basesink: add simple rate control

Add a max-bitrate property that will slightly delay rendering of buffers if it
would exceed the maximum defined bitrate. This can be used to do
rate control on network sinks, for example.

API: GstBaseSink::max-bitrate
API: gst_base_sink_set_max_bitrate()
API: gst_base_sink_get_max_bitrate()

diff --git a/libs/gst/base/gstbasesink.c b/libs/gst/base/gstbasesink.c
index 40e8008..f69c7fa 100644 (file)
--- a/libs/gst/base/gstbasesink.c
+++ b/libs/gst/base/gstbasesink.c
@@ -265,6 +265,12 @@ struct _GstBaseSinkPrivate
   /* for throttling and QoS */
   GstClockTime earliest_in_time;
   GstClockTime throttle_time;
+
+  /* for rate control */
+  guint64 max_bitrate;
+  GstClockTime rc_time;
+  GstClockTime rc_next;
+  gsize rc_accumulated;
 };
 
 #define DO_RUNNING_AVG(avg,val,size) (((val) + ((size)-1) * (avg)) / (size))
@@ -292,6 +298,7 @@ struct _GstBaseSinkPrivate
 #define DEFAULT_RENDER_DELAY        0
 #define DEFAULT_ENABLE_LAST_SAMPLE  TRUE
 #define DEFAULT_THROTTLE_TIME       0
+#define DEFAULT_MAX_BITRATE         0
 
 enum
 {
@@ -306,6 +313,7 @@ enum
   PROP_BLOCKSIZE,
   PROP_RENDER_DELAY,
   PROP_THROTTLE_TIME,
+  PROP_MAX_BITRATE,
   PROP_LAST
 };
 
@@ -511,8 +519,23 @@ gst_base_sink_class_init (GstBaseSinkClass * klass)
    */
   g_object_class_install_property (gobject_class, PROP_THROTTLE_TIME,
       g_param_spec_uint64 ("throttle-time", "Throttle time",
-          "The time to keep between rendered buffers", 0, G_MAXUINT64,
-          DEFAULT_THROTTLE_TIME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+          "The time to keep between rendered buffers (0 = disabled)", 0,
+          G_MAXUINT64, DEFAULT_THROTTLE_TIME,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+  /**
+   * GstBaseSink:max-bitrate:
+   *
+   * Control the maximum amount of bits that will be rendered per second.
+   * Setting this property to a value bigger than 0 will make the sink delay
+   * rendering of the buffers when it would exceed to max-bitrate.
+   *
+   * Since: 1.1.1
+   */
+  g_object_class_install_property (gobject_class, PROP_MAX_BITRATE,
+      g_param_spec_uint64 ("max-bitrate", "Max Bitrate",
+          "The maximum bits per second to render (0 = disabled)", 0,
+          G_MAXUINT64, DEFAULT_MAX_BITRATE,
+          G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   gstelement_class->change_state =
       GST_DEBUG_FUNCPTR (gst_base_sink_change_state);
@@ -643,6 +666,7 @@ gst_base_sink_init (GstBaseSink * basesink, gpointer g_class)
   priv->cached_clock_id = NULL;
   g_atomic_int_set (&priv->enable_last_sample, DEFAULT_ENABLE_LAST_SAMPLE);
   priv->throttle_time = DEFAULT_THROTTLE_TIME;
+  priv->max_bitrate = DEFAULT_MAX_BITRATE;
 
   GST_OBJECT_FLAG_SET (basesink, GST_ELEMENT_FLAG_SINK);
 }
@@ -1249,6 +1273,50 @@ gst_base_sink_get_throttle_time (GstBaseSink * sink)
   return res;
 }
 
