JPH04170766A - Device and method of coding at least two pair of data in sub-code channel of compact disk or laser disk - Google Patents

Abstract

PURPOSE: To provide a device for encoding graphic data by using a sub-code channel of the digitized sound data of an audio compact disk or the sound data of a laser vision disk. CONSTITUTION: When a program 21 is started, it is loaded in a memory by initialization 43, and two screens are presented to artist/operator. One screen displays a menu 45 specifying operation supported by the selective program. They are a 47 adding a characteristic, an editing/deletion/moving characteristics 49, keeping/loading order information 51, conversion to a sub-code format 15, a data transfer 53, reproduction 55 and end 57. The data transfer block 53 reads an order table, and takes the sub-code data in a file, and transfer them to a decided correct place at a specified offset, and distributes the data according to band division information in a header in the characteristic file 49.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention is directed to the use of what are known as subcode channels of digitized audio data of audio compact discs or laser vision disc audio data. The present invention relates to an apparatus and method for encoding graphical data onto a compact disc or laser disc without affecting the digitized audio stored in the main audio channel. In particular, an apparatus and method for forming multiple active areas on each screen or each displayed image is disclosed.

Although this technique is described for the subcode channel of an audio compact disc, it is equally applicable to laser vision discs as will be apparent to those skilled in the art.

[Conventional technology]

Currently, audio compact discs use 9596 of their capacity to store digitized audio, with the remaining 5% reserved for what are called subcode channels or areas. Approximately 3 if all are used
A subcode channel corresponding to a data capacity of 0 megabytes is used for graphic information or FiMIDI information. (An apparatus and method for encoding MIDI data into subcode channels is described in pending U.S. Patent Application No. 211,355, filed June 24, 1988.) Graphical Subcode Data , the compact disc player must include a graphic decoder to decode the graphic subcode data.

Because of limited bandwidth, the subcode channel graphics are not full moving videos. In fact, subcode graphics are static images and static text that can change gradually over a period of seconds. Each graphic [screen (which can be composed of photographs, illustrations, and text) is created from only 16 colors, rather than the myriad colors available for film and video images. Choose 16 colors from 4096 colors for each screen! It may happen (1
6 shades of gray can be replaced by a spectrum of 16 colors). But only 16 colors of gold are available at a time.

For this reason, subcode channel graphics cannot compete with images of movies or video clips. Rather, such graphics enhance the sound on a compact disc, such as emphasizing information about the recording when played back.

An example of the use of subcode channel shapes is as follows.

1) As the lyric is recited, write the lyric on the television screen, exactly like the lyric written on the album cover.

it) Translating a lyric into a language other than the language in which it is recited.

iii) Explain what is happening in the music (
soloists, timing, countermelody, and spatial arrangement of instruments).

IV) Provide context to the listener.

■) Create a narrative or abstract visual accompaniment to the music.

vl) Images of artist or fan magazine information.

vll) Add subtitles to movies by matching graphics to live video off a laser disc.

〔Example〕

Audio compact discs, by industry standards, exclude a large portion of the data storage capacity possible for non-compact disc audio. In other words, 95% of the possible data storage capacity for storing digitized audio recordings.
% is used. The reserved 5% portion, known as the subcode, actually stores purely numerical data in an industry standard format. In particular, the data in the subcode channel is stored in a set of 24 words. Each word is the first
8% SlT% U, respectively as shown in the figure.
It consists of 6 bits marked as V%W. Each bit within a subcode channel is one of six subcode channels. Details about acid data files on compact discs can be found at Philips
s) Compact Disc Digital Audio System Description (Co
mpact Di Hatake CD1g1tal Audio S
The following is contained in a document known as the "Red Book", which is a technical specification entitled "Acid channels R, S, T, U, V, W (Sub C
hannels 8% 8% T% 0% V% W
) is found in the section entitled J.

FIG. 1 shows one back of subcode data. There are a total of 24 6-bit words in the back, but the "red book"
According to the specifications, only 16 words of the puncture and 2 words of header information (command, mode, and item) are available for data at a rate of 300 packs per second. In other words, for every second of audio on the main channel of a compact disc, up to 300 backs of graphical subcode data are available to form a graphical image on a television display. The time required to display a particular shape is a function of the number of graphics instructions required to describe the shape.

