CD-i FAQ 2000 Edition
Section 6. Video-CD on CD-i
6.1 What's the difference between a Video-CD and a Digital Video on CD-i disc?
In conjuction with the introduction of the Digital Video cartridge for CD-i players in 1993, Philips published some movies on CD that can be played on a CD-i player equiped with such a cartridge. Although the Video-CD specification already existed at that time, for some marketing-political reasons the movies were released in CD-i format instead of Video-CD. This means that the discs can only be played on CD-i players and not on Video-CD compliant players like Video-CD players, game consoles and most DVD-Video players.
Although the discs looked very similar to 'normal' Video-CDs, Philips used several techniques to make them distinguish from Video-CDs: the physical sector locations of the video-files differs from Video-CD and the used file system is CD-i's propietary format instead of ISO-9660 which is required for CD-i Bridge format discs like Video-CD. As a result, both playback devices that look for the MPEG-files to play them (such as PCs) and playback devices that are based on simple microcontroller circuits that start playback of video at a defined sector location (like Video-CD players and DVD-Video players) cannot play the discs.
Furthermore, the resolution of the MPEG video on a CD-i movie disc is slightly higher than the defined resolution of a Video-CD disc (384x288 instead of 352x288). This also prevents people from extracting the video from a CD-i disc and then immediately use it to burn a Video-CD. To do this, one needs to re-encode the video according to the White Book (Video-CD)specifications. Of course re-encoding MPEG material will greatly decrease picture quality.
To identify the format in which a movie is published, look at the text in the lower left corner at the front of the disc's inlay. When it says Digital Video on CD-i, it is in CD-i format. When it says Video-CD, it is in Video-CD format. Please beware not to look at the text printed on the plastic of the case itself. Some true Video-CDs contained the text 'CD-i' on the case. The correct format however is always clearly indicated on the inlay. Some 20 or so movies were published in the Digital Video on CD-i format, of which most were re-released in Video-CD format some time later.
Some Asian Video-CD players were able to run some of the Digital Video on CD-i discs as if they were Video-CDs. Please note that these players only play some of the titles indicated as Digital Video on CD-i, but not regular CD-i discs (nor the MPEG video sequences contained on it) which are usually indicated as CD-i Digital Video.
To bypass the file format problem on Windows 95/98 based PCs, a solution was made available in late 1999 with the release of the CD-i Filesystem Driver. When this driver is installed, you can access a CD-i disc in a similar way as a CD-ROM, and you will be able to play MPEG sequences that are stored on it. The CD-i Filesystem Driver is available for free download at the PC downloads for CD-i development page at this site. For more information about using the driver, please refer to section 9 of this FAQ: CD-i on other platforms.
6.2 What are the differences between the various Video-CD versions?
Several versions of the Video-CD specification (described in the White Book) exist. All of the versions are interchangable as far as the video sequences are concerned (e.g. the video on any Video-CD can be played on any Video-CD player regardless of its version), but some discs may contain features that are described in a higher version which are only accessible on a player that supports this higher version of the standard. The following versions of Video-CD exist today:
The first version of Video-CD was still called Karaoke-CD. It was set up by Philips and JVC in 1992 to be used mainly in Japanese karaoke-applications. Only the basic video features (like the division of various songs into tracks) were specified in this version.
The system was renamed into Video-CD in 1993 to show the broader range of applications in which it could be used. The system is now defined by Sony and Matsushita as well. Some features were added, like the sub-division of a track (an MPEG video sequence) into chapters. This allowed for the playback of continuous video while still providing the possibility to jump directly to a specific chapter.
With Video-CD 2.0, introduced in 1994 by all of the original Video-CD 1.1 companies, some very neat features were added, like limited interactivity in the form of menu screens with selection items (comparable to DVD-Video), the use of high resolution MPEG-still images, the possibility of slide shows with or without audio and the possible inclusion of CD-Audio tracks on the disc.
Please refer to What version of the CD-i application should be used for the different Video-CD versions? for more information about the use of the CD-i application with respect to the various versions of the Video-CD specification.
6.3 What CD-i applications for Video-CD were available?
To allow playback of a Video-CD title on a CD-i player, every Video-CD disc must include a CD-i application. This is a mandatory requirement in all versions of the Video-CD specification. Several of such applications existed, the most important of them were:
This software from Philips is probably the best-known CD-i application for Video-CDs. Sometimes it is code-named 'Franklin'. It is used on most (non-American) Video-CDs, and it is bundled with various CD-Recording tools (like Ahead Nero and Adaptec Easy CD Creator). It allows for extensive customization, but it can also be used 'as-is', since it completely adapts itself to the disc's contents. Several versions of this application exist, which are described in more detail in What are the differences between the various versions of Video-CD on CD-i? below.
