320kbps radio audio available via MPEG-DASH

[Vangelis forthnet]

On Sat Jan 9 11:57:11 GMT 2016, Jim web wrote:

> as the copy I sent earier has apparently been 'held' for
> some reason to be checked by the moderator.

Possibly sent inadvertently as rich text,
or you somehow altered the thread title,
or some other fluke thing - second attempt
was successful :-)

> Do I need a fairly new version of ffmpeg as well?

2.95dev uses a native pure Perl HLS (by default)
& MPEG-DASH downloader; FFmpeg is indeed
needed at the last remuxing stage, to produce the
M4A (brand=ipod) audio file.
But your error does not seem to be FFmpeg related...

Using the most-up-to-date 2.95dev main script
(at commit git-65c85be) on Windows,
I ran (from a UK IP):

perl get_iplayer-295latest.pl --pid=b06tvgp1 -i

and the available modes are:
modes:
original: flashstd1,flashstd2,flashlow1,flashlow2,
hlsstd1,hlslow1,dashhigh1,dashhigh2,dashstd1,dashstd2,
dashmed1,dashmed2,dashlow1,dashlow2

Issuing your command proceeds to download file:
perl 
get_iplayer-295latest.pl --pid=b06tvgp1 --radiomode=dashhigh2 --force --no-tag
=>
===========================================
get_iplayer 2.95-dev, Copyright (C) 2008-2010 Phil Lewis
  This program comes with ABSOLUTELY NO WARRANTY; for details 
use --warranty.
  This is free software, and you are welcome to redistribute it under 
certain
  conditions; use --conditions for details.

INFO: Episode-only pid detected
INFO: Trying pid: b06tvgp1 using type: tv
INFO: Trying to stream pid using type tv
INFO: pid not found in tv cache
Matches:

INFO: 1 Matching Programmes
INFO: Checking existence of original version
INFO: dashhigh2 modes will be tried for version original
INFO: Trying dashhigh2 mode to record radio: Compression versus Art - -
INFO: File name prefix = Compression_versus_Art_-__b06tvgp1_original

INFO: Begin recording DASH audio file: D:\Vangelis\iPlayer 
Recordings\Compressio
n_versus_Art_-__b06tvgp1_original.partial.m4a.m4a
Recording:     0.46MB / 63.42MB   537kbps   0.7%, 00:16:00 remaining
===========================================

so not sure what's wrong with your setup...
Include --verbose or --debug in your command,
to possibly get to the bottom of it...
(... and refrain from posting very voluminous
logs here, better use dedicated online
services for that...).

Cheers