错误信息：
error while loading shared libraries: libva-x11.so.2: cannot open shared object file: No such file or directory
原因是libva-x11.so.2在/usr/local/lib目录中。
将/usr/local/lib添加了/etc/ld.so.conf.d/libxa.conf
执行ldconfig 更新即可。
错误：
error while loading shared libraries: libdc1394.so.22: cannot open shared object file: No such file or directory
解决办法
apt-get install libdc1394-22-dev错误：
error while loading shared libraries: libpng16.so.16: cannot open shared object file: No such file or directory
解决办法：
apt install libpng16-16git clone https://code.videolan.org/videolan/x264.git
cd x264
./configure --disable-asm
platform: X86_64
byte order: little-endian
system: LINUX
cli: yes
libx264: internal
shared: no
static: no
bashcompletion: yes
asm: no
interlaced: yes
avs: avxsynth
lavf: no
ffms: no
mp4: no
gpl: yes
thread: posix
opencl: yes
filters: crop select_every
lto: no
debug: no
gprof: no
strip: no
PIC: no
bit depth: all
chroma format: all
make -j4
make install
下载x264并编译
git clone git://git.videolan.org/x264.git
./configure --enable-shared --enable-static --prefix=/usr
make -j8
make install
解释一下，指定/usr的话，安装好，不用配置路径。
j8的目的是编译起来，用8路进行make，节省编译时间
2 把libx264编译到ffmpeg
./configure --enable-gpl --enable-libx264 --prefix=/root/extest/webMP4/ffmpeg
make -j8
make instal
就可以了
Referenced from:https://blog.csdn.net/dong_beijing/article/details/78366732