Sorry if this may have been dicussed before, but I couldn't find any other similar post.
Is there a tool that will transcode an M4A to an AAC file? My Phillips expanium won't play an M4A format AAC file, but will play normal AACs, and of course I don't want to recompress them.
Tried searching all over for a tool that could do so, to no avail. Any help would be appreciated

You dont need to transcode them, you can extract the aac file out of the m4a container. There are many software programs which can do this, I personally would use fb2k

afaik the philips player needs adif-aac, i dunno if there exists a tool which can add an adif header to aac bitstreams?

The Phillips Expanium can only read MPEG2-AAC files with the *.aac extention. You can use mp4creator60.exe to do this. Download it from: http://www.rarewares.org/files/mp4/MPEG4IP...r.Utils-1.0.zip

hmm, tried foobar, unless i'm missing something, I don't see how it can extract the tracks out of the files without recompressing them.
however I've tried using mp4creator (found on foobar's distribution page, thanks jen ) to extract the tracks (using "mp4creator60 -extract=1 -aac-old-file-format file.m4a"), the resulting file as reported by foobar is an adts-aac lc stream (supposedly same format as my other aac files that were encoded with nero), but will not play with nullsoft's default mpeg aac decoder for winamp. omitting the -aac-old-file-format results a raw bitstream.
any ideas as what the difference could be?

Foobar hint : you have to use "mp4 utilities" from the context menu - in case you have them installed. (maybe they come only with the special installer, I'm not sure)

Special installer from Case's site includes all the latest goodies:
http://www.saunalahti.fi/~cse/html/foobar.html

If you dont have MP4 Utilities, you can download it here. Then place the file(s) inside you foobar2000 folder!
Then after a Foobar2000 restart you should have a right-click choice for extracting the AAC file from the MP4 container.

Solaris

Not that I'm complaining, (as im a fb2k user) but just for testing purposes, I installed winamp5 with the mp4 plugin, and it wouldnt play any of my mp4 or raw aac files ???

If fb2k is reporting your nero encoded file as (adts-aac lc) and fb2k is reporting your extracted aac files as (adts-aac lc), then you shouldnt have any problems.

But then again, I could be wrong, as you are able to play the nero encoded aac files in your expanium but not the extracted aac files?

Sorry I couldnt be of more help

Have you tried Rarewares version of in_mp4? Also have you removed file assocation for AAC with Nullsoft's in_mp3?

EDIT: Typo

Unfortunately, no AAC file can be extracted from a MP4 file.
All I wanna do is to convert several mp4 files with different bit rates to aac extension.
With foobar2000, one can only convert these files to aac extension in the same bit rate.

Actually, this is only a process of convert but extraction.

mp4box can do this IIRC