mpeg2encode / mpeg2decode                          =========================              MPEG-2 Encoder / Decoder, Version 1.2, July 19, 1996                             Copyright (c) 1996                         MPEG Software Simulation Group                     E-mail:   mssg@mpeg.org  (author contact)                     Web:      http://www.mpeg.org/MSSG/                     FTP:      ftp://ftp.mpeg.org/pub/mpeg/mssg/Contents:1. Overview2. Introduction3. Contacting the MPEG Software Simulation Group4. Availability 5. Installation6. Acknowledgements7. History of the technical report1. Overview===========This directory contains our implementation of an ISO/IEC DIS 13818-2codec.  It converts uncompressed video frames into MPEG-1 and MPEG-2video coded bitstream sequences, and vice versa.The files mpeg2enc.doc and mpeg2dec.doc in the doc/ directory containfurther information about the codec. The directory verify/ containsa small set of verification pictures, a small bitstream, and Unix shell script to automatically test the output of the encoder and decoder.A precompiled version of the programs for Win32s (Windows NT/95) willbe made available later date, although it is trivial to make a consoleapplication from the encoder and decoder with most Win32s compilers(such as Microsoft Visual C++).Subdirectories src/mpeg2enc and src/mpeg2dec contain the source codefor the encoder and decoder, subdirectory par/ contains a couple ofexample encoder parameter files for 25 and 30 frames/sec MPEG-2 andMPEG-1 video.Summary of changes since July 4, 1994 release:This is only the second official release of our MPEG-2 video software.Only minor bug corrections have been added to the encoder.  We still donot implement scalable encoding, as this is mostly useful only foracademic research.The decoder has been updated to meet the final MPEG specification,although the old decoder will still reconstruct Main Profile and MPEG-1bitstreams just fine.  The current decoder implements the mostimportant case of Spatial scalability, as well as SNR and DataPartitioning.  Temporal scalability is not implemented.2. Introduction===============MPEG-2 Video is a generic method for compressed representation of videosequences using a common coding syntax defined in the document ISO/IEC13818 Part 2 by the International Organization for Standardization(ISO) and the International Electrotechnical Commission (IEC), incollaboration with the International Telecommunications Union (ITU) asRecommendation H.262.  The MPEG-2 concept is similar to MPEG-1, butincludes extensions to cover a wider range of applications.The primary application targeted during the MPEG-2 definition processwas the all-digital transmission of interlaced broadcast TV qualityvideo at coded bitrates between 4 and 9 Mbit/sec.  However, the MPEG-2syntax has been found to be efficient for other applications such asthose at higher bit rates and sample rates (e.g. HDTV). The most significant enhancement over MPEG-1 is the addition of syntaxfor efficient coding of interlaced video (e.g. 16x8 block sizes formotion compensation, field dct organization, Dual Prime prediction, etal).  Several other more subtle enhancements (e.g. 10-bit DCT DCprecision, non-linear macroblock scale quantizer, intra VLC tables,improved IDCT mismatch control) were adopted which have a moderate improvement in coding efficiency.... even for progressive video sequences.Other key features of MPEG-2 are the scalable extensions which permitthe division of a continuous video signal into two or more coded bitstreams representing the video at different resolutions (spatial scalability), picture quality (SNR scalability and data partioning), or frame rates (temporal scalability).The MPEG Software Simulation Group is currently developing MPEGsoftware with the purpose of providing aid in understanding the variousalgorithms which comprise an encoder and decoder, and giving a sampleimplementation based on advanced encoding models. The MPEG-2 softwareproject is an on-going development. Since the current version of theencoder already employs a reasonable (and the most popular) subset ofthe MPEG-2 signal coding toolkit (MPEG-1 and MPEG-2 Main Profile), and there appears to be sufficient public interest, we have decided to make a public release of the code.The encoder can also be used for generating good quality constantbitrate MPEG-1 sequences and is (to our knowledge) the first publiclyavailable encoder based on the relatively sophisticated TM5 coding model.3. Contacting the MPEG Software Simulation Group================================================We welcome any project-specific questions, comments, suggestions, bugreports etc. They should be sent to the Internet E-mail address:       mssg@mpeg.orgwhich automatically forwards to the software authors.4. Availability===============The most recent version of the codec source code is available by anonymousftp from:  ftp://ftp.mpeg.org/pub/mpeg/mssg/The directory contains the following files:  mpeg2vidcodec_v12.tar.gz          codec source code and documentation  mpeg2v12.zip                      source code and Win32s executables You need gunzip (GNU zip/unzip) to uncompress the .gz and .zip archives.5. Installation===============mpeg2decode and mpeg2encode have been compiled and tested on the followingplatforms: - SUN SPARCstation 10, SunOS 4.1.3, (gcc compiler) - '386-PC, MSDOS 5.0, djgpp v1.11, gcc v2.5.7 and MS Visual C++ 4.0The source code should compile without major modifications on other 32bit systems with ANSI C compliant compilers. Systems with 16 bit 'int'variables or segmented memory models are not supported.Please report any modifications you had to apply in order to install theprograms on your system to the address mssg@mpeg.org      The encoder and decoder are kept in separate sub-directories,src/mpeg2dec contains the decoder, while src/mpeg2enc contains theencoder sources.  The following installation procedure applies to boththe encoder and the decoder:Step 1: edit Makefile---------------------You may have to set CC to your C compiler and CFLAGS to the flags requiredby the compiler. It is sufficient to set these variables in the top directoryMakefile. They are propagated to the individual Makefiles of the encoderand decoder. Any other changes have to be applied to the individual Makefiles,however.You can compile the decoder with or without X11 output. Please follow theinstructions in the top-level Makefile to activate X Window System support.Step 2: edit src/mpeg2dec/config.h----------------------------------In most cases, no modification should be required. If your C librarydoesn't accept "rb" / "wb" parameters in fopen() (required to disableLF <-> CR/LF conversion on MSDOS systems), change the #defines RB and WBto "r" and "w".Step 3: make------------Type 'make' from the top directory (mpeg2). On a PC with DJGPP installed youhave to enter 'make pc' in the individual source directories to produce.exe files.Step 4: verification--------------------In the mpeg/verify directory, you can verify correct compilation of thecodec by typing 'make test'. No differences should be reported. Theonly comparison which is allowed to fail is between test.m2v andnew.m2v, caused by floating point accuracy dependencies in the forwardDCT.6. Acknowledgements===================Authors of the current release are:  Stefan Eckart    <stefan@chromatic.com>  Chad Fogg        <cfogg@chromatic.com>420to422, 422to444 scaling filters:  Cheung Auyeung   <auyeung@mot.com>Windows 32s port:  Sorin Papuc      <sop@compcore.com>Special thanks are due to - J. Steurer, M. Oepen, IRT (Institut fuer Rundfunktechnik, Muenchen):   for contributing motion estimation speed improvements (distance   computation short-circuit in conjunction with spiral search, cf.   dist1(), fullsearch()) - Tristan Savatier <tristan@mpeg.org> for his help on numerous    improvements, suggestions, and features. Numerous users:   for providing bug reports and Makefiles7. History of Technical Report Project======================================The Technical Report, a document which primarily consists ofa C source code program, was initiated by the MPEG committee to:  - Provide an example of MPEG video syntax being intelligently employed    to generate good quality video bitstreams. - A reference tool for implementors - Aid in understanding the MPEG specification  - decoder which employs full arithmetic accuracy.----End of Readme file