MAD is a high-quality MPEG audio decoder. It currently supports MPEG-1
as well as the MPEG-2 extension to Lower Sampling Frequencies. All
three audio layers (Layer I, Layer II, and Layer III a.k.a. MP3) are
fully implemented.
MAD does not yet support MPEG-2 multichannel audio (although it should
be backward compatible with such streams) or AAC, nor does it support
the so-called MPEG 2.5 format.
MAD has the following special features:
- 24-bit PCM output
- 100% fixed-point (integer) computation
- completely new implementation based on the ISO/IEC standards
- distributed under the terms of the GNU General Public License (GPL)
The software is distributed as a library (libmad) and command-line
front-end (madplay).
libmikmod is a portable sound library for Unix.
It is able to play the IT, XM, S3M, MTM, 669, STM, ULT, FAR, MED, AMF, DSM,
IMF, GDM, STX, OKT and of course MOD module formats.
libnjb is a C library and API for communicating with the Creative Nomad
JukeBox and Dell DJ digital audio players under BSD, Linux, Mac OS X and
Windows.
libnoise is a portable C++ library that is used to generate coherent
noise, a type of smoothly-changing noise. libnoise can generate
Perlin noise, ridged multifractal noise, and other types of
coherent-noise.
Coherent noise is often used by graphics programmers to generate
natural-looking textures, planetary terrain, and other things. The
mountain scene shown above was rendered in Terragen with a terrain
file generated by libnoise. You can also view some other examples of
what libnoise can do.
In libnoise, coherent-noise generators are encapsulated in classes
called noise modules. There are many different types of noise
modules. Some noise modules can combine or modify the outputs of
other noise modules in various ways; you can join these modules
together to generate very complex coherent noise.
Sidplay 2 is the second in the Sidplay series originally developed by Michael
Schwendt. This version is written by Simon White and is cycle accurate for
improved sound reproduction. Sidplay 2 is capable of playing all C64 mono and
stereo file formats.
Libxmp loads the module and renders the sound as linear PCM samples in a buffer
at rate and format specified by the user. Applications for libxmp include
players, module information extractors, module-to-mp3 renderers, etc.
Adplay is a command line AdLib player using the adplug library. It supports
many AdLib formats such as HSP and HSC.
Aften is an audio encoder which generates compressed audio streams based
on ATSC A/52 specification. This type of audio is also known as AC-3 or
Dolby(R) Digital and is one of the audio codecs used in DVD-Video
content.
A multi-channel MPEG encoder, using the ISO13818 standard and the dist10
source code. Multi-channel files may have up to 6 defined channels:
Left(L), Right(R), Center(C), Left Surround (LS), Right Surround (RS) and
a Low Frequency Enhancement channel (LFE).
ISO13818 defines 5 multi-channel modes (on top of the normal stereo mode),
each of these modes may have an optional LFE channel:
3/2: L, R, C, LS, RS
3/1: L, R, C, mono surround
2/2: L, R, LS, RS
2/1: L, R, mono surround
3/0: L, R, C
The "standard" surround sound encoding of "5.1 channels" is achieved by
using mode 3/2 plus an LFE channel.
A multi-channel MPEG file should decode OK on any MPEG decoder. If the
decoder doesn't recognize the multi-channel extensions, then you'll just
get a stereo file containing a down mix of the 5 channels.
A multi-channel MPEG encoder, using the ISO13818 standard and the dist10
source code. Multi-channel files may have up to 6 defined channels:
Left(L), Right(R), Center(C), Left Surround (LS), Right Surround (RS) and
a Low Frequency Enhancement channel (LFE).
ISO13818 defines 5 multi-channel modes (on top of the normal stereo mode),
each of these modes may have an optional LFE channel:
3/2: L, R, C, LS, RS
3/1: L, R, C, mono surround
2/2: L, R, LS, RS
2/1: L, R, mono surround
3/0: L, R, C
The "standard" surround sound encoding of "5.1 channels" is achieved by
using mode 3/2 plus an LFE channel.
A multi-channel MPEG file should decode OK on any MPEG decoder. If the
decoder doesn't recognize the multi-channel extensions, then you'll just
get a stereo file containing a down mix of the 5 channels.