Edison, developed by Philips Interactive Media of America, was mostly used on American-released Video-CD discs from Philips. The application needs to be adapted by the content developer of a particular Video-CD title to work on a CD-i player, and as such it required extra work to make a Video-CD CD-i compatible. You can recognize the Edison application from its volume option which displays a green indicator on screen.
OmniMedia from the UK developed their own Video-CD application, which was used on Video-CD discs from Castle Multimedia and EMI Records, among others. As with Edison, it needs to be completely adapted to get it to work on a particular Video-CD title.
The CD-i application that is bundled with recent versions of CeQuadrat's CD-Recording tools like WinOnCD 3.6 has been developed by CeQuadrat itself. It does not need to be customized since it dynamically adapts itself to the content of a disc, but it looks rather dull and offers only very limited features (like advancing to the next track). It is expected that future CeQuadrat/Roxio tools (like VideoPack) include an option to replace the bundled CD-i application with the Philips application that can be downloaded from www.icdia.org.
6.3.1 What are the differences between the various versions of Video-CD on CD-i?
As stated above, the most widely used CD-i application for Video-CD discs is Video-CD on CD-i. Of this application several version exist. The version number of the application will be shown on screen when the application exits. The most important are:
The first version was especially made for Karaoke-CD. It starts with a short animation displaying the text 'Karaoke-CD'. It adapts itself to the disc's contents, showing the name of the disc and selection boxes with numbers according to the available tracks. The application can be adapted in some limited ways, by replacing the background image from the menu screen, or by replacing the number boxes with boxes with the song's title in it.
The program was changed to allow for other applications besides music video or karaoke. The layout of the buttons was changed from the colorfull yellow and red to more quiet shades of gray. Some terminology was changed (like the "Vocals on/off" switch in the settings screen which is now called "Channel 1/2").
Complete restyle of the layout of the application, that has been used troughout all 3.x versions. The application now fully supports Video-CD 1.1, for example it allows advancing to chapter points within a track. Display of track number, chapter number and running time using 'on screen display'. It had some new playback features, like displaying succesive stills when the pause button is pressed repeatingly. The application can be customized in extensive ways, for example by replacing the background of the menu, by implementing hot-spots within menu screens that advance to video sequences or other menu screens. Minor things like the color of the cursor, the time-out time for the video to begin, and wether or not the introduction sequence should be interruptable could also be defined by the content developer.
This version continues the display time on the next disc in a multi-volume disc set, instead of beginning all over again. It allows for CD-i specific subtitling. Scan (search) functions can be enabled or disabled.
Search-function now continues when the button is pressed for a given amount of time. 7-speed slow motion function added. Improved the font of CD-i closed captioning. Support for CD-i multi disc titles: the application request the next disc without going trough a player reset.
Channel selection can be included in the menu screens by content developers (compare to audio selection on a DVD-Video disc). Some minor changes and improvements.
Slighty optimized version, minor performance improvements and error correction enhancements.
This version of the application fully conforms to the Video-CD 2.0 standard. Customization of menu screens now conforms to the White Book 2.0 standard (background images, menu selections, etc.). Support for the display of high resolution MPEG still images. Support for the playback of CD-Audio tracks on a Video-CD disc. CD-i specific subtitling is still available. CD-i specific customization of background screens and menus as used in the 3.x application has been removed.
This version continued the support of the Video-CD 2.0 standard. It now includes support of extended PSD, allowing for hot spot selections in screen images like with the 3.x application (but now in a Video-CD 2.0 consistent manner), instead of only allowing for number selection in the menu bar.
Some interim-releases for the 4.1 version are also available (4.1.1 up to 4.1.7). Minor bugs were fixed and the automatic recovery of video playback in case of a read error was added which is usefull in environments where user control is not available (such as with linear in-store video display).
Both the latest Video-CD 1.1 optimized version (3.2) as well as the latest Video-CD 2.0 compliant version (4.1.1) are available for download at the CD-i Application Downloads section on this site.
A document intented for Video-CD producers describing how to install and customize the Video-CD on CD-i application version 4.1 can be found in the CD-i Technical Documentation / Software section on this site.
6.3.2 What version of the CD-i application should be used for the different Video-CD versions?
When you make a Video-CD, make sure it contains at least version 3.0 of the Video-CD on CD-i application, since the preceeding versions do not adapt themselves to the disc's contents. They need to be customized at program level to work on a particular disc. Beginning with version 3.0, when the application is placed on a Video-CD without any customization, it looks for the disc's contents (tracks, chapters, the disc's name, etc.) and presents a menu accordingly.
