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The new home of the FAQ is http://animeusenet.org/wiki/.This site exists only for historical/archival purposes. 11c. MPEG (MPEG1, MPEG2 & (X,S)VCD)MPEG (including MPEG1, MPEG2, VCD & SVCD) [Keikai]MPEG stands for Motion Picture Experts Group. MPEG is a committee charged with developing multimedia compression technologies. They have spawned many multimedia compression formats over the years. All currently popular formats used in AB(M)A are MPEG-derived. To quote the official MPEG web page at http://mpeg.telecomitalialab.com/, "MPEG is a committee of ISO/IEC that is open to experts duly accredited by an appropriate National Standards Body. On average a meeting is attended by more than 300 experts representing more than 200 companies spanning all industry domains with a stake in digital audio, video and multimedia. On average more than 20 countries are represented at a meeting." Because various forms of MPEG all used the .MPG/.MPEG extensions, one must detect the actual format by deducing the format from the information provided by a media player or through utilities designed for this purpose. Technically, .MPG files are similar to .AVI files in that they are also a wrapper format for the streams included within them. MPEG-4 is discussed in its own section. What are MPEG-1 (.MPG, .MPEG, .M1V) files? [Keikai]MPEG1 is the most widely accepted and compatible multimedia format. Due to its age, however, it no longer provides a very efficient quality/filesize ratio. In other words, very large filesizes are necessary to create MPEG1 video of high quality. However, due to its ubiquity, it is still a popular format, particularly when encoded using the VCD specifications. .M1V files are video-only MPEG-1 streams. They are not posted in AB(M)A. MPEG-1 files should be posted to AB(M)A's sister group alt.binaries.anime.vcd (ABAV). What are VCD (.MPG, .DAT) files? [Keikai]VideoCDs (VCDs) were the first standardized format for multimedia video on optical disc. While never popularized in Western cultures, VCDs were very popular in Asia and other parts ot the world. This format allows up to 74 or 80 minutes of MPEG-1 encoded video with a single audio stream to be burned to a compact disc (CD). While VCD players exist, it is more common to play VCDs on compatible DVD players. The best site for information on VCDs is http://www.vcdhelp.com/. Without going into detail, the multimedia streams on a VCD are encoded at a specific constand bitrate in MPEG-1. Furthermore, depending on the region, the resolution is one of two sizes, one for NTSC and one for PAL. Generally, the NTSC VCD format is what is found in AB(M)A. These MPEG files, however, are slightly modified when burned as a VCD, and to represent this the extension is changed. The MPEG file on a VCD has the extension .DAT. Most media players can play .DAT files "as is" or may require that the extension be renamed to .MPG. These .DAT files can be properly converted to normal MPEG-1 files without reencoding using one of several utilities:
While there is very little difference between .DAT files and .MPG files, it is the responsibility of posters to inform the newsgroup when posting which of these two formats they are using. The easiest way to do this is simply to leave the extension intact. It is assumed that a .MPG file is a proper MPEG-1 file and a .DAT file is a VCD modified MPEG-1 file. A VCD .DAT file should not simply be renamed to .MPG before posting without notifying the newsgroup that this has been done. VCDs should be posted to AB(M)A's sister group alt.binaries.anime.vcd (ABAV). What are MPEG-2 (.MPG, .MPEG, .M2V) files? [Keikai, Ryan]MPEG-2 is another extremely popular format worldwide. It is a significant improvement over MPEG-1, primarily because it is variable bitrate and allows for multiple audio streams, however, it has two significant drawbacks. First, like MPEG-1, the quality/bitrate ratio is not very good. MPEG-2 files are usually quite massive, but they do allow for very high quality video as can be evidenced by DVDs. Secondly, decoding MPEG-2 requires a license. Because of this and because this is the format used in DVDs, media players that support MPEG-2 are generally not available for free. The following media players support MPEG-2:
Because these players (as well as MPEG-2 encoding programs) often install a MPEG-2 codec on a system, it is then often possible to play MPEG-2 files using normal media players with some or all of the capabilities of that program. Often, however, there will be quality and/or seeking problems when doing this. .M2V files are video-only MPEG-2 streams. They are not posted in AB(M)A. MPEG-2 files should be posted to AB(M)A's sister group alt.binaries.anime.vcd (ABAV). What are SVCD (.MPG) files? [Keikai]Super VideoCDs (SVCDs) are an extension of the VCD format to allow for MPEG-2 and all of its advantages. They, however, are still burned to CDs and therefore, because the media files are larger, fit even less duration to each CD. Therefore you have a maximum potential of 74 or 80 minutes of multimedia on a SVCD, but it will typically be between 50-60 minutes. Like VCDs, the MPEG data on SVCDs has specific restrictions that it must follow, resolution in particular. The best site for information on SVCDs is http://www.vcdhelp.com/. SVCDs find slightly less support by standalone DVD players. Most MPEG-2 files posted to the anime usenet groups meet the SVCD restrictions and therefore can be burned as SVCDs using the proper burning software. SVCDs should be posted to AB(M)A's sister group alt.binaries.anime.vcd (ABAV). What are XVCDs, XSVCDs, CVDs, and miniDVDs? [Keikai]These uncommon MPEG formats are best described at http://www.vcdhelp.com/. They are not generally posted to the anime usenet groups but, if they were to be, should be posted to AB(M)A's sister group alt.binaries.anime.vcd (ABAV). What are image (.BIN, etc.) files? [Keikai, Gorunova, ed.]Image files are not a multimedia compression standard, but are instead a file containing the exact or near-exact data from a CD or DVD. Because (S)VCDs and DVDs contain other data besides simple the multimedia files, posting simply the MPEG file will leave out some other experiences, such as menus and "extras". Because of this, occasionally images of the original CD