.c源码文件：

同样要注意，#include “include/jpeglib.h”，依然是同目录的。

#include <stdio.h>#include <setjmp.h>#include <string.h>#include <stdlib.h>#include "include/jpeglib.h"FILE *bmpfile;//input fileint image_width,image_height,image_size,bits_per_pixel,headersize,depth;unsigned char *src_data;//bitmap data int get_2b(unsigned char*a,int offset){    return a[offset+1]<<8|a[offset];}int get_4b(unsigned char*a,int offset){    return (a[offset+3]<<24)|(a[offset+2]<<16)|(a[offset+1]<<8)|a[offset];}//read bitmap head and datavoid read_bmp_header(char *bmpfilename){    unsigned char bmpfileheader[14];//file head    unsigned char bmpinfoheader[40];//info head    bmpfile=fopen(bmpfilename,"r");//    if(bmpfile<0)        printf("open bmp file error!\n");    printf("open bmp file success!\n");    //read the bmp file head    fread(bmpfileheader,14,1,bmpfile);    int type=get_2b(bmpfileheader,0);    printf("type=0x%x\n",type);    int filesize=get_4b(bmpfileheader,2);    printf("filesize=%d bytes\n",filesize);    headersize=get_4b(bmpfileheader,10);    printf("headersize=%d bytes\n",headersize);    if(headersize>54)        printf("colormap size=%d bytes\n",headersize-54);    //read the bmp info head    fseek(bmpfile,14,SEEK_SET);    fread(bmpinfoheader,40,1,bmpfile);    image_width=get_4b(bmpinfoheader,4);    /*the width must be %4 ==0, otherwise the picture is unnormal */    while (image_width%4!=0)        image_width++;    printf("weight=%d\n",image_width);    image_height=get_4b(bmpinfoheader,8);    printf("height=%d\n",image_height);    bits_per_pixel=get_2b(bmpinfoheader,14);    printf("bits_per_pixel=%d\n",bits_per_pixel);    depth=bits_per_pixel/8;    image_size=image_width*image_height*depth;    src_data=(unsigned char *)malloc(image_size);    fseek(bmpfile,headersize,SEEK_SET);    fread(src_data,sizeof(unsigned char)*image_size,1,bmpfile);    fclose(bmpfile);}//refer to example.cvoid write_jpeg_file (char * outfilename, unsigned char * buffer,int quality){    struct jpeg_compress_struct cinfo;    struct jpeg_error_mgr jerr;    FILE * outfile;    unsigned char *dst_data;    int i,j;    //char *point;    JSAMPROW row_pointer[1];    //js amparray buffer;    int row_stride;    cinfo.err = jpeg_std_error(&jerr);    jpeg_create_compress(&cinfo);    //open output jpg file     if ((outfile = fopen(outfilename, "w+")) == NULL) {        fprintf(stderr, "can't open %s\n", outfilename);        exit(1);    }    jpeg_stdio_dest(&cinfo, outfile);    cinfo.image_width = image_width;     /* image width and height, in pixels */    cinfo.image_height = image_height;    cinfo.input_components = depth;        /* # of color components per pixel */    cinfo.in_color_space = (depth==3) ? JCS_RGB : JCS_GRAYSCALE;     /* colorspace of input image */    jpeg_set_defaults(&cinfo);    jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-jpeg values */);    dst_data=(unsigned char *)malloc(image_size*sizeof(unsigned char));    //modify the order rgb: bgr->rgb    for(i=0;i<image_height;i++){        for(j=0;j<image_width;j++)        {            if(depth==1)//gray picture                *(dst_data+i*image_width+j)=*(src_data+i*image_width+j);            else //real color picture            {                *(dst_data+i*image_width*depth+j*3+0)=*(src_data+i*image_width*depth+j*3+2);                *(dst_data+i*image_width*depth+j*3+1)=*(src_data+i*image_width*depth+j*3+1);                *(dst_data+i*image_width*depth+j*3+2)=*(src_data+i*image_width*depth+j*3+0);            }        }    }    jpeg_start_compress(&cinfo, TRUE);    row_stride = image_width * cinfo.input_components;    /* js amples per row in image_buffer */    while (cinfo.next_scanline < cinfo.image_height) {        row_pointer[0] = & dst_data[(cinfo.image_height - cinfo.next_scanline - 1) * row_stride];//cinfo.next_scanline * row_stride            (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);    }    jpeg_finish_compress(&cinfo);    fclose(outfile);    jpeg_destroy_compress(&cinfo);    free(src_data);    free(dst_data);}int main(int argc,char *argv[]){    if(argc<4)        printf("use:appname inputname outputname quality\n");    else    {        read_bmp_header(argv[1]);        write_jpeg_file(argv[2],src_data,atoi(argv[3]));    }    return 0;}

使用如下命令完成编译：

/opt/codesourcery/arm-2009q1/bin/arm-none-linux-gnueabi-gcc -L /home/davinci/jpeg_arm/lib -o bmp2jpg.c bmp2jpg.c -ljpeg

还是像jpg2bmp一样，移动到dm368的板上linux系统。使用：

./bmp2jpg test.bmp test.jpg 75

解释一下，75，代表bmp转成jpg的压缩图像质量，有效值是5-95之间。值越大，压缩后的jpg图片质量越好，但是文件尺寸也越大。

最后，解释一下编译的

“-L /home/davinci/jpeg_arm/lib”指定编译的库目录

“-ljpeg”是怎么得来的？去看看/home/davinci/jpeg_arm/lib目录下面有什么文件，我们确实是指定了库的目录，但是并不是所有的库我们都需要的，所以我们要确切的指定。那么指定的规则是什么？首先，在lib目录下有这么几个文件：libjpeg.la、libjpeg.so、libjpeg.so.62、libjpeg.so.62.0.0一共4个文件。去掉前缀lib和后缀就只剩下jpeg，然而具体指定需要使用-l（小写L），最后综合一下就是 -ljpeg

到现在为止，libjpeg移植和应用完成。

最后，在说一句。基本上所有的linux嵌入式移植都是这个流程。