If you are running ICS or greater and track info is not being displayed on your bluetooth device, be sure that Prefs -> General -> Lockscreen Player -> Disable ICS Lockscreen Controls is unchecked. The code that sends the track info over bluetooth also happens to be the same code that adds the lockscreen controls (this is nothing I have any control over)
Unfortunately my Bluetooth device (car radio) still doesn't display any track info, even if I leave the box unchecked. I'm running Android 4.1.2 on a Galaxy Note 2. It works with every other player I've tried (stock Samsung player, PowerAMP, PlayerPro...).
I can control GoneMAD player with the buttons in the car (play, skip, etc.) and sound is playing over the car stereo so A2DP and AVRCP works in general, but the track info is still missing. It's the only reason I still have PowerAmp installed. When I use my headphones I use GoneMAD because it just sounds better but in the car I use PowerAmp because it displays track info on my cars stereo (and sound quality doesn't matter much in the car). I would really like to stick with just GoneMAD though.
actually it appears the remotecontrolclient code might be broken as i cant even get the ICS lockscreen to show. Hopefully fixing that will fix the avrcp 1.3
edit. Make sure the disable ics controls is off.. then exit out of gmmp through the menu.. then launch it back up and try.. see if that fixes it. It seems that toggling that setting breaks things until its restarted. If that doestn work try restarting your phone
edit 2: it appears if you auto resume when plugging in headphones with the screen off.. it breaks it as well. So i have a few things to look at
I already have the settings as you suggested, (Disable ICS lock screen OFF, resume on headphone OFF), rebooted several times, installed new Roms (stock, omega, arhd). Nothing made any difference. I'll try subsonic and see if that player works, maybe that will help you to track the error down.
Report is sent. I won't have a chance to test subsonic until some time tomorrow. If I can assist you with testing in some other way please let me know. I'm a software engineer myself so I wouldn't have a problem with testing unstable debug builds on a daily basis if it helps you. I know how painful it is to debug an error that you can't reproduce.
Last Edit: Feb 1, 2013 18:16:38 GMT -5 by sseeland
Just a quick info: Subsonic shows the exact same symptoms as GMMP. Audio works, buttons work, track info doesn't. However I noticed the ticket on Sourceforge that you linked has the status open, so maybe the version from the Play store that I tested doesn't have the patch yet.