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THE MPEG-FAQ [Version 1.0 - 20. November 1992] ====================================================== PHADE SOFTWARE Leibnizstr. 30, 1000 Berlin 12, GERMANY Inh. Frank Gadegast Fon/Fax: +49 30 3128103 phade@cs.tu-berlin.de =============================================================================== This is my summary about MPEG, nearly 3 month ago I asked for information about MPEG, and these are the results: This summary is devided in seven parts: I | WHAT IS MPEG ? II | PROFESSIONAL SOFTWARE III | PUBLIC-DOMAIN SOFTWARE IV | MAILBOX-ACCESS V | FTP-ACCESS (PD) VI | MAIL-ACCESS (PD-Software and movies) VII | RETRIEVED MAIL VIII | NEWS I add my comments in brackets [], lines (---- or ====) seperate the chapters. Please try and find out more information yourself. I had enough to do by getting and preparing this information. And only bother me with file-request if its not possible for you to get it somewhere else !!! Please send any additional information via fax or e-mail. The fax is only reachable between Mo.-Fr. from 10.00-13.00 and from 15.00-18.30 german time. Phade (Frank Gadegast) =============================================================================== I | WHAT IS MPEG ? =================== From comp.compression Mon Oct 19 15:38:38 1992 ~Sender: news@chorus.chorus.fr Author: Mark Adler <madler@cco.caltech.edu>. [71] Introduction to MPEG (long) What is MPEG? Does it have anything to do with JPEG? Then what's JBIG and MHEG? What has MPEG accomplished? So how does MPEG I work? What about the audio compression? So how much does it compress? What's phase II? When will all this be finished? How do I join MPEG? How do I get the documents, like the MPEG I draft? ------------------------------------------------------------------------------- ~Subject: [71] Introduction to MPEG (long) Q. What is MPEG? A. MPEG is a group of people that meet under ISO (the International Standards Organization) to generate standards for digital video (sequences of images in time) and audio compression. In particular, they define a compressed bit stream, which implicitly defines a decompressor. However, the compression algorithms are up to the individual manufacturers, and that is where proprietary advantage is obtained within the scope of a publicly available international standard. MPEG meets roughly four times a year for roughly a week each time. In between meetings, a great deal of work is done by the members, so it doesn't all happen at the meetings. The work is organized and planned at the meetings. Q. So what does MPEG stand for? A. Moving Pictures Experts Group. Q. Does it have anything to do with JPEG? A. Well, it sounds the same, and they are part of the same subcommittee of ISO along with JBIG and MHEG, and they usually meet at the same place at the same time. However, they are different sets of people with few or no common individual members, and they have different charters and requirements. JPEG is for still image compression. Q. Then what's JBIG and MHEG? A. Sorry I mentioned them. Ok, I'll simply say that JBIG is for binary image compression (like faxes), and MHEG is for multi-media data standards (like integrating stills, video, audio, text, etc.). Q. Ok, I'll stick to MPEG. What has MPEG accomplished? A. So far (as of January 1992), they have completed the "Committee Draft" of MPEG phase I, colloquially called MPEG I. It defines a bit stream for compressed video and audio optimized to fit into a bandwidth (data rate) of 1.5 Mbits/s. This rate is special because it is the data rate of (uncompressed) audio CD's and DAT's. The draft is in three parts, video, audio, and systems, where the last part gives the integration of the audio and video streams with the proper timestamping to allow synchronization of the two. They have also gotten well into MPEG phase II, whose task is to define a bitstream for video and audio coded at around 3 to 10 Mbits/s. Q. So how does MPEG I work? A. First off, it starts with a relatively low resolution video sequence (possibly decimated from the original) of about 352 by 240 points by 30 frames/s (US--different numbers for Europe), but original high (CD) quality audio. The images are in color, but converted