使用 NDK r9 编译ffmpeg

转自：http://wang-peng1.iteye.com/blog/2004897

1. 环境 ubuntu 我的是13.10 ndk r9d x86_64

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

Download bzip2 tarball 下载

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：

Java代码


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;

Java代码


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

Java代码


#!/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

Java代码


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, 在jni文件夹中创建lib文件夹，将.so文件拷入lib文件夹中，添加Android.mk 使用如下内容,

Java代码


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)

8.使用

使用 libraries在Android project’s jni/Android.mk file,

Java代码


LOCAL_PATH := $(call my-dir)



include $(CLEAR_VARS)

LOCAL_SRC_FILES := $(call all-subdir-java-files)



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)

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。

参考：http://blog.csdn.net/cbzhaojay/article/details/8524915

问题2

:libavutil/parseutils.h:158:64: warning: ‘struct tm’ declared inside parameter listlibavutil/parseutils.h:171:8: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘attribute’ before ‘av_timegm’libavutil/parseutils.c:441:64: warning: ‘struct tm’ declared inside parameter
listlibavutil/parseutils.c:441:7: error: conflictingtypes for ‘av_small_strptime’libavutil/parseutils.h:158:7: note: previous declaration of ‘av_small_strptime’ was here

In file included from jni/libavutil/parseutils.c:32:0:

jni/libavutil/parseutils.h:172:64: warning: 'struct tm' declared inside parameter list [enabled by default]

jni/libavutil/parseutils.h:172:64: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]

jni/libavutil/parseutils.h:185:25: warning: 'struct tm' declared inside parameter list [enabled by default]

jni/libavutil/parseutils.c:463:64: warning: 'struct tm' declared inside parameter list [enabled by default]

jni/libavutil/parseutils.c:463:7: error: conflicting types for 'av_small_strptime'

jni/libavutil/parseutils.h:172:7: note: previous declaration of 'av_small_strptime' was here

jni/libavutil/parseutils.c: In function 'av_small_strptime':

jni/libavutil/parseutils.c:485:19: error: dereferencing pointer to incomplete type

jni/libavutil/parseutils.c:491:19: error: dereferencing pointer to incomplete type

jni/libavutil/parseutils.c:497:19: error: dereferencing pointer to incomplete type

jni/libavutil/parseutils.c:503:19: error: dereferencing pointer to incomplete type

jni/libavutil/parseutils.c:509:19: error: dereferencing pointer to incomplete type

jni/libavutil/parseutils.c:515:19: error: dereferencing pointer to incomplete type

解决方法看：

把 ffmpeg/libavutil/time.h更名为avtime.h,

同时修改下面文件中的引用libavutil/time.h为libavutil/avtime.h

ffmpeg/libavformat/avformat.h:211

ffmpeg/libavformat/avio.c:25

ffmpeg/libavformat/hls.c:33

ffmpeg/libavformat/mux.c:39:30

ffmpeg/libavformat/utils.c:40

ffmpeg/libavutil/time.c:36

原因是重复引用了time.h，在parseutils.c和parseutils.h文件中都引用了，而libavutil/time.h也会被编译的时候引用，而<time.h>却使用的是android
ndk工具中的，造成了冲突。