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1 /* GStreamer
2  * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3  *                    2000 Wim Taymans <wtay@chello.be>
4  *                    2005 Wim Taymans <wim@fluendo.com>
5  *
6  * gstbasesrc.h:
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Library General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Library General Public License for more details.
17  *
18  * You should have received a copy of the GNU Library General Public
19  * License along with this library; if not, write to the
20  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21  * Boston, MA 02110-1301, USA.
22  */
23 
24 #ifndef __GST_BASE_SRC_H__
25 #define __GST_BASE_SRC_H__
26 
27 #include <gst/gst.h>
28 #include <gst/base/base-prelude.h>
29 
30 G_BEGIN_DECLS
31 
32 #define GST_TYPE_BASE_SRC               (gst_base_src_get_type())
33 #define GST_BASE_SRC(obj)               (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BASE_SRC,GstBaseSrc))
34 #define GST_BASE_SRC_CLASS(klass)       (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BASE_SRC,GstBaseSrcClass))
35 #define GST_BASE_SRC_GET_CLASS(obj)     (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BASE_SRC, GstBaseSrcClass))
36 #define GST_IS_BASE_SRC(obj)            (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BASE_SRC))
37 #define GST_IS_BASE_SRC_CLASS(klass)    (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BASE_SRC))
38 #define GST_BASE_SRC_CAST(obj)          ((GstBaseSrc *)(obj))
39 
40 /**
41  * GstBaseSrcFlags:
42  * @GST_BASE_SRC_FLAG_STARTING: has source is starting
43  * @GST_BASE_SRC_FLAG_STARTED: has source been started
44  * @GST_BASE_SRC_FLAG_LAST: offset to define more flags
45  *
46  * The #GstElement flags that a basesrc element may have.
47  */
48 typedef enum {
49   GST_BASE_SRC_FLAG_STARTING     = (GST_ELEMENT_FLAG_LAST << 0),
50   GST_BASE_SRC_FLAG_STARTED      = (GST_ELEMENT_FLAG_LAST << 1),
51   /* padding */
52   GST_BASE_SRC_FLAG_LAST         = (GST_ELEMENT_FLAG_LAST << 6)
53 } GstBaseSrcFlags;
54 
55 #define GST_BASE_SRC_IS_STARTING(obj) GST_OBJECT_FLAG_IS_SET ((obj), GST_BASE_SRC_FLAG_STARTING)
56 #define GST_BASE_SRC_IS_STARTED(obj)  GST_OBJECT_FLAG_IS_SET ((obj), GST_BASE_SRC_FLAG_STARTED)
57 
58 typedef struct _GstBaseSrc GstBaseSrc;
59 typedef struct _GstBaseSrcClass GstBaseSrcClass;
60 typedef struct _GstBaseSrcPrivate GstBaseSrcPrivate;
61 
62 /**
63  * GST_BASE_SRC_PAD:
64  * @obj: base source instance
65  *
66  * Gives the pointer to the #GstPad object of the element.
67  */
68 #define GST_BASE_SRC_PAD(obj)                 (GST_BASE_SRC_CAST (obj)->srcpad)
69 
70 
71 /**
72  * GstBaseSrc:
73  *
74  * The opaque #GstBaseSrc data structure.
75  */
76 struct _GstBaseSrc {
77   GstElement     element;
78 
79   /*< protected >*/
80   GstPad        *srcpad;
81 
82   /* available to subclass implementations */
83   /* MT-protected (with LIVE_LOCK) */
84   GMutex         live_lock;
85   GCond          live_cond;
86   gboolean       is_live;
87   gboolean       live_running;
88 
89   /* MT-protected (with LOCK) */
90   guint          blocksize;     /* size of buffers when operating push based */
91   gboolean       can_activate_push;     /* some scheduling properties */
92   gboolean       random_access;
93 
94   GstClockID     clock_id;      /* for syncing */
95 
96   /* MT-protected (with STREAM_LOCK *and* OBJECT_LOCK) */
97   GstSegment     segment;
98   /* MT-protected (with STREAM_LOCK) */
99   gboolean       need_newsegment;
100 
101   gint           num_buffers;
102   gint           num_buffers_left;
103 
104 #ifndef GST_REMOVE_DEPRECATED
105   gboolean       typefind;      /* unused */
106 #endif
107 
108   gboolean       running;
109   GstEvent      *pending_seek;
110 
111   GstBaseSrcPrivate *priv;
112 
113   /*< private >*/
114   gpointer       _gst_reserved[GST_PADDING_LARGE];
115 };
116 
117 /**
118  * GstBaseSrcClass:
119  * @parent_class: Element parent class
120  * @get_caps: Called to get the caps to report
121  * @negotiate: Negotiated the caps with the peer.
122  * @fixate: Called during negotiation if caps need fixating. Implement instead of
123  *   setting a fixate function on the source pad.