to YUV space, and the two chrominance channels (U and V) are decimated further to 176 by 120 pixels. It turns out that you can get away with a lot less resolution in those channels and not notice it, at least in "natural" (not computer generated) images. The basic scheme is to predict motion from frame to frame in the temporal direction, and then to use DCT's (discrete cosine transforms) to organize the redundancy in the spatial directions. The DCT's are done on 8x8 blocks, and the motion prediction is done in the luminance (Y) channel on 16x16 blocks. In other words, given the 16x16 block in the current frame that you are trying to code, you look for a close match to that block in a previous or future frame (there are backward prediction modes where later frames are sent first to allow interpolating between frames). The DCT coefficients (of either the actual data, or the difference between this block and the close match) are "quantized", which means that you divide them by some value to drop bits off the bottom end. Hopefully, many of the coefficients will then end up being zero. The quantization can change for every "macroblock" (a macroblock is 16x16 of Y and the corresponding 8x8's in both U and V). The results of all of this, which include the DCT coefficients, the motion vectors, and the quantization parameters (and other stuff) is Huffman coded using fixed tables. The DCT coefficients have a special Huffman table that is "two-dimensional" in that one code specifies a run-length of zeros and the non-zero value that ended the run. Also, the motion vectors and the DC DCT components are DPCM (subtracted from the last one) coded. Q. So is each frame predicted from the last frame? A. No. The scheme is a little more complicated than that. There are three types of coded frames. There are "I" or intra frames. They are simply a frame coded as a still image, not using any past history. You have to start somewhere. Then there are "P" or predicted frames. They are predicted from the most recently reconstructed I or P frame. (I'm describing this from the point of view of the decompressor.) Each macroblock in a P frame can either come with a vector and difference DCT coefficients for a close match in the last I or P, or it can just be "intra" coded (like in the I frames) if there was no good match. Lastly, there are "B" or bidirectional frames. They are predicted from the closest two I or P frames, one in the past and one in the future. You search for matching blocks in those frames, and try three different things to see which works best. (Now I have the point of view of the compressor, just to confuse you.) You try using the forward vector, the backward vector, and you try averaging the two blocks from the future and past frames, and subtracting that from the block being coded. If none of those work well, you can intra- code the block. The sequence of decoded frames usually goes like: IBBPBBPBBPBBIBBPBBPB... Where there are 12 frames from I to I (for US and Japan anyway.) This is based on a random access requirement that you need a starting point at least once every 0.4 seconds or so. The ratio of P's to B's is based on experience. Of course, for the decoder to work, you have to send that first P *before* the first two B's, so the compressed data stream ends up looking like: 0xx312645... where those are frame numbers. xx might be nothing (if this is the true starting point), or it might be the B's of frames -2 and -1 if we're in the middle of the stream somewhere. You have to decode the I, then decode the P, keep both of those in memory, and then decode the two B's. You probably display the I while you're decoding the P, and display the B's as you're decoding them, and then display the P as you're decoding the next P, and so on. Q. You've got to be kidding. A. No, really! Q. Hmm. Where did they get 352x240? A. That derives from the CCIR-601 digital television standard which is used by professional digital video equipment. It is (in the US) 720 by 243 by 60 fields (not frames) per second, where the fields are interlaced when displayed. (It is important to note though that fields are actually acquired and displayed a 60th of a second apart.) The chrominance channels are 360 by 243 by 60 