一:生成动态库(.so文件)
-->环境:
操作系统:Ubuntu9.10
ffmpeg源码版本:ffmpeg-0.6.1(可以在http://ffmpeg.org/download.html 下载源码)
androidndk版本:android-ndk-r4b-linux-x86(可以在http://androidappdocs.appspot.com/sdk/ndk/index.html 下载)
-->设置NDK环境变量:
1、用root用户登陆,打开命令窗口,输入cd/root
2、输入ls-a,会显示一个隐藏文件.bashrc
3、输入vi.bashrc,按i进入编辑模式
4、文件底部添加以下两行:
 NDK_ROOT=/home/ndk。这里指你ndk的目录路径
 exportNDK_ROOT
 5、按esc退出,再按:wq保存
-->你可以测试一下有没有安装成功:
 $cd $NDK_ROOT
 $ ./ndk-buildNDK_PROJECT_PATH=$NDK_ROOT/samples/two-libs
-->找到生成的文件就代表安装正常了:
1、如果提示某个文件"Permissiondenied"之类的信息时,执行chmod777 your_filename就行了
2、如果提示找不到'cc1'等信息,执行chmod-R 777 *,就能解决了
-->配置源代码:
在/home/ndk/samples/创建一个FFMPEG文件夹,在里面再新建一个jni文件夹,然后把ffmpeg源码放在jni里面,所以最后ffmpeg源码的路径是:
 /home/ndk/samples/FFMPEG/jni/ffmpeg
1. 在ffmpeg源文件夹下创建一个config.sh,内容如下:
 #!/bin/bash
PREBUILT=/home/xxx/android_NDK/android-ndk-r4b/build/prebuilt/linux-x86/arm-eabi-4.4.0
PLATFORM=/home/xxx/android_NDK/android-ndk-r4b/build/platforms/android-8/arch-arm
./configure--target-os=linux \
--arch=arm\
--enable-version3\
--enable-gpl\
--enable-nonfree\
--disable-stripping\
--disable-ffmpeg\
--disable-ffplay\
--disable-ffserver\
--disable-ffprobe\
--disable-encoders\
--disable-muxers\
--disable-devices\
--disable-protocols\
--enable-protocol=file\
--enable-avfilter\
--disable-network\
--disable-mpegaudio-hp\
--disable-avdevice\
--enable-cross-compile\
--cc=$PREBUILT/bin/arm-eabi-gcc\
--cross-prefix=$PREBUILT/bin/arm-eabi-\
--nm=$PREBUILT/bin/arm-eabi-nm\
--extra-cflags="-fPIC-DANDROID" \
--disable-asm\
--enable-neon\
--enable-armv5te\
--extra-ldflags="-Wl,-T,$PREBUILT/arm-eabi/lib/ldscripts/armelf.x-Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib$PREBUILT/lib/gcc/arm-eabi/4.4.0/crtbegin.o$PREBUILT/lib/gcc/arm-eabi/4.4.0/crtend.o -lc -lm -ldl"
记得PREBUILT和PLATFORM要设置正确,它在你的NDK里面,你可以按自己的填写
2. 然后打开命令窗口,cdffmpeg源文件夹下。
$chmod +x config.sh       /*这个命令是改变config.sh执行权限而已*/
 $./config.sh
如果配置正确的话显示出来的最后两行是这样的:
 License:nonfree and unredistributable
 Creating config.mak and config.h...
