Super Video CD Overview

 
Note: I have not been able to update this page for a while. I will eventually get to it but for now, you just have to be patient. Meanwhile, I would like to recommend www.vcdhelp.com for up-to-date practical instructions on making SVCDs.
Jukka Aho, 31-May-2001

Contents

  1. History
  2. Current status
  3. Technical features
  4. Playback options
  5. Creating your own SVCDs
  6. Related links

Abstract

This document
  1. outlines the general history, features and applications of the Super Video Compact Disc standard,
  2. discusses about the authoring issues from home user's point of view and
  3. provides some links to related manufacturers, software and further information.
Note: This is an SVCD-only document, not a general beginner's guide to making older kind of (White Book, 2.0) VCDs. If you are only interested in the old VCD format, go see Flexion.Org, Rich Aubin's home page and Kyong Song's MPEG-1 Encoding Infosite.
Feel free to e-mail me any comments, corrections, suggestions, additions or opinions. If you have already encoded, authored and burned your own SVCDs and would like to share some tips with others (or recommend some particular software title or a site related to SVCD), I would be happy to hear from you. Should you come across a broken link, please let me know so I can fix it.

Linking to this document

You are free to link to this document. If you do so, please use the URL <http://www.iki.fi/znark/video/svcd/overview/> This ensures that the link will always work, regardless of the actual physical location of this site.

Acknowledgments

I would like to thank John Asbacher, Rich H. Aubin, Jeffrey X. Carbello, Stephane Cazat, Kevin Cribbs, einnarr, Tony Field, Pierre-Aurelien Georges, Frederic Guigand, Johan Janssen, Jerry F. Jones, Jari Ketola, Kimmo Kinnunen, Michael Kirk, Gerhard Köll, Konstantinos Konstantinides, Johannes Kratz, John Mann, Sebastian Markart, David Martin, Markus Mönig, Thanomsak Liumsuwan, Martin Loose, Peter Melander, Ivan Ricondo, Anssi Saari, Michael Simmons, Laszlo Szakalos, Jim Taylor, Ralf Tossenberger and Peter Wu for providing valuable suggestions, additional information and updates concerning this document.

Parts of the text have been directly borrowed from various CD-ROM and Video CD FAQs all over the web, then edited a bit to fit together. The goal was to make an SVCD-only document, not a general VCD information page. My special thanks go to Jim Taylor, the author of the DVD FAQ for letting me use some of his work as a base for this document. Some of the notions are my own. I like them that way.

1. History

Super Video CD (aka SVCD, Super VCD or Chaoji VCD) is an enhancement to Video CD that was developed by a Chinese government-backed committee of manufacturers and researchers, partly to sidestep DVD technology royalties and partly to create pressure for lower DVD player and disc prices in China. The final SVCD spec, set by the China National Committee of Recording Standards, was announced in September 1998, winning out over C-Cube's China Video Disc (CVD) and HQ-VCD (from the developers of the original Video CD).

As always, the background story is a bit more complicated than how it appears in brief summaries like the above. First of all, why was there such a big interest in creating a new CD-based video disc format for China, at the time when the rest of the world was already preparing to accept DVD as the "next generation" digital video delivery format?

It all comes down to the following three reasons:

There were originally three independent efforts of bringing the next-generation video disc standard to the Chinese market: C-Cube got a healthy head start, mostly because it was already an established subcontractor in the Chinese VCD player market. The company naturally wanted to retain its market leader position also with the 2nd generation video disc technology. Since most of the White Book VCD players were based on C-Cube's MPEG decoder chipset, the company was able to develop its own next-generation standard in close co-operation with major Chinese hardware manufacturers. The development of the CVD specification began in 1997 and the first CVD players were released on the market in June 1998, while SVCD and HQ-VCD specifications were still at a draft stage.

This move apparently created some panic in the SVCD and HQ-VCD camps, especially since creating a national 2nd generation video disc standard of its own was at a high priority in the government's interests.