To explain this, the full screen of figure information is 1
The row has a width of 288 pixels and a height of 192 pixels.

However, graphic subcode data can only be used in units called fonts. The valley font is 6 pixels wide and 12 pixels wide.
It is the pixel height. Therefore, the information for the entire screen is 48 fonts wide and 16 fonts high, for a total of 768 fonts per screen. Each font can contain from 1 to 16 colors.

The time required to display a shape is a function of the number of instructions required to describe the shape. In this regard, the simplest graphics (one or two colors) require 91 instructions per font, so 9768 fonts per entire screen. According to the "Red Book" specifications, each graphic command requires subcode backs at 300 punctures per second, so a simple full-screen graphic takes about 2.5 seconds to display. Similarly, a full screen graphic containing 16 colors takes almost 10.25 seconds to display. In other words, 768 fonts per screen and 4 instructions are required to describe 7 fonts of 16 colors, so 3072 instructions are required for full screen display. Therefore, the available 768
Which of the fonts to write, its content, and its color are specified in the graphic command.

In a typical application using the subcode channel, for example, lyrics may be displayed one line at a time as a song is sung, and graphical instructions may only require updating 48 fonts per line. This update can be performed in less than 0.20 seconds. However, it is often desirable to display one line of lyrics in two or more languages. Related to this, if you want to display a lyric poem in two languages, the first
It is necessary to display a one-line lyric poem in a language in a second language in a display box for a one-line lyric poem in a second language. The reason is that the rounding that describes the first line requires 48 subcode packs,
This is because 48 subcode punctures that occur later are required to describe the second line. In this example, only one of the two lines can be synchronized because the second line cannot be displayed until after the first line is displayed.

The present invention provides a method and apparatus that allows for the display of multiple activity areas so that multiple activities appear to be occurring simultaneously. so that some of the 300 instructions available each second are dedicated to one activity area, and the remaining instructions are dedicated to one or more other activity areas.
The present invention does this by dividing the graphical instructions into bands. Bandwidth partitioning is basically a shortened expression for ``dividing the bandwidth,'' which is used to use every other data area in a subcode pack for various purposes. be. A band is data dedicated to changing a given portion of a video display. In the preferred embodiment, half of the instructions, 150 out of every 300 pack, are dedicated to loading an image band called band rAJ, and the remaining instructions are assigned to bands B%C%D, It is evenly divided between five lyric bands called E, F. Each lyric band takes only 1096 or 30 commands per second.

Of course, the bandwidth can be divided into different numbers of 90,000, and more or less bandwidth than 6 can be used.

Using this technique, the time required to display a complete screen increases. That is, if an A-band using 150 out of 300 instructions per second were used to load the entire screen, it would take twice as long as if all 300 instructions were used. but,
When using the band division technique of the present invention, the size of the active area is made proportional to the dead time length allocated to the band for graphical commands. Therefore, the A band must typically fill no more than half the screen.

In another example, for 16 colors of ij'FII, lO
K to load the entire screen using 102
．． It takes 4 seconds. It is for this reason that the KIO-band is commonly used to load lyrics. The active area for lyrics can be a single font height. The active area extends across all 48 fonts spanning one line of the screen. Depending on the rounding and style of the text, text characters can fit an average of only 35 to 40 characters across the 48 font width of the screen, so the entire 48 font width can be easily readable. width. At 30 fonts per second, this area will load in 1.6 seconds.

For most songs, a lyric line that takes the 35-40 characters available takes 1.6 seconds or longer to sing. It can exceed the speed of 35 to 40 characters of long lyric poems recited in 1.6 seconds. However, in those cases two bands can be used so that two lyric lines of 35-40 characters can be loaded every 1.6 seconds.

To explain, the first image that is displayed when the music stored on the compact disc starts is the 7 ont win!
:If the J4 instruction occupies the upper half of the screen, or 384 fonts, and uses 16 colors, then 1536
instructions, or 1536 subcode packs. At 300 packs per second, this image would take 5.12 seconds to display without band splitting, or 10.24 seconds if using the A band.

If the first lyric line is also to be displayed when the music stored on the compact disc begins, its 48 font width information requires 48 punctures.

The use of no more than six bands is preferred for the following reasons.

In the United States, each video frame is 1/3
The television receives a video signal according to the NTSC standard, which specifies 0 seconds.

