gstreamer/gst-libs/gst/app/gstappsink.c
Sebastian Dröge ce8d261cd6 appsink: Only emit EOS signal after all buffers are consumed
Otherwise the application will possibly shut down the pipeline already
because EOS is received, while there are still some buffers pending.
2015-01-20 19:22:15 +01:00

1326 lines
37 KiB
C

/* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstappsink
* @short_description: Easy way for applications to extract samples from a
* pipeline
* @see_also: #GstSample, #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 samples from appsink is by using the
* gst_app_sink_pull_sample() and gst_app_sink_pull_preroll() methods.
* These methods block until a sample 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 samples 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-sample" and "new-preroll" signals
* when a sample 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 samples can be obtained by getting the sample caps.
*
* If one of the pull-preroll or pull-sample 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/base/gstbasesink.h>
#include <gst/gstbuffer.h>
#include <string.h>
#include "gstapp-marshal.h"
#include "gstappsink.h"
struct _GstAppSinkPrivate
{
GstCaps *caps;
gboolean emit_signals;
guint num_buffers;
guint max_buffers;
gboolean drop;
GCond cond;
GMutex mutex;
GQueue *queue;
GstBuffer *preroll;
GstCaps *preroll_caps;
GstCaps *last_caps;
GstSegment last_segment;
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_SAMPLE,
/* actions */
SIGNAL_PULL_PREROLL,
SIGNAL_PULL_SAMPLE,
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 gboolean gst_app_sink_query (GstBaseSink * bsink, GstQuery * query);
static GstFlowReturn gst_app_sink_preroll (GstBaseSink * psink,
GstBuffer * buffer);
static GstFlowReturn gst_app_sink_render (GstBaseSink * psink,
GstBuffer * buffer);
static gboolean gst_app_sink_setcaps (GstBaseSink * sink, GstCaps * caps);
static GstCaps *gst_app_sink_getcaps (GstBaseSink * psink, GstCaps * filter);
static guint gst_app_sink_signals[LAST_SIGNAL] = { 0 };
#define gst_app_sink_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstAppSink, gst_app_sink, GST_TYPE_BASE_SINK,
G_IMPLEMENT_INTERFACE (GST_TYPE_URI_HANDLER,
gst_app_sink_uri_handler_init));
static void
gst_app_sink_class_init (GstAppSinkClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
GstElementClass *element_class = (GstElementClass *) klass;
GstBaseSinkClass *basesink_class = (GstBaseSinkClass *) klass;
GST_DEBUG_CATEGORY_INIT (app_sink_debug, "appsink", 0, "appsink element");
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-sample 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 emitted the signal
*
* Signal that the end-of-stream has been reached. This signal is emitted 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 emitted the signal
*
* Signal that a new preroll sample is available.
*
* This signal is emitted from the steaming thread and only when the
* "emit-signals" property is %TRUE.
*
* The new preroll sample 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 emitted 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, __gst_app_marshal_ENUM__VOID, GST_TYPE_FLOW_RETURN, 0,
G_TYPE_NONE);
/**
* GstAppSink::new-sample:
* @appsink: the appsink element that emited the signal
*
* Signal that a new sample is available.
*
* This signal is emitted from the steaming thread and only when the
* "emit-signals" property is %TRUE.
*
* The new sample can be retrieved with the "pull-sample" action
* signal or gst_app_sink_pull_sample() either from this signal callback
* or from any other thread.
*
* Note that this signal is only emitted when the "emit-signals" property is
* set to %TRUE, which it is not by default for performance reasons.
*/
gst_app_sink_signals[SIGNAL_NEW_SAMPLE] =
g_signal_new ("new-sample", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GstAppSinkClass, new_sample),
NULL, NULL, __gst_app_marshal_ENUM__VOID, GST_TYPE_FLOW_RETURN, 0,
G_TYPE_NONE);
/**
* GstAppSink::pull-preroll:
* @appsink: the appsink element to emit this signal on
*
* Get the last preroll sample in @appsink. This was the sample that caused the
* appsink to preroll in the PAUSED state. This sample 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 sample right
* after the seek position.
