FFmpeg4.0.2编译一个so文件20200514成功

2020/05/14

环境

  • Ubnutu 18.041STL
  • ndk 路径 /home/wdz/develop/caixingming/android-ndk-r17c

  • vultr虚拟机 /root/poe/android-ndk-r17c

  • 错误1 
    nasm/yasm not found or too old. Use --disable-x86asm for a crippled build
  • 解决办法：安装yasm sudo apt-get install yasm

编译脚本build.sh

#!/bin/bash
export NDK_ROOT=/home/wdz/develop/caixingming/android-ndk-r17c
export SYSROOT=$NDK_ROOT/platforms/android-21/arch-arm/
export TOOLCHAIN=$NDK_ROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
export CPU=armv7-a
#编译后的文件会放置在 当前路径下的android/arm下
export PREFIX=$(pwd)/android/$CPU

FLAGS="-isystem $NDK_ROOT/sysroot/usr/include/arm-linux-androideabi -D__ANDROID_API__=21 -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -mthumb -Wa,--noexecstack -Wformat -Werror=format-security -O0 -fPIC"
INCLUDES="-isystem $NDK_ROOT/sources/cxx-stl/llvm-libc++/include -isystem $NDK_ROOT/sources/android/support/include -isystem $NDK_ROOT/sources/cxx-stl/llvm-libc++abi/include"
export ADDITIONAL_CONFIGURE_FLAG=""

./configure --target-os=linux \
    --prefix=$PREFIX \
    --arch=arm \
    --enable-small \
    --disable-asm \
    --disable-shared \
    --enable-static \
    --disable-programs \
    --disable-ffmpeg \
    --disable-ffplay \
    --disable-ffprobe \
    --disable-stripping \
    --cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
    --enable-cross-compile \
    --sysroot=$SYSROOT \
    --extra-cflags="$FLAGS $INCLUDES" \
    --extra-cflags="-isysroot $NDK_ROOT/sysroot" \
    $ADDITIONAL_CONFIGURE_FLAG

make clean
make
make install

3、报错解决：

  • 报错一: libavcodec/aaccoder.c:803:25: error: expected identifier or ‘(‘ before numeric constant int B0 = 0, B1 = 0; 解决：把 B0 修改为 b0(可以任意改成别的变量名)

  • 报错二:

libavcodec/hevc_mvs.c: In function 'derive_spatial_merge_candidates':
libavcodec/hevc_mvs.c:208:15: error: 'y0000000' undeclared (first use in this function)
 
解决：将libavcodec/hevc_mvs.c文件的变量B0改成b0，xB0改成xb0，yB0改成yb0
  • 错误三
In file included from /home/wdz/develop/caixingming/android-ndk-r17c/sysroot/usr/include/arm-linux-androideabi/asm/termbits.h:19:0,
                 from /home/wdz/develop/caixingming/android-ndk-r17c/sysroot/usr/include/asm-generic/termios.h:21,
                 from /home/wdz/develop/caixingming/android-ndk-r17c/sysroot/usr/include/arm-linux-androideabi/asm/termios.h:19,
                 from /home/wdz/develop/caixingming/android-ndk-r17c/sysroot/usr/include/linux/termios.h:22,
                 from /home/wdz/develop/caixingming/android-ndk-r17c/sysroot/usr/include/sys/ioctl.h:38,
                 from ./libavutil/timer.h:36,
                 from ./libavutil/internal.h:42,
                 from ./libavutil/common.h:491,
                 from ./libavutil/avutil.h:296,
                 from ./libavutil/mem.h:35,
                 from libavcodec/opustab.h:26,
                 from libavcodec/opus_pvq.c:26:
libavcodec/opus_pvq.c: In function 'quant_band_template':
libavcodec/opus_pvq.c:498:9: error: expected identifier or '(' before numeric constant
     int B0 = blocks;


解决办法：1. 进入libavcodec/opus_pvq.c把 B0都改为b0
解决办法：2. 修改/sysroot/usr/include/arm-linux-androideabi/asm/termbits.h:19:0
#define B0的位置，在下边添加一句:
#undef B0

打包成一个so脚本

  • 新建buildso.sh
#!/bin/bash
export NDK_ROOT=/home/wdz/develop/caixingming/android-ndk-r17c
export TOOLCHAIN=$NDK_ROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
export SYSROOT=$NDK_ROOT/platforms/android-21/arch-arm
export PREFIX=./android/armv7-a

# 打包
$TOOLCHAIN/bin/arm-linux-androideabi-ld \
        -rpath-link=$SYSROOT/usr/lib \
        -L$SYSROOT/usr/lib \
        -L$PREFIX/lib \
        -soname libffmpeg.so -shared -nostdlib -Bsymbolic --whole-archive --no-undefined -o \
        $PREFIX/libffmpeg.so \
        libavcodec/libavcodec.a \
        libavfilter/libavfilter.a \
        libavformat/libavformat.a \
        libavutil/libavutil.a \
        libswresample/libswresample.a \
        libswscale/libswscale.a \
        -lc -lm -lz -ldl -llog --dynamic-linker=/system/bin/linker \
        $TOOLCHAIN/lib/gcc/arm-linux-androideabi/4.9.x/libgcc.a
 
  # strip 精简文件
  $TOOLCHAIN/bin/arm-linux-androideabi-strip  $PREFIX/libffmpeg.so
  • sudo sh buildso.so

pic