pyexiv2-developers team mailing list archive

[Olivier Tilloy <olivier@xxxxxxxxxx>]

Hi Damien,

On 2010-01-27, Damien Moore <damienlmoore@xxxxxxxxx> wrote:
> Hi Olivier,
>
>  >It fully supports reading from sidecar files, but apparently has a
>  >problem writing back the modified data.
>
> well, reading is a good start. how about reading from one file (either 
> sidecar or images) and writing the data (perhaps with changes) to a new 
> sidecar file?

That's not implemented yet, but would be nice to have indeed. Currently 
all pyexiv2 offers is writing back the metadata in-place.
Can you file a bug report to track this feature request?

>  >This raises no error, however when inspecting the file afterwards, the
>  >value for Xmp.dc.creator is still 'John Doe'.
>
> I guess it should be possible to test this with the exiv2 command line 
> tool(?)

I've done some tests and I'm a bit confused about the results, however 
they are consistent from pyexiv2 to exiv2 (the command line tool), which 
is somewhat reassuring.
Writing single values (XmpText) works fine, with exiv2 and pyexiv2, to 
image files and to XMP sidecars.
However writing complex values (Lang Alts, sequences, ...) works only on 
image files, not in XMP sidecars. I'm not sure whether this is an 
expected behaviour in exiv2, I'll investigate that further.
If anyone who has a better understanding of how XMP sidecars work can 
explain that, I'm eager to learn, and adapt pyexiv2 if that can be done.

Cheers,

Olivier