编译ffmpeg的时候出现ERROR: libx264 not found

最近用Linux编译ffmpeg的时候出现了错误ERROR: libx264 not found

查看config.log原因如下

./x264/libx264.a(opencl.o): In function `x264_opencl_close_library':
opencl.c:(.text+0x572): undefined reference to `dlclose'
./x264/libx264.a(opencl.o): In function `x264_opencl_load_library':
opencl.c:(.text+0x5d7): undefined reference to `dlopen'
opencl.c:(.text+0x5f1): undefined reference to `dlsym'
opencl.c:(.text+0x60e): undefined reference to `dlsym'
opencl.c:(.text+0x62b): undefined reference to `dlsym'
opencl.c:(.text+0x648): undefined reference to `dlsym'
opencl.c:(.text+0x665): undefined reference to `dlsym'
./x264/libx264.a(opencl.o):opencl.c:(.text+0x682): more undefined references to `dlsym' follow
./x264/libx264.a(opencl.o): In function `x264_opencl_load_library':
opencl.c:(.text+0x8fd): undefined reference to `dlclose'
./x264/libx264.a(opencl.o): In function `x264_opencl_lookahead_init':
opencl.c:(.text+0x1841): undefined reference to `dlopen'
opencl.c:(.text+0x185b): undefined reference to `dlsym'
opencl.c:(.text+0x186d): undefined reference to `dlsym'
opencl.c:(.text+0x1881): undefined reference to `dlsym'
opencl.c:(.text+0x1895): undefined reference to `dlsym'
opencl.c:(.text+0x18d4): undefined reference to `dlclose'
collect2: ld returned 1 exit status

查阅资料需要在ffmpeg编译的时候额外指定一下-ldl库

例如进入ffmpeg源码目录

./configure --enable-static --disable-shared 
--enable-encoder=libx264 --enable-libx264 --extra-libs=-ldl

重点在于

--extra-libs=-ldl