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gstreamer/gst-libs/gst/app/gstappsink.c

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/* GStreamer
* Copyright (C) 2007 David Schleef <ds@schleef.org>
* (C) 2008 Wim Taymans <wim.taymans@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-appsink
*
* Appsink is a sink plugin that supports many different methods for making
* the application get a handle on the GStreamer data in a pipeline. Unlike
* most GStreamer elements, Appsink provides external API functions.
*
* For the documentation of the API, please see the
* <link linkend="gst-plugins-base-libs-appsink">libgstapp</link> section in
* the GStreamer Plugins Base Libraries documentation.
*
* Since: 0.10.22
*/
/**
* SECTION:gstappsink
* @short_description: Easy way for applications to extract buffers from a
* pipeline
* @see_also: #GstBaseSink, appsrc
*
* Appsink is a sink plugin that supports many different methods for making
* the application get a handle on the GStreamer data in a pipeline. Unlike
* most GStreamer elements, Appsink provides external API functions.
*
* appsink can be used by linking to the gstappsink.h header file to access the
* methods or by using the appsink action signals and properties.
*
* The normal way of retrieving buffers from appsink is by using the
* gst_app_sink_pull_buffer() and gst_app_sink_pull_preroll() methods.
* These methods block until a buffer becomes available in the sink or when the
* sink is shut down or reaches EOS.
*
* Appsink will internally use a queue to collect buffers from the streaming
* thread. If the application is not pulling buffers fast enough, this queue
* will consume a lot of memory over time. The "max-buffers" property can be
* used to limit the queue size. The "drop" property controls whether the
* streaming thread blocks or if older buffers are dropped when the maximum
* queue size is reached. Note that blocking the streaming thread can negatively
* affect real-time performance and should be avoided.
*
* If a blocking behaviour is not desirable, setting the "emit-signals" property
* to %TRUE will make appsink emit the "new-buffer" and "new-preroll" signals
* when a buffer can be pulled without blocking.
*
* The "caps" property on appsink can be used to control the formats that
* appsink can receive. This property can contain non-fixed caps, the format of
* the pulled buffers can be obtained by getting the buffer caps.
*
* If one of the pull-preroll or pull-buffer methods return %NULL, the appsink
* is stopped or in the EOS state. You can check for the EOS state with the
* "eos" property or with the gst_app_sink_is_eos() method.
*
* The eos signal can also be used to be informed when the EOS state is reached
* to avoid polling.
*
* Last reviewed on 2008-12-17 (0.10.22)
*
* Since: 0.10.22
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/base/gstbasesink.h>
#include <gst/gstbuffer.h>
#include <gst/gstbufferlist.h>
#include <string.h>
#include "gstappsink.h"
struct _GstAppSinkPrivate
{
GstCaps *caps;
gboolean emit_signals;
guint max_buffers;
gboolean drop;
GCond *cond;
GMutex *mutex;
GQueue *queue;
GstBuffer *preroll;
gboolean flushing;
gboolean unlock;
gboolean started;
gboolean is_eos;
GstAppSinkCallbacks callbacks;
gpointer user_data;
GDestroyNotify notify;
};
GST_DEBUG_CATEGORY_STATIC (app_sink_debug);
#define GST_CAT_DEFAULT app_sink_debug
enum
{
/* signals */
SIGNAL_EOS,
SIGNAL_NEW_PREROLL,
SIGNAL_NEW_BUFFER,
SIGNAL_NEW_BUFFER_LIST,
/* actions */
SIGNAL_PULL_PREROLL,
SIGNAL_PULL_BUFFER,
SIGNAL_PULL_BUFFER_LIST,
LAST_SIGNAL
};
#define DEFAULT_PROP_EOS TRUE
#define DEFAULT_PROP_EMIT_SIGNALS FALSE
#define DEFAULT_PROP_MAX_BUFFERS 0
#define DEFAULT_PROP_DROP FALSE
enum
{
PROP_0,
PROP_CAPS,
PROP_EOS,
PROP_EMIT_SIGNALS,
PROP_MAX_BUFFERS,
PROP_DROP,
PROP_LAST
};
static GstStaticPadTemplate gst_app_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static void gst_app_sink_uri_handler_init (gpointer g_iface,
gpointer iface_data);
static void gst_app_sink_dispose (GObject * object);
static void gst_app_sink_finalize (GObject * object);
static void gst_app_sink_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
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);
static GstFlowReturn gst_app_sink_preroll (GstBaseSink * psink,
GstBuffer * buffer);
static GstFlowReturn gst_app_sink_render_common (GstBaseSink * psink,
GstMiniObject * data, gboolean is_list);
static GstFlowReturn gst_app_sink_render (GstBaseSink * psink,
GstBuffer * buffer);
static GstFlowReturn gst_app_sink_render_list (GstBaseSink * psink,
GstBufferList * list);
static GstCaps *gst_app_sink_getcaps (GstBaseSink * psink);
static GstMiniObject *gst_app_sink_pull_object (GstAppSink * appsink);
