SIST ETS 300 174 E1:2003
(Main)Network Aspects (NA); Digital coding of component television signals for contribution quality applications in the range 34 - 45 Mbit/s
Network Aspects (NA); Digital coding of component television signals for contribution quality applications in the range 34 - 45 Mbit/s
.
Omrežni vidiki (NA) – Digitalno kodiranje komponent televizijskih signalov za aplikacije z dodano kakovostjo v območju 34–45 Mbit/s
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2003
2PUHåQLYLGLNL 1$ ±'LJLWDOQRNRGLUDQMHNRPSRQHQWWHOHYL]LMVNLKVLJQDORY]D
DSOLNDFLMH]GRGDQRNDNRYRVWMRYREPRþMX±0ELWV
Network Aspects (NA); Digital coding of component television signals for contribution
quality applications in the range 34 - 45 Mbit/s
Ta slovenski standard je istoveten z: ETS 300 174 Edition 1
ICS:
33.160.25 Televizijski sprejemniki Television receivers
35.040 Nabori znakov in kodiranje Character sets and
informacij information coding
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN ETS 300 174
TELECOMMUNICATION November 1992
STANDARD
Source: ETSI TC-NA Reference: DE/NA-0001*
ICS: 33.080
Coding, TV
Key words:
Network Aspects (NA);
Digital coding of component television signals
for contribution quality applications
in the range 34 - 45 Mbit/s
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
F-06921 Sophia Antipolis CEDEX - FRANCE
Postal address:
650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
Office address:
c=fr, a=atlas, p=etsi, s=secretariat - secretariat@etsi.fr
X.400: Internet:
Tel.: +33 92 94 42 00 - Fax: +33 93 65 47 16
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1992. All rights reserved.
New presentation - see History box
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ETS 300 174: November 1992
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.
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ETS 300 174: November 1992
Contents
Foreword.7
1 Scope .9
2 Normative references .9
3 Definitions, symbols and abbreviations .10
3.1 Arithmetic operators.10
3.2 Relational operators.10
3.3 General abbreviations and usage .11
4 Summary specification of component tv codecs for 34 - 45 Mbit/s.13
5 Video coding and DCT transformation.14
5.1 Coding modes.14
5.1.1 Intra-field mode. 14
5.1.2 Inter-field and inter-frame mode .15
5.1.3 Definition of the different modules.15
5.1.4 Notation. 16
5.1.5 Mode choice .16
5.2 Discrete cosine transform .17
5.3 Prediction of the block.17
5.3.1 Inter-field mode. 17
5.3.2 Inter-frame mode . 18
5.3.3 Video level outside active picture .18
5.4 Motion compensation. 19
6 Quantisation of DCT coefficients.19
6.1 AC coefficient quantisation.20
6.1.1 Computation of relative coefficients.20
6.1.2 Quantisation of relative coefficients.20
6.1.2.1 Quantisation characteristic .20
6.1.2.2 Determination of transmission threshold matrix.20
6.1.2.3 Data accuracy. 21
6.1.2.4 Ranges of quantisation parameters.21
6.2 DC-coefficient quantisation.24
6.3 Inverse quantisation.24
7 Variable length coding for DCT coefficients and motion vector differences .25
7.1 Scanning path for quantised DCT values .25
7.2 Assignment of codewords to quantised values and run lengths.25
7.3 Coding of the motion vectors.28
8 Video framing and forward error correction .30
8.1 Video framing .30
8.1.1 General structure .30
8.1.2 Detailed content.30
8.1.3 Definition of the data for phase information and status in the video
multiplex .32
8.1.4 Generation of the EOB sequence .32
8.2 Forward error protection and correction.33
9 Additional services.34
9.1 Audio .34
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ETS 300 174: November 1992
9.2 Supervision channel.34
9.2.1 Overview .34
9.2.2 Message definition.35
9.2.2.1 Alarms (mandatory, address FE hex, priority 3) .35
9.2.2.2 Multiplex structure (mandatory, address FD hex, priority
2) .36
9.2.2.3 Source identification (optional, address FC hex, priority 2) .36
