A Unicode text file prepared using the Microsoft WordPad program with the text file containing some Private Use Area codes for customizing an interactive multimedia DVB-MHP application. This file is not a Unicode text file, it is an ordinary 8-bit text file, provided as documentation of the experiment. The Unicode text file of the experiment is a file named unitest4.txt. The experiment is to upload a Unicode text file, the content of which is in a form which hopefully would be suitable for broadcasting upon a DVB-MHP channel so as to customize a Java program which acts upon some (all?) of the codes listed later in this document. That Java program is not as yet written and it is not a program which I presently have the knowledge, skill and facilities to produce. My knowledge of Java is fairly basic, though I could hopefully produce a web-based applet which could give a simulated display of some of the effects. The idea is that, in a program such as Microsoft WordPad running on a PC at content-authoring time, the Private Use Area characters below would simply be displayed as distinctive symbols. Yet when processed using a Java program written for the purpose, they would not be displayed yet would produce the effects specified. For example, U+F3E4, decimal 62436, YELLOW would cause all subsequent text to be yellow until some other colour code were encountered. The code U+EBC9, decimal 60361, WAIT FOR A BUTTON PUSH AND ACT UPON IT is a wait for any button from amongst those which the program can detect being pushed and to then skip forward over all characters until either a matching marker is found (for red, green, yellow, blue, magenta, orange or enter) or until the ANY BUTTON MARKER is encountered, whereupon production of the display continues from that place. Please note that a magenta button and an orange button will not be available on minimum DVB-MHP televisions, yet the codes are provided for completeness, and indeed in the hope that maybe the European Union interactive television will be defined to have six coloured buttons and that the six colours may be as here suggested: such a decision would be entirely compatible with the DVB-MHP specification which defines a minimum system and various options and leaves to local implementations the specific choice of options. However, one locality for a local implementation could indeed be the whole of the European Union, so maybe the six coloured buttons will be implemented throughout the European Union when the decision is made as to what should be the level of the European Union interactive television implementation of the DVB-MHP specification. A content author may use codes such as U+EBD8, decimal 60376, SKIP UNTIL CONTINUE MARKER and U+EBD9, decimal 60377, CONTINUE MARKER to steer the operating point through the file, so that when the responses for, say, pushing a red button and pushing a green button, produce mutually exclusive routes through the display sequence those routes may be expressed within a linear file. One simply has a marker for a particular colour, then what should happen for that colour button then a U+EBD8, decimal 60376, SKIP UNTIL CONTINUE MARKER and then a marker for another colour, then what should happen for that colour button then a U+EBD8, decimal 60376, SKIP UNTIL CONTINUE MARKER and so on for each colour which has a particular action and then a U+EBD7, decimal 60375, ANY BUTTON MARKER followed by the action to take for all other button pushes. Please note that U+EBD7, decimal 60375, ANY BUTTON MARKER would not, in a well-structured file of characters, be reached by the operating point if a marker specific to the button pushed had been encountered as the U+EBD8, decimal 60376, SKIP UNTIL CONTINUE MARKER would cause the U+EBD7, decimal 60375, ANY BUTTON MARKER to be disregarded as the Java program would be skipping until a U+EBD9, decimal 60377, CONTINUE MARKER were encountered. A U+EBD9, decimal 60377, CONTINUE MARKER is intended as the place of flows through the various routes meeting, ready to accept the next response from the end user without any reference to what has gone before. U+EBC0, decimal 60352, RETURN U+EBC1, decimal 60353, NEW PAGE U+EBC2, decimal 60354, PAGE HOME U+EBC3, decimal 60355, LOWER PANEL HOME. U+EBC7, decimal 60359, EXIT U+EBC8, decimal 60360, WAIT FOR BUTTON PUSH U+EBC9, decimal 60361, WAIT FOR A BUTTON PUSH AND ACT UPON IT U+EBD0, decimal 60368, RED MARKER U+EBD1, decimal 60369, GREEN MARKER U+EBD2, decimal 60370, YELLOW MARKER U+EBD3, decimal 60371, BLUE MARKER U+EBD4, decimal 60372, MAGENTA MARKER U+EBD5, decimal 60373, ORANGE MARKER U+EBD6, decimal 60374, ENTER MARKER U+EBD7, decimal 60375, ANY BUTTON MARKER U+EBD8, decimal 60376, SKIP UNTIL CONTINUE MARKER U+EBD9, decimal 60377, CONTINUE MARKER U+EBDA, decimal 60378, SKIP UNTIL CHAPTER MARKER U+EBDB, decimal 60379, CHAPTER MARKER U+EBDC, decimal 60380, SKIP UNTIL CONCLUSION MARKER U+EBDD, decimal 60381, CONCLUSION MARKER U+EBCC, decimal 60364, OBJECT REPLACEMENT CHARACTER SYNONYM LEFT ALIGNMENT U+EBCD, decimal 60365, OBJECT REPLACEMENT CHARACTER SYNONYM CENTRE ALIGNMENT U+EBCE, decimal 60366, OBJECT REPLACEMENT CHARACTER SYNONYM RIGHT ALIGNMENT U+EBCF, decimal 60367, OBJECT REPLACEMENT CHARACTER SYNONYM U+F3AC, decimal 62380, SET NEW BACKGROUND COLOUR U+F3BA, decimal 62394, SET