Ringtone Creator supports such PCM formats as MP3 and AMR with some help from codecs (coders/decoders) developed by other companies.
Here's the External Codecs configuration window:
One of the requirements for saving your ringtones in MP3 format is configuring MP3 codec. (Another one is presence of the Sound Engine for the purposes of sound synthesis.) We recommend you to use the Lame (it's the name, not a description) codec available for download from 
this web site. Download the file, unzip it to some location and set up the following MP3 Decoder and MP3 Encoder options:
– Decoder / Encoder: choose Lame
– Path: choose the full path to the lame.exe (or how it's called in your operating system).
That's pretty much it.
Compiled codecs: 
Windows, Macintosh.
Ringtone Creator supports three different AMR NB (Adaptive Multi-Rate Narrow Band) codecs: Sony Ericsson, 3GPP and Nokia Multimedia Converter 2.0. Sony Ericsson version of this codec is available as a part of this product: MIKSoft Mobile AMR Converter (we don't endorse ANY software except ours). 3GPP AMR NB Converter's source code is available for download from their web site, so if you feel yourself comfortable with the C programming language, you can build this codec for your platform (Linux, Solaris and a multitude of less popular platforms). Nokia Multimedia Converter 2.0 can be downloaded from Forum Nokia.
Ringtone Creator requires you to provide the same kind of information about the AMR codec you're using: its name and location of the executable file.
Ringtone Creator supports two different AMR WB (Adaptive Multi-Rate Wide Band) codecs: 3GPP AMR WB Converter (available for download from this location) and Nokia Multimedia Converter 2.0. This codec is configured in precisely the same manner as AMR NB.
QCP is a format developed by Qualcomm, Inc.. This format is used in CDMA phones (a promising market). To get the codec, you need to download its binaries for your platform from this location (Windows and Linux are supported).
Unzip the files and point Ringtone Creator to the executable.
To work with AAC ringtones you need to configure AAC codec.
AAC is supported with the help of FAAD decoder and FAAC encoder.
Their source code can be obtained at http://www.audiocoding.com/ and compiled for your platform.
Windows binaries are available for download from http://www.rarewares.org/aac.html
FreeBSD users can install FAAC/FAAD from the ports located here: /usr/ports/audio/faac, /usr/ports/audio/faad.
Or see http://www.freshports.org/audio/faac/ and http://www.freshports.org/audio/faad/
For most operations you don't need these codecs installed, but once you elect to work with PCM files, you'll have to reread this chapter and apply the information given in it. If your PCM file is less than 1 k after conversion – you can be 100% sure that the problem lies in your codecs configuration or that you don't have the Sound Engine plugin properly installed or both.