9.2.2.4 Destination identification (optional, address FB hex,
priority 2) .36
9.2.2.5 Identification of the encoder (optional, address FA hex,
priority 2) .36
9.2.2.6 Other messages.37
9.2.2.7 Header.37
9.2.3 Packet structure.37
9.2.4 Frame structure.37
9.2.5 Channel management .38
9.2.6 Extension rules.38
9.3 Transmission frame for teletext and other digital data inserted during field blanking
intervals.38
9.3.1 Introduction.38
9.3.2 Frame structure.39
9.3.3 Data field allocation .40
9.3.4 Teletext messages .40
9.3.5 EBU Tech 3217 data .41
9.4 Transmission format of test lines in a 128 kbit/s channel.41
9.4.1 Introduction.41
9.4.2 Sampling of the testlines .41
9.4.3 Format .42
9.5 Transmission of 80-bit serial time code in a dedicated 8 kHz channel.42
10 Service multiplex.43
10.1 Introduction.43
10.2 TV container .44
10.2.1 General structure .44
10.2.2 Column allocation .44
10.2.3 Definitions.44
10.2.4 34 and 45 Mbit/s interworking.47
11 Network adaptation .48
11.1 Network adaptation to 34 368 kbit/s CCITT Recommendation G.751 frame.48
11.2 Network adaptation of 686 octet containers to 44 736 kbit/s CCITT Recommendation
G.752 frame .50
11.3 Network adaptation to SDH.51
12 Scrambling for conditional access of transmitted data .51
12.1 General description of the access control system .51
12.2 The pseudo-random generator .54
12.2.1 Introduction.54
12.2.2 Description.54
12.3 PRG initialisation parameters .56
12.3.1 CIW generator .56
12.3.2 Control word .57
12.3.3 Synchronisation .58
12.4 Performance of the PRG .58
12.4.1 Periodicity of sequences .58
12.4.2 Degenerations.58
12.5 Generating scrambling sequences with the PRG.59
12.6 Conditional access system.60
12.7 Interface between codec and access control system .61
12.7.1 Interface signals.61
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ETS 300 174: November 1992
12.7.2 Electrical and physical interface. 61
12.7.3 Encryption modes.62
12.7.4 Format of the CWs and configuration messages.62
Annex A (informative): Recommended features .64
A.1 Introduction.64
A.2 Mode choice.64
A.3 Refresh strategy .64
A.4 Motion estimation.64
A.5 Truncation or rounding of coefficients.64
A.6 Buffer regulation.64
A.7 Criticality .65
A.8 Error concealment.65
A.9 Transmission of PAL signals.65
Annex B (informative): Transmission of composite signals using the component tv codec .66
B.1 Introduction.66
B.2 PAL and NTSC.66
B.2.1 Complementary decoding .66
B.2.2 Choice of decoding technique.67
B.3 SECAM. 67
Annex C (informative): Access control management .68
C.1 Introduction.68
C.2 Message format.68
C.3 Control words transfer using ECM.70
C.3.1 Description of Entitlement Control Messages (ECM).70
C.3.1.1 Command Identifier (CI). 70
C.3.1.2 Command Length Indicator (CLI).70
C.3.1.3 Parameter Identifier (PI). 70
C.3.1.4 List of parameters available in ECM messages.71
C.3.1.5 Programme Provider Identifier (PPID).72
C.3.1.6 Broadcast date CDATE + Theme/Level THEME/LEVEL .72
C.3.1.7 Broadcast date CDATE + Programme class LINK .73
C.3.1.8 Programme Number (PNUMB) .74
C.3.1.9 Programme Number (PNUMB) and Programme cost (PPV/P).74
C.3.1.10 Programme Number (PNUMB) + Cost per time unit PPV/T .74
C.3.1.11 Even Control Word cryptogram (ECW) . 75
C.3.1.12 Odd Control Word cryptogram (OCW).75
C.3.1.13 Odd and Even Control Word cryptograms (ECW/OCW).76
C.3.1.14 HASH signature.76
C.3.2 Description of ECM messages with examples .76
C.3.2.1 Subscription per theme/level.76
C.3.2.2 Impulse pay-per-view per programme.77
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ETS 300 174: November 1992
Annex D (informative): Network adaptation to SDH VC-2 5C.78
History .79
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ETS 300 174: November 1992
Foreword
This European Telecommunication Standard (ETS) has been prepared by the Network Aspects (NA)
Technical Committee of the European Telecommunications Standards Institute (ETSI).
