[Niccolo]

My photo collections are mainly made of 4:3 landscapes and fews 3:4 portraits. I wish to view them on a 16:9 screen using Kodi (v.17.6 on Raspberry Pi). I hate black borders, so I wish to manually choose the zoom and pan of each shot and then activate the slideshow.

The preferred solution can be:
1) View each image, zoom and pan as required, press an hotkey to save the current viewport into an SQLite database (preferably into the same folder of the photos, so that it can be shared, or into the Kodi database).
2) When the slideshow is activated, if the Ken Burns effect is disabled, use the preferred viewport from the SQLite db for each picture.

One alternative can be to have a slideshow based on a m3u-like list, so we can combine images from different folders, specify a custom viewport and time for each image.

Another alternative: is it possible to use an external program for the slideshow? I found this program which does nearly perfect what I need: https://github.com/danboid/shufti

[Karellen]

Not possible. There is no Pictures database. It is simply a file view mode.

But certainly sounds like a good Feature Request so I will move you there.

[Niccolo]

After some months of studying and coding, I wrote a script add-on to do what I need. You can download it from here: script.picture.photo-frame. Basically it is an add-on that you launch from the Context Menu over a pictures folder, it will search a playlist.m3u file, which should contain something like this:

IMG_6602.JPG|4000x2250+0+332
IMG_6605.JPG|2971x1671+796+628
IMG_6606.JPG|4000x2250+0+442
IMG_6610.JPG|3810x2143+90+387

It does not have any fancy transition effect, just a timer or manual slide change.
You can also launch the script over an .m3u playlist: every picture listed in it will be searched starting from the same folder, so accessing subfolders is possibile.
You can prepare different playlists for different screen width/height ratios, e.g. playlist_16x9.m3u, playlist_4x3.m3u, etc. and save them in the same folder. The add-on wil use the best matching one, based on the actual window size.