The NTSC standard has 92 video frames per screen. As mentioned above, there are 300 subcode data punctures per second, or 10 packs per NTSC7 frame. Thus, an NTSC frame can contain graphical information corresponding to 10 subcode packs. Allowing one subcode pack for each of the 10 bands per NTSC frame allows for It can display a 10 line lyric fast enough, but there is no space for images of any kind.

Reference is now made to the fa2 diagram where the data layout for using six bands is shown. In this case half of the packs are assigned to band A and one out of every ten punctures is assigned to bands BF. Similarly, the third
The figure shows a layout in which only bands A and B have graphical information to be displayed.

FIG. 4 illustrates in block diagram form the steps necessary to manufacture a compact disc in which graphical data is organized into bands in accordance with the present invention.

Is block 11 digitized 16-color graphic data? Represents a containing file. Each image to be converted to subcode is in a separate file. This graphical data is created using techniques well known to those skilled in the art, such as taking an NTSC tape or camera footage and digitizing it to 16 bits to create a digitized file representing the image. AT&T Targ that forms the image
a) Construct a digitized file representing an image using 16 boards. The digitized image is then displayed on a color monitor and a digitized image with no more than 16 colors is created by the artist/operator so that the image can be converted to a subcode format that allows only 16 colors per image. transformed by the artist/operator into an image.

Although these files do not contain time information, typically the person manufacturing the files used to press the compact disc knows the offset from the start of the compact disc audio.

Similarly, block 13 represents a file containing digitized lyric data. Each line of the lyric to be converted to subcode format is in a separate file. This lyric data is created using techniques well known to those skilled in the art, typically involving creating an ASCII file of the lyric in a word processor, and then converting the ASCII text to a graphic file using the desired character style. do. A separate file is created for each lyric line, and there is an l:1 correspondence between lyric lines in each language to be displayed. For example, if the lyric of a song is to be displayed in English and Italian, for every line in English there is a line in Italian.

Blocks 11 and 13 therefore contain several files of digitized graphical data.

In this case, there is one file for each image and one file for each lyric line.

Once the 16-color digitized paintings and lyric files have been created, the data in those files must be converted to a subcode format. This is a computer subprogram that reads the digitized graphical files represented by blocks 11 and 13 to create files in subcode format, i.e. the subcode paracles with the graphical instructions defined by the Red Book. 15, so that there is one file for each image and one file for each lyric line. The file begins with header information that specifies the band in which the data should be placed. Since the digitized graphic data of block 11 and the digitized lyric data of block 13 are files containing graphic information, in order to read these files and convert them into subcode format, One program is available.

The functions carried out by the program in block 15 will now be described with reference to FIG.

1. Another input to block 15 is information in layout file 19. The information describes the allocation of subcodebacks to each band within each video frame. A layout file is created when a disk trunk is designed and contains the following information:

(,) Which nodes in each file are dedicated to each band.

(b) Which fonts on the video screen are updated by each band.

O) Which graphics channel is each band dedicated to?

To explain these subcode files, assume that a particular song has 100 lyric lines and that we want to display the lyric in two languages: English and Italian. Therefore, there are 200 files representing lyric poems. Assuming that each lyric line fits on one 48 font wide screen display, each file has 48 subcodes. Also, assuming there are 20 images, each image has 3840 fonts with 16 different colors, for a total of 1536 subcodebacks. Therefore, there are a total of 220 files as shown in FIG. 5, each file consisting of subcode backs for the corresponding lyric line or image.

Although the subcode back or file created by the subprogram of block 15 can be used to press a compact disc with subcode information, the decoder within the compact disc player will not know when to display the data in the subcode back. It simply displays the data in the same order as the subcodebacks, with no way of knowing the order.

If arranged as shown in Figure 5, the first lyric lines 1-100 in English will be displayed, then the lyric lines 1-100 in Italian will be displayed, and then the image will be displayed. Is displayed. This of course makes it impossible to synchronize the graphical display with the main channel audio.

Therefore, according to the present invention, after the subcode back file is created by the subprogram of block 15, the main file containing the subprogram of block 15 and shown as block 21 in FIG. A second program, which can be the remainder of the program, arranges the subcode backs in one large ordered file as described below.

