/* GStreamer * Copyright (C) 2007 David Schleef * (C) 2008 Wim Taymans * * 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. * * Last reviewed on 2008-12-17 (0.10.22) */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #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, new-buffer and new-buffer-list 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 , Wim Taymans "); 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: 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 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: a #GstBuffer or NULL when the appsink is stopped or EOS. */ 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: a #GstBuffer or NULL when the appsink is stopped or EOS. */ 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; }