+/**
+ * gst_base_sink_set_max_bitrate:
+ * @sink: a #GstBaseSink
+ * @max_bitrate: the max_bitrate in bits per second
+ *
+ * Set the maximum amount of bits per second that the sink will render.
+ *
+ * Since: 1.1.1
+ */
+void
+gst_base_sink_set_max_bitrate (GstBaseSink * sink, guint64 max_bitrate)
+{
+  g_return_if_fail (GST_IS_BASE_SINK (sink));
+
+  GST_OBJECT_LOCK (sink);
+  sink->priv->max_bitrate = max_bitrate;
+  GST_LOG_OBJECT (sink, "set max_bitrate to %" G_GUINT64_FORMAT, max_bitrate);
+  GST_OBJECT_UNLOCK (sink);
+}
+
+/**
+ * gst_base_sink_get_max_bitrate:
+ * @sink: a #GstBaseSink
+ *
+ * Get the maximum amount of bits per second that the sink will render.
+ *
+ * Returns: the maximum number of bits per second @sink will render.
+ *
+ * Since: 1.1.1
+ */
+guint64
+gst_base_sink_get_max_bitrate (GstBaseSink * sink)
+{
+  guint64 res;
+
+  g_return_val_if_fail (GST_IS_BASE_SINK (sink), 0);
+
+  GST_OBJECT_LOCK (sink);
+  res = sink->priv->max_bitrate;
+  GST_OBJECT_UNLOCK (sink);
+
+  return res;
+}
+
 static void
 gst_base_sink_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec)
@@ -1283,6 +1351,9 @@ gst_base_sink_set_property (GObject * object, guint prop_id,
     case PROP_THROTTLE_TIME:
       gst_base_sink_set_throttle_time (sink, g_value_get_uint64 (value));
       break;
+    case PROP_MAX_BITRATE:
+      gst_base_sink_set_max_bitrate (sink, g_value_get_uint64 (value));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -1326,6 +1397,9 @@ gst_base_sink_get_property (GObject * object, guint prop_id, GValue * value,
     case PROP_THROTTLE_TIME:
       g_value_set_uint64 (value, gst_base_sink_get_throttle_time (sink));
       break;
+    case PROP_MAX_BITRATE:
+      g_value_set_uint64 (value, gst_base_sink_get_max_bitrate (sink));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -2362,6 +2436,18 @@ again:
   /* adjust for latency */
   stime = gst_base_sink_adjust_time (basesink, rstart);
 
+  /* adjust for rate control */
+  if (priv->rc_next == -1 || (stime != -1 && stime >= priv->rc_next)) {
+    GST_DEBUG_OBJECT (basesink, "reset rc_time to time %" GST_TIME_FORMAT,
+        GST_TIME_ARGS (stime));
+    priv->rc_time = stime;
+    priv->rc_accumulated = 0;
+  } else {
+    GST_DEBUG_OBJECT (basesink, "rate control next %" GST_TIME_FORMAT,
+        GST_TIME_ARGS (priv->rc_next));
+    stime = priv->rc_next;
+  }
+
   /* preroll done, we can sync since we are in PLAYING now. */
   GST_DEBUG_OBJECT (basesink, "possibly waiting for clock to reach %"
       GST_TIME_FORMAT ", adjusted %" GST_TIME_FORMAT,
@@ -3085,6 +3171,13 @@ gst_base_sink_needs_preroll (GstBaseSink * basesink)
   return res;
 }
 
+static gboolean
+count_list_bytes (GstBuffer ** buffer, guint idx, GstBaseSinkPrivate * priv)
+{
+  priv->rc_accumulated += gst_buffer_get_size (*buffer);
+  return TRUE;
+}
+
 /* with STREAM_LOCK, PREROLL_LOCK
  *
  * Takes a buffer and compare the timestamps with the last segment.
@@ -3194,6 +3287,17 @@ again:
   if (G_UNLIKELY (late))
     goto dropped;
 
+  if (priv->max_bitrate) {
+    if (is_list) {
+      gst_buffer_list_foreach (GST_BUFFER_LIST_CAST (obj),
+          (GstBufferListFunc) count_list_bytes, priv);
+    } else {
+      priv->rc_accumulated += gst_buffer_get_size (GST_BUFFER_CAST (obj));
+    }
+    priv->rc_next = priv->rc_time + gst_util_uint64_scale (priv->rc_accumulated,
+        8 * GST_SECOND, priv->max_bitrate);
+  }
+
   /* read once, to get same value before and after */
   do_qos = g_atomic_int_get (&priv->qos_enabled);
 
@@ -4669,6 +4773,7 @@ gst_base_sink_change_state (GstElement * element, GstStateChange transition)
       basesink->eos = FALSE;
       priv->received_eos = FALSE;
       gst_base_sink_reset_qos (basesink);
+      priv->rc_next = -1;
       priv->commited = FALSE;
       priv->call_preroll = TRUE;
       priv->current_step.valid = FALSE;

diff --git a/libs/gst/base/gstbasesink.h b/libs/gst/base/gstbasesink.h
index 15ac9e5..6f2ade7 100644 (file)
--- a/libs/gst/base/gstbasesink.h
+++ b/libs/gst/base/gstbasesink.h
@@ -245,6 +245,10 @@ guint           gst_base_sink_get_blocksize     (GstBaseSink *sink);
 void            gst_base_sink_set_throttle_time (GstBaseSink *sink, guint64 throttle);
 guint64         gst_base_sink_get_throttle_time (GstBaseSink *sink);
 
+/* max-bitrate */
+void            gst_base_sink_set_max_bitrate   (GstBaseSink *sink, guint64 max_bitrate);
+guint64         gst_base_sink_get_max_bitrate   (GstBaseSink *sink);
+
 GstClockReturn  gst_base_sink_wait_clock        (GstBaseSink *sink, GstClockTime time,
                                                  GstClockTimeDiff * jitter);
 GstFlowReturn   gst_base_sink_wait              (GstBaseSink *sink, GstClockTime time,