2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstbuffer.h: Header for GstBuffer object
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
24 #ifndef __GST_BUFFER_H__
25 #define __GST_BUFFER_H__
27 #include <gst/gstminiobject.h>
28 #include <gst/gstclock.h>
29 #include <gst/gstcaps.h>
33 typedef struct _GstBuffer GstBuffer;
34 typedef struct _GstBufferClass GstBufferClass;
37 * GST_BUFFER_TRACE_NAME:
39 * The name used for tracing memory allocations.
41 #define GST_BUFFER_TRACE_NAME "GstBuffer"
43 #define GST_TYPE_BUFFER (gst_buffer_get_type())
44 #define GST_IS_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_BUFFER))
45 #define GST_IS_BUFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_BUFFER))
46 #define GST_BUFFER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BUFFER, GstBufferClass))
47 #define GST_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_BUFFER, GstBuffer))
48 #define GST_BUFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_BUFFER, GstBufferClass))
49 #define GST_BUFFER_CAST(obj) ((GstBuffer *)(obj))
55 * A flags word containing #GstBufferFlag flags set on this buffer.
57 #define GST_BUFFER_FLAGS(buf) GST_MINI_OBJECT_FLAGS(buf)
59 * GST_BUFFER_FLAG_IS_SET:
61 * @flag: the #GstBufferFlag to check.
63 * Gives the status of a specific flag on a buffer.
65 #define GST_BUFFER_FLAG_IS_SET(buf,flag) GST_MINI_OBJECT_FLAG_IS_SET (buf, flag)
67 * GST_BUFFER_FLAG_SET:
69 * @flag: the #GstBufferFlag to set.
71 * Sets a buffer flag on a buffer.
73 #define GST_BUFFER_FLAG_SET(buf,flag) GST_MINI_OBJECT_FLAG_SET (buf, flag)
75 * GST_BUFFER_FLAG_UNSET:
77 * @flag: the #GstBufferFlag to clear.
79 * Clears a buffer flag.
81 #define GST_BUFFER_FLAG_UNSET(buf,flag) GST_MINI_OBJECT_FLAG_UNSET (buf, flag)
87 * A pointer to the data element of this buffer.
89 #define GST_BUFFER_DATA(buf) (GST_BUFFER_CAST(buf)->data)
94 * The size in bytes of the data in this buffer.
96 #define GST_BUFFER_SIZE(buf) (GST_BUFFER_CAST(buf)->size)
98 * GST_BUFFER_TIMESTAMP:
99 * @buf: a #GstBuffer.:
101 * The timestamp in nanoseconds (as a #GstClockTime) of the data in the buffer.
102 * Value will be %GST_CLOCK_TIME_NONE if the timestamp is unknown.
105 #define GST_BUFFER_TIMESTAMP(buf) (GST_BUFFER_CAST(buf)->timestamp)
107 * GST_BUFFER_DURATION:
108 * @buf: a #GstBuffer.
110 * The duration in nanoseconds (as a #GstClockTime) of the data in the buffer.
111 * Value will be %GST_CLOCK_TIME_NONE if the duration is unknown.
113 #define GST_BUFFER_DURATION(buf) (GST_BUFFER_CAST(buf)->duration)
116 * @buf: a #GstBuffer.
118 * The caps for this buffer.
120 #define GST_BUFFER_CAPS(buf) (GST_BUFFER_CAST(buf)->caps)
123 * @buf: a #GstBuffer.
125 * The offset in the source file of the beginning of this buffer.
127 #define GST_BUFFER_OFFSET(buf) (GST_BUFFER_CAST(buf)->offset)
129 * GST_BUFFER_OFFSET_END:
130 * @buf: a #GstBuffer.
132 * The offset in the source file of the end of this buffer.
134 #define GST_BUFFER_OFFSET_END(buf) (GST_BUFFER_CAST(buf)->offset_end)
136 * GST_BUFFER_MALLOCDATA:
137 * @buf: a #GstBuffer.
139 * A pointer to any data allocated for this buffer using g_malloc(). If this is
140 * non-NULL, this memory will be freed at the end of the buffer's lifecycle
141 * (i.e. when its refcount becomes zero).
143 #define GST_BUFFER_MALLOCDATA(buf) (GST_BUFFER_CAST(buf)->malloc_data)
145 * GST_BUFFER_FREE_FUNC:
146 * @buf: a #GstBuffer.