Version 3.x of the application is especially designed for Video-CD 1.1, it recognizes the tracks and the chapter numbers. Version 4.x is especially designed for Video-CD 2.0, this version displays Video-CD menu structures, stills, etc. When you make a Video-CD 2.0 disc which includes special 2.0 features (like the menu's and stills), and you want to be able to use them on a CD-i player, you must use at least version 4.0 of the application. When you place a 3.x application on a Video-CD 2.0 disc, you will still be able to access tracks and chapters, but you won't see menu screens. This is because the menus in a 3.x application need to be made especially for CD-i, and this is not taken care of by any Video-CD creation tool to date. On the other hand, when you place a 4.x application on a Video-CD 1.1 disc, or on a Video-CD 2.0 disc without any menu screens or stills, you will see the standard version of the application, adapted to the discs contents.
To conlude: you can exchange both 3.x and 4.x applications on both 1.1 and 2.0 Video-CD discs, but in order to use Video-CD 2.0 enhanced features on a CD-i player, the disc must include a 4.x application. If you make a Video-CD 1.1 disc, or a Video-CD 2.0 disc without the special 2.0 features, and if you have the choice, use the 3.x application. The 3.x application is more stable and generally has a better look than the 4.x application.
Please note: some CD-R tools with Video-CD creation functionality include a version of Video-CD on CD-i that is not adapted to the Video-CD version that is created. For example: Adaptec Easy CD Creator 4 creates Video-CD 2.0 discs with menus but includes a 3.x application. As explained above this works fine, but special conditions apply.
6.3.3 How can I customize the Video-CD on CD-i 3.x application?
Version 3.x of the Video-CD on CD-i application can be extensively customized for display exclusively on CD-i players. This allows for the replacement of the default background image, for the creation of menus with hotspots which direct to other menus or video sequences and for the adjustment of all kinds of settings of the application.
Most Video-CD creation tools do not allow you to make these CD-i specific adaptations. Especially when menu-screens are concerned, this involves heavy knowledge of the format of the image files and menu screens. The way on how to make these screens and menus is defined in the Product Information and Installation Notes manual that is provided with the application when you buy a license from Philips. Contact your CD-R software vendor for a copy when the application was provided with your CD-R creation tool.
Besides the menu screens, there is also a general configuration file called CDI_VCD.CFG which is placed in the /CDI directory on the Video-CD. It is a simple ASCII text file that is being read by the application at startup, which then adapt itself to the given configuration. It contains settings to change the color of the cursor, the type of background replacement, wether the menu bar should be able to be recalled, the timecode to start with on a second disc, the initial track number (on a second disc in a multi disc set), the initial subtitle language and color, the bumper interruption time, the time out value and wether the scan options should be available. The last one might be important, please refer to Why can't I fast forward or reverse with some discs? hereafter.
6.3.4 Where can I get a CD-i application to use with my Video-CD creation tool?
If your Video-CD creation tool does not include a CD-i application by default, or if you want to replace the bundled CD-i application with another more sophisticated version, you can download the official Philips Video-CD on CD-i version 3.2 and 4.1.1 releases from the CD-i Application Downloads page. Refer to What version of the CD-i application should be used for the different Video-CD versions? to decide on what version to use.
If you are using the freeware VCDimager (source code and builds for various operating systems are available), you may use the 4.1.1 application to create Video-CD 2.0 discs that are fully CD-i compatible. Have a look at the documentation that comes with VCDimager for more info on how to include the application on the disc, and how to set the application as the startup program for CD-i players. You may also use VCDimager Easy, a GUI to VCDimager for Windows, which includes the CD-i application by default.
If you want to replace the CeQuadrat CD-i application bundled with WinOnCD and VideoPack with one of these applications, special provisions need to be made. We will include an article on how to do this on this site soon.
6.4 I have a Video-CD. Why won't it play on my CD-i?
It is known that several so-called Video-CDs exist that do not play on a CD-i player. This is mainly the case with certain titles from China and the Far East. Mostly, this is due to the absence of a CD-i application on the disc. As mentioned before, such a CD-i application is a mandatory requirement for a Video-CD, and a disc that does not include it violates the license terms (but this is often the case with illegal discs for which no license fees were payed in the first place!). When no 'Play CD-I' button appears when you load the disc in a CD-i player, or when it does appear but the player resets moments after you selected this button, you can be fairly sure that this is the reason the disc won't play. It has nothing to do with CD-i being unable to play some Video-CD discs (2.0) as is sometimes incorrectly stated in newsgroups among others.
