1、European Telecommunications Standards Institute ETC CF3 ETSI EUROPEAN TELECOMMUNXCATION STANDARD Videotex presentation layer protocol Videotex presentation layer data syntax. . - European Telecommunications Standards Institute BP 52 F-06561 VALBONNE CEDEX _ - - , CEPT T/GT*TE*10 (88)*64 88 W 2326414
2、 0011052 258 W NOTE Some references in the draft standards submitted to the third Technical Assembly reflect the fact that the texts were initially produced in CEPT study groups. For practical reasons it has not always been possible to re-edit the texts appropriately, but this will be done after the
3、 Technical Assembly has taken its decisions on the basic contents of the texts. The ETSI Secretariat will propose a numbering system for ETSI standards to the Technical Assembly. If this is adopted all I- ETS and ETS-approved will be given an ETSI standard number and references to the CEPT numbering
4、 system will be abandonned. CEQT T/GT*TE*lO (88)*b4 88 2326434 0031053 394 W ETSI TC TE T/GT TE lO(88) 64 SOURCE : EDITOR OF T/TE 06-01 (Videotex Services) TITLE : PROPOSED AMENDMENTS TO RECOMMENDATION T/TE 06-01 This document contains amendments and additions to Recommendation T/TE 06-01. New text
5、is denoted by a change bar in the margin. (Note: ETSI TA is only being asked to adopt the amendments and additions and will need to consider later bringing the original recommendations into its family of ETSs. This is a pragmatic solution to enable the more recent progress in the Technical Committee
6、 TE to be recognized within the ETSI approval rules). - -_ * CEPT T/GT*TE*LO (88)*64 88 2326434 0011054 020 I I Recommendation T/TE 06-01 (formerly Recommendation T/CD 06-01) . (Innsbruck May 1981) (Revised, Cannes, September 1983) (Revised, Montpellier, June 1984) (Revised, Nice, June 1985) (Revise
7、d, Edinburgh, May 1988) (Revised, October 1988) CONCERNING THE VIDEOTEX SERVICE The European Telecomnunucations Standards Insti tute Considering: - the work undertaken within CEPT with a view to harmonising international telecommunication services as well as equipment - studies carried out within th
8、e framework of question CD7 - the possible benefit to the expansion of the Videotex service in providing stable environment for the full commercial exploitation of existing services already implemented - the possibility that some administrations require a lower cost basic service and others an enhan
9、ced service with extra facilities I - the need for a common standard which will enable administrations rho wish to do so to confidently adopt the “harmonised enhanced“ service or up grade a basic service to the “harmonised enhanced“ service - the need to leave the way open to add new facilities as t
10、echnology progresses in a way which preserves investments in basic services or enhanced services. Adopts the present standard , which implies that : 1 In order to facilitate international access between Videotex services in Europe : 1.1 provided international gateways. International access to nation
11、al Videotex services should be via PTT 1.2 communication protocols to be adopted by CEPT, the information being coded according to data syntax described in Annex A, with the range of information transmitted restricted to conform to the service reference model as described in Annex B. International g
12、ateways should intercommunicate using the 1.3 Administrations should ensure that the coded information is transcoded as necessary in order to provide the best possible display on the terminals in use in that country. In addition, Administrations may provide identification of user and billing. - - -
13、CEPT T/GT*TE*1O (88)*b4 88 m 2326414 0011055 Tb7 = . 2 of Videotex Services: In order recognise existing systems and to harmonise further development 2.1 profiles described in Annex C (see Fig la) Systems offering a basic service shall be based on one of the four 2.2 are provided they shall conform
14、to the standards referred to in Fig lb, 2.3 New enhanced services which are either as yet unforeseen or not yet defined in sufficient detail in Annex B to make a recommendation at this stage shall be formulated such that they are: An enhanced service of foreseen facilities is optional but where they
15、 I enhanced“ se rv i ce based on one of the four basic building blocks and the “harmonised or based on one of the four basic building blocks and be able to display information generated by systems using the “harmonised enhanced“ service c tandard; II in the references given in Fig lb. able to be ado