148 * A pointer to a function that will be called on the buffer's malloc_data when
149 * this buffer is finalized. Defaults to g_free().
151 * Note that the free function only affects the buffer's malloc_data; if the
152 * buffer's malloc_data is %NULL, the function will not be called.
156 #define GST_BUFFER_FREE_FUNC(buf) (GST_BUFFER_CAST(buf)->free_func)
159 * GST_BUFFER_OFFSET_NONE:
161 * Constant for no-offset return results.
163 #define GST_BUFFER_OFFSET_NONE ((guint64)-1)
166 * GST_BUFFER_DURATION_IS_VALID:
167 * @buffer: a #GstBuffer
169 * Tests if the duration is known.
171 #define GST_BUFFER_DURATION_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer)))
173 * GST_BUFFER_TIMESTAMP_IS_VALID:
174 * @buffer: a #GstBuffer
176 * Tests if the timestamp is known.
178 #define GST_BUFFER_TIMESTAMP_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buffer)))
180 * GST_BUFFER_OFFSET_IS_VALID:
181 * @buffer: a #GstBuffer
183 * Tests if the start offset is known.
185 #define GST_BUFFER_OFFSET_IS_VALID(buffer) (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE)
187 * GST_BUFFER_OFFSET_END_IS_VALID:
188 * @buffer: a #GstBuffer
190 * Tests if the end offset is known.
192 #define GST_BUFFER_OFFSET_END_IS_VALID(buffer) (GST_BUFFER_OFFSET_END (buffer) != GST_BUFFER_OFFSET_NONE)
194 * GST_BUFFER_IS_DISCONT:
195 * @buffer: a #GstBuffer
197 * Tests if the buffer marks a discontinuity in the stream.
201 #define GST_BUFFER_IS_DISCONT(buffer) (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
205 * @GST_BUFFER_FLAG_READONLY: the buffer is read-only. This means the data of
206 * the buffer should not be modified. The metadata might still be modified.
207 * @GST_BUFFER_FLAG_PREROLL: the buffer is part of a preroll and should not be
209 * @GST_BUFFER_FLAG_DISCONT: the buffer marks a discontinuity in the stream.
210 * This typically occurs after a seek or a dropped buffer from a live or
212 * @GST_BUFFER_FLAG_IN_CAPS: the buffer has been added as a field in a #GstCaps.
213 * @GST_BUFFER_FLAG_GAP: the buffer has been created to fill a gap in the
214 * stream and contains media neutral data (elements can switch to optimized code
215 * path that ignores the buffer content).
216 * @GST_BUFFER_FLAG_DELTA_UNIT: this unit cannot be decoded independently.
217 * @GST_BUFFER_FLAG_MEDIA1: a flag whose use is specific to the caps of the buffer. Since: 0.10.23.
218 * @GST_BUFFER_FLAG_MEDIA2: a flag whose use is specific to the caps of the buffer. Since: 0.10.23.
219 * @GST_BUFFER_FLAG_MEDIA3: a flag whose use is specific to the caps of the buffer. Since: 0.10.23.
220 * @GST_BUFFER_FLAG_LAST: additional flags can be added starting from this flag.
222 * A set of buffer flags used to describe properties of a #GstBuffer.
225 GST_BUFFER_FLAG_READONLY = GST_MINI_OBJECT_FLAG_READONLY,
226 GST_BUFFER_FLAG_PREROLL = (GST_MINI_OBJECT_FLAG_LAST << 0),
227 GST_BUFFER_FLAG_DISCONT = (GST_MINI_OBJECT_FLAG_LAST << 1),
228 GST_BUFFER_FLAG_IN_CAPS = (GST_MINI_OBJECT_FLAG_LAST << 2),
229 GST_BUFFER_FLAG_GAP = (GST_MINI_OBJECT_FLAG_LAST << 3),
230 GST_BUFFER_FLAG_DELTA_UNIT = (GST_MINI_OBJECT_FLAG_LAST << 4),
231 GST_BUFFER_FLAG_MEDIA1 = (GST_MINI_OBJECT_FLAG_LAST << 5),
232 GST_BUFFER_FLAG_MEDIA2 = (GST_MINI_OBJECT_FLAG_LAST << 6),
233 GST_BUFFER_FLAG_MEDIA3 = (GST_MINI_OBJECT_FLAG_LAST << 7),
234 GST_BUFFER_FLAG_LAST = (GST_MINI_OBJECT_FLAG_LAST << 8)
239 * @mini_object: the parent structure
240 * @data: pointer to the buffer data
241 * @size: size of buffer data
242 * @timestamp: timestamp of the buffer, can be #GST_CLOCK_TIME_NONE when the
243 * timestamp is not known or relevant.