The draft was agreed by a coding experts group including personnel from the European Broadcasting
Union (EBU) and approved by the ETSI NA Technical Committee.
The draft was then approved under the ETSI Accelerated approval Procedure No. 3 (AP 3). However, due
to technical improvements and reasons of compatibility with CCITT "CCIR Joint Study Group" - CMTT/2
work, alterations were submitted for National Voting using ETSI Vote No. 26. The nationally agreed
changes are incorporated into this ETS.
The draft constitutes a common standard for the coding and transmission of television signals in the range
of 34 - 45 Mbit/s, in the format specified by CCIR Recommendation 601 [1], and is in line with other
relevant CCIR and CCITT Recommendations as referenced.
Annexes A, B, C and D are informative.
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ETS 300 174: November 1992
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ETS 300 174: November 1992
1 Scope
This European Telecommunication Standard (ETS) constitutes a common standard for the coding and
transmission of component television signals at bit-rates in the range of 34 - 45 Mbit/s in the format
specified by CCIR Recommendation 601 [1]. The standard embraces the coding algorithm needed for
digital picture coding at about 34 and 45 Mbit/s, and their interfaces with the transmission network. The
video coding algorithms are based on a hybrid predictive/transform scheme incorporating arrangements for
Variable word-Length Coding (VLC), synchronisation and video framing. Provision is made for the
transmission of audio and teletext services to accompany the video and for the application of scrambling
for conditional access.
Network adaptation is specified to both plesiochronous and synchronous digital hierarchies.
2 Normative references
This ETS incorporates, by dated or undated reference, provisions from other publications. These normative
references are cited at the appropriate places in the text and the publications are listed hereafter. For
dated references subsequent amendments to, or revisions of any of these publications apply to this ETS
only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies.
[1] CCIR Recommendation 601: "Encoding Parameters of Digital Television for
Studios".
[2] CCITT Recommendation G.751 (1988): "Digital multiplex equipments operating
at the third order bit rate of 34 368 kbit/s and the fourth order bit rate of 139 264
kbit/s and using positive justification".
[3] CCITT Recommendation G.752 (1988): "Characteristics of digital multiplex
equipments based on a second order bit rate of 6312 kbit/s and using positive
justification".
[4] CCITT Recommendation G.707 (1988): "Synchronous digital hierarchy bit rates".
[5] CCITT Recommendation G.708 (1988): "Network node interface for the
synchronous digital hierarchy".
[6] CCITT Recommendation G.709 (1988): "Synchronous multiplexing structure".
[7] CCITT Recommendation H.261 (1988): "Codec for audiovisual services at n x
384 kbit/s".
[8] CCIR Report 624: "Characteristics of television signals".
[9] EBU Tech. 3250 (1985): "Specification of the digital audio interface" (also exists
as draft AES Recommendation AES 18 - 19xx).
[10] CCIR Recommendation 724: "Transmission of digital studio quality sound signals
over H1 channels".
[11] ISO Standard 3309-2 (1984): "Information processing systems -- Data
communication -- High-level data link control procedures -- Frame structure".
[12] CCIR Recommendation 653: "Teletext systems".
[13] EBU Technical Document 3217 (3rd edition, reissued 1986): "Specification of
insertion data signal equipment for international transmissions".
[14] CCIR Recommendation 656: "Interfaces for digital component video signals in
525-line and 625-line television systems".
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ETS 300 174: November 1992
[15] IEC Publication 461 (1986): "Timecode and control code for video tape
recorders".
[16] CCITT Recommendation V.24 (1988): "List of definitions for interchange circuits
between data terminal equipment (DTE) and data circuit-terminating equipment
(DCE)".
[17] CCITT Recommendation V.28 (1988): "Electrical characteristics for unbalanced
double-current interchange circuits".
