Long ago, I had to keep the size of cover art down, that it would display on my awesome Sansa Fuse media player. I stuck to something like 140 × 140 pixel JPEGs, which was usually less than 20 KB.
A while ago, I started using 300 × 300 pixel JPEGs, which I imagine is very conservative. I've held on to the notion that the size of the cover art might affect playback, though it probably does not—I'm just silly. My Sansa Fuse gave up the ghost long ago, and I play everything with my phone.
While larger cover art likely causes no issues with modern equipment, there must be a point at which the physical size of cover art exceeds display capability, and art is rescaled downward by our hardware? There exists a resolution it is pointless to exceed given the limitations of current hardware?
What is a good size today? 600 × 600? 1,000 × 1,000? Higher?
Great question. I've inched larger myself over the years. 300x300 was my go-to for years, mainly for storage concerns. Now I use 600x600 for almost all covers, if I'm newly tagging something. Storage is no longer a concern (thank you 4TB SSD).
I used to listen to most of my music while driving, so covers were a big deal (my car displayed them on the screen). I liked seeing them. Now 99% of my listening is done thru Bluetooth (phone to ears), and I rarely see a cover.
Good old iTunes at one point had a minimum of 600px² for music to be uploaded to their site. I believe this has started to creep up to 1000px² (maybe more?) but I don't know if this goes back to older files that are still on their site for purchase now.
I think as the file sizes for lossless media that has moved to 24 and even 32 bit depth and very high sample rates, these picture sizes are still small in comparison. This probably wasn't true back in the earlier, lossy, high compression mp3 days when storage was at a much higher premium.
Agree. I used to use "folder.jpg" and not embed an image, just to save that 50K extra tag, times 10 or 20 MP3 files. Over the last couple years, I removed all of them, and now use 100% embedded images.
1 album/folder, folder.jpg in it, 200×200 pixel, max 64 KB (usually much less); to see folders as images (when i want) in Total Commander. +1 folder.jpg for all parent (=artist) folder.
(+ all other images of the album, in the album's folder)
From the other hand, about the music files size: i never store bigger, than 48kHz/16bit music files. If you can not identify (=differentiate) a file in blind test, that all is unnecessary quality.
This is subjective of course, dependent on the quality of the original source material and the playback hardware. However one could argue that regardless, there is at least a value in maintaining archive quality.
As your example shows, requirements can change over the time. So I would say: the best quality available at the time of ripping.
Otherwise you are forced to do it all over again once your environment changes.
This "embedding" is new to me, unless this describes what MP3Tag does with album art. If MP3Tag is "embedding," my apologies. I never labelled the process; I just did it.
I am now in the habit of saving the largest bitmap I can find for any given album in the associated folder as "cover.jpg" and resampling that down to 300 × 300 pixels at 72 dpi; this I save as "folder.jpg" and use it to add cover art to every song with MP3Tag. I save the "folder.jpg" in the album folder as well. I've started thinking that I might go to 600 × 600, as current technology seems to have no problem with larger images. Though I do wish my car displayed album art. That would be cool.
I used to delete the JPGs once I added artwork to songs, but now I keep them—mainly because it is becoming more difficult to find images for the more rare albums these days. If I ever want to raise the bar, as it were, the old artwork will be there for me.
It there is no technical reason why you need a file with this name, I would suggest that you save the file with the name consiting of %album% and %_cover_type%.
With such a name you can identify the contents without the need to open it in a graphic tool if the original folder is lost or renamed.
Also, you avoid that picture files from different folders but different content get overwritten when merged.
that is why I asked if there is a technical requirement.
If you do not follow the vanity to see pictures on folder icons then the file folder.jpg is absolutely superfluous. No decent player relies on an external file in a folder to show a picture if there is an embedded one.