- From: Lofton Henderson <lofton@rockynet.com>
- Date: Thu, 02 Sep 2004 09:18:55 -0600
- 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): http://lists.w3.org/Archives/Member/w3c-svg-wg/2004JulSep/0792.html 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. -Lofton. At 07:58 AM 9/2/2004 -0400, Karl Dubost wrote: >http://www.m4if.org/resources/mpeg4userfaq.php#Profiles > > > 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