static guint gst_app_sink_signals[LAST_SIGNAL] = { 0 };
static void
_do_init (GType filesrc_type)
{
static const GInterfaceInfo urihandler_info = {
gst_app_sink_uri_handler_init,
NULL,
NULL
};
g_type_add_interface_static (filesrc_type, GST_TYPE_URI_HANDLER,
&urihandler_info);
}
GST_BOILERPLATE_FULL (GstAppSink, gst_app_sink, GstBaseSink, GST_TYPE_BASE_SINK,
_do_init);
/* Can't use glib-genmarshal for this, as it doesn't know how to handle
* GstMiniObject-based types, which are a new fundamental type */
static void
gst_app_marshal_BUFFER__VOID (GClosure * closure,
GValue * return_value,
guint n_param_values,
const GValue * param_values,
gpointer invocation_hint, gpointer marshal_data)
{
typedef GstBuffer *(*GMarshalFunc_BUFFER__VOID) (gpointer data1,
gpointer data2);
register GMarshalFunc_BUFFER__VOID callback;
register GCClosure *cc = (GCClosure *) closure;
register gpointer data1, data2;
GstBuffer *v_return;
g_return_if_fail (return_value != NULL);
g_return_if_fail (n_param_values == 1);
if (G_CCLOSURE_SWAP_DATA (closure)) {
data1 = closure->data;
data2 = g_value_peek_pointer (param_values + 0);
} else {
data1 = g_value_peek_pointer (param_values + 0);
data2 = closure->data;
}
callback =
(GMarshalFunc_BUFFER__VOID) (marshal_data ? marshal_data : cc->callback);
v_return = callback (data1, data2);
gst_value_take_buffer (return_value, v_return);
}
static void
gst_app_sink_base_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
GST_DEBUG_CATEGORY_INIT (app_sink_debug, "appsink", 0, "appsink element");
gst_element_class_set_details_simple (element_class, "AppSink",
"Generic/Sink", "Allow the application to get access to raw buffer",
"David Schleef <ds@schleef.org>, Wim Taymans <wim.taymans@gmail.com>");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_app_sink_template));
}
static void
gst_app_sink_class_init (GstAppSinkClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
GstBaseSinkClass *basesink_class = (GstBaseSinkClass *) klass;
gobject_class->dispose = gst_app_sink_dispose;
gobject_class->finalize = gst_app_sink_finalize;
gobject_class->set_property = gst_app_sink_set_property;
gobject_class->get_property = gst_app_sink_get_property;
g_object_class_install_property (gobject_class, PROP_CAPS,
g_param_spec_boxed ("caps", "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_param_spec_boolean ("eos", "EOS",
"Check if the sink is EOS or not started", DEFAULT_PROP_EOS,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_EMIT_SIGNALS,
g_param_spec_boolean ("emit-signals", "Emit signals",
"Emit new-preroll and new-buffer signals", DEFAULT_PROP_EMIT_SIGNALS,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_MAX_BUFFERS,
g_param_spec_uint ("max-buffers", "Max Buffers",
"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
*
* Signal that the end-of-stream has been reached. This signal is emited from
* the steaming thread.
*/
gst_app_sink_signals[SIGNAL_EOS] =
g_signal_new ("eos", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstAppSinkClass, eos),
NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
/**
* GstAppSink::new-preroll:
* @appsink: the appsink element that emited the signal
*
* Signal that a new preroll buffer is available.
*
* This signal is emited from the steaming thread and only when the
* "emit-signals" property is %TRUE.
*
* The new preroll buffer can be retrieved with the "pull-preroll" action
* signal or gst_app_sink_pull_preroll() either from this signal callback
* or from any other thread.
*
* Note that this signal is only emited when the "emit-signals" property is
* set to %TRUE, which it is not by default for performance reasons.
*/
gst_app_sink_signals[SIGNAL_NEW_PREROLL] =
g_signal_new ("new-preroll", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstAppSinkClass, new_preroll),
NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
/**
* GstAppSink::new-buffer:
* @appsink: the appsink element that emited the signal
*
* Signal that a new buffer is available.
*
* This signal is emited from the steaming thread and only when the
* "emit-signals" property is %TRUE.
*
* The new buffer can be retrieved with the "pull-buffer" action
* signal or gst_app_sink_pull_buffer() either from this signal callback
* or from any other thread.
*
* Note that this signal is only emited when the "emit-signals" property is
* set to %TRUE, which it is not by default for performance reasons.
*/
gst_app_sink_signals[SIGNAL_NEW_BUFFER] =
g_signal_new ("new-buffer", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstAppSinkClass, new_buffer),
NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
/**
* GstAppSink::new-buffer-list:
* @appsink: the appsink element that emited the signal
*
* Signal that a new bufferlist is available.
