apexsink: Add support for generation 2 AirTunes hardware

Fixes bug #649931.

4 files changed, 268 insertions, 38 deletions

diff --git a/ext/apexsink/gstapexraop.c b/ext/apexsink/gstapexraop.c
index 4d07674b0..04c49a2b3 100644
--- a/ext/apexsink/gstapexraop.c
+++ b/ext/apexsink/gstapexraop.c
@@ -52,14 +52,15 @@ const static gchar GST_APEX_RAOP_RSA_PUBLIC_EXP[] = "AQAB";
 const static gchar GST_APEX_RAOP_USER_AGENT[] =
     "iTunes/4.6 (Macintosh; U; PPC Mac OS X 10.3)";
 
-const static guchar GST_APEX_RAOP_FRAME_HEADER[] = {
+const static guchar GST_APEX_RAOP_FRAME_HEADER[] = {    // Used by gen. 1
   0x24, 0x00, 0x00, 0x00,
   0xF0, 0xFF, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00,
   0x00, 0x00, 0x00, 0x00
 };
 
-const static int GST_APEX_RAOP_FRAME_HEADER_SIZE = 16;
+const static int GST_APEX_RAOP_FRAME_HEADER_SIZE = 16;  // Used by gen. 1
+const static int GST_APEX_RTP_FRAME_HEADER_SIZE = 12;   // Used by gen. 2
 
 const static int GST_APEX_RAOP_ALAC_HEADER_SIZE = 3;
 
@@ -121,6 +122,9 @@ typedef struct
   GstApExJackType jack_type;    /* APEX connected jack type, once ANNOUNCE performed */
   GstApExJackStatus jack_status;        /* APEX connected jack status, once ANNOUNCE performed */
 
+  GstApExGeneration generation; /* Different devices accept different audio streams */
+  GstApExTransportProtocol transport_protocol;  /* For media stream, not RAOP/RTSP */
+
   gchar *host;                  /* APEX target ip */
   guint ctrl_port;              /* APEX target control port */
   guint data_port;              /* APEX negotiated data port, once SETUP performed */
@@ -130,12 +134,18 @@ typedef struct
 
   int data_sd;                  /* data socket */
   struct sockaddr_in data_sd_in;
+
+  short rtp_seq_num;            /* RTP sequence number, used by gen. 2 */
+  int rtp_timestamp;            /* RTP timestamp,       used by gen. 2 */
 }
 _GstApExRAOP;
 
 /* raop apex struct allocation */
 GstApExRAOP *
-gst_apexraop_new (const gchar * host, const guint16 port)
+gst_apexraop_new (const gchar * host,
+    const guint16 port,
+    const GstApExGeneration generation,
+    const GstApExTransportProtocol transport_protocol)
 {
   _GstApExRAOP *apexraop;
 
@@ -146,6 +156,10 @@ gst_apexraop_new (const gchar * host, const guint16 port)
   apexraop->ua = g_strdup (GST_APEX_RAOP_USER_AGENT);
   apexraop->jack_type = GST_APEX_JACK_TYPE_UNDEFINED;
   apexraop->jack_status = GST_APEX_JACK_STATUS_DISCONNECTED;
+  apexraop->generation = generation;
+  apexraop->transport_protocol = transport_protocol;
+  apexraop->rtp_seq_num = 0;
+  apexraop->rtp_timestamp = 0;
 
   return (GstApExRAOP *) apexraop;
 }
@@ -311,7 +325,9 @@ gst_apexraop_connect (GstApExRAOP * con)
       conn->url_abspath,
       inaddr,
       conn->host,
-      GST_APEX_RAOP_SAMPLES_PER_FRAME,
+      conn->generation == GST_APEX_GENERATION_ONE
+      ? GST_APEX_RAOP_V1_SAMPLES_PER_FRAME
+      : GST_APEX_RAOP_V2_SAMPLES_PER_FRAME,
       GST_APEX_RAOP_BYTES_PER_CHANNEL * 8,
       GST_APEX_RAOP_CHANNELS, GST_APEX_RAOP_BITRATE, ky, iv);
 
