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__
28 /**************************
29 * GstAggregator Structs *
30 *************************/
32 typedef struct _GstAggregator GstAggregator;
33 typedef struct _GstAggregatorPrivate GstAggregatorPrivate;
34 typedef struct _GstAggregatorClass GstAggregatorClass;
36 /************************
37 * GstAggregatorPad API *
38 ***********************/
40 #define GST_TYPE_AGGREGATOR_PAD (gst_aggregator_pad_get_type())
41 #define GST_AGGREGATOR_PAD(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPad))
42 #define GST_AGGREGATOR_PAD_CAST(obj) ((GstAggregatorPad *)(obj))
43 #define GST_AGGREGATOR_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPadClass))
44 #define GST_AGGREGATOR_PAD_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPadClass))
45 #define GST_IS_AGGREGATOR_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AGGREGATOR_PAD))
46 #define GST_IS_AGGREGATOR_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AGGREGATOR_PAD))
48 /****************************
49 * GstAggregatorPad Structs *
50 ***************************/
52 typedef struct _GstAggregatorPad GstAggregatorPad;
53 typedef struct _GstAggregatorPadClass GstAggregatorPadClass;
54 typedef struct _GstAggregatorPadPrivate GstAggregatorPadPrivate;
58 * @segment: last segment received.
60 * The implementation the GstPad to use with #GstAggregator
62 struct _GstAggregatorPad
66 /* Protected by the OBJECT_LOCK */
70 GstAggregatorPadPrivate * priv;
72 gpointer _gst_reserved[GST_PADDING];
76 * GstAggregatorPadClass:
78 * Called when the pad has received a flush stop, this is the place
79 * to flush any information specific to the pad, it allows for individual
80 * pads to be flushed while others might not be.
83 struct _GstAggregatorPadClass
85 GstPadClass parent_class;
87 GstFlowReturn (*flush) (GstAggregatorPad * aggpad, GstAggregator * aggregator);
90 gpointer _gst_reserved[GST_PADDING_LARGE];
94 GType gst_aggregator_pad_get_type (void);
96 /****************************
97 * GstAggregatorPad methods *
98 ***************************/
101 GstBuffer * gst_aggregator_pad_steal_buffer (GstAggregatorPad * pad);
104 GstBuffer * gst_aggregator_pad_get_buffer (GstAggregatorPad * pad);
107 gboolean gst_aggregator_pad_drop_buffer (GstAggregatorPad * pad);
110 gboolean gst_aggregator_pad_is_eos (GstAggregatorPad * pad);
112 /*********************
113 * GstAggregator API *
114 ********************/
116 #define GST_TYPE_AGGREGATOR (gst_aggregator_get_type())
117 #define GST_AGGREGATOR(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AGGREGATOR,GstAggregator))
118 #define GST_AGGREGATOR_CAST(obj) ((GstAggregator *)(obj))
119 #define GST_AGGREGATOR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AGGREGATOR,GstAggregatorClass))
120 #define GST_AGGREGATOR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_AGGREGATOR,GstAggregatorClass))
121 #define GST_IS_AGGREGATOR(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AGGREGATOR))
122 #define GST_IS_AGGREGATOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AGGREGATOR))
124 #define GST_AGGREGATOR_FLOW_NEED_DATA GST_FLOW_CUSTOM_ERROR
128 * @srcpad: the aggregator's source pad
129 * @segment: the output segment
131 * Aggregator base class object structure.
133 struct _GstAggregator
139 /* Only access with the object lock held */
143 GstAggregatorPrivate * priv;
145 gpointer _gst_reserved[GST_PADDING_LARGE];
149 * GstAggregatorClass:
151 * Called after a successful flushing seek, once all the flush
152 * stops have been received. Flush pad-specific data in
153 * #GstAggregatorPad->flush.
155 * Called when a buffer is received on a sink pad, the task of
156 * clipping it and translating it to the current segment falls
157 * on the subclass. The function should use the segment of data
158 * and the negotiated media type on the pad to perform
159 * clipping of input buffer. This function takes ownership of
160 * buf and should output a buffer or return NULL in
161 * if the buffer should be dropped.
162 * @finish_buffer: Optional.
163 * Called when a subclass calls gst_aggregator_finish_buffer()
164 * from their aggregate function to push out a buffer.
165 * Subclasses can override this to modify or decorate buffers
166 * before they get pushed out. This function takes ownership
167 * of the buffer passed. Subclasses that override this method
168 * should always chain up to the parent class virtual method.
169 * @sink_event: Optional.
170 * Called when an event is received on a sink pad, the subclass
171 * should always chain up.
172 * @sink_query: Optional.
173 * Called when a query is received on a sink pad, the subclass
174 * should always chain up.
175 * @src_event: Optional.
176 * Called when an event is received on the src pad, the subclass
177 * should always chain up.
178 * @src_query: Optional.
179 * Called when a query is received on the src pad, the subclass
180 * should always chain up.
181 * @src_activate: Optional.
182 * Called when the src pad is activated, it will start/stop its
183 * pad task right after that call.
184 * @aggregate: Mandatory.
