1/* GStreamer
2 * Copyright (C) 2010 Wim Taymans <wim.taymans@gmail.com>
3 *
4 * gstbufferpool.h: Header for GstBufferPool object
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22
23#ifndef __GST_BUFFER_POOL_H__
24#define __GST_BUFFER_POOL_H__
25
26#include <gst/gstminiobject.h>
27#include <gst/gstpad.h>
28#include <gst/gstbuffer.h>
29
30G_BEGIN_DECLS
31
32typedef struct _GstBufferPoolPrivate GstBufferPoolPrivate;
33typedef struct _GstBufferPoolClass GstBufferPoolClass;
34
35#define GST_TYPE_BUFFER_POOL (gst_buffer_pool_get_type())
36#define GST_IS_BUFFER_POOL(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_BUFFER_POOL))
37#define GST_IS_BUFFER_POOL_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_BUFFER_POOL))
38#define GST_BUFFER_POOL_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BUFFER_POOL, GstBufferPoolClass))
39#define GST_BUFFER_POOL(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_BUFFER_POOL, GstBufferPool))
40#define GST_BUFFER_POOL_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_BUFFER_POOL, GstBufferPoolClass))
41#define GST_BUFFER_POOL_CAST(obj) ((GstBufferPool *)(obj))
42
43/**
44 * GstBufferPoolAcquireFlags:
45 * @GST_BUFFER_POOL_ACQUIRE_FLAG_NONE: no flags
46 * @GST_BUFFER_POOL_ACQUIRE_FLAG_KEY_UNIT: buffer is keyframe
47 * @GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT: when the bufferpool is empty, acquire_buffer
48 * will by default block until a buffer is released into the pool again. Setting
49 * this flag makes acquire_buffer return #GST_FLOW_EOS instead of blocking.
50 * @GST_BUFFER_POOL_ACQUIRE_FLAG_DISCONT: buffer is discont
51 * @GST_BUFFER_POOL_ACQUIRE_FLAG_LAST: last flag, subclasses can use private flags
52 * starting from this value.
53 *
54 * Additional flags to control the allocation of a buffer
55 */
56typedef enum {
57 GST_BUFFER_POOL_ACQUIRE_FLAG_NONE = 0,
58 GST_BUFFER_POOL_ACQUIRE_FLAG_KEY_UNIT = (1 << 0),
59 GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT = (1 << 1),
60 GST_BUFFER_POOL_ACQUIRE_FLAG_DISCONT = (1 << 2),
61 GST_BUFFER_POOL_ACQUIRE_FLAG_LAST = (1 << 16),
62} GstBufferPoolAcquireFlags;
63
64typedef struct _GstBufferPoolAcquireParams GstBufferPoolAcquireParams;
65
66/**
67 * GstBufferPoolAcquireParams:
68 * @format: the format of @start and @stop
69 * @start: the start position
70 * @stop: the stop position
71 * @flags: additional flags
72 *
73 * Parameters passed to the gst_buffer_pool_acquire_buffer() function to control the
74 * allocation of the buffer.
75 *
76 * The default implementation ignores the @start and @stop members but other
77 * implementations can use this extra information to decide what buffer to
78 * return.
79 */
80struct _GstBufferPoolAcquireParams {
81 GstFormat format;
82 gint64 start;
83 gint64 stop;
84 GstBufferPoolAcquireFlags flags;
85
86 /*< private >*/
87 gpointer _gst_reserved[GST_PADDING];
88};
89
90/**
91 * GST_BUFFER_POOL_IS_FLUSHING:
92 * @pool: a GstBufferPool
93 *
94 * Check if the bufferpool is flushing. Subclasses might want to check the
95 * state of the pool in the acquire function.
96 */
97#define GST_BUFFER_POOL_IS_FLUSHING(pool) (g_atomic_int_get (&pool->flushing))
98
99/**
100 * GstBufferPool:
101 *
102 * The structure of a #GstBufferPool. Use the associated macros to access the public
103 * variables.
104 */
105struct _GstBufferPool {
106 GstObject object;
107
108 /*< protected >*/
109 gint flushing;
110
111 /*< private >*/
112 GstBufferPoolPrivate *priv;
113
114 gpointer _gst_reserved[GST_PADDING];
115};
116
117/**
118 * GstBufferPoolClass:
119 * @object_class: Object parent class
120 * @get_options: get a list of options supported by this pool
121 * @set_config: apply the bufferpool configuration. The default configuration
122 * will parse the default config parameters
123 * @start: start the bufferpool. The default implementation will preallocate
124 * min-buffers buffers and put them in the queue
125 * @stop: stop the bufferpool. the default implementation will free the
126 * preallocated buffers. This function is called when all the buffers are
127 * returned to the pool.
128 * @acquire_buffer: get a new buffer from the pool. The default implementation
129 * will take a buffer from the queue and optionally wait for a buffer to
130 * be released when there are no buffers available.
131 * @alloc_buffer: allocate a buffer. the default implementation allocates
132 * buffers from the configured memory allocator and with the configured
133 * parameters. All metadata that is present on the allocated buffer will
134 * be marked as #GST_META_FLAG_POOLED and #GST_META_FLAG_LOCKED and will
135 * not be removed from the buffer in @reset_buffer. The buffer should
136 * have the GST_BUFFER_FLAG_TAG_MEMORY cleared.