@@ -451,8 +467,14 @@ gst_apexraop_connect (GstApExRAOP * con)
   if (res != GST_RTSP_STS_OK)
     return res;
 
-  if ((conn->data_sd = socket (AF_INET, SOCK_STREAM, 0)) < 0)
-    return GST_RTSP_STS_DESTINATION_UNREACHABLE;
+  if (conn->transport_protocol == GST_APEX_TCP) {
+    if ((conn->data_sd = socket (AF_INET, SOCK_STREAM, 0)) < 0)
+      return GST_RTSP_STS_DESTINATION_UNREACHABLE;
+  } else if (conn->transport_protocol == GST_APEX_UDP) {
+    if ((conn->data_sd = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
+      return GST_RTSP_STS_DESTINATION_UNREACHABLE;
+  } else
+    return GST_RTSP_STS_METHOD_NOT_ALLOWED;
 
   conn->data_sd_in.sin_family = AF_INET;
   conn->data_sd_in.sin_port = htons (conn->data_port);
@@ -495,6 +517,34 @@ gst_apexraop_get_jackstatus (GstApExRAOP * con)
   return conn->jack_status;
 }
 
+/* raop apex generation access */
+GstApExGeneration
+gst_apexraop_get_generation (GstApExRAOP * con)
+{
+  _GstApExRAOP *conn;
+
+  conn = (_GstApExRAOP *) con;
+
+  if (!conn)
+    return GST_APEX_GENERATION_ONE;
+
+  return conn->generation;
+}
+
+/* raop apex transport protocol access */
+GstApExTransportProtocol
+gst_apexraop_get_transport_protocol (GstApExRAOP * con)
+{
+  _GstApExRAOP *conn;
+
+  conn = (_GstApExRAOP *) con;
+
+  if (!conn)
+    return GST_APEX_TCP;
+
+  return conn->transport_protocol;
+}
+
 /* raop apex sockets close */
 void
 gst_apexraop_close (GstApExRAOP * con)
@@ -628,25 +678,49 @@ gst_apexraop_write (GstApExRAOP * con, gpointer rawdata, guint length)
   gushort len;
   gint bit_offset, byte_offset, i, out_len, res;
   EVP_CIPHER_CTX aes_ctx;
-  _GstApExRAOP *conn;
-
-  conn = (_GstApExRAOP *) con;
+  _GstApExRAOP *conn = (_GstApExRAOP *) con;
+  const int frame_header_size = conn->generation == GST_APEX_GENERATION_ONE
+      ? GST_APEX_RAOP_FRAME_HEADER_SIZE : GST_APEX_RTP_FRAME_HEADER_SIZE;
 
   buffer =
-      (guchar *) g_malloc0 (GST_APEX_RAOP_FRAME_HEADER_SIZE +
+      (guchar *) g_malloc0 (frame_header_size +
       GST_APEX_RAOP_ALAC_HEADER_SIZE + length);
 
-  memcpy (buffer, GST_APEX_RAOP_FRAME_HEADER, GST_APEX_RAOP_FRAME_HEADER_SIZE);
+  if (conn->generation == GST_APEX_GENERATION_ONE) {
+    g_assert (frame_header_size == GST_APEX_RAOP_FRAME_HEADER_SIZE);
+    memcpy (buffer, GST_APEX_RAOP_FRAME_HEADER, frame_header_size);
 