fields a second, again interlaced. This degree of chrominance decimation (2:1 in the horizontal direction) is called 4:2:2. The source input format for MPEG I, called SIF, is CCIR-601 decimated by 2:1 in the horizontal direction, 2:1 in the time direction, and an additional 2:1 in the chrominance vertical direction. And some lines are cut off to make sure things divide by 8 or 16 where needed. Q. What if I'm in Europe? A. For 50 Hz display standards (PAL, SECAM) change the number of lines in a field from 243 or 240 to 288, and change the display rate to 50 fields/s or 25 frames/s. Similarly, change the 120 lines in the decimated chrominance channels to 144 lines. Since 288*50 is exactly equal to 240*60, the two formats have the same source data rate. Q. You didn't mention anything about the audio compression. A. Oh, right. Well, I don't know as much about the audio compression. Basically they use very carefully developed psychoacoustic models derived from experiments with the best obtainable listeners to pick out pieces of the sound that you can't hear. There are what are called "masking" effects where, for example, a large component at one frequency will prevent you from hearing lower energy parts at nearby frequencies, where the relative energy vs. frequency that is masked is described by some empirical curve. There are similar temporal masking effects, as well as some more complicated interactions where a temporal effect can unmask a frequency, and vice-versa. The sound is broken up into spectral chunks with a hybrid scheme that combines sine transforms with subband transforms, and the psychoacoustic model written in terms of those chunks. Whatever can be removed or reduced in precision is, and the remainder is sent. It's a little more complicated than that, since the bits have to be allocated across the bands. And, of course, what is sent is entropy coded. Q. So how much does it compress? A. As I mentioned before, audio CD data rates are about 1.5 Mbits/s. You can compress the same stereo program down to 256 Kbits/s with no loss in discernable quality. (So they say. For the most part it's true, but every once in a while a weird thing might happen that you'll notice. However the effect is very small, and it takes a listener trained to notice these particular types of effects.) That's about 6:1 compression. So, a CD MPEG I stream would have about 1.25 MBits/s left for video. The number I usually see though is 1.15 MBits/s (maybe you need the rest for the system data stream). You can then calculate the video compression ratio from the numbers here to be about 26:1. If you step back and think about that, it's little short of a miracle. Of course, it's lossy compression, but it can be pretty hard sometimes to see the loss, if you're comparing the SIF original to the SIF decompressed. There is, however, a very noticeable loss if you're coming from CCIR-601 and have to decimate to SIF, but that's another matter. I'm not counting that in the 26:1. The standard also provides for other bit rates ranging from 32Kbits/s for a single channel, up to 448 Kbits/s for stereo. Q. What's phase II? A. As I said, there is a considerable loss of quality in going from CCIR-601 to SIF resolution. For entertainment video, it's simply not acceptable. You want to use more bits and code all or almost all the CCIR-601 data. From subjective testing at the Japan meeting in November 1991, it seems that 4 MBits/s can give very good quality compared to the original CCIR-601 material. The objective of phase II is to define a bit stream optimized for these resolutions and bit rates. Q. Why not just scale up what you're doing with MPEG I? A. The main difficulty is the interlacing. The simplest way to extend MPEG I to interlaced material is to put the fields together into frames (720x486x30/s). This results in bad motion artifacts that stem from the fact that moving objects are in different places in the two fields, and so don't line up in the frames. Compressing and decompressing without taking that into account somehow tends to muddle the objects in the two different fields. The other thing you might try is to code the even and odd field streams separately. This avoids the motion artifacts, but as you might imagine, doesn't