I've been working mostly for the last 2 weeks on improving the audioengine performance. HTC devices in particular would stutter like crazy when the screen was off (even top of the line htc devices like the one x). The tweaks i made seem to fix most of those stuttering issues. I also discovered how to let gmmp work with external dsps like dspmanager, which was a request I got from numerous users.
I mentioned it in the changelog but your buffer settings and priorities have been reset due to the audioengine tweaks made. I wanted everyone back on the defaults to start.
1.4.7 (03/04/2013):
-Fixed crash related to invalid min audio buffer size
-The next track in now playing will now properly update after reordering the queue
-Fixed notification related crash
-Fixed some instances where the seekbar would jump back to the beginning temporarily when playing
-Improved seekbar accuracy with the equalizer enabled
-Improved seek response time
-Slightly reduced default memory usage
-Tweaked the audioengine for improved performance and less stuttering when screen is off (problem with many HTC devices)
-Reset buffer size, dsp priority, and decoder priority in the settings due to the tweaks mentioned above
-Audiofocus is now regained after resuming playback
-External dsps like DspManager should now work with GMMP