Re: [Tracker] fd.o compliant thumbnailing

[Erlend Davidson <E R M Davidson sms ed ac uk>]

Jon Phillips wrote:
> On Tue, 2006-11-28 at 18:57 +0000, Jamie McCracken wrote:
>   
> > Edward Duffy wrote:
> >     
> > > I know this isn't a high priority item, but here's a patch that makes
> > > tracker's thumbnail support follow the fd.o spec.  It uses the
> > > $HOME/.thumbnails directory, so it'll work along side nautilus,
> > > thundar, and konq.  It will not overwrite up-to-date thumbnails, but
> > > the File.SmallThumbnailPath metadata item will be filled in correctly.
> > >
> > > Currently, it only works for "normal" size, or 128x128, thumbnails.
> > > This is because tracker defines "large" as 640x640 while fd.o spec
> > > defines it as only 256x256.  Maybe we could create a new directory,
> > > called "preview", for these extra-large thumbnails.
> > >
> > > The patch also removes the hard-coded disabling of thumbnails, so
> > > you'll be able to enable it via the EnableThumbnails key in
> > > tracker.cfg.  If everything is working right, nautilus should start
> > > showing thumbnails for your OO.o documents (currently the only
> > > thumbnail generator we have, that nautilus doesn't).
> > >
> > > Also, this puts a hard dependancy on libpng.  It's needed because the
> > > file's URI and MTime need to be embeded in the thumbnail file so it
> > > can be tested for validity.  I doubt this should be a problem though.
> > >
> > >
> > >       
> > Great work!
> >
> > now added with a few minor changes.
> >
> > We only extract a 128x128 so I have disabled the big thumb for now
> >
> > Im not sure if we need a command line option for thumbnailing. I have 
> > not tested it fully as I cant seem to persuade it to thumbnail but then 
> > again maybe its because my thumbs are up to date!
> >
> > please check cvs (update with new directories from cvs) properly thumbnails
> >     
>
> This is great...so if you submit one more nice patch like this one, we
> will support you getting direct cvs access to this project.
>   
What is tracker going to do about support for thumbnails?  The 
file-manager Thunar (http://thunar.xfce.org) handles thumbnailing in a 
freedesktop.org compliant way, could you just use its mechanism for 
generating thumbnails?  Thunar has built-in support for many common 
formats (this is as a part of thunar-vfs) like pdf, images supported by 
gdk-pixbuf and all the gconf thumbnailers.

I am currently writing a host of thumbnailer plugins for thunar 
(http://goodies.xfce.org/projects/thunar-plugins/thunar-thumbnailers) - 
these are just short scripts that call external programs (usually 
"convert" from imagemagick).  They are written according to: 
http://thunar.xfce.org/documentation/C/customizing-thunar.html#thumbnailers.  
I think it would be quite easy to use the same thumbnailer scripts in 
tracker.