JPEG Lib的交叉編譯

step1:下載並解壓jpeg源代碼包

step2:
 #cd ./jpeg-6b
 #./configure --prefix=/home/jpeg_arm_include --exec-prefix=/home/jpeg_arm_lib /
               --enable-shared --enable-static
 下面分別介紹這幾個參數的作用:
 
 --prefix=/home/jpeg_arm_include : 執行make install 後,會將與體系無關的文件拷貝到此目錄下,具體如下:
 /home/jpeg_arm_include.....................................
        |
       +---include........................................
             |
             ---jconfig.h
             |
             ---jerror.h
             |
             ---jmorecfg.h
             |
             ---jpeglib.h
       +---man............................................
             |
            +---man1.......................................
                  |
                  ---cjeg.1
                  |
                  ---djpeg.1
                  |
                  ---jpegtran.1
                  |
                  ---rdjpgcom.1
                  |
                  ---wrjpgcom.1
               
 --exec-prefix=/home/jpeg_arm_lib : 執行make install 後,會將與體系無關的文件拷貝到此目錄下,即將一些可執行程序、動態鏈接庫和靜態鏈接庫拷貝到此目錄的相應目錄下，具體如下：
 /home/jpeg_arm_lib........................................
        |
       +---bin............................................
             |
             ---cjeg
             |
             ---djpeg
             |
             ---jpegtran
             |
             ---rdjpgcom
             |
             ---wrjpgcom
       +---lib...........................................
             |
             ---libjpeg.la
             |
             ---libjpeg.so 
             |
             ---libjpeg.so.62
             |
             ---libjpeg.so.62.0.0 
           
 --enable-shared : 用GNU libtool編譯成動態鏈接庫 。下面分別對應有無此參數所生成的Makefile的比較:
       ------------------------------------------------------------------------------------------- 
              無--enable-shared參數             |               有--enable-shared參數
       ------------------------------------------------------------------------------------------- 
                          LIBTOOL =                   |            LIBTOOL = ./libtool
       -------------------------------------------------------------------------------------------
                           O = o  A = a                 |            O = lo    A = la
       -------------------------------------------------------------------------------------------
                          LN= $(CC)                    |      LN= $(LIBTOOL) --mode=link $(CC)
       -------------------------------------------------------------------------------------------
    INSTALL_PROGRAM= ${INSTALL}     |  INSTALL_PROGRAM= $(LIBTOOL) --mode=install ${INSTALL}
        INSTALL_LIB= ${INSTALL} -m 644  |  INSTALL_LIB= $(LIBTOOL) --mode=install ${INSTALL}
      -------------------------------------------------------------------------------------------------------
           無參數:
              # .c.lo:
              #  $(LIBTOOL) --mode=compile $(CC) $(CFLAGS) -c $(srcdir)/$*.c
           有參數:
              .c.lo:
              $(LIBTOOL) --mode=compile $(CC) $(CFLAGS) -c $(srcdir)/$*.c
   ----------------------------------------------------------------------------------------------------------
          無參數:
             install: cjpeg djpeg jpegtran rdjpgcom wrjpgcom
          有參數: 
             install: cjpeg djpeg jpegtran rdjpgcom wrjpgcom install-lib
    -----------------------------------------------------------------------------------------------------------

step3:修改生成的Makefile文件:
       # The name of your C compiler:
       CC= gcc  該成  CC=/usr/local/arm-linux/bin/arm-linux-gcc (根據你自己交叉編譯器的位置修改)
       # library (.a) file creation command
       AR= ar rc 該成  AR= /usr/local/arm-linux/arm-linux/bin/ar rc  (同上)
       # second step in .a creation (use "touch" if not needed)
       AR2= ranlib 該成  AR2= /usr/local/arm-linux/arm-linux/bin/ranlib (同上)

step4:#make
      #make install
      這樣JPEG庫就交叉編譯成功了,相應的庫和頭文件都在/home/jpeg_arm_lib和/home/jpeg_arm_include下了!