*
* This signal is emited from the steaming thread and only when the
* "emit-signals" property is %TRUE.
*
* The new buffer can be retrieved with the "pull-buffer-list" action
* signal or gst_app_sink_pull_buffer_list() either from this signal callback
* or from any other thread.
*
* Note that this signal is only emited when the "emit-signals" property is
* set to %TRUE, which it is not by default for performance reasons.
*/
gst_app_sink_signals[SIGNAL_NEW_BUFFER_LIST] =
g_signal_new ("new-buffer-list", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST, G_STRUCT_OFFSET (GstAppSinkClass, new_buffer_list),
NULL, NULL, g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0, G_TYPE_NONE);
/**
* GstAppSink::pull-preroll:
* @appsink: the appsink element to emit this signal on
*
* Get the last preroll buffer in @appsink. This was the buffer that caused the
* appsink to preroll in the PAUSED state. This buffer can be pulled many times
* and remains available to the application even after EOS.
*
* This function is typically used when dealing with a pipeline in the PAUSED
* state. Calling this function after doing a seek will give the buffer right
* after the seek position.
*
* Note that the preroll buffer will also be returned as the first buffer
* when calling gst_app_sink_pull_buffer() or the "pull-buffer" action signal.
*
* 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.
*
* This function blocks until a preroll buffer or EOS is received or the appsink
* element is set to the READY/NULL state.
*
* Returns: a #GstBuffer or NULL when the appsink is stopped or EOS.
*/
gst_app_sink_signals[SIGNAL_PULL_PREROLL] =
g_signal_new ("pull-preroll", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstAppSinkClass,
pull_preroll), NULL, NULL, gst_app_marshal_BUFFER__VOID,
GST_TYPE_BUFFER, 0, G_TYPE_NONE);
/**
* GstAppSink::pull-buffer:
* @appsink: the appsink element to emit this signal on
*
* This function blocks until a buffer or EOS becomes available or the appsink
* element is set to the READY/NULL state.
*
* 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. 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.
*
* Returns: a #GstBuffer or NULL when the appsink is stopped or EOS.
*/
gst_app_sink_signals[SIGNAL_PULL_BUFFER] =
g_signal_new ("pull-buffer", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstAppSinkClass,
pull_buffer), NULL, NULL, gst_app_marshal_BUFFER__VOID,
GST_TYPE_BUFFER, 0, G_TYPE_NONE);
/**
* GstAppSink::pull-buffer-list:
* @appsink: the appsink element to emit this signal on
*
* This function blocks until a buffer list or EOS becomes available or the appsink
* element is set to the READY/NULL state.
*
* This function will only return bufferlists when the appsink is in the PLAYING
* state. All rendered bufferlists will be put in a queue so that the application
* can pull bufferlists at its own rate.
*
* Note that when the application does not pull bufferlists fast enough, the
* queued bufferlists 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.
*
* Returns: a #GstBufferList or NULL when the appsink is stopped or EOS.
*/
gst_app_sink_signals[SIGNAL_PULL_BUFFER_LIST] =
g_signal_new ("pull-buffer-list", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstAppSinkClass,
pull_buffer_list), NULL, NULL, gst_app_marshal_BUFFER__VOID,
GST_TYPE_BUFFER_LIST, 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;
basesink_class->preroll = gst_app_sink_preroll;
basesink_class->render = gst_app_sink_render;
basesink_class->render_list = gst_app_sink_render_list;
basesink_class->get_caps = gst_app_sink_getcaps;
klass->pull_preroll = gst_app_sink_pull_preroll;
klass->pull_buffer = gst_app_sink_pull_buffer;
klass->pull_buffer_list = gst_app_sink_pull_buffer_list;
g_type_class_add_private (klass, sizeof (GstAppSinkPrivate));
}
static void
