ESD_DEFAULT_RATE
bigtime_t serverLatency = result * 1000000LL / (ESD_DEFAULT_RATE * 2/*16b*/ * 2/*stereo*/ );
fDefaultRate = ESD_DEFAULT_RATE;
status_t SetFormat(int bits, int channels, float rate=ESD_DEFAULT_RATE);
fPreferredFormat.u.raw_audio.frame_rate = ESD_DEFAULT_RATE;