*
* Note that the preroll sample will also be returned as the first sample
* when calling gst_app_sink_pull_sample() or the "pull-sample" 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 sample or EOS is received or the appsink
* element is set to the READY/NULL state.
*
* Returns: a #GstSample 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_BOXED__VOID,
GST_TYPE_SAMPLE, 0, G_TYPE_NONE);
/**
* GstAppSink::pull-sample:
* @appsink: the appsink element to emit this signal on
*
* This function blocks until a sample or EOS becomes available or the appsink
* element is set to the READY/NULL state.
*
* This function will only return samples when the appsink is in the PLAYING
* state. All rendered samples will be put in a queue so that the application
* can pull samples at its own rate.
*
* Note that when the application does not pull samples fast enough, the
* queued samples 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 #GstSample or NULL when the appsink is stopped or EOS.
*/
gst_app_sink_signals[SIGNAL_PULL_SAMPLE] =
g_signal_new ("pull-sample", G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION, G_STRUCT_OFFSET (GstAppSinkClass,
pull_sample), NULL, NULL, __gst_app_marshal_BOXED__VOID,
GST_TYPE_SAMPLE, 0, G_TYPE_NONE);
gst_element_class_set_static_metadata (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));
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->get_caps = gst_app_sink_getcaps;
basesink_class->set_caps = gst_app_sink_setcaps;
basesink_class->query = gst_app_sink_query;
klass->pull_preroll = gst_app_sink_pull_preroll;
klass->pull_sample = gst_app_sink_pull_sample;
g_type_class_add_private (klass, sizeof (GstAppSinkPrivate));
}
static void
gst_app_sink_init (GstAppSink * appsink)
{
GstAppSinkPrivate *priv;
priv = appsink->priv =
G_TYPE_INSTANCE_GET_PRIVATE (appsink, GST_TYPE_APP_SINK,
GstAppSinkPrivate);
g_mutex_init (&priv->mutex);
g_cond_init (&priv->cond);
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);
while ((queue_obj = g_queue_pop_head (priv->queue)))
gst_mini_object_unref (queue_obj);
gst_buffer_replace (&priv->preroll, NULL);
gst_caps_replace (&priv->preroll_caps, NULL);
gst_caps_replace (&priv->last_caps, NULL);
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_clear (&priv->mutex);
g_cond_clear (&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);
priv->num_buffers = 0;
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->flushing = FALSE;
priv->started = TRUE;
gst_segment_init (&priv->last_segment, GST_FORMAT_TIME);
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);
gst_caps_replace (&priv->preroll_caps, NULL);
gst_caps_replace (&priv->last_caps, NULL);
g_mutex_unlock (&priv->mutex);
return TRUE;
}
static gboolean
gst_app_sink_setcaps (GstBaseSink * sink, GstCaps * caps)
{
GstAppSink *appsink = GST_APP_SINK_CAST (sink);
GstAppSinkPrivate *priv = appsink->priv;
g_mutex_lock (&priv->mutex);
GST_DEBUG_OBJECT (appsink, "receiving CAPS");
g_queue_push_tail (priv->queue, gst_event_new_caps (caps));
gst_caps_replace (&priv->preroll_caps, caps);
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_SEGMENT:
g_mutex_lock (&priv->mutex);
GST_DEBUG_OBJECT (appsink, "receiving SEGMENT");
g_queue_push_tail (priv->queue, gst_event_ref (event));
g_mutex_unlock (&priv->mutex);
break;
case GST_EVENT_EOS:{
gboolean emit = TRUE;
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);
g_mutex_lock (&priv->mutex);
/* wait until all buffers are consumed or we're flushing.
* Otherwise we might signal EOS before all buffers are
* consumed, which is a bit confusing for the application
*/
while (priv->num_buffers > 0 && !priv->flushing)
g_cond_wait (&priv->cond, &priv->mutex);
if (priv->flushing)
emit = FALSE;
g_mutex_unlock (&priv->mutex);
if (emit) {
/* 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 GST_BASE_SINK_CLASS (parent_class)->event (sink, event);
}
static GstFlowReturn
gst_app_sink_preroll (GstBaseSink * psink, GstBuffer * buffer)
{
GstFlowReturn res;
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 {
res = GST_FLOW_OK;
if (emit)
g_signal_emit (appsink, gst_app_sink_signals[SIGNAL_NEW_PREROLL], 0,
&res);
}
return res;
flushing:
{
GST_DEBUG_OBJECT (appsink, "we are flushing");
g_mutex_unlock (&priv->mutex);
return GST_FLOW_FLUSHING;
}
}
static GstBuffer *
dequeue_buffer (GstAppSink * appsink)
{
GstAppSinkPrivate *priv = appsink->priv;
GstBuffer *buffer;
do {
GstMiniObject *obj;
obj = g_queue_pop_head (priv->queue);
if (GST_IS_BUFFER (obj)) {
buffer = GST_BUFFER_CAST (obj);
GST_DEBUG_OBJECT (appsink, "dequeued buffer %p", buffer);
priv->num_buffers--;
break;
} else if (GST_IS_EVENT (obj)) {
GstEvent *event = GST_EVENT_CAST (obj);
switch (GST_EVENT_TYPE (obj)) {
case GST_EVENT_CAPS:
{
GstCaps *caps;
gst_event_parse_caps (event, &caps);
GST_DEBUG_OBJECT (appsink, "activating caps %" GST_PTR_FORMAT, caps);
gst_caps_replace (&priv->last_caps, caps);
break;
}
case GST_EVENT_SEGMENT:
gst_event_copy_segment (event, &priv->last_segment);
GST_DEBUG_OBJECT (appsink, "activated segment %" GST_SEGMENT_FORMAT,
&priv->last_segment);
break;
default:
break;
}
gst_mini_object_unref (obj);
}
} while (TRUE);
return buffer;
}
static GstFlowReturn
gst_app_sink_render (GstBaseSink * psink, GstBuffer * buffer)
{
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;
/* queue holding caps event might have been FLUSHed,
* but caps state still present in pad caps */
if (G_UNLIKELY (!priv->last_caps &&
gst_pad_has_current_caps (GST_BASE_SINK_PAD (psink)))) {
priv->last_caps = gst_pad_get_current_caps (GST_BASE_SINK_PAD (psink));
GST_DEBUG_OBJECT (appsink, "activating pad caps %" GST_PTR_FORMAT,
priv->last_caps);
}
GST_DEBUG_OBJECT (appsink, "pushing render buffer %p on queue (%d)",
buffer, priv->num_buffers);
while (priv->max_buffers > 0 && priv->num_buffers >= priv->max_buffers) {
if (priv->drop) {
GstBuffer *old;
/* we need to drop the oldest buffer and try again */
if ((old = dequeue_buffer (appsink))) {
GST_DEBUG_OBJECT (appsink, "dropping old buffer %p", old);
gst_buffer_unref (old);
}
} else {
GST_DEBUG_OBJECT (appsink, "waiting for free space, length %d >= %d",
priv->num_buffers, 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_buffer_ref (buffer));
priv->num_buffers++;
g_cond_signal (&priv->cond);
emit = priv->emit_signals;
g_mutex_unlock (&priv->mutex);
if (priv->callbacks.new_sample) {
ret = priv->callbacks.new_sample (appsink, priv->user_data);
} else {
ret = GST_FLOW_OK;
if (emit)
g_signal_emit (appsink, gst_app_sink_signals[SIGNAL_NEW_SAMPLE], 0, &ret);
}
return ret;
flushing:
{
GST_DEBUG_OBJECT (appsink, "we are flushing");
g_mutex_unlock (&priv->mutex);
return GST_FLOW_FLUSHING;
}
stopping:
{
GST_DEBUG_OBJECT (appsink, "we are stopping");
return ret;
}
}
static GstCaps *
gst_app_sink_getcaps (GstBaseSink * psink, GstCaps * filter)
{
GstCaps *caps;
GstAppSink *appsink = GST_APP_SINK_CAST (psink);
GstAppSinkPrivate *priv = appsink->priv;
GST_OBJECT_LOCK (appsink);
if ((caps = priv->caps)) {
if (filter)
caps = gst_caps_intersect_full (filter, caps, GST_CAPS_INTERSECT_FIRST);
else
gst_caps_ref (caps);
}
GST_DEBUG_OBJECT (appsink, "got caps %" GST_PTR_FORMAT, caps);
GST_OBJECT_UNLOCK (appsink);
return caps;
}
static gboolean
gst_app_sink_query (GstBaseSink * bsink, GstQuery * query)
{
gboolean ret;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_SEEKING:{
GstFormat fmt;
/* we don't supporting seeking */
gst_query_parse_seeking (query, &fmt, NULL, NULL, NULL);
gst_query_set_seeking (query, fmt, FALSE, 0, -1);
ret = TRUE;
break;
}
default:
ret = GST_BASE_SINK_CLASS (parent_class)->query (bsink, query);
break;
}
return ret;
}
/* 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.