The result was that the government - which had up until this moment mostly pursued its own efforts, and ignored the competition - changed its position and agreed to back the creators of the rivalling HQ-VCD specification. This agreement was made on the condition that the respective feature sets of HQ-VCD and SVCD would be unified into a single standard that would still go by the name 'SVCD', and that the government-backed committee had a final say on the details. The deal was actually a big win to the Video CD Consortium (i.e. Philips-Sony-Matsushita-JVC) since they were late players in this game to begin with.

The co-operation between Chinese Ministry of Information Industry and Video CD Consortium was announced in July 1998, and the final SVCD spec was released shortly thereafter. Thus, the current SVCD spec is actually a fusion of features taken from the government's original SVCD spec and the VCD Consortium's HQ-VCD spec.

However, most of the big VCD player manufacturers in China were backing C-Cube's CVD standard, and there were already approximately 300 000 to 600 000 CVD players in the distribution channels. It was considered necessary not to alienate C-Cube and the manufacturers who had already put so much effort in the CVD standard. To resolve this problem, the Department of Science and Technology of Ministry of Information Industry forced a compromise in incorporating CVD and SVCD under a single umbrella format called "Chaoji Video CD" in November 1998.

"Chaoji VCD" (which roughly translates to 'Super VCD') is not actually a new disc format, but more like a compatibility specification for players. A Chaoji VCD player must be able to play back at least SVCD, CVD, VCD 2.0, VCD 1.1 and CD-DA discs.

Today, all of the so-called 'SVCD' players in production are actually Chaoji VCD players. Despite the mandatory CVD support, it is conceivable that the actual CVD format will be (already is?) orphaned in favor of SVCD. As far as I know, there are no features in the CVD format that would not also exist in the SVCD specification.

2. Current status

Sample of the official Super Video Compact Disc logoSVCD is currently in the process of IEC standardisation (see IEC document title "IEC 62107"). This means that SVCD is about to become an internationally recognized CD standard (just like Video CD 2.0 or CD-DA already are), although it is uncertain whether it will actually find commercial applications outside China and nearby countries.

SVCD titles are currently commercially available at least in mainland China, Hong Kong, Taiwan, Malaysia, Thailand, Singapore and India (please mail me if you know more).

Philips (the inventor of the original audio CD) has added an SVCD logo to their collection of official Compact Disc logos (see the sample above). Super Video CD specification 1.0 can be ordered from Philips System Standards & Licensing at $200.

Lately, relatively cheap stand-alone DVD / SVCD / VCD / MP3 players have been appearing all over the western world. They are selling like hotcakes. You can find links to some of them in the related links section.

3. Technical features

In terms of video and audio quality, SVCD is in between VCD 2.0 and DVD, using a 2x CD drive to support variable bitrate (VBR) MPEG-2 video up to 2.6 Mbps, and either 1 or 2 MPEG-2 Layer II stereo audio streams (for soundtracks in two different languages). It is also possible to use MPEG-2 Multi-Channel 5.1 surround audio encoding.

SVCD can deliver more than 2 times sharper video images (480x576 for PAL material, 480x480 for NTSC - commonly referred to as a "2/3 D1" resolution) than the previous VCD standard . Because of the increased vertical resolution, the interlaced nature of video signal is now also preserved. This results in smoother-looking motion for any video footage that was originally shot with a field-based video camera (as opposed to frame-based film or a "progressive frame mode" video camera).

SVCD supports 16:9 (anamorphic wide screen) image aspect ratio. (Actually, it has always been possible to store 16:9 material in anamorphic format - even on a VCD 2.0 disc or VHS tape - but maybe some SVCD players can now also tell the TV set to automatically switch to the right mode by using wide screen signalling methods.)

