[mythtv-users] Problems with libmythavcodec: undefined symbol

[R. G. Newbury]

I am missing a library, but I have no idea which one!

mythfrontend: symbol lookup error: /usr/local/lib/libmythavcodec.so.57: 
undefined symbol: x265_api_get_79


I am trying to get a frontend running on Fedora 27. It worked nicely on 
Fedora 25. This was a full 'bare-metal' install. Myth is compiled from 
master (a rather dated version, matching the main mythbox.

BOth the main mythbox and this desktop have this, in /usr/local/lib

[root at tor1 lib]# ls -al libmythavcodec*
lrwxrwxrwx 1 root root       27 Jun 29  2017 libmythavcodec.so -> 
libmythavcodec.so.57.64.100
lrwxrwxrwx 1 root root       27 Jul 15 23:58 libmythavcodec.so.55 -> 
libmythavcodec.so.57.64.100
lrwxrwxrwx 1 root root       27 Jun 29  2017 libmythavcodec.so.57 -> 
libmythavcodec.so.57.64.100
-rwxr-xr-x 1 root root 14450872 Jul 15 23:39 libmythavcodec.so.57.24.102
-rwxr-xr-x 1 root root 12459768 Jun 29  2017 libmythavcodec.so.57.64.100


And I get this on the desktop in the mythfrontend output:
MythPlugin::init() dlerror: libmythavcodec.so.55: cannot open shared 
object file: No such file or directory

The main system comes up, and I can set recordings etc etc. but when I 
attempt to play anything, I get this:

mythfrontend: symbol lookup error: /usr/local/lib/libmythavcodec.so.57: 
undefined symbol: x265_api_get_79

And realelf tells me that, yes, that symbol is undefined in 
libmythavcodec.so.57(.64.100).

Can anyone assist me and point me to the library which provides this 
symbol. I have spent some time trying to match the mythbox' installation 
with the desktop, but no joy...

Geoff