SIST EN 62842:2016

SLOVENSKI STANDARD
SIST EN 62842:2016
01-marec-2016
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File allocation system with minimized reallocation for multimedia home server (TA 8)
(IEC 62842:2015)
Multimedia-Homeserversysteme - System zur Dateizuordnung mit minimaler
Umverteilung (IEC 62842:2015)
Système d'allocation de fichiers avec réallocation minimisée pour serveur domestique
multimedia (IEC 62842:2015)
Ta slovenski standard je istoveten z: EN 62842:2015
ICS:
33.160.60 9HþSUHGVWDYQLPXOWLPHGLMVNL Multimedia systems and
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SIST EN 62842:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 62842:2016

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SIST EN 62842:2016


EUROPEAN STANDARD EN 62842

NORME EUROPÉENNE

EUROPÄISCHE NORM
December 2015
ICS 33.160.60

English Version
File allocation system with minimized reallocation for multimedia
home server (TA 8)
(IEC 62842:2015)
Système d'allocation de fichiers avec réallocation minimisée Multimedia-Homeserversysteme - System zur
pour serveur domestique multimedia Dateizuordnung mit minimaler Umverteilung
(IEC 62842:2015) (IEC 62842:2015)
This European Standard was approved by CENELEC on 2015-10-14. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.


European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN 62842:2015 E

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SIST EN 62842:2016
EN 62842:2015
European foreword
The text of document 100/2367/CDV, future edition 1 of IEC 62842, prepared by Technical Area 8
"Multimedia home systems and applications for end-use network" of IEC/TC 100 "Audio, video and
multimedia systems and equipment" was submitted to the IEC-CENELEC parallel vote and approved
by CENELEC as EN 62842:2015.

The following dates are fixed:
• latest date by which the document has to be (dop) 2016-07-14
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2018-10-14
• latest date by which the national
standards conflicting with the
document have to be withdrawn

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.

Endorsement notice
The text of the International Standard IEC 62842:2015 was approved by CENELEC as a European
Standard without any modification.
2

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SIST EN 62842:2016
EN 62842:2015

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
ISO/IEC 13346 series Information technology - Volume and file - series
structure of write-once and rewritable
media using non-sequential recording for
information interchange
ISO/IEC 13346-1 1995 Information technology - Volume and file - -
structure of write-once and rewritable
media using non-sequential recording for
information interchange -- Part 1: General
ISO/IEC 13346-3 1999 Information technology - Volume and file - -
structure of write-once and rewritable
media using non-sequential recording for
information interchange - Part 3: Volume
structure
ISO/IEC 13346-4 1999 Information technology - Volume and file - -
structure of write-once and rewritable
media using non-sequential recording for
information interchange - Part 4: File
structure

3

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SIST EN 62842:2016

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SIST EN 62842:2016



IEC 62842

®


Edition 1.0 2015-09




INTERNATIONAL



STANDARD



















Multimedia home server systems – File allocation system with minimized

reallocation



























INTERNATIONAL

ELECTROTECHNICAL


COMMISSION





ICS 33.160.60 ISBN 978-2-8322-2843-2



  Warning! Make sure that you obtained this publication from an authorized distributor.


® Registered trademark of the International Electrotechnical Commission

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SIST EN 62842:2016
– 2 – IEC 62842:2015 © IEC 2015
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, abbreviations and notation . 7
3.1 Terms and definitions . 7
3.2 Abbreviations . 11
3.3 Notation . 11
4 Precondition and the policy . 11
4.1 Preconditions . 11
4.2 Policy . 12
5 Method to be applied-CoPo2 . 12
6 Explanation of basic method CoPo2 . 14
6.1 Basics . 14
6.2 Two choices to apply CoPo2 to an existing partition scheme . 14
6.2.1 General . 14
6.2.2 Applying to an existing partition . 14
6.2.3 Applying to a virtual container partition . 15
6.2.4 Choice conclusion . 16
6.3 Management tables for CoPo2 . 16
6.3.1 General . 16
6.3.2 Region configuration master partition table . 18
6.3.3 Multilevel-divided-partition management tables . 18
6.4 Functions required to implement CoPo2 . 18
6.4.1 General . 18
6.4.2 Initialize . 18
6.4.3 Manage-multilevel-divided-partitions . 18
7 Considerations on the size of management tables . 19
7.1 General . 19
7.2 Multilevel-divided-partition allocation table size . 19
7.2.1 Blu-ray . 19
7.2.2 HDD . 19
8 Applying CoPo2 to UDF . 19
8.1 Storage media to be applied . 19
8.2 Basics when UDF volume format is applied to HDD . 20
8.3 Basics to apply management tables to UDF . 20
8.3.1 Master divided-partition table . 20
8.3.2 Using the implementation use field of the partition descriptor . 20
8.3.3 Multilevel-divided-partition allocation table . 21
9 Data structures applied to UDF . 21
9.1 General . 21
9.1.1 Entity identifier . 21
9.1.2 IdentifierSuffix . 21
9.2 Volume structure . 21
9.2.1 Logical volume descriptor . 21