SVCD has extensive support for subtitling and karaoke lyrics color highlighting, neither of which were possible in VCD 2.0. An SVCD video stream can contain up to four independent subtitling channels for different languages. The subtitles are overlaid on the top of the video image in real time, which allows turning them on and off at will. Since the subtitles are stored as bitmap graphics, they are not tied to any particular script or character set.

Additionally, SVCD standard supports HTML style hyperlinks, still images (480x576 or 704x576 for PAL, 480x480 or 704x480 for NTSC), playlists/slideshows, multi-level hierarchical menus and chapters (indexing).

To sum it all up: SVCD discs can be used to deliver karaoke or music videos, movies, home videos, still image slide shows, product catalogs and games much the same way as VCD 2.0 discs. However, SVCD standard is not a direct superset of VCD 2.0 standard. It is not possible to use VCD 2.0 frame sizes or MPEG-1 video if you want to create a standard SVCD disc.

The typical running time of an SVCD disc (with full resolution and quality) is about 35-45 minutes, although it can be extended to over 70 minutes by compromising image and sound quality.

4. Playback options

4.1 Stand-alone SVCD/VCD players

Stand-alone SVCD/VCD players are widely available in Far East. In most cases they are able to play at least SVCD, Interactive VCD, VCD 2.0, VCD 1.1, CD-i and CD-DA formats. Some of them even support MP3 CD-ROMs.

SVCD/VCD players cannot play DVDs, since they are not based on DVD drives. However, some models can be 'upgraded' to become a DVD player by swapping the CD drive with a DVD drive. This is due to the fact that most SVCD players use basically the same MPEG-2 engine and processor as their DVD counterparts.

As commercially produced SVCD titles will probably only be available in Far East, it is not very likely that stand-alone SVCD/VCD players would be released outside of China and nearby countries.

4.2 Stand-alone SVCD-compatible DVD video players

From technical viewpoint, it is relatively easy to make any DVD video player compatible with the SVCD standard. Most players would only require a firmware update from the manufacturer.

Asian manufacturers have indeed been shipping SVCD-compatible DVD players for their local markets quite a long time now. However, in Europe - and especially in the US - the situation has been quite different. People have occasionally had a very hard time even finding a VCD 2.0 compatible player, let alone one that would play back such an 'exotic' and relatively unknown format as SVCD is.

Now the tides are changing. OEM manufacturers from Far East have lately been bombarding both Europe and North America with a surge of relatively cheap "no-name" DVD players, based on standard PC components. These technological marvels are selling like hotcakes right now, mostly due their low price and the alluring MP3 CD-ROM playback capability. However, there is yet another good reason for buying them: they also support SVCDs!

It is still uncertain whether SVCD compatibility - or MP3 playback capability, for that matter - will become a widely-supported feature in mainstream European/American DVD players. Nonetheless, now that so many people already have the necessary SVCD equipment, they are surely going to experiment a lot more with creating their own SVCDs.

If you are interested in purchasing a DVD player, you should ask your local retailer first if they have any SVCD-compatible models available, or if they can order one for you. If not, see the related links section below. There are many good SVCD-compatible DVD players available - why settle for anything less?

Note: If you are planning on creating your own SVCDs and viewing them on an SVCD-compatible DVD player, ensure that the player can read CD-R media (i.e. has two lasers), or at least CD-RW media. Some DVD players can only read factory-made (aluminum, "silver") CD media.

Note #2: There are some DVD players that support SVCD even if it does not say so anywhere in the manual. Usually the salespersons do not know anything about this kind hidden capability, and they are also very likely to be totally unaware and ignorant about that such a compact disc standard exists. In order not to miss these players, take an SVCD test disc with you when you go shopping. (VCD 2.0 and MP3 test discs could also come handy.)

4.3 Multimedia PCs

SVCDs can be read in any CD-XA compatible CD-ROM drive that runs with at least 2x speed (i.e. any modern CD-ROM drive will do). A Pentium-II 350 MHz level multimedia PC (or equivalent) can possibly decode SVCDs in real time with mere software. Slower machines may require an additional MPEG-2 decoder card. There are SVCD-compatible software players available in the related links section below.