gst_app_sink_init (GstAppSink * appsink, GstAppSinkClass * klass)
{
GstAppSinkPrivate *priv;
priv = appsink->priv =
G_TYPE_INSTANCE_GET_PRIVATE (appsink, GST_TYPE_APP_SINK,
GstAppSinkPrivate);
priv->mutex = g_mutex_new ();
priv->cond = g_cond_new ();
priv->queue = g_queue_new ();
priv->emit_signals = DEFAULT_PROP_EMIT_SIGNALS;
priv->max_buffers = DEFAULT_PROP_MAX_BUFFERS;
priv->drop = DEFAULT_PROP_DROP;
}
static void
gst_app_sink_dispose (GObject * obj)
{
GstAppSink *appsink = GST_APP_SINK_CAST (obj);
GstAppSinkPrivate *priv = appsink->priv;
GstMiniObject *queue_obj;
GST_OBJECT_LOCK (appsink);
if (priv->caps) {
gst_caps_unref (priv->caps);
priv->caps = NULL;
}
if (priv->notify) {
priv->notify (priv->user_data);
}
priv->user_data = NULL;
priv->notify = NULL;
GST_OBJECT_UNLOCK (appsink);
g_mutex_lock (priv->mutex);
if (priv->preroll) {
gst_buffer_unref (priv->preroll);
priv->preroll = NULL;
}
while ((queue_obj = g_queue_pop_head (priv->queue)))
gst_mini_object_unref (queue_obj);
g_mutex_unlock (priv->mutex);
G_OBJECT_CLASS (parent_class)->dispose (obj);
}
static void
gst_app_sink_finalize (GObject * obj)
{
GstAppSink *appsink = GST_APP_SINK_CAST (obj);
GstAppSinkPrivate *priv = appsink->priv;
g_mutex_free (priv->mutex);
g_cond_free (priv->cond);
g_queue_free (priv->queue);
G_OBJECT_CLASS (parent_class)->finalize (obj);
}
static void
gst_app_sink_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstAppSink *appsink = GST_APP_SINK_CAST (object);
switch (prop_id) {
case PROP_CAPS:
gst_app_sink_set_caps (appsink, gst_value_get_caps (value));
break;
case PROP_EMIT_SIGNALS:
gst_app_sink_set_emit_signals (appsink, g_value_get_boolean (value));
break;
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;
}
}
static void
gst_app_sink_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
GstAppSink *appsink = GST_APP_SINK_CAST (object);
switch (prop_id) {
case PROP_CAPS:
{
GstCaps *caps;
caps = gst_app_sink_get_caps (appsink);
gst_value_set_caps (value, caps);
if (caps)
gst_caps_unref (caps);
break;
}
case PROP_EOS:
g_value_set_boolean (value, gst_app_sink_is_eos (appsink));
break;
case PROP_EMIT_SIGNALS:
g_value_set_boolean (value, gst_app_sink_get_emit_signals (appsink));
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_CAST (bsink);
GstAppSinkPrivate *priv = appsink->priv;
g_mutex_lock (priv->mutex);
GST_DEBUG_OBJECT (appsink, "unlock start");
priv->unlock = TRUE;
g_cond_signal (priv->cond);
g_mutex_unlock (priv->mutex);
return TRUE;
}
static gboolean
gst_app_sink_unlock_stop (GstBaseSink * bsink)
{
GstAppSink *appsink = GST_APP_SINK_CAST (bsink);
GstAppSinkPrivate *priv = appsink->priv;
g_mutex_lock (priv->mutex);
GST_DEBUG_OBJECT (appsink, "unlock stop");
priv->unlock = FALSE;
g_cond_signal (priv->cond);
g_mutex_unlock (priv->mutex);
return TRUE;
}
static void
gst_app_sink_flush_unlocked (GstAppSink * appsink)
{
GstMiniObject *obj;
GstAppSinkPrivate *priv = appsink->priv;
GST_DEBUG_OBJECT (appsink, "flush stop appsink");
priv->is_eos = FALSE;
gst_buffer_replace (&priv->preroll, NULL);
while ((obj = g_queue_pop_head (priv->queue)))
gst_mini_object_unref (obj);
g_cond_signal (priv->cond);
}
static gboolean
gst_app_sink_start (GstBaseSink * psink)
{
GstAppSink *appsink = GST_APP_SINK_CAST (psink);
GstAppSinkPrivate *priv = appsink->priv;
g_mutex_lock (priv->mutex);
GST_DEBUG_OBJECT (appsink, "starting");
priv->started = TRUE;
g_mutex_unlock (priv->mutex);
return TRUE;
}
static gboolean
gst_app_sink_stop (GstBaseSink * psink)
{
GstAppSink *appsink = GST_APP_SINK_CAST (psink);
GstAppSinkPrivate *priv = appsink->priv;
g_mutex_lock (priv->mutex);
GST_DEBUG_OBJECT (appsink, "stopping");
priv->flushing = TRUE;
priv->started = FALSE;
gst_app_sink_flush_unlocked (appsink);
g_mutex_unlock (priv->mutex);
return TRUE;
}
static gboolean
gst_app_sink_event (GstBaseSink * sink, GstEvent * event)