124  * @set_caps: Notify subclass of changed output caps
125  * @decide_allocation: configure the allocation query
126  * @start: Start processing. Subclasses should open resources and prepare
127  *    to produce data. Implementation should call gst_base_src_start_complete()
128  *    when the operation completes, either from the current thread or any other
129  *    thread that finishes the start operation asynchronously.
130  * @stop: Stop processing. Subclasses should use this to close resources.
131  * @get_times: Given a buffer, return the start and stop time when it
132  *    should be pushed out. The base class will sync on the clock using
133  *    these times.
134  * @get_size: Return the total size of the resource, in the format set by
135  *     gst_base_src_set_format().
136  * @is_seekable: Check if the source can seek
137  * @prepare_seek_segment: Prepare the #GstSegment that will be passed to the
138  *   #GstBaseSrcClass::do_seek vmethod for executing a seek
139  *   request. Sub-classes should override this if they support seeking in
140  *   formats other than the configured native format. By default, it tries to
141  *   convert the seek arguments to the configured native format and prepare a
142  *   segment in that format.
143  * @do_seek: Perform seeking on the resource to the indicated segment.
144  * @unlock: Unlock any pending access to the resource. Subclasses should unblock
145  *    any blocked function ASAP. In particular, any `create()` function in
146  *    progress should be unblocked and should return GST_FLOW_FLUSHING. Any
147  *    future #GstBaseSrcClass::create function call should also return
148  *    GST_FLOW_FLUSHING until the #GstBaseSrcClass::unlock_stop function has
149  *    been called.
150  * @unlock_stop: Clear the previous unlock request. Subclasses should clear any
151  *    state they set during #GstBaseSrcClass::unlock, such as clearing command
152  *    queues.
153  * @query: Handle a requested query.
154  * @event: Override this to implement custom event handling.
155  * @create: Ask the subclass to create a buffer with offset and size.  When the
156  *   subclass returns GST_FLOW_OK, it MUST return a buffer of the requested size
157  *   unless fewer bytes are available because an EOS condition is near. No
158  *   buffer should be returned when the return value is different from
159  *   GST_FLOW_OK. A return value of GST_FLOW_EOS signifies that the end of
160  *   stream is reached. The default implementation will call
161  *   #GstBaseSrcClass::alloc and then call #GstBaseSrcClass::fill.
162  * @alloc: Ask the subclass to allocate a buffer with for offset and size. The
163  *   default implementation will create a new buffer from the negotiated allocator.
164  * @fill: Ask the subclass to fill the buffer with data for offset and size. The
165  *   passed buffer is guaranteed to hold the requested amount of bytes.
166  *
167  * Subclasses can override any of the available virtual methods or not, as
168  * needed. At the minimum, the @create method should be overridden to produce
169  * buffers.
170  */
171 struct _GstBaseSrcClass {
172   GstElementClass parent_class;
173 
174   /*< public >*/
175   /* virtual methods for subclasses */
176 
177   /**
178    * GstBaseSrcClass::get_caps:
179    * @filter: (in) (nullable):
180    *
181    * Called to get the caps to report.
182    */
183   GstCaps*      (*get_caps)     (GstBaseSrc *src, GstCaps *filter);
184   /* decide on caps */
185   gboolean      (*negotiate)    (GstBaseSrc *src);
186   /* called if, in negotiation, caps need fixating */
187   GstCaps *     (*fixate)       (GstBaseSrc *src, GstCaps *caps);
188   /* notify the subclass of new caps */
189   gboolean      (*set_caps)     (GstBaseSrc *src, GstCaps *caps);
190 
191   /* setup allocation query */
192   gboolean      (*decide_allocation)   (GstBaseSrc *src, GstQuery *query);
193 
194   /* start and stop processing, ideal for opening/closing the resource */
195   gboolean      (*start)        (GstBaseSrc *src);
196   gboolean      (*stop)         (GstBaseSrc *src);
197 
198   /**
199    * GstBaseSrcClass::get_times:
200    * @start: (out):
201    * @end: (out):
202    *
203    * Given @buffer, return @start and @end time when it should be pushed
204    * out. The base class will sync on the clock using these times.
205    */
206   void          (*get_times)    (GstBaseSrc *src, GstBuffer *buffer,
207                                  GstClockTime *start, GstClockTime *end);
208 
209   /**
210    * GstBaseSrcClass::get_size:
211    * @size: (out):
212    *
213    * Get the total size of the resource in the format set by
214    * gst_base_src_set_format().
215    *
216    * Returns: %TRUE if the size is available and has been set.
