1. 环境 ubuntu 我的是13.10 ndk r9 64位
2. 下载ffmpeg http://www.ffmpeg.org/download.html 找到
FFmpeg 2.1.3 "Fourier"
2.1.3 was released on 2014-01-15. It is the latest stable FFmpeg release from the 2.1 release branch, which was cut from master on 2013-10-28. Amongst lots of other changes, it includes all changes from ffmpeg-mt, libav master of 2013-10-27, libav 9 as of 2013-10-27.
It includes the following library versions:
libavutil 52. 48.101 libavcodec 55. 39.101 libavformat 55. 19.104 libavdevice 55. 5.100 libavfilter 3. 90.100 libswscale 2. 5.101 libswresample 0. 17.104 libpostproc 52. 3.100
下载之后 解压到 $NDK/sources 文件夹下面，这是因为编译快捷以及方便使用
3. 找到 ffmpeg-xxx/configure 找到如下几行：
SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)' LIB_INSTALL_EXTRA_CMD='$$(RANLIB) "$(LIBDIR)/$(LIBNAME)"' SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)' SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR) $(SLIBNAME)'
上面几行会导致libavcodec.so.<version> (e.g. libavcodec.so.55),不会被android承认 ，修改为;
SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)' LIB_INSTALL_EXTRA_CMD='$$(RANLIB) "$(LIBDIR)/$(LIBNAME)"' SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)' SLIB_INSTALL_LINKS='$(SLIBNAME)'
4. 复制下面的代码到文本中 并命名为 build_android.sh，注意这个文件应该保存到 ffmpeg-xxx/configure 同一个文件夹下
#!/bin/bash
NDK=$HOME/Desktop/adt/android-ndk-r9
SYSROOT=$NDK/platforms/android-9/arch-arm/
TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.8/prebuilt/linux-x86_64
function build_one
{
./configure \
--prefix=$PREFIX \
--enable-shared \
--disable-static \
--disable-doc \
--disable-ffmpeg \
--disable-ffplay \
--disable-ffprobe \
--disable-ffserver \
--disable-avdevice \
--disable-doc \
--disable-symver \
--cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
--target-os=linux \
--arch=arm \
--enable-cross-compile \
--sysroot=$SYSROOT \
--extra-cflags="-Os -fpic $ADDI_CFLAGS" \
--extra-ldflags="$ADDI_LDFLAGS" \
$ADDITIONAL_CONFIGURE_FLAG
make clean
make
make install
}
CPU=arm
PREFIX=$(pwd)/android/$CPU
ADDI_CFLAGS="-marm"
build_one
注意修改 NDK=$HOME/Desktop/adt/android-ndk-r9 这行
5. 执行
sudo chmod +x build_android.sh ./build_android.sh
6.输出 $NDK/sources/ffmpeg-xxx/android, arm/lib 和arm/include
注意 arm/lib包含了两个 library files (e.g.: libavcodec-55.so) 和 symbolic links (e.g.: libavcodec.so) 我们需要删掉 symbolic links .
7. 让ffmpeg Libraries用在我们的工程下
为了使ffmpeg libraries 可以作为 reusable modules, 需要添加一个文件 $NDK/sources/ffmpeg-xxx/android/arm/Android.mk 使用如下内容,
include $(CLEAR_VARS) LOCAL_MODULE:= libavcodec LOCAL_SRC_FILES:= lib/libavcodec-55.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE:= libavformat LOCAL_SRC_FILES:= lib/libavformat-55.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE:= libswscale LOCAL_SRC_FILES:= lib/libswscale-2.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE:= libavutil LOCAL_SRC_FILES:= lib/libavutil-52.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE:= libavfilter LOCAL_SRC_FILES:= lib/libavfilter-3.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY) include $(CLEAR_VARS) LOCAL_MODULE:= libwsresample LOCAL_SRC_FILES:= lib/libswresample-0.so LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include include $(PREBUILT_SHARED_LIBRARY)
这就是为什么我们把源码放在source文件夹下，ndk会自动寻找
8.使用
使用 libraries在Android project’s jni/Android.mk file,
LOCAL_PATH := $(call my-dir) include $(CLEAR_VARS) LOCAL_MODULE := tutorial03 LOCAL_SRC_FILES := tutorial03.c LOCAL_LDLIBS := -llog -ljnigraphics -lz -landroid LOCAL_SHARED_LIBRARIES := libavformat libavcodec libswscale libavutil include $(BUILD_SHARED_LIBRARY) $(call import-module,ffmpeg-2.0.1/android/arm)
这里你就会发现 我们用到了source中调用了 import-module 使用相对路径去调用。