BERKELEY MPEG TOOLS (Version 1.0, Release 2; August 1995)Lawrence A. Rowe, Steve Smoot, Ketan Patel, Brian Smith, Kevin Gong, Eugene Hung, Doug Banks, Sam Tze-San Fung, Darryl Brown, and Dan Wallach--------------------Changes since release one:  mpeg_encode - important bug fixes  mpeg_play   - simple user interface added  others - small bugfixes--------------------Computer Science Division-EECS University of California at BerkeleyBerkeley, CA 94720-1776This distribution is a combined release of tools developed atBerkeley and elsewhere for manipulating MPEG-1 video.This release includes the following tools:  mpeg_play - software-only MPEG-1 video decoder  mpeg_encode - software-only MPEG-1 video encoder   mpeg_stat - a bitstream analysis tool   mpeg_blocks - an interactive tool to examine macroblock coding  mpeg_bits - an interactive tool to examine bit allocation to blocksThe package is available at the URL  ftp://mm-ftp.cs.berkeley.edu/pub/multimedia/mpeg/bmt1r1.tar.gzFor more information on MPEG standards and other MPEG software andhardware, see http://www-plateau.cs.berkeley.edu/mpeg/index.html.Other sites where you can find interesting MPEG related softwareand movies are:  ftp://sunsite.unc.edu/pub/multimedia/utilities   ftp://netcom.com:/pub/cf/cfogg/  http://www.acm.uiuc.edu/rml/MpegThe remainder of this file describes each tool including changes,if any, from previous releases and other information about therelease.  In the descriptions below reference is made to papersdescribing various aspects of these programs.  These papers arealso available at the Plateau WWW site (http://www-plateau.cs.berkeley.edu/)or in our FTP site in the directory pub/multimedia/papers.MPEG_PLAY (V2.3)This program decodes and displays an MPEG-1 video stream.  Theprogram has been written to be portable, which means it has notbeen optimized for specific platforms.  The decoder is implementedas a library that will take a video stream and display it in an Xwindow on an 8, 24 or 32 bit deep display.  The main routine issupplied to demonstrate the use of the decoder library.  Severaldithering algorithms are supplied based on the Floyd-Steinberg,ordered dither, and half-toning algorithms that tradeoff qualityand performance.  Neither the library nor the main routine handlereal-time synchronization or audio streams.A paper published at ACM Multimedia 93 describes the decoder andcompares the performance of the program on several platforms (seepub/multimedia/papers/MM93.ps.Z).  An updated version of thiscomparison is included in the file doc/mpegperf.ps in thisdistribution.  This code has also been included in our ContinuousMedia Player (cmplayer) that plays synchronized audio and videoacross a network.  This system adapts to the decoding performanceof the destination machine.  A paper describing these algorithmsand the performance of the system was published at IS&T SPIE 94(see /pub/multimedia/papers/CMMPEG-SPIE94.ps.Z).This release fixes numerous bugs in the player including the motionvector problem that caused problems when playing MPEGs generatedfrom computer-generated animations, the error in the color spaceequations, some IDCT problems, and a number of minor problems withinstallation on platforms with new OS releases.New features have also been implemented, chief of which are the ability to play system layer MPEG streams (discarding audio), gamma correction, and frame rate control.MPEG_ENCODE (V1.5R2)This program generates an MPEG-1 video bitstream given a sequenceof images in an acceptable format (e.g., yuv, ppm, jpeg, etc.).It can be run on one computer (i.e., sequential) or on severalcomputers (i.e., parallel).  Our goal was to produce a portable,easy-to-use encoder that can be used to encode video material fora variety of desktop applications (e.g., video-on-demand).  Theparallelism is done on a sequence of pictures.  In other words,you can spawn one or more children to encode continuous runs ofpictures.  The goal is to allow you to encode using multipleprocessors, think spare cycles on workstations, to speed up theencoding time.  Although performance depends on the speed ofindividual processors, the file system and network, and the P/Bframe search methods, we have encoded 3.75 frames/second on 8 HPSnakes running in parallel as compared with 0.6 frames/second on1 Snake when coding CIF size images.  The encoder has also beenported to an Intel supercomputer (Paragon) on which it has encoded CCIR601 images at 40 frames/second.A paper describing the parallel encoder and our experiments on anetwork of workstations was published at the 1994 Picture CodingSymposium (see /pub/multimedia/papers/mpeg-encode.ps.Z).  A paperdescribing the port to the Intel supercomputer and the performanceexperiments on that system was presented at IS&T SPIE95 (see/pub/multimedia/papers/intelsc-mpeg-encode.ps.Z).  This work wasdone jointly with Ed Delp and his student Ke Shen from Purdue.You can get a copy of the Intel code from /pub/dist/delp/spie95-codingat skynet.ecn.purdue.edu.This release fixed several bugs and added some new features.Specifically, the encoder has been modified to: 1) accept inputimages generated on the fly by another program, 2) generate constantbitrate bitstreams, 3) be much more flexible about input formats,and 4) allow a priori specification of motion vectors or Qscales on amacroblock level, to avoid repetitive motion searches when reencoding.MPEG_STAT (V2.2R2)MPEG_STAT has been modified to gather more statistics (e.g., bitrate, real Q-scale information, detailed motion vector/cbp information,constrained parameter checking, etc.) and fix some bugs. The majorchange (from 2.1) was to add some additional verification checks to helpdetermine the validty of a bitstream including illegal motionvectors and CPB settings, and speed it up even more.MPEG_BLOCKS (V1.0R2)This program is a new tool that allows a user to examine how amovie has been encoded on a picture-by-picture basis.  It showssize statistics on the different frame types and how each macroblockwas coded.  The program also shows the decoded image so you cansee the effect of these coding parameters.The current version of this program only works on systems thatsupport the X Windowing System and Tcl/Tk because it provides auser-friendly GUI.MPEG_BITS (V1.0R2)This program is also new in this release.  It is based on theMPEG_BLOCKS program, but instead of showing block encoding, itshows how many bits were allocated to each block.  It uses the sameGUI interface.MPEG_BITS also allows you to specify a range of blocks that shouldreceive more bits when recoding the sequence.  The mpeg_encoderhas not yet been modified to take this specification, but it willin a future release.ACKNOWLEDGEMENTSWe gratefully thank Hewlett-Packard, Fujitsu, Hitachi, and Philips who provided financial support for this work.  We also want to thank the following people and organizations for their help:    Jef Poskanzer who developed the pbmplus package.      Eiichi Kowashi of Intel and Avideh Zakhor of U.C. Berkeley who    provided valuable suggestions on motion vector searching.    Chad Fogg of Chromatic Research, Inc. who has helped us understand     many issues in MPEG coding and decoding.    Rainer Menes of the Technical University of Munich who     ported previous versions of the Berkeley MPEG encoder and     decoder to the Macintosh. He has provided us with many suggestions     to improve the code.    Robert Safranek of ATT for comments, suggestions, and most of    the code for custom quantization tables.    Jim Boucher of Boston University for jmovie2jpeg.    The San Diego SuperComputing Center for providing facilities    to develop some of the code contained within.    Tom Lane of the Independent JPEG Group who provided us with the basic     inverse DCT code used by our player.  (tom_lane@g.gp.cs.cmu.edu)    Reid Judd of Sun Microsystems who provided advice and assistance.    Todd Brunhoff of NVR who provided advice and assistance.    Toshihiko Kawai of Sony who provided advice and assistance.