1 /* GStreamer
2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
4 *
5 * gstbuffer.h: Header for GstBuffer object
6 *
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.
11 *
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.
16 *
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.
21 */
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>
31 G_BEGIN_DECLS
33 typedef struct _GstBuffer GstBuffer;
34 typedef struct _GstBufferClass GstBufferClass;
35 typedef struct _GstBufferPrivate GstBufferPrivate;
37 /**
38 * GST_BUFFER_TRACE_NAME:
39 *
40 * The name used for tracing memory allocations.
41 */
42 #define GST_BUFFER_TRACE_NAME "GstBuffer"
44 #define GST_TYPE_BUFFER (gst_buffer_get_type())
45 #define GST_IS_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_BUFFER))
46 #define GST_IS_BUFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_BUFFER))
47 #define GST_BUFFER_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BUFFER, GstBufferClass))
48 #define GST_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_BUFFER, GstBuffer))
49 #define GST_BUFFER_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_BUFFER, GstBufferClass))
50 #define GST_BUFFER_CAST(obj) ((GstBuffer *)(obj))
52 /**
53 * GST_BUFFER_FLAGS:
54 * @buf: a #GstBuffer.
55 *
56 * A flags word containing #GstBufferFlag flags set on this buffer.
57 */
58 #define GST_BUFFER_FLAGS(buf) GST_MINI_OBJECT_FLAGS(buf)
59 /**
60 * GST_BUFFER_FLAG_IS_SET:
61 * @buf: a #GstBuffer.
62 * @flag: the #GstBufferFlag to check.
63 *
64 * Gives the status of a specific flag on a buffer.
65 */
66 #define GST_BUFFER_FLAG_IS_SET(buf,flag) GST_MINI_OBJECT_FLAG_IS_SET (buf, flag)
67 /**
68 * GST_BUFFER_FLAG_SET:
69 * @buf: a #GstBuffer.
70 * @flag: the #GstBufferFlag to set.
71 *
72 * Sets a buffer flag on a buffer.
73 */
74 #define GST_BUFFER_FLAG_SET(buf,flag) GST_MINI_OBJECT_FLAG_SET (buf, flag)
75 /**
76 * GST_BUFFER_FLAG_UNSET:
77 * @buf: a #GstBuffer.
78 * @flag: the #GstBufferFlag to clear.
79 *
80 * Clears a buffer flag.
81 */
82 #define GST_BUFFER_FLAG_UNSET(buf,flag) GST_MINI_OBJECT_FLAG_UNSET (buf, flag)
84 /**
85 * GST_BUFFER_DATA:
86 * @buf: a #GstBuffer.
87 *
88 * A pointer to the data element of this buffer.
89 */
90 #define GST_BUFFER_DATA(buf) (GST_BUFFER_CAST(buf)->data)
91 /**
92 * GST_BUFFER_SIZE:
93 * @buf: a #GstBuffer.
94 *
95 * The size in bytes of the data in this buffer.
96 */
97 #define GST_BUFFER_SIZE(buf) (GST_BUFFER_CAST(buf)->size)
98 /**
99 * GST_BUFFER_TIMESTAMP:
100 * @buf: a #GstBuffer.:
101 *
102 * The timestamp in nanoseconds (as a #GstClockTime) of the data in the buffer.
103 * Value will be %GST_CLOCK_TIME_NONE if the timestamp is unknown.
104 *
105 */
106 #define GST_BUFFER_TIMESTAMP(buf) (GST_BUFFER_CAST(buf)->timestamp)
107 /**
108 * GST_BUFFER_DURATION:
109 * @buf: a #GstBuffer.
110 *
111 * The duration in nanoseconds (as a #GstClockTime) of the data in the buffer.
112 * Value will be %GST_CLOCK_TIME_NONE if the duration is unknown.
113 */
114 #define GST_BUFFER_DURATION(buf) (GST_BUFFER_CAST(buf)->duration)
115 /**
116 * GST_BUFFER_CAPS:
117 * @buf: a #GstBuffer.
118 *
119 * The caps for this buffer.
120 */
121 #define GST_BUFFER_CAPS(buf) (GST_BUFFER_CAST(buf)->caps)
122 /**
123 * GST_BUFFER_OFFSET:
124 * @buf: a #GstBuffer.
125 *
126 * The offset in the source file of the beginning of this buffer.
127 */
128 #define GST_BUFFER_OFFSET(buf) (GST_BUFFER_CAST(buf)->offset)
129 /**
130 * GST_BUFFER_OFFSET_END:
131 * @buf: a #GstBuffer.
132 *
133 * The offset in the source file of the end of this buffer.