The computer program in block 21 must create a file. In this case, the 220
The subchord punctures of each record within the lyric and image files are ordered. To be precise, ordering the lyrics requires knowing the offset from the beginning of the main channel. This information is easily obtained by utilizing the SMPTE time code. That SMP
The correct offset for each lyric line can be determined from the TE time code.

Once the correct offset information is obtained, as the program 21 reads each lyric line, it prompts the operator to enter the correct time offset for that line, as indicated by block 11. Similarly, for each image, the operator is required to enter the correct offset f for that image as the program 21 reads each image file. Therefore, assuming that the SMPTE time code for lyric 1 is 00:00:01 and that the start of image 1 is displayed at the beginning of the lyric, the operator would
Enter 00:00:01 for Italian lyric line 1, and enter 00:00:01 for mel.

The information in the layout file 19 is compared to the bandwidth allocation table that is part of the header record of each feature file, as described below. This operation continues until each file containing subcode data has been associated with a main channel audio offset.

Using this offset information, the program 21 creates one ordered file as follows.

Assuming that band A is a 50-wire band, the file for image 1 is read and every other record in the output file is
It is left blank as shown in FIG. It shows the first 20 records of the ordered file. The operation is then repeated for each remaining image file, ie, image files 2-20 in the above example, and the starting record for each image file is determined by the offset for that image. For example, picture g12 is 2
3 per second, assuming an offset of 0 seconds
Since there is a 00 puncture, image 2 must start at record 6000 in the ordered file.

Similarly, English lyric poems are written in a 10-chi band, band BKf, and Italian lyric poems are written in another 10-chi band, band CKf.
When placed and created, the @1 subcode pack for English lyric 1 is placed in record 2 in the ordered file, and each subsequent subcode pack Ifi for English lyric is placed in record 2 in the ordered file.
Offset by 10 seconds, the first subcode pack for Italian lyric 1 is recorded in the ordered file 3
placed in Each subsequent subcode pack of the Italian lyric is offset by 10 seconds as shown in factor 7.

The ordered subcode pack of FIG. 7 is a file that can be used to manufacture a compact disc with subcode data as shown in block 23. The method of processing compact discs can be performed by anyone who has obtained the necessary permissions from Sony or Phillips N, V.

When a compact disc is played using a graphical decoder, the first screen displayed, i.e. the first 1/2
The 15 seconds are based on the subcode packs shown in FIG. 7, namely the first 10 packs of picture*i, packs 1 and 2 of the English lyric, and packs 1 and 2 of the Italian lyric. Subsequent screens display 5 images 10 next packs 10 until all information in the subcode puncture is displayed.
and displays the following two punk poems, an English lyric poem and an Italian lyric poem.

FIG. 8 is a diagram showing the functions performed by subprogram 15. The initialization and access layout parameters block 31 determines where the shape will be placed on the display, how the subcode transformations will be performed, such as the dimensions of the part of the shape to be transformed, and what fonts will be used. or read parameters describing band matching, etc.

A load graphics or lyric data block 33 is used to access the raw graphics data generated by blocks 11 or 13, such as the AT&T Targa.
a) 16 boards), store the graphical data or lyrical data in a memory or disk file called a microfile in order to convert it into a subcode pack.

The feature file contains data in subcode format and the following information for the first 48 pieces of hander data.

(1) 4 bytes specifying the number of punctures over which the data is spread.

(2) Bandwidth allocation table that describes which punctures in the file are dedicated to various bands.

(3) A field that determines which band the data belongs to.

Subcode packs are marked by header bytes to transfer data blocks 53 that handle marked punctures, as described below.

FIG. 9 is a diagram showing the functions performed by the program 21. When the program 21 starts and runs, assuming that the order table was created in a previous session, it is loaded into memory by initialization 43. The order table is created by the program 21. It is a list of features in which case it is in time, ie its offset is shifted from the start of the main audio channel. The artist/operator is then presented with two screens. One screen displays a menu 45 specifying the operating systems supported by the program from which to choose. As shown in Figure 9, it includes Add Features 47, Edit/Delete/Move 49, Save/
These are load order information 51, conversion to subcode formant 15, data transfer 53, reproduction 55, and termination 57.

The program is in 4γ which adds features that are not present in any other mode. In this mode, the artist/operator sets offset times for features converted to subcode formants. In this connection,
In this embodiment of the program, the second screen displays a graphical representation of the features. For example, features can be represented as bars whose length varies depending on how long it takes to load the feature.

