Random mix not so random...

[Ranokivio]

Hi there,

I have a squeezebox since last year and I am quite happy with it. However, I usually like to listen to my music using the random album mix and I always found the random function not very efficient (i.e the same album will play 3 times in a week while 95% of the other albums won't play once). Is there any other people with the same problem here? Is there a way around? It happens on Windows and on Ubuntu (I have a dual boot). I have less than 10000 songs on my computer (i.e less than 2000 albums). I always use the last stable version of SC...
I know "random" means I could have the same album 3 times in a row once but it happens on a regular basis so there is definitely something wrong.
Any ideas?

[aevans]

I second that. I use my sb3 as an alarm. With SC 7.2 the random mix didn't work so it always defaulted to the 'random 10 tunes' fallback alarm. I found this 100% random and fine. but since upgrading to 7.2.1, the alarm is now fixed but i find i'm waking up to guns and roses every morning! and i really don't have much of their music.

[cjbrooker]

I always found the random function not very efficient (i.e the same album will play 3 times in a week while 95% of the other albums won't play once).

I have noticed a similar thing.

I listen to playlists on random. There are 100's of songs on the playlist but I still find it can repeat songs from the same album every 15 or so songs.

For example if I hear a song from an album it's almost certain that I will hear another song from the same album in a few tracks time while other songs in the playlist are random.

In the playlist I'm listening to at the moment (2000+ songs) I can see that for the only Jimi Hendrix album I have there are 3 tracks within the space of 20 songs in the 'random' playlist. This happens consistently so isn't as random as it could be. However, I do get all of my albums eventually unlike Ranokivio.

I think it has been this way for some time. There must be a problem with the algorithm that is used for random. I know computers are not good at doing 'random' but I'm sure Squeezecenter could be improved here.

Anyone else noticed this or am I being over sensitive?

[EricBergan]

I have noticed a similar thing.

In the playlist I'm listening to at the moment (2000+ songs) I can see that for the only Jimi Hendrix album I have there are 3 tracks within the space of 20 songs in the 'random' playlist. This happens consistently so isn't as random as it could be. However, I do get all of my albums eventually unlike Ranokivio.

I think it has been this way for some time. There must be a problem with the algorithm that is used for random. I know computers are not good at doing 'random' but I'm sure Squeezecenter could be improved here.

Anyone else noticed this or am I being over sensitive?

+1

I have playlists with thousands of songs from almost a thousand albums, yet within the space of 50 songs, will get 2 or 3 each from a couple albums.

I've worked on random algorithms, so I do understand that only statistical analysis will really prove whether it's working or not, but my instincts say there is an error in the algorithm.

I also agree its been there for several generations of server.

eric

[mrfantasy]

Yeah, again, I haven't been able to prove anything statistically significant, but my intuition tells me it's not working. http://forums.slimdevices.com/showthread.php?t=59041

If you look at the Random Mix code it's relying on MySQL's "ORDER BY RANDOM" to return results, so at first blush that would be where the problem is; but there's also a lot of code in there to do the genre matching, duplicate avoidance, and other things that I can't really determine and I suspect there's a side effect coming off that.

I'm curious what the size of your music libraries are. Since it seems there's an effect that only a subset of my library is getting mixed, I wonder if there's a size factor.

[EricBergan]

I'm curious what the size of your music libraries are. Since it seems there's an effect that only a subset of my library is getting mixed, I wonder if there's a size factor.

543 albums, 6519 songs by 293 artists

My common playlists are ~800, ~1600, ~2500 and ~5800 songs.

eric

[cjbrooker]

I'm curious what the size of your music libraries are. Since it seems there's an effect that only a subset of my library is getting mixed, I wonder if there's a size factor.

4540 songs, 340 albums, 153 artists.

Playlists of between 600 and 2000 tracks.

[mrfantasy]

Tried something interesting: Connect to the squeezecenter MySQL instance, and run the query "SELECT * from tracks ORDER BY RAND() LIMIT 10;" and see what you get. I'm getting results that very closely mirror the strange results I get from Random Mix itself, which suggests the problem is, in fact in MySQL's RAND() function. I'm going to pursue that angle a little more.

[tipsen]

I'm also experiencing seemingly "not-so-random" behaviour from random albums with my squeezebox! Apparently other people have been experiencing the same behaviour when using MySQL from PHP:

http://archives.devshed.com/forums/m...m-1427558.html

As far as I can tell from the MySQL manual there is no other obvious way to do this - it is the "correct" solution... :-(

/Tommy

[Chop Chop]

Apparently other people have been experiencing the same behaviour when using MySQL from PHP

Looking at that thread, wouldn't it be possible to use the Perl rand() function to seed the random query in MySQL, whenever a random query is done in MySQL? I know it's not elegant, but hopefully it would give a more random selection.