SIST EN ISO/IEC 11172-1:1997

SLOVENSKI STANDARD
SIST EN ISO/IEC 11172-1:1997
01-december-1997
Information technology - Coding of moving pictures and associated audio for
digital storage media at up to about 1,5 Mbit/s - Part 1: Systems (ISO/IEC 11172-
1:1993)
Information technology - Coding of moving pictures and associated audio for digital
storage media at up to about 1,5 Mbit/s - Part 1: Systems (ISO/IEC 11172-1:1993)
Informationstechnik - Codierung von bewegten Bildern und damit verbundenen
Tonsignalen für digitale Speichermedien bis zu 1,5 Mbit/s - Teil 1: Systeme (ISO/IEC
11172-1:1993)
Technologies de l'information - Codage de l'image animée et du son associé pour les
supports de stockage numérique jusqu'a environ 1,5 Mbit/s - Partie 1: Systemes
(ISO/IEC 11172-1:1993)
Ta slovenski standard je istoveten z: EN ISO/IEC 11172-1:1995
ICS:
35.040 Nabori znakov in kodiranje Character sets and
informacij information coding
SIST EN ISO/IEC 11172-1:1997 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO/IEC 11172-1:1997

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SIST EN ISO/IEC 11172-1:1997

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SIST EN ISO/IEC 11172-1:1997

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SIST EN ISO/IEC 11172-1:1997
INTERNATIONAL ISO/IEC
STANDARD 11172-1
First edition
1993-08-0 1
Information technology - Coding of
moving pictures and associated audio for
digital storage media at up to about
1,5 Mbit/s -
Part 1:
Systems
- Codage de I’image animee et du son
Technologies de I’informa tion
associ6 pour /es supports de stockage num&ique jusqu’a environ
1,5 Mbit/s -
Partie 1: Systemes
Reference number
ISO/IEC 11172-1 :1993(E)

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SIST EN ISO/IEC 11172-1:1997
ISOAEC 11172~1:1993 (E)
Page
Contents
iii
Foreword .
iv
Introduction .
1
........................................................................................
Section 1: General
1
1.1 Scope .
............................................................................ 1
1.2 Normative references
.......................................................................... 3
Section 2: Technical elements
3
.
2.1 Defini tions .
11
..................................................................
2.2 Symbols and abbreviations
13
...................................................
2.3 Method of describing bit stream Syntax
15
2.4 Requirements .
Annexes
29
A Description of the System coding layer .
50
B List of patent holders .
0 ISO/IEC 1993
AI1 rights reserved. No part of this publication may be reproduced or utilized in any form or by
any means, electronie or mechanical, including photocopying and microfilm, without
permission in writing from the publisher.
ISOLEC Copyright Office l Case Postale 56 l CH 1211 Geneve 20 l Switzerland
Printed in Switzerland.
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SIST EN ISO/IEC 11172-1:1997
ISOAEC 11172~1:1993 (E)
o ISOAEC
Foreword
ISO (the International Organization for Standardization) and IEC (the Inter-
national Electrotechnical Commission) form the specialized System for
worldwide standardization. National bodies that are members of ISO or
IEC participate in the development of International Standards through
technical committees established by the respective organization to deal
with particular fields of technical activity. ISO and IEC technical com-
mittees collaborate in fields of mutual interest. Other international organ-
izations, governmental and non-governmental, in liaison with ISO and IEC,
also take part in the work.
In the field of information technology, ISO and IEC have established a joint
technical committee, ISO/IEC JTC 1. Draft International Standards adopted
by the joint technical committee are circulated to national bodies for vot-
ing. Publication as an International Standard requires approval by at least
75 % of the national bodies casting a vote.
International Standard lSO/IEC 11172-1 was prepared by Joint Technical
Committee ISO/IEC JTC 1, Information technology, Sub-Committee SC 29,
Coded representation of audio, picture, multimedia and hypermedia infor-
ma tion.
lSO/IEC 11172 consists of the following Parts, under the general title In-
forma tion technology - Coding of moving pictures and associated audio
for digital storage media at up to about 1,5 Mbit/s:
- Part 7: Systems
- Part 2: Video
- Part 3: Audio
- Part 4: Compliance testing
Annexes A and B of this part of lSO/IEC 11172 are for information only.
. . .
111

