Raphael wrote: > On Tue, 5 Feb 2002, Dave Neary wrote: > > Raphael Quinet wrote: > > > [...] Note that it is important > > > that each individual item in the EXIF data is converted to a > > > separate GIMP parasite instead of importing the whole EXIF data in > > > one big chunk because [...] > > > > I'm not sure I agree with you here... I thought the matter was > > closed and that we were in agreement last December, but as I > > understand it there is no reason to have more than one parasite for > > exif data (or if you prefer a more generic metadata parasite which > > encompasses a superset of exif). > > There are several reasons for using individual parasites for each part > of the EXIF data instead of using a single parasite including the > whole structure: [snipped points] Your points all have merit. My problem is now, and has always been, that a parasite per piece of data would mean adding an extra 50 or 60 parasites which would be relatively persistent. That makes things pretty complicated, to my mind. Instead we could store the whole metadata in a nice format (say as xml?) as one parasite, and have it parsed in one place. Then people who want to use bits of the metadata would just use the bits they wanted, and ignore the bits they didn't (in terms of file formats this certainly doesn't contradict your concern about things being copied blindly - it amounts to the same thing as your opinion that those things should be ignored blindly). I think one structure, defined in one place, makes the handling of metadata cleaner. I'd equate it somewhat loosely to the move from a number of preferences to one preferences structure which we had a while back. I think your concerns about passing around data which will eventually be ignored, and incurring an overhead through parsing one big object into something meaningful, are real. I think they could probably be addressed easily. > > My understanding, from what Sven and Mitch told me back then, was that > > a part of a parasite could quite easily be modified independant of the > > rest. > > The parasites are just untyped blocks of data, so a plug-in could > certainly copy everything, modify a part of the data and then > re-attach the updated parasite to the image. But again this would > assume that all file plug-ins that want to use (a part of) the > metadata are able to parse the EXIF block. I would prefer to avoid > this requirement. And herein lies the crux - one object which is parsed by any object that wants to use bits of it, or multiple objects which are the bits. I think the cleanliness of having everything in one place is appealing. I think it could make things less convoluted for places thgat use a lot of the data, and not too bad for places that only use a little. Maybe we'll never agree :) Then again, maybe someone else will offer an opinion, and one of us will realise how wrong we were? Cheers, Dave.