{
GstAppSink *appsink = GST_APP_SINK_CAST (sink);
GstAppSinkPrivate *priv = appsink->priv;
switch (event->type) {
case GST_EVENT_EOS:
g_mutex_lock (priv->mutex);
GST_DEBUG_OBJECT (appsink, "receiving EOS");
priv->is_eos = TRUE;
g_cond_signal (priv->cond);
g_mutex_unlock (priv->mutex);
/* emit EOS now */
if (priv->callbacks.eos)
priv->callbacks.eos (appsink, priv->user_data);
else
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 (priv->mutex);
GST_DEBUG_OBJECT (appsink, "received FLUSH_STOP");
gst_app_sink_flush_unlocked (appsink);
g_mutex_unlock (priv->mutex);
break;
default:
break;
}
return TRUE;
}
static GstFlowReturn
gst_app_sink_preroll (GstBaseSink * psink, GstBuffer * buffer)
{
GstFlowReturn res = GST_FLOW_OK;
GstAppSink *appsink = GST_APP_SINK_CAST (psink);
GstAppSinkPrivate *priv = appsink->priv;
gboolean emit;
g_mutex_lock (priv->mutex);
if (priv->flushing)
goto flushing;
GST_DEBUG_OBJECT (appsink, "setting preroll buffer %p", buffer);
gst_buffer_replace (&priv->preroll, buffer);
g_cond_signal (priv->cond);
emit = priv->emit_signals;
g_mutex_unlock (priv->mutex);
if (priv->callbacks.new_preroll)
res = priv->callbacks.new_preroll (appsink, priv->user_data);
else if (emit)
g_signal_emit (appsink, gst_app_sink_signals[SIGNAL_NEW_PREROLL], 0);
return res;
flushing:
{
GST_DEBUG_OBJECT (appsink, "we are flushing");
g_mutex_unlock (priv->mutex);
return GST_FLOW_WRONG_STATE;
}
}
static GstFlowReturn
gst_app_sink_render_common (GstBaseSink * psink, GstMiniObject * data,
gboolean is_list)
{
GstFlowReturn ret;
GstAppSink *appsink = GST_APP_SINK_CAST (psink);
GstAppSinkPrivate *priv = appsink->priv;
gboolean emit;
restart:
g_mutex_lock (priv->mutex);
if (priv->flushing)
goto flushing;
GST_DEBUG_OBJECT (appsink, "pushing render buffer%s %p on queue (%d)",
is_list ? " list" : "", data, priv->queue->length);
while (priv->max_buffers > 0 && priv->queue->length >= priv->max_buffers) {
if (priv->drop) {
GstMiniObject *obj;
/* we need to drop the oldest buffer/list and try again */
obj = g_queue_pop_head (priv->queue);
GST_DEBUG_OBJECT (appsink, "dropping old buffer/list %p", obj);
gst_mini_object_unref (obj);
} else {
GST_DEBUG_OBJECT (appsink, "waiting for free space, length %d >= %d",
priv->queue->length, priv->max_buffers);
if (priv->unlock) {
/* we are asked to unlock, call the wait_preroll method */
g_mutex_unlock (priv->mutex);
if ((ret = gst_base_sink_wait_preroll (psink)) != GST_FLOW_OK)
goto stopping;
/* we are allowed to continue now */
goto restart;
}
/* wait for a buffer to be removed or flush */
g_cond_wait (priv->cond, priv->mutex);
if (priv->flushing)
goto flushing;
}
}
/* we need to ref the buffer when pushing it in the queue */
g_queue_push_tail (priv->queue, gst_mini_object_ref (data));
g_cond_signal (priv->cond);
emit = priv->emit_signals;
g_mutex_unlock (priv->mutex);
if (is_list) {
if (priv->callbacks.new_buffer_list)
priv->callbacks.new_buffer_list (appsink, priv->user_data);
} else {
if (priv->callbacks.new_buffer)
priv->callbacks.new_buffer (appsink, priv->user_data);
else if (emit)
g_signal_emit (appsink, gst_app_sink_signals[SIGNAL_NEW_BUFFER], 0);
}
return GST_FLOW_OK;
flushing:
{
GST_DEBUG_OBJECT (appsink, "we are flushing");
g_mutex_unlock (priv->mutex);
return GST_FLOW_WRONG_STATE;
}
stopping:
{
GST_DEBUG_OBJECT (appsink, "we are stopping");
return ret;
}
}
static GstFlowReturn
gst_app_sink_render (GstBaseSink * psink, GstBuffer * buffer)
{
return gst_app_sink_render_common (psink, GST_MINI_OBJECT_CAST (buffer),
FALSE);
}
static GstFlowReturn
gst_app_sink_render_list (GstBaseSink * psink, GstBufferList * list)
{
return gst_app_sink_render_common (psink, GST_MINI_OBJECT_CAST (list), TRUE);
}
static GstCaps *
gst_app_sink_getcaps (GstBaseSink * psink)
{
GstCaps *caps;
GstAppSink *appsink = GST_APP_SINK_CAST (psink);