[18] ISO Standard 2110 (1980): "Data communication - 25-pin DTE/DCE interface
connector and pin assignments".
[19] CCIR Report 1206: "Methods for picture quality assessments in relation to
impairments from digital coding of television signals".
[20] BBC Research Department Report BBC RD 1986/2; Clarke, C.K.P. (1986):
"Colour encoding and decoding techniques for line-locked sampled PAL and
NTSC television signals".
[21] EBU Technical Statement D29-1980 (1980): "Line identification of the D /D
R B
sequence of SECAM signals".
3 Definitions, symbols and abbreviations
For the purposes of this ETS, the following definitions, symbols and abbreviations apply.
3.1 Arithmetic operators
+ Addition
- Subtraction or negation
* Multiplication
/ Integer division
Σ Summation
LCM Lowest Common Multiple
XOR Exclusive OR binary operation (modulo-2 addition)
3.2 Relational operators
= Equal
≠ Not equal
> Greater than
< Less than
≥ Greater than or equal to
≤ Less than or equal to
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ETS 300 174: November 1992
3.3 General abbreviations and usage
binary A number system with base 2
hexadecimal A number system with base 16. In written form, equivalents of the decimal
numbers 10 to 15 are replaced by the letters A to F
XY hex Values expressed in hexadecimal notation
bit A contraction of the words "binary digit"
word A group or sequence of bits treated together
octet A sequence of 8 bits operated on as a data group or word
MSB Most Significant Bit of a word or octet of bits
LSB Least Significant Bit of a word or octet of bits
Y Luminance signal or sample
R Red chrominance signal
B Blue chrominance signal
C Scaled colour difference signal or sample Y-R
R
C Scaled colour difference signal or sample Y-B
B
PLL Phase Locked Loop
FEC Forward Error Correction
ATM Asynchronous Transfer Mode
SDH Synchronous Digital Hierarchy
PDH Plesiochronous Digital Hierarchy
PAL Acronym for Phase Alternate Line - a composite analogue colour transmission
system
SECAM Acronym for Sequential Colour with Memory - a composite analogue colour
transmission system
NTSC Acronym for the National Television System Committee which developed the
composite analogue colour transmission system that is used in the majority of
countries using 525-line, 60 Hz scanning parameters
MAC Acronym for Multiplexed Analogue Components. An analogue component colour
transmission system. Usually prefixed with letters and/or numbers denoting the
variant
FSW Frame Synchronisation Word
VLC Variable Length (word) Coding
CIW Container Identification Word
CW Control Word
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ETS 300 174: November 1992
ECM Entitlement Control Message
ECW Even Control Word
EMM Entitlement Management Message
PRG Pseudo-Random (sequence) Generator
IW Initialisation Word loaded into pseudo-random sequence generators for
descrambling
OCW Odd Control Word
PPI Phase Parity Identifier indicating which CW must be used for descrambling
Other abbreviations and specialised terminology is noted where it occurs in the document.
