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- A.3.12.1.9 W-set segment transparent
- W-Set-Seg-Transparent ::= SEQUENCE { transparent-segment-number [1]
- INTEGER,
- transform-matrix [2] MAT }
- -- Set transformation matrix attributes for the identified segment.
- MAT ::= SET { matrix-element-11 [11] REAL,
- matrix-element-12 [12] REAL,
- matrix-element-13 [13] REAL,
- matrix-element-21 [21] REAL,
- matrix-element-22 [22] REAL,
- matrix-element-23 [23] REAL }
- -- Transform Matrix Definition.
- A.3.12.1.10 W-set priority
- W-Set-Priority ::= SEQUENCE { priority-segment-number [1]
- INTEGER,
- priority-value [2] REAL }
- -- Set segment priority attribute for the identified segment. This is
- analogous to display order priority.
- A.3.12.2 Work station independent
- Work-Station-Independent ::= CHOICE { [1] W-Associated,
- [2] W-Copy,
- [3] W-Insert }
- A.3.12.2.1 W-associated
- W-Associated ::= SEQUENCE { associated-w-station-id [1] INTEGER,
- associated-segment-number [2] INTEGER }
- -- Associate the identified segment with the identified work station.
- A.3.12.2.2 W-copy
- W-Copy ::= SEQUENCE { copy-w-station-id [1] INTEGER,
- copy-segment-number [2] INTEGER }
- -- Copy the primitives of the identified work station.
- A.3.12.2.3 W-insert
- W-Insert ::= SEQUENCE { insert-segment-number [1] INTEGER,
- insert-transform-matrix-ref [2] MAT }
- -- Transform and display segment.
- A.3.13 Colour control string
- All of the source terminal data syntaxes provide the
- capability to define colour and have available, at least
- optionally, a colour map capability. However the colour model which
- is used by each of the source terminal data syntaxes differs
- significantly. In order to provide a neutral basis for colour, the
- colour model developed for ISO 8613 Text and Offices Systems -
- Office Document Architecture is used here.
- s
- syntaxes support colour models which are different from this, the
- mapping of the specific colour models to the basic RGB colour cube
- must be understood by the conversion process.
- Two colour indexing modes are available: Direct and Indexed.
- In direct colour selection, the colour is defined by providing a
- three tuple of discrete values for the RGB components. In the
- indexed colour selection mode, the colour is defined by an index
- into a single colour table of discrete colour values. The number of
- colours which may be defined in the colour table is terminal model
- dependent. The limit assumed in the definition of a particular set
- of data is specified in the Boundary Value Definition section. If a
- receiving system cannot image the range of colour values specified
- by a direct colour value or the colour value indexed by a colour
- index, then a `closest match` is assumed according to the criteria
- stated in ISO 8613. A variant of the indexed colour mode called
- `auxiliary colour mode` is used to define a colour for the
- background of a text or mosaic character cell.
- Colour-Control-String ::= CHOICE { [1]
- Basic-Colour-Selection,
- [2] Direct-Colour-Selection,
- [3] Indexed-Colour-Selection,
- [4] Auxiliary-Colour-Selection,
-
-
-
-
- Fascicle VII.5 - Rec. T.101 PAGE45
-
- [5] Colour-Index-Setup }
- A.3.13.1 Basic colour selection
- Basic-Colour-Selection ::= INTEGER { black (0),
- red (1),
- green (2),
- yellow (3),
- blue (4),
- magenta (5),
- cyan (6),
- white (7),
- auxiliary-black (8),
- auxiliary-red (9),
- auxiliary-green (10),
- auxiliary-yellow (11),
- auxiliary-blue (12),
- auxiliary-magenta (13),
- auxiliary-cyan (14),
- auxiliary-white (15),
- auxiliary-foreground (16) }
- e
- expressed in terms of the abstract colour by the conversion
- process. That is, all the rules inherent in the serial
- attribute method of specifying basic colours, or in the
- parallel attribute method, should be resolved by the
- conversion process which creates the IDS colour commands.
- VV The auxiliary colour commands specify the background colour
- for text and mosaics. The command `auxiliary foreground`
- specifies that the background colour should be set to the
- current foreground colour.
- A.3.13.2 Direct colour selection
- DirectVColourVSelection ::= SEQUENCE { REAL, REAL, REAL }
- VV Direct colour selection permits colours to be specified in
- terms of the Red Green Blue components of the colour model.
- The ASN.1 REAL data type is use since this form of number is
- selfVdelimiting and of arbitrary length. The real number
- parameters are relative to the maximum colour value for each
- component. The parameters are Red, Green and Blue
- respectively.