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Introduction
Note -- Readers interested in an overview of the MPEG Systems layer should read this Introduction and then
proceed to annex A, before retuming to the clauses 1 and 2. Since the System target decoder concept is
referred to throughout both the normative and informative clauses of this part of ISO/IEC 11172, it may
also be useful to refer to clause 2.4, and particularly 2.4.2, where the System target decoder is described.
The Systems specification addresses the Problem of combining one or more data streams from the Video and
audio parts of this International Standard with timing information to ferm a Single stream. Once combined
into a Single stream, the data are in a form well suited to digital storage or transmission. The syntactical
and semantic rules imposed by this Systems specification enable synchronized playback without overflow or
underflow of decoder buffers under a wide range of stream retrieval or receipt conditions. The scope of
syntactical and semantic rules set forth in the Systems specification differ: the syntactical rules apply to
Systems layer coding only, and do not extend to the compression layer coding of the Video and audio
specifications; by contrast, the semantic rules apply to the combined stream in its entirety.
The Systems specification does not specify the architecture or implementation of encoder or decoders.
However, bitstream properties do impose functional and performante requirements on encoders and decoders.
For instance, encoders must meet minimum clock tolerante requirements. Notwithstanding this and other
requirements, a considerable degree of freedom exists in the design and implementation of encoders and
decoders.
A prototypical audio/video decoder System is depicted in figure 1 to illustrate the function of an ISO/IEC
11172 decoder. The architecture is not unique -- System Decoder functions including decoder timing control
might equally well be distributed among elementar-y stream decoders and the Medium Specific Decoder -- but
this figure is useful for discussion. The prototypical decoder design does not imply any normative
requirement for the design of an ISO/IEC 11172 decoder. Indeed non-audio/video data is also allowed, but
not shown.
m-----B----
r ISO/IEC 11172
I
Audi
DeuKied
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I
audio
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ISO1 1172
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Digital II3ecodm 1
Storage
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ISO/IEC 11172
Prototypical ISO/IEC 11172 decoder
Figure 1 --
The prototypical ISO/IEC 11172 decoder shown in figure 1 is composed of System, Video, and Audio
decoders conforming to Parts 1,2, and 3, respectively, of ISOAEC 11172. In this decoder the multiplexed
coded representation of one or more audio and/or Video streams is assumed to be stored on a digital storage
medium (DSM), or network, in some medium-specific format. The medium specific format is not governed
by this International Standard, nor is the medium-specific decoding part of the prototypical ISO/IEC 11172
dtXOdH.
The prototypical decoder accepts as input an ISO/lEC 11172 multiplexed stream and relies on a System
Decoder to extract timing information from the stream. The System Decoder demultiplexes the stream, and
the elementary streams so produced serve as inputs to Video and Audio decoders, whose outputs are decoded
Video and audio Signals. Included in the design, but not shown in the figure, is the flow of timing
information among the System Decoder, the Video and Audio Decoders, and the Medium Specific Decoder.
iv

