[X3D-Public] X3D Compressed Binary Encoding, requirements review

[Don Brutzman]

Steady work has continued our discussion and refinement of X3D 
Compressed Binary plans for 2013.

Leonard and I have updated the wiki page to document progress and 
discussions in recent weekly meetings.

	http://web3d.org/wiki/index.php/X3D_Binary_Compression_Capabilities_and_Plans

We now seek feedback on the suitability of our original Requirements for 
X3D Compressed Binary Encoding that were successfully used a decade ago. 
  They still look pretty darn good.  Further additions and improvements 
and suggestions are welcome.

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http://web3d.org/x3d/binary/X3dBinaryRFP.html#Requirements

"The X3D Task Group has established the following overall requirements 
for binary encoding:"

* X3D Compatibility. The compressed binary encoding shall be able to 
encode all of the abstract functionality described in X3D Abstract 
Specification.
* Interoperability. The compressed binary encoding shall contain 
identical information to the other X3D encodings (XML and Classic VRML). 
It shall support an identical round-trip conversion between the X3D 
encodings.
* Multiple, separable data types. The compressed binary encoding shall 
support multiple, separable media data types, including all node 
(element) and field (attribute) types in X3D. In particular, it shall 
include geometric compression for the following.
         Geometry - polygons and surfaces, including NURBS
         Interpolation data - spline and animation data, including 
particularly long sequences such as motion capture (also see Streaming 
requirement)
         Textures - PixelTexture, other texture and multitexture formats 
(also see Bundling requirement)
         Array Datatypes - arrays of generic and geometric data types
         Tokens - tags, element and attribute descriptors, or field and 
node textual headers
* Processing Performance. The compressed binary encoding shall be easy 
and efficient to process in a runtime environment. Outputs must include 
directly typed scene-graph data structures, not just strings which might 
then need another parsing pass. End-to-end processing performance for 
construction of a scene-graph as in-memory typed data structures (i.e. 
decompression and deserialization) shall be superior to that offered by 
gzip and string parsing.
* Ease of Implementation. Binary compression algorithms shall be easy to 
implement, as demonstrated by the ongoing Web3D requirement for multiple 
implementations. Two (or more) implementations are needed for eventual 
advancement, including at least one open-source implementation.
* Streaming. Compressed binary encoding will operate in a variety of 
network-streaming environments, including http and sockets, at various 
(high and low) bandwidths. Local file retrieval of such files shall 
remain feasible and practical.
* Authorability. Compressed binary encoding shall consist of 
implementable compression and decompression algorithms that may be used 
during scene-authoring preparation, network delivery and run-time viewing.
* Compression. Compressed binary encoding algorithms will together 
enable effective compression of diverse datatypes. At a minimum, such 
algorithms shall support lossless compression. Lossy compression 
alternatives may also be supported. When compression results are claimed 
by proposal submitters, both lossless and lossy characteristics must be 
described and quantified.
* Security. Compressed binary encoding will optionally enable security, 
content protection, privacy preferences and metadata such as encryption, 
conditional access, and watermarking. Default solutions are those 
defined by the W3C Recommendations for XML Encryption and XML Signature.
* Bundling. Mechanisms for bundling multiple files (e.g. X3D scene, 
Inlined subscenes, image files, audio file, etc.) into a single archive 
file will be considered.
* Intellectual Property Rights (IPR). All technology submissions must 
follow the predeclaration requirements of the Web3D Consortium IPR 
policy in order to be considered for inclusion.
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The X3D Compressed Binary Encoding will continue to be a regular topic 
at weekly meetings.  Our goal is issue the Call for Contributions in April.

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman