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., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
22 */
24 #ifndef __GST_BASE_SRC_H__
25 #define __GST_BASE_SRC_H__
27 #include <gst/gst.h>
29 G_BEGIN_DECLS
31 #define GST_TYPE_BASE_SRC (gst_base_src_get_type())
32 #define GST_BASE_SRC(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BASE_SRC,GstBaseSrc))
33 #define GST_BASE_SRC_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BASE_SRC,GstBaseSrcClass))
34 #define GST_BASE_SRC_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BASE_SRC, GstBaseSrcClass))
35 #define GST_IS_BASE_SRC(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BASE_SRC))
36 #define GST_IS_BASE_SRC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BASE_SRC))
37 #define GST_BASE_SRC_CAST(obj) ((GstBaseSrc *)(obj))
39 /**
40 * GstBaseSrcFlags:
41 * @GST_BASE_SRC_STARTED: has source been started
42 * @GST_BASE_SRC_FLAG_LAST: offset to define more flags
43 *
44 * The #GstElement flags that a basesrc element may have.
45 */
46 typedef enum {
47 GST_BASE_SRC_STARTED = (GST_ELEMENT_FLAG_LAST << 0),
48 /* padding */
49 GST_BASE_SRC_FLAG_LAST = (GST_ELEMENT_FLAG_LAST << 2)
50 } GstBaseSrcFlags;
52 typedef struct _GstBaseSrc GstBaseSrc;
53 typedef struct _GstBaseSrcClass GstBaseSrcClass;
54 typedef struct _GstBaseSrcPrivate GstBaseSrcPrivate;
56 /**
57 * GST_BASE_SRC_PAD:
58 * @obj: base source instance
59 *
60 * Gives the pointer to the #GstPad object of the element.
61 */
62 #define GST_BASE_SRC_PAD(obj) (GST_BASE_SRC_CAST (obj)->srcpad)
65 /**
66 * GstBaseSrc:
67 *
68 * The opaque #GstBaseSrc data structure.
69 */
70 struct _GstBaseSrc {
71 GstElement element;
73 /*< protected >*/
74 GstPad *srcpad;
76 /* available to subclass implementations */
77 /* MT-protected (with LIVE_LOCK) */
78 GMutex *live_lock;
79 GCond *live_cond;
80 gboolean is_live;
81 gboolean live_running;
83 /* MT-protected (with LOCK) */
84 gint blocksize; /* size of buffers when operating push based */
85 gboolean can_activate_push; /* some scheduling properties */
86 GstActivateMode pad_mode;
87 gboolean seekable; /* not used anymore */
88 gboolean random_access;
90 GstClockID clock_id; /* for syncing */
91 GstClockTime end_time;
93 /* MT-protected (with STREAM_LOCK *and* OBJECT_LOCK) */
94 GstSegment segment;
95 /* MT-protected (with STREAM_LOCK) */
96 gboolean need_newsegment;
98 guint64 offset; /* current offset in the resource, unused */
99 guint64 size; /* total size of the resource, unused */
101 gint num_buffers;
102 gint num_buffers_left;
104 /*< private >*/
105 union {
106 struct {
107 /* FIXME: those fields should be moved into the private struct */
108 gboolean typefind;
109 gboolean running;
110 GstEvent *pending_seek;
111 } ABI;
112 gpointer _gst_reserved[GST_PADDING_LARGE-1];
113 } data;
115 GstBaseSrcPrivate *priv;
116 };
118 /**
119 * GstBaseSrcClass:
120 * @parent_class: Element parent class
121 * @get_caps: Called to get the caps to report
122 * @set_caps: Notify subclass of changed output caps
123 * @negotiate: Negotiated the caps with the peer.
124 * @newsegment: Generate and send a new_segment event (UNUSED)
125 * @start: Start processing. Subclasses should open resources and prepare
126 * to produce data.
127 * @stop: Stop processing. Subclasses should use this to close resources.
128 * @get_times: Given a buffer, return the start and stop time when it
129 * should be pushed out. The base class will sync on the clock using
130 * these times.
131 * @get_size: Return the total size of the resource, in the configured format.
132 * @is_seekable: Check if the source can seek
133 * @unlock: Unlock any pending access to the resource. Subclasses should
134 * unblock any blocked function ASAP. In particular, any create() function in
135 * progress should be unblocked and should return GST_FLOW_WRONG_STATE. Any
136 * future @create<!-- -->() function call should also return GST_FLOW_WRONG_STATE
137 * until the @unlock_stop<!-- -->() function has been called.
138 * @unlock_stop: Clear the previous unlock request. Subclasses should clear
139 * any state they set during unlock(), such as clearing command queues.
140 * @event: Override this to implement custom event handling.
141 * @create: Ask the subclass to create a buffer with offset and size.
142 * When the subclass returns GST_FLOW_OK, it MUST return a buffer of the
143 * requested size unless fewer bytes are available because an EOS condition
144 * is near. No buffer should be returned when the return value is different
145 * from GST_FLOW_OK. A return value of GST_FLOW_UNEXPECTED signifies that the
146 * end of stream is reached.
