问题
Right now, I have a ffmeg build script which recognizes libx264 and compiles succesfully. I have also compiled x264 and obtained libx264.a library. Both ffmpeg and libx264 are built from source. I can build ffmpeg without libx264 succesfully as well. Below you may find my script which tries to build ffmpeg with libx264.
#!/bin/bash
NDK=~/Android_NDK_r7b
PLATFORM=$NDK/platforms/android-8/arch-arm/
PREBUILT=$NDK/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86
alitan=~/x264/ndk7_build
function build_one
{
./configure --target-os=linux \
--prefix=$PREFIX \
--enable-cross-compile \
--extra-libs="-lgcc " \
--arch=arm \
--cc=$PREBUILT/bin/arm-linux-androideabi-gcc \
--cross-prefix=$PREBUILT/bin/arm-linux-androideabi- \
--nm=$PREBUILT/bin/arm-linux-androideabi-nm \
--sysroot=$PLATFORM \
--extra-cflags=" -I$alitan/include" \
--disable-shared \
--enable-static \
--extra-ldflags=" -L$alitan/lib " \
--enable-version3 \
--enable-gpl \
--disable-doc \
--disable-everything \
--enable-libx264 \
--enable-encoder=libx264 \
$ADDITIONAL_CONFIGURE_FLAG
make clean
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 -soname libffmpeg.so -shared -nostdlib -z,noexecstack -Bsymbolic --whole-archive --no-undefined -o $PREFIX/libffmpeg.so libavcodec/libavcodec.a libavformat/libavformat.a libavutil/libavutil.a libswscale/libswscale.a -lc -lm -lz -ldl -llog --warn-once --dynamic-linker=/system/bin/linker $PREBUILT/lib/gcc/arm-linux-androideabi/4.4.3/libgcc.a
}
#arm v7vfpv3
CPU=armv7-a
OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfpv3-d16 -marm -march=$CPU "
PREFIX=./DONE/$CPU
ADDITIONAL_CONFIGURE_FLAG=
build_one
Above script doesn't give me libx264.a in ffmpeg output builds.Several other scenarios are as follows. If I enable x264 encoder, I get undefined reference errors to some variables in x264.c (in libavcodec). If I enable shared in ffmpeg configure, I get an error which says it can't cd to my prefix directory (no permission issues by the way).
I am using latest releases of ffmpeg and x264 (cloned the git today) and ndk 7. Ubuntu runs on VM, installed on Windows 7. For further details about my adventure of ffmpeg/x264 porting to Android, you may refer here.
What should I do to use libx264 with ffmpeg? I kept on trying this script with different configurations, removed all ffmpeg x264 folders and reinstalled them, but to no avail.
Thanks a lot in advance.
EDIT Below is my x264 build script. It builds fine, gives me the static library and the headers.
export ARM_ROOT=/home/mehmet/Android_NDK_r7b
export ARM_INC=$ARM_ROOT/platforms/android-8/arch-arm/usr/include/
export ARM_LIB=$ARM_ROOT/platforms/android-8/arch-arm/usr/lib/
export ARM_TOOL=$ARM_ROOT/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86
export ARM_LIBO=$ARM_TOOL/lib/gcc/arm-linux-androideabi/4.4.3
export PATH=$ARM_TOOL/bin:$PATH
export PATH=$ARM_TOOL/arm-linux-androideabi/bin:$PATH
export ARM_PRE=arm-linux-androideabi
#tries to build for 4.4.3 toolchain
./configure --prefix=./ndk7_build \
--disable-gpac \
--extra-cflags=" -I$ARM_INC -fPIC -DANDROID -fpic -mthumb-interwork -ffunction-sections -funwind-tables -fstack-protector -fno-short-enums -D__ARM_ARCH_5__ -D__ARM_ARCH_5T__ -D__ARM_ARCH_5E__ -D__ARM_ARCH_5TE__ -Wno-psabi -march=armv5te -mtune=xscale -msoft-float -mthumb -Os -fomit-frame-pointer -fno-strict-aliasing -finline-limit=64 -DANDROID -Wa,--noexecstack -MMD -MP " \
--extra-ldflags=" -nostdlib -Bdynamic -Wl,--no-undefined -Wl,-z,noexecstack -Wl,-z,nocopyreloc -Wl,-soname,/system/lib/libz.so -Wl,-rpath-link=$ARM_LIB,-dynamic-linker=/system/bin/linker -L$ARM_LIB -nostdlib $ARM_LIB/crtbegin_dynamic.o $ARM_LIB/crtend_android.o -lc -lm -ldl -lgcc " \
--cross-prefix=${ARM_PRE}- \
--disable-asm \
--enable-static \
--host=arm-linux \
This is what happens on terminal when i enable libx264 encoder.
STRIP ffmpeg
INSTALL install-progs-yes
INSTALL ffmpeg
INSTALL ffprobe
libavcodec/libavcodec.a(libx264.o): In function `X264_frame':
/home/mehmet/ffmpeg/libavcodec/libx264.c:158: undefined reference to `x264_picture_init'
/home/mehmet/ffmpeg/libavcodec/libx264.c:178: undefined reference to `x264_encoder_reconfig'
/home/mehmet/ffmpeg/libavcodec/libx264.c:189: undefined reference to `x264_encoder_encode'
/home/mehmet/ffmpeg/libavcodec/libx264.c:195: undefined reference to `x264_encoder_delayed_frames'
libavcodec/libavcodec.a(libx264.o): In function `encode_nals':
/home/mehmet/ffmpeg/libavcodec/libx264.c:100: undefined reference to `x264_bit_depth'
libavcodec/libavcodec.a(libx264.o): In function `X264_close':
/home/mehmet/ffmpeg/libavcodec/libx264.c:230: undefined reference to `x264_encoder_close'
libavcodec/libavcodec.a(libx264.o): In function `X264_init':
/home/mehmet/ffmpeg/libavcodec/libx264.c:283: undefined reference to `x264_param_default'
/home/mehmet/ffmpeg/libavcodec/libx264.c:291: undefined reference to `x264_param_default_preset'
/home/mehmet/ffmpeg/libavcodec/libx264.c:313: undefined reference to `x264_param_parse'
/home/mehmet/ffmpeg/libavcodec/libx264.c:448: undefined reference to `x264_param_apply_fastfirstpass'
/home/mehmet/ffmpeg/libavcodec/libx264.c:451: undefined reference to `x264_param_apply_profile'
/home/mehmet/ffmpeg/libavcodec/libx264.c:494: undefined reference to `x264_encoder_open_125'
/home/mehmet/ffmpeg/libavcodec/libx264.c:505: undefined reference to `x264_encoder_headers'
回答1:
https://github.com/guardianproject/android-ffmpeg/blob/master/configure_ffmpeg.sh
look at above link and how eighthave includes L..X264 in his ./ffmpeg/configure...
if u get the correct libs into the search chain for the config step on ffmpeg , then all those undefined refs go away...
回答2:
Well, thanks to Robert's git, I have checked it and it worked just fine. I don't know why but using SYSROOT style build and adding armv7 optimization flags worked. I have produced a binary for ffmpeg linked to x264 with encoder x264 support. Thanks for your help.
来源：https://stackoverflow.com/questions/12222435/libx264-encoder-error-in-ffmpeg-android-build