[MEncoder-users] aconvert (again)

[jegunn]

Hi. I am trying to use aconvert to produce .flac files with added audio 
effects--specifically bs2b crossfeed and equalization for headphone 
listening--from straight flac input. I found in a thread some years ago 
that to produce flac output one needs to specify the output codec thus:

-oac lavc -lavcopts acodec=flac,

which is also the syntax found in the HTML documentation at

http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-enc-libavcodec.html

But it does not seem to work. Just straight flac in, flac out,

aconvert testin.flac testout.flac "-oac lavc -lavcopts acodec=flac"

produces

MEncoder SVN-r32724-snapshot-4.4.5 (C) 2000-2010 MPlayer Team
success: format: 0  data: 0x0 - 0x10444e8
rawvideo file format detected.
Audio only file format detected.
[V] filefmt:65536  fourcc:0x30323449  size:1x1  fps:25.000  ftime:=0.0400
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 44100 Hz, 2 ch, s16le, 488.7 kbit/34.63% (ratio: 61089->176400)
Selected audio codec: [ffflac] afm: ffmpeg (FFmpeg FLAC audio)
==========================================================================
Ignoring video stream!
videocodec: framecopy (1x1 24bpp fourcc=30323449)
Couldn't open codec flac, br=224.

Exiting...

Could somebody tell me what I am missing? It works fine (with the
filter and equalization) for the default "-oac mp3lame". It 
*ALSO* works with other libavcodec codecs, for example

"-oac lavc -lavcopts acodec=ac3"
"-oac lavc -lavcopts acodec=libmp3lame"

I *think* I have all the libraries and devel files installed. I am running 
64-bit Fedora 13 on a dual dual-core Opteron box.

I thought I might have a crippled/defective libavcodec (it was a distro 
install), so I downloaded and built a new copy of ffmpeg, which tells me 
(still) both that the flac format is supported for decoding and encoding 
AND the flac codec is supported for both decoding and encoding:

arianna:Mplayer> ffplay -codecs |& grep flac
  DEA    flac            FLAC (Free Lossless Audio Codec)
arianna:Mplayer> ffplay -formats |& grep flac
  DE flac            raw FLAC

And I still get the self-same message from aconvert that the flac codec 
could not be opened. ac3 and libmp3lame still work. I have no idea what 
the br=224 message means.

So I am completely baffled. Can anyone help me?

I have a couple of further questions about the output chatter from
aconvert when it DOES work, but let us solve first things first.

thanks much in advance

--jim gunn