keeps repeating images even though large pool of images and i THINK settings are correct

[therealrobster]

I have the following launch command to start up the photo frame on my raspberry pi:

DISPLAY=:0.0 XAUTHORITY=/home/pi/.Xauthority feh -Z -F -z -Y -D 10 --auto-rotate /home/pi/Pictures/piPictureFrame/

I have ABOUT 1500 photos in the folder it's grabbing from and I am seeing repeats within an hour or two. On restart, the same photos are GENERALLY regularly repeating again after time. With 1500 + images I can't see how that can happen.

Can anyone recommend what I'm missing or doing wrong to have it keep selecting the same images?

I would have thought with those command variables it would be refreshing new random images each time but it's showing the same images just too many times every hour or so.

[fire-eggs]

Those settings look fine to me. Repeats within a short time doesn't seem right.

The code to randomize the list (-z) appears to be a valid random shuffle [gib_list.c \ gib_list_randomize].

A delay of 10 seconds would mean a list of 1500 images will "cycle" in about 4 hours. On cycle, the list is re-randomized, which means it is possible an image can show up "again".

Other possible explanations I can think of:

• your 1500 images are include sub-folders, and you need to use "-r" to pull images in recursively
• the list of images feh will actually load is less than 1500 (not supported image formats)
• you have duplicates in your image list

You could test the first two possibilities with the -U option:

feh -U /home/pi/Pictures/piPictureFrame/ | wc -l

will tell you how many images feh will actually load. [If the actual list is (e.g.) 720 files, then the slideshow cycle is 2 hours and the likelihood of seeing a "repeat" image after 2 hours is much higher].

I don't like repeats in a random list either, so I'm going to investigate if the list randomizer is truly random.

[splitbrain]

I can confirm the problem. Even though the images come up in a different order on every start, it seems always to be the same few images. It's as if feh only loads the first X images and shuffles them, but ignores the rest.

Background: feh is triggered by a motion sensor and only runs for as long as there is motion in front of the frame. So it is frequently restarted. With a large number of pictures I would expect to see completely different pictures on every restart. But that's clearly not the case.

pi@picframe:~ $ feh -U photos/ |wc -l
1024
pi@picframe:~ $ ls -1 photos/ |wc -l
1034

[fire-eggs]

We'll need to know which version you're running (feh -v).

[splitbrain]

$ feh -v
feh version 2.18
Compile-time switches: curl exif xinerama

The more I think about it, the more I believe it might actually be just human perception and not an actual bug in the RNG. Is there a way to let feh just print the randomized file list? That way it would be easy to verify.

[fire-eggs]

feh version 2.18

feh version 2.18 is ancient. Several changes have been made to increase randomicity since that version. [Especially feh 2.28]

Raspberry Pi OS bullseye has feh 3.6.3 and I'm using 3.3 on Linux Mint.

Is there a way to let feh just print the randomized file list?

According to the man page for 3.3, there are two ways:

1. the -U switch outputs the list
2. pressing the 'L' key during the slideshow will produce a copy of the file list

In my testing, the file list from both approaches appears to be randomized.