5. Creating your own SVCDs

Note: I have recently authored and burned my first home-made SVCD, which plays back without a hitch in my stand-alone SMC VP-601K SVCD player. So have the others. Creating SVCDs is not voodoo or black magic anymore. After you have read this introductory stuff, simply go to the related links section and start reading the tutorials offered there. Also check out the MPEG encoders and SVCD authoring programs, and The Super Video CD FAQ. A good place for discussion about MPEG encoding and SVCD authoring is the
Overall image quality seems to be very much as expected - much sharper than with VCD 2.0 - but in high-motion scenes, the image gets blocky very easily. Maybe this is a problem with bbMPEG, though - it does not seem to have the same kind of powerful pre-filtering capabilities as e.g. the Panasonic MPEG-1 Encoder has (or then again, it might be that I just don't know how to tweak it properly yet).
 

Update #2: There are some options buried deep in bbMPEG's advanced options that deal with encoding fields-based (i.e. interlaced) image data. It would seem appropriate to fiddle with these if you're encoding from an interlaced source. Mind you, almost any footage that has been shot with a regular video camera is interlaced in nature, as well as is a good part of tv productions.

Update #3: Several "making SVCDs" type tutorials added into the related links section.

I'm still interested in any comments and hints from those of you that have experimented with making your own SVCDs.

5.1 Overview

SVCD is based on regular CD media. Thus, it is technically possible to burn SVCDs all by yourself with a standard CD-R writer.

Some obvious applications for home-burnt SVCDs include

In order to create SVCDs, you need:
Note: Some people have been experimenting with non-standard deviations of both VCD 2.0 and DVD formats, often respectively called XVCD and MiniDVD (of which the latter one seems to be largely mythical, since I have not yet seen reports on any stand-alone DVD player being actually capable of playing those). Despite very convincing-sounding names, these are not standards at all - not even coherent technical specifications - but just some very loosely coined general terms for discs that have specifically been altered not to follow the standards.
Do not confuse XVCD or MiniDVD with SVCD. SVCD is an industry-backed standard. Properly made SVCD discs are guaranteed to work in any SVCD-compatible player. The aforementioned deviations do not come with such guarantees. It is up to you: if you really want to trust your precious video on a non-standard format that may or may not be readable in the future on a different player, go ahead. I would rather not.

5.2 About SVCD authoring packages

5.2.1 Why do I need one?

SVCDs are not like your regular CD-ROMs. You cannot just burn some MPEG-2 files on a blank CD-R and expect the end result to pass as an SVCD disc. The SVCD specification requires using a specific CD-XA sector format and a strictly defined directory hierachy, complete with MPEG tracks and some special control files.

It would be extremely difficult (if not outright impossible) to hand-craft a proper SVCD disc in a regular CD-ROM authoring application. If one failed to follow even a slighest detail in the specification, the disc would not play properly on a standard SVCD player, and could not be considered an SVCD disc at all. This is why SVCD discs are always created using specialized SVCD authoring software.

A proper SVCD authoring package contains all the necessary tools and editors for managing the video clips and defining multi-level menus, subtitles, still images, slide shows, playlists and other navigational elements needed for accessing all the content that has been prepared for the disc. In the end of the day, the authoring package is used to create the necessary binary image file which one can then burn on a blank CD-R disc.

5.2.2 Where do I get one?

Up until these days, the most irritating problem with the SVCD format has been the lack of consumer-level authoring tools. There have not been many available in the first place, and almost invariably they have been aimed at professional users only. As you might have guessed, this kind of software often tends to bear a "professional" price tag as well. (You will find four such packages at the related links section below.)

Fortunately, the situation is now starting to look better from the consumer viewpoint: The forerunner in this sense has been Ahead Software which has recently released an SVCD-capable version of their Nero - Burning Rom CD authoring software.

