无法将FFmpeg C库导入到android中 [英] Unable to port FFmpeg C library into android

问题描述

我完全想做的：访问 ffmpeg.c 文件来修改 int main（int argc，char ** argv）函数到 JNI ，并将ffmpeg的命令作为字符串传递。

我已经尝试将ffmpeg C库移植到android（ARM处理器） 。我遵循以下不同的方法来做到这一点。

第一尝试：使用官方的ffmpeg安装文档。步骤如下

a）git clone git：//source.ffmpeg.org/ffmpeg.git ffmpeg

b）阅读INSTALL文件。

c）使用 build_x264.sh 下载x264库并构建成功。

  NDK = / home / nav / Work / android / ndk 
 PREBUILT = $ NDK / toolchains / arm-linux -androideabi-4.4.3 / prebuilt 
 PLATFORM = $ NDK / platforms / android-8 / arch-arm 
 PREFIX = / home / nav / 28ffmpeg / android-ffmpeg 
 ./configure  - -prefix = $ PREFIX --enable-static --enable-pic --disable-asm --disable-cli --host = arm-linux --cross-prefix = $ PREBUILT / linux-x86 / bin / arm-linux -androideabi- --sysroot = $ PLATFORM 
 make 
 sudo make install 
 sudo ldconfig 
  

d）然后我从（ ffmpeg库 > http://ffmpeg.org/releases/ffmpeg-snapshot.tar.bz2 ）使用 build_android.sh

构建它，

 ＃！/ bin / bash 
 
 NDK = / home / nav / Work / android / ndk 
 PLATFORM = $ NDK / -8 / arch-arm 
 PREBUILT = $ NDK / toolchains / arm-linux-androideabi-4.4.3 / prebuilt / linux-x86 
 PREFIX = / home / nav / 28ffmpeg / android-ffmpeg 
 
函数build_one 
 {
 ./configure --target-os = linux --prefix = $ PREFIX \ 
 --enable-cross-compile \ 
 --enable-runtime-cpudetect \ 
 --disable-asm \ 
 --arch = arm \ 
 --cc = $ PREBUILT / bin / arm-linux-androideabi-gcc \ 
 --cross-prefix = $ PREBUILT / bin / arm-linux-androideabi- \ 
 --disable-剥离\ 
 --nm = $ PREBUILT / bin / arm-linux-androideabi-nm \ 
 --sysroot = $ PLATFORM \ 
 --enable-nonfree \ 
 --enable-version3 \ 
 --disable-everything \ 
 --enable-gpl \ 
 --disable-doc \ 
 --enable- avresample \ 
 --enable-demuxer = rtsp \ 
 --enable-muxer = rtsp \ 
 --disable-ffplay \ 
 --disable-ffserver \ 
 --enable-ffmpeg \ 
  - -disable-ffprobe \ 
 --enable-libx264 \ 
 --enable-encoder = libx264 \ 
 --enable-decoder = h264 \ 
 --enable -protocol = rtp \ 
 --enable-hwaccels \ 
 --enable-zlib \ 
 --disable-devices \ 
 --disable-avdevice \ 
 --extra-cflags = -  I / home / android-ffmpeg / include -fPIC -DANDROID -D__thumb__ -mthumb -Wfatal-errors -Wno-deprecated -mfloat-abi = softfp -mfpu = vfpv3-d16  - marm -march = armv7-a\ 
 --extra-ldflags = -  L / home / android-ffmpeg / lib
 make -j4 install 
 
 $ PREBUILT / bin / arm-linux-androideabi-ar d libavcodec / libavcodec.a inverse.o 
 $ PREBUILT / bin / arm-linux-androideabi-ld -rpath-link = $ PLATFORM / usr / lib -L ​​$ PLATFORM / usr / lib -L ​​$ PREFIX / lib -soname libffmpeg.so -shared -nostdlib -z，noexecstack -Bsymbolic --whole -archive --no-undefined -o $ PREFIX / libffmpeg.so libavcodec / libavcodec.a libavfilter / libavfilter.a libavresample / libavresample.a libavformat / libavformat.a libavutil / libavutil.a libswscale / libswscale.a -lc -lm  - lz -ldl -llog -lx264  -  warn-once --dynamic-linker = / system / bin / linker $ PREBUILT / lib / gcc / arm-linux-androideabi / 4.4.3 / libgcc.a 
} 
 
 build_one 
  

e）最初它的工作原理很好。但是之后错误来了：

  libavformat / libavformat.a（log2_tab.o）:(。 rodata + 0x0）：多个定义`ff_log2_tab'
 libavcodec / libavcodec.a（log2_tab.o）:(。rodata + 0x0）：在这里首先定义
 libavutil / libavutil.a（log2_tab.o） :(。rodata + 0x0）：多个定义`ff_log2_tab'
 libavcodec / libavcodec.a（log2_tab.o）:(。rodata + 0x0）：这里首先定义
 build_android.sh：48：build_one ：未找到
  