134 */
135 #define GST_BUFFER_OFFSET_END(buf) (GST_BUFFER_CAST(buf)->offset_end)
136 /**
137 * GST_BUFFER_MALLOCDATA:
138 * @buf: a #GstBuffer.
139 *
140 * A pointer to any data allocated for this buffer using g_malloc(). If this is
141 * non-NULL, this memory will be freed at the end of the buffer's lifecycle
142 * (i.e. when its refcount becomes zero).
143 */
144 #define GST_BUFFER_MALLOCDATA(buf) (GST_BUFFER_CAST(buf)->malloc_data)
145 /**
146 * GST_BUFFER_FREE_FUNC:
147 * @buf: a #GstBuffer.
148 *
149 * A pointer to a function that will be called on the buffer's malloc_data when
150 * this buffer is finalized. Defaults to g_free().
151 *
152 * Note that the free function only affects the buffer's malloc_data; if the
153 * buffer's malloc_data is %NULL, the function will not be called.
154 *
155 * Since: 0.10.22
156 */
157 #define GST_BUFFER_FREE_FUNC(buf) (GST_BUFFER_CAST(buf)->free_func)
159 /**
160 * GST_BUFFER_OFFSET_NONE:
161 *
162 * Constant for no-offset return results.
163 */
164 #define GST_BUFFER_OFFSET_NONE ((guint64)-1)
166 /**
167 * GST_BUFFER_DURATION_IS_VALID:
168 * @buffer: a #GstBuffer
169 *
170 * Tests if the duration is known.
171 */
172 #define GST_BUFFER_DURATION_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer)))
173 /**
174 * GST_BUFFER_TIMESTAMP_IS_VALID:
175 * @buffer: a #GstBuffer
176 *
177 * Tests if the timestamp is known.
178 */
179 #define GST_BUFFER_TIMESTAMP_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buffer)))
180 /**
181 * GST_BUFFER_OFFSET_IS_VALID:
182 * @buffer: a #GstBuffer
183 *
184 * Tests if the start offset is known.
185 */
186 #define GST_BUFFER_OFFSET_IS_VALID(buffer) (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE)
187 /**
188 * GST_BUFFER_OFFSET_END_IS_VALID:
189 * @buffer: a #GstBuffer
190 *
191 * Tests if the end offset is known.
192 */
193 #define GST_BUFFER_OFFSET_END_IS_VALID(buffer) (GST_BUFFER_OFFSET_END (buffer) != GST_BUFFER_OFFSET_NONE)
194 /**
195 * GST_BUFFER_IS_DISCONT:
196 * @buffer: a #GstBuffer
197 *
198 * Tests if the buffer marks a discontinuity in the stream.
199 *
200 * Since: 0.10.9
201 */
202 #define GST_BUFFER_IS_DISCONT(buffer) (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
204 /**
205 * GstBufferFlag:
206 * @GST_BUFFER_FLAG_READONLY: the buffer is read-only. This means the data of
207 * the buffer should not be modified. The metadata might still be modified.
208 * @GST_BUFFER_FLAG_PREROLL: the buffer is part of a preroll and should not be
209 * displayed.
210 * @GST_BUFFER_FLAG_DISCONT: the buffer marks a discontinuity in the stream.
211 * This typically occurs after a seek or a dropped buffer from a live or
212 * network source.
213 * @GST_BUFFER_FLAG_IN_CAPS: the buffer has been added as a field in a #GstCaps.
214 * @GST_BUFFER_FLAG_GAP: the buffer has been created to fill a gap in the
215 * stream and contains media neutral data (elements can switch to optimized code
216 * path that ignores the buffer content).
217 * @GST_BUFFER_FLAG_DELTA_UNIT: this unit cannot be decoded independently.
218 * @GST_BUFFER_FLAG_MEDIA1: a flag whose use is specific to the caps of the buffer. Since: 0.10.23.
219 * @GST_BUFFER_FLAG_MEDIA2: a flag whose use is specific to the caps of the buffer. Since: 0.10.23.
220 * @GST_BUFFER_FLAG_MEDIA3: a flag whose use is specific to the caps of the buffer. Since: 0.10.23.
221 * @GST_BUFFER_FLAG_MEDIA4: a flag whose use is specific to the caps of the buffer. Since: 0.10.33.
222 * @GST_BUFFER_FLAG_LAST: additional flags can be added starting from this flag.
223 *
224 * A set of buffer flags used to describe properties of a #GstBuffer.
225 */
226 typedef enum {
227 GST_BUFFER_FLAG_READONLY = GST_MINI_OBJECT_FLAG_READONLY,
228 GST_BUFFER_FLAG_MEDIA4 = GST_MINI_OBJECT_FLAG_RESERVED1,
229 GST_BUFFER_FLAG_PREROLL = (GST_MINI_OBJECