diff --git a/.gitignore b/.gitignore
index 93e4072..7893359 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ compiled/
 *.bak
 \#*
 .\#*
+libao/c/build
diff --git a/libao/c/ao-play-async/ao_playasync.c b/libao/c/ao-play-async/ao_playasync.c
index c7410c0..ec5ae59 100644
--- a/libao/c/ao-play-async/ao_playasync.c
+++ b/libao/c/ao-play-async/ao_playasync.c
@@ -1,20 +1,26 @@
 #include "ao_playasync.h"
-#include <ao/ao.h>
 #include <pthread.h>
 #include <unistd.h>
 #include <assert.h>
 #include <malloc.h>
 #include <string.h>
+#include <dlfcn.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
 
 typedef enum {
     PLAY = 1,
     STOP = 2
 } Command_t;
 
+typedef void * ao_device;
+
 typedef struct _queue_ {
     Command_t command;
     void *buf;
     int buflen;
+    double at_second;
     struct _queue_ *next;
     struct _queue_ *prev;
 } Queue_t;
@@ -25,8 +31,12 @@ typedef struct {
     ao_device   *ao_device;
     pthread_mutex_t mutex;
     pthread_t    thread;
+    double       at_second;
 } AO_Handle;
 
+static int(*ao_play)(void *device, char *samples, uint32_t n) = NULL;
+
+
 static Queue_t *front(AO_Handle *h)
 {
     assert(h->play_queue != NULL);
@@ -38,9 +48,10 @@ static Queue_t *get(AO_Handle *h)
     assert(h->play_queue != NULL);
     Queue_t *q = h->play_queue;
     h->play_queue = h->play_queue->next;
-    h->play_queue->prev = NULL;
     if (h->play_queue == NULL) {
         h->last_frame = NULL;
+    } else {
+        h->play_queue->prev = NULL;
     }
     return q;
 }
@@ -60,7 +71,7 @@ static void add(AO_Handle *h, Queue_t *elem)
     }
 }
 
-static Queue_t *new_elem(int command, int buf_len, void *buf)
+static Queue_t *new_elem(int command, double at_second, int buf_len, void *buf)
 {
     Queue_t *q = (Queue_t *) malloc(sizeof(Queue_t));
     void *new_buf;
@@ -71,6 +82,7 @@ static Queue_t *new_elem(int command, int buf_len, void *buf)
     } else {
         new_buf = NULL;
     }
+    q->at_second = at_second;
     q->buf = new_buf;
     q->buflen = buf_len;
     q->command = command;
@@ -79,14 +91,19 @@ static Queue_t *new_elem(int command, int buf_len, void *buf)
     return q;
 }
 
+static void del_elem(Queue_t *q)
+{
+    if (q->buflen != 0) {
+        free(q->buf);
+    }
+    free(q);
+}
+
 static void clear(AO_Handle *h)
 {
     while (h->play_queue != NULL) {
         Queue_t *q = get(h);
-        if (q->buflen != 0) {
-            free(q->buf);
-        }
-        free(q);
+        del_elem(q);
     }
 }
 
@@ -101,9 +118,17 @@ static void *run(void *arg)
         int has_frames = (handle->play_queue != NULL);
 
         if (has_frames) {
-
+            Queue_t *q = get(handle);
+            handle->at_second = q->at_second;
             pthread_mutex_unlock(&handle->mutex);
 
+            if (q->command == STOP) {
+                go_on = (1 == 0);
+            } else {
+                ao_play(handle->ao_device, q->buf, q->buflen);
+            }
+
+            del_elem(q);
         } else {
             pthread_mutex_unlock(&handle->mutex);
             usleep(5000);   // sleep for 5ms
@@ -113,13 +138,35 @@ static void *run(void *arg)
     return NULL;
 }
 
+static void get_ao_play(void)
+{
+    char *lib = "libao.so";
+    void *handle = dlopen(lib, RTLD_LAZY);
+    if (!handle) {
+        fprintf(stderr, "Cannot open library %s: %s\n", lib, dlerror());
+        exit(EXIT_FAILURE);
+    }
+
+    ao_play = dlsym(handle, "ao_play");
+    char *err;
+    err = dlerror();
+    if (err != NULL) {
+        fprintf(stderr, "Cannot get function ao_play: %s\n", err);
+        exit(EXIT_FAILURE);
+    }
+}
+
+
 void *ao_create_async(void *ao_device_yeah)
 {
+    if (ao_play == NULL) { get_ao_play(); }
+
     AO_Handle *handle = (AO_Handle *) malloc(sizeof(AO_Handle));
 
     handle->ao_device = (ao_device *) ao_device_yeah;
     handle->play_queue = NULL;
     handle->last_frame = NULL;
+    handle->at_second = -1;
     pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
     handle->mutex = m;
 
