Updated MPlayer build is available at https://garage.maemo.org/projects/mplayer/

It contains improvements to gstreamer sound output support (-ao gst):
* added volume control
* fixed audio/video synchronization problems

Please test it and report any problems with -ao gst -ac dspmp3. If it works ok, the next build will have gstreamer sound output enabled by default (that's why -ao gst should be also tested with other decoders like -ad mad and non mp3 audio). By the way, the next build is likely to be packaged in .deb