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__
25 #include <gst/base/base-prelude.h>
29 /**************************
30 * GstAggregator Structs *
31 *************************/
33 typedef struct _GstAggregator GstAggregator;
34 typedef struct _GstAggregatorPrivate GstAggregatorPrivate;
35 typedef struct _GstAggregatorClass GstAggregatorClass;
37 /************************
38 * GstAggregatorPad API *
39 ***********************/
41 #define GST_TYPE_AGGREGATOR_PAD (gst_aggregator_pad_get_type())
42 #define GST_AGGREGATOR_PAD(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPad))
43 #define GST_AGGREGATOR_PAD_CAST(obj) ((GstAggregatorPad *)(obj))
44 #define GST_AGGREGATOR_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPadClass))
45 #define GST_AGGREGATOR_PAD_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_AGGREGATOR_PAD, GstAggregatorPadClass))
46 #define GST_IS_AGGREGATOR_PAD(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AGGREGATOR_PAD))
47 #define GST_IS_AGGREGATOR_PAD_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AGGREGATOR_PAD))
49 /****************************
50 * GstAggregatorPad Structs *
51 ***************************/
53 typedef struct _GstAggregatorPad GstAggregatorPad;
54 typedef struct _GstAggregatorPadClass GstAggregatorPadClass;
55 typedef struct _GstAggregatorPadPrivate GstAggregatorPadPrivate;
59 * @segment: last segment received.
61 * The implementation the GstPad to use with #GstAggregator
63 struct _GstAggregatorPad
68 /* Protected by the OBJECT_LOCK */
72 GstAggregatorPadPrivate * priv;
74 gpointer _gst_reserved[GST_PADDING];
78 * GstAggregatorPadClass:
80 * Called when the pad has received a flush stop, this is the place
81 * to flush any information specific to the pad, it allows for individual
82 * pads to be flushed while others might not be.
83 * @skip_buffer: Optional
84 * Called before input buffers are queued in the pad, return %TRUE
85 * if the buffer should be skipped.
88 struct _GstAggregatorPadClass
90 GstPadClass parent_class;
92 GstFlowReturn (*flush) (GstAggregatorPad * aggpad, GstAggregator * aggregator);
93 gboolean (*skip_buffer) (GstAggregatorPad * aggpad, GstAggregator * aggregator, GstBuffer * buffer);
96 gpointer _gst_reserved[GST_PADDING_LARGE];
100 GType gst_aggregator_pad_get_type (void);
102 /****************************
103 * GstAggregatorPad methods *
104 ***************************/
107 GstBuffer * gst_aggregator_pad_pop_buffer (GstAggregatorPad * pad);
110 GstBuffer * gst_aggregator_pad_peek_buffer (GstAggregatorPad * pad);
113 gboolean gst_aggregator_pad_drop_buffer (GstAggregatorPad * pad);
116 gboolean gst_aggregator_pad_is_eos (GstAggregatorPad * pad);
118 /*********************
119 * GstAggregator API *
120 ********************/
122 #define GST_TYPE_AGGREGATOR (gst_aggregator_get_type())
123 #define GST_AGGREGATOR(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AGGREGATOR,GstAggregator))
124 #define GST_AGGREGATOR_CAST(obj) ((GstAggregator *)(obj))
125 #define GST_AGGREGATOR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_AGGREGATOR,GstAggregatorClass))
126 #define GST_AGGREGATOR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj),GST_TYPE_AGGREGATOR,GstAggregatorClass))
127 #define GST_IS_AGGREGATOR(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AGGREGATOR))
128 #define GST_IS_AGGREGATOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_AGGREGATOR))
130 #define GST_AGGREGATOR_FLOW_NEED_DATA GST_FLOW_CUSTOM_ERROR
134 * @srcpad: the aggregator's source pad
136 * Aggregator base class object structure.
138 struct _GstAggregator
146 GstAggregatorPrivate * priv;
148 gpointer _gst_reserved[GST_PADDING_LARGE];
152 * GstAggregatorClass:
154 * Called after a successful flushing seek, once all the flush
155 * stops have been received. Flush pad-specific data in
156 * #GstAggregatorPad->flush.
158 * Called when a buffer is received on a sink pad, the task of
159 * clipping it and translating it to the current segment falls
160 * on the subclass. The function should use the segment of data
161 * and the negotiated media type on the pad to perform
162 * clipping of input buffer. This function takes ownership of
163 * buf and should output a buffer or return NULL in
164 * if the buffer should be dropped.
165 * @finish_buffer: Optional.
166 * Called when a subclass calls gst_aggregator_finish_buffer()
167 * from their aggregate function to push out a buffer.
168 * Subclasses can override this to modify or decorate buffers
169 * before they get pushed out. This function takes ownership
170 * of the buffer passed. Subclasses that override this method
171 * should always chain up to the parent class virtual method.
172 * @sink_event: Optional.
173 * Called when an event is received on a sink pad, the subclass
174 * should always chain up.
175 * @sink_query: Optional.
176 * Called when a query is received on a sink pad, the subclass
177 * should always chain up.
178 * @src_event: Optional.
179 * Called when an event is received on the src pad, the subclass
180 * should always chain up.
181 * @src_query: Optional.
182 * Called when a query is received on the src pad, the subclass
183 * should always chain up.
184 * @src_activate: Optional.
185 * Called when the src pad is activated, it will start/stop its
186 * pad task right after that call.
187 * @aggregate: Mandatory.