16、pted without modifications to any parameters defined 2.4 a, Either new optional enhanced services which are either as yet unforeseen or not yet defined in sufficient detail in Annex B sliall not be added to a system providing the basic service without also including the “harmonised enhanced“ service
17、 referred to in Fig lb. b. Or new optional enhanced services which are either as yet unforeseen or not yet defined in sufficient detail in Annex B (Fig lc) may be adopted without also adopting the facilities of the “harmonised enhanced service standard referred to in Fig lb. In this case at least fu
18、ll compatibility with CEPT Recommendation T/CD 06-01 version Innsbruck (May 1981) shall be assumed. -* However it is preferable for both lb and IC in Figure 1 to be adopted if maximum inter-working between services is to be achieved at the earliest possible time. 3 Studies should continue on: - New
19、enhanced services which are not yet defined in sufficient detail in Annex B (photographic modes) so as to arrive at a common standard for them. - International communication protocol. 4 communication between external computers and Videotex centres, administrations should adopt the data syntax descri
20、bed in Annex A for the coding of information and common protocols for the other layers (possibly those referred to in 1.2 above). In order to harmonise the interface to “external computersn for 2 - - * CEPT T/GT*TE*1O (BB)*64 B8 m 2326414 0011056 9T3 m FUTURE HORIZON Fig IC STANDARD FOR NEW E“CED SE
21、RVICES AS YET UNFORESEEN OR NOT YET DEFISED 1s SERVICES (OPTIONAL) - must be based on one of the four basic building blocks and “harmonised enhanced“ service or must be based on one of the four basic building blocks and be able to display information generated by systems using the harmoniced enhance
22、d service standard. - must be able to be adopted without modifications to any parameters defined in the references given in Fig lb 1ST HORIZON / / Fig lb Il T STANDARD FOR THE “HARMONISED ENHA“ED“ SERLICE (OPTIONAL) Annex B O 6 1.1.2 6.2.2 1.3.2 8 1.4.1 and 1.4.2 (simultaneously) 10 1.4.3 to 1.4.5 1
23、.5 to 1.9 4 5 II Fig la FLEXIBLE INITIAL BUILDING BLOCKS (alternatives) Profile 1 Profile I Profile I Profile See Rec 2.4 (Option FIG 1 - CEPT RECOMMENDATION ON ENHANCED VIDEOTEX SERVICE IVYD ITS RELATIOSSHIP WITH EXISTING BASIC VIDEOTLY SERVICE SYSTEMS AND NEW AS YET WDEFIBED FACILITIES 3 -.- - I -
24、 ,CEPT T/GT*TE*LO (88)*64 88 M 2326414 OOL1057 83T m I Annex A to Recommendation T/TE 06-01 (formerly T/CD 06-01) Note 1: Note 2: This annex is an integral part of the recommendation. All references to T/CD should be interpreted as T/TE. CEPT VIDEOTEX PRESENTATION LAYER DATA SYNTAX Issue 6, October
25、1988 (A Revision of Issue 5, Edinburgh, May 1988) CEPT T/GT*TE*KlrO (88)*b4 88 ICI 232b414 0011058 776 VIDEOTEX PRESENTATION LAYER DATA SYNTAX CONTENTS PART O .- PART 1 PART 2 PART 3 PART 4 PART 5 PART 6 GENERAL 1 INTRODUCTION . , . , , , . . . . . . . . . . . 1 2 REFERENCES . , . , . . . . . . . .
26、. . . . . . 5 3 DEFINITIONS . . . . . , . . . . . . . . . . . . 6 ALPHA MOSAIC DISPLAYS 1 DESCRIPTION . . . . . . . . . . . . . . . . . . 1 2 REPERTORY , . 18 3 CODING STRUCTRE . . . . . . . . . . . . . 70 APPENDIX A IDENTIFICATION SYSTEM APPENDIX B WAHPLES OF TSME DEPENDENCII IN mt UNIFIED ALPHAMOS
27、AIC MODEL GEOMETRIC DISPLAYS Refer to T/TE 06-02 PHOTOGRAPHIC DISPLAYS 1 INTRODUCTION . . . . . . . . . . . . . . . . . 1 2 PHOTOGRAPHIC PIXEL HEADER UNIT (PPH) . , . . . 5 3 PHOTOGRAPHZC PIXEL TRANSFER UNIT (PPTU) , . . 12 4 PHOTOGRAPHIC TABLE HEADER UNIT . , . , , , , 14 5 PHOTOGRAPHIC TABLE TRANS
28、FER UNIT . . . , . . 16 APPENDIX A DPCH MACE CODING - ONE DIMENSIONAL APPENDIX B DCT IMAGE CODING - Tu0 DIMENSIONAL Defina DYNAMICALLY REDEFINABLE CHARACTER SETS 1 XNiRODUCTIN . . . . . . . . . . . . . . . , . 1 2 DRCSHEADERUNITS. ,. . . . . . . . , , . . 2 3 PATTERNTRANSFERUNITS . . . . . . . . . 6
29、 4 CODING METHODS . . . . . . . . . . . . . , . 7 5 DESIGNATION AND INVOCATION OF DRCS , , . , . 14 6 APPLICAEiILIY OF ATTRIBUTES . . . . . , . . . 15 Define COLR 1 INTRODUCTION . . . . . . . . . . . . . , . . 1 2 COLOUR SYSTEM EXTENSION . . . , . . . . . . . . 1 3 CODING OF REDEFINABLE COLRS . . .