As for the technical issues, SVCD is basically nothing more than just an extended VCD 2.0 specification. Although it is not a direct superset, it is still close enough to be considered as a cousin format. As the technical similarities are obvious, it is conceivable that the currently available VCD 2.0 authoring tools will evolve into SVCD-capable authoring tools over the time. Hopefully this will happen sooner rather than later so that we can get some real competition on the field.

Basically it's up to you: let the manufacturers hear what you want. If you want it to happen sooner, you should kindly request the SVCD capability in the future versions of Adaptec'sEasy CD Creator and other CD-ROM authoring packages.

6. Related links

6.1 General information about the SVCD standard

The Super Video CD FAQ contains complementary information, and goes hand in hand with this overview. Read it before e-mailing me questions. I would also suggest following the discussions in the rec.video.desktop, comp.ivideodisc, comp.publish.cdrom.multimedia, comp.publish.cdrom and alt.cd-rom newsgroups.

6.2 SVCD authoring tutorials

6.3 SVCD authoring software

6.4 SVCD test disc images

6.5 Software-based (possibly SVCD-compatible) MPEG-2 encoders

Note: SVCD specification requires that every intra frame in the video stream is accompanied by a special block called "User Data". This block apparently contains scan and closed caption information. Missing or empty "User Data" blocks will probably at least affect the seek capability of the player. Moreover, an SVCD disc that does not contain "User Data" blocks is probably invalid from the standard's viewpoint.
 
Supposedly, there are two possible mechanisms for inserting the "User Data" blocks in the elementary video stream:
  1. The MPEG-2 encoder can specifically allocate empty space for the "User Data" blocks in the elementary video stream. The SVCD multiplexer is then supposed to fill the actual data in those blocks. (This is probably how bbMPEG's SVCD encoding works, although I'm not sure.)
  2. Another theoretically possible scenario is that the MPEG-2 encoder does not specifically create any empty space, but the SVCD multiplexer is still flexible enough to insert the "User Data" blocks in the stream. (I do not know if there are such multiplexers.)
It is almost certain that no MPEG-2 encoder will automatically create any space for "User Data" blocks in the stream. So either the SVCD support must be built-in (as is the case with bbMPEG), or the encoder must be tweakable enough to allow creating a profile that takes this issue in consideration. On the other hand, if an SVCD multiplexer requires that there are empty spaces for inserting the block data, this would mean that you could only use SVCD compatible encoders with them.

As of now, I am not greatly confident about any other tools supporting this correctly than bbMPEG and Philips SVCD Designer/Toolset. There may very well be tools that claim support for SVCD, but whose author has not even heard about "User Data" blocks. I am also not too sure if even Philips' own multiplexer can properly handle any elementary video streams - or just those that have the empty placeholders for "User Data" blocks. Somebody obviously needs to test and analyse this more.

If you have any concerns about the encoders, multiplexers and authoring tools you currently use, you should contact the company/individual who makes the product and ask them about it. After all, this is one of the best ways to make the situation better. If you would happen to get any useful information on the subject, mail me. I would be glad to add the info on this page.

The main problem seems to be that it is unknown on whose responsibility it actually is to insert and fill in those blocks. Is it the encoder? Or the multiplexer? Or both? Should the authoring application be somehow involved?

And what if you use an SVCD authoring program that does not come with its own multiplexer? Does that kind of authoring tool even check that your stream is within the specification's limits? Does it warn you if there are no "User Data" blocks in place, or if they have not been properly filled with the required information?

So many questions, so few answers... :(

6.6 General video tools and information

6.7 Software-based MPEG-2/SVCD players

6.8 Hardware-based MPEG-2 decoder/encoder solutions

6.9 Companies that sell or manufacture SVCD-compatible stand-alone video disc recorders

6.10 Companies that sell or manufacture SVCD-compatible stand-alone VCD/DVD/MP3 players


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