GstAppSinkPrivate *priv = appsink->priv;
GST_OBJECT_LOCK (appsink);
if ((caps = priv->caps))
gst_caps_ref (caps);
GST_DEBUG_OBJECT (appsink, "got caps %" GST_PTR_FORMAT, caps);
GST_OBJECT_UNLOCK (appsink);
return caps;
}
static GstMiniObject *
gst_app_sink_pull_object (GstAppSink * appsink)
{
GstMiniObject *obj = NULL;
GstAppSinkPrivate *priv;
g_return_val_if_fail (GST_IS_APP_SINK (appsink), NULL);
priv = appsink->priv;
g_mutex_lock (priv->mutex);
while (TRUE) {
GST_DEBUG_OBJECT (appsink, "trying to grab a buffer/list");
if (!priv->started)
goto not_started;
if (!g_queue_is_empty (priv->queue))
break;
if (priv->is_eos)
goto eos;
/* nothing to return, wait */
GST_DEBUG_OBJECT (appsink, "waiting for a buffer/list");
g_cond_wait (priv->cond, priv->mutex);
}
obj = g_queue_pop_head (priv->queue);
GST_DEBUG_OBJECT (appsink, "we have a buffer/list %p", obj);
g_cond_signal (priv->cond);
g_mutex_unlock (priv->mutex);
return obj;
/* special conditions */
eos:
{
GST_DEBUG_OBJECT (appsink, "we are EOS, return NULL");
g_mutex_unlock (priv->mutex);
return NULL;
}
not_started:
{
GST_DEBUG_OBJECT (appsink, "we are stopped, return NULL");
g_mutex_unlock (priv->mutex);
return NULL;
}
}
/* external API */
/**
* gst_app_sink_set_caps:
* @appsink: a #GstAppSink
* @caps: caps to set
*
* Set the capabilities on the appsink element. This function takes
* a copy of the caps structure. After calling this method, the sink will only
* accept caps that match @caps. If @caps is non-fixed, you must check the caps
* on the buffers to get the actual used caps.
*
* Since: 0.10.22
*/
void
gst_app_sink_set_caps (GstAppSink * appsink, const GstCaps * caps)
{
GstCaps *old;
GstAppSinkPrivate *priv;
g_return_if_fail (GST_IS_APP_SINK (appsink));
priv = appsink->priv;
GST_OBJECT_LOCK (appsink);
GST_DEBUG_OBJECT (appsink, "setting caps to %" GST_PTR_FORMAT, caps);
if ((old = priv->caps) != caps) {
if (caps)
priv->caps = gst_caps_copy (caps);
else
priv->caps = NULL;
if (old)
gst_caps_unref (old);
}
GST_OBJECT_UNLOCK (appsink);
}
/**
* gst_app_sink_get_caps:
* @appsink: a #GstAppSink
*
* Get the configured caps on @appsink.
*
* Returns: the #GstCaps accepted by the sink. gst_caps_unref() after usage.
*
* Since: 0.10.22
*/
GstCaps *
gst_app_sink_get_caps (GstAppSink * appsink)
{
GstCaps *caps;
GstAppSinkPrivate *priv;
g_return_val_if_fail (GST_IS_APP_SINK (appsink), NULL);
priv = appsink->priv;
GST_OBJECT_LOCK (appsink);
if ((caps = priv->caps))
gst_caps_ref (caps);
GST_DEBUG_OBJECT (appsink, "getting caps of %" GST_PTR_FORMAT, caps);
GST_OBJECT_UNLOCK (appsink);
return caps;
}
/**
* gst_app_sink_is_eos:
* @appsink: a #GstAppSink
*
* Check if @appsink is EOS, which is when no more buffers can be pulled because
* an EOS event was received.
*
* This function also returns %TRUE when the appsink is not in the PAUSED or
* PLAYING state.
*
* Returns: %TRUE if no more buffers can be pulled and the appsink is EOS.
*
* Since: 0.10.22
*/
gboolean
gst_app_sink_is_eos (GstAppSink * appsink)
{
gboolean ret;
GstAppSinkPrivate *priv;
g_return_val_if_fail (GST_IS_APP_SINK (appsink), FALSE);
priv = appsink->priv;
g_mutex_lock (priv->mutex);
if (!priv->started)
goto not_started;
if (priv->is_eos && g_queue_is_empty (priv->queue)) {
GST_DEBUG_OBJECT (appsink, "we are EOS and the queue is empty");
ret = TRUE;
} else {
GST_DEBUG_OBJECT (appsink, "we are not yet EOS");
ret = FALSE;
}
g_mutex_unlock (priv->mutex);
return ret;
not_started:
{
GST_DEBUG_OBJECT (appsink, "we are stopped, return TRUE");
g_mutex_unlock (priv->mutex);
return TRUE;
}
}
/**
* gst_app_sink_set_emit_signals:
* @appsink: a #GstAppSink
* @emit: the new state
*
* Make appsink emit the "new-preroll" and "new-buffer" signals. This option is
* by default disabled because signal emission is expensive and unneeded when
* the application prefers to operate in pull mode.
