Meta data available to filters?

Hi!

If I set up a filter, is there a way from my filter script to know the name or identity of the file that I am processing?

I get the data on standard in and output the changed data on standard out, but is there any way to get access to meta data?

I find the documentation on filters a bit terse. Once I figure out how they actually work, I may be inclined to send a documentation patch. A minimum would be to document their existence on the git-config manual page (with reference to gitattributes), it took me some time to find it :-)