get very good compression since you are not using the redundancy between the even and odd fields where there is not much motion (which is typically most of image). Or you can code it as a single stream of fields. Or you can interpolate lines. Or, etc. etc. There are many things you can try, and the point of MPEG II is to figure out what works well. MPEG II is not limited to consider only derivations of MPEG I. There were several non-MPEG I-like schemes in the competition in November, and some aspects of those algorithms may or may not make it into the final standard for entertainment video compression. Q. So what works? A. Basically, derivations of MPEG I worked quite well, with one that used wavelet subband coding instead of DCT's that also worked very well. Also among the worked-very-well's was a scheme that did not use B frames at all, just I and P's. All of them, except maybe one, did some sort of adaptive frame/field coding, where a decision is made on a macroblock basis as to whether to code that one as one frame macroblock or as two field macroblocks. Some other aspects are how to code I-frames--some suggest predicting the even field from the odd field. Or you can predict evens from evens and odds or odds from evens and odds or any field from any other field, etc. Q. So what works? A. Ok, we're not really sure what works best yet. The next step is to define a "test model" to start from, that incorporates most of the salient features of the worked-very-well proposals in a simple way. Then experiments will be done on that test model, making a mod at a time, and seeing what makes it better and what makes it worse. Example experiments are, B's or no B's, DCT vs. wavelets, various field prediction modes, etc. The requirements, such as implementation cost, quality, random access, etc. will all feed into this process as well. Q. When will all this be finished? A. I don't know. I'd have to hope in about a year or less. Q. How do I join MPEG? A. You don't join MPEG. You have to participate in ISO as part of a national delegation. How you get to be part of the national delegation is up to each nation. I only know the U.S., where you have to attend the corresponding ANSI meetings to be able to attend the ISO meetings. Your company or institution has to be willing to sink some bucks into travel since, naturally, these meetings are held all over the world. (For example, Paris, Santa Clara, Kurihama Japan, Singapore, Haifa Israel, Rio de Janeiro, London, etc.) Q. Well, then how do I get the documents, like the MPEG I draft? A. MPEG is a draft ISO standard. It's exact name is ISO CD 11172. The draft consists of three parts: System, Video, and Audio. The System part (11172-1) deals with synchronization and multiplexing of audio-visual information, while the Video (11172-2) and Audio part (11172-3) address the video and the audio compression techniques respectively. You may order it from your national standards body (e.g. ANSI in the USA) or buy it from companies like OMNICOM phone +44 438 742424 FAX +44 438 740154 =============================================================================== II.1 | PROFESSIONAL SOFTWARE ============================= Xing Technology Corporation PO Box 950 Voice: 805-473-0145 456 Carpenter Canyon FAX: 805-473-0147 Arroyo Grande, CA 93420 Xing products include: MPEG Motion video capture/encode and decode. JPEG Photo image encode and decode. Video capture boards and associated software for both JPEG and MPEG. Microsoft Windows Applications, DOS Applications, and Software Developers Kits are available for JPEG and MPEG. --------------------------------------------------------------------------- Check out the latest in Frame Grabber technology, the PC-Hurricane, a realtime true color frame grabber, which can digitize about 500 frames in realtime (25 frames/sec) into Extended Memory (32 MBytes). So it gives you 20 seconds of full-motion video on the PC. These 320 frames can be saved with one command to the harddrive and can then be processed to a MPEG file with just one other command. You can then join several 20 seconds MPEG clips together to a whole MPEG movie with the MPEG utilities. PC-Hurricane, only available from Ingenierbuero Gatz & Hartmann, GERMANY. ------------------------------------------------------------------------------- II.2 | ------- Ingenieurbuero Gatz & Hartmann, Fehrbelliner Str. 32, 1000 Berlin 20, GERMANY Tel: 030- 344 23 66 or 030-375 55 68 FAX: 030- 344 92 79 or 030-375 56 55 email to: leo@zelator.in-berlin.de The MPEG Encoder is available starting from 349.