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0 ISOAEC ISOAEC 11172-1: 1993 (E)
The Video and Audio Decoders are synchronized with each other and with the DSM using this timing
information.
ISO/IEC 11172 multiplexed streams are constructed in two layers: a System layer and a compression layer.
The input stream to the System Decoder has a System layer wrapped about a compression layer. Input
streams to the Video and Audio decoders have only the compression layer.
Operations performed by the System Decoder either apply to the entire ISO/IEC 11172 multiplexed stream
(“multiplex-wide operations”), or to individual elementary streams (“stream-specific opemtions”). The
ISO/IEC 11172 System layer is divided into two sub-layers, one for multiplex-wide operations (the pack
layer), and one for stream-specific operations (the packet layer).
0.1 Multiplex-wide operations (pack layer)
Multiplex-wide operations include the coordination of data retrieval off the DSM, the adjustment of clocks,
and the management of buffers. The tasks are intimately related. If the rate of data delivery off the DSM is
controllable, then DSM delivery may be adjusted so that decoder buffers neither overflow nor underflow;
but if the DSM rate is not controllable, then elementar-y stream decoders must Slave their timing to the
DSM to avoid Overflow or underflow.
ISO/IEC 11172 multiplexed streams are composed of Packs whose headers facilitate the above tasks. Pack
headers specify intended times at which each byte is to enter the System decoder from the DSM, and this
target arrival schedule serves as a reference for clock correction and buffer management. The schedule need
not be followed exactly by decoders, but they must compensate for deviations about it.
An additional multiplex-wide Operation is a decoder’s ability to establish what resources are required to
decode an ISO/IEC 11172 multiplexed stream. The first pack of each ISO/IEC 11172 multiplexed stream
conveys Parameters to assist decoders in this task. Included, for example, are the stream’s maximum data
rate and the highest number of simultaneous Video channels.
Individual stream operations (packet layer)
0.2
The principal stream -specific operations are 1) demultiplexing, and 2) synchronizing playback of multiple
elementar-y streams. These topics are discus sed next.
0.2.1 Demultiplexing
On encoding, ISO/IEC 11172 multiplexed streams Elementary streams may include private, reserved, and padding stre and Video streams. The streams are temporally subdivided into packets, and the packets are serialized. A
packet co~~tahs coded bytes from one and only one elementary stream.
Both fixed and variable packet lengths are allowed subject to constraints in 2.4.3.3 and in 2.4.5 and 2.4.6.
On decoding, demultiplex ing is required to reconstitute elementar-y stre(ams from the IS O/IEC 11172
is made possible by stream id Codes in packet headers
mul tiplexed stream. This -
0.2.2 Synchronization
Synchronization cunong multiple strecams is effected with presentation time stamps in the ISO/IEC 11172
multiplexed stream. The time stamps are in units of 90kHz. Playback of N streams is synchronized by
adjusting the playback of all streams to a master time base rather than by adjusting the playback of one
stream to match that of another. The master time base may be one of the N decoders’ clocks, the DSM or
channel clock, or it may be some extemal clock.
Because presentation time-stamps apply to the decoding of individual elementar-y streams, they reside in the
packet layer. End-to-end synchronization occurs when encoders record time-stamps at Capture time, when
the time stamps propagate with associated coded data to decoders, and when decoders use those time-stamps
to schedule presentations.
Synchronization is also possible with DSM timing time stamps in the multiplexed data st.re
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0.2.3 Relation to compression layer
The packet layer is independent of the compression layer in some senses, but not in all. It is independent in
the sense that packets need not start at compression layer start codes, as defined in parts 2 and 3. For
example, a Video packet may statt at any byte in the Video stream. However, time stamps encoded in
packet headers apply to presentation times of compression layer co~vXructs (namely, presentation units).
0.3 System reference decoder
Part 1 of ISO/IEC 11172 employs a “System target decoder,” (SID) to provide a formalism for timing and
buffering relationships. Because the STD is parameterized in terms of fields defined in ISO/IEC 11172 (for
example, buffer sizes) each ISO/IEC 11172 multiplexed stream leads to its own parameterization of the
STD. It is up to encoders to ensure that bitstreams they produce will play in normal Speed, forward play on
corresponding STDs. Physical decoders may assume that a stream plays properly on its SID; the physical
decoder must compensate for ways in which its design differs from that of the STD.
Vi

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SIST EN ISO/IEC 11172-1:1997
INTERNATIONAL STANDARD o lSo’IEC ISO/IEC 11172-1:1993 (E)
Information technology - Coding of moving
pictures and associated audio for digital storage
media at up to about 1,5 Mbit/s -
Part 1:
Systems
Section 1: General
1.1 Scope
This patt of ISO/IEC 11172 specifies the System layer of the coding. It was developed principally to
support the combination of the Video and audio coding methods defined in ISO/IEC 11172-2 and ISO/IEC
11172-3. The System layer supports five basic functions:
a) the synchronization of multiple compressed streams on playback,
b) the interleaving of multiple compressed streams into a Single stream,
c) the initialization of buffering for playback Start up,
d) continuous buffer management, and
e) time identification.
An ISO/IEC 11172 multiplexed bit stream is constructed in two layers: the outermost layer is the System
layer, and the innermost is the compression layer. The System layer provides the functions necessary for
using one or more compressed data streams in a System. The Video and audio parts of this specification
define the compression coding layer for audio and Video data. Coding of other types of data is not defined by
the specification, but is supported by the System layer provided that the other types of data adhere to the
constraints defined in clause 2.4.
1.2 Normative references
The following International Standards contain provisions which, through reference in this text, constitute
provisions of this part of ISO/IEC 11172. At the time of publication, the editions indicated were valid. All
standards are subject to revision, and Parties to agreements bczsed on this pczrt of ISO 11172 are encouraged
to investigate the possibility of applying the most recent editions of the Standyards indicated below.
Members of IEC and ISO maintain registers of currently valid International Standards.
ISO/IEC 11172-2:1993 Information technology - Coding of moving pictures and associated audio for digital
storage media at up to about 1,5 MbitLs - Part 2: Video.
ISO/IEC 11172-3: 1993 Information technology - Coding of moving pictures and associated audio for digital
storage media at up to about 1,5 Mbit/s - Part 3 Audio.
CCIR Recommendation 601-2 Encoding Parameters of digital television for Studios.
CCIR Report 624-4 Characteristics of Systems for monochrome and colour television.
CCIR Recommendation 648 Recording of audio Signals.
CCIR Report 955-2 Sound broadcasting by satellite for portable and mobile receivers, including Annex IV
Summry description of Advanced Digital System II.

