public long getQueueBufferTimeUs() {
        return (long)((double)(mBufferQueue.mQueuedDataSize / mFrameSize)
                / mSampleRate * 1000000d);
    }
Returns the length of the queued audio, that does not fit into the playback buffer yet.
@return the length of the queued audio in microsecs
MediaPlayer/src/main/java/net/protyposis/android/mediaplayer/AudioPlayback.java