244 * @duration: duration in time of the buffer data, can be #GST_CLOCK_TIME_NONE
245 * when the duration is not known or relevant.
246 * @caps: the #GstCaps describing the data format in this buffer
247 * @offset: a media specific offset for the buffer data.
248 * For video frames, this is the frame number of this buffer.
249 * For audio samples, this is the offset of the first sample in this buffer.
250 * For file data or compressed data this is the byte offset of the first
251 * byte in this buffer.
252 * @offset_end: the last offset contained in this buffer. It has the same
254 * @malloc_data: a pointer to the allocated memory associated with this buffer.
255 * When the buffer is freed, this data will freed with @free_func.
256 * @free_func: a custom function that will be called with @malloc_data, defaults
257 * to g_free(). Since 0.10.22.
258 * @parent: the parent buffer if this is a subbuffer. Since 0.10.26.
260 * The structure of a #GstBuffer. Use the associated macros to access the public
264 GstMiniObject mini_object;
266 /*< public >*/ /* with COW */
267 /* pointer to data and its size */
272 GstClockTime timestamp;
273 GstClockTime duration;
275 /* the media type of this buffer */
278 /* media specific offset */
289 gpointer _gst_reserved[GST_PADDING - 2];
292 struct _GstBufferClass {
293 GstMiniObjectClass mini_object_class;
296 GType gst_buffer_get_type (void);
299 GstBuffer * gst_buffer_new (void);
300 GstBuffer * gst_buffer_new_and_alloc (guint size);
301 GstBuffer * gst_buffer_try_new_and_alloc (guint size);
304 * gst_buffer_set_data:
306 * @data: The data (a #guint8 *) to set on the buffer.
307 * @size: The size (in bytes, as a #guint) of the data being set.
309 * A convenience function to set the data and size on a buffer.
310 * This will replace any existing data pointer set on this buffer, but will
311 * not change GST_BUFFER_MALLOCDATA(), if any. Callers should ensure that
312 * GST_BUFFER_MALLOCDATA() is non-NULL, or should free that and set it to NULL.
314 * No checks are done on the data or size arguments passed.
316 #define gst_buffer_set_data(buf, data, size) \
318 GST_BUFFER_DATA (buf) = data; \
319 GST_BUFFER_SIZE (buf) = size; \
325 * @buf: a #GstBuffer.
327 * Increases the refcount of the given buffer by one.
329 * Note that the refcount affects the writeability
330 * of @buf and its metadata, see gst_buffer_is_writable() and
331 * gst_buffer_is_metadata_writable(). It is
332 * important to note that keeping additional references to
333 * GstBuffer instances can potentially increase the number
334 * of memcpy operations in a pipeline.
338 #ifdef _FOOL_GTK_DOC_
339 G_INLINE_FUNC GstBuffer * gst_buffer_ref (GstBuffer * buf);
342 static inline GstBuffer *
343 gst_buffer_ref (GstBuffer * buf)
345 return (GstBuffer *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (buf));
350 * @buf: a #GstBuffer.
352 * Decreases the refcount of the buffer. If the refcount reaches 0, the buffer
353 * will be freed. If GST_BUFFER_MALLOCDATA() is non-NULL, this pointer will
354 * also be freed at this time.
356 #ifdef _FOOL_GTK_DOC_
357 G_INLINE_FUNC void gst_buffer_unref (GstBuffer * buf);
361 gst_buffer_unref (GstBuffer * buf)
363 gst_mini_object_unref (GST_MINI_OBJECT_CAST (buf));
369 * @buf: a #GstBuffer.
371 * Create a copy of the given buffer. This will also make a newly allocated
372 * copy of the data the source buffer contains.
374 * Returns: a new copy of @buf.
376 #ifdef _FOOL_GTK_DOC_
377 G_INLINE_FUNC GstBuffer * gst_buffer_copy (const GstBuffer * buf);
380 static inline GstBuffer *
381 gst_buffer_copy (const GstBuffer * buf)
383 return GST_BUFFER (gst_mini_object_copy (GST_MINI_OBJECT_CAST (buf)));
388 * GstBufferCopyFlags:
389 * @GST_BUFFER_COPY_FLAGS: flag indicating that buffer flags should be copied
390 * @GST_BUFFER_COPY_TIMESTAMPS: flag indicating that buffer timestamp, duration,
391 * offset and offset_end should be copied
392 * @GST_BUFFER_COPY_CAPS: flag indicating that buffer caps should be copied
394 * A set of flags that can be provided to the gst_buffer_copy_metadata()
395 * function to specify which metadata fields should be copied.