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ETS 300 174: November 1992
4 Summary specification of component tv codecs for 34 - 45 Mbit/s
Table 1
�˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¿
‡ VIDEO ‡ Standard ‡ 525-line or 625-line digital video in component ‡
‡INPUT/OUTPUT‡ ‡ form. Manual or automatic selection of the video ‡
‡ ‡ ‡ standard is at the manufacturer’s discretion ‡
‡ ‡ ‡ (see NOTE 1). ‡
‡ ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ Coding ‡ 4:2:2 level of CCIR Recommendation 601 [1]. ‡
‡ ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ Interfaces ‡ Bit-serial (10-bit, 270 Mbit/s serial interface).‡
‡ ‡ ‡ CCIR Recommendation 656 [14] bit-parallel ‡
‡ ‡ ‡ interfaces shall also be provided. ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ SIGNAL ‡ Horizontal ‡ Full digital active line of 720 samples for ‡
‡PREPROCESS- ‡ ‡ luminance (Y) and 360 samples for each colour- ‡
‡ ING ‡ ‡ difference (CR, CB). ‡
‡ ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ Vertical ‡ 525 line : 248 lines per field (see NOTE 2). ‡
‡ ‡ ‡ Field 1 : lines 16 to 263 ‡
‡ ‡ ‡ Field 2 : lines 278 to 525 ‡
‡ ‡ ‡ ‡
‡ ‡ ‡ 625 line : 288 lines per field ‡
‡ ‡ ‡ Field 1 : lines 23 to 310 ‡
‡ ‡ ‡ Field 2 : lines 336 to 623 ‡
‡ ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ Numerical ‡ Digital input samples of Y, CR and CB conform ‡
‡ ‡ represen- ‡ to the CCIR Recommendation 601 [1] numerical ‡
‡ ‡ tation ‡ range. These samples are converted to an 8-bit ‡
‡ ‡ ‡ 2’s complement representation for the purpose of ‡
‡ ‡ ‡ processing within the codec. ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ CODING ‡ Modes ‡ Three modes (intra-field, inter-field and motion ‡
‡ ‡ ‡ compensated inter-frame) are used. The following ‡
‡ ‡ ‡ three processing operations are applied either ‡
‡ ‡ ‡ on 8x8 intra-field blocks (intra-field mode) or ‡
‡ ‡ ‡ on differential blocks obtained by difference ‡
‡ ‡ ‡ between the current 8x8 intra-field block and a ‡
‡ ‡ ‡ reference block taken in the previous field ‡
‡ ‡ ‡ (inter-field mode) or in the field with the same ‡
‡ ‡ ‡ parity in the previous frame (inter-frame mode) ‡
‡ ‡ ‡ (see subclause 5.1). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ DCT ‡ Discrete Cosine Transform applied on rectangular ‡
‡ ‡ ‡ blocks of 8 lines of 8 samples for the three ‡
‡ ‡ ‡ components Y, CR, CB (see subclause 5.2). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ Prediction ‡ For each block processed according to inter˜ ‡
‡ ‡of the block ‡ field mode, the reference block is determined ‡
‡ ‡ ‡ with pixels of the previous field without motion ‡
‡ ‡ ‡ compensation. For each block processed according ‡
‡ ‡ ‡ to interframe mode, the reference block is taken ‡
‡ ‡ ‡ from the position of the current block by ‡
‡ ‡ ‡ application of a displacement vector ‡
‡ ‡ ‡ (see subclause 5.3). ‡
‡ ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ Motion ‡ Motion compensation is applied to "macro-blocks".‡
‡ ‡compensation ‡ Each macro-block (two adjacent 8x8 blocks for Y ‡
‡ ‡ ‡ and the two co-positioned CR and CB blocks) is ‡
‡ ‡ ‡ assigned a single displacement vector with half- ‡
‡ ‡ ‡ pel accuracy (see subclause 5.4). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡Quantisation ‡ A different quantisation characteristic is used ‡
‡ ‡ ‡ for each coefficient. Its parameters are adapted ‡
‡ ‡ ‡ to the buffer occupancy, the type of block ‡
‡ ‡ ‡ (luminance/chrominance), and the criticality of ‡
‡ ‡ ‡ the block. The shape of the characteristic is ‡
‡ ‡ ‡ nearly uniform (see Clause 6). ‡
‡ ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ Variable ‡ VLCs are used to encode the quantised DCT ‡
‡ ‡ length ‡ coefficients and motion information ‡
‡ ‡ coding ‡ (see Clause 7). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡ ‡
(Continued)
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ETS 300 174: November 1992
Table 1 (concluded)
