Hi Michael - further information,
I just checked what else I installed to run my installation of get_iplayer.
Compiled all these programs myself - not prebuilt.
(Maybe your PCLinuxOS handles all dependencies automatically, but Slackware doesn't).
1/ Perl comes with Slackware, but I also needed these CPAN
http://www.cpan.org/ modules:
HTML-Parser-3.60
HTML-Tagset-3.20
HTML-Tagset-3.20.tar.gz
Test-Pod-1.26
libwww-perl-5.826
I think Test-Pod needs to be installed first, as it's used by one of the other during a "make test".
2/ rtmpdump-v1.6.
This is superceded by flvstreamer, which I didn't install.
(rtmpdump withdrawn from sourceforge
http://sourceforge.net/ following Adobe complaints).
3/ FFmpeg version r16039 (with yasm-0.7.2 assembler installed first
http://www.tortall.net/projects/yasm/).
4/ I already had MPlayer r29301-4.3.3 installed. Not sure if it's necessary.
Cheers,
Peter