The artist/operator can also move features in time using needles, on-screen forces that allow the user to move the "pink amp" and bit pads that control the vines.

The edit/delete/move feature block 49 allows the user to modify or adjust the order table using word processor type editing techniques.

The save/load order information block 51 is responsible for writing the order table to a hard disk for puncture or setting the final order table.

The convert to subcode format block 53 transfers the subcode data from the various feature files into one target file and places the subcode data created by the subprogram 15 at the correct offsets designed by the program 21. put.

In particular, the data transfer block 53 reads the ordering table, opens the feature files in the appropriate order according to the ordering table, extracts the subcode data in the file, and sends it to the correct location determined at the specified offset. and distribute the data according to the band division information in the header in the feature file.

Reproduction block 55 allows the user to reproduce the subcode data through the graphics decoder using the data on the disk.

Exit block 57 allows the user to exit the program.

Block 2 containing the subprogram of block 15
1 program list is IBM AT
It is attached as Appendix 1, which is a 16-part listing of the object code in a format executable on a computer or equivalent computer.

Appendix 2 describes the band division described in this application (i.e.
501ji image and 5 lO% lyric bands) is a hex representation of a sample layout file 19.

[Brief explanation of the drawing]

The first decoy shows one subcode pack used to store one subcode graphical instruction; 3 shows the band division technique of the present invention into one band of one size and one band of another size, and FIG. 4 shows the manufacturing of a compact disc with subcode data. FIG. 5 shows a file created for use in ordering blocks when the band division technique of the present invention is used, and FIG. 6 shows a block diagram of a block containing certain band information. The first 20 ordered files created (by the program)
Figure 7 shows the first 20 records of the ordered file created by the program of blocks containing certain band information, and Figure 8 shows the conversion blocks to subcode format. Functional Block Diagram FIG. 9 is a functional block diagram of ordered file creation blocks organized into subcode backs.

Claims (6)

[Claims] (1) At least two sets of data in the subcode channel of a compact disc or laser disc having a main channel and a subcode channel with a start time,
encoding the encoded data in a separate band of the subcode channel for each said set of data; Apparatus for encoding at least two sets of data into subcode channels of a compact disc or laser disc for display on a video display device comprising: a) analog graphical data representing at least one image;
converting each of the at least one image into a digitized graphic data form having not more than 16 colors; and converting each image of the digitized graphic form into a first set of separate files; b) converting the binary data representing at least one line of lyric into a digitized graphical data form having not more than 16 colors for each of said at least one line of lyric; , and means for storing each at least one line of lyric of said digitized graphical form in a second set of separate files; c) said digitized graphical forms in said first set of separate files; converting at least one image of a data form and at least one line lyric of said digitized graphical form in said second set of separate files to a subcode format; Adding information specifying the band in which the data is to be placed, and including the band information in subcode format, each of the images in the subcode and each lyric line in the subcode format is respectively stored in a third set. means for storing in separate files and a fourth set of separate files; d) means for creating an ordered file containing each said image in said sub-code format and each said lyric line in said sub-code format; each said image in said sub-code format and each said lyric line in said sub-code format is associated with each file in said third set of files and each file in said fourth set of files. Apparatus for encoding at least two sets of data in subcode channels of a compact disc or laser disc ordered according to band information and a time offset from the start time of the main channel. (2) at least two sets of data in the subcode channel of a compact disc or laser disc having a main channel and a subcode channel with a start time;
encoding the encoded data in a separate band of the subcode channel for each said set of data; Apparatus for encoding at least two sets of data into subcode channels of a compact disc or laser disc for display on a video display device comprising: a) analog graphical data representing at least one image;
converting each of the at least one image into a digitized graphic data form having not more than 16 colors; and converting each image of the digitized graphic form into a first set of separate files. b) converting at least one image of said digitized graphical data form in said first set of separate files to a subcode format, and converting said data in said subcode format; Adding information specifying the bands to be placed and including the band information of the sub-code format, each image of the sub-code format and each of the band information of the sub-code format are combined into a second set of separate c) means for creating an ordered file containing each said image of said subcode format, wherein each said image of said subcode format is stored in a file of said second set; Apparatus for encoding at least two sets of data in a subcode channel of a compact disc or a laser disc ordered according to band information associated with the main channel and a time offset from a start time of the main channel. (3) at least two sets of data in the subcode channel of a compact disc or laser disc having a main channel and a subcode channel with a start time;
encoding the encoded data in a separate band of the subcode channel for each said set of data; Apparatus for encoding at least two sets of data into subcode channels of a compact disc or laser disc capable of being displayed on a video display device, comprising: a) binary data representing at least one line of lyric poetry; converting each lyric into a digitized graphical data form having not more than 16 colors; and converting each of the at least one line of the digitized graphical form into a second set of separate b) converting at least one line lyric of said digitized graphical data form in said first set of separate files into a subcode format; adding information specifying the band in which the data should be placed, and including the band information of the subcode format, storing each of the lyric lines of the subcode format in a second set of separate files; c) means for creating an ordered file containing each said lyric of said sub-code format, wherein each said lyric of said sub-code format is associated with each file of said second set. information and
Apparatus for encoding at least two sets of data in subcode channels of a compact disc or laser disc ordered according to a time offset from a start time of the main channel. (4) at least two sets of data in the subcode channel of a compact disc or laser disc having a main channel and a subcode channel with a start time;
encoding the encoded data in a separate band of the subcode channel for each said set of data; A method for encoding at least two sets of data in subcode channels of a compact disc or laser disc for display on a video display device comprising: a) analog graphical data representing at least one image;
converting each of the at least one image into a digitized graphic data form having not more than 16 colors; and converting each image of the digitized graphic form into a first set of separate files. b) converting the binary data representing at least one lyric into a digitized graphical data form having not more than 16 colors for each of said at least one lyric; and c) storing each of said at least one line of lyric in said digitized graphical form in a second set of separate files; c) said digitized graphic forms in said first set of separate files; converting at least one image of a graphical data form and at least one line lyric of said digitized graphical form in said second set of separate files to a subcode format; adding information specifying the band in which the data of the subcode format is to be placed, and including the band information of the subcode format, each of the images of the subcode format and each of the lyric lines of the subcode format are respectively d) creating an ordered file containing each said image in said sub-code format and each said lyric line in said sub-code format; and, each of the images in the sub-code format and each of the lyric poems in the sub-code format is
a compact disc or a laser disc ordered according to band information associated with each file in the set of files and each file in the fourth set of files, and a time shift from the start time of the main channel. A method of encoding two sets of data within a subcode channel. (5) at least two sets of data in the subcode channel of a compact disc or laser disc having a main channel and a subcode channel with a start time;
encoding the encoded data in a separate band of the subcode channel for each said set of data; A method for encoding at least two sets of data in subcode channels of a compact disc or laser disc for display on a video display device comprising: a) analog graphical data representing at least one image;
converting each of the at least one image into a digitized graphic data form having not more than 16 colors; and converting each image of the digitized graphic form into a first set of separate files. b) converting at least one image of said digitized graphical data form in said first set of separate files to a subcode format, and converting said data in said subcode format; each said image in said format and each said band information in said subcode format into a second set of separate files, adding information specifying the bands to be placed and including said band information in said subcode format; c) creating an ordered file containing each said image in said subcode format, each said image in said subcode format comprising:
at least two sets of data in subcode channels of a compact disc or laser disc ordered according to band information associated with each file of said second set and a time offset from the start time of the main channel; How to encode. (6) at least two sets of data in the subcode channel of a compact disc or laser disc having a main channel and a subcode channel with a start time;
encoding the encoded data in a separate band of the subcode channel for each said set of data; A method for encoding at least two sets of data in subcode channels of a compact disc or laser disc for display on a video display device, comprising: a) binary data representing at least one line of lyric poetry; converting each line of lyric into a digitized graphical data form having not more than 16 colors, and converting each of said at least one line of lyric of said digitized graphical form into a second set of lyric data; b) converting the at least one line lyric of the digitized graphical data form in the first set of separate files into a subcode format; adding information specifying the band in which the data of is to be placed and including the band information of the sub-code format and storing each of the lyric lines of the sub-code format in a second set of separate files; and c) creating an ordered file containing each said lyric in said sub-code format, wherein each said lyric in said sub-code format has band information associated with each file in said second set. and,
A method of encoding at least two sets of data in subcode channels of a compact disc or laser disc ordered according to a time offset from the start time of the main channel.