2 * Copyright (C) 2009 Wim Taymans <wim.taymans@gmail.be>
4 * gstmemory.h: Header for memory blocks
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.
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.
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., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
23 #ifndef __GST_MEMORY_H__
24 #define __GST_MEMORY_H__
26 #include <gst/gstconfig.h>
28 #include <glib-object.h>
32 #define GST_TYPE_MEMORY (gst_memory_get_type())
33 GType gst_memory_get_type(void);
35 typedef struct _GstMemory GstMemory;
36 typedef struct _GstMemoryInfo GstMemoryInfo;
37 typedef struct _GstAllocator GstAllocator;
39 GST_EXPORT gsize gst_memory_alignment;
43 * @GST_MEMORY_FLAG_READONLY: memory is readonly. It is not allowed to map the
44 * memory with #GST_MAP_WRITE.
45 * @GST_MEMORY_FLAG_NO_SHARE: memory must not be shared. Copies will have to be
46 * made when this memory needs to be shared between buffers.
47 * @GST_MEMORY_FLAG_LAST: first flag that can be used for custom purposes
49 * Flags for wrapped memory.
52 GST_MEMORY_FLAG_READONLY = (1 << 0),
53 GST_MEMORY_FLAG_NO_SHARE = (1 << 1),
55 GST_MEMORY_FLAG_LAST = (1 << 16)
60 * @allocator: pointer to the #GstAllocator
61 * @flags: memory flags
63 * @parent: parent memory block
64 * @state: private state
65 * @maxsize: the maximum size allocated
66 * @align: the alignment of the memory
67 * @offset: the offset where valid data starts
68 * @size: the size of valid data
70 * Base structure for memory implementations. Custom memory will put this structure
71 * as the first member of their structure.
74 const GstAllocator *allocator;
88 * @GST_MAP_READ: map for read access
89 * @GST_MAP_WRITE: map for write access
90 * @GST_MAP_FLAG_LAST: first flag that can be used for custom purposes
92 * Flags used when mapping memory
95 GST_MAP_READ = (1 << 0),
96 GST_MAP_WRITE = (1 << 1),
98 GST_MAP_FLAG_LAST = (1 << 16)
104 * Map for readwrite access
106 #define GST_MAP_READWRITE (GST_MAP_READ | GST_MAP_WRITE)
109 * GST_ALLOCATOR_SYSMEM:
111 * The allocator name for the default system memory allocator
113 #define GST_ALLOCATOR_SYSMEM "SystemMemory"
116 * GstMemoryAllocFunction:
117 * @allocator: a #GstAllocator
118 * @maxsize: the maxsize
119 * @align: the alignment
120 * @user_data: user data
122 * Allocate a new #GstMemory from @allocator that can hold at least @maxsize bytes
123 * and is aligned to (@align + 1) bytes.
125 * @user_data is the data that was used when registering @allocator.
127 * Returns: a newly allocated #GstMemory. Free with gst_memory_unref()
129 typedef GstMemory * (*GstMemoryAllocFunction) (const GstAllocator *allocator,
130 gsize maxsize, gsize align,
134 * GstMemoryMapFunction:
136 * @maxsize: size to map
137 * @flags: access mode for the memory
139 * Get the memory of @mem that can be accessed according to the mode specified
140 * in @flags. The function should return a pointer that contains at least
143 * Returns: a pointer to memory of which at least @maxsize bytes can be
144 * accessed according to the access pattern in @flags.
146 typedef gpointer (*GstMemoryMapFunction) (GstMemory *mem, gsize maxsize, GstMapFlags flags);
149 * GstMemoryUnmapFunction:
152 * Return the pointer previously retrieved with gst_memory_map().
154 * Returns: %TRUE on success.
156 typedef void (*GstMemoryUnmapFunction) (GstMemory *mem);
159 * GstMemoryFreeFunction:
162 * Free the memory used by @mem. This function is usually called when the
163 * refcount of the @mem has reached 0.
