1 /* GStreamer aggregator base class
2 * Copyright (C) 2014 Mathieu Duponchelle <mathieu.duponchelle@oencreed.com>
3 * Copyright (C) 2014 Thibault Saunier <tsaunier@gnome.org>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
21 #ifndef __GST_AGGREGATOR_H__
22 #define __GST_AGGREGATOR_H__
24 #ifndef GST_USE_UNSTABLE_API
25 #warning "The Base library from gst-plugins-bad is unstable API and may change in future."
26 #warning "You can define GST_USE_UNSTABLE_API to avoid this warning."
33 /**************************
34 * GstAggregator Structs *
35 *************************/
37 typedef struct _GstAggregator GstAggregator;
38 typedef struct _GstAggregatorPrivate GstAggregatorPrivate;
39 typedef struct _GstAggregatorClass GstAggregatorClass;
41 /************************
42 * GstAggregatorPad API *
43 ***********************/
45 #define GST_TYPE_AGGREGATOR_PAD (gst_aggregator_pad_get_type())
46 #define GST_AGGREGATOR_PAD(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPad))
47 #define GST_AGGREGATOR_PAD_CAST(obj) ((GstAggregatorPad *)(obj))
48 #define GST_AGGREGATOR_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPadClass))
49 #define GST_AGGREGATOR_PAD_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPadClass))
50 #define GST_IS_AGGREGATOR_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AGGREGATOR_PAD))
51 #define GST_IS_AGGREGATOR_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AGGREGATOR_PAD))
53 /****************************
54 * GstAggregatorPad Structs *
55 ***************************/
57 typedef struct _GstAggregatorPad GstAggregatorPad;
58 typedef struct _GstAggregatorPadClass GstAggregatorPadClass;
59 typedef struct _GstAggregatorPadPrivate GstAggregatorPadPrivate;
63 * @buffer: currently queued buffer.
64 * @segment: last segment received.
66 * The implementation the GstPad to use with #GstAggregator
68 struct _GstAggregatorPad
72 /* Protected by the OBJECT_LOCK */
76 GstAggregatorPadPrivate * priv;
78 gpointer _gst_reserved[GST_PADDING];
82 * GstAggregatorPadClass:
84 * Called when the pad has received a flush stop, this is the place
85 * to flush any information specific to the pad, it allows for individual
86 * pads to be flushed while others might not be.
89 struct _GstAggregatorPadClass
91 GstPadClass parent_class;
93 GstFlowReturn (*flush) (GstAggregatorPad * aggpad, GstAggregator * aggregator);
96 gpointer _gst_reserved[GST_PADDING_LARGE];
99 GType gst_aggregator_pad_get_type (void);
101 /****************************
102 * GstAggregatorPad methods *
103 ***************************/
105 GstBuffer * gst_aggregator_pad_steal_buffer (GstAggregatorPad * pad);
106 GstBuffer * gst_aggregator_pad_get_buffer (GstAggregatorPad * pad);
107 gboolean gst_aggregator_pad_drop_buffer (GstAggregatorPad * pad);
108 gboolean gst_aggregator_pad_is_eos (GstAggregatorPad * pad);
110 /*********************
111 * GstAggregator API *
112 ********************/
114 #define GST_TYPE_AGGREGATOR (gst_aggregator_get_type())
115 #define GST_AGGREGATOR(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AGGREGATOR,GstAggregator))
116 #define GST_AGGREGATOR_CAST(obj) ((GstAggregator *)(obj))
117 #define GST_AGGREGATOR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AGGREGATOR,GstAggregatorClass))
118 #define GST_AGGREGATOR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_AGGREGATOR,GstAggregatorClass))
119 #define GST_IS_AGGREGATOR(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AGGREGATOR))
120 #define GST_IS_AGGREGATOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AGGREGATOR))
122 #define GST_AGGREGATOR_FLOW_NEED_DATA GST_FLOW_CUSTOM_ERROR
126 * @srcpad: the aggregator's source pad
127 * @segment: the output segment
129 * Aggregator base class object structure.
131 struct _GstAggregator
137 /* Only access with the object lock held */
141 GstAggregatorPrivate * priv;
143 gpointer _gst_reserved[GST_PADDING_LARGE];
147 * GstAggregatorClass:
148 * @sinkpads_type: Optional.
149 * The type of the pads that should be created when
150 * GstElement.request_new_pad is called.
152 * Called after a succesful flushing seek, once all the flush
153 * stops have been received. Flush pad-specific data in
154 * #GstAggregatorPad->flush.
156 * Called when a buffer is received on a sink pad, the task of
157 * clipping it and translating it to the current segment falls
158 * on the subclass. The function should use the segment of data
159 * and the negotiated media type on the pad to perform
160 * clipping of inbuffer. This function takes ownership of
161 * buf and should output a buffer or return NULL in
162 * if the buffer should be dropped.
163 * @sink_event: Optional.
164 * Called when an event is received on a sink pad, the subclass
165 * should always chain up.
166 * @sink_query: Optional.
167 * Called when a query is received on a sink pad, the subclass
168 * should always chain up.
169 * @src_event: Optional.
170 * Called when an event is received on the src pad, the subclass
171 * should always chain up.
172 * @src_query: Optional.
173 * Called when a query is received on the src pad, the subclass
174 * should always chain up.
175 * @src_activate: Optional.
176 * Called when the src pad is activated, it will start/stop its
177 * pad task right after that call.