147 * @do_seek: Perform seeking on the resource to the indicated segment.
148 * @prepare_seek_segment: Prepare the GstSegment that will be passed to the
149 * do_seek vmethod for executing a seek request. Sub-classes should override
150 * this if they support seeking in formats other than the configured native
151 * format. By default, it tries to convert the seek arguments to the
152 * configured native format and prepare a segment in that format.
153 * Since: 0.10.13
154 * @query: Handle a requested query.
155 * @check_get_range: Check whether the source would support pull-based
156 * operation if it were to be opened now. This vfunc is optional, but
157 * should be implemented if possible to avoid unnecessary start/stop
158 * cycles. The default implementation will open and close the resource
159 * to find out whether get_range is supported, and that is usually
160 * undesirable.
161 * @fixate: Called during negotiation if caps need fixating. Implement instead of
162 * setting a fixate function on the source pad.
163 *
164 * Subclasses can override any of the available virtual methods or not, as
165 * needed. At the minimum, the @create method should be overridden to produce
166 * buffers.
167 */
168 struct _GstBaseSrcClass {
169 GstElementClass parent_class;
171 /*< public >*/
172 /* virtual methods for subclasses */
174 /* get caps from subclass */
175 GstCaps* (*get_caps) (GstBaseSrc *src);
176 /* notify the subclass of new caps */
177 gboolean (*set_caps) (GstBaseSrc *src, GstCaps *caps);
179 /* decide on caps */
180 gboolean (*negotiate) (GstBaseSrc *src);
182 /* generate and send a newsegment (UNUSED) */
183 gboolean (*newsegment) (GstBaseSrc *src);
185 /* start and stop processing, ideal for opening/closing the resource */
186 gboolean (*start) (GstBaseSrc *src);
187 gboolean (*stop) (GstBaseSrc *src);
189 /* given a buffer, return start and stop time when it should be pushed
190 * out. The base class will sync on the clock using these times. */
191 void (*get_times) (GstBaseSrc *src, GstBuffer *buffer,
192 GstClockTime *start, GstClockTime *end);
194 /* get the total size of the resource in bytes */
195 gboolean (*get_size) (GstBaseSrc *src, guint64 *size);
197 /* check if the resource is seekable */
198 gboolean (*is_seekable) (GstBaseSrc *src);
199 /* unlock any pending access to the resource. subclasses should unlock
200 * any function ASAP. */
201 gboolean (*unlock) (GstBaseSrc *src);
203 /* notify subclasses of an event */
204 gboolean (*event) (GstBaseSrc *src, GstEvent *event);
206 /* ask the subclass to create a buffer with offset and size */
207 GstFlowReturn (*create) (GstBaseSrc *src, guint64 offset, guint size,
208 GstBuffer **buf);
210 /* additions that change padding... */
211 /* notify subclasses of a seek */
212 gboolean (*do_seek) (GstBaseSrc *src, GstSegment *segment);
213 /* notify subclasses of a query */
214 gboolean (*query) (GstBaseSrc *src, GstQuery *query);
216 /* check whether the source would support pull-based operation if
217 * it were to be opened now. This vfunc is optional, but should be
218 * implemented if possible to avoid unnecessary start/stop cycles.
219 * The default implementation will open and close the resource to
220 * find out whether get_range is supported and that is usually
221 * undesirable. */
222 gboolean (*check_get_range) (GstBaseSrc *src);
224 /* called if, in negotiation, caps need fixating */
225 void (*fixate) (GstBaseSrc *src, GstCaps *caps);
227 /* Clear any pending unlock request, as we succeeded in unlocking */
228 gboolean (*unlock_stop) (GstBaseSrc *src);
230 /* Prepare the segment on which to perform do_seek(), converting to the
231 * current basesrc format. */
232 gboolean (*prepare_seek_segment) (GstBaseSrc *src, GstEvent *seek,
233 GstSegment *segment);
235 /*< private >*/
236 gpointer _gst_reserved[GST_PADDING_LARGE - 6];
237 };
239 GType gst_base_src_get_type (void);
241 GstFlowReturn gst_base_src_wait_playing (GstBaseSrc *src);
243 void gst_base_src_set_live (GstBaseSrc *src, gboolean live);
244 gboolean gst_base_src_is_live (GstBaseSrc *src);
246 void gst_base_src_set_format (GstBaseSrc *src, GstFormat format);
248 gboolean gst_base_src_query_latency (GstBaseSrc *src, gboolean * live,
249 GstClockTime * min_latency,
250 GstClockTime * max_latency);
252 void gst_base_src_set_blocksize (GstBaseSrc *src, gulong blocksize);
253 gulong gst_base_src_get_blocksize (GstBaseSrc *src);
255 void gst_base_src_set_do_timestamp (GstBaseSrc *src, gboolean timestamp);
256 gboolean gst_base_src_get_do_timestamp (GstBaseSrc *src);
258 gboolean gst_base_src_new_seamless_segment (GstBaseSrc *src, gint64 start, gint64 stop, gint64 position);
259 G_END_DECLS
261 #endif /* __GST_BASE_SRC_H__ */