-  len =
-      length + GST_APEX_RAOP_FRAME_HEADER_SIZE +
-      GST_APEX_RAOP_ALAC_HEADER_SIZE - 4;
-  buffer[2] = len >> 8;
-  buffer[3] = len & 0xff;
+    len = length + frame_header_size + GST_APEX_RAOP_ALAC_HEADER_SIZE - 4;
+
+    buffer[2] = len >> 8;
+    buffer[3] = len & 0xff;
+  } else {
+    /* Gen. 2 uses RTP-like header (RFC 3550). */
+    short network_seq_num;
+    int network_timestamp, unknown_const;
+    static gboolean first = TRUE;
+
+    buffer[0] = 0x80;
+    if (first) {
+      buffer[1] = 0xe0;
+      first = FALSE;
+    } else
+      buffer[1] = 0x60;
+
+    network_seq_num = htons (conn->rtp_seq_num++);
+    memcpy (buffer + 2, &network_seq_num, 2);
+
+    network_timestamp = htons (conn->rtp_timestamp);
+    memcpy (buffer + 4, &network_timestamp, 4);
+    conn->rtp_timestamp += GST_APEX_RAOP_V2_SAMPLES_PER_FRAME;
+
+    unknown_const = 0xdeadbeef;
+    memcpy (buffer + 8, &unknown_const, 4);
+  }
 
   bit_offset = 0;
   byte_offset = 0;
-  frame_data = buffer + GST_APEX_RAOP_FRAME_HEADER_SIZE;
+  frame_data = buffer + frame_header_size;
 
   gst_apexraop_write_bits (frame_data, 1, 3, &bit_offset, &byte_offset);        /* channels, 0 mono, 1 stereo */
   gst_apexraop_write_bits (frame_data, 0, 4, &bit_offset, &byte_offset);        /* unknown */
@@ -673,16 +747,14 @@ gst_apexraop_write (GstApExRAOP * con, gpointer rawdata, guint length)
 
   res =
       gst_apexraop_send (conn->data_sd, buffer,
-      GST_APEX_RAOP_FRAME_HEADER_SIZE + GST_APEX_RAOP_ALAC_HEADER_SIZE +
-      length);
+      frame_header_size + GST_APEX_RAOP_ALAC_HEADER_SIZE + length);
 
   g_free (buffer);
 
   return (guint) ((res >=
-          (GST_APEX_RAOP_FRAME_HEADER_SIZE +
+          (frame_header_size +
               GST_APEX_RAOP_ALAC_HEADER_SIZE)) ? (res -
-          GST_APEX_RAOP_FRAME_HEADER_SIZE -
-          GST_APEX_RAOP_ALAC_HEADER_SIZE) : 0);
+          frame_header_size - GST_APEX_RAOP_ALAC_HEADER_SIZE) : 0);
 }
 
 /* raop apex buffer flush */
@@ -701,10 +773,13 @@ gst_apexraop_flush (GstApExRAOP * con)
       "Client-Instance: %s\r\n"
       "User-Agent: %s\r\n"
       "Session: %s\r\n"
-      "RTP-Info: seq=0;rtptime=0\r\n"
+      "RTP-Info: seq=%d;rtptime=%d\r\n"
       "\r\n",
       conn->host,
-      conn->url_abspath, ++conn->cseq, conn->cid, conn->ua, conn->session);
+      conn->url_abspath,
+      ++conn->cseq,
+      conn->cid,
+      conn->ua, conn->session, conn->rtp_seq_num, conn->rtp_timestamp);
 
   if (gst_apexraop_send (conn->ctrl_sd, hreq, strlen (hreq)) <= 0)
     return GST_RTSP_STS_GONE;
diff --git a/ext/apexsink/gstapexraop.h b/ext/apexsink/gstapexraop.h
index fe1ba41b7..462118e23 100644
--- a/ext/apexsink/gstapexraop.h
+++ b/ext/apexsink/gstapexraop.h
@@ -48,7 +48,8 @@ G_BEGIN_DECLS
 