3、Configure完成后接下做NDK编译的条件了。
Android的GCC是不支持restrict关键字的,所以把ffmpeg源码下configure生成的config.h文件中的这一行:
 #definerestrict restrict   改成#definerestrict   /*意思就是把后面的restrict去掉*/
如果重新Configure的话记得要把这个关键字去掉。
编辑libavutil/libm.h把其中的static的方法都删除(如果找不到libavutil/libm.h,就表明你的ffmpeg版本不是0.6而是0.5的。)
分别把libavutil、libavcodec、libavformat、libavfilter、libpostproct和libswscale下的Makefile文件中下面两行删除掉:
 include$(SUBDIR)../subdir.mak
 include $(SUBDIR)../config.mak
然后在ffmpeg源文件夹下新建一个av.mk文件,内容如下:(这些不用替换回车)
 #LOCAL_PATH is one of libavutil, libavcodec, libavformat, orlibswscale
#include$(LOCAL_PATH)/../config-$(TARGET_ARCH).mak
 include$(LOCAL_PATH)/../config.mak
OBJS:=
 OBJS-yes :=
 MMX-OBJS-yes :=
 include$(LOCAL_PATH)/Makefile
#collect objects
 OBJS-$(HAVE_MMX) += $(MMX-OBJS-yes)
 OBJS +=$(OBJS-yes)
FFNAME:= lib$(NAME)
 FFLIBS :=$(foreach,NAME,$(FFLIBS),lib$(NAME))
 FFCFLAGS  =-DHAVE_AV_CONFIG_H -Wno-sign-compare -Wno-switch-Wno-pointer-sign
 FFCFLAGS +=-DTARGET_CONFIG=\"config-$(TARGET_ARCH).h\"
ALL_S_FILES:= $(wildcard $(LOCAL_PATH)/$(TARGET_ARCH)/*.S)
 ALL_S_FILES :=$(addprefix $(TARGET_ARCH)/, $(notdir $(ALL_S_FILES)))
ifneq($(ALL_S_FILES),)
 ALL_S_OBJS := $(patsubst%.S,%.o,$(ALL_S_FILES))
 C_OBJS := $(filter-out$(ALL_S_OBJS),$(OBJS))
 S_OBJS := $(filter$(ALL_S_OBJS),$(OBJS))
 else
 C_OBJS := $(OBJS)
 S_OBJS:=
 endif
C_FILES:= $(patsubst %.o,%.c,$(C_OBJS))
 S_FILES := $(patsubst%.o,%.S,$(S_OBJS))
FFFILES:= $(sort $(S_FILES)) $(sort $(C_FILES))
接下来就是从jni文件夹开始写Android.mk文件,如jni文件下新建一个Android.mk,内容如下:
 include$(all-subdir-makefiles)
在ffmpeg下,Android.mk内容如下:
 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 LOCAL_SHARED_LIBRARIES:= libavformat libavcodec libavutil libpostproc libswscalelibavfilter
 LOCAL_MODULE := ffmpeg
 include$(BUILD_SHARED_LIBRARY)
 include $(callall-makefiles-under,$(LOCAL_PATH))
在ffmpeg\libavformat下,Android.mk内容如下:
 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 include$(LOCAL_PATH)/../av.mk
 LOCAL_SRC_FILES :=$(FFFILES)
 LOCAL_C_INCLUDES:=  \
  $(LOCAL_PATH)  \
  $(LOCAL_PATH)/..
 LOCAL_CFLAGS+= $(FFCFLAGS)
 LOCAL_CFLAGS += -include "string.h"-Dipv6mr_interface=ipv6mr_ifindex
 LOCAL_LDLIBS :=-lz
 LOCAL_SHARED_LIBRARIES := libavutil libavcodec
 LOCAL_MODULE:= $(FFNAME)
 include $(BUILD_SHARED_LIBRARY)
在ffmpeg\libavcodec下,Android.mk内容如下:
 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 include$(LOCAL_PATH)/../av.mk
 LOCAL_SRC_FILES :=$(FFFILES)
 LOCAL_C_INCLUDES:=  \
  $(LOCAL_PATH)  \
  $(LOCAL_PATH)/..
 LOCAL_CFLAGS+= $(FFCFLAGS)
 LOCAL_LDLIBS := -lz
 LOCAL_SHARED_LIBRARIES :=libavutil
 LOCAL_MODULE := $(FFNAME)
 include$(BUILD_SHARED_LIBRARY)
在ffmpeg\libavfilter、ffmpeg\libavutil、ffmpeg\libpostproc、ffmpeg\libswscale下的Android,mk文件内容如下:
 /*最主要是下面加红那行不一样*/
 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 include$(LOCAL_PATH)/../av.mk
 LOCAL_SRC_FILES :=$(FFFILES)
 LOCAL_C_INCLUDES:=  \
  $(LOCAL_PATH)  \
  $(LOCAL_PATH)/..
