Some of my MP3s do not display properly in my car. While most are fine, there are some older files that I have whos album art is about half the size they should be -- they do not fill up the screen as they should. Fount MP3tag, and started editing away, replacing those small ones with larger ones. Did a few dozen of the ones on my flask drive, took the drive out to my car, played a file, and there is no album art at all. Every other one that I tried was the same. The files that I didn't work on had no issues -- just the ones I replaced.
What kind of files are we talking about? MP3? M4a? Flac? WAV?
What kind of tags are in the files? APE? ID3v2? ID3V1?
Are the files OK (which means have you checked them with at least one of the tools linked here: How to check files for errors?
And OK does not mean "they play" but that the integrity has really been checked with the tools.
There are car players that search the internet on their own for covers. Sometimes they find some, sometimes they don't.
Use the forum search function with the search words "car", "Cover", "art" and look through the threads.
I found at least 4 dealing with the same topic, unfortunately, none came back with a solution, so apparently the problem solved itself.
They are mp3s with ID3v2 tags. It may very well be the resolution. 2k gives a small picture (about half the physical size it should be). A recently downloaded album has an art resolution of 27K and displays properly. Another has a resolution of 177K, and does NOT display at all. How do I change the resolution?
That is not the resolution but the memory space that the picture takes.
You have to test yourself if the limitation is indeed the resolution or just the size of the memory.
MP3Tag shows you both. i.e.
Size: 87 KB
For testing just take a photo which today usualy has a high resolution.
Then load it i an image editor (i.e. Irfanview) and decrease the resolution step for step and embed these steps in the mp3-file.
If you decrease the resolution the memory space will decrease too. But you can take influence on this in changing the compression factor. Because of this you'll have to take a close look what really matters for your player:
The amount of bytes or the resolution.
Got it. Most of the Album Art I've downloaded has been around 500x500 or so, with the occasional higher.
What makes this even more interesting is that while my flash drive has sat in my car since Monday morning, this morning everything seemed to be working as it should. In one folder where I changed the picture, it displayed just fine while in another folder where I hadn't changed it yet the album art for the same mp3 was still small.
What, from your experience, would be the optimal resolution? Between, say, 300 and 500?
Maybe your car player uses a cache for the cover-art?
Well, it still seems not to be clear whether the resolution is the problem. There are other possible reasons, even some really absurd ones like this the user ryerman wrote of:
You have to decide for yourself which resolution suits your needs.
I don't have a car player (in fact I don't even own a car). So to me it is does not matter which resolution is sufficient for a rather small display.
I can tell you my decisions for cover-art:
Because I don't want my mp3s get too big just because of non musical content I decided to use jpgs with a resolution of 800x800, take only the front-cover to embed and a slightly higher compression. That results in pictures of about 50-150 KB size depending on the picture content.
I take pictures with the highest resolution I can find on the internet (with the software AlbumArtCover) as source and decrease the resolution to 800x800 and compress them myself. This results in better quality and smaller size than original found 800x800 pictures.
I do this because to me it makes no sense to decide to use mp3-compressed songs with about 3-8 MB size and then blow them up with nice to have but not essential cover-art to the double size with high-resolution cover-art.
But as I am centered on albums and not single songs and all my songs are in album-folders I store the high-resolution art-work as files in this folder and not only the front-cover but also additional cover-art (back-cover, booklets, CDs) as far I can find it.
So I am able to change the embedded cover-art to a higher resolution if I change my mind about the optimal resolution some time in the future.