Comment 49 for bug 996906

refer to src/core/Audio/AudioPulseAudio.cpp,

               buffer_attr.maxlength = (uint32_t)(-1);

   // play silence in case of buffer underun instead of using default rewind
   buffer_attr.prebuf = 0;

   buffer_attr.minreq = (uint32_t)(-1);
   buffer_attr.fragsize = (uint32_t)(-1);

   double latency = (double)( Engine::mixer()->framesPerPeriod() ) /
              (double)_this->sampleRate();

    // ask PulseAudio for the desired latency (which might not be approved)
    buffer_attr.tlength = pa_usec_to_bytes( latency * PA_USEC_PER_MSEC,
              &_this->m_sampleSpec );

   pa_stream_connect_playback( _this->m_s, NULL, &buffer_attr,
           PA_STREAM_ADJUST_LATENCY,
           NULL, // volume
           NULL );
    break;