 LOCAL_CFLAGS+= $(FFCFLAGS)
#LOCAL_SHARED_LIBRARIES:=(这行根据下面蓝色的来填写相应的lib)
LOCAL_MODULE:= $(FFNAME)
 include $(BUILD_SHARED_LIBRARY)
----------------------------------------
ffmpeg\libavutil:不需要这一行,直接加#屏蔽掉。
 ffmpeg\libswscale:LOCAL_SHARED_LIBRARIES:=libavutil
 ffmpeg\libavfilter:LOCAL_SHARED_LIBRARIES:=libavutil libswscalelibavcodec
 ffmpeg\libpostproc:LOCAL_SHARED_LIBRARIES:=libavutil
可能编译libavdevice也是用上面这个Android.mk,然后根据提示的错误没改变红色这行就OK了。
最后就是运行ndk-build了:
 $cd $NDK_ROOT
 $ ./ndk-buildNDK_PROJECT_PATH=$NDK_ROOT/samples/FFMPEG
最后生成libavcodec.so、libavutil.so、libavformat.so、libavfilter.so、libswscale.so和libpostproc.so以及libffmpeg.so,你会发现libffmpeg.so只有2K(1599个字节),其实这个文件是没有加载任何东西而编译成的空SO文件,没有任何函数的SO文件。所以不能用,但其它的都可以。估计是没有LOCAL_SRC_FILES的原因。
另外一篇不错的参考文章:http://www.eoeandroid.com/thread-42184-1-1.html,它生成的是静态库
二:生成静态库(.a文件)
-->环境配置
同上
-->源代码配置
1.
在AndroidNDK上建立一個project。
2.
將FFmpeg的sourcecode整包copy到$(PROJECT)/jni底下。
3.
在$(PROJECT)/jni/ffmpeg底下建立一個config.sh:
#!/bin/bash
 PREBUILT=/android-ndk-r4b/build/prebuilt/windows/arm-eabi-4.4.0
 PLATFORM=/android-ndk-r4b/build/platforms/android-8/arch-arm
 ./configure--target-os=linux \
       --arch=arm\
       --enable-version3\
       --enable-gpl\
       --enable-nonfree\
       --disable-stripping\
       --disable-ffmpeg\
       --disable-ffplay\
       --disable-ffserver\
       --disable-ffprobe\
       --disable-encoders\
       --disable-muxers\
       --disable-devices\
       --disable-protocols\
       --enable-protocol=file\
       --enable-avfilter\
       --disable-network\
       --disable-mpegaudio-hp\
       --disable-avdevice\
       --enable-cross-compile\
       --cc=$PREBUILT/bin/arm-eabi-gcc\
       --cross-prefix=$PREBUILT/bin/arm-eabi-\
       --nm=$PREBUILT/bin/arm-eabi-nm\
       --extra-cflags="-fPIC-DANDROID" \
       --disable-asm\
       --enable-neon\
       --enable-armv5te\
       --extra-ldflags="-Wl,-T,$PREBUILT/arm-eabi/lib/ldscripts/armelf.x-Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib$PREBUILT/lib/gcc/arm-eabi/4.4.0/crtbegin.o$PREBUILT/lib/gcc/arm-eabi/4.4.0/crtend.o -lc -lm-ldl"
PREBUILT和PLATFORM應該要符合你自己的配置。
4.
在Cygwin中,$(PROJECT)/jni/ffmpeg底下執行config.sh:
 $./config.sh
 configure會依據config.sh內的設定將config.mak及config.h建立出來。
5.
在剛剛生成的config.h中找到這句:
 #definerestrict restrict
因為Android的gcc並不認得restrict這個keyword,所以把它改寫成:
 #definerestrict
6.
將/libavutil/libm.h中所有的static函式,全都mark起來。
7.
分別修改libavcodec、libavfilter、libavformat、libavutil、libpostproc和libswscale下的Makefile,將下面兩句mark起來:
 include$(SUBDIR)../config.mak
 include$(SUBDIR)../subdir.mak
8.
