* Boston, MA 02111-1307, USA.
*/
+/**
+ * SECTION:element-appsink
+ * @short_description: hand data to an application
+ * @see_also: #GstBaseSrc
+ *
+ * <refsect2>
+ * <para>
+ * Appsink is a sink plugin that supports many different methods for making
+ * the application get a handle on the GStreamer data in a pipeline.
+ * </para>
+ * </refsect2>
+ *
+ * Last reviewed on 2008-05-03 (0.10.8)
+ */
+
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
};
#define DEFAULT_PROP_EOS TRUE
-#define DEFAULT_PROP_EMIT_SIGNALS TRUE
+#define DEFAULT_PROP_EMIT_SIGNALS FALSE
#define DEFAULT_PROP_MAX_BUFFERS 0
+#define DEFAULT_PROP_DROP FALSE
enum
{
PROP_EOS,
PROP_EMIT_SIGNALS,
PROP_MAX_BUFFERS,
-
- PROP_LAST,
+ PROP_DROP,
+ PROP_LAST
};
static GstStaticPadTemplate gst_app_sink_template =
static void gst_app_sink_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
+static gboolean gst_app_sink_unlock_start (GstBaseSink * bsink);
+static gboolean gst_app_sink_unlock_stop (GstBaseSink * bsink);
static gboolean gst_app_sink_start (GstBaseSink * psink);
static gboolean gst_app_sink_stop (GstBaseSink * psink);
static gboolean gst_app_sink_event (GstBaseSink * sink, GstEvent * event);
g_object_class_install_property (gobject_class, PROP_CAPS,
g_param_spec_boxed ("caps", "Caps",
- "The caps of the sink pad", GST_TYPE_CAPS,
+ "The allowed caps for the sink pad", GST_TYPE_CAPS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_EOS,
g_object_class_install_property (gobject_class, PROP_MAX_BUFFERS,
g_param_spec_uint ("max-buffers", "Max Buffers",
- "Control the maximum buffers to queue internally (0 = unlimited)",
+ "The maximum number of buffers to queue internally (0 = unlimited)",
0, G_MAXUINT, DEFAULT_PROP_MAX_BUFFERS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+ g_object_class_install_property (gobject_class, PROP_DROP,
+ g_param_spec_boolean ("drop", "Drop",
+ "Drop old buffers when the buffer queue is filled", DEFAULT_PROP_DROP,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+
/**
* GstAppSink::eos:
* @appsink: the appsink element that emited the signal
*
* This function will only return buffers when the appsink is in the PLAYING
* state. All rendered buffers will be put in a queue so that the application
- * can pull buffers at its own rate. Note that when the application does not
- * pull buffers fast enough, the queued buffers could consume a lot of memory,
- * especially when dealing with raw video frames.
+ * can pull buffers at its own rate.
+ *
+ * Note that when the application does not pull buffers fast enough, the
+ * queued buffers could consume a lot of memory, especially when dealing with
+ * raw video frames. It's possible to control the behaviour of the queue with
+ * the "drop" and "max-buffers" properties.
*
* If an EOS event was received before any buffers, this function returns
* %NULL. Use gst_app_sink_is_eos () to check for the EOS condition.
pull_buffer), NULL, NULL, gst_app_marshal_OBJECT__VOID,
GST_TYPE_BUFFER, 0, G_TYPE_NONE);
+ basesink_class->unlock = gst_app_sink_unlock_start;
+ basesink_class->unlock_stop = gst_app_sink_unlock_stop;
basesink_class->start = gst_app_sink_start;
basesink_class->stop = gst_app_sink_stop;
basesink_class->event = gst_app_sink_event;
appsink->emit_signals = DEFAULT_PROP_EMIT_SIGNALS;
appsink->max_buffers = DEFAULT_PROP_MAX_BUFFERS;
+ appsink->drop = DEFAULT_PROP_DROP;
}
static void
case PROP_MAX_BUFFERS:
gst_app_sink_set_max_buffers (appsink, g_value_get_uint (value));
break;
+ case PROP_DROP:
+ gst_app_sink_set_drop (appsink, g_value_get_boolean (value));
+ break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
case PROP_MAX_BUFFERS:
g_value_set_uint (value, gst_app_sink_get_max_buffers (appsink));
break;
+ case PROP_DROP:
+ g_value_set_boolean (value, gst_app_sink_get_drop (appsink));
+ break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
+static gboolean
+gst_app_sink_unlock_start (GstBaseSink * bsink)
+{
+ GstAppSink *appsink = GST_APP_SINK (bsink);
+
+ g_mutex_lock (appsink->mutex);
+ GST_DEBUG_OBJECT (appsink, "unlock start");
+ appsink->flushing = TRUE;
+ g_cond_signal (appsink->cond);
+ g_mutex_unlock (appsink->mutex);
+
+ return TRUE;
+}
+
+static gboolean
+gst_app_sink_unlock_stop (GstBaseSink * bsink)
+{
+ GstAppSink *appsink = GST_APP_SINK (bsink);
+
+ g_mutex_lock (appsink->mutex);
+ GST_DEBUG_OBJECT (appsink, "unlock stop");
+ appsink->flushing = FALSE;
+ g_cond_signal (appsink->cond);
+ g_mutex_unlock (appsink->mutex);
+
+ return TRUE;
+}
+
static void