30、. . . , . . 3 Define FORMAT 1 INTRODUCTION . . . . . . . . . , . . . . . . 1 2 CODING . . . . *. . . . . , . , . , . . , . 1 3. DEFAULTS . o . . . . e . , . , , . , , , , . 1 = - CEPT T/GT*TE*lO (881864 88 W 2326414 0011057 602 PART 7 TRANSPARENT Data - Refer to T/TE 06-03 PART 8 RESET 1 INTRODUCTIO
31、N . 1 2 CODING STRUCTURE . 1 3 FUNCTIONAL DESCRIPTION AND CODING . 1 PART 9 PROCESSAE _. I. . - CPT T/GT*TE*lO (88)*b11 8 23264111 0011073 T82 VIDEOTEX PLDS Part 1 (Alph? Mosaic Displays) Page 2 PARALLEL ATTRIBUTES Parallel attributes are the property of the active position and move it under the act
32、ion of format effectors or spacing display characters (including space). They apply to the displayed characters subsequently received until the attributes are changed by relevant controls including certain format effectors (CS,APA,APH). They also apply to spacing display characters (including space)
33、 inserted by control commands. SERIAL ATTRIBUTES Serial attributes are set between markers on a row. They apply from the position of the active position at the time they are received to the end of the row or until a contradictory marker is reached. with WRAPAROUND CONTROLS Wraparound controls compri
34、se a set of rules which govern what happens when the active position attempts to move off the defined display area. 1.1.2 Format The default format is 24 rows of 40 columns with automatic wraparound on rows and columns. The format and wraparound may be changed by the Define FORMAT VPDE , 1.1.3 Chara
35、cters Alphanumeric, block mosaic, smoothed mosaic and line drawing characters are defined. Accented characters are coded using the composition method of coding, The fixed repertoire of characters may be extended with dynamically redefinable characters loaded via the Define DRCS VPDE. 1.1.4 Format Ef
36、fectors Characters may be positioned within the defined display area by means of format effector controls which move the active position, usually in units of one character position. 1.1.5 Attributes The presentation of characters on the screen may be modified by the application of display attributes
37、. Attributes may be applied to the full screen, full row, part of a row (serial) or to subsequently printed characters (parallel). VIDEOTEX PLDS Part 1 (Alpha Mosaic Displays) Page 3 1.1.6 Device Control Functions The action of scrolling, the display of the cursor and similar functions may be contro
38、lled by codes transmitted to the terminal. - CEPT T/GT*TE*10 (88)*b4 88 m 2321,414 0011075 855 VIDEOTEX PUS Part 1 (Alpha Mosaic Displays) Page 4 1.2 Theoretical Terminal Model . The videotex service, alphamosaic option, may be described in the form of an ideally perfect theoretical terminal. This m
39、odel is detailed hereafter. 1.2.1 Description The theoretical terminal model is based on a separation between the visual content of the page and its structure. It can be described as if it were composed of three memories. 1. 2. 3. One character memory where one character address from the character g
40、enerator is stored at every character location. One attribute memory where all the attributes are set in parallel at every location of the screen plus registers for full screen and full row background. The number of registers in this memory is equal to the number of rows plus two. The last two regis
41、ters refer to the top segment (above the defined display area) and the bottom segment (below the defined display area) of the full screen background. One marker memory where every attribute or group of attributes or display functions may be flagged at any character location. When an attribute or fcn
42、ction is modified according to the serial mode, this modification occurs between the current character location and the next flag related to this attribute or function (or up to the end of the row). . 1.2.2 Operation of Parallel and Serial Mode Controls Both the pazallel and serial modes set only se
43、rial attribu?ec in Transp. (cl Normal (cl Transp, (c - re sultan t a I Foreground of defined display area character layer (c) Background of the defined display area character layer (b) Full screen background layer (a) VIDEOTEX PUS Part 1 (Alpha Mosaic Displays) Page 8 1.3 Defined Attributes and Qual
44、ified Areas 1.3.1 FOREGROUND COLOUR This is the colour of the graphics shape being displayed. The colour may be any colour from the available colour tables including transparent in which case the full screen background colour (or the geometric or photographic layers if present) is seen. 1.3.2 BACKGR
45、OUND COLOR CHARACTER BACKGROUND COLOUK This is the colour of the remaining area of the character cell. The colour may be any colour from the available colour tables or be transparent in which case the full screen background colour (or the geometric or photographic leyers if present ) is seen. FULL S
46、CREEN or mrU ROW BACKGROUND COLOR This is the colour of layer (a) of the theoretical model, see section 1.2.3. 1.3.3 LINED Alphanumeric characters are displayed with an underline in which the underline is considered to be part of the shape of the graphics character, Mosaic characters and line drawin
47、g characters are displayed in separated font, see section 2.1.2. t 1.3.4 SIZE There are four states of character size: I. NORMAL- SIZE The extent of characters occupies the active position. DOUBLE-HEIGHT Theextent of characters occupies both the active position and the corresponding position of the
48、adjacent row. DOUBLE-WIDTH The extent of characters occupies both the active position and the next position of the same row. DOUBLE-SIZE The extent of characters occupies the active position, the next position on the same row and the corresponding two positions on the adj acent row. See section 1.4
49、for rules for the application of the SIZE attribute. VIDEOTEX PLDS Part 1 (Alpha Mosaic Displays) Page 9 1.3.5 FLASH The following attribute states are defined: STEADY The characters are displayed normally. FLASHING NORMAL FLASH The characters are displayed alternately in the prevailing foreground colour and in the prevailing background colour. INVERTED FLASH This is as for FLASH but on the inverted phase of the flashing clock. REDUCED INTENSITY FLASH (flash between colour tables) The characters are displayed alt