- A.3.13.3 Indexed colour selection
- IndexedVColourVSelection ::= INTEGER
- VV Indexed colour selection permits colours to be specified as an
- index into an indirect colour map, which contains actual Red,
- Green and Blue colour specifications for each colour. The
- length of the colour map and the number of colour maps
- available is terminal model dependent. The INTEGER parameter
- is interpreted with respect to the current size of the colour
- map specified in Boundary Value Definition. In order to
- accommodate the rules for accommodating differences in the
- colour value extent, as specified in ISO 8613, the INTEGER
- parameter is interpreted as a normalized fraction of the
- specified map lenght. Some terminal data syntaxes provide the
- capability of multiple colour maps. Multiple maps are
- logically equivalent to one large map encompassing a number of
- submaps. In the IDS, the use of several colour maps is handled
- by arbitrarily partitioning the single IDS colour map.
- A.3.13.4 Auxiliary colour selection
- AuxiliaryVColourVSelection ::= INTEGER
- VV Auxiliary colour selection permits colours to be specified for
- the background of Text or Mosaics character cells. The
- operation of this command is similar to the Indexed Colour
- selection above, except that the current backgroun colour is
- established.
- A.3.13.5 Colour index setup
- Colour-Index-Setup ::= SEQUENCE { INTEGER, REAL, REAL, REAL }
- -- The Colour Index setup command defines the contents of the
-
-
-
-
- PAGE50 Fascicle VII.5 - Rec. T.101
-
- colour map. The first parameter takes indexes into the colour
- map in a similar manner to the Indexed Colour Selection
- command. The remaining three parameters define the Red, Green
- and Blue colour values in a manner similar to the Direct
- Colour Specification command.
- A.3.14 Text colour string
- The manner in which text is presented and the specialized
- attributes and constraints which pertain to the presentation of
- texts differs between each of the terminal data syntaxes.
- Text-Control-String ::= CHOICE { [1] General-Text-Control,
- [2] Word-Wrap-Control }
- A.3.14.1 General text control
- General-Text-Control ::= SEQUENCE { [1]
- General-Text-Control-Code,
- [2] G-Text-Par1 OPTIONAL,
- [3] G-Text-Par2 OPTIONAL,
- [4] Rel-Coord OPTIONAL,
- [5] Abs-Coord OPTIONAL }
- General-Text-Control-Code ::= GRAPHICSTRING
- -- General control function from Recommendation T.101 DS III [PDI
- G Set position 2/2, (10/2)].
- -- Note - PDI G Set has final character 5/7 within DS III.
- G-Text-Par1 ::= SET { [1] Char-Rotation OPTIONAL,
- [2] IMPLICIT Char-Path OPTIONAL,
- [3] Char-Spacing OPTIONAL,
- [4] IMPLICIT Text-Precision OPTIONAL,
- [5] IMPLICIT Char-Expansion-Factor OPTIONAL,
- [6] Text-Colour-Index OPTIONAL,
- [7] IMPLICIT Text-Alignment OPTIONAL }
- Char-Rotation ::= CHOICE { predefined [1] IMPLICIT
- INTEGER {
- char-rotation-0
- (0),
- char-rotation-90
- (1),
- char-rotation-180 (2),
- char-rotation-270 (3) }
- continuous [2] IMPLICIT SEQUENCE {
- height-vector Abs-Coord,
- width-vector Abs-Coord } }
- Char-Path ::= INTEGER { char-path-right (0),
- char-path-left (1),
- char-path-up (2),
- char-path-down (3) }
- Char-Spacing ::= CHOICE { predefined [1] IMPLICIT INTEGER {
- char-spacing-1 (0),
- char-spacing-5/4
- (1),
- char-spacing-3/2
- (2) }
- continuous [2] IMPLICIT REAL }
- Text-Precision ::= INTEGER { string (0),
- char (1),
- stroke (2) }
- Char-Expansion-Factor ::= REAL
- Text-Control-Index ::= CHOICE { [1] IMPLICIT
- Basic-Colour-Selection,
- [2] IMPLICIT Indexed-Colour-Selection }
- Text-Alignment ::= SEQUENCE { Horizontal-Alignment,
- Vertical-Alignment }
- Horizontal-Alignment ::= INTEGER { normal (0),
- left (1),
- centre (2),
- right (3) }
- Vertical-Alignment ::= INTEGER {normal (0),
-
-
-
-
- Fascicle VII.5 - Rec. T.101 PAGE45
-
- top (1),
- cap (2),
- half (3),
- base (4),
- bottom (5) }
- G-Text-Par2 ::= SEQUENCE { INTEGER { cursor-style-underscore
- (0),
- cursor-style-block
- (1),
- cursor-style-cross-hair
- (2),
- cursor-style-custom
- (3) }
- INTEGER{cursor-&-geometric-drawing-
- position-together
- (0),
- cursor-leads-geometric-
- drawing-position
- (1),
- geometric-drawing-position
- -leads-cursor
- (1),
- cursor-&-geometric-drawing-
- position-separate
- (3) }
- INTEGER { char-interrow-spacing-1
- (0),
- char-interrow-spacing-5/4
- (1),
- char-interrow-spacing-3/2
- (2),
- char-interrow-spacing-2
- (3) }
- Char-Block-Dimension }
- -- The relative coordinates define the size of the character
- field.