@@ -131,16 +178,32 @@ void *ao_create_async(void *ao_device_yeah)
 void ao_stop_async(void *ao_handle)
 {
     AO_Handle *h = (AO_Handle *) ao_handle;
+
+    pthread_mutex_lock(&h->mutex);
     clear(h);
-    Queue_t *q = new_elem(STOP, 0, NULL);
+    Queue_t *q = new_elem(STOP, 0.0, 0, NULL);
     add(h, q);
+    pthread_mutex_unlock(&h->mutex);
+
+    void *retval;
+    pthread_join(h->thread, &retval);
+    free(h);
 }
 
-void ao_play_async(void *ao_handle, int buf_size, void *mem)
+void ao_play_async(void *ao_handle, double at_second, int buf_size, void *mem)
 {
     AO_Handle *h = (AO_Handle *) ao_handle;
-    Queue_t *q = new_elem(PLAY, buf_size, mem);
+    Queue_t *q = new_elem(PLAY, at_second, buf_size, mem);
+    pthread_mutex_lock(&h->mutex);
     add(h, q);
+    pthread_mutex_unlock(&h->mutex);
+}
+
+double ao_is_at_second_async(void *ao_handle)
+{
+    AO_Handle *h = (AO_Handle *) ao_handle;
+    return h->at_second;
 }
 
 
+
diff --git a/libao/c/ao-play-async/ao_playasync.h b/libao/c/ao-play-async/ao_playasync.h
index 4bf3c36..4aeb12e 100644
--- a/libao/c/ao-play-async/ao_playasync.h
+++ b/libao/c/ao-play-async/ao_playasync.h
@@ -3,6 +3,7 @@
 
 extern void *ao_create_async(void *ao_handle);
 extern void ao_stop_async(void *handle);
-extern void ao_play_async(void *handle, int buf_size, void *mem);
+extern void ao_play_async(void *handle, double at_second, int buf_size, void *mem);
+extern double ao_is_at_second_async(void *handle);
 
 #endif // AO_PLAYASYNC_H
diff --git a/libao/libao-async-ffi.rkt b/libao/libao-async-ffi.rkt
new file mode 100644
index 0000000..91e0003
--- /dev/null
+++ b/libao/libao-async-ffi.rkt
@@ -0,0 +1,37 @@
+#lang racket/base
+
+
+(require ffi/unsafe
+         ffi/unsafe/define
+         setup/dirs
+         "../utils/utils.rkt"
+         )
+
+(provide ao_create_async
+         ao_stop_async
+         ao_play_async
+         ao_is_at_second_async
+         )
+
+;(ffi-lib "/usr/local/lib/libao-play-async.so")
+
+(define-ffi-definer define-libao-async
+  (ffi-lib "libao-play-async" '("0" #f)
+           #:get-lib-dirs (lambda ()
+                            (cons (build-path ".") (get-lib-search-dirs)))
+           #:fail (λ () (error "Cannot load libao-play-async"))
+           ))
+
+(define _libao-async-handle-pointer (_cpointer 'ao-async-handle))
+
+;extern void *ao_create_async(void *ao_device);
+(define-libao-async ao_create_async(_fun _pointer -> _libao-async-handle-pointer))
+
+;extern void ao_stop_async(void *handle);
+(define-libao-async ao_stop_async(_fun _libao-async-handle-pointer -> _void))
+
+;extern void ao_play_async(void *handle, double at_second, int buf_size, void *mem);
+(define-libao-async ao_play_async(_fun _libao-async-handle-pointer _double _uint32 _pointer -> _void))
+
+;extern double ao_is_at_second_async(void *handle);
+(define-libao-async ao_is_at_second_async(_fun _libao-async-handle-pointer -> _double))
diff --git a/libao/libao.rkt b/libao/libao.rkt
index 798a59f..017d713 100644
--- a/libao/libao.rkt
+++ b/libao/libao.rkt
@@ -1,6 +1,7 @@
 #lang racket/base
 
 (require "libao-ffi.rkt"
+         "libao-async-ffi.rkt"
          (prefix-in fin: finalizer)
          ffi/unsafe
          data/queue
@@ -11,6 +12,7 @@
          ao-mk-format
          ao-close
          ao-default-driver-id
+         ao-at-second
          )
 