*
* Since: 0.10.22
*/
void
gst_app_sink_set_emit_signals (GstAppSink * appsink, gboolean emit)
{
GstAppSinkPrivate *priv;
g_return_if_fail (GST_IS_APP_SINK (appsink));
priv = appsink->priv;
g_mutex_lock (priv->mutex);
priv->emit_signals = emit;
g_mutex_unlock (priv->mutex);
}
/**
* gst_app_sink_get_emit_signals:
* @appsink: a #GstAppSink
*
* Check if appsink will emit the "new-preroll" and "new-buffer" signals.
*
* Returns: %TRUE if @appsink is emiting the "new-preroll" and "new-buffer"
* signals.
*
* Since: 0.10.22
*/
gboolean
gst_app_sink_get_emit_signals (GstAppSink * appsink)
{
gboolean result;
GstAppSinkPrivate *priv;
g_return_val_if_fail (GST_IS_APP_SINK (appsink), FALSE);
priv = appsink->priv;
g_mutex_lock (priv->mutex);
result = priv->emit_signals;
g_mutex_unlock (priv->mutex);
return result;
}
/**
* gst_app_sink_set_max_buffers:
* @appsink: a #GstAppSink
* @max: the maximum number of buffers to queue
*
* Set the maximum amount of buffers that can be queued in @appsink. After this
* amount of buffers are queued in appsink, any more buffers will block upstream
* elements until a buffer is pulled from @appsink.
*
* Since: 0.10.22
*/
void
gst_app_sink_set_max_buffers (GstAppSink * appsink, guint max)
{
GstAppSinkPrivate *priv;
g_return_if_fail (GST_IS_APP_SINK (appsink));
priv = appsink->priv;
g_mutex_lock (priv->mutex);
if (max != priv->max_buffers) {
priv->max_buffers = max;
/* signal the change */
g_cond_signal (priv->cond);
}
g_mutex_unlock (priv->mutex);
}
/**
* gst_app_sink_get_max_buffers:
* @appsink: a #GstAppSink
*
* Get the maximum amount of buffers that can be queued in @appsink.
*
* Returns: The maximum amount of buffers that can be queued.
*
* Since: 0.10.22
*/
guint
gst_app_sink_get_max_buffers (GstAppSink * appsink)
{
guint result;
GstAppSinkPrivate *priv;
g_return_val_if_fail (GST_IS_APP_SINK (appsink), 0);
priv = appsink->priv;
g_mutex_lock (priv->mutex);
result = priv->max_buffers;
g_mutex_unlock (priv->mutex);
return result;
}
/**
* gst_app_sink_set_drop:
* @appsink: a #GstAppSink
* @drop: the new state
*
* Instruct @appsink to drop old buffers when the maximum amount of queued
* buffers is reached.
*
* Since: 0.10.22
*/
void
gst_app_sink_set_drop (GstAppSink * appsink, gboolean drop)
{
GstAppSinkPrivate *priv;
g_return_if_fail (GST_IS_APP_SINK (appsink));
priv = appsink->priv;
g_mutex_lock (priv->mutex);
if (priv->drop != drop) {
priv->drop = drop;
/* signal the change */
g_cond_signal (priv->cond);
}
g_mutex_unlock (priv->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.
*
* Since: 0.10.22
*/
gboolean
gst_app_sink_get_drop (GstAppSink * appsink)
{
gboolean result;
GstAppSinkPrivate *priv;
g_return_val_if_fail (GST_IS_APP_SINK (appsink), FALSE);
priv = appsink->priv;
g_mutex_lock (priv->mutex);
result = priv->drop;
g_mutex_unlock (priv->mutex);
return result;
}
/**
* gst_app_sink_pull_preroll:
* @appsink: a #GstAppSink
*
* Get the last preroll buffer in @appsink. This was the buffer that caused the
* appsink to preroll in the PAUSED state. This buffer can be pulled many times
* and remains available to the application even after EOS.
*
* This function is typically used when dealing with a pipeline in the PAUSED
* state. Calling this function after doing a seek will give the buffer right
* after the seek position.
*
* Note that the preroll buffer will also be returned as the first buffer
* when calling gst_app_sink_pull_buffer().
*
* 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.
*
* This function blocks until a preroll buffer or EOS is received or the appsink
* element is set to the READY/NULL state.
*
* Returns: a #GstBuffer or NULL when the appsink is stopped or EOS.