- Char-Block-Dimensions ::= Rel-Coord
- A.3.14.2 Word wrap control
- on
- one of the terminal data syntaxes. This capability cannot be
- directly converted to other data syntaxes; however, the effect can
- be achieved in the converter by issuing appropriate format effector
- characters.
- WordVWrapVControl ::= INTEGER { WordVWrapVOn (1),
- WordVWrapVOff (2) }
- VV WordVWrapVOn is a function from Recommendation T.101 DS III
- [C1 set position 5/5, (9/5)].
- VV WordVWrapVOff is a function from Recommendation T.101 DS III
- [C1 set position 5/6, (9/6)].
- A.3.15 Photographic string synthetic image
- All of the terminal data syntaxes provide a method of handling
- an array of pixels. Some of the data syntaxes also provide general
- photographic capabilities which provide more efficient methods of
- encoding the same type of data. This means that interworking
- between all of the terminal data syntaxes is possible for
- photographic data, even though it may be inefficient in some cases.
- Two classes of photographic images are identified below. They
- are the Synthetic and the Natural Image forms of photographic. The
- synthetic form of photographic corresponds to the photographic
- capabilities of data Syntax I. Natural Image photographic coding is
- for further study.
- PhotoVGraphicVStringVSyntheticVImage ::= CHOICE { [1]
- LineVDotVPattern,
- [2] LineVDotVPatternVComp,
- [3] FieldVDotVPattern,
-
-
-
-
- PAGE50 Fascicle VII.5 - Rec. T.101
-
- [4] ColouringVBlock,
- [5] ColouringVBlockVComp,
- [6] FieldVColouringVBlock,
- [7] FieldVColouringVBlockVComp,
- [8] FreeVFormatVColouringVBlock }
- VV Photographic Synthetic Image functions correspond to
- Recommendation T.101 Data Syntax I. These functions are
- suitable for displaying synthetic images such as Kanji
- characters, graphics, etc.
- A.3.15.1 Line dot pattern
- LineVDotVPattern ::= SEQUENCE {
- yVoriginVpointVcoordinateVIdp AbsVCoord,
- dotVpatternVdataVIdp BITSTRING }
- VV LineVDotVPattern functions indicates a selection of two
- colours which are defined by a colouring Block, Field
- Colouring Block, etc. This function gives dot pattern data of
- one or several lines at a time.
- A.3.15.2 Line dot pattern comp
- LineVDotVPatternVComp ::= SEQUENCE {
- yVoriginVpointVcoordinateVIdpc AbsVCoord,
- mhVrunVlength codedVdata BITSTRING }
- VV The LineVDotVPatternVComp function is equivalent to the
- LineVDotVPattern function except that the dot patterns are
- encoded in a compressed manner using the M.H. Run Length Code.
- A.3.15.3 Field dot pattern
- Field-Dot-Pattern ::= SEQUENCE { xy-origin-point-coordinate
- Abs-Coord,
- dx-dy-field-dimensions Rel-Coord,
- dot-pattern-data-fdp BITSTRING }
- -- The Field-Dot-Pattern function is equivalent to the
- Line-Dot-Pattern function except that this function defines
- the dot pattern in a rectangular area.
- A.3.15.4 Colouring block
- Colouring-Block ::= SEQUENCE {
- fg-bg-da-existence-indicator INTEGER,
- y-origin-point-coordinate-cb Abs-Coord,
- SEQUENCE OF { SEQUENCE {
- fg-colour BITSTRING,
- bg-colour BITSTRING,
- display-attributes-cb BITSTRING } } }
- -- The Colouring-Block function defines a photographic image by
- specifying the foregroung colour (FG), backgroung colour (BG),
- and display attributes of certain blocks ahead of which is
- indicated by the parameter y-origin-point-coordinate.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- Fascicle VII.5 - Rec. T.101 PAGE45
-
- A.3.15.5 Colouring block comp
- Colouring-Block-Comp ::= SEQUENCE {
- colouring-block-comp-function-id INTEGER,
- fg-bg-da-existence-indicator-cbc INTEGER,
- y-origin-point-coordinate-cbs Abs-Coord,
- SEQUENCE OF { SEQUENCE {
- fg-comp-colour BITSTRING,
- fg-runlength BITSTRING,
- bg-comp-colour BITSTRING,
- bg-runlength BITSTRING,
- display-attributes-cbc BITSTRING,
- da-runlength BITSTRING } } }
- -- The Colouring-Block-Comp function is equivalent to that of the
- Colouring-Block function except that colour and display
- attributes data are encoded by compressed manner as run-length
- code.