If the application does show up, but the video freezes immediately or after a few minutes, then your MPEG is probably out of spec. Refer to Why does the video on my home made Video-CD freeze?
6.4.1 Why does the video on my home made Video-CD freeze?
When a disc does include an application and it shows the track numbers, but it won't play the video sequence when you select it or it will 'hang up' the player after a few minutes, this is probably due to the fact that the MPEG video on the disc is not according to the Video-CD specification. It is extensively specified in the White Book how the video and audio should be encoded on a Video-CD. When the video is in a different format it might still play on a PC with a very tolerant video playback application, but a CD-i player (and the Video-CD playback application) is very picky about the MPEG stream being according to the White Book Video-CD specification. Being unable to play this MPEG has nothing to do with the CD-i application being 3.x or 4.x, as is sometimes incorrectly stated.
If you suffer from this problem, try using another MPEG encoder that is capable of producing White Book or Video-CD compliant MPEG streams. Use an encoder with pre-defined settings for creating a Video-CD compliant stream, since trying to set the values yourself will not work in most cases. The Panasonic MPEG encoder is known to produce incompatible streams. One encoder that is known to produce fully White Book compatible MPEG is the free program bbMPEG, available from the bbMPEG homepage. You may also use the internal MPEG-1 encoder of Nero Burning ROM when you make a Video-CD with this program.
6.5 Why can't I fast forward or reverse with some discs?
To enhance the performance of the scan forward and backward (search) functions in the 3.x versions of Video-CD on CD-i, Philips defined a file format for entry point lists. Such a file contains the absolute address numbers of sectors that contain MPEG I-frames that are needed to display an image when performing a search. For each of the MPEG-files on the disc, an ASCII-file similar called to the MPEG-files (such as AVSEQ01.DAT) should be placed in the /CDI directory. When such files are not present, the application disables the search functions by default.
Since such entry point files are CD-i specific, Video-CD creation software usually does not generate those files. When you still want to be able to use the scan function without putting the entry points on the disc, you should add the line SCAN=ALWAYS to the CDI_VCD.CFG file in the /CDI directory. It is extremely important in this case that the MPEG stream is 100% in accordance to the White Book specification. If MPEG I-frames are more than 2 two seconds apart from each other (which is not allowed by the White Book), searching will result in a hang-up of the application.
Beware: with most CD-Recording tools it is either impossible to add files to the /CDI directory, or to modify the supplied CDI_VCD.CFG file.
Note: this info is only applicable to version 3.x of the CD-i application, not the 4.x (Video-CD 2.0) application. This version should be able to provide scanning without an entrypoint file, provided that the MPEG stream is 100% according to the White Book standard.
6.6 What is Video-CD 3.0?
Video-CD 3.0 does officially not exist. The only versions of the Video-CD specification released to date by the official Video-CD creators Philips, Sony, JVC and Matsushita are 1.0, 1.1 and 2.0. Some Chinese Video-CD players claim compatibility with Video-CD 3.0. It is unclear what they refer to, or wether all so-called Video-CD 3.0 players refer to the same system. They should at least be able to play 'real' Video-CDs.
6.7 What is CVD or Chao-Ji?
CVD and Chao-Ji are two of the extensions to Video-CD that were developed in China. Both systems use MPEG2 to encode video and hence the discs are not compatible with Video-CD or CD-i players. Both systems are also not interchangable with each other. In order to accomplish for a worldwide standard for MPEG-2 on CD, the original Video-CD companies created Super Video-CD. A true Super Video-CD can however be played on both CVD and Chao-Ji players, since it uses subsets of both systems. Refer to What is Super Video-CD? for more information.
6.8 What is Super Video-CD
Super Video-CD is an extension to the Video-CD specification, set up by the original Video-CD licensees (Philips, Sony, JVC and Matsushita) in 1999. Super Video-CD uses DVD-quality MPEG-2 video on a standard CD which runs at variable bit rates up to double speed (2.8 kbps). This allows for 35 to 70 minutes of high quality video on a regular CD. Super Video-CD allows for a cheap way of making discs that are playable on compatible DVD-Video players using a regular CD-Recorder.
Since Super Video-CD uses MPEG-2 video compression instead of MPEG-1 that is used in CD-i, and because of the fact that the disc can be played up to double speed of which a CD-i player is not capable, a Super Video-CD cannot be played on a CD-i player. Therefore, the CD-i application that is mandatory for Video-CD is not available on a Super Video-CD.
A very nice website with more information about Super Video-CD (among others) can be found at www.iki.fi/znark/video/svcd/overview.