*
* Since: 0.10.22
*/
GstBuffer *
gst_app_sink_pull_preroll (GstAppSink * appsink)
{
GstBuffer *buf = NULL;
GstAppSinkPrivate *priv;
g_return_val_if_fail (GST_IS_APP_SINK (appsink), NULL);
priv = appsink->priv;
g_mutex_lock (priv->mutex);
while (TRUE) {
GST_DEBUG_OBJECT (appsink, "trying to grab a buffer");
if (!priv->started)
goto not_started;
if (priv->preroll != NULL)
break;
if (priv->is_eos)
goto eos;
/* nothing to return, wait */
GST_DEBUG_OBJECT (appsink, "waiting for the preroll buffer");
g_cond_wait (priv->cond, priv->mutex);
}
buf = gst_buffer_ref (priv->preroll);
GST_DEBUG_OBJECT (appsink, "we have the preroll buffer %p", buf);
g_mutex_unlock (priv->mutex);
return buf;
/* special conditions */
eos:
{
GST_DEBUG_OBJECT (appsink, "we are EOS, return NULL");
g_mutex_unlock (priv->mutex);
return NULL;
}
not_started:
{
GST_DEBUG_OBJECT (appsink, "we are stopped, return NULL");
g_mutex_unlock (priv->mutex);
return NULL;
}
}
/**
* gst_app_sink_pull_buffer:
* @appsink: a #GstAppSink
*
* This function blocks until a buffer or EOS becomes available or the appsink
* element is set to the READY/NULL state.
*
* 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.
*
* 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.
*
* Returns: a #GstBuffer or NULL when the appsink is stopped or EOS.
*
* Since: 0.10.22
*/
GstBuffer *
gst_app_sink_pull_buffer (GstAppSink * appsink)
{
GST_DEBUG_OBJECT (appsink, "pull a buffer");
return GST_BUFFER_CAST (gst_app_sink_pull_object (appsink));
}
/**
* gst_app_sink_pull_buffer_list:
* @appsink: a #GstAppSink
*
* This function blocks until a buffer list or EOS becomes available or the
* appsink element is set to the READY/NULL state.
*
* This function will only return buffer lists when the appsink is in the
* PLAYING state. All rendered buffer lists will be put in a queue so that
* the application can pull buffer lists at its own rate. Note that when
* the application does not pull buffer lists fast enough, the queued buffer
* lists could consume a lot of memory, especially when dealing with raw
* video frames.
*
* If an EOS event was received before any buffer lists, this function returns
* %NULL. Use gst_app_sink_is_eos () to check for the EOS condition.
*
* Returns: a #GstBufferList or NULL when the appsink is stopped or EOS.
*/
GstBufferList *
gst_app_sink_pull_buffer_list (GstAppSink * appsink)
{
GST_DEBUG_OBJECT (appsink, "pull a buffer list");
return GST_BUFFER_LIST_CAST (gst_app_sink_pull_object (appsink));
}
/**
* gst_app_sink_set_callbacks:
* @appsink: a #GstAppSink
* @callbacks: the callbacks
* @user_data: a user_data argument for the callbacks
* @notify: a destroy notify function
*
* Set callbacks which will be executed for each new preroll, new buffer and eos.
* This is an alternative to using the signals, it has lower overhead and is thus
* less expensive, but also less flexible.
*
* If callbacks are installed, no signals will be emited for performance
* reasons.
*
* Since: 0.10.23
*/
void
gst_app_sink_set_callbacks (GstAppSink * appsink,
GstAppSinkCallbacks * callbacks, gpointer user_data, GDestroyNotify notify)
{
GDestroyNotify old_notify;
GstAppSinkPrivate *priv;
g_return_if_fail (GST_IS_APP_SINK (appsink));
g_return_if_fail (callbacks != NULL);
priv = appsink->priv;
GST_OBJECT_LOCK (appsink);
old_notify = priv->notify;
if (old_notify) {
gpointer old_data;
old_data = priv->user_data;
priv->user_data = NULL;
priv->notify = NULL;
GST_OBJECT_UNLOCK (appsink);
old_notify (old_data);
GST_OBJECT_LOCK (appsink);
}
priv->callbacks = *callbacks;
priv->user_data = user_data;
priv->notify = notify;
GST_OBJECT_UNLOCK (appsink);
}
/*** GSTURIHANDLER INTERFACE *************************************************/
static GstURIType
gst_app_sink_uri_get_type (void)
{
return GST_URI_SINK;
}
static gchar **
gst_app_sink_uri_get_protocols (void)
{
static gchar *protocols[] = { (char *) "appsink", NULL };
return protocols;
}
static const gchar *
gst_app_sink_uri_get_uri (GstURIHandler * handler)
{
return "appsink";
}
static gboolean
gst_app_sink_uri_set_uri (GstURIHandler * handler, const gchar * uri)
{
gchar *protocol;
gboolean ret;
protocol = gst_uri_get_protocol (uri);
ret = !strcmp (protocol, "appsink");
g_free (protocol);
return ret;
}
static void
gst_app_sink_uri_handler_init (gpointer g_iface, gpointer iface_data)
{
GstURIHandlerInterface *iface = (GstURIHandlerInterface *) g_iface;
iface->get_type = gst_app_sink_uri_get_type;
iface->get_protocols = gst_app_sink_uri_get_protocols;
iface->get_uri = gst_app_sink_uri_get_uri;
iface->set_uri = gst_app_sink_uri_set_uri;
}
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