FFmpeg DIY warning

[Vangelis forthnet]

>The ever-vigilant Bat Guano has alerted me to a recent change in the git
>HEAD version of FFmpeg that...
>get_iplayer internally uses "-absf aac_adtstoasc" in an
>FFmpeg command line in order to strip out ADTS frame headers when
>creating a M4A file from AAC audio.  This is done primarily for the
>benefit of iTunes, Winamp, WMP, and other media players that...
>What Changed: A commit to the main FFmpeg repository
>on 5 Sep replaced the -{a,v,s}bsf command line options (for audio, video,
>subtitle bitstream filters) with a single -bsf option...

Hello, dinkypumpkin
 I, too, became aware of this change, but through a "trial & error" way: I 
like to try/use the latest updated windows FFmpeg binary for get_iplayer & 
the rest of my conversions (WinFF and/or Avanti used as Win GUIs), I don't 
compile it myself (not because of laziness but inaptitude!), the "providers" 
I use are mainly now these two:
1. http://ffmpeg.zeranoe.com/builds/win32/static/ (note that v0.8 from this 
site is fetched by the latest windows installer), &
2. http://research.m1stereo.tv/ffmpeg/snapshots/.
Version    FFmpeg-git-N-32290-g6fc1299-x86-static.Schwarz.02-Sep-2011 from 
(1) works fine with  get_iplayer, but when I used
FFmpeg-git-N-32355-g4f7dfe1-x86-static.Schwarz.06-Sep-2011, I got this error 
from get_iplayer:

Input #0, aac, from 'D:\Vangelis\iPlayer Recordings/radio.partial.aac':
  Duration: 02:06:31.56, bitrate: 123 kb/s
    Stream #0.0: Audio: aac, 44100 Hz, stereo, s16, 123 kb/s
Unrecognized option 'absf'
Failed to set value 'aac_adtstoasc' for option 'absf'
INFO: Command exit code 1 (raw code = 256)
WARNING: aac conversion failed - retaining aac file
INFO: Recorded D:\Vangelis\iPlayer Recordings/radio.partial.aac
INFO: id3 tagging aac file

and ended up with a tagged (by id3v2-v0.1.2.exe) aac file.
To cut a long story short, I used site (2), which provides daily builds, and 
tried builds between 03-06 Sep, to pinpoint when the change was introduced:
Build FFmpeg-git-N-32310-gb881a2e-x86-static.M1Research.05-Sep-2011 (marked 
on the site as ffmpeg-20110905-n0.8-1375-gb881a2e)
is the last that works as expected, more recent throw up the error.
After your last post in the mailing list, I tracked down the commit 
responsible & it's this one:
http://git.videolan.org/?p=ffmpeg.git;a=commit;h=d821cbe2ffb5c06073b6c841e6d19bc7ca9ae835
It suggests that the change of syntax should be from "-absf aac_adtstoasc" 
to "-bsf:a aac_adtstoasc", and indeed that WORKS with builds after Sep 5th.
However, I noticed on the FFmpeg git repo this most latest commit:
http://git.videolan.org/?p=ffmpeg.git;a=commit;h=cec92fe49a004a2e8b8b8bbba95d756e43cdd93e
which seems to suggest it reinstates former behaviour. Sadly, I'm gonna have 
to wait until tomorrow (or later) for site (2) to upload a more recent build
than the one dated 11-Sep-2011 (FFmpeg-git-N-32452-g6796b82), because this 
one was auto-compiled just an hour before Niedermayer's commit!
Hope all this was useful to the maintainers/developers of get_iplayer!