What are the optimal cover art (artwork) settings (size, quality) for folder.jpg

  • 21 December 2018
  • 6 replies

Having a few issues when browsing 'Music Library > Albums' on PC and Android App:
1 - Album thumbnails are slow to load
2 - Occasionally thumbnails fail to load (timeout?) despite folder.jpg being present (and navigating into album always forces thumbnail to show correctly)
3 - Thumbnail is never show despite folder.jpg being present.

I believe all my issues are because the artwork is too high quality. Images in the hundreds of Kb are taking too long to load, and when I browse the complete album catalog, this can cause some to not show at all. My point 3. is because some of my images are over 1024x1024 pixels in size (although comment in below link refers to embedded content):

So my question and reason for this topic. What is the optimal artwork size for Sonos please? Are there any links to docs/specifications/wikis etc.? I resized some images to 200x200 pixels, which resulted in much faster loading, probably because they where now only ~25Kb in size.

I guessing Sonos s/w resizes artwork on the fly (I played with ImageMagick in a past life!)? Is there a size setting which would avoid resizing, for at least one of the browse catalogs, PC or App, for example?

This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

6 replies

Interesting article over on Sonos Labs, but I'm unsure if this helps me at the moment:
Userlevel 7
Badge +21
I tend to stick to 500x500 and jpgs compressed to 25-50 kb. That looks decent on my largest tablet screen.
I'd suggest resizing down to 600x600 max, aiming for no more than 300kB. There are also websites which can recompress JPGs, sometimes with excellent size reductions.
I played with the resolution settings and for me 200x200 offers the best in terms of quality/performance.

I create a GNU make file to automate the process, which some may find useful. I store my music on Synology NAS and administer it from Windows PC. I renamed all my high quality cover art to "original_hi_res.jpg" and allow the make file to build the 'folder.jpg' images using ImageMagick. This approach allowed me to modify the resolution setting and apply to the whole library. Going forward, it also handles incremental changes to my library (adding new music) without having to rebuild all thumbs:


CONVERT="C:/Program Files/ImageMagick-7.0.8-Q16/magick.exe"
SSH="C:/Program Files/PuTTY/plink.exe" -load admin@ruby

T1PATHS=archive old shared current

# Find all root artist/album folders
T2PATHS=$(foreach t1folder,$(T1PATHS),$(patsubst %,M:/$(t1folder)/%/original_hi_res.jpg,$(shell $(SSH) ls //volume1/music/$(t1folder))))

NEW=$(patsubst %/original_hi_res.jpg,%/folder.jpg,$(T2PATHS))

%/folder.jpg : %/original_hi_res.jpg
$(CONVERT) $< -resize 200x200\> $@

.PHONY : all
all : $(NEW)
# Copy folder thumbnails down to CD1 CD2 folders if present
$(SSH) find $(patsubst %,//volume1/music/%,$(T1PATHS)) -type d -name 'CD*' -exec cp -p {}/../folder.jpg {} \\\;
@echo Thumbs up-to-date

.PHONY : clean
clean :
$(SSH) find $(patsubst %,//volume1/music/%,$(T1PATHS)) -type f -name "folder.jpg" -exec rm -f {} \\\;
I played with the resolution settings and for me 200x200 offers the best in terms of quality/performance.
Much too low a figure IMO, and I would seriously advise that a user shouldn't waste their time with that resolution.

When I first ripped my CDs over 10 years ago, I was glad to find any suitable artwork online, and at that time the unchallenging display target was the CR100 (plus a PC). 200x200 may have sufficed back then but as soon as I moved onto higher resolution tablets (Nexus 7 is 1920x1200) the coarseness was well and truly exposed. I ended up replacing virtually all of my album art.

In terms of retrieval performance, what matters is the size of the file. Keep that within sensible bounds and artwork at, or close to, the native resolution of the display device can be displayed satisfactorily.
Userlevel 7
Badge +21
200x200 is a good thumbnail or smaller phone screen size but look at the Play screen with the queue hidden on your largest screen and count the dots to see what size the album art is being shown at. Don't go much below that to avoid fuzzies.