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)
146 * GST_BUFFER_OFFSET_NONE:
148 * Constant for no-offset return results.
150 #define GST_BUFFER_OFFSET_NONE ((guint64)-1)
153 * GST_BUFFER_DURATION_IS_VALID:
154 * @buffer: a #GstBuffer
156 * Tests if the duration is known.
158 #define GST_BUFFER_DURATION_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer)))
160 * GST_BUFFER_TIMESTAMP_IS_VALID:
161 * @buffer: a #GstBuffer
163 * Tests if the timestamp is known.
165 #define GST_BUFFER_TIMESTAMP_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buffer)))
167 * GST_BUFFER_OFFSET_IS_VALID:
168 * @buffer: a #GstBuffer
170 * Tests if the start offset is known.
172 #define GST_BUFFER_OFFSET_IS_VALID(buffer) (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE)
174 * GST_BUFFER_OFFSET_END_IS_VALID:
175 * @buffer: a #GstBuffer
177 * Tests if the end offset is known.
179 #define GST_BUFFER_OFFSET_END_IS_VALID(buffer) (GST_BUFFER_OFFSET_END (buffer) != GST_BUFFER_OFFSET_NONE)
181 * GST_BUFFER_IS_DISCONT:
182 * @buffer: a #GstBuffer
184 * Tests if the buffer marks a discontinuity in the stream.
188 #define GST_BUFFER_IS_DISCONT(buffer) (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
192 * @GST_BUFFER_FLAG_READONLY: the buffer is read-only. This means the data of
193 * the buffer should not be modified. The metadata might still be modified.
194 * @GST_BUFFER_FLAG_PREROLL: the buffer is part of a preroll and should not be
196 * @GST_BUFFER_FLAG_DISCONT: the buffer marks a discontinuity in the stream.
197 * This typically occurs after a seek or a dropped buffer from a live or
199 * @GST_BUFFER_FLAG_IN_CAPS: the buffer has been added as a field in a #GstCaps.
200 * @GST_BUFFER_FLAG_GAP: the buffer has been created to fill a gap in the
201 * stream and contains media neutral data (elements can switch to optimized code
202 * path that ignores the buffer content).
203 * @GST_BUFFER_FLAG_DELTA_UNIT: this unit cannot be decoded independently.
204 * @GST_BUFFER_FLAG_LAST: additional flags can be added starting from this flag.
206 * A set of buffer flags used to describe properties of a #GstBuffer.
209 GST_BUFFER_FLAG_READONLY = GST_MINI_OBJECT_FLAG_READONLY,
210 GST_BUFFER_FLAG_PREROLL = (GST_MINI_OBJECT_FLAG_LAST << 0),
211 GST_BUFFER_FLAG_DISCONT = (GST_MINI_OBJECT_FLAG_LAST << 1),
212 GST_BUFFER_FLAG_IN_CAPS = (GST_MINI_OBJECT_FLAG_LAST << 2),
213 GST_BUFFER_FLAG_GAP = (GST_MINI_OBJECT_FLAG_LAST << 3),
214 GST_BUFFER_FLAG_DELTA_UNIT = (GST_MINI_OBJECT_FLAG_LAST << 4),
216 GST_BUFFER_FLAG_LAST = (GST_MINI_OBJECT_FLAG_LAST << 8)
221 * @mini_object: the parent structure
222 * @data: pointer to the buffer data
223 * @size: size of buffer data
224 * @timestamp: timestamp of the buffer, can be #GST_CLOCK_TIME_NONE when the
225 * timestamp is not known or relevant.
226 * @duration: duration in time of the buffer data, can be #GST_CLOCK_TIME_NONE
227 * when the duration is not known or relevant.
228 * @caps: the #GstCaps describing the data format in this buffer
229 * @offset: a media specific offset for the buffer data.
230 * For video frames, this is the frame number of this buffer.