- A.3.15.6 Field colouring block
- Field-Colouring-Block ::= SEQUENCE {
- field-colouring-block-function-id INTEGER,
- fg-bg-da-existence-indicator-fcb INTEGER,
- xy-origin-point-coordinate-fcb Abs-Coord,
- dx-dy-field-dimensions-fcb Rel-Coord,
- SEQUENCE OF { SEQUENCE {
- fg-colour-fbc BITSTRING,
- bg-colour-fbc BITSTRING,
- display-attributes-fcb BITSTRING } } }
- -- The Field-Colouring-Block function defines a photographic
- image by specifying the foregroung colour (FG), backgroung
- colour (BG), and display attributes of certain blocks which
- are contained in the the field allocated by
- xy-origin-point-coordinate and the dx-dy-field-dimensions.
- A.3.15.7 Field colouring block comp
- Field-Colouring-Block-Comp ::= SEQUENCE {
- field-colouring-block-comp-function-id INTEGER,
- fg-bg-da-existence-indicator-fcbc
- INTEGER,
- xy-origin-point-coordinate-fcbc
- Abs-Coord,
- dx-dy-field-dimensions-fcbc
- Rel-Coord,
- SEQUENCE OF { SEQUENCE {
- fg-colour-fcbc BITSTRING,
- fg-runlength-fcbc BITSTRING,
- bg-comp-colour-fcbc BITSTRING,
- bg-runlength-fcbc BITSTRING,
- display-attributes-fbc BITSTRING,
- da-runlength-fcbc BITSTRING } } }
- -- The Field-Colouring-Block-Comp function is equivalent to that
- of the Field-Colouring-Block function except that colour and
- display attributes data are encoded by compressed manner as
- run-length code.
- A.3.15.8 Free format colouring block
- Free-Format-Colouring-Block ::= SEQUENCE {
- fg-bg-da-existence-indicator-ffcb INTEGER,
- fg-bg-da-code-length INTEGER,
- run-length-code-length-ffcb INTEGER,
- xy-origin-point-coordinate-ffcb
- Abs-Coord,
- dx-dy-field-dimensions-ffcb
- Rel-Coord,
- SEQUENCE OF { SEQUENCE {
- fg-colour-ffcb BITSTRING,
- runlength-ffcb BITSTRING,
- bg-comp-colour-ffcb BITSTRING,
- bg-runlength-ffcb BITSTRING,
-
-
-
-
- PAGE50 Fascicle VII.5 - Rec. T.101
-
- display-attributes-ffcb BITSTRING,
- da-runlength-ffcb BITSTRING } } }
- -- The Free-Format-Colouring-Block function is equivalent to that
- of the Field-Colouring-Block-Comp function except that the
- code length of the Foreground, Background, Display Attributes
- and Run Lenght can be arbitrarily set.
- A.3.16 Photo graphic string natural image
- Photo-Graphic-String-Natural-Image ::= CHOICE { [0] IMPLICIT
- Header,
- [1] IMPLICIT Transfer,
- [2] IMPLICIT Table-Header,
- [3] IMPLICIT Table-Transfer }
- Header ::= SET { [0] IMPLICIT Components OPTIONAL,
- CHOICE { [1] IMPLICIT Resolution OPTIONAL,
- [2] IMPLICIT PixelPair OPTIONAL }
- [3] IMPLICIT BitsPerDisplay OPTIONAL,
- [4] IMPLICIT SamplingStructure OPTIONAL,
- CHOICE { [5] IMPLICIT Adpcm OPTIONAL,
- [6] IMPLICIT Adct OPTIONAL } }
- Components ::= INTEGER { colorYU*V* (0),
- monochrome (1) }
- Resolution ::= INTEGER { 4-2-2 (0),
- 2-1-1 (1) }
- PixelPair ::= SEQUENCE { PixHor, PixVer }
- PixHor ::= INTEGER
- -- Number of horizontal pixels.
- PixVer ::= INTEGER
- -- Number of vertical pixels.
- BitsPerDisplay ::= SEQUENCE OF INTEGER { 8 bits/pixel
- (0),
- 1 bit/pixel (1),
- 2 bits/pixel (2),
- . . . 9 bits/pixel (9),. .