结果： libffmpeg.so 没有找到。

第二次尝试：然后我按照 http://dl.dropbox.com/u/22605641/ffmpeg_android/main.html - >构建

a）我从上面的链接下载了Pre-Build libffmpeg.so 。

b）将 libffmpeg.so 添加到 libs / armeabi / 。

c）使 Android.mk

  include $（CLEAR_VARS）
 LOCAL_MODULE：= ffmpeg 
 LOCAL_SRC_FILES：= libffmpeg.so 
包括$（PREBUILT_SHARED_LIBRARY）
 
 LOCAL_PATH：= $（call my-dir）
 
 include $（CLEAR_VARS）
 LOCAL_MODULE：= main 
 LOCAL_STATIC_LIBRARIES + = ffmpeg 
 LOCAL_SRC_FILES：= ffmpeg-test.c 
 include $（BUILD_SHARED_LIBRARY）
  

d）然后，我通过更改其 int，将所有的ndk设置和all.Copy ffmpeg.c 从库更改为 ffmpeg-test.c 主要功能到我的 JNI 功能，并包含所有必需的包含文件。

错误： p>

控制台：

  / home / nav / Work / android / ndk / ndk-build all 
预建：libffmpeg.so< = jni / 
安装：libffmpeg.so => libs / armeabi / libffmpeg.so 
编译thumb：main< = ffmpeg-test.c 
 jni / ffmpeg-test.c：在函数'print_report'中：
 jni / ffmpeg-test .c：1139：94：warning：内置函数log2的不兼容隐式声明[默认启用] 
 SharedLibrary：libmain.so 
 / home / nav / Work / android / ndk / toolchains /arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/ bin / ld：./obj/local/armeabi/objs/main/ffmpeg-test.o：in function check_keyboard_interaction：jni / ffmpeg-test.c：2496：error：undefined reference to'qp_hist'
  

和许多其他未定义的引用.....

告诉我我在哪里错了需要紧急.....

解决方案

https://github.com/guardianproject/android-ffmpeg

在git上查看这个项目，了解更改的线索到'ffmpeg.c.main（）'
我相信这个项目的构建将在自述文件中提及的NDK的发行中正常工作。

注意：

您应该花一些时间与NDK发行版中的所有文档文件，以便您了解该作品的作品。

对于android JNI，'main（）'函数的退出条件通常需要稍微改变。

What i exactly want to-do : Access the ffmpeg.c file to modify the int main(int argc, char **argv) function to JNI and passing the command of ffmpeg as string.

I have tried to port ffmpeg C library to android(ARM processor). I followed following different ways to do this.

1st Try: using official ffmpeg installation documentation. Steps as follows

a) git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg

b) Read the INSTALL file.

c) Download x264 library and build by using build_x264.sh which build successfully.

    NDK=/home/nav/Work/android/ndk
    PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt
    PLATFORM=$NDK/platforms/android-8/arch-arm
    PREFIX=/home/nav/28ffmpeg/android-ffmpeg                
    ./configure --prefix=$PREFIX --enable-static --enable-pic --disable-asm --disable-cli --host=arm-linux --cross-prefix=$PREBUILT/linux-x86/bin/arm-linux-androideabi- --sysroot=$PLATFORM
  make
  sudo make install
  sudo ldconfig

d) Then i download ffmpeg library from (http://ffmpeg.org/releases/ffmpeg-snapshot.tar.bz2) build it by using build_android.sh