231 * For audio samples, this is the offset of the first sample in this buffer.
232 * For file data or compressed data this is the byte offset of the first
233 * byte in this buffer.
234 * @offset_end: the last offset contained in this buffer. It has the same
236 * @malloc_data: a pointer to the allocated memory associated with this buffer.
237 * When the buffer is freed, this data will freed with g_free().
239 * The structure of a #GstBuffer. Use the associated macros to access the public
243 GstMiniObject mini_object;
245 /*< public >*/ /* with COW */
246 /* pointer to data and its size */
251 GstClockTime timestamp;
252 GstClockTime duration;
254 /* the media type of this buffer */
257 /* media specific offset */
264 gpointer _gst_reserved[GST_PADDING];
267 struct _GstBufferClass {
268 GstMiniObjectClass mini_object_class;
271 GType gst_buffer_get_type (void);
274 GstBuffer * gst_buffer_new (void);
275 GstBuffer * gst_buffer_new_and_alloc (guint size);
276 GstBuffer * gst_buffer_try_new_and_alloc (guint size);
279 * gst_buffer_set_data:
281 * @data: The data (a #guint8 *) to set on the buffer.
282 * @size: The size (in bytes, as a #guint) of the data being set.
284 * A convenience function to set the data and size on a buffer.
285 * This will replace any existing data pointer set on this buffer, but will
286 * not change GST_BUFFER_MALLOCDATA(), if any. Callers should ensure that
287 * GST_BUFFER_MALLOCDATA() is non-NULL, or should free that and set it to NULL.
289 * No checks are done on the data or size arguments passed.
291 #define gst_buffer_set_data(buf, data, size) \
293 GST_BUFFER_DATA (buf) = data; \
294 GST_BUFFER_SIZE (buf) = size; \
300 * @buf: a #GstBuffer.
302 * Increases the refcount of the given buffer by one.
304 * Note that the refcount affects the writeability
305 * of @buf and its metadata, see gst_buffer_is_writable() and
306 * gst_buffer_is_metadata_writable(). It is
307 * important to note that keeping additional references to
308 * GstBuffer instances can potentially increase the number
309 * of memcpy operations in a pipeline.
313 #ifdef _FOOL_GTK_DOC_
314 G_INLINE_FUNC GstBuffer * gst_buffer_ref (GstBuffer * buf);
317 static inline GstBuffer *
318 gst_buffer_ref (GstBuffer * buf)
320 /* not using a macro here because gcc-4.1 will complain
321 * if the return value isn't used (because of the cast) */
322 return (GstBuffer *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (buf));
327 * @buf: a #GstBuffer.
329 * Decreases the refcount of the buffer. If the refcount reaches 0, the buffer
330 * will be freed. If GST_BUFFER_MALLOCDATA() is non-NULL, this pointer will
331 * also be freed at this time.
333 #define gst_buffer_unref(buf) gst_mini_object_unref (GST_MINI_OBJECT_CAST (buf))
338 * @buf: a #GstBuffer.
340 * Create a copy of the given buffer. This will also make a newly allocated
341 * copy of the data the source buffer contains.
343 #define gst_buffer_copy(buf) GST_BUFFER_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CAST (buf)))
346 * GstBufferCopyFlags:
347 * @GST_BUFFER_COPY_FLAGS: flag indicating that buffer flags should be copied
348 * @GST_BUFFER_COPY_TIMESTAMPS: flag indicating that buffer timestamp, duration,
349 * offset and offset_end should be copied
350 * @GST_BUFFER_COPY_CAPS: flag indicating that buffer caps should be copied
352 * A set of flags that can be provided to the gst_buffer_copy_metadata()
353 * function to specify which metadata fields should be copied.