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9.2.2 Logical volume integrity descriptor . 22
9.2.3 Partition descriptor . 23
9.3 File data structures . 24
9.3.1 Partition header descriptor . 24
9.3.2 CoPo2 partition header descriptor . 24
9.3.3 Space bitmap descriptor . 25

Figure 1 – Virtual container partition . 16
Figure 2 – Management tables for CoPo2 . 17

Table 1 – Domain identifier suffix field format . 22
Table 2 – Domain flags . 22
Table 3 – ImplementationUse format . 23
Table 4 – CoPo2ManageTable . 25

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MULTIMEDIA HOME SERVER SYSTEMS –
FILE ALLOCATION SYSTEM WITH MINIMIZED REALLOCATION

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62842 has been prepared by technical aerea 8: Multimedia home
systems and applications for end-user network of IEC technical committee 100: Audio, video
and multimedia systems and equipment.
The text of this technical report is based on the following documents:
CDV Report on voting
100/2367/CDV 100/2459/RVC

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

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SIST EN 62842:2016
IEC 62842:2015 © IEC 2015 – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

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INTRODUCTION
1
Recently, hard disk and Blu-ray Disc recorders have become popular in the home to record
television programmes. Normally a Hard Disk Recorder (HDR) is used for time shift and a Blu-
ray Disc (BD) is used for library. When an HDR is used for time shift, television programmes
are recorded and played, then many of them are deleted to reuse the spaces for other
programmes to be recorded. These programmes are stored as files in a hard disk drive (HDD)
using a file system. Continuous recording and deletion of programmes involves the
continuous storing and deletion of files in the file system. Television programme streams
include at least videos and an electronic programme guide (EPG). The HDR stores videos in a
long, variable length file depending on the quality and recording hours. Compared with videos,
EPG related information is stored in a shorter file or files but is often updated. This continuous
creation, deletion and updating of files of different lengths finally causes the files to be stored
in fragments, and the system performance becomes very low.
In a computer, defragmentation tools are provided to solve the problem of a fragmented file
system. Normally defragmentation with reallocation of files in sequence takes a long time and
the end user cannot but wait for the completion of the defragmentation, with no other activity.
In the home server environment, a smarter solution to resolve this problem needs to be
provided.
The recent newly developed HDD features will be reflected in the next version of the standard.
___________
1
Blu-ray Disc™ is a trademark of the Blu-ray Disc Association. This information is given for the convenience of
users of this document and does not constitute and endorsement by IEC of the product named.

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SIST EN 62842:2016
IEC 62842:2015 © IEC 2015 – 7 –
MULTIMEDIA HOME SERVER SYSTEMS –
FILE ALLOCATION SYSTEM WITH MINIMIZED REALLOCATION



1 Scope
This International Standard specifies the method for allocating requested file space with no
fragmentation, to minimize the need for reallocation of fragmented files in the Universal Disc
Format (UDF) file system applied to hard disk drives used in hard disk recorders.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
ISO/IEC 13346 (all parts), Information technology – Volume and file structure of write-once
and rewritable media using non-sequential recording for information
ISO/IEC 13346-1:1995, Information technology – Volume and file structure of write-once and
rewritable media using non-sequential recording for information interchange – Part 1: General
ISO/IEC 13346-3:1999, Information technology – Volume and file structure of write-once and
rewritable media using non-sequential recording for information interchange – Part 3: Volume
structure
ISO/IEC 13346-4:1999, Information technology – Volume and file structure of write-once and
rewritable media using non-sequential recording for information interchange – Part 4: File
structure
OSTA UDF2.01:200, Information technology – OSTA Universal Disk Format Specification,
Revision 2.01
Secure Universal Disk Format Specification Revision 1.00, Optical Storage Technology
Association (OSTA), http://www.osta.org/
3 Terms, definitions, abbreviations and notation
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
partition
region allocated to a file system by a disk volume space management system
3.1.2
virtual container partition
virtual partition containing a partition which has a minimum size of power-of-2 of allocation
unit size of the disk

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3.1.3
buddy
region allocation method where a given region having a power-of-2 unit size is recursively
divided into two equal size regions (as 'buddies') until it reaches to one unit in size and, if a
region of a given size is requested, the smallest free power-of-2 unit size region that can
contain the requested size region is allocated
3.1.4
Concatenation of power of 2
CoPo2
basic allocation method of this standard
3.1.5
divide
process of obtaining divided-partitions through first identifying master-divided partitions, then
applying the buddy method to them to get divided-partitions and finally allocating divided-
partition numbers
3.1.6
master-dividing
process of identifying the master-divided-partition in the first process of dividing
Note 1 to entry: When the size of a partition is a power-of-2 unit size, the partition as a whole constitutes a
master-divided partition.
Note 2 to entry: When the size of a partition is expressed as the sum of mutually different power-of-2 sizes with
the power-of-2 size that constitutes the sum, constitute the partition as a concatenation of the areas in the
sequence of those sizes as master-divided partitions in decreasing order of size.
3.1.7
master-divided-partition
divided partition identified by master-dividing
3.1.8
one unit in size
predetermined minimum unit of memory size that can be allocated
3.1.9
divided-partition
partition identified by dividing the master-divided partitions in a given partition recursively in
half until it reaches one unit in size
3.1.10
divided-partition level
level value of a divided-partition expressed by the power-of-2 value of the divided partition
compared to unit size
Note 1 to entry: This is often abbreviated as level n (where n specifies level number).
3.1.11
partition level
level n
abbreviation of divided-partition level, normally used in a simple form, 'level n'
3.1.12
divided-partition pair
pair of divided-partition formed by dividing a divided-partition into two halves as buddies

