Solved ... The raw pcm stream is 44.1 kHz 16bit stereo, which means 176400 bytes (44100*16*2/8) are one second. the raw stream bytes are counted after decode, before pushing them to the output. The playing is a thread already, so the main thread can change the volume at the right moment. mfg Andreas Zwinkau | web: andi.dasstellenwirinsinternet.de | mail: andi@buxach.de | jabber: beza1e1@amessage.de