 /* raop fixed parameters */
 #define GST_APEX_RAOP_BITRATE				44100
-#define GST_APEX_RAOP_SAMPLES_PER_FRAME			4096
+#define GST_APEX_RAOP_V1_SAMPLES_PER_FRAME		4096
+#define GST_APEX_RAOP_V2_SAMPLES_PER_FRAME		352
 #define GST_APEX_RAOP_BYTES_PER_CHANNEL			2
 #define GST_APEX_RAOP_CHANNELS				2
 #define GST_APEX_RAOP_BYTES_PER_SAMPLE			(GST_APEX_RAOP_CHANNELS * GST_APEX_RAOP_BYTES_PER_CHANNEL)
@@ -78,13 +79,30 @@ typedef enum
 }
 GstApExJackStatus;
 
+typedef enum
+{
+  GST_APEX_GENERATION_ONE = 1,
+  GST_APEX_GENERATION_TWO,
+}
+GstApExGeneration;
+
+typedef enum
+{
+  GST_APEX_TCP = 0,
+  GST_APEX_UDP,
+}
+GstApExTransportProtocol;
+
 /* raop context handle */
 typedef struct
 {
 } GstApExRAOP;
 
 /* host might be null and port might be 0 while instanciating */
-GstApExRAOP *gst_apexraop_new (const gchar * host, const guint16 port);
+GstApExRAOP *gst_apexraop_new (const gchar * host,
+                               const guint16 port,
+			       const GstApExGeneration generation,
+			       const GstApExTransportProtocol transport_protocol);
 void gst_apexraop_free (GstApExRAOP * conn);
 
 /* must not be connected yet while setting the host target */
@@ -118,6 +136,12 @@ GstRTSPStatusCode gst_apexraop_flush (GstApExRAOP * conn);
 GstApExJackType gst_apexraop_get_jacktype (GstApExRAOP * conn);
 GstApExJackStatus gst_apexraop_get_jackstatus (GstApExRAOP * conn);
 
+/* retrieve the generation */
+GstApExGeneration gst_apexraop_get_generation (GstApExRAOP * conn);
+
+/* retrieve the transport protocol */
+GstApExTransportProtocol gst_apexraop_get_transport_protocol (GstApExRAOP * conn);
+
 G_END_DECLS
 
 #endif
diff --git a/ext/apexsink/gstapexsink.c b/ext/apexsink/gstapexsink.c
index 8daaa23fc..fc64db83a 100644
--- a/ext/apexsink/gstapexsink.c
+++ b/ext/apexsink/gstapexsink.c
@@ -59,6 +59,8 @@ enum
   APEX_PROP_VOLUME,
   APEX_PROP_JACK_TYPE,
   APEX_PROP_JACK_STATUS,
+  APEX_PROP_GENERATION,
+  APEX_PROP_TRANSPORT_PROTOCOL,
 };
 
 #define DEFAULT_APEX_HOST		""
@@ -66,6 +68,8 @@ enum
 #define DEFAULT_APEX_VOLUME		1.0
 #define DEFAULT_APEX_JACK_TYPE		GST_APEX_JACK_TYPE_UNDEFINED
 #define DEFAULT_APEX_JACK_STATUS	GST_APEX_JACK_STATUS_UNDEFINED
+#define DEFAULT_APEX_GENERATION		GST_APEX_GENERATION_ONE
+#define DEFAULT_APEX_TRANSPORT_PROTOCOL	GST_APEX_TCP
 
 /* genum apex jack resolution */
 GType
@@ -108,6 +112,43 @@ gst_apexsink_jacktype_get_type (void)
   return jacktype_type;
 }
 
+GType
+gst_apexsink_generation_get_type (void)
+{
+  static GType generation_type = 0;
+  static GEnumValue generation[] = {
+    {GST_APEX_GENERATION_ONE, "generation-one",
+        "First generation (e.g., original AirPort Express)"},
+    {GST_APEX_GENERATION_TWO, "generation-two",
+        "Second generation (e.g., Apple TV v2)"},
+    {0, NULL, NULL},
+  };
+
+  if (!generation_type) {
+    generation_type = g_enum_register_static ("GstApExGeneration", generation);
+  }
+
+  return generation_type;
+}
+
+GType
+gst_apexsink_transport_protocol_get_type (void)
+{
+  static GType transport_protocol_type = 0;
+  static GEnumValue transport_protocol[] = {
+    {GST_APEX_TCP, "tcp", "TCP"},
+    {GST_APEX_UDP, "udp", "UDP"},
+    {0, NULL, NULL},
+  };
+
+  if (!transport_protocol_type) {
+    transport_protocol_type =
+        g_enum_register_static ("GstApExTransportProtocol", transport_protocol);
+  }
+
+  return transport_protocol_type;
+}
+
 