358 GST_BUFFER_COPY_FLAGS = (1 << 0),
359 GST_BUFFER_COPY_TIMESTAMPS = (1 << 1),
360 GST_BUFFER_COPY_CAPS = (1 << 2)
361 } GstBufferCopyFlags;
364 * GST_BUFFER_COPY_ALL:
366 * Combination of all possible fields that can be copied with
367 * gst_buffer_copy_metadata().
371 #define GST_BUFFER_COPY_ALL (GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS | GST_BUFFER_COPY_CAPS)
373 /* copies metadata into newly allocated buffer */
374 void gst_buffer_copy_metadata (GstBuffer *dest, const GstBuffer *src,
375 GstBufferCopyFlags flags);
378 * gst_buffer_is_writable:
381 * Tests if you can safely write data into a buffer's data array or validly
382 * modify the caps and timestamp metadata. Metadata in a GstBuffer is always
383 * writable, but it is only safe to change it when there is only one owner
384 * of the buffer - ie, the refcount is 1.
386 #define gst_buffer_is_writable(buf) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (buf))
388 * gst_buffer_make_writable:
391 * Makes a writable buffer from the given buffer. If the source buffer is
392 * already writable, this will simply return the same buffer. A copy will
393 * otherwise be made using gst_buffer_copy().
395 #define gst_buffer_make_writable(buf) GST_BUFFER_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (buf)))
397 /* Ensure that the metadata of the buffer is writable, even if the buffer data
399 gboolean gst_buffer_is_metadata_writable (GstBuffer *buf);
400 GstBuffer* gst_buffer_make_metadata_writable (GstBuffer *buf);
403 * gst_buffer_replace:
404 * @obuf: pointer to a pointer to a #GstBuffer to be replaced.
405 * @nbuf: pointer to a #GstBuffer that will replace the buffer pointed to by
408 * Modifies a pointer to a #Gstbuffer to point to a different #GstBuffer. The
409 * modification is done atomically (so this is useful for ensuring thread safety
410 * in some cases), and the reference counts are updated appropriately (the old
411 * buffer is unreffed, the new is reffed).
413 * Either @nbuf or the #GstBuffer pointed to by @obuf may be NULL.
415 #define gst_buffer_replace(obuf,nbuf) \
417 GstBuffer **___obufaddr = (GstBuffer **)(obuf); \
418 gst_mini_object_replace ((GstMiniObject **)___obufaddr, \
419 GST_MINI_OBJECT_CAST (nbuf)); \
422 GstCaps* gst_buffer_get_caps (GstBuffer *buffer);
423 void gst_buffer_set_caps (GstBuffer *buffer, GstCaps *caps);
425 /* creating a subbuffer */
426 GstBuffer* gst_buffer_create_sub (GstBuffer *parent, guint offset, guint size);
428 /* span, two buffers, intelligently */
429 gboolean gst_buffer_is_span_fast (GstBuffer *buf1, GstBuffer *buf2);
430 GstBuffer* gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len);
433 * gst_value_set_buffer:
434 * @v: a #GstValue to receive the data
435 * @b: a #GstBuffer to assign to the GstValue
437 * Sets @b as the value of @v. Caller retains reference to buffer.
439 #define gst_value_set_buffer(v,b) gst_value_set_mini_object(v, GST_MINI_OBJECT_CAST(b))
441 * gst_value_take_buffer:
442 * @v: a #GstValue to receive the data
443 * @b: a #GstBuffer to assign to the GstValue
445 * Sets @b as the value of @v. Caller gives away reference to buffer.
447 #define gst_value_take_buffer(v,b) gst_value_take_mini_object(v, GST_MINI_OBJECT_CAST(b))
449 * gst_value_get_buffer:
450 * @v: a #GstValue to qeury
452 * Receives a #GstBuffer as the value of @v. Does not return a reference to
453 * the buffer, so the pointer is only valid for as long as the caller owns
456 #define gst_value_get_buffer(v) GST_BUFFER_CAST (gst_value_get_mini_object(v))
460 #endif /* __GST_BUFFER_H__ */