Hi: This is my first annoying post to HF.
What is the situation with m4a files? Can I transcode wav,cdda, mp3 and the like directly to a format that is compatible with the "send files to ipod as audiobooks"?
Using FAAC and configuring the audiobook encoder settings as necessary (I gather) why are the files still listed as m4a? If all I need to do is rename as m4b should I do it before transcoding to the ipod or let foobar do it?
Does anyone know of an all in one post or wiki about the perils of file type conversion, that would help me to not ask such generic questions about information that is probably available elsewhere. Any tricks or hints would help, as well.

thanks,
Jim

m4b = m4a = mp4

only the extension differs

Thanks Garf, but let me put it this way.

What is the sequence of events: transcoding set up, input file type, output extension and the like to get me from a CD to an audiobook format?

I used EAC to convert from wav to mp3.
I have FAAC in foobar loaded to transcode the files and this is what I get:

INFO (CORE) : startup time: 480 ms
INFO (foo_podclienc) : Transcoded in 30.12 seconds (8.44x)
INFO (CORE) : attempting to edit file info : file://C:\DOCUME~1\papa\LOCALS~1\Temp\foo_pod11823.m4b
WARNING (CORE) : file info update failure on : file://C:\DOCUME~1\papa\LOCALS~1\Temp\foo_pod11823.m4b
WARNING (foo_alac) : demux.cpp : not M4A file
WARNING (foo_alac) : demux.cpp : (top) unknown chunk id: mp42

I get the same thing if the files are already m4a and try to send them to the ipod "as audiobook"

Does anyone have any ideas what's going on?

Thanks,
Jim

It's just an idea, but this might be caused by the fact, that FAAC creates plain AAC files (audio stream only) and not MP4 files. MP4 is a container format which can contain MPEG-4 video (DivX, XviD, x264, ND etc.), MPEG-4 audio (AAC), MP3 and some other formats.
But I'm wondering, why are you transcoding MP3 to AAC. MP3 created by LAME has a better quality then AAC created by FAAC. AFAIK iPod plays MP3s.

Probably because the iPod's ability to bookmark audio books seems limited to AAC files with the .m4b extension.

Yes EAS, mp3 or whatever to AAC ( aka m4a) so that I can change the ext to m4b so that Ipod can bookmark and speed alter playback.
I haven't jumped ship to Itunes 5 because the so called auto conversion from mp3 to m4b only applies to model type LL/A and I have an LL designated model 4G/20Gig. Ergo, the insistence that I'm to get foobar working in this manner.

Oh well, this open source "free" stuff is like having two jobs.

Thanks,
Jim

Please note what I was trying to tell you: AAC != MP4, MP4 = M4A = M4B. AAC is a plain audio stream, it probably needs to be muxed into MP4 container to work with iPod. There is a tool called MP4Box with a GUI called YAMB that can mux MPEG-4 audio and video in MP4 container. You might try it.
So in conclusion MP4 (M4A, M4B) is a container for audio/video/menu/subtitles. MPEG-4 AAC is a sound compression. It is like OGG Vorbis, OGG is a container, Vorbis is a sound compression. You can have M4A file with MP3 (MPEG-1 layer3) compression.

Please note though that the last time I tested, neither iTunes nor iPods like mono .m4b files. iTunes reports them at the wrong length, and if you pause the file on the iPod it locks up and must be forcefully reset. This might have changed since I tried it last, but that was was the situation was a few months ago at least.

Meaning I should be able to put my existing MP3 Audiobooks / Home class lecture recordings, etc into a M4B container that my soon to be acquired 5G iPod will tolerate? The purpose of this is so that my iPod doesn't try to throw an Audiobook into the mix when I'm trying to shuffle the actual music on the pod!

There's a wiki on HA about these confusing container formats.
Foobar may allow shuffle bypass if the extension is m4b, I'm not sure.
In itunes: get info/options/skip when shuffling option will bypass.

Excellent thanks... Pity iTunes forces you to do this on a track per track basis! En mass would have been much more user friendly...

P.S. I put an MP3 file into an MP4 container (via YAMB 1.3.1)... iTunes would have nothing to do with it unfortunately (foobar2000 0.8.3 played it, but not once renamed to M4B)...