-DM incl. VAT. PC-Hurricane, only available from Ingenierbuero Gatz & Hartmann. It will be available around December 1992 for a price of 699.-DM inclusive 14 % VAT. --------------------------------------------------------------------------- MPEG 2.0 for windows3.x is now available ! It is the digital Video player via a software only solution ! It displays in a 320x240 window under win3.x a realtime decompressed digital video ! Decompression is done only by software and it reaches 30 frames/sec on a 486 PC ! The new version has a very enhanced picture quality, because the compression rate with the encoder can now be adjusted ! The very new thing is the WAV-Sound support ! So if you have a soundcard inside your PC [or the speaker-drv installed !], you will have a real video-clip with accompagning sound ! They currently sell 3 demo disks with the full featured Player, version 2.0 and lots of animations on the disks. It is availbale for 39.-DM over here in Germany, which is 26 US$. --------------------------------------------------------------------------- BTW, the encoder still sells for 349.-DM and the MCI-driver for 199.-DM =============================================================================== III | PUBLIC-DOMAIN-SOFTWARE ============================= ------------------------------------------------------------------------------- III.1 | DOS ------------ The MPEG-Player 'MPLAY.EXE' from Xing Technologies is included in the 'MPEGXING.LZH'-file. ------------------------------------------------------------------------------- III.2 | WINDOWS ---------------- The MPEG-Player 'MPEGXING.LZH' from Xing Technologies. ------------------------------------------------------------------------------- III.3 | X-WINDOWS ------------------ The MPEG-Player 'mpeg-1.0.tar.Z' from Rowe, Patel and Smith at Berkeley. MPEG Video Software Decoder (Version 1.0; Nov 16,1992) Lawrence A. Rowe, Ketan Patel, and Brian Smith Computer Science Division-EECS, Univ. of Calif. at Berkeley This directory contains a public domain MPEG video software decoder. The decoder is implemented as a library that will take a video stream and display it in an X window. The main routine is supplied to demonstrate the use of the decoder library. Several dithering algorithms are supplied based on the Floyd-Steinberg, ordered dither, and half-toning algorithms that tradeoff quality and performance. Neither the library nor the main routine handle real-time synchronization or audio streams. The decoder implements the standard described in the Committee Draft ISO/IEC CD 11172 dated December 6, 1991 which is sometimes refered to as "Paris Format." The code has been compiled and test on the following platforms: HP PA-RISC (HP/UX 8.X, X11R4) (i.e., HP 9000/7XX's) Sun Sparc (SunOS 4.X, X11R5) DECstation 5000 and Alpha If you decide to port the code to a new architecture, please let us know so that we can incorporate the changes into our sources. This directory contains everything required to build and display video. We have included source code, a makefile, installation instructions, and a man page. Data files can be obtained from the same ftp site this was located in. See the INSTALL file for instructions on how to compile and run the decoder. The data files were produced by XING. XING data does not take advantage of P or B frames (ie, frames with motion compensation). Performance of the player on XING data is significantly slower (half or less) than the performance when motion compensated MPEG data is decoded. We are very interested in running the software on other MPEG streams. Please contact us if you have a stream that does not decode correctly. Also, please send us new streams produced by others that do utilize P and B frames. We have established several mailing lists for messages about the decoder: mpeg-list-dist@CS.Berkeley.EDU General information on the decoder for everyone interested should be sent to