Montag, 15. April 2013

Playing MP3's on a Navigation Business Radio (BMW E60/E61) - Fixing the skip issue

After burning my first MP3 CD for my BMW e60 I was wondering why some titles play flawless and some other files are skipped permanently. So I decided to investigate some time in this issue and create some test to identify which files are playing and which files not.

First of all I googled that issue and found some tips to convert the files to 192 kbps and 44.1 khz. This solution did the trick for some files but the most files still refused to playback so I took a deeper look into it.

For my first test, I took a file which doesn't playback in my car but works great on all other MP3 players and cellphones and converted it with lame (LAME 64bits version 3.99.5) with the following settings:


kbps/quality mode khz works
320 cbr 48 no
192 cbr 48 no
128 cbr 48 no
0 vbr 48 no
4 vbr 48 no
320 cbr 44.1 no
192 cbr 44.1 no
128 cbr 44.1 no
0 vbr 44.1 no
4 vbr 44.1 no

So what's wrong? Inspecting the file I noticed that in this file a cover image is embedded. Maybe such content causes the player to skip the file? Next, I used the command line tool eyeD3 (http://eyed3.nicfit.net/) to remove the embedded content from this file but keep the ID3-Tag. Now it's getting really weird. The file plays now with different bitrates, but only sometimes :-) Most times the file is still skipped but some times it plays correctly. For my next test, I removed the ID3-Tag completely from the file and these are the results:

kbps/quality mode khz works
320 cbr 48 no
192 cbr 48 no
128 cbr 48 no
0 vbr 48 no
4 vbr 48 no
320 cbr 44.1 yes
192 cbr 44.1 yes
128 cbr 44.1 yes
0 vbr 44.1 yes
4 vbr 44.1 yes


After a lot more toasted cd's I can present you my final results, playing MP3 files on a navigation business:

- The bitrate doesn't matter. Everything between 128 and 320 kbps works well
- Either a variable bitrate (vbr) or a constant bitrate (cbr) works
- khz must be 44.1
- Either CD's or DVD's can be used
- Remove all ID3 v1.x/v2.x tags. The player try's to skip this data, but mostly fails und than skips the whole file ($ eyeD3 --remove-all *.mp3).
- only 500 MP3's per disc are recognized. If there are more than 500 files on a disc, even if they are in subfolders, they won't be played

Please don't ask me how the tags can be removed on windows. I have no Windows but I think google can help you or someone can post a comment with a how-to :-)