在$(PROJECT)/jni/ffmpeg下建立一個檔案av.mk,內容如下:
#LOCAL_PATH is one of libavutil, libavcodec, libavformat, orlibswscale
 include $(LOCAL_PATH)/../config.mak
 OBJS:=
 OBJS-yes :=
 MMX-OBJS-yes :=
 include$(LOCAL_PATH)/Makefile
 # collect objects
 OBJS-$(HAVE_MMX)+= $(MMX-OBJS-yes)
 OBJS += $(OBJS-yes)
 FFNAME :=lib$(NAME)
 FFLIBS :=$(foreach,NAME,$(FFLIBS),lib$(NAME))
 FFCFLAGS  =-DHAVE_AV_CONFIG_H -Wno-sign-compare -Wno-switch-Wno-pointer-sign
 FFCFLAGS +=-DTARGET_CONFIG=\"config-$(TARGET_ARCH).h\"
 ALL_S_FILES:= $(wildcard $(LOCAL_PATH)/$(TARGET_ARCH)/*.S)
 ALL_S_FILES :=$(addprefix $(TARGET_ARCH)/, $(notdir $(ALL_S_FILES)))
 ifneq($(ALL_S_FILES),)
 ALL_S_OBJS := $(patsubst%.S,%.o,$(ALL_S_FILES))
 C_OBJS := $(filter-out$(ALL_S_OBJS),$(OBJS))
 S_OBJS := $(filter$(ALL_S_OBJS),$(OBJS))
 else
 C_OBJS := $(OBJS)
 S_OBJS:=
 endif
 C_FILES := $(patsubst %.o,%.c,$(C_OBJS))
 S_FILES:= $(patsubst %.o,%.S,$(S_OBJS))
 FFFILES := $(sort $(S_FILES))$(sort $(C_FILES))
9.
在$(PROJECT)/jni底下修改Android.mk,內容如下:
 include$(all-subdir-makefiles)
10.
在/ffmpeg底下新增一個Android.mk:
LOCAL_PATH:= $(call my-dir)
include$(CLEAR_VARS)
LOCAL_STATIC_LIBRARIES:= libavformat libavcodec libavutil libpostproc libswscale
LOCAL_MODULE:= ffmpeg
include$(BUILD_SHARED_LIBRARY)
include$(call all-makefiles-under,$(LOCAL_PATH))
11.
在/ffmpeg/libavformat底下新增一個Android.mk:
LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 include$(LOCAL_PATH)/../av.mk
 LOCAL_SRC_FILES :=$(FFFILES)
 LOCAL_C_INCLUDES:=            \
        $(LOCAL_PATH)          \
        $(LOCAL_PATH)/..
 LOCAL_CFLAGS+= $(FFCFLAGS)
 LOCAL_CFLAGS += -include "string.h"-Dipv6mr_interface=ipv6mr_ifindex
 LOCAL_LDLIBS :=-lz
 LOCAL_STATIC_LIBRARIES := $(FFLIBS)
 LOCAL_MODULE :=$(FFNAME)
 include $(BUILD_STATIC_LIBRARY)
12.
在/ffmpeg/libavcodec底下新增一個Android.mk:
LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 include$(LOCAL_PATH)/../av.mk
 LOCAL_SRC_FILES :=$(FFFILES)
 LOCAL_C_INCLUDES:=            \
        $(LOCAL_PATH)          \
        $(LOCAL_PATH)/..
 LOCAL_CFLAGS+= $(FFCFLAGS)
 LOCAL_LDLIBS := -lz
 LOCAL_STATIC_LIBRARIES :=$(FFLIBS)
 LOCAL_MODULE := $(FFNAME)
 include$(BUILD_STATIC_LIBRARY)
13.
在libavfilter、libavutil、libpostproc和libswscale底下都分別新增一個Android.mk:
LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
include$(LOCAL_PATH)/../av.mk
LOCAL_SRC_FILES:= $(FFFILES)
LOCAL_C_INCLUDES:= \
$(LOCAL_PATH) \
$(LOCAL_PATH)/..
LOCAL_CFLAGS+= $(FFCFLAGS)
LOCAL_STATIC_LIBRARIES:= $(FFLIBS)
LOCAL_MODULE:= $(FFNAME)
include$(BUILD_STATIC_LIBRARY)
14.
在$(PROJECT)底下執行ndk-build:
 $/android-ndk-r4b/ndk-build
15.
完成,產生出libavcodec.a、libavformat.a、libavutil.a、libpostproc.a、libswscale.a和libffmpeg.so。