400 GST_BUFFER_COPY_FLAGS = (1 << 0),
401 GST_BUFFER_COPY_TIMESTAMPS = (1 << 1),
402 GST_BUFFER_COPY_CAPS = (1 << 2)
403 } GstBufferCopyFlags;
406 * GST_BUFFER_COPY_ALL:
408 * Combination of all possible fields that can be copied with
409 * gst_buffer_copy_metadata().
413 #define GST_BUFFER_COPY_ALL (GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS | GST_BUFFER_COPY_CAPS)
415 /* copies metadata into newly allocated buffer */
416 void gst_buffer_copy_metadata (GstBuffer *dest, const GstBuffer *src,
417 GstBufferCopyFlags flags);
420 * gst_buffer_is_writable:
423 * Tests if you can safely write data into a buffer's data array or validly
424 * modify the caps and timestamp metadata. Metadata in a GstBuffer is always
425 * writable, but it is only safe to change it when there is only one owner
426 * of the buffer - ie, the refcount is 1.
428 #define gst_buffer_is_writable(buf) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (buf))
430 * gst_buffer_make_writable:
433 * Makes a writable buffer from the given buffer. If the source buffer is
434 * already writable, this will simply return the same buffer. A copy will
435 * otherwise be made using gst_buffer_copy().
437 #define gst_buffer_make_writable(buf) GST_BUFFER_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (buf)))
439 /* Ensure that the metadata of the buffer is writable, even if the buffer data
441 gboolean gst_buffer_is_metadata_writable (GstBuffer *buf);
442 GstBuffer* gst_buffer_make_metadata_writable (GstBuffer *buf);
445 * gst_buffer_replace:
446 * @obuf: pointer to a pointer to a #GstBuffer to be replaced.
447 * @nbuf: pointer to a #GstBuffer that will replace the buffer pointed to by
450 * Modifies a pointer to a #GstBuffer to point to a different #GstBuffer. The
451 * modification is done atomically (so this is useful for ensuring thread safety
452 * in some cases), and the reference counts are updated appropriately (the old
453 * buffer is unreffed, the new is reffed).
455 * Either @nbuf or the #GstBuffer pointed to by @obuf may be NULL.
457 #define gst_buffer_replace(obuf,nbuf) \
459 GstBuffer **___obufaddr = (GstBuffer **)(obuf); \
460 gst_mini_object_replace ((GstMiniObject **)___obufaddr, \
461 GST_MINI_OBJECT_CAST (nbuf)); \
464 GstCaps* gst_buffer_get_caps (GstBuffer *buffer);
465 void gst_buffer_set_caps (GstBuffer *buffer, GstCaps *caps);
467 /* creating a subbuffer */
468 GstBuffer* gst_buffer_create_sub (GstBuffer *parent, guint offset, guint size);
470 /* span, two buffers, intelligently */
471 gboolean gst_buffer_is_span_fast (GstBuffer *buf1, GstBuffer *buf2);
472 GstBuffer* gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len);
475 * gst_value_set_buffer:
476 * @v: a #GValue to receive the data
477 * @b: a #GstBuffer to assign to the GstValue
479 * Sets @b as the value of @v. Caller retains reference to buffer.
481 #define gst_value_set_buffer(v,b) gst_value_set_mini_object(v, GST_MINI_OBJECT_CAST(b))
483 * gst_value_take_buffer:
484 * @v: a #GValue to receive the data
485 * @b: a #GstBuffer to assign to the GstValue
487 * Sets @b as the value of @v. Caller gives away reference to buffer.
489 #define gst_value_take_buffer(v,b) gst_value_take_mini_object(v, GST_MINI_OBJECT_CAST(b))
491 * gst_value_get_buffer:
492 * @v: a #GValue to query
494 * Receives a #GstBuffer as the value of @v. Does not return a reference to
495 * the buffer, so the pointer is only valid for as long as the caller owns
498 #define gst_value_get_buffer(v) GST_BUFFER_CAST (gst_value_get_mini_object(v))
502 #endif /* __GST_BUFFER_H__ */