mapivi

As mapivi needs to have a jpg one might consider using dcraw to get such a
jpg from the raw for preview (a comment in mapivi code refers to nefextract
but that would only work for Nikon; dcraw handles a lot more formats).
According to the man-page of dcraw:

[...]
-e Extract the camera-generated thumbnail, not the raw image. You'll get
either a JPEG or a PPM file, depending on the camera.
[...]

Thus, using

dcraw -e myfile.nef

produces a neat lower quality myfile.thumb.jpg out of the raw. The nice
thing is it does so in almost no time! Its dimensions are even almost the
same as the real jpg (4288x2848 vs. 4352x2868 on my D90) so it can be
considered usable at least for thumbnail generation, indeed. Calling dcraw
against the plain raw to create a ppm out of it seems not advisable as the
result is actually pretty bad compared to the thumbnail if dcraw does not
get suitable parameters. Besides, developing the raw to ppm that way also
takes quite some time while extracting the thumbnail is really fast.

A workflow for mapivis importer with raw support might now use dcraw to
fetch those thumbnails (imagemagick could be used to convert ppm to jpg in
case necessary) and use them to make the raws accessible within mapivi. If
the current state should be preserved, it would be enough to rename
myfile.thumb.jpg to myfile.jpg and one is done. This has the drawback that
the user does not get any feedback from the thumbnail that it is in low
quality and that actually the raw should get processed beforehand as mapivi
can not disinguished the finalized jpg from the intermediate thumbnail.

Therefore it seems advisable for mapivi to learn to deal with .thumb.jpg
and signify the user by some means that work has to be done here. The
existence of .thumb.jpg could be used as a marker. Once the raw is
processed to jpg mapivi could detect the existence of .jpg, regenerate its
internal thumbnail based on the .jpg and remove the .thumb.jpg. IMHO this
would give a pretty nice raw workflow support already.

Still, for a work around that would do it _today_ one could e.g. mount the
camera via gphotofs or use the card in some card reader, fire up a small
script that:
- transfers the raws to some tempdir
- calls dcraw -e against them
- renames the .thumb.jpg to .jpg.
Then one could easily run mapivi's importer against the temp dir fetch the
photos from there and proceed. Setting mapivi to delete the source files
would even do automatic cleanup of the tempdir.

To integrate raw conversion I played around with invoking a raw converter
from within mapivi by means of a plugin. This is actually pretty easy as
one could just start out from the test-plugin and add a simple system()
call to the raw converter instead of just printing out the file name given
to the plugin. This worked pretty well with either ufraw and Rawtherapee as
converters. The main drawback here is that mapivi seems to wait for the
plugin to return which can take a while if I put up a number of raws in
Rawtherapees batch queue or whatever. It would be nice (not only for this
case) if one could shell out within a plugin such that mapivi does not wait
for the external to return. Either this is not possible or I did not find a
hint in the docs.