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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) }
PAGE50 Fascicle VII.5 - Rec. T.101
-- 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.
Fascicle VII.5 - Rec. T.101 PAGE45
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
PAGE50 Fascicle VII.5 - Rec. T.101
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
Fascicle VII.5 - Rec. T.101 PAGE45