is posted to usenet. This is not common nor especially recommended because many AB(M)A denizens are not equiped to easily deal with these. In cases when it is appropriate, however, VCD and SVCD images should be posted to AB(M)A's sister group alt.binaries.anime.vcd (ABAV). DVD Images must NEVER be posted to AB(M)A, ABAV, or ABMAR. DVDs or their contained MPEG-2 files must be reencoded to a more efficient and bandwidth friendly format before posting. Generally, image files are burned directly to CDs through the use of a burning program such as CDRWin or Nero. It is possible to extract files out of an image file with CDMage, ISOBuster, or VCDGear (http://www.vcdgear.net). Macintosh-Specific Information [Gorunova, xo, Yugo Nada, ed.]Macs may need the MPG Quicktime extension to play MPEG files. While it is less of a problem with more recent versions of MacOS, .DAT files may not play properly. If so, use VCDGear (http://www.vcdgear.net) to convert the .DAT into a proper .MPG. .DAT incompatibility seems to have to do with the video hardware on the system. Linux/*NIX-Specific Information [Original, TheMan, ed.]For Linux, check http://bmrc.berkeley.edu/research/mpeg/mpeg_encode.html for Berkeley MPEG Tools. Encodes and Plays. Many other utlities out there. Check freshmeat.net. [TheMan] Also, see mpegTV - http://www.mpegtv.com/download.html Unfortunately it requires a $10 for the "full-featured" version, although a free version is available. The free version includes a time-limited demo of the "full-featured" version (mtv), *AND* includes a unlimited command line version (mtvp). It can play in regular size, zoomed, and FULL screen. It even plays the Tylor movie mpeg that many where unable to play, and VCD (/dev/cdrom, or set by environment variable). Biggest difference in the 2 versions is the availability of a GUI interface to the registered version, fine tuning video, tracking, and fine tuning audio. OBSOLETE INFORMATION:Note: the information below mostly applies to MPEG-1; see the section on MPEG-2/SVCD for details on that format. See also the section on the MPEG-1 related VideoCD (VCD)/dat/bin formats. Questions about mpgs [TheMan]Q. I don't like having all these MPEG parts of a movie. I hate having to watch 10 mins of video then having to open another file! Can I make a 1 big MPEG?A. First off, you don't have to join together a huge MPEG in order to play back a movie continously without human intervention. You can get a nice software player (haven't looked, haven't bothered), or get a DVD player software such as PowerDVD or WinDVD to do it. Both of those softwares support playlist playback. So you can queue up all those MPEGs and then just play them back. I have found WinDVD's playlist playback to be better though, with less noticable interruption during file changes. Some very smart people out there have figured that they can "join" together those many MPEGs into one by using the DOS command "copy /b mpeg1.mpg + mpeg2.mpg bigmpeg.mpg". This goes the same with trying to use WinZip to zip up all the MPEGs in store mode. What is the problem with this? It will seriously screw up the MPEG playback hardware or software because the I/P/B frames are no longer in order. Whats worse is, if you use WinZip to join them, you will have a PK header at the begining of the file. Very smart indeed. I KNOW Media Player can play them back fine, but thats because Media Player is very forgiving. Many other players and editors out there do not. Try sticking the "MPEG" into VirtualDub and you can hope it can crash. If you really want to join together the MPEGs into one, use a utility to do it properly. One that I know of is MPEGJoin, and that can be found at http://extra.newsguy.com/~theprof/Readme.html. Please ensure that when joining the MPEGs that they are the same in spec (bitrate, interleaving, etc). If you join together a MPEG of different specs, some weird stuff can happen. This utility will join together the MPEG by properly interleaving the frames so that it will be compliant to the IEC/ISO spec (whatever number that is) and thus players and utilties will be able to handle the resulting file with little or problem. Q. How come I can't play the MPEG I copied off of a VCD? <insert player here> other than Windows Media Player won't open it!A. If you copied the DAT file straight off of a VCD, and renamed it to .mpg, then that is why you are getting those error messages. Basically, what happens when you burn an MPEG as a VCD is the authoring software (EZCD, Nero) inserts/pads some extra info to the original MPEG on the fly during the burn. The resulting DAT file on the VCD will have a 10-30% size increase (bloat if you think of it). But anyway, because of this extra padded info, it can confuse a crappy MPEG editor or player. The best practice is to actually "dat2mpg" convert it so that you can revert the DAT back to an original MPEG form. You should *always* do this if you have downloaded something off the net (here on ABA or ABMA, or some site) if the person claims it was from a VCD. Do a dat2mpg no matter what so that you can check to be sure it is really an MPEG before you actually do something with that file, such as burning your own VCD. This util, VCDGear can be found from http://www.vcdgear.org. VCDGear 2.0, which was recently released has a GUI interface. While for some of you people who may prefer a command line interface, can use VCDGear 1.5, which was released not long ago also. LinuxFor Linux, check http://bmrc.berkeley.edu/research/mpeg/mpeg_encode.html for Berkeley MPEG Tools. Encodes and Plays. Many other utlities out there. Check freshmeat.net. [TheMan] Also, see mpegTV - http://www.mpegtv.com/download.html Unfortunately it requires a $10 for the "full-featured" version, although a free version is available. The free version includes a time-limited demo of the "full-featured" version (mtv), *AND* includes a unlimited command line version (mtvp). It can play in regular size, zoomed, and FULL screen. It even plays the Tylor movie mpeg that many where unable to play, and VCD (/dev/cdrom, or set by environment variable). Biggest difference in the 2 versions is the availability of a GUI interface to the registered version, fine tuning video, tracking, and fine tuning audio. User Contributed Notes
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