Header Object Protection for a Data Stream

(19)

(11)

EP 1 396 978 A8

(12)	CORRECTED EUROPEAN PATENT APPLICATION

(48)	Corrigendum issued on:
	23.06.2004 Bulletin 2004/26

(43)	Date of publication:
	10.03.2004 Bulletin 2004/11

(21)	Application number: 03020076.0

(22)	Date of filing: 04.09.2003

(51)	International Patent Classification (IPC)⁷: H04L 29/06

(84)	Designated Contracting States:
	AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
	Designated Extension States:
	AL LT LV MK

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Priority:

04.09.2002 US 235587

(71)	Applicant: MICROSOFT CORPORATION
	Redmond, Washington 98052 (US)

(72)	Inventors:
	Adent, Daniel Bellevue Washington 98007 (US) West, Cory Central Piont Oregon 97502 (US) Dublish, Pratul Sammamish Washington 98074 (US) Strom, Clifford P. Sammamish Washington 98074 (US) Crites, Brian D. Sammamish, Washington 98074 (US)

(74)	Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät
	Maximilianstrasse 58 80538 München 80538 München (DE)

(54)	Header Object Protection for a Data Stream

(57) A header object for a data file is comprised of sub-objects which specify properties of the data stream and contains information needed to properly verify and interpret the information within the data object. In order to allow the protection of any set of sub-objects without requiring that the sub-objects follow any specific ordering, a new sub-object is introduced which includes region specifiers identifying regions within sub-objects and verification information for those regions. This new sub-object in the header object allows the modification of non-protected regions and reorganization of sub-objects in a header without invalidating verification information.
For example, one data stream format is the Advanced Streaming Format (ASF), which is an extensible file format designed to store coordinate multimedia data.