- . }
- -- One value per component, gives the number or grey or colours a
- pixel may have.
- SamplingStructure ::= SEQUENCE {
- spatial ::= SEQ { INTEGER { line and orthogonal
- (0),
- line and orthogonal field quincunx
- (1),
- line quincunx field orthogonal
- (2),
- line orthogonal single field (3),
- line quincunx single field
- (4) }
- temporal ::= SEQ { INTEGER { coincident (0),
- alternate samples (1),
- sequential line (2) } }
- Adpcm ::= SEQUENCE { INTEGER { Type dpcm (1) },
- INTEGER { Subtype 1 dimension (0) } }
- Adct ::= SEQUENCE { INTEGER { Type transform
- (2) },
- INTEGER { Subtype Cosine (1) },
- INTEGER { Subtype 2 dimension (0) } }
- Transfer ::= SET { Origin, Area, Data }
- Origin ::= CHOICE { [0] IMPLICIT PixelPair OPTIONAL
- Area ::= CHOICE { [1] IMPLICIT PixelPair OPTIONAL
- Data ::= CHOICE { [2] IMPLICIT OCTETSTRING OPTIONAL,
- -- Any value from 4/0 to 7/F.
- [3] IMPLICIT OCTETSTRING OPTIONAL }
- -- Transparent mode 8 bit/octet.
- TableHeader ::= SET { TableSet, TableSize }
- TableSet ::= [0] IMPLICIT SEQUENCE { type ::= INTEGER,
- number ::= INTEGER }
-
-
-
-
- Fascicle VII.5 - Rec. T.101 PAGE45
-
- TableSize ::= [1] IMPLICIT SEQUENCE { depth ::= INTEGER,
- heigth ::= INTEGER,
- width ::= INTEGER OPTIONAL }
- TableTransfer ::= SET { TableSet, Position, Data }
- Position ::= TableSize
- A.3.17 Macro
- A Macro capability is available within the syntax of two of
- the three terminal data syntaxes. This capability permits strings
- of presentation data to be grouped together, so that it may be
- executed by the reference to a single command. In essence both
- terminal data syntax DS I and DS III provide the same Macro
- capability; however, a Macro in one data syntax cannot in general
- be converted to a Macro in another data syntax. This is because a
- Macro may contain any string of presentation data. Since the
- Terminal Models of the various data syntaxes differ, it is often
- necessary to sort the commands in the data stream in order to
- achieve the intended presentation effect. The arbitrary grouping of
- information into Macros prevents general sorting. Since the purpose
- of regular Macro functions are to achieve communications efficiency
- by eliminating the communication of repetitious code, it is
- possible to expand Macros in the conversion process. The conversion
- of a Macro is therefore the string of presentation data which it
- represents.
- Two special forms of Macros in data syntax Ds I and DS III are
- Key Activated Macros and Transit Macros. Key Activated Macros link
- the execution of the Macro function to a local Key on the terminal.
- Since this operation depends upon the interaction of the user, the
- contents of the Macro cannot be expanded in the converter ahead of
- time. The converter must re-transmit the entire page of information
- to the terminal with the contents of the Key Activated Macro sorted
- and factored into the page. This problem must be handled by the
- Interworking Presentation Architecture. Similarly Transit Macro
- provides a problem in conversion. The contents of a Transit Macro
- must be sent back to the source upon a user interaction. In
- interworking this could mean that data syntax DS I data might be
- contained within a Transit Macro in a data syntax DS III terminal
- after a conversion so that it might be sent back to the source
- unchanged. It is necessary to be able to identify entire coding
- environments or to identify uniquely each code table in each Data
- Syntax in order to avoid confusion.
- MACRO-String ::= CHOICE { [1] Define-Macro,
- [2] Define-and-Execute-Macro,
- [3] Define-Transmit-Macro,
- [4] Define-End-of-Macro-Definition,
- [5] Macro-Invocation }
- -- Key Activated Macros are Macros with reference numbers 0 to 7
- in data syntax DS III.
- A.3.17.1 Define macro
- Define-Macro ::= SEQUENCE { SID, INTEGER }
- -- General control character (DEF MACRO) from Recommendation
- T.101 DS III [C1 set position 4/0, (8/0)] and (P-DEF MACRO)
- from DS I [C1 set position 5/5, (9/5) followed by parameter
- 4/0].
- -- Integer number from 0 to 95 correspondig to the Macro
- reference number of the Macro being defined.
