Just wanted to share this here. There is clear audible decrease in audio quality on 4.2.2 when listening over bluetooth (A2DP). All the higher tones were somehow garbled, like cymbals, or high vocals, etc. I could clearly notice the poor quality on 4.2.2 on my car stereo and also the improvement after installing the fix on my stock rooted GN 4.2.2 (GSM). I haven't tested this on custom ROMs.
- Root your phone, if not rooted
- Make Nandroid backup (in worst case, you might not be able to boot)
- Download bluetooth.default.so http://code.google.com/p/android/issues/detail?id=39632#c158 Also attached to this message.
- Download audio.a2dp.default.so http://code.google.com/p/android/issues/detail?id=39632#c163 Also attached to this message.
- In /system/lib/hw, rename bluetooth.default.so to bluetooth.default.so.bak (or whatever)
- In /system/lib/hw, rename audio.a2dp.default.so to audio.a2dp.default.so.bak (or whatever)
- Copy files to /system/lib/hw
- Set permission on both files to be same as with the original files (644)
- Restart phone