178 * @aggregate: Mandatory.
179 * Called when buffers are queued on all sinkpads. Classes
180 * should iterate the GstElement->sinkpads and peek or steal
181 * buffers from the #GstAggregatorPads. If the subclass returns
182 * GST_FLOW_EOS, sending of the eos event will be taken care
183 * of. Once / if a buffer has been constructed from the
184 * aggregated buffers, the subclass should call _finish_buffer.
186 * Called when the element goes from PAUSED to READY.
187 * The subclass should free all resources and reset its state.
189 * Called when the element goes from READY to PAUSED.
190 * The subclass should get ready to process
191 * aggregated buffers.
192 * @get_next_time: Optional.
193 * Called when the element needs to know the running time of the next
194 * rendered buffer for live pipelines. This causes deadline
195 * based aggregation to occur. Defaults to returning
196 * GST_CLOCK_TIME_NONE causing the element to wait for buffers
197 * on all sink pads before aggregating.
198 * @update_src_caps: Lets subclasses update the #GstCaps representing
199 * the src pad caps before usage. The result should end up
200 * in @ret. Return %GST_AGGREGATOR_FLOW_NEED_DATA to indicate that the
201 * element needs more information (caps, a buffer, etc) to
202 * choose the correct caps. Should return ANY caps if the
203 * stream has not caps at all.
204 * @fixate_src_caps: Optional.
205 * Fixate and return the src pad caps provided. The function takes
206 * ownership of @caps and returns a fixated version of
207 * @caps. @caps is not guaranteed to be writable.
208 * @negotiated_src_caps: Optional.
209 * Notifies subclasses what caps format has been negotiated
210 * @decide_allocation: Optional.
211 * Allows the subclass to influence the allocation choices.
212 * Setup the allocation parameters for allocating output
213 * buffers. The passed in query contains the result of the
214 * downstream allocation query.
216 * The aggregator base class will handle in a thread-safe way all manners of
217 * concurrent flushes, seeks, pad additions and removals, leaving to the
218 * subclass the responsibility of clipping buffers, and aggregating buffers in
219 * the way the implementor sees fit.
221 * It will also take care of event ordering (stream-start, segment, eos).
223 * Basically, a basic implementation will override @aggregate, and call
224 * _finish_buffer from inside that function.
226 struct _GstAggregatorClass {
227 GstElementClass parent_class;
231 GstFlowReturn (*flush) (GstAggregator * aggregator);
233 GstBuffer * (*clip) (GstAggregator * aggregator,
234 GstAggregatorPad * aggregator_pad,
237 /* sinkpads virtual methods */
238 gboolean (*sink_event) (GstAggregator * aggregator,
239 GstAggregatorPad * aggregator_pad,
242 gboolean (*sink_query) (GstAggregator * aggregator,
243 GstAggregatorPad * aggregator_pad,
246 /* srcpad virtual methods */
247 gboolean (*src_event) (GstAggregator * aggregator,
250 gboolean (*src_query) (GstAggregator * aggregator,
253 gboolean (*src_activate) (GstAggregator * aggregator,
257 GstFlowReturn (*aggregate) (GstAggregator * aggregator,
260 gboolean (*stop) (GstAggregator * aggregator);
262 gboolean (*start) (GstAggregator * aggregator);
264 GstClockTime (*get_next_time) (GstAggregator * aggregator);
266 GstAggregatorPad * (*create_new_pad) (GstAggregator * self,
267 GstPadTemplate * templ,
268 const gchar * req_name,
269 const GstCaps * caps);
270 GstFlowReturn (*update_src_caps) (GstAggregator * self,
273 GstCaps * (*fixate_src_caps) (GstAggregator * self,
275 gboolean (*negotiated_src_caps) (GstAggregator * self,
277 gboolean (*decide_allocation) (GstAggregator * self,
279 gboolean (*propose_allocation) (GstAggregator * self,
280 GstAggregatorPad * pad,
281 GstQuery * decide_query,
284 gpointer _gst_reserved[GST_PADDING_LARGE];
287 /************************************
288 * GstAggregator convenience macros *
289 ***********************************/
292 * GST_AGGREGATOR_SRC_PAD:
293 * @agg: a #GstAggregator
295 * Convenience macro to access the source pad of #GstAggregator
299 #define GST_AGGREGATOR_SRC_PAD(agg) (((GstAggregator *)(agg))->srcpad)
301 /*************************
302 * GstAggregator methods *
303 ************************/
305 GstFlowReturn gst_aggregator_finish_buffer (GstAggregator * self,
307 void gst_aggregator_set_src_caps (GstAggregator * self,
310 void gst_aggregator_set_latency (GstAggregator * self,
311 GstClockTime min_latency,
312 GstClockTime max_latency);
314 GType gst_aggregator_get_type(void);
316 /* API that should eventually land in GstElement itself (FIXME) */
317 typedef gboolean (*GstAggregatorPadForeachFunc) (GstAggregator * aggregator,
318 GstAggregatorPad * aggregator_pad,
321 gboolean gst_aggregator_iterate_sinkpads (GstAggregator * self,
322 GstAggregatorPadForeachFunc func,
325 GstClockTime gst_aggregator_get_latency (GstAggregator * self);
327 GstBufferPool * gst_aggregator_get_buffer_pool (GstAggregator * self);
328 void gst_aggregator_get_allocator (GstAggregator * self,
337 #endif /* __GST_AGGREGATOR_H__ */