- A.3.17.2 Define and execute macro
- Define-and-Execute-Macro ::= SEQUENCE { SID, INTEGER }
- -- General control character (DEFP MACRO) from Recommendation
- T.101 DS III [C1 set position 4/1, (8/1)] and (P-DEFP MACRO)
- from DS I [C1 set position 5/5, (9/5) followed by parameter
- 4/1].
- -- Integer number from 0 to 95 correspondig to the Macro
- reference number of the Macro being defined.
- A.3.17.3 Define transit macro
- Define-Transmit-Macro ::= SEQUENCE { SID, INTEGER }
-
-
-
-
- PAGE50 Fascicle VII.5 - Rec. T.101
-
- -- General control character (DEFT MACRO) from Recommendation
- T.101 DS III [C1 set position 4/2, (8/2)] and (P-DEFT MACRO)
- from DS I [C1 set position 5/5, (9/5) followed by parameter
- 4/2].
- -- Integer number from 0 to 95 correspondig to the Macro
- reference number of the Macro being defined.
- A.3.17.4 Define end-of-macro definition
- Define-End-of-Macro-Definition ::= SID
- -- General control character [END (Macro)] from Recommendation
- T.101 DS III [C1 set position 4/5, (8/5)] and (END MACRO) from
- DS I [C1 set position 5/5, (9/5) followed by parameter 4/15].
- A.3.17.5 Macro invocation
- Macro-Invocation ::= INTEGER
- -- Integer number from 0 to 95 correspondig to the Macro
- reference number of the Macro being invoked.
- -- Note - Macros may invoke other Macros at any time and to any
- depth.
- A.3.18 DRCS string
- The Dynamically Redefinable Character Set (DRCS) capability
- allows additional text or mosaic characters to be defined and used
- as regular alphanumeric text or mosaics. All three of the terminal
- data syntaxes include a form of DRCS capability; however, the
- operation of DRCS is quite different in the various Display
- Environments. In general it is not possible to convert exactly from
- one type of DRCS to another because of the boundary conditions
- imposed by each of the Terminal Data Syntaxes. Different limits
- exist on the number of DRCS characters which may be defined or the
- amount of memory which may be used to store DRCS characters. The
- definition of DRCS characters is a particular difficulty. One of
- the source terminal data syntaxes takes the approach of allowing
- any presentation information to be used in the definition of a DRCS
- character, including geometric drawing commands, bit (photographic)
- and text and even other DRCS characters. The other two source data
- syntaxes define DRCS characters using a bit oriented (photographic)
- approach. Even the two photographic approaches to the definition of
- DRCS are not equivalent since they have different pixel densities
- and serious quantization errors may result from mapping an array of
- pixels to another array of a different size. Three forms of DRCS
- definition are included in the Interworking Data Syntax to
- accommodate the requirements of the three source data syntaxes. The
- conversion process would therefore have sufficient information to
- make the best conversion possible.
- DRCS-String ::= CHOICE { [1] Define-DRCS-Type-I-1byte,
- [2] Define-DRCS-Type-I-2byte,
- [3] Define-DRCS-Type-II,
- [4] Define-DRCS-Type-III,
- [5] End-of-DRCS-Definition-Type-III,
- [6] DRCS-Invocation,
- [7] DRCS-Invocation-2byte }
- A.3.18.1 Define DRCS Type-I 1 byte
- Define-DRCS-Type-I-1byte ::= SEQUENCE { DRCS-I-Char-Size,
- DRCS-I-Code,
- DRCS-I-Data }
- DRCS-I-Char-Size ::= INTEGER { normal-size
- (1),
- medium-size (2),
- small-size (3) }
- DRCS-I-Code ::= INTEGER
- -- Integer number from 0 to 95 correspondig to the DRCS reference
- number of the 1 byte DRCS being invoked.
- DRCS-I-Data ::= BITSTRING
- A.3.18.2 Define DRCS Type-I 2 byte
- Define-DRCS-Type-I-2byte ::= SEQUENCE { DRCS-I-Char-Size,
- DRCS-I-Code,
- DRCS-I-Data }
-
-
-
-
- Fascicle VII.5 - Rec. T.101 PAGE45
-
- -- This structure is the same as "Define-DRCS-Type-I-1byte"
- except that "DRCS-I-Code" is an integer number from 0 to 8835
- correspondig to the DRCS reference number of the 2-byte DRCS
- being invoked.
- A.3.18.3 Define DRCS Type-II
- Define-DRCS-Type-II ::= SEQUENCE { [1] IMPLICIT
- DRCS-Header OPTIONAL,
- -- Description of general properties of the DRCS to be loaded. It
- is applied for all subsequent DRCS-pattern transfer units.
- [2] IMPLICIT DRCS-Pattern OPTIONAL }
- -- Actual pattern data.