 static void gst_apexsink_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec);
@@ -124,6 +165,8 @@ static gboolean gst_apexsink_unprepare (GstAudioSink * asink);
 static guint gst_apexsink_delay (GstAudioSink * asink);
 static void gst_apexsink_reset (GstAudioSink * asink);
 static gboolean gst_apexsink_close (GstAudioSink * asink);
+static GstStateChangeReturn gst_apexsink_change_state (GstElement * element,
+    GstStateChange transition);
 
 /* mixer interface standard api */
 static void gst_apexsink_interfaces_init (GType type);
@@ -252,6 +295,9 @@ gst_apexsink_class_init (GstApExSinkClass * klass)
   ((GstAudioSinkClass *) klass)->reset = GST_DEBUG_FUNCPTR (gst_apexsink_reset);
   ((GstAudioSinkClass *) klass)->close = GST_DEBUG_FUNCPTR (gst_apexsink_close);
 
+  ((GstElementClass *) klass)->change_state =
+      GST_DEBUG_FUNCPTR (gst_apexsink_change_state);
+
   g_object_class_install_property ((GObjectClass *) klass, APEX_PROP_HOST,
       g_param_spec_string ("host", "Host", "AirPort Express target host",
           DEFAULT_APEX_HOST, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
@@ -275,6 +321,17 @@ gst_apexsink_class_init (GstApExSinkClass * klass)
           "AirPort Express jack connection status",
           GST_APEX_SINK_JACKSTATUS_TYPE, DEFAULT_APEX_JACK_STATUS,
           G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property ((GObjectClass *) klass,
+      APEX_PROP_GENERATION, g_param_spec_enum ("generation", "Generation",
+          "AirPort device generation",
+          GST_APEX_SINK_GENERATION_TYPE, DEFAULT_APEX_GENERATION,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  g_object_class_install_property ((GObjectClass *) klass,
+      APEX_PROP_TRANSPORT_PROTOCOL, g_param_spec_enum ("transport-protocol",
+          "Transport Protocol", "AirPort transport protocol",
+          GST_APEX_SINK_TRANSPORT_PROTOCOL_TYPE,
+          DEFAULT_APEX_TRANSPORT_PROTOCOL,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 }
 
 /* sink plugin instance init */
@@ -295,6 +352,8 @@ gst_apexsink_init (GstApExSink * apexsink, GstApExSinkClass * g_class)
   apexsink->volume = CLAMP (DEFAULT_APEX_VOLUME * 75, 0, 100);
   apexsink->gst_apexraop = NULL;
   apexsink->tracks = g_list_append (apexsink->tracks, track);
+  apexsink->clock = gst_system_clock_obtain ();
+  apexsink->clock_id = NULL;
 
