Odd behavior with Extended File Properties

[Lou O'Quin]

First the background:

 

We have a Windows 2003 Server, holding, among other things, about 100,000 TIF document files.  In order to ensure that our Sharepoint server properly indexes the documents, we copy certain of the TIF tag data to extended file property fields automatically, as a part of a document "check in" process.  We use dsofile.dll, downloaded from Microsoft, to maintain the extended file properties (which are stored as alternate data streams.)  (We COULD enter it manually from the summary window of the file properties as well.)  The summary fields we update include Title, Subject, Category, Keywords, Comments, Source, Author, and Revision Number.   Each file then has at least two alternate data streams, holding the summary data and category data.

 

As a result of this check-in process, we are able to verify tag presence simply by looking at the file properties: Summary Tab from any workstation.

 

This is the problem:  For the last two+ years, we've been running the check-in process from several Windows 2000 workstations.  As a part of our routine PC replacement process, we've recently replaced one of these machines with a Windows XP Pro machine.  Now, the Windows XP machine cannot see ANY of the file property summaries that were entered with the Windows 2000 machines, nor can the Windows 2000 machine see ANY of the file property summaries entered by a Windows XP machine.

 

Does anyone have any ideas as to the cause of this, and how we can address the problem?  Thanks in advance

[Rohan Salt]

Lou,

We have had a similar experience with Jpg images and it MAY be related. In
our case we where adding meta data (title, author, comments, keywords etc) to
Jpg's and trying to get them to be indexed correctly by index server on
win2003.

What we discovered was that WinMe, WinXp and Win2003 introduced support
digital cameras, via something called GDIPlus. These you-bute cameras can
store not only the images but details about when, how and on what hardware
the image was taken as part of the image itself. On Platforms that support
gdiplus, setting image properties via right click properties for Jpgs no
longer save the meta data to the OLE extended Properties fields but rather
store the details in the actual Image file in EXIF format. MS have created
"their own" EXIF Property ID's to store the details they would normally store
in the in the OLE Exteneded Properties.

The long and the short is that for JPGs if you right click and select
properties on a win 2000 machine it will set them in the OLE extended
properties fields . Do the same in Me/XP or 2003 and it will set EXIF
properties in the actual image. DSOFile only sets OLE extended Properties so
the XP machine wont see the properties them coz it looking in the wrong
place.

We ended up cooking up come code to extract the EXIF properties from the
JPGS but its a god dam nightmare! As part of doing the reseach for this , we
came across numerous references to saving properties within tif images as
well as jpgs. This kind of sounds like you problem.. if so, you probably end
up needed to create a little viewer program using DSOFILE to work on the XP
machines.

We also worked out that the Ifilter for jpgs is on win2003 now looks at the
EXIF parameters not the OLE Extended Properties when indexing.. I suspect
that future versions of sharepoint may suddenly stop looking in OLE
Properties in favour of EXIF Properties for TIFs. This is certainly SEEMS to
be the case between win2000 server and win2003 server for jpgs!.

Hope this helps!

Rohan Salt
Director
Hillcrest Computer Services