TO GENERAL COMPUTING DEFAULT COLOURS. (which, for a two-colour system is black on white) U+F3BB, decimal 62395, SET TO DVB-MHP COMPUTING DEFAULT COLOURS. (which, for a two-colour system is cyan on black) U+F3BC, decimal 62396, HEADING 36 POINT U+F3BD, decimal 62397, SUBTITLE 31 POINT U+F3BE, decimal 62398, BODY 26 POINT (THE DEFAULT SIZE FOR DVB-MHP) U+F3BF, decimal 62399, FOOTNOTE 24 POINT U+F3E0, decimal 62432, BLACK U+F3E1, decimal 62433, BROWN U+F3E2, decimal 62434, RED U+F3E3, decimal 62435, ORANGE U+F3E4, decimal 62436, YELLOW U+F3E5, decimal 62437, GREEN U+F3E6, decimal 62438, BLUE U+F3E7, decimal 62439, MAGENTA U+F3E8, decimal 62440, GREY U+F3E9, decimal 62441, WHITE U+F3EA, decimal 62442, CYAN U+F3EB, decimal 62443, PINK U+F3EC, decimal 62444, DARK GREY U+F3ED, decimal 62445, LIGHT GREY U+F3EE, decimal 62446, LAVENDER U+F3EF, decimal 62447, MINT The font mentioned later in this document also has thirteen other glyphs in this series. However, these are for a more advanced system and are only mentioned now as the glyphs are in the font for research purposes. The general idea is that a number, encoded as a sequence of characters in the range U+EBF0 through to U+EBF9, decimal 60400 through to decimal 60409, would immediately precede a U+EBDE, decimal 60382, SKIP UNTIL NUMBER MARKER and immediately precede a U+EBDF, decimal 60383, NUMBER MARKER and the two could be used to produce a jump to any numbered point in a multimedia presentation. However, that system would involve a qualitative difference from the system using the 48 codes above as the 48 codes above could all be used in a one-pass sequential interpretation of a Unicode text file by a generic DVB-MHP Java application: using the number marker could mean rewinding the file and searching all through it each time a jump is produced, so that facility is not suggested at present. In addition, U+EBDF, decimal 60383, NUMBER MARKER could be used as the destination of a U+EBCA, decimal 60362, WAIT FOR A NUMBER AND ACT UPON IT whereby a number would be entered by an end user (that is, the television viewer) by pushing digit buttons followed by the ENTER button. As the research develops hopefully these thirteen characters can be used and also other characters can be devised for keeping points score in quiz type applications, such as by having a code for adding one to a running total and so on: of necessity this would mean that the generic Java program needed to interpret the codes would get larger and more complex. However, the 48 codes above seem a set suitable to be a plateau level for trying to get a generic software package, a Java program, implemented to run upon a DVB-MHP television, so that the one Java program may be run with a number of different Unicode text files used to customize it, thereby producing a number of multimedia presentations which act as if they are independent applications, when, behind the scenes they are all simply different customizations of the same Java program. If the production of that Java program can be achieved, available for all DVB-MHP broadcasters to use if they choose to use it, then I feel that a great step forward will be achieved in applying the DVB-MHP system to distance education in particular and possibly to other applications as well. U+EBCA, decimal 60362, WAIT FOR A NUMBER AND ACT UPON IT U+EBDE, decimal 60382, SKIP UNTIL NUMBER MARKER U+EBDF, decimal 60383, NUMBER MARKER U+EBF0, decimal 60400, MULTIMEDIA AUTHORING DIGIT 0 U+EBF1, decimal 60401, MULTIMEDIA AUTHORING DIGIT 1 U+EBF2, decimal 60402, MULTIMEDIA AUTHORING DIGIT 2 U+EBF3, decimal 60403, MULTIMEDIA AUTHORING DIGIT 3 U+EBF4, decimal 60404, MULTIMEDIA AUTHORING DIGIT 4 U+EBF5, decimal 60405, MULTIMEDIA AUTHORING DIGIT 5 U+EBF6, decimal 60406, MULTIMEDIA AUTHORING DIGIT 6 U+EBF7, decimal 60407, MULTIMEDIA AUTHORING DIGIT 7 U+EBF8, decimal 60408, MULTIMEDIA AUTHORING DIGIT 8 U+EBF9, decimal 60409, MULTIMEDIA AUTHORING DIGIT 9 The provision of the four OBJECT REPLACEMENT CHARACTER SYNONYM characters will hopefully mean that the set of characters has scope for providing a great number of interactive multimedia presentations. The file unitest4.txt can conveniently be displayed on a PC using the Microsoft WordPad program provided that the version of WordPad can support a Unicode text file. The file unitest4.txt was prepared on a Windows 98 PC system. Using the Quest text font, at least version 1.07, allows the authoring-time symbols for these Private Use Area codes to be displayed as symbols. The font is available for download from the following web page. http://www.users.globalnet.co.uk/~ngo/font7007.htm Please note that these particular assignments of these Private Use Area codes are produced by the present author. Other researchers in other contexts may choose to assign them differently. However, if people do choose to use the codes which I have specified in relation to DVB-MHP broadcasting then that is fine and will help interoperability. Please note also that these Private Use Area code meanings have no status within the DVB-MHP specification. They only have validity in those application programs which recognize their use within that program. Hopefully this experiment will be of interest to readers and will be a catalyst towards progress. William Overington 26 May 2003