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INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
ORGANISATION INTERNATIONALE DE NORMALISATION
ISO/IEC JTC1/SC29/WG 11
CODING OF MOVING PICTURES AND ASSOCIATED AUDIO
MPEG92/
Nov. 1992
Source: Davis Pan (Digital Equipment Corporation),
Chairman of the MPEG/audio ad hoc committee on software
simulation
Title: Working Draft of MPEG/Audio Technical Report
Disclaimer of Warranty
These software programs are available to the user without any
license fee or royalty on an "as is" basis. ISO disclaims any and all
warranties, whether express, implied, or statuary, including any
implied warranties or merchantability or of fitness for a particular
purpose. In no event shall ISO be liable for any incidental, punitive,
or consequential damages of any kind whatsoever arising from the
use of these programs.
This disclaimer of warranty extends to the user of these
programs and user's customers, employees, agents, transferees,
successors, and assigns,
ISO does not represent or warrant that the programs furnished
hereunder are free of infringement or any third-party patents,
copyrights or trade secrets.
The purpose of this software is to provide a tool to help in the
learning and understanding of the MPEG/audio compression and
decompression algorithm. It is not an efficient implementation.
Organization of this Report
The main body of this report describes the organization and
use of the software. The listings of the software, sample makefiles,
and test bitstreams are contained in the appendices:
Appendix A contains the source code for the MPEG/audio
software, written in the C programming language. This software has
been run and verified a large variety of computers and operating
systems.
Appendix B contains sample "makefiles" which can be used to
compile the software. Before compiling, please examine the file
common.h to determine if any of the "#define" declarations should be
reactivated by removing it from a comment statement.
Appendix C contains a minimal bitstream test that can be used
to verify the proper operation of the MPEG/audio software. The
bitstream test consists of three bitstreams:
orig.mpg - The original, coded MPEG/audio bitstream
deco.dec - The audio data resulting from decoding orig.mpg
renc.dec - The encoded MPEG/audio bitstream obtained by
encoding deco.dec
The software is functioning properly if the following equations
hold:
a. decoded(orig.mpg) == deco.dec
byte-swapping of deco.dec will be necessary for this
equation to hold for little-endian computers
b. encoded(deco.dec) == renc.mpg
(encode with the default options except for the following:
48 kHz sampling rate and 256 kbits/sec coded bit rate)
If the bitstream tests fail, make sure that the following
variable types have at least the precision listed below:
integer - 16 or 32bits
float - 32 bits
double - 64 bits.
Electronic Distribution
All the data listed above may be obtained in electronic form
(e-mail) by contacting
:
Mr. Frank Laczko
tel: 214-997-3988
FAX: 214-997-5763
e-mail: frank@laczko.ti.com
Other electronic distribution methods may become available
soon. Managers of public access FTP sites are encouraged to make
this software available on their sites.
Organization of the Code
The MPEG/audio Layer 1 and Layer 2 ** software package consists
of:
21 data files tables
8 source files (*.c)
3 definitions files (*.h)
3 test bitstreams
* makefiles
** The layer 3 software is currently work in progress and will be
included in a future revision of this report.
Table 1 illustrates how the encoder and decoder is formed from the
component files. In this table the definition files are enclosed in
parenthesis and listed immediately below the primary source file
which uses them. The data file names are listed within braces and
also placed immediately below the source file which uses them.
Table 1
encoder common decoder
files files files
---------- ------------ ------------
musicin.c common.c musicout.c
encode.c (common.h) decode.c
(encoder.h) {alloc_0} (decoder.h)
{enwindow} {alloc_1} {dewindow}
psy.c, subs.c {alloc_2}
{absthr_0} {alloc_3}
{absthr_1}
{absthr_2}
tonal.c
{1cb0}, {1cb1}, {1cb2}
{2cb0}, {2cb1}, {2cb2}
{1th0}, {1th1}, {1th2}
{2th0}, {2th1}, {2th2}
Running the Software
To run this software, compile the programs to form an encoder
executable file, musicin, and a decoder executable file, musicout.
To run the code type the name of the file followed by a
carriage return. The programs will prompt you to input the
appropriate parameters. The sound input file for the encoder should
be sound data, monophonic or stereophonic, sampled at 32, 44.1, or
48 kHz with 16 bits per sample. For stereophonic data the left
channel sample should precede the right channel sample. The sound
output file of the decoder will be the same format as the sound input
file used by the decoder, except for possible byte order differences
if the encoder and decoder programs are run on different computer
systems which have different byte ordering conventions.
Special notes for MSDOS users:
1. The default bitrate option does not work.
2. The input/output filename defaults not compatible with MSDOS.
3. Use the large memory model for compilation.
Notes on the Software
The encoder and decoder software are configured to output the
coded audio bitstreams as a string of hexadecimal ascii characters.
For greater compression efficiency, compile flag, BS_FORMAT, in
common.h can be switched to configure the bitstream reading and
writing routines to process raw binary bitstreams.
The decoder program has a very crude implementation of
bitstream synchword detection. It may not be able to correctly
decode valid bitstreams which have false synchword patterns in the
ancillary data portion of the bitstream.
Appendix A MPEG/audio Source Code
(included elsewhere)
Appendix B Sample "makefiles"
(included elsewhere)
Appendix C Test Bitstreams
(included elsewhere)
Appendix D List of Contributors
Bill Aspromonte
Shaun Astarabadi
R. Bittner
Karlheinz Brandenburg
W. Joseph Carter
Jack Chang
Mike Coleman
Johnathan Devine
Ernst Eberlein
Dan Ellis
Peter Farrett
Jean-Georges Fritsch
Vlad Fruchter
Hendrik Fuchs
Bernhard Grill
Amit Gulati
Munsi Haque
Chuck Hsiao
Toshiyuki Ishino
Masahiro Iwadare
Earl Jennings
James Johnston
Leon v.d. Kerkhof
Don Lee
Mike Li
Yu-Tang Lin
Soren Neilsen
Simao F. Campos Neto
Mark Paley
Davis Pan
Tan Ah Peng
Kevin Peterson
Juan Pineda
Ernst F. Schroeder
Peter Siebert
Jens Spille
Sam Stewart
Al Tabayoyon
Kathy Wang
Franz-Otto Witte
Douglas Wong
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.