*/
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.
*/
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 samples 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 samples can be pulled and the appsink is EOS.
*/
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 && priv->num_buffers == 0) {
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-sample" signals. This option is
* by default disabled because signal emission is expensive and unneeded when
* the application prefers to operate in pull mode.
*/
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-sample" signals.
*
* Returns: %TRUE if @appsink is emiting the "new-preroll" and "new-sample"
* signals.
*/
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 sample is pulled from @appsink.
*/
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.
*/
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.
*/
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.
*/
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 sample in @appsink. This was the sample that caused the
* appsink to preroll in the PAUSED state. This sample 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 sample right
* after the seek position.
*
* Note that the preroll sample will also be returned as the first sample
* when calling gst_app_sink_pull_sample().
*
* 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 sample or EOS is received or the appsink
* element is set to the READY/NULL state.
*
* Returns: (transfer full): a #GstSample or NULL when the appsink is stopped or EOS.
* Call gst_sample_unref() after usage.
*/
GstSample *
gst_app_sink_pull_preroll (GstAppSink * appsink)
{
GstSample *sample = 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);
}
sample =
gst_sample_new (priv->preroll, priv->preroll_caps, &priv->last_segment,
NULL);
GST_DEBUG_OBJECT (appsink, "we have the preroll sample %p", sample);
g_mutex_unlock (&priv->mutex);
return sample;
/* 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_sample:
* @appsink: a #GstAppSink
*
* This function blocks until a sample or EOS becomes available or the appsink
* element is set to the READY/NULL state.
*
* This function will only return samples when the appsink is in the PLAYING
* state. All rendered buffers will be put in a queue so that the application
* can pull samples at its own rate. Note that when the application does not
* pull samples 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: (transfer full): a #GstSample or NULL when the appsink is stopped or EOS.
* Call gst_sample_unref() after usage.
*/
GstSample *
gst_app_sink_pull_sample (GstAppSink * appsink)
{
GstSample *sample = NULL;
GstBuffer *buffer;
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->num_buffers > 0)
break;
if (priv->is_eos)
goto eos;
/* nothing to return, wait */
GST_DEBUG_OBJECT (appsink, "waiting for a buffer");
g_cond_wait (&priv->cond, &priv->mutex);
}
buffer = dequeue_buffer (appsink);
GST_DEBUG_OBJECT (appsink, "we have a buffer %p", buffer);
sample = gst_sample_new (buffer, priv->last_caps, &priv->last_segment, NULL);
gst_buffer_unref (buffer);
g_cond_signal (&priv->cond);
g_mutex_unlock (&priv->mutex);
return sample;
/* 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_set_callbacks: (skip)
* @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 sample 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 emitted for performance
* reasons.
*/
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 (GType type)
{
return GST_URI_SINK;
}
static const gchar *const *
gst_app_sink_uri_get_protocols (GType type)
{
static const gchar *protocols[] = { "appsink", NULL };
return protocols;
}
static gchar *
gst_app_sink_uri_get_uri (GstURIHandler * handler)
{
return g_strdup ("appsink");
}
static gboolean
gst_app_sink_uri_set_uri (GstURIHandler * handler, const gchar * uri,
GError ** error)
{
/* GstURIHandler checks the protocol for us */
return TRUE;
}
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;
}