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FYI: Profiles and Levels in MPEG 4

From: Karl Dubost <karl@w3.org>
Date: Thu, 2 Sep 2004 07:58:28 -0400
Message-Id: <6718C63A-FCD7-11D8-9ACF-000A95718F82@w3.org>
To: www-qa@w3.org

	4.  	What are Profiles and Levels?

  Profiles and levels are interoperability/Conformance points. In order 
to make sure that MPEG-4 products work with other MPEG-4 products from 
other vendors, conformance points are developed. These points specify 
items such as
	▪ 	 Tools that can be used
	▪ 	 Bitrates
	▪ 	 Image Sizes
	▪ 	 Number of objects

  With out these Profiles and Levels, there would be no way to know that 
one product could work with another. For more information on MPEG-4 
visual profiles and levels, see http://www.m4if.org/resources/profiles.

	5. Why are there so many profiles and levels?

  MPEG-4 is a very rich toolbox that targets a number of different 
applications. Some of these applications are Studio editing, 
Interactive broadcast, Internet Streaming, and wireless devices.Each 
application has its own set of requirements. For example, Studio 
applications need very large image sizes and high decoding capacity 
that could never be supported on a small wireless device. To support 
the different applications, conformance points are developed that 
permit different vendors to develop products that meet the requirements 
of their industry. If a product conforms to a certain profile and 
level, then it will interoperate with other products that conform to 
the same profile and level.

Karl Dubost - http://www.w3.org/People/karl/
W3C Conformance Manager
*** Be Strict To Be Cool ***

Received on Thursday, 2 September 2004 11:58:29 UTC

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