   GST_INFO_OBJECT (apexsink,
       "ApEx sink default initialization, target=\"%s\", port=\"%d\", volume=\"%d%%\"",
@@ -343,6 +402,28 @@ gst_apexsink_set_property (GObject * object, guint prop_id,
       GST_INFO_OBJECT (sink, "ApEx volume set to \"%d%%\"", sink->volume);
       break;
     }
+    case APEX_PROP_GENERATION:
+      if (sink->gst_apexraop == NULL) {
+        sink->generation = g_value_get_enum (value);
+
+        GST_INFO_OBJECT (sink, "ApEx generation set to \"%d\"",
+            sink->generation);
+      } else {
+        GST_WARNING_OBJECT (sink,
+            "SET-PROPERTY : generation property may not be set when apexsink opened !");
+      }
+      break;
+    case APEX_PROP_TRANSPORT_PROTOCOL:
+      if (sink->gst_apexraop == NULL) {
+        sink->transport_protocol = g_value_get_enum (value);
+
+        GST_INFO_OBJECT (sink, "ApEx transport protocol set to \"%d\"",
+            sink->transport_protocol);
+      } else {
+        GST_WARNING_OBJECT (sink,
+            "SET-PROPERTY : transport protocol property may not be set when apexsink opened !");
+      }
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -373,6 +454,14 @@ gst_apexsink_get_property (GObject * object, guint prop_id, GValue * value,
       g_value_set_enum (value,
           gst_apexraop_get_jackstatus (sink->gst_apexraop));
       break;
+    case APEX_PROP_GENERATION:
+      g_value_set_enum (value,
+          gst_apexraop_get_generation (sink->gst_apexraop));
+      break;
+    case APEX_PROP_TRANSPORT_PROTOCOL:
+      g_value_set_enum (value,
+          gst_apexraop_get_transport_protocol (sink->gst_apexraop));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -391,6 +480,8 @@ gst_apexsink_finalise (GObject * object)
     sink->tracks = NULL;
   }
 
+  gst_object_unref (sink->clock);
+
   g_free (sink->host);
 
   G_OBJECT_CLASS (parent_class)->finalize (object);
@@ -403,7 +494,8 @@ gst_apexsink_open (GstAudioSink * asink)
   int res;
   GstApExSink *apexsink = (GstApExSink *) asink;
 
-  apexsink->gst_apexraop = gst_apexraop_new (apexsink->host, apexsink->port);
+  apexsink->gst_apexraop = gst_apexraop_new (apexsink->host,
+      apexsink->port, apexsink->generation, apexsink->transport_protocol);
 
   if ((res = gst_apexraop_connect (apexsink->gst_apexraop)) != GST_RTSP_STS_OK) {
     GST_ERROR_OBJECT (apexsink,
@@ -460,12 +552,14 @@ static gboolean
 gst_apexsink_prepare (GstAudioSink * asink, GstRingBufferSpec * spec)
 {
   GstApExSink *apexsink = (GstApExSink *) asink;
+  GstApExGeneration gen = gst_apexraop_get_generation (apexsink->gst_apexraop);
 
   apexsink->latency_time = spec->latency_time;
 
-  spec->segsize =
-      GST_APEX_RAOP_SAMPLES_PER_FRAME * GST_APEX_RAOP_BYTES_PER_SAMPLE;
-  spec->segtotal = 1;
+  spec->segsize = gen == GST_APEX_GENERATION_ONE
+      ? GST_APEX_RAOP_V1_SAMPLES_PER_FRAME * GST_APEX_RAOP_BYTES_PER_SAMPLE
+      : GST_APEX_RAOP_V2_SAMPLES_PER_FRAME * GST_APEX_RAOP_BYTES_PER_SAMPLE;
+  spec->segtotal = 2;
 
   memset (spec->silence_sample, 0, sizeof (spec->silence_sample));
 
@@ -481,17 +575,28 @@ gst_apexsink_prepare (GstAudioSink * asink, GstRingBufferSpec * spec)
 static guint
 gst_apexsink_write (GstAudioSink * asink, gpointer data, guint length)
 {
+  guint written;
   GstApExSink *apexsink = (GstApExSink *) asink;
 