this list. This should become active after 11/20/92 mpeg-list-request@CS.Berkeley.EDU Requests to join or leave the list should be sent to this address. The subject line should contain the single word ADD or DELETE. mpeg-bugs@CS.Berkeley.EDU Problems, questions, or patches should be sent to this address. Our future plans include porting the decoder to run on other platforms, integrating it into a video playback system that supports real-time synchronization and audio streams, and further experiments to improve the performance of the decoder. Vendors or other organizations interested in supporting this research or discussing other aspects of this project should contact Larry Rowe at Rowe@CS.Berkeley.EDU. ACKNOWLEDGEMENTS: We would like to thank the following people for their help: Tom Lane of the Independent JPEG Group provided us with the basic inverse DCT code used by our player. (tom_lane@g.gp.cs.cmu.edu) Reid Judd of Sun Microsystems provided advise and assistance. Todd Brunhoff of NVR provided advise and assistance. ------------------------------------------------------------------------------- III.4 | DATA ------------- Several data-files (.gl) are known. See the list below in chapter VI. =============================================================================== IV.1 | MAILBOX-ACCESS ====================== This is the phone number of Xing Technologies' BBS: 805-473-2680 (2400b) (USA) ------------------------------------------------------------------------------- IV.2 | ------- These are the phone numbers of Gatz & Hartmann's 7 line support BBS: ++49 30- 462 63 41 (v32bis) ++49 30- 462 64 35 (v32bis) ++49 30- 462 65 38 (v32bis) ++49 30- 462 60 22 (v32 + PEP) ++49 30- 462 61 37 (v32) ++49 30- 462 62 37 (v32) ++49 30- 461 86 50 (v22bis + HST) This is the professional Zelator-ACCESS-BBS system with Internet access. There will be several new MPEG clips and updates of the GENOA 7900 SVGA board drivers, 24 bit ET4000 programing infos,etc... Check it out ! You will enjoy it. Just log in with: guh That means: Gatz und Hartmann. =============================================================================== V.1 | FTP-ACCESS (PD) ======================= There is an MPEG archive site at: phoenix.oulu.fi (130.231.240.17) in the directory /pub/mpeg Here is the current list from /pub/mpeg: -rw-r--r-- 1 12 10 471502 Sep 13 17:36 MPEGXING.LZH -rw-r--r-- 1 12 10 1192 Oct 2 21:48 TUTTIF3D.DOC -rw-r--r-- 1 12 10 502473 Jul 23 21:53 birdisba.mpg -rw-r--r-- 1 12 10 696 Jul 23 22:25 birdisba.txt -rw-r--r-- 1 12 10 233981 Jul 7 21:45 joel.lzh -rw-r--r-- 1 12 10 1137 Jul 7 21:39 joel.txt -rw-r--r-- 1 12 10 292665 Jun 25 22:39 moglie.mpg -rw-r--r-- 1 12 10 439 Jun 25 22:39 moglie.txt -rw-r--r-- 1 12 10 244095 Sep 18 12:42 mpegplay-020792.lha -rw-r--r-- 1 12 10 368955 Sep 23 00:30 mpegplay.zoo -rw-r--r-- 1 12 10 721801 Jun 3 23:42 mpgmovie.lzh -rw-r--r-- 1 12 10 368 Jun 3 23:47 mpgmovie.txt -rw-r--r-- 1 12 10 978660 Sep 13 17:35 raiders.mpg -rw-r--r-- 1 12 10 250937 Jul 4 11:38 rom.mpg -rw-r--r-- 1 12 10 951 Jul 4 11:39 rom.txt -rw-r--r-- 1 12 10 1534405 Jul 3 13:42 sukhoi.mpg -rw-r--r-- 1 12 10 342 Jul 3 13:48 sukhoi.txt -rw-r--r-- 1 12 10 414427 Oct 2 21:45 tuttif3d.lzh Please contact this ftp-site for files before e-mailing to me !!! ------------------------------------------------------------------------------- V.3 | ------ There is an MPEG archive site at: toe.cs.berkeley.edu (128.32.149.117) in the directory /pub/multimedia/mpeg Here is the current list from /pub/mpeg: -rw-r--r-- 1 0 0 3243 Nov 16 20:48 README [See chapter III.3] -rw-r--r-- 1 0 0 502473 Nov 16 17:59 birdisba.mpg -rw-r--r-- 1 0 0 180963 Nov 16 17:59 birdshow.mpg -rw-r--r-- 1 0 0 206417 Nov 16 17:59 birdwalk.mpg -rw-r--r-- 1 0 0 94959 Nov 16 17:59 f16.mpg -rw-r--r-- 1 0 0 315038 Nov 16 17:59 flight.mpg -rw-r--r-- 1 0 0 53411 Nov 16 17:59 micky.mpg -rw-r--r-- 1 0 0 292665 Nov 16 17:59 moglie.mpg -rw-r--r-- 1 0 0 116251 Nov 17 10:03 mpeg-1.0.tar.Z -rw-r--r-- 1 0 0 24657 Nov 16 17:59 perpetu5.mpg -rw-r--r-- 1 0 0 364256 Nov 16 17:59 qume.mpg -rw-r--r-- 1 0 0 250937 Nov 16 17:59 rom.mpg -rw-r--r-- 1 0 0 1534405 Nov 16 17:59 sukhoi.mpg Please contact this ftp-site for files before e-mailing to me !!! ------------------------------------------------------------------------------- V.3 | ------ Gatz & Hartman BBS is now reachable via ftp, between 18.00 - 6.00 german time. Login as 'gast', then look for IBM-Files under File-Sector 14 : IBM_g_und_h zelator.in-berlin.de (192.109.42.11) =============================================================================== VI | MAIL-ACCESS (PD-Software and movies) =========================================== You can retrieve the following files via e-mail. Just put a 'x' between the brackets and send the list back to me. ---- MPEG-UTILITIES ---- MPEGDOS.ZIP 22183 11-16-92 ( ) MPEGWIN.ZIP 209297 11-16-92 ( ) MPEG-1.0.TAR.Z 116251 11-20-92 ( ) ---- MPEG-MOVIES ---- BIRDISBA.MPG 502473 10-19-92 ( ) BIRDSHOW.MPG 180963 06-04-92 ( ) F16.MPG 94959 06-04-92 ( ) FIMPSY.MPG 281960 10-19-92 ( ) FIMPSY50.MPG 240029 10-19-92 ( ) FLIGHT.MPG 315038 5-25-92 ( ) JOEL.MPG 285388 10-19-92 ( ) MICKY.MPG 53411 8-27-92 ( ) MOGLIE.MPG 292665 11-17-92 ( ) QUME.MPG 364256 06-02-92 ( ) Please choose one format you like to get the files in. ( ) As splitted, uuencoded tar-file (pieces < 64k) ( ) As splitted, uuencoded zip-file (pieces < 64k) ( ) As uuencoded tar-file ( ) As uuencoded zip-file ( ) As tar-file ( ) As zip-file Please request only ONE file per sended list !!! =============================================================================== VII | RETRIEVED MAIL ====================== From: roman@multimedia.hq.de Date: Mon Oct 19 14:48:43 1992 Philips CD-I wird ab Anfang naechsten Jahres offiziel Full-Screen, Full-Motion Video koennen. Basis sind MPEG-komprimierte Videos. Die benoetigte Hardware-Erweiterung basiert auf C-Cube, bin aber nicht sicher. Kompression kann softwaremaessig erfolgen. Software existiert fuer SUNs im CD-I-Entwicklerpaket (n x 100.000 DM). Die Rechenzeiten fuer die Komression liegen bei 1:60 bis 1:400, also nichts mit Realzeitkompression. Intel's DVI-Technik kann noch kein MPEG (und das wird wohl auch noch einige Zeit so bleiben). Roman M. Jansen Winkeln Technical Director HQ Multimedia-Systeme GmbH EMail roman@multimedia.hq.de Feldmannstrasze 87 Phone +49 681 50088 0 D-6600 Saarbruecken Fax +49 681 50088 80 [ For our english-folks: He is explaining that Philips will publish a ] [ CD-I packages based on MPEG in spring 93. It requieres addiontional ] [ Hardware, the software cost about 60.000 $, but does no real-time- ] [ compression. Anyway, it will be the first system that integrates MPEG. ] --------------------------------------------------------------------------- From: kpatel@roger-rabbit.cs.berkeley.edu (KETAN DASHARATH PATEL) Subject: Re: Xing's SW, Really MPEG Compression? Date: Thu Nov 19 13:20:35 1992 Unfortunately, it is true. XING data is NOT true MPEG and in fact does a lot of dubious things with its Inverse DCT. XING data is simply a sequence of I-Frames (i.e. no interframe compression is done, no motion vectors, nothing). This amounts to little more than a sequence of JPEG type images. Ketan Patel kpatel@cs.berkeley.edu =============================================================================== VIII | NEWS ============ The MPEG-II-draft is about to arrive next week. It will take me a while to put the changes into this FAQ. --------------------------------------------------------------------------- kpatel@cs.berkeley.edu wrote [and presents hereby something very interesting, something that we all like to see running !!!] We have developed a software MPEG decoder. It handles MPEG data that conforms to the draft standard as of Dec 1991. It has been alpha released last week and will be released to the general public sometime next week if I can get it polished in time. If you would like to recieve more information on how to get it, subscribe to the mailing list mpeg-list@cs.berkeley.edu by doing the following: Send mail to: mpeg-list-request@cs.berkeley.edu with the single word ADD or DELETE in order to join or leave the mailing list. DO NOT SEND JOIN/LEAVE REQUESTS TO MPEG-LIST, SEND THEM TO MPEG-LIST- REQUEST. [See chapter III.3 as well] -----snipp-----------------snipp-------------snipp----------sniopp--------- -----snipp-----------------snipp-------------snipp----------sniopp--------- -----snipp-----------------snipp-------------snipp----------sniopp---------