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SIST EN ISO/IEC 11172-1:1997
o ISO/IEC
ISOAEC 11172~1:1993 (E)
CCIIT Recommendation J. 17 Pre-emphasis used on Sound-Programme Circuits.
IEEE Draft Standard PllWD2 1990 Specijkation for the implementation of 8x 8 inverse discrete cosine
transform”.
IEC publication 908:1987 CD Digital Audi0 System.

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SIST EN ISO/IEC 11172-1:1997
o ISOAEC ISOAEC 11172-1: 1993 (E)
Section 2: Technical elements
2.1 Definitions
For the purposes of ISO/IEC 11172, the following definitions apply. If specific to a part, this is noted in
Square brackets.
2.1.1 ac coefficient [Video]: Any DCT coefficient for which the frequency in one or both dimensions
is non-Zero.
In the case of compressed audio an access unit is an audio access unit. In
2.1 .2 access unit [System]:
an access un it is the coded representation of a picture.
the case of compressed Video
n [audio]: A subdivision of the digital representation of an audio Signal
2. 1.3 adaptive segmentatio
in variable Segments of time.
2.1.4 adaptive bit allocation [audio]: The assignment of bits to subbands in a time and frequency
varying fashion according to a psychoacoustic model.
2.1.5 adaptive noise allocation [audio]: The assignment of coding noise to freq uency bands in a
time and frequency varying fashion according to a psychoacoustic model.
2.1.6 alias [audio]: Mirrored Signal component resulting from sub-Nyquist sampling.
2.1.7 analysis filterbank [audio]: Filterbank in the encoder that transforms a broadband PCM audio
Signal into a set of subsampled subband scunples.
2.1.8 audio access unit [audio]: For Layers 1 and 11 part of the encoded bitstream which ca.11 be decoded by itself, where decoded means “fully reconstructed
Sound”. For Layer 111 an audio access unit is part of the bitstream that is decodable with the use of
previously acquired main information.
2.1.9 audio buffer [audio]: A buffer in the System target decoder for storage of compressed audio data.
2.1.10 audio sequence [audio]: A non-interrupted series of audio frames in which the following
Parameters are not changed:
-ID
- Layer
- Sampling Frequency
- For Layer 1 and 11: Bitrate index
2.1.11 backward motion vector [Video]: A motion vector that is used for motion compensation
from a reference picture at a later time in display Order.
2.1.12 Bark [audio]: Unit of critical band rate. The Bark scale is a non-linear mapping of the frequency
scale over the audio range closely corresponding with the frequency selectivity of the human ear across the
band.
2.1.13 bidirectionally predictive-coded picture;
B-picture [Video]: A picture that is coded
using motion compensated prediction from a pcist andlor future reference picture.
2.1.14 bitrate: The rate at which the compressed bitstream is delivered from the storage medium to the
input of a decoder.
2.1.15 block companding [audio]: Normalizing of the digital representation of an audio Signal
within a certain time period.
2.1.16 block [Video]: An 8-row by 8-column orthogonal block of pels.
2.1.17 bound [audio]: The lowest subband in which intensity stereo coding is used.