217    */
218   gboolean      (*get_size)     (GstBaseSrc *src, guint64 *size);
219 
220   /* check if the resource is seekable */
221   gboolean      (*is_seekable)  (GstBaseSrc *src);
222 
223   /* Prepare the segment on which to perform do_seek(), converting to the
224    * current basesrc format. */
225   gboolean      (*prepare_seek_segment) (GstBaseSrc *src, GstEvent *seek,
226                                          GstSegment *segment);
227   /* notify subclasses of a seek */
228   gboolean      (*do_seek)      (GstBaseSrc *src, GstSegment *segment);
229 
230   /* unlock any pending access to the resource. subclasses should unlock
231    * any function ASAP. */
232   gboolean      (*unlock)       (GstBaseSrc *src);
233   /* Clear any pending unlock request, as we succeeded in unlocking */
234   gboolean      (*unlock_stop)  (GstBaseSrc *src);
235 
236   /* notify subclasses of a query */
237   gboolean      (*query)        (GstBaseSrc *src, GstQuery *query);
238 
239   /* notify subclasses of an event */
240   gboolean      (*event)        (GstBaseSrc *src, GstEvent *event);
241 
242   /**
243    * GstBaseSrcClass::create:
244    * @buf: (inout):
245    *
246    * Ask the subclass to create a buffer with @offset and @size, the default
247    * implementation will call alloc if no allocated @buf is provided and then call fill.
248    */
249   GstFlowReturn (*create)       (GstBaseSrc *src, guint64 offset, guint size,
250                                  GstBuffer **buf);
251   /**
252    * GstBaseSrcClass::alloc:
253    * @buf: (out):
254    *
255    * Ask the subclass to allocate an output buffer with @offset and @size, the default
256    * implementation will use the negotiated allocator.
257    */
258   GstFlowReturn (*alloc)        (GstBaseSrc *src, guint64 offset, guint size,
259                                  GstBuffer **buf);
260   /* ask the subclass to fill the buffer with data from offset and size */
261   GstFlowReturn (*fill)         (GstBaseSrc *src, guint64 offset, guint size,
262                                  GstBuffer *buf);
263 
264   /*< private >*/
265   gpointer       _gst_reserved[GST_PADDING_LARGE];
266 };
267 
268 GST_BASE_API
269 GType           gst_base_src_get_type (void);
270 
271 GST_BASE_API
272 GstFlowReturn   gst_base_src_wait_playing     (GstBaseSrc *src);
273 
274 GST_BASE_API
275 void            gst_base_src_set_live         (GstBaseSrc *src, gboolean live);
276 
277 GST_BASE_API
278 gboolean        gst_base_src_is_live          (GstBaseSrc *src);
279 
280 GST_BASE_API
281 void            gst_base_src_set_format       (GstBaseSrc *src, GstFormat format);
282 
283 GST_BASE_API
284 void            gst_base_src_set_dynamic_size (GstBaseSrc * src, gboolean dynamic);
285 
286 GST_BASE_API
287 void            gst_base_src_set_automatic_eos (GstBaseSrc * src, gboolean automatic_eos);
288 
289 GST_BASE_API
290 void            gst_base_src_set_async        (GstBaseSrc *src, gboolean async);
291 
292 GST_BASE_API
293 gboolean        gst_base_src_is_async         (GstBaseSrc *src);
294 
295 GST_BASE_API
296 gboolean        gst_base_src_negotiate        (GstBaseSrc *src);
297 
298 GST_BASE_API
299 void            gst_base_src_start_complete   (GstBaseSrc * basesrc, GstFlowReturn ret);
300 
301 GST_BASE_API
302 GstFlowReturn   gst_base_src_start_wait       (GstBaseSrc * basesrc);
303 
304 GST_BASE_API
305 gboolean        gst_base_src_query_latency    (GstBaseSrc *src, gboolean * live,
306                                                GstClockTime * min_latency,
307                                                GstClockTime * max_latency);
308 GST_BASE_API
309 void            gst_base_src_set_blocksize    (GstBaseSrc *src, guint blocksize);
310 
311 GST_BASE_API
312 guint           gst_base_src_get_blocksize    (GstBaseSrc *src);
313 
314 GST_BASE_API
315 void            gst_base_src_set_do_timestamp (GstBaseSrc *src, gboolean timestamp);
316 
317 GST_BASE_API
318 gboolean        gst_base_src_get_do_timestamp (GstBaseSrc *src);
319 
320 GST_BASE_API
321 gboolean        gst_base_src_new_seamless_segment (GstBaseSrc *src, gint64 start, gint64 stop, gint64 time);
322 
323 GST_BASE_API
324 gboolean        gst_base_src_new_segment      (GstBaseSrc *src,
325                                                const GstSegment * segment);
326 
327 GST_BASE_API
328 gboolean        gst_base_src_set_caps         (GstBaseSrc *src, GstCaps *caps);
329 
330 GST_BASE_API
331 GstBufferPool * gst_base_src_get_buffer_pool  (GstBaseSrc *src);
332 
333 GST_BASE_API
334 void            gst_base_src_get_allocator    (GstBaseSrc *src,
335                                                GstAllocator **allocator,
336                                                GstAllocationParams *params);
337 
338 GST_BASE_API
339 void            gst_base_src_submit_buffer_list (GstBaseSrc    * src,
340                                                  GstBufferList * buffer_list);
341 
342 G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBaseSrc, gst_object_unref)
343 
344 G_END_DECLS
345 
346 #endif /* __GST_BASE_SRC_H__ */
347