1、 IEC 62842 Edition 1.0 2015-09 INTERNATIONAL STANDARD Multimedia home server systems File allocation system with minimized reallocation IEC 62842:2015-09(en) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2015 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specified, no part of th
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10、u wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csciec.ch. IEC 62842 Edition 1.0 2015-09 INTERNATIONAL STANDARD Multimedia home server systems File allocation system with minimized reallocation INTERNATIONAL ELECTROTECHNICAL
11、 COMMISSION ICS 33.160.60 ISBN 978-2-8322-2843-2 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. 2 IEC 62842:2015 IEC 2015 CONTENTS FOREWORD . 4 INTRODUCTION . 6 1 Scope 7 2 Normative referenc
12、es 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 a
13、pply 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
14、.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 allocati
15、on 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 fie
16、ld 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 IEC 62842:2015 IEC 2015 3 9.2.2 Logica
17、l 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 Tabl
18、e 1 Domain identifier suffix field format . 22 Table 2 Domain flags . 22 Table 3 ImplementationUse format . 23 Table 4 CoPo2ManageTable 25 4 IEC 62842:2015 IEC 2015 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ MULTIMEDIA HOME SERVER SYSTEMS FILE ALLOCATION SYSTEM WITH MINIMIZED REALLOCATION FOREWORD
19、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 electric
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28、se 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
29、 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 o
30、f 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 votin
31、g indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. 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:/webs
32、tore.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. 6 IEC 62842:2015 IEC 2015 INTRODUCTION Recently, hard disk and
33、 Blu-ray Disc 1recorders 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
34、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
35、 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, del
36、etion 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
37、 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 versi
38、on of the standard. _ 1Blu-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. IEC 62842:2015 IEC 2015 7 MULTIMEDIA HOME SERVER SYSTEMS FILE ALLOCATION SY
39、STEM 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
40、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 (includin
41、g 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
42、-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
43、 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, O
44、ptical 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 manageme
45、nt 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 8 IEC 62842:2015 IEC 2015 3.1.3 buddy region allocation method where a given region having a power-of-2 unit size is recursively divided int
46、o 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 stan
47、dard 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
48、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
49、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 unt
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