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜´˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¿
‡ BUFFER MEMORY CAPACITY ‡ 1 572 864 bits. ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ VIDEO FRAMING ‡ (See Clause 8). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ VIDEO DATA ERROR ‡ Reed Solomon (255, 239) interleaving factor 6 ‡
‡ PROTECTION ‡ (see subclause 8.2). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ SERVICE MULTIPLEX ‡ (See Clause 10). ‡
‡ ‡ ‡
‡ ‡ This combines: ‡
‡ ‡ ‡
‡ ‡ - a video channel; ‡
‡ ‡ - 2 048 kbit/s (or 1 544 kbit/s) audio channel(s) ‡
‡ ‡ (NOTE 3); ‡
‡ ‡ - 384 kbit/s teletext channel(s) (see subclause 9.3); ‡
‡ ‡ - 128 kbit/s test˜line channel (see subclause 9.4); ‡
‡ ‡ - 8 kbit/s supervision channel (see subclause 9.2); ‡
‡ ‡ - two 8 kbit/s conditional access channels; ‡
‡ ‡ - two 8 kbit/s time code channels (see subclause 9.5). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ NETWORK ADAPTATION ‡ Adaptation to CCITT Recommendations G.751 [2], ‡
‡ ‡ G.752 [3] and to SDH CCITT Recommendations G.707 [4], ‡
‡ ‡ G.708 [5], G.709 [6] ‡
‡ ‡ (see Clause 11 and informative Annex D). ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜¯˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ SCRAMBLING FOR ‡ (See Clause 12 and informative Annex C). ‡
‡ CONDITIONAL ACCESS ‡ ‡
ˆ˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜`˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜·
‡ ‡
‡ NOTE 1: This codec can accommodate the transmission of PAL/SECAM/NTSC by ‡
‡ optional decoders and encoders (see informative Annex B). ‡
‡ ‡
‡ NOTE 2: Only 244 lines per field are significant; lines 16, 17, 18, 19 ‡
‡ and 278, 279, 280, 281 are encoded but not displayed. ‡
‡ ‡
‡ NOTE 3: Neither the coding nor the error protection of the audio channels ‡
‡ is covered by this specification. ‡
‡ ‡
�˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜˜�
5 Video coding and DCT transformation
5.1 Coding modes
Two processing modes are used, intra-field mode, and inter-field and inter-frame mode.
5.1.1 Intra-field mode
�˜˜˜˜¿ �˜˜˜¿ �˜˜˜˜˜˜¿
‡ ‡ ‡ ‡ ‡ ‡
video in ˜˜˜˜˜˜˜˜˜>˜˜˜˜˜˜˜˜>‡DCT ˆ˜˜>˜˜˜‡ Q ˆ˜˜´˜˜>‡CODINGˆ˜>˜ OUTPUT
‡ ‡ ‡ ‡ ‡ ‡ ‡
x=z �˜˜˜˜� X=Z �˜˜˜� ‡ �˜˜˜˜˜˜�
�˜˜˜˜˜˜¿ ‡
‡ ‡ �˜˜˜˜¿ �˜˜˜¿ ‡
‡IMAGE ‡<˜˜˜˜˜·IDCT‡<˜˜˜˜˜·IQ ‡<˜�
‡MEMORY‡ �˜˜˜˜� �˜˜˜�
‡ ‡
�˜˜˜˜˜˜�
Figure 1: Intra-field mode
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ETS 300 174: November 1992
5.1.2 Inter-field and inter-frame mode
Figure 2: Inter-field and inter-frame mode
5.1.3 Definition of the different modules
DCT Discrete Cosine Transformation (for 8x8 blocks).
IDCT Inverse DCT (for 8x8 blocks).
Q Quantisation (see Clause 6).
IQ The IQ module builds a DCT-coefficients block from the corresponding
transmitted information, by assigning to the coefficients the reconstruction values
corresponding to the transmitted quantisation levels (see Clause 6).
Coding (See Clause 7).
Image Memory Provides storage for:
- the decoded current field. This field is used as reference for coding the
next image;
- the two last previously decoded fields, which are used to determine the
current reference block.
For the inter-field mode
The reference block is computed with pixels of the previous field according
to the interpolation process described in subclause 5.3.
For the inter-frame mode
The reference block is taken in the field of the previous frame with the
same parity as the current field. Its position is obtained from the position
of the current block by a translation given by a motion vector. The
specification of the motion vector is given in subclause 5.4, the exact
computation of the reference block for the inter-frame mode is presented
in subclause 5.3.
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ETS 300 174: November 1992
5.1.4 Notation
x(i,j) 8x8 pixels block.
xp(i,j) 8x8 reference block.
z(i,j) = x(i,j) for the intra-field mode.
= x(i,j) - xp(i,j) for the inter-frame or inter-field mode.