#!/bin/bash

NDK=/home/nav/Work/android/ndk
PLATFORM=$NDK/platforms/android-8/arch-arm
PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86
PREFIX=/home/nav/28ffmpeg/android-ffmpeg

function build_one
                {
                ./configure --target-os=linux --prefix=$PREFIX \
                --enable-cross-compile \
                --enable-runtime-cpudetect \
                --disable-asm \
                --arch=arm \
                --cc=$PREBUILT/bin/arm-linux-androideabi-gcc \
                --cross-prefix=$PREBUILT/bin/arm-linux-androideabi- \
                --disable-stripping \
                --nm=$PREBUILT/bin/arm-linux-androideabi-nm \
                --sysroot=$PLATFORM \
                --enable-nonfree \
                --enable-version3 \
                --disable-everything \
                --enable-gpl \
                --disable-doc \
                --enable-avresample \
                --enable-demuxer=rtsp \
                --enable-muxer=rtsp \
                --disable-ffplay \
                --disable-ffserver \
                --enable-ffmpeg \
                --disable-ffprobe \
                --enable-libx264 \
                --enable-encoder=libx264 \
                --enable-decoder=h264 \
                --enable-protocol=rtp \
                --enable-hwaccels \
                --enable-zlib \
                --disable-devices \
                --disable-avdevice \
--extra-cflags="-I/home/android-ffmpeg/include -fPIC -DANDROID -D__thumb__ -mthumb -Wfatal-errors -Wno-deprecated -mfloat-abi=softfp -mfpu=vfpv3-d16 -marm -march=armv7-a" \
                --extra-ldflags="-L/home/android-ffmpeg/lib"
                make -j4 install

$PREBUILT/bin/arm-linux-androideabi-ar d libavcodec/libavcodec.a inverse.o
$PREBUILT/bin/arm-linux-androideabi-ld -rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -L$PREFIX/lib  -soname libffmpeg.so -shared -nostdlib  -z,noexecstack -Bsymbolic --whole-archive --no-undefined -o $PREFIX/libffmpeg.so libavcodec/libavcodec.a libavfilter/libavfilter.a libavresample/libavresample.a libavformat/libavformat.a libavutil/libavutil.a libswscale/libswscale.a -lc -lm -lz -ldl -llog -lx264 --warn-once --dynamic-linker=/system/bin/linker $PREBUILT/lib/gcc/arm-linux-androideabi/4.4.3/libgcc.a
                }

                build_one

e) Initially it works perfectly. But after that error comes:

libavformat/libavformat.a(log2_tab.o):(.rodata+0x0): multiple definition of `ff_log2_tab'
libavcodec/libavcodec.a(log2_tab.o):(.rodata+0x0): first defined here
libavutil/libavutil.a(log2_tab.o):(.rodata+0x0): multiple definition of `ff_log2_tab'
libavcodec/libavcodec.a(log2_tab.o):(.rodata+0x0): first defined here
build_android.sh: 48: build_one: not found

Result: libffmpeg.so not found.

2nd Try: Then I follow steps in http://dl.dropbox.com/u/22605641/ffmpeg_android/main.html-> Builds

a) I downloaded Pre-Build libffmpeg.so from above link.

b) Add libffmpeg.so to libs/armeabi/ .

c) Make Android.mk

include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg
LOCAL_SRC_FILES := libffmpeg.so
include $(PREBUILT_SHARED_LIBRARY)

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := main
LOCAL_STATIC_LIBRARIES += ffmpeg
LOCAL_SRC_FILES := ffmpeg-test.c
include $(BUILD_SHARED_LIBRARY)

d) Then I do all ndk set up and all.Copy ffmpeg.c from library to ffmpeg-test.c by changing its int main function to my JNI functin and include all necessary include files.

Error:

Console:

  /home/nav/Work/android/ndk/ndk-build all 
Prebuilt       : libffmpeg.so <= jni/
Install        : libffmpeg.so => libs/armeabi/libffmpeg.so
Compile thumb  : main <= ffmpeg-test.c
jni/ffmpeg-test.c: In function 'print_report':
jni/ffmpeg-test.c:1139:94: warning: incompatible implicit declaration of built-in function 'log2' [enabled by default]
SharedLibrary  : libmain.so
/home/nav/Work/android/ndk/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/main/ffmpeg-test.o: in function check_keyboard_interaction:jni/ffmpeg-test.c:2496: error: undefined reference to 'qp_hist'

and many other undefined references.....

Tell me where I am getting wrong. Needed Urgently.....

解决方案

https://github.com/guardianproject/android-ffmpeg

look at this project on git for clues on making changes to 'ffmpeg.c.main()' I believe that the build for this project will work fine on release of NDK mentioned in the readme.

Note:

you should spend some time with all the doc files in the NDK distro so that u understand how the make works.

The exit condition of the 'main()' function usually needs to be altered slightly for android JNI .

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