如何用libx265编译用于安卓的libx265？

Question

我已经成功地用libx264(作为静态库)为安卓编译了libx264。但我也想在安卓上的FFmpeg中使用FFmpeg(作为静态库)。所以我做了一些尝试：

首先，通过将log 265的log2函数和posix_memalign函数转换为log函数(用log近似log2)函数和memalign函数(替换posix_memalign并做一些调整)，解决了它们不存在的问题。并通过删除-lpthread文件中的“cmakelist.txt”来解决线程链接问题。

然后，我使用cmake和make成功地编译了libx265(作为静态库)。

我在libx265配置时启用了FFmpeg。但是当配置运行时，它在屏幕上显示“没有使用pkg-config找到libx265”。

我检查了config.log，发现了以下错误消息：

/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(bitstream.cpp.o):bitstream.cpp:typeinfo for x265::BitInterface: error: undefined reference to 'vtable for __cxxabiv1::__class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(bitstream.cpp.o):bitstream.cpp:typeinfo for x265::Bitstream: error: undefined reference to 'vtable for __cxxabiv1::__si_class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(encoder.cpp.o):encoder.cpp:typeinfo for x265::SEIDecodedPictureHash: error: undefined reference to 'vtable for __cxxabiv1::__si_class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(encoder.cpp.o):encoder.cpp:typeinfo for x265::SEIuserDataUnregistered: error: undefined reference to 'vtable for __cxxabiv1::__si_class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(encoder.cpp.o):encoder.cpp:typeinfo for x265::SEIMasteringDisplayColorVolume: error: undefined reference to 'vtable for __cxxabiv1::__si_class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(threading.cpp.o):threading.cpp:typeinfo for x265::Thread: error: undefined reference to 'vtable for __cxxabiv1::__class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(wavefront.cpp.o):wavefront.cpp:typeinfo for x265::JobProvider: error: undefined reference to 'vtable for __cxxabiv1::__class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(slicetype.cpp.o):slicetype.cpp:typeinfo for x265::BondedTaskGroup: error: undefined reference to 'vtable for __cxxabiv1::__class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(frameencoder.cpp.o):frameencoder.cpp:function x265::FrameEncoder::encodeSlice(): error: undefined reference to '__dynamic_cast'
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(frameencoder.cpp.o):frameencoder.cpp:function x265::FrameEncoder::encodeSlice(): error: undefined reference to '__dynamic_cast'
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(frameencoder.cpp.o):frameencoder.cpp:function x265::FrameEncoder::processRowEncoder(int, x265::ThreadLocalData&): error: undefined reference to '__dynamic_cast'
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(frameencoder.cpp.o):frameencoder.cpp:function .LTHUNK2: error: undefined reference to '__dynamic_cast'
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(frameencoder.cpp.o):frameencoder.cpp:typeinfo for x265::FrameEncoder: error: undefined reference to 'vtable for __cxxabiv1::__vmi_class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function
/home/user/ffmpeg-2.8.1/android/arm/lib/libx265.a(sei.cpp.o):sei.cpp:typeinfo for x265::SEI: error: undefined reference to 'vtable for __cxxabiv1::__vmi_class_type_info'
/home/user/ffmpeg-2.8.1/android/arm/bin/../lib/gcc/arm-linux-androideabi/4.9/../../../../arm-linux-androideabi/bin/ld: the vtable symbol may be undefined because the class is missing its key function

我该怎么做才能修好它？

Answer 1

我找到了解决办法。

我需要手动将“libgnustl_static.a”的路径添加到gcc/g++作为参数，这样，编译就会成功。

Answer 2

最近，我刚刚遇到了错误，就像user3032481所说的。

我修改ffmpeg的配置如下所示。

--extra-libs="-lother_libs -L/Users/shutup/Library/Android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/libs/armeabi -lgnustl_static" \

我认为，原因是x265需要c++ rtti功能，但安卓默认的libstdc++不包含它。所以我们需要添加libgnustl_static.a。