what is "symbol lookup error" mean ?

narendra1310 · 06-19-2008, 08:10 AM

Hi all,

while running my code i struck on runtime error.

" symbol lookup error: /opt/real/RealPlayer/plugins/rmfformat.so: undefined symbol: _Z25CreateRealMediaFileFormatPP8IUnknown "

I had installed realplayer.rpm and it was working properly. later i removed one plugin named rmfformat.so from the installed directory and inserted same plugin which i compiled from the real player source. then i run the player . i got the above error.

please let me know what was that error.

Thanks

urup · 06-20-2008, 02:28 AM

The error occurs when a module can't find a module function to call.

A module can export functions so that other modules can call them (this is done via EXPORT_SYMBOL).
If the symbol can't be found you get this error.
You can see which symbols are exported in: "/proc/kallsyms"

knudfl · 06-20-2008, 09:52 AM

The "shared object" (= .so) obviously does not play well with the
executable part of RealPlayer. ("/usr/bin/realplay" (link))
So you will probably have to stay with the plugins installed with
your package manager.

You cannot be sure to compile with the exact same conditions as
the original.

Suggest : Delete (or move if you want to save) the plugin.
Uninstall the package that came with the plugin and afterwards
reinstall it. Then it should work again.

Rgds