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2.1.18 byte aligned: A bit in a coded bitstream is byte-aligned if its position is a multiple of 8-bits
from the first bit in the stream.
2.1.19 byte: Sequence of 8-bits.
2.1.20 channel: A digital medium that stores or transports an ISO/IEC 11172 stream.
2.1.21 channel [audio]: The left and right channels of a stereo Signal
2.1.22 chrominance (component) [Video]: A matrix, block or Single pel representing one of the
two colour differente Signals related to the Primar-y colours in the manner defined in CCIR Ret 601. The
Symbols used for the colour differente Signals are Cr and Cb.
2.1.23 coded audio bitstream [audio]: A coded representation of an audio Signal as specified in
ISO/IEC 11172-3.
2.1.24 coded Video bitstream [Video]: A coded representation of a series of one or more pictures as
specified in ISO/IEC 11172-2.
2.1.25 coded Order [Video]: The Order in which the pictures are stored and decoded. This Order is not
necessarily the same as the display Order.
2.1.26 coded representation: A data element as represented in its encoded form.
2.1.27 coding Parameters [Video]: The set of user-definable Parameters that ch‘aracterize a coded Video
bitstream. Bitstreams are characterised by coding Parameters. Decoders that they are capable of decoding.
2.1.28 component [Video]: A matrix, block or Single pel from one of the three matrices (luminance
and two chrominance) that make up a picture.
2.1.29 compression: Reduction in the number of bits used to represent an item of data.
2.1.30 constant bitrate coded Video [Video]: A compressed Video bitstream with a constant
average bitrate.
2.1.31 constant bitrate: Operation where the bitrate is constant from Start to finish of the compressed
bitstream.
2.1.32 constrained Parameters [Video]: The values of the set of coding pclrameters defined in
2.4.3.2 of ISO/IEC 11172-2.
2.1.33 constrained System Parameter stream (CSPS) [System]: An ISO/IEC 11172
multiplexed stream for which the constraints defined in 2.4.6 of this pczrt of ISO/IEC 11172 apply.
2.1.34 CRC: Cyclic redundancy Code.
2.1.35 critical band rate [audio]: Psychoacoustic function of frequency. At a given audible
frequency it is proportional to the number of critical bands below that frequency. The units of the critical
band rate scale arc Barks.
2.1.36 critical band [audio]: Psychoacoustic measure in the spectral domain which corresponds to the
frequency selectivity of the human ear. This selectivity is expressed in Bark.
2.137 data element: An item of data as represented before encoding and after decoding.
2.138 dc-coefficient [Video]: The DCT coefficient for which the frequency is zero in both
dimensions.
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0 ISOAEC
2.1.39 dc-coded picture; D-picture [Video]: A picture that is coded using only information from
itself. Of the DCT coefficients in the coded representation, only the dc-coefficients are present.
2.1.40 DCT coefficient: The amplitude of a specific cosine basis function.
2.1.41 decoded stream: The decoded reconstruction of a compressed bitstream.
2.1.42 decoder input buffer [Video]: The first-in first-out (FIFO) buffer specified in the Video
buffering verifier.
2.1.43 decoder input rate [Video]: The data rate specified in the Video buffering verifier and encoded
in the coded Video bitstream.
2.1.44 decoder: An embodiment of a decoding process.
2.1.45 decoding (process): The process defined in ISO/IEC 11172 that reads an input coded bitstream
and produces decoded pictures or audio samples.
2.1.46 decoding time-stamp; DTS [System]: A field that may be present in a packet header that
indicates the time that an access unit is decoded in the System target decoder.
storage or transmission to
2.1.47 de-emphasis [ audio]: Filtering applied to a linear distortion due to emphasis.
2.1.48 dequantization [Video]: The process of rescaling the quantized DCT coefficients after their
representation in the bitstream has been decoded and before they are presented to the inverse DCT.
2.1.49 digital storage media; DSM: A digital storage or transmission device or System.
2.1.50 discrete cosine transform; DCT [Video]: Either the forward discrete cosine transform or the
inverse discrete cosine transform. The DCT is an invertible, discrete orthogonal transformation. The
inverse DCT is defined in annex A of ISO/IEC 11172-2.
2.1.51 display Order [Video]: The Order in which the decoded pictures should be displayed. Normally
this is the same Order in which they wer-e presented at the input of the encoder.
2.1.52 dual channel mode [audio]: A mode, where two audio channels with independent Programme
contents (e.g. bilingual) care encoded within one bitstream. The coding process is the s mode.
2.1.53 editing: The process by which one or more compressed bitstreams are manipulated to produce a
new compressed bitstream. Conforming edited bitstreams must meet the requirements defined in ISOLIEC
11172.
2.1.54 elementary stream [System]: A generic term for one of the coded Video, coded audio or other
coded bitstreams.
2.1.55 emphasis [audio]: Filtering applied to an audio Signal before storage or transmission to
improve the signal-to-noise ratio at high frequencies.
2.1.56 encoder: An embodiment of an encoding process.
2.1.57 encoding (process): A process, not specified in ISO/IEC 11172, that reads a stream of input
pictures or audio samples and produces a valid coded bitstream as defined in ISO/IEC 11172.
2.1.58 entropy coding: Variable length lossless coding of the digital representation of a Signal to
reduce redundancy.
2.1.59 fast forward playback [Video]: The process of displaying a sequence, or parts of a sequence,
of pictures in display-order faster than real-time.

