I was looking at the sizes of album art on bandcamp and testing what sizes result from changes to the image URL suffix. Here are the results of my testing for the URL:
https://f4.bcbits.com/img/aNNNNNNNNNN_M
where N… represents a number specific to the album, and _M is the number I am changing:
_0 full size original format
_1 full size PNG
_2 350^2 JPEG //cropped to 1:1 aspect ratio
_3 100^2 JPEG //cropped to 1:1 aspect ratio
_4 300^2 JPEG //cropped to 1:1 aspect ratio
_5 700^2 JPEG //cropped to 1:1 aspect ratio
_6 100^2 JPEG //cropped to 1:1 aspect ratio
_7 150^2 JPEG //cropped to 1:1 aspect ratio
_8 124^2 JPEG //cropped to 1:1 aspect ratio
_9 210^2 JPEG //cropped to 1:1 aspect ratio
_10 1200^2 JPEG //original aspect ratio, no upscaling
_11 172^2 JPEG //cropped to 1:1 aspect ratio
_12 138^2 JPEG //cropped to 1:1 aspect ratio
_13 380^2 JPEG //cropped to 1:1 aspect ratio
_14 368^2 JPEG //cropped to 1:1 aspect ratio
_15 135^2 JPEG //cropped to 1:1 aspect ratio
_16 700^2 JPEG //cropped to 1:1 aspect ratio, will upscale
_17 N/A // Error 404
_18 N/A // Error 404
_19 N/A // Error 404
_20 1024^2 JPEG //original aspect ratio, no upscaling
_21 120^2 JPEG //original aspect ratio
_22 25^2 JPEG //cropped to 1:1 aspect ratio
_23 300^2 JPEG //original aspect ratio
_24 300^2 JPEG //cropped to 1:1 aspect ratio
_25 700^2 JPEG //original aspect ratio
_26 800*600 JPEG //cropped to 4:3 aspect ratio, will upscale
_27 715*402 JPEG //cropped to 715:402 aspect ratio, will upscale
_28 768*432 JPEG //cropped to 16:9 aspect ratio, will upscale
_29 100*75 JPEG //cropped to 4:3 aspect ratio
_30 N/A // Error 404
_31 1024^2 JPEG //original aspect ratio, no upscaling
_32 380*285 JPEG //original aspect ratio
I have only tested to _32, but I hope this will be of use to someone.
Note that if you’re getting the images for uploading to Cover Art Archive, please use the _0 version.
Do you have any examples of this? I use the “bandcamp helper” script all the time which provides a link to the _1 version which I then change to _0. I haven’t yet found a Bandcamp release where _1 wasn’t PNG (the filename says .jpg, but the actual file is PNG) and _0 has also always worked.
I didn’t keep a track of all concerned releases unfortunately, but i import a lot of Bandcamp releases, and as you know i maintain Bandcamp importer, so i just report minor quirks i encountered.
In general, _0 is working but, last summer, i had to patch Bandcamp importer to use _1 because some _0 images were truncated (only when original was a PNG, near the bottom a band of 20 or 30 pixels was missing, https://github.com/murdos/musicbrainz-userscripts/commit/044037ab498445ec0a6f2142777adf11f0ed60b4) while the _1 was correct. I decided to patch as soon i noticed the problem before editors started to upload truncated images (because it wasn’t easy to notice), and because uploading a PNG to CAA is still better (even if original image is a jpeg).
I just tested those again, and apparently it was fixed on Bandcamp side, _0 and _1 are identical now.
When it happened, i did tests using different downloaders, and different systems/machines and it was an issue on Bandcamp side for sure (perhaps a web server configuration issue).
About the fact some images _1 not being always PNG it happened few times, but not since months, i have no track of those.
I guess those issues were just temporary, but hard to know if all releases were fixed.