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3.1.13
divided-partition number
number assigned to divided-partitions in the process of dividing a given partition from top
level to the lowest level incrementally
Note 1 to entry: Numbers are assigned to each divided-partition from top to bottom and from left to right in the
same level with the starting number 1, counting up by one.
3.1.14
master-divided-partition number
divided-partition number assigned to each master-divided-partition
3.1.15
master-divided partitions table
table for managing the master-divided partitions
3.1.16
master-divided-partition number management table
table for managing the master-divided-partition number in contrast with each divided-partition
level
3.1.17
end position management table
table for managing the maximum divided-partition number assigned in each divided-partition
level
3.1.18
highest divided-partition level management table
table for managing the highest divided-partition level for the partition
3.1.19
multilevel-divided partition management tables
three tables for managing the divided-partitions
Note 1 to entry: The three tables are the master divided-partition number management table, the end position
management table and the highest divided-partition level management table.
3.1.20
multilevel-divided-partition allocation table
table for managing the multilevel-divided partitions state in each level with 2 bits
3.1.21
segment
region to be taken or allocated from a partition
Note 1 to entry: If the size of a region is power-of-2 unit size, the region consists of one divided partition.
Note 2 to entry: If the size of a region is a sum of polynomials of power-of-2 of a unit size, the region consists of a
concatenation of multilevel divided-partitions, each corresponding to one polynomial component, and it is taken
from the container divided-partition for a segment.
3.1.22
multilevel-dividing
procedure for obtaining a region as a segment, consisting of the concatenation of multilevel
divided-partition decreasing order in size, of which each corresponds to one power-of-2
polynomial component

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3.1.23
container divided partition for a segment
simple power-of-2 region determined by rounding up the size of a polynomial-based requested
segment to the size of the nearest simple power-of-2 region and that simple region will consist
of the segment to be allocated and adjacent-multilevel-segment
3.1.24
adjacent-multilevel-segment
segment adjacent to the allocated multilevel-segment of which each component divided-
partition is allocated in increasing order of size, and which constitutes the rest of the
container divided-partition for a segment
3.1.25
first-pass-allocation
first step to allocate a segment, to obtain a minimum divided partition including the requested
segment
Note 1 to entry: If a segment is a single level divided-partition, the allocation is completed, but if a segment is
multilevel, the process continues to a second-pass allocation.
3.1.26
second-pass-allocation
second step to allocate a multilevel segment, in a segment allocation, where the multilevel-
dividing is applied to the divided-partition obtained from the first-pass-allocation
3.1.27
provisional-allocation
procedure to get a segment, where, if a divided-partition including the target segment is not
found, a search for the available upper level of a divided-partition is requested and the
divided-partition found is allocated as provisional allocation
Note 1 to entry: After getting a provisional divided-partition, first-pass-allocation continues and in the case of
allocating a multilevel-segment, second-pass-allocation continues.
3.1.28
allocation state
divided-partition state in view of allocation, classified into available, occupied and reserved
3.1.29
available
allocation state showing the divided-partition is free to use, meaning available
Note 1 to entry: Divided-partitions are classified into first-pass-available and second-pass-available. When
searching for a free divided-partition, start by searching for first-pass-available and then search for second-pass-
available.
3.1.30
first-pass-available
initial available state assigned to free divided-partitions
Note 1 to entry: When an occupied divided-partition becomes free, its allocation state is set as first-pass-
available.
3.1.31
second-pass-available
available allocation state assigned to each component divided-partition of adjacent-multilevel-
segments, after allocation of the multilevel-segment
3.1.32
occupied
allocation state showing the divided-partition is in use

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3.1.33
reserved
divided-partition allocation state that is not appropriate to classify into available or occupied
Note 1 to entry: Divided-partitions other than available or occupied are set as reserved. When getting a segment
through provisional-allocation, the allocated top divided-partition and the divided-partitions in lower levels shall be
set as reserved.
3.1.34
master boot record
conventional partitioning record in logical block address 0 of HDD
3.1.35
logical block address
address scheme used for HDD volume space
3.1.36
logical sector number
address scheme used for UDF volume in HDD volume space
Note 1 to entry: UDF volume might be restricted in the first partition of HDD. LSN = LBA − 63.
3.1.37
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...