我的问题源于我在启动ffmpeg时遇到的问题.
我已经安装了ffmpeg,它显示为已安装：

whereis ffmpeg 
ffmpeg: /usr/bin/ffmpeg /usr/bin/X11/ffmpeg /usr/share/ffmpeg /usr/share/man/man1/ffmpeg.1.gz

后来,我发现,有些程序依赖于安装本身没有的库,所以我用ldd命令检查了什么是缺失的：

# ldd /usr/bin/ffmpeg
    linux-vdso.so.1 =>  (0x00007fff71fe9000)
    libavfilter.so.0 => not found
    libpostproc.so.51 => not found
    libswscale.so.0 => not found
    libavdevice.so.52 => not found
    libavformat.so.52 => not found
    libavcodec.so.52 => not found
    libavutil.so.49 => not found
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f5f20bdf000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f5f209c0000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f5f205fb000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f5f20f09000)

事实证明,我的ffmpeg从7个图书馆中切断了.我首先想到的是每个库都必须安装,但是我发现,可能会安装一些或全部,但它们的位置对于ffmpeg来说是未知的.
我读到/etc/ld.so.conf和/etc/ld.so.cache包含库的路径,但我很困惑,因为,只有一行

/etc/ld.so.conf
 cat /etc/ld.so.conf
include /etc/ld.so.conf.d/*.conf

但是很长的/etc/ld.so.cache.

我现在处于失去如何进一步调查的地步,
下一步可能是有用的,即使ffmpeg未知其位置,我如何确定是否确实安装了给定的库.

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Pinned packages:

解决方法:

在/usr/lib和/usr/lib64中查找这些库.如果你发现其中一个缺少ffmpeg,请将其符号链接,使其存在于另一个目录中.

您还可以运行“libm.so.6”的查找并查看该文件的位置. ffmpeg很有可能在同一目录中查找缺失的目录.一旦找到它们,就将它们符号化.

如果您的服务器上不存在它们,请安装包含它们的软件包.如果它们包含在ffmpeg包中但您没有看到它们,请尝试重新安装ffmpeg.