137 * @reset_buffer: reset the buffer to its state when it was freshly allocated.
138 * The default implementation will clear the flags, timestamps and
139 * will remove the metadata without the #GST_META_FLAG_POOLED flag (even
140 * the metadata with #GST_META_FLAG_LOCKED). If the
141 * #GST_BUFFER_FLAG_TAG_MEMORY was set, this function can also try to
142 * restore the memory and clear the #GST_BUFFER_FLAG_TAG_MEMORY again.
143 * @release_buffer: release a buffer back in the pool. The default
144 * implementation will put the buffer back in the queue and notify any
145 * blocking acquire_buffer calls when the #GST_BUFFER_FLAG_TAG_MEMORY
146 * is not set on the buffer. If #GST_BUFFER_FLAG_TAG_MEMORY is set, the
147 * buffer will be freed with @free_buffer.
148 * @free_buffer: free a buffer. The default implementation unrefs the buffer.
149 * @flush_start: enter the flushing state. (Since 1.4)
150 * @flush_stop: leave the flushign state. (Since 1.4)
151 *
152 * The GstBufferPool class.
153 */
154struct _GstBufferPoolClass {
155 GstObjectClass object_class;
156
157 /*< public >*/
158 const gchar ** (*get_options) (GstBufferPool *pool);
159 gboolean (*set_config) (GstBufferPool *pool, GstStructure *config);
160
161 gboolean (*start) (GstBufferPool *pool);
162 gboolean (*stop) (GstBufferPool *pool);
163
164 GstFlowReturn (*acquire_buffer) (GstBufferPool *pool, GstBuffer **buffer,
165 GstBufferPoolAcquireParams *params);
166 GstFlowReturn (*alloc_buffer) (GstBufferPool *pool, GstBuffer **buffer,
167 GstBufferPoolAcquireParams *params);
168 void (*reset_buffer) (GstBufferPool *pool, GstBuffer *buffer);
169 void (*release_buffer) (GstBufferPool *pool, GstBuffer *buffer);
170 void (*free_buffer) (GstBufferPool *pool, GstBuffer *buffer);
171 void (*flush_start) (GstBufferPool *pool);
172 void (*flush_stop) (GstBufferPool *pool);
173
174 /*< private >*/
175 gpointer _gst_reserved[GST_PADDING - 2];
176};
177
178GST_API
179GType gst_buffer_pool_get_type (void);
180
181/* allocation */
182
183GST_API
184GstBufferPool * gst_buffer_pool_new (void);
185
186/* state management */
187
188GST_API
189gboolean gst_buffer_pool_set_active (GstBufferPool *pool, gboolean active);
190
191GST_API
192gboolean gst_buffer_pool_is_active (GstBufferPool *pool);
193
194GST_API
195gboolean gst_buffer_pool_set_config (GstBufferPool *pool, GstStructure *config);
196
197GST_API
198GstStructure * gst_buffer_pool_get_config (GstBufferPool *pool);
199
200GST_API
201const gchar ** gst_buffer_pool_get_options (GstBufferPool *pool);
202
203GST_API
204gboolean gst_buffer_pool_has_option (GstBufferPool *pool, const gchar *option);
205
206GST_API
207void gst_buffer_pool_set_flushing (GstBufferPool *pool, gboolean flushing);
208
209/* helpers for configuring the config structure */
210
211GST_API
212void gst_buffer_pool_config_set_params (GstStructure *config, GstCaps *caps,
213 guint size, guint min_buffers, guint max_buffers);
214
215GST_API
216gboolean gst_buffer_pool_config_get_params (GstStructure *config, GstCaps **caps,
217 guint *size, guint *min_buffers, guint *max_buffers);
218
219GST_API
220void gst_buffer_pool_config_set_allocator (GstStructure *config, GstAllocator *allocator,
221 const GstAllocationParams *params);
222
223GST_API
224gboolean gst_buffer_pool_config_get_allocator (GstStructure *config, GstAllocator **allocator,
225 GstAllocationParams *params);
226
227/* options */
228
229GST_API
230guint gst_buffer_pool_config_n_options (GstStructure *config);
231
232GST_API
233void gst_buffer_pool_config_add_option (GstStructure *config, const gchar *option);
234
235GST_API
236const gchar * gst_buffer_pool_config_get_option (GstStructure *config, guint index);
237
238GST_API
239gboolean gst_buffer_pool_config_has_option (GstStructure *config, const gchar *option);
240
241GST_API
242gboolean gst_buffer_pool_config_validate_params (GstStructure *config, GstCaps *caps,
243 guint size, guint min_buffers, guint max_buffers);
244
245/* buffer management */
246
247GST_API
248GstFlowReturn gst_buffer_pool_acquire_buffer (GstBufferPool *pool, GstBuffer **buffer,
249 GstBufferPoolAcquireParams *params);
250
251GST_API
252void gst_buffer_pool_release_buffer (GstBufferPool *pool, GstBuffer *buffer);
253
254G_END_DECLS
255
256#endif /* __GST_BUFFER_POOL_H__ */
257