 (define devices (make-hash))
@@ -23,8 +25,7 @@
                           [byte-format #:auto #:mutable]
                           [channels #:auto #:mutable]
                           [rate #:auto #:mutable]
-                          [buffer #:auto #:mutable]
-                          [player #:auto #:mutable]
+                          [async-player #:auto #:mutable]
                           )
   #:auto-value #f
   )
@@ -84,36 +85,7 @@
                 (set-ao-handle-byte-format! handle endianness)
                 (set-ao-handle-rate! handle rate)
                 (set-ao-handle-channels! handle channels)
-                (let ((buf (make-queue)))
-                  (set-ao-handle-buffer! handle buf)
-                  (set-ao-handle-player! handle
-                                         (thread (λ ()
-                                                   (let ((samples-per-time 10)
-                                                         (sample 0)
-                                                         )
-                                                     (define (play)
-                                                       (displayln (format "Queue-length: ~a" (queue-length buf)))
-                                                       (if (queue-empty? buf)
-                                                           (begin
-                                                             (sleep 0.1)
-                                                             (play))
-                                                         (let ((front (dequeue! buf)))
-                                                           (if (eq? (car front) 'close)
-                                                               'closed
-                                                               (let ((audio (cadr front))
-                                                                     (audio-buf-len (caddr front)))
-                                                                 (ao_play ao-device audio audio-buf-len)
-                                                                 (play))
-                                                               )
-                                                           )
-                                                         )
-                                                     )
-                                                     (play))
-                                                   )
-                                                 #:pool 'own
-                                                 )
-                                         )
-                  )
+                (set-ao-handle-async-player! handle (ao_create_async ao-device))
                 (hash-set! devices handle-num ao-device)
                 (fin:register-finalizer handle
                                         (lambda (handle)
@@ -131,15 +103,7 @@
               (printf "Unexpected: cannot close ao-device"))))
         'internally-closed)
       (let ((handle-num (ao-handle-handle-num handle)))
-        (let ((q (ao-handle-buffer handle)))
-          (letrec ((emptier (λ () (if (queue-empty? q)
-                                      'done
-                                      (begin
-                                        (dequeue! q)
-                                        (emptier))))))
-            (emptier)
-            (enqueue! q (list 'close #f #f))
-            ))
+        (ao_stop_async (ao-handle-async-player handle))
         (let ((ao-device (hash-ref devices handle-num #f)))
           (if (eq? ao-device #f)
               'error-ao-device-non-existent
@@ -164,7 +128,7 @@
           (reverse bytes)
           bytes))))
 
-(define (ao-play handle buffer)
+(define (ao-play handle at-time-in-s buffer)
   (let* ((bytes-per-sample (ao-handle-bytes-per-sample handle))
          (bits (ao-handle-bits handle))
          (channels (ao-handle-channels handle))
@@ -195,11 +159,14 @@
                          'filled))
                    ))
       (fill 0 0)
-      (enqueue! (ao-handle-buffer handle) (list 'play-buf audio audio-buf-len))
+      (ao_play_async (ao-handle-async-player handle) (exact->inexact at-time-in-s) audio-buf-len audio)
       )
     )
   )
 
+(define (ao-at-second handle)
+  (ao_is_at_second_async (ao-handle-async-player handle)))
+
 ;(let* ((handle-num (ao-handle-handle-num handle))
 ;             (ao-device (hash-ref devices handle-num #f)))
 ;        (if (eq? ao-device #f)
diff --git a/play-test.rkt b/play-test.rkt
index f8a9f1c..65bda67 100644
--- a/play-test.rkt
+++ b/play-test.rkt
@@ -10,8 +10,21 @@
 (define fmt (ao-mk-format 24 48000 2 'big-endian))
 (define ao-h (ao-open-live #f fmt))
 
+(define current-seconds 0)
+
 (define (flac-play frame buffer)
-  (ao-play ao-h buffer))
+  (let* ((sample (hash-ref frame 'number))
+         (rate (hash-ref frame 'sample-rate))
+         (second (/ (* sample 1.0) (* rate 1.0)))
+         )
+    (ao-play ao-h second buffer)
+    )
+  (let ((s (inexact->exact (round (ao-at-second ao-h)))))
+    (when (> s current-seconds)
+      (set! current-seconds s)
+      (displayln (format "At second: ~a" (ao-at-second ao-h)))
+      ))
+  )
 
 (define (flac-meta meta)
   (displayln meta))