X(k,l) The 8x8 DCT coefficients block in intra-field mode.
Y(k,l) The 8x8 DCT coefficients block in inter-frame or inter-field mode.
Z(k,l) = X(k,l) for intra-field mode.
= Y(k,l) for inter-frame or inter-field mode.
(i,j) Coordinates in the image domain:
i is the line index (range: 0 to 7 from left to right);
j is the column index (range: 0 to 7 from top to bottom).
(k,l) Coordinates in the transform domain:
k is the line index (range: 0 to 7);
l is the column index (range: 0 to 7).
5.1.5 Mode choice
The chosen mode (intra-field, inter-field or inter-frame) is coded and transmitted for each processed
macro-block (see subclause 8.1). No specification is given for the mode choice as it concerns only the
coder side.
The inter-field and the inter-frame scheme presented in figure 2 allows the use of a priori choice (decision
done before coding steps) or a posteriori choice (decision done after having coded the blocks according to
both modes).
In the inter modes, the z(i,j) elements must be in the range (-128, 127); the mode decision is forced, when
necessary, in order to satisfy this constraint.
To avoid the temporal propagation of transmission error effects it is recommended to use an intra-field
refreshing processing. This processing concerns only the coder and is not specified.
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ETS 300 174: November 1992
5.2 Discrete cosine transform
For each component (Y, C , C ), the discrete cosine transformation is applied to blocks composed of
R B
eight lines of eight samples. The data to be processed are, for each block, the samples of the present
field, or the differences between the present field samples and those obtained from a reference block (see
subclause 5.3). The direct transformation is computed according to the formula:
7 7
1 ππ()21ik++()21j l
Zk(,l)= C C z(i,j)cos cos
kl
∑∑
ij0 0
4 == 16 16
and the inverse transformation is given by:
7 7
1 ππ()21ik++()21jl
Zi(,j)= C C z(k,l)cos cos
kl
∑∑
kl==0 0
4 16 16
with the terms as defined in subclause 5.1:
C==for l0
C==for k0 l
k
=1 = 1
elsewhere elsewhere
Z(0,0) is called the DC coefficient: the other coefficients are AC coefficients.
The input to the DCT is expressed as 2's complement integers of 8 bits (including sign). The output of the
DCT is expressed as 12-bit 2's complement numbers, of which the integer part is 11 bits (including sign).
The accuracy of the performance of the inverse DCT computation is in accordance with that specified in
CCITT Recommendation H.261 [7].
5.3 Prediction of the block
5.3.1 Inter-field mode
The reference block xp for the current block x in field N is computed with pixels of field N-1 with the
following interpolation scheme:
E ˜˜˜˜˜˜˜˜˜˜¿ 8 �˜¿
�˜˜˜˜˜/˜˜˜˜˜>‡ ‡ 9 �˜˜˜˜˜¿ 8
‡+ˆ˜˜˜˜˜/˜˜˜˜>‡shiftˆ˜˜/˜˜˜˜xp
�˜˜˜˜˜/˜˜˜˜˜>‡ ‡ �˜˜˜˜˜�
F ˜˜˜˜˜˜˜˜˜˜� 8 �˜�
E and F are defined below.
˜˜˜˜˜˜˜*˜˜˜˜˜˜*˜˜˜˜˜˜*˜˜˜˜˜˜˜ Field N-1
E
˜˜˜˜˜˜˜*˜˜˜˜˜˜*˜˜˜˜˜˜*˜˜˜˜˜˜˜ Field N
x(i,j)
˜˜˜˜˜˜˜*˜˜˜˜˜˜*˜˜˜˜˜˜*˜˜˜˜˜˜˜ Field N-1
F
Figure 3
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ETS 300 174: November 1992
5.3.2 Inter-frame mode
The position of the reference block is obtained from the position of the currently processed block by a
translation. For motion compensation, the translation vector (x,y) is as described in subclause 5.4.
There is no ambiguity in the definition of the reference block when the coordinates (x,y) are integer. If one
of the coordinates has a non-zero fractional part, an interpolation scheme has to be used to build the
reference block.