188 * Called when buffers are queued on all sinkpads. Classes
189 * should iterate the GstElement->sinkpads and peek or steal
190 * buffers from the #GstAggregatorPads. If the subclass returns
191 * GST_FLOW_EOS, sending of the eos event will be taken care
192 * of. Once / if a buffer has been constructed from the
193 * aggregated buffers, the subclass should call _finish_buffer.
195 * Called when the element goes from PAUSED to READY.
196 * The subclass should free all resources and reset its state.
198 * Called when the element goes from READY to PAUSED.
199 * The subclass should get ready to process
200 * aggregated buffers.
201 * @get_next_time: Optional.
202 * Called when the element needs to know the running time of the next
203 * rendered buffer for live pipelines. This causes deadline
204 * based aggregation to occur. Defaults to returning
205 * GST_CLOCK_TIME_NONE causing the element to wait for buffers
206 * on all sink pads before aggregating.
207 * @create_new_pad: Optional.
208 * Called when a new pad needs to be created. Allows subclass that
209 * don't have a single sink pad template to provide a pad based
210 * on the provided information.
211 * @update_src_caps: Lets subclasses update the #GstCaps representing
212 * the src pad caps before usage. The result should end up
213 * in @ret. Return %GST_AGGREGATOR_FLOW_NEED_DATA to indicate that the
214 * element needs more information (caps, a buffer, etc) to
215 * choose the correct caps. Should return ANY caps if the
216 * stream has not caps at all.
217 * @fixate_src_caps: Optional.
218 * Fixate and return the src pad caps provided. The function takes
219 * ownership of @caps and returns a fixated version of
220 * @caps. @caps is not guaranteed to be writable.
221 * @negotiated_src_caps: Optional.
222 * Notifies subclasses what caps format has been negotiated
223 * @decide_allocation: Optional.
224 * Allows the subclass to influence the allocation choices.
225 * Setup the allocation parameters for allocating output
226 * buffers. The passed in query contains the result of the
227 * downstream allocation query.
228 * @propose_allocation: Optional.
229 * Allows the subclass to handle the allocation query from upstream.
231 * The aggregator base class will handle in a thread-safe way all manners of
232 * concurrent flushes, seeks, pad additions and removals, leaving to the
233 * subclass the responsibility of clipping buffers, and aggregating buffers in
234 * the way the implementor sees fit.
236 * It will also take care of event ordering (stream-start, segment, eos).
238 * Basically, a simple implementation will override @aggregate, and call
239 * _finish_buffer from inside that function.
241 struct _GstAggregatorClass {
242 GstElementClass parent_class;
244 GstFlowReturn (*flush) (GstAggregator * aggregator);
246 GstBuffer * (*clip) (GstAggregator * aggregator,
247 GstAggregatorPad * aggregator_pad,
250 GstFlowReturn (*finish_buffer) (GstAggregator * aggregator,
253 /* sinkpads virtual methods */
254 gboolean (*sink_event) (GstAggregator * aggregator,
255 GstAggregatorPad * aggregator_pad,
258 gboolean (*sink_query) (GstAggregator * aggregator,
259 GstAggregatorPad * aggregator_pad,
262 /* srcpad virtual methods */
263 gboolean (*src_event) (GstAggregator * aggregator,
266 gboolean (*src_query) (GstAggregator * aggregator,
269 gboolean (*src_activate) (GstAggregator * aggregator,
273 GstFlowReturn (*aggregate) (GstAggregator * aggregator,
276 gboolean (*stop) (GstAggregator * aggregator);
278 gboolean (*start) (GstAggregator * aggregator);
280 GstClockTime (*get_next_time) (GstAggregator * aggregator);
282 GstAggregatorPad * (*create_new_pad) (GstAggregator * self,
283 GstPadTemplate * templ,
284 const gchar * req_name,
285 const GstCaps * caps);
286 GstFlowReturn (*update_src_caps) (GstAggregator * self,
289 GstCaps * (*fixate_src_caps) (GstAggregator * self,
291 gboolean (*negotiated_src_caps) (GstAggregator * self,
293 gboolean (*decide_allocation) (GstAggregator * self,
295 gboolean (*propose_allocation) (GstAggregator * self,
296 GstAggregatorPad * pad,
297 GstQuery * decide_query,
300 gpointer _gst_reserved[GST_PADDING_LARGE];
303 /************************************
304 * GstAggregator convenience macros *
305 ***********************************/
308 * GST_AGGREGATOR_SRC_PAD:
309 * @agg: a #GstAggregator
311 * Convenience macro to access the source pad of #GstAggregator
315 #define GST_AGGREGATOR_SRC_PAD(agg) (((GstAggregator *)(agg))->srcpad)
317 /*************************
318 * GstAggregator methods *
319 ************************/
322 GstFlowReturn gst_aggregator_finish_buffer (GstAggregator * aggregator,
326 void gst_aggregator_set_src_caps (GstAggregator * self,
330 void gst_aggregator_set_latency (GstAggregator * self,
331 GstClockTime min_latency,
332 GstClockTime max_latency);
335 GType gst_aggregator_get_type(void);
338 GstClockTime gst_aggregator_get_latency (GstAggregator * self);
341 GstBufferPool * gst_aggregator_get_buffer_pool (GstAggregator * self);
344 void gst_aggregator_get_allocator (GstAggregator * self,
345 GstAllocator ** allocator,
346 GstAllocationParams * params);
350 #endif /* __GST_AGGREGATOR_H__ */