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2.1.60 FFT: Fast Fourier Transformation. A fast algorithm for perfonning a discrete Fourier transform
(an orthogonal transform).
2.1.61 filterbank [audio]: A set of band-pass filters covering the entire audio frequency range.
2.1.62 fixed Segmentation [ audio]: A subdivision of the digital representation of an audio Signal
into fixed Segments of time.
2.1.63 forbidden: The term “forbidden” when used in the clauses defining the coded bitstream indicates
that the value shall never be used. This is usually to avoid emulation of start Codes.
2.1.64 forced updating [Video]: The process by which macroblocks are intra-coded from time-to-time
to ensure that mismatch errors between the inverse DCT processes in encoders and decoders cannot build up
excessively.
mo tion
2.1.65 forward motion vector [Video]: A vector that is used for motion compensation from
a reference picture at an earlier time in display Order.
2.1.66 frame [audio]: A part of the audio Signal that corresponds to audio PCM samples from an
Audio Access Unit.
2.1.67 free format [audio]: Any bitrate other than the defined bitrates that is less than the maximum
valid bitrate for each layer.
2.1.68 future reference picture [v tideo]: The future reference picture is the reference picture that
occurs at a later time than the current picture in display Order.
2.1.69 granules [Layer 11] [audio]: The set of 3 consecutive subband samples from all 32 subbands
that are considered together before qu 2.1.70 granules [Layer 1111 [audio]: 576 frequency lines that carry their own side information.
2.1.71 group of pictures [Video]: A series of one or more coded pictures intended to assist random
access. The group of pictures is one of the layers in the coding syntax defined in ISO/IEC 11172-2.
2.1.72 Hann window [audio]: A time function applied scunple-by-scunple to a block of audio samples
before Fourier transformation.
2.1.73 Huffman coding: A specific method for entropy coding.
2.1.74 hybrid filterbank [audio]: A serial combination of subband filterbank and MDCT.
2.1.75 IMDCT [audio]: Inverse Modified Discrete Cosine Transform.
2.1.76 intensity stereo [audio]: A method of exploiting stereo irrelevante or redundancy in
stereophonic audio Programmes bc?sed on retaining at high frequencies only the energy envelope of the right
and left channels.
2.1.77 interlace [Video]: The property of conventional television pictures where alternating lines of
the picture represent different instances in time.
2.1.78 intra coding [Video]: Coding of a macroblock or picture that uses information only from that
macroblock or picture.
2.1.79 intra-coded picture; 1-picture [Video]: A picture coded using information only from itself.
2.1.80 ISO/IEC 11172 (multiplexed) stream [System]: A bitstream composed of Zero or more
elementar-y streams combined in the manner defined in this p‘art of ISO/IEC 11172.

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2.1.81 joint stereo coding [audio]: Any method that exploits stereophonic irrelevante or
stereophonic redundancy.
2.1.82 joint stereo mode [audio]: A mode of the audio coding algorithm using joint stereo coding.
2.1.83 layer [audio]: One of the levels in the coding hierarchy of the audio System defined in ISO/IEC
11172-3.
2.1.84 layer [Video and Systems]: One of the levels in the data hierarchy of the Video and System
specifications defmed in this part of ISO/IEC 11172 and ISO/IEC 11172-2.
2.1.85 luminance (component) [Video]: A matrix, block or Single pel representing a monoc
...