-  if (gst_apexraop_write (apexsink->gst_apexraop, data, length) != length) {
+  if ((written =
+          gst_apexraop_write (apexsink->gst_apexraop, data,
+              length)) != length) {
     GST_INFO_OBJECT (apexsink,
-        "WRITE : %d bytes not fully sended, skipping frame samples...", length);
+        "WRITE : %d of %d bytes sent, skipping frame samples...", written,
+        length);
   } else {
     GST_INFO_OBJECT (apexsink, "WRITE : %d bytes sent", length);
-
-    /* FIXME, sleeping is ugly and not interruptible */
-    usleep ((gulong) ((length * 1000000.) / (GST_APEX_RAOP_BITRATE *
-                GST_APEX_RAOP_BYTES_PER_SAMPLE) - apexsink->latency_time));
+    /* NOTE, previous calculation subtracted apexsink->latency_time from this;
+     * however, the value below is less than apexsink->latency_time for generation 2.
+     * In this case, the number went negative (actualy wrapped around into a big number).
+     */
+    apexsink->clock_id = gst_clock_new_single_shot_id (apexsink->clock,
+        (GstClockTime) (gst_clock_get_time (apexsink->clock) +
+            ((length * 1000000000.)
+                / (GST_APEX_RAOP_BITRATE * GST_APEX_RAOP_BYTES_PER_SAMPLE))));
+    gst_clock_id_wait (apexsink->clock_id, NULL);
+    gst_clock_id_unref (apexsink->clock_id);
+    apexsink->clock_id = NULL;
   }
 
   return length;
@@ -545,3 +650,16 @@ gst_apexsink_close (GstAudioSink * asink)
 
   return TRUE;
 }
+
+static GstStateChangeReturn
+gst_apexsink_change_state (GstElement * element, GstStateChange transition)
+{
+  GstApExSink *apexsink = (GstApExSink *) element;
+
+  if (apexsink->clock_id && transition == GST_STATE_CHANGE_PAUSED_TO_READY) {
+    gst_clock_id_unschedule (apexsink->clock_id);
+    gst_clock_id_unref (apexsink->clock_id);
+    apexsink->clock_id = NULL;
+  }
+  return GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+}
diff --git a/ext/apexsink/gstapexsink.h b/ext/apexsink/gstapexsink.h
index 11d2f1ef9..ad2b299e3 100644
--- a/ext/apexsink/gstapexsink.h
+++ b/ext/apexsink/gstapexsink.h
@@ -46,6 +46,8 @@ G_BEGIN_DECLS
 #define GST_APEX_SINK_NAME			"apexsink"
 #define GST_APEX_SINK_JACKTYPE_TYPE		(gst_apexsink_jacktype_get_type())
 #define GST_APEX_SINK_JACKSTATUS_TYPE		(gst_apexsink_jackstatus_get_type())
+#define GST_APEX_SINK_GENERATION_TYPE		(gst_apexsink_generation_get_type())
+#define GST_APEX_SINK_TRANSPORT_PROTOCOL_TYPE	(gst_apexsink_transport_protocol_get_type())
 /* ApEx classes declaration */
 typedef struct _GstApExSink GstApExSink;
 typedef struct _GstApExSinkClass GstApExSinkClass;
@@ -59,10 +61,19 @@ struct _GstApExSink
   gchar *host;
   guint port;
   guint volume;
+  GstApExGeneration generation;
+  GstApExTransportProtocol transport_protocol;
 
-  /* private attributes : latency time local copy, tracks list of the mixer interface */
+  /* private attributes : 
+   * latency time local copy 
+   * tracks list of the mixer interface
+   * clock for sleeping
+   * clock ID for sleeping / canceling sleep
+   */
   guint64 latency_time;
   GList *tracks;
+  GstClock *clock;
+  GstClockID clock_id;
 
   /* private apex client */
   GstApExRAOP *gst_apexraop;
@@ -73,9 +84,11 @@ struct _GstApExSinkClass
   GstAudioSinkClass parent_class;
 };
 
-/* genum jack access */
+/* genums */
 GType gst_apexsink_jackstatus_get_type (void);
 GType gst_apexsink_jacktype_get_type (void);
+GType gst_apexsink_generation_get_type (void);
+GType gst_apexsink_transport_protocol_get_type (void);
 
 /* audio sink standard api */
 GType gst_apexsink_get_type (void);