[ EDIT August 2014: I have just discovered that iTunes now routinely converts artwork embedded in MP3 files from JPG format to PNG format. I have therefore written a new post to replace this one, giving instructions which worked definitively for every single MP3 file I own. This post has been left up for historical interest, but I strongly suggest you check out the new one instead because it works more effectively.
I’ve recently got a Mark 7 Volkswagen Golf S, which includes the standard “Composition Media System (CMS)”. This has an SD card slot in the glove box, allowing you to play MP3 files from anything up to a 2Tb SDXC card. That’s great in theory, but in practice it’s taken me nearly a week to get everything up and running. Here are the lessons I’ve learned…
The stereo will only read a maximum of 1000 sub-directories within any one directory. If, like me, you have your music in folders by artist name and there are more than 1,000, you’ll have to move some into another folder. If you do have more than 1,000 folders then they will still be organised alphabetically but the list will just finish at the 1,000th folder and you won’t be able to scroll down any further.
If you use a Mac, you’ll find that it scatters files beginning with a dot in their name across the folders, e.g. .DS_Store The Golf doesn’t like this, and so you’ll need to get rid of them, otherwise it will just skip over any directory with them in. If you use a Mac then you can use the Terminal to do so – open a new Terminal window or tab, and ‘cd’ to your SD card. It will be be at /Volumes/[name of card]. Then run a ‘find’ command to look for all the files:
find -type f -iname ".*"
If that looks like a sensible list and you want to delete them, run the find command again but include the ‘-delete’ flag at the end.
find -type f -iname ".*" -delete
If you’re on Windows, you can delete the files at the Command Prompt using the command below (obviously you’ll need to change to the relevant drive letter first):
del /s /q /f /a:h .*
Finally, both of those commands can be modified slightly to also delete any standalone album art you have. Your album art should be embedded in your MP3 files, so you can delete anything called, for example, folder.jpg or cover.jpg to free up space on your SD card and fit more music on. Examples for Mac and Windows respectively would be:
find -type f -name "folder.jpg" -delete
del /s /q /f folder.jpg
The album art embedded in your MP3 files must be a maximum of 400px by 400px. I initially tried re-sizing to 500px square but that didn’t work. To do the resizing I used a program called Sanse MP3 Art Resizer, which I found thanks to this blog post. Unfortunately it’s Windows-only, but is free and worked well for me. Note that to resize to 400 pixels square you’ll need to amend the “Target” of the desktop shortcut to include the following at the end: SanseMp3ArtSizer.exe /400/100
Radio Station Logos
The user manual states that radio station logos can be up to 400px by 240px, but my car wouldn’t read files at that size. If yours does then someone on golfmk7forum.com has made a set you can download. Instead, you can download ready-made icons from Volkswagen at 160px by 120px, or I have made a set of nice sharp PNGs at the same size which seems to work nicely. Whatever size you choose, they’ll always look a bit fuzzy because they are always resized – the icon for the selected station is bigger than the others, so there’s always something that isn’t at its native resolution.
Finally, then, this is the order in which I did things to make sure I had all my music available with album art, and radio station logos.
- Format SD card as exFAT.
- Copy radio station logos to SD card, and then set them up on the car stereo as per instructions in the radio manual.
- Format SD card as exFAT again.
- Copy music across to SD card.
- Organise so that no one folder contains more than 1,000 subfolders.
- Run Terminal or Command Prompt command to delete all standalone album art files.
- Run album art resizer to ensure that all album art embedded in MP3 files is 400px by 400px or smaller.
- Empty Trash or Recycle Bin.
- Run Terminal or Command Prompt to delete all ‘dot files’.
- Eject card.