- DRCS-Header ::= SEQUENCE { Identification-of-Char-Set,
- Select-Dot-Composition }
- Identification-of-Char-Set ::= SEQUENCE { repertory-info SET {
- repertory-# INTEGER { first
- repertory (1),
- second repertory
- (2) },
- delete-existing-drcs BOOLEAN
- Identification-of-Char-Set ::= SEQUENCE { registration-info
- CHOICE {
- iso-registration [1] IMPLICIT
- GRAPHICSTRING,
- private-drcs-# [2] IMPLICIT
- INTEGER } }
- Select-Dot-Composition ::= SEQUENCE { Character-Cell-Structure,
- Blocking-Factor,
- Pixel-Characteristics }
- Character-Cell-Structure ::= CHOICE { matrix-dimensions
- [1] IMPLICIT SEQUENCE {
- horizontal INTEGER,
- vertical INTEGER },
- -- According to SDC Type 1.
- predefined-matrices [2] IMPLICIT INTEGER {
- n16*24 (0),
- n16*20 (1),
- n16*12 (2),
- n16*10 (3),
- n12*24 (4),
- n12*20 (5),
- n12*12 (6),
- n12*10 (7),
- n8*12 (8),
- n8*10 (9),
- n6*12 (10),
- n6*10 (11),
- n6*5 (12),
- n4*10 (13),
- n4*5 (14),
- n6*6 (15) } }
- -- According to SDC Type-2.
- Blocking-Factor ::= SEQUENCE { horizontal INTEGER,
- vertical INTEGER }
- -- Grouping of character cells, which are considered as a single
- character cell during character description.
- Pixel-Characteristics ::= CHOICE { number of bits [1] IMPLICIT
- INTEGER,
- predefined-numbers [2] IMPLICIT INTEGER }
- basic-DRCS (1),
- -- 1 bit/dot.
- four-colour-DRCS (4),
- -- Black, red, green, yellow from `Basic-Colour-Selection`.
- eight-colour-DRCS (8),
- -- First 8 colours from `Basic-Colour-Selection`.
- sixteen-colour-DRCS (16) }
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- -- 16 redefinable colours.
- -- This data type describes the pattern for the characters of the
- down-loaded DRCS, according the last transmitted header unit.
- It contains no compression for the pattern data. Data Syntax I
- and III have no similar encodings and this method can be used
- for an adequate mapping. All encoding different from the
- direct method and the codes for improvement of the efficiency
- (S-bytes) have to be transformed to the following description.
- DRCS-Pattern ::= SEQUENCE { first character GRAPHICSTRING,
- -- Code of the first character or character block
- pattern-units SEQUENCE OF {
- pattern-block-# SEQUENCE OF INTEGER,
- pattern-block BIT STRING } }
- -- Each pattern block contains one bit of each of the dots,
- starting from the top left hand corner, running row by row
- from left to right. The pattern block numbers are ordered from
- the least significant bit on. If the pattern block is preceded
- by two or more block numbers, the pattern block is applied to
- all of them. The block numbers are in the range of 0 to
- `pixel-characteristics`-1. The length of the pattern block
- equals to the number of pixels in the block.
- A.3.18.4 Define DRCS Type-III
- Define-DRCS-Type-III ::= INTEGER
- -- A function from Recommendation T.101 DS III [C1 set position
- 4/3, (8/3)].
- -- Integer number from 0 to 95 correspondig to the DRCS reference
- number of the DRCS character being defined to be followed by
- data string.
- A.3.18.5 End-of-DRCS definition Type-III
- End-of-DRCS-Definition-Type-III ::= GRAPHICSTRING
- -- General control character [END (DRCS)] from Recommendation
- T.101 DS III [C1 set position 4/5, (8/5)].
- A.3.18.6 DRCS invocation
- DRCS-Invocation ::= INTEGER
- -- Integer number from 0 to 95 correspondig to the DRCS reference
- number of the DRCS being invoked.
- A.3.18.7 DRCS invocation 2 byte
- DRCS-Invocation-2byte ::= INTEGER
- -- Integer number from 0 to 8835 correspondig to the DRCS
- reference number of the 2-byte DRCS being invoked.