165 typedef void (*GstMemoryFreeFunction) (GstMemory *mem);
168 * GstMemoryCopyFunction:
171 * @size: a size or -1
173 * Copy @size bytes from @mem starting at @offset and return them wrapped in a
174 * new GstMemory object.
175 * If @size is set to -1, all bytes starting at @offset are copied.
177 * Returns: a new #GstMemory object wrapping a copy of the requested region in
180 typedef GstMemory * (*GstMemoryCopyFunction) (GstMemory *mem, gssize offset, gssize size);
183 * GstMemoryShareFunction:
186 * @size: a size or -1
188 * Share @size bytes from @mem starting at @offset and return them wrapped in a
189 * new GstMemory object. If @size is set to -1, all bytes starting at @offset are
190 * shared. This function does not make a copy of the bytes in @mem.
192 * Returns: a new #GstMemory object sharing the requested region in @mem.
194 typedef GstMemory * (*GstMemoryShareFunction) (GstMemory *mem, gssize offset, gssize size);
197 * GstMemoryIsSpanFunction:
198 * @mem1: a #GstMemory
199 * @mem2: a #GstMemory
200 * @offset: a result offset
202 * Check if @mem1 and @mem2 occupy contiguous memory and return the offset of
203 * @mem1 in the parent buffer in @offset.
205 * Returns: %TRUE if @mem1 and @mem2 are in contiguous memory.
207 typedef gboolean (*GstMemoryIsSpanFunction) (GstMemory *mem1, GstMemory *mem2, gsize *offset);
211 * @alloc: the implementation of the GstMemoryAllocFunction
212 * @map: the implementation of the GstMemoryMapFunction
213 * @unmap: the implementation of the GstMemoryUnmapFunction
214 * @free: the implementation of the GstMemoryFreeFunction
215 * @copy: the implementation of the GstMemoryCopyFunction
216 * @share: the implementation of the GstMemoryShareFunction
217 * @is_span: the implementation of the GstMemoryIsSpanFunction
218 * @user_data: generic user data for the allocator
220 * The #GstMemoryInfo is used to register new memory allocators and contain
221 * the implementations for various memory operations.
223 struct _GstMemoryInfo {
224 GstMemoryAllocFunction alloc;
225 GstMemoryMapFunction map;
226 GstMemoryUnmapFunction unmap;
227 GstMemoryFreeFunction free;
229 GstMemoryCopyFunction copy;
230 GstMemoryShareFunction share;
231 GstMemoryIsSpanFunction is_span;
236 gpointer _gst_reserved[GST_PADDING];
240 const GstAllocator * gst_allocator_register (const gchar *name, const GstMemoryInfo *info);
241 const GstAllocator * gst_allocator_find (const gchar *name);
243 void gst_allocator_set_default (const GstAllocator * allocator);
245 /* allocating memory blocks */
246 GstMemory * gst_allocator_alloc (const GstAllocator * allocator,
247 gsize maxsize, gsize align);
249 GstMemory * gst_memory_new_wrapped (GstMemoryFlags flags, gpointer data, GFreeFunc free_func,
250 gsize maxsize, gsize offset, gsize size);
253 GstMemory * gst_memory_ref (GstMemory *mem);
254 void gst_memory_unref (GstMemory *mem);
256 /* getting/setting memory properties */
257 gsize gst_memory_get_sizes (GstMemory *mem, gsize *offset, gsize *maxsize);
258 void gst_memory_resize (GstMemory *mem, gssize offset, gsize size);
260 /* retrieving data */
261 gboolean gst_memory_is_writable (GstMemory *mem);
263 gpointer gst_memory_map (GstMemory *mem, gsize *size, gsize *maxsize,
265 void gst_memory_unmap (GstMemory *mem);
267 /* copy and subregions */
268 GstMemory * gst_memory_copy (GstMemory *mem, gssize offset, gssize size);
269 GstMemory * gst_memory_share (GstMemory *mem, gssize offset, gssize size);
272 gboolean gst_memory_is_span (GstMemory *mem1, GstMemory *mem2, gsize *offset);
276 #endif /* __GST_MEMORY_H__ */