Hi folks,
On Mon, 27 Oct 2003, Guy Rixon wrote:
> This is vapourous, but...
>
> The Data Format Description Language Working Group (DFDL-WG) of GGF is
> prodcing an XMNL vocabulary that will describe binary data. Essentially, it's
> a language for recording structural metadata in XML. Using this, one goal is
> that a DFDL-aware programme can search the DFDL using XPath and obtain from
> this some kind of reference (pointer, byte offset, whatever) into the actual
> data.
>
> None of this is going to happen soon, but it may come to pass that we _can_
> search binary with XPath.
This is slightly less vaporous than Guy implies. One of the prototyping efforts behind the development of the DFDL standards is a project called BinX (for Binary in XML) which is being developed by the eDIKT team at the National e-Science Centre here in Edinburgh.
BinX is basically an XML language for describing the structure and content of binary data files. I've been working with the eDIKT team on an astronomical testbed for BinX in recent months. This has been pretty basic so far - just using BinX as a means of converting between FITS binary tables and VOTable - but it is intended to develop further.
The eDIKT team plan to incorporate some level of XPath support into the next release of the BinX library. The basic idea is that the BinX description of the binary data file provides what can be thought of as an implied XML representation of the data, so that one can then use XPath to navigate through it. Work on implementing this is just starting, I believe.
As Guy said, it is likely to be the GGF DFDL working group which develops the ultimate standard for this, but BinX is driving the prototyping work, and is likely to morph into one of the reference implementations of DFDL in due course.
I've been meaning to write up a note on BinX for AstroGrid for a long time, and should do this in the next couple of weeks. I'll post the URL for that note to this list when I do. In the meantime, further information on BinX can be found at www.edikt.org/binx and a presentation on it can be found at www.nesc.ac.uk/talks/226/wen.ppt. This latter presentation includes a couple of suggestions as to how BinX could be incorporated into VOTable.
In addition, I'd be very happy to discuss input from the VO community into further development of BinX, either on this list or offline - I was going to describe all this in the VOTable session of the post-ADASS interoperability meeting, but, unfortunately, I had to cancel my trip to Strasbourg at the last minute.
cheers
Bob Received on 2003-10-28Z12:57:29