185 * Called when buffers are queued on all sinkpads. Classes
186 * should iterate the GstElement->sinkpads and peek or steal
187 * buffers from the #GstAggregatorPads. If the subclass returns
188 * GST_FLOW_EOS, sending of the eos event will be taken care
189 * of. Once / if a buffer has been constructed from the
190 * aggregated buffers, the subclass should call _finish_buffer.
192 * Called when the element goes from PAUSED to READY.
193 * The subclass should free all resources and reset its state.
195 * Called when the element goes from READY to PAUSED.
196 * The subclass should get ready to process
197 * aggregated buffers.
198 * @get_next_time: Optional.
199 * Called when the element needs to know the running time of the next
200 * rendered buffer for live pipelines. This causes deadline
201 * based aggregation to occur. Defaults to returning
202 * GST_CLOCK_TIME_NONE causing the element to wait for buffers
203 * on all sink pads before aggregating.
204 * @update_src_caps: Lets subclasses update the #GstCaps representing
205 * the src pad caps before usage. The result should end up
206 * in @ret. Return %GST_AGGREGATOR_FLOW_NEED_DATA to indicate that the
207 * element needs more information (caps, a buffer, etc) to
208 * choose the correct caps. Should return ANY caps if the
209 * stream has not caps at all.
210 * @fixate_src_caps: Optional.
211 * Fixate and return the src pad caps provided. The function takes
212 * ownership of @caps and returns a fixated version of
213 * @caps. @caps is not guaranteed to be writable.
214 * @negotiated_src_caps: Optional.
215 * Notifies subclasses what caps format has been negotiated
216 * @decide_allocation: Optional.
217 * Allows the subclass to influence the allocation choices.
218 * Setup the allocation parameters for allocating output
219 * buffers. The passed in query contains the result of the
220 * downstream allocation query.
222 * The aggregator base class will handle in a thread-safe way all manners of
223 * concurrent flushes, seeks, pad additions and removals, leaving to the
224 * subclass the responsibility of clipping buffers, and aggregating buffers in
225 * the way the implementor sees fit.
227 * It will also take care of event ordering (stream-start, segment, eos).
229 * Basically, a simple implementation will override @aggregate, and call
230 * _finish_buffer from inside that function.
232 struct _GstAggregatorClass {
233 GstElementClass parent_class;
235 GstFlowReturn (*flush) (GstAggregator * aggregator);
237 GstBuffer * (*clip) (GstAggregator * aggregator,
238 GstAggregatorPad * aggregator_pad,
241 GstFlowReturn (*finish_buffer) (GstAggregator * aggregator,
244 /* sinkpads virtual methods */
245 gboolean (*sink_event) (GstAggregator * aggregator,
246 GstAggregatorPad * aggregator_pad,
249 gboolean (*sink_query) (GstAggregator * aggregator,
250 GstAggregatorPad * aggregator_pad,
253 /* srcpad virtual methods */
254 gboolean (*src_event) (GstAggregator * aggregator,
257 gboolean (*src_query) (GstAggregator * aggregator,
260 gboolean (*src_activate) (GstAggregator * aggregator,
264 GstFlowReturn (*aggregate) (GstAggregator * aggregator,
267 gboolean (*stop) (GstAggregator * aggregator);
269 gboolean (*start) (GstAggregator * aggregator);
271 GstClockTime (*get_next_time) (GstAggregator * aggregator);
273 GstAggregatorPad * (*create_new_pad) (GstAggregator * self,
274 GstPadTemplate * templ,
275 const gchar * req_name,
276 const GstCaps * caps);
277 GstFlowReturn (*update_src_caps) (GstAggregator * self,
280 GstCaps * (*fixate_src_caps) (GstAggregator * self,
282 gboolean (*negotiated_src_caps) (GstAggregator * self,
284 gboolean (*decide_allocation) (GstAggregator * self,
286 gboolean (*propose_allocation) (GstAggregator * self,
287 GstAggregatorPad * pad,
288 GstQuery * decide_query,
291 gpointer _gst_reserved[GST_PADDING_LARGE];
294 /************************************
295 * GstAggregator convenience macros *
296 ***********************************/
299 * GST_AGGREGATOR_SRC_PAD:
300 * @agg: a #GstAggregator
302 * Convenience macro to access the source pad of #GstAggregator
306 #define GST_AGGREGATOR_SRC_PAD(agg) (((GstAggregator *)(agg))->srcpad)
308 /*************************
309 * GstAggregator methods *
310 ************************/
313 GstFlowReturn gst_aggregator_finish_buffer (GstAggregator * aggregator,
317 void gst_aggregator_set_src_caps (GstAggregator * self,
321 void gst_aggregator_set_latency (GstAggregator * self,
322 GstClockTime min_latency,
323 GstClockTime max_latency);
326 GType gst_aggregator_get_type(void);
329 GstClockTime gst_aggregator_get_latency (GstAggregator * self);
332 GstBufferPool * gst_aggregator_get_buffer_pool (GstAggregator * self);
335 void gst_aggregator_get_allocator (GstAggregator * self,
336 GstAllocator ** allocator,
337 GstAllocationParams * params);
341 #endif /* __GST_AGGREGATOR_H__ */