Thanks, Charles.
I am not doing a cross compile. I just want to build it anyway to make it work [😊] 1. This is the error: *************** .../binutils/2.25/centos6-native/da39a3e/bin/ld: .../mylibrary/0.1/gcc-4.9-glibc-2.20/80414d5/lib/libmylibrary.a(mylibrary_file.o): relocation R_X86_64_32 against `.bss' can not be used when making a shared object; recompile with -fPIC .../mylibrary/0.1/gcc-4.9-glibc-2.20/80414d5/lib/libmylibrary.a: error adding symbols: Bad value collect2: error: ld returned 1 exit status make: *** [libavfilter/libavfilter.so.6] Error 1 +status fail (honored) leaving install tree at "/tmp/ext-build-ffmpeg3-trunk-gcc-4.9-glibc-2.20.6KWYXR" "make" returned non-zero status 2 *************** The full building commands are too big and I just copied something (below) I feel important. Please let me know if I missed anything. 2. This is the compile command for building FFmpeg (which is calling my library): CFLAGS='-O3 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector --param=ssp-buffer-size=4 -fno-omit-frame-pointer -momit-leaf-frame-pointer -m64 -mtune=generic -nostdinc -grecord-gcc-switches ... -fPIC' CXXFLAGS='-O3 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector --param=ssp-buffer-size=4 -fno-omit-frame-pointer -momit-leaf-frame-pointer -m64 -mtune=generic -nostdinc -grecord-gcc-switches -isystem/tp2/gcc/4.9.x/centos6-native/108cf83/include ... CXX=g++ ... <some paths ending with "include"> Here, I did not see anything like "Wextra -DDEBUG..." 3. This is the compile command for building my library: CFLAGS='-O3 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector --param=ssp-buffer-size=4 -fno-omit-frame-pointer -momit-leaf-frame-pointer -m64 -mtune=generic -nostdinc -grecord-gcc-switches ... CXXFLAGS='-O3 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector --param=ssp-buffer-size=4 -fno-omit-frame-pointer -momit-leaf-frame-pointer -m64 -mtune=generic -nostdinc -grecord-gcc-switches ... CXX=g++ .. some paths ending with "include" Thanks. Rich ________________________________ 发件人: Libav-user <[email protected]> 代表 Charles <[email protected]> 发送时间: 2016年9月4日 0:00 收件人: This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter. 主题: Re: [Libav-user] 答复: 答复: 答复: 答复: Are there any ways to use a lib (built from C++ OpenCV) in Ffmpeg filter? On 09/03/2016 02:13 PM, R n wrote: > > conf.env['CXXFLAGS'].append('-fPIC') > > conf.env['CXXFLAGS'].append('-DPIC') [...] > > '--extra-libs=-L /lib64 -lstdc++ -lmylibrarytest', > > .../binutils/2.25/centos6-native/da39a3e/bin/ld: > .../mylibrary/0.1/gcc-4.9-glibc-2.20-fb/8fd4fe1/lib/libmylibrary.a(my_file.cpp.o): > relocation R_X86_64_32 against `.bss' can not be used when making a shared > object; recompile with -fPIC -fPIC is for shared objects, you have to compile all the object code with -fPIC to build a shared library. libmylibrary.a is a static lib so you probably should not be using -fPIC The -lstdc++ indicates you are at least linking against it. Are you doing a cross compile? Centos 6 should be gcc 4.4.7ish and I thought 4.9 was Centos 7 > .../mylibrary/0.1/gcc-4.9-glibc-2.20/8fd4fe1/lib/libmylibrary.a: error adding > symbols: Bad value > > So: > 1. C++ etc to make the library > 2. cc -c your_files.c > 3. C++ -llibrary your_files.o > > In these errors: >> .../binutils/2.25/centos6-native/da39a3e/bin/ld: >> .../mylibrary/0.1/gcc-4.9-glibc-2.20/80414d5/lib/libmylibrary.a(mylibrary_file.cpp.o): >> undefined reference to symbol '_ZdlPv@@GLIBCXX_3.4' >> .../libgcc/4.9.x/gcc-4.9-glibc-2.20/024dbc3/lib/libstdc++.so: error adding >> symbols: DSO missing from command line > > “glibcxx” suggests it’s missing the C++ support library, like if you’re > linking with cc instead of c++ compiler. Can you paste just the library compile command, it should look something like this: g++ -g -std=c++0x -Wall -Wextra -DDEBUG -I/.../ some files [...] -lblah -lblah [...] or cc -Wblah blah somefiles -I/.../blah -L/somepath blah blah If you are using cmake, add VERBOSE=1 to see all the commands for each compilation Thanks cco _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user Libav-user Info Page - FFmpeg<http://ffmpeg.org/mailman/listinfo/libav-user> ffmpeg.org This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter. To see the collection of prior postings to the list, visit the Libav-user ...
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