This scheme is described below for ½ pel accuracy for luminance and ¼ pel accuracy for colour
difference:
A+ U. P. X. +B
Q. V. R. Y. S.
C+ W. T. Z. +D
A, B, C, D reconstituted pixels of the previous frame (in the field of the same parity). Integer
coordinates.
P, Q, R, S, T, U, interpolated pixels of the previous frame (in the field of the same parity).
V, W, X, Y, Z
The values assigned to interpolated pixels are: P = [(A+B)/2]
Q = [(A+C)/2]
R = [(A+B+C+D)/4]
U = [(3A+B)/4]
V = [(3A+B+3C+D)/8]
as illustrated in figure 4.
A ˜˜˜˜˜˜˜˜˜˜¿ 8 �˜¿
�˜˜˜˜˜/˜˜˜˜˜>‡ ‡ 9 �˜˜˜˜˜¿ 8
‡+ˆ˜˜˜˜/˜˜˜>‡shift‡˜˜/˜> P or Q
�˜˜˜˜˜/˜˜˜˜˜>‡ ‡ �˜˜˜˜˜�
B or C ˜˜˜˜˜˜˜˜˜˜� 8 �˜�
A ˜˜˜˜˜˜¿ 8 �˜¿
�˜˜/˜˜>‡ ‡ 9
‡+ˆ˜˜/˜˜¿
�˜˜/˜˜>‡ ‡ ‡ �˜¿
B ˜˜˜˜˜˜� 8 �˜� �˜˜˜˜˜>‡ ‡ 10 �˜˜˜˜˜˜˜˜¿ 8
‡+ˆ˜˜˜˜/˜˜>‡2 shifts‡˜˜/˜˜> R
C ˜˜˜˜˜˜¿ 8 �˜¿ �˜˜˜˜˜>‡ ‡ �˜˜˜˜˜˜˜˜�
�˜˜/˜˜>‡ ‡ ‡ �˜�
‡+ˆ˜˜/˜˜�
�˜˜/˜˜>‡ ‡ 9
D ˜˜˜˜˜˜� 8 �˜�
3A ˜˜˜˜˜˜˜˜˜˜¿ 10 �˜¿
�˜˜˜˜˜/˜˜˜˜˜>‡ ‡ 10 �˜˜˜˜˜˜˜˜¿ 8
‡+ˆ˜˜˜˜˜/˜˜˜˜>‡2 shifts‡˜˜/˜˜> U
�˜˜˜˜˜/˜˜˜˜˜>‡ ‡ �˜˜˜˜˜˜˜˜�
B ˜˜˜˜˜˜˜˜˜˜� 8 �˜�
3A ˜˜˜˜˜˜¿ 10 �˜¿
�˜˜/˜˜>‡ ‡
‡+‡ 10
�˜˜/˜˜>‡ ‡˜˜/˜˜¿ �˜¿
B ˜˜˜˜˜˜� 8 �˜� �˜˜˜˜˜>‡ ‡ 11 �˜˜˜˜˜˜˜˜¿ 8
‡+‡˜˜/˜˜>‡3 shifts‡˜˜/˜˜> V
3C ˜˜˜˜˜˜¿ 10 �˜¿ �˜˜˜˜˜>‡ ‡ �˜˜˜˜˜˜˜˜�
�˜˜/˜˜>‡ ‡˜˜/˜˜� �˜�
‡+‡ 1
�˜˜/˜˜>‡ ‡
D ˜˜˜˜˜˜� 8 �˜�
Figure 4
5.3.3 Video level outside active picture
In the definition of the reference block given in subclauses 5.3.1 and 5.3.2, the pixels outside the active
picture must be set to zero, expressed in 2's complement (8 bits).
Page 19
ETS 300 174: November 1992
0 0 0 0
�˜˜˜˜˜˜˜˜˜˜¿
0‡ Y ‡0
‡ ‡
0‡CB and CR ‡0
�˜˜˜˜˜˜˜˜˜˜�
0 0 0 0
Figure 5
5.4 Motion compensation
Only one motion vector is used for the blocks belonging to a macro-block. The parameters of the motion
compensation are given in table 2.
Table 2
�˜˜˜
...
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