gst_app_sink_flush_unlocked (GstAppSink * appsink)
{
GstBuffer *buffer;
- GST_DEBUG_OBJECT (appsink, "flushing appsink");
+ GST_DEBUG_OBJECT (appsink, "flush stop appsink");
appsink->is_eos = FALSE;
gst_buffer_replace (&appsink->preroll, NULL);
while ((buffer = g_queue_pop_head (appsink->queue)))
GstAppSink *appsink = GST_APP_SINK (psink);
g_mutex_lock (appsink->mutex);
- appsink->is_eos = FALSE;
- appsink->started = TRUE;
GST_DEBUG_OBJECT (appsink, "starting");
+ appsink->started = TRUE;
g_mutex_unlock (appsink->mutex);
return TRUE;
g_mutex_lock (appsink->mutex);
GST_DEBUG_OBJECT (appsink, "stopping");
+ appsink->is_eos = FALSE;
+ appsink->flushing = TRUE;
appsink->started = FALSE;
gst_app_sink_flush_unlocked (appsink);
g_mutex_unlock (appsink->mutex);
g_signal_emit (appsink, gst_app_sink_signals[SIGNAL_EOS], 0);
break;
case GST_EVENT_FLUSH_START:
+ /* we don't have to do anything here, the base class will call unlock
+ * which will make sure we exit the _render method */
+ GST_DEBUG_OBJECT (appsink, "received FLUSH_START");
break;
case GST_EVENT_FLUSH_STOP:
g_mutex_lock (appsink->mutex);
gboolean emit;
g_mutex_lock (appsink->mutex);
+ if (appsink->flushing)
+ goto flushing;
+
GST_DEBUG_OBJECT (appsink, "setting preroll buffer %p", buffer);
gst_buffer_replace (&appsink->preroll, buffer);
g_cond_signal (appsink->cond);
g_signal_emit (appsink, gst_app_sink_signals[SIGNAL_NEW_PREROLL], 0);
return GST_FLOW_OK;
+
+flushing:
+ {
+ GST_DEBUG_OBJECT (appsink, "we are flushing");
+ g_mutex_unlock (appsink->mutex);
+ return GST_FLOW_WRONG_STATE;
+ }
}
static GstFlowReturn
gboolean emit;
g_mutex_lock (appsink->mutex);
- GST_DEBUG_OBJECT (appsink, "pushing render buffer %p on queue", buffer);
+ if (appsink->flushing)
+ goto flushing;
+
+ GST_DEBUG_OBJECT (appsink, "pushing render buffer %p on queue (%d)",
+ buffer, appsink->queue->length);
while (appsink->max_buffers > 0 &&
appsink->queue->length >= appsink->max_buffers) {
- /* FIXME, do proper unlocking when flushing */
- g_cond_wait (appsink->cond, appsink->mutex);
- if (!appsink->started)
- goto not_started;
+ if (appsink->drop) {
+ GstBuffer *buf;
+
+ /* we need to drop the oldest buffer and try again */
+ buf = g_queue_pop_head (appsink->queue);
+ GST_DEBUG_OBJECT (appsink, "dropping old buffer %p", buf);
+ gst_buffer_unref (buf);
+ } else {
+ GST_DEBUG_OBJECT (appsink, "waiting for free space, length %d >= %d",
+ appsink->queue->length, appsink->max_buffers);
+ /* wait for a buffer to be removed or flush */
+ g_cond_wait (appsink->cond, appsink->mutex);
+ if (appsink->flushing)
+ goto flushing;
+ }
}
+ /* we need to ref the buffer when pushing it in the queue */
g_queue_push_tail (appsink->queue, gst_buffer_ref (buffer));
g_cond_signal (appsink->cond);
emit = appsink->emit_signals;
return GST_FLOW_OK;
-not_started:
+flushing:
{
- GST_DEBUG_OBJECT (appsink, "we stopped");
+ GST_DEBUG_OBJECT (appsink, "we are flushing");
g_mutex_unlock (appsink->mutex);
return GST_FLOW_WRONG_STATE;
}
GST_OBJECT_LOCK (appsink);
GST_DEBUG_OBJECT (appsink, "setting caps to %" GST_PTR_FORMAT, caps);
- old = appsink->caps;
- if (caps)
- appsink->caps = gst_caps_copy (caps);
- else
- appsink->caps = NULL;
- if (old)
- gst_caps_unref (old);
+ if ((old = appsink->caps) != caps) {
+ if (caps)
+ appsink->caps = gst_caps_copy (caps);
+ else
+ appsink->caps = NULL;
+ if (old)
+ gst_caps_unref (old);
+ }
GST_OBJECT_UNLOCK (appsink);
}
}
/**
+ * gst_app_sink_set_drop:
+ * @appsink: a #GstAppSink
+ * @emit: the new state
+ *
+ * Instruct @appsink to drop old buffers when the maximum amount of queued
+ * buffers is reached.
+ */
+void
+gst_app_sink_set_drop (GstAppSink * appsink, gboolean drop)
+{
+ g_return_if_fail (GST_IS_APP_SINK (appsink));
+
+ g_mutex_lock (appsink->mutex);
+ if (appsink->drop != drop) {
+ appsink->drop = drop;
+ /* signal the change */
+ g_cond_signal (appsink->cond);
+ }
+ g_mutex_unlock (appsink->mutex);
+}
+
+/**
+ * gst_app_sink_get_drop:
+ * @appsink: a #GstAppSink
+ *
+ * Check if @appsink will drop old buffers when the maximum amount of queued
+ * buffers is reached.
+ *
+ * Returns: %TRUE if @appsink is dropping old buffers when the queue is
+ * filled.
+ */
+gboolean
+gst_app_sink_get_drop (GstAppSink * appsink)
+{
+ gboolean result;
+
+ g_return_val_if_fail (GST_IS_APP_SINK (appsink), FALSE);
+
+ g_mutex_lock (appsink->mutex);
+ result = appsink->drop;
+ g_mutex_unlock (appsink->mutex);
+
+ return result;
+}
+
+/**
* gst_app_sink_pull_preroll:
* @appsink: a #GstAppSink
*
projects / platform / upstream / gst-plugins-base.git / commitdiff