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Re: FYI: Profiles and Levels in MPEG 4

From: Lofton Henderson <lofton@rockynet.com>
Date: Thu, 02 Sep 2004 09:18:55 -0600
Message-Id: <>
To: Karl Dubost <karl@w3.org>
Cc: www-qa@w3.org

Some interesting discussion of MPEG profiles and levels recently occurred 
in the middle of an SVG thread (member-only):


It is interesting, the specificity with which MPEG defines what comprises 
MPEG profiles and levels:  profiles are defined by functional 
inclusion/exclusion, and levels are defined by limitations on parameters, 
sizes, etc.


At 07:58 AM 9/2/2004 -0400, Karl Dubost wrote:
>         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 15:19:05 UTC

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