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- A.3.19 Fill pattern control string
- The capability to fill a geometrically defined area with an
- arbitrary Fill Pattern, interior style, hatch or texture, is
- provided in two of the source videotex data syntaxes. Since one of
- the terminal Videotex data syntaxes, data syntax DS I, does not
- provide this capability it must be accommodated in the conversion
- process by assigning distinguishing colours or other means to
- indicate the difference between patterned areas. The method by
- which this capability is supported in the other two source data
- syntaxes is quite different. Data syntax DS III provides four
- predefined texture patterns, including solid fill, and four
- redefinable texture masks. These masks are rectilinear and are
- referenced to the origin of the normalized display area. This means
- that abutting areas filled with the same pattern will align
- perfectly. In Interior style patterns defined in data syntax DS II,
- the pattern may be defined on a parallelogram shaped area and is
- referenced to the origin of the area. Data syntax DS II also
- provides eight predefined fill patterns (hatch patterns). In
- general, any texture of interior style pattern may be simulated in
- the conversion process; however, secondary effects such as exact
- alignment of patterns cannot be guaranteed. Texture patterns in
- data syntax DS III are defined by including any string of
- presentation data in the definition of the pattern whereas interior
- styles defined in data syntax DS II are defined in terms of a cell
- array. The conversion process must resolve the pattern before the
- conversion. Limits to global variables, such as the available
- amount of texture memory, is defined by the boundary value
- condition indicators in the state vector.
- Fill-Pattern-Control-String ::= CHOICE { [1] Define-Texture,
- [2] End-of-Texture-Definition,
- [3] Texture-Mask-Size,
- [4] Set-Pattern-Representation,
- [5] Pattern-Selection }
- A.3.19.1 Define texture
- Define-Texture ::= INTEGER
- -- A function from Recommendation T.101 DS III [C1 set position
- 4/4, (8/4)].
- -- Integer number from 4 to 7 correspondig to the redefinable
- Texture Mask to be defined. Note texture masks 0 to 3 are
- predefined and cannot be redefined to be followed by data
- string.
- A.3.19.2 End-of-texture definition
- End-of-Texture-Definition ::= GRAPHICSTRING
- -- General control character [END (TEXTURE)] from Recommendation
- T.101 DS III [C1 set position 4/5, (8/5)].
- A.3.19.3 Texture mask size
- Texture-Mask-Size ::= Rel-Coord
- -- Establish the texture mask size up to the limit defined by the
- boundary conditions.
- -- A function from Recommendation T.101 DS III [C1 set position
- 2/3, (10/3)].
- A.3.19.4 Set pattern representation
- Set-Pattern-Representation ::= SEQUENCE { pattern-index INTEGER,
- -- This number corresponds to the current pattern definition. It
- can be referenced by subsequent fill area style indices.
- delta-x INTEGER,
- delta-y INTEGER,
- -- A grid of delta-x* delta-y* cells is specified. The colour of
- each cell is individually given by the
- pattern-cell-data Pixel-Array-Data }
- -- The colour array is associated with the cells as follows: the
- element (1, delta-y) is associated with the cell having the
- pattern reference point at one corner. Elements with
- increasing first dimension are associated with succesive cells
- in the direction of the pattern with vector; elements with
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- decreasing second dimension are associated with succesive
- cells in the direction of the pattern height vector.
- -- These definitions of patterns are from DS II and are
- applicable in conjugation with the fill area attributes
- defined by the data type "Display-Element-Attributes".
- A.3.19.5 Pattern selection
- Pattern-Selection ::= INTEGER
- -- Integer number from 4 to 7 correspondig to the Texture Mask
- being selected.
- A.3.20 Music string
- The music capability is an option unique to only one of the
- terminal data syntaxes. It requires special capabilities for
- presentation and cannot be converted in any reasonable manner.
- Music information is included in the Interworking Data Syntax for
- future compatibility so that interworking may be accomplished
- between information from data syntax DS I and any future versions
- of data syntax DS II or III which might include a music capability.
- Music-String ::= CHOICE { [1] Music-Code-Sequence,
- [2] Music-Control-Sequence }
- A.3.20.1 Music code sequence
- Music-Code-Sequence ::= GRAPHICSTRING
- -- Characters from Recommendation T.101 DS I [Musical Tone Set
- (pitch/duration)]. Note that the Musical Tone set is a two
- byte set which can be described as the combination of two one
- byte sets, one for duration and one for pitch. Reference is
- made to Recommendation T.101 since this code table has not yet
- been registered.
- A.3.20.2 Music code sequence
- Music-Control-Sequence ::= GRAPHICSTRING
- -- Control characters from Recommendation T.101 DS I (Musical
- Control C1 Set). The Musical Control set contains the
- functions: Start Music Sequence, End Music Sequence, Start
- Melody Part, Start Rythm Part, End Part, Music Label, Jump to
- Part, Music Repeat, Music Branch, Sound Level, Change of
- Timbre, Long Duration Rest or Tone. Reference is made to
- Recommendation T.101 since this code table has not yet been
- registered.
- A.3.21 Telesoftware string
- Telesoftware-String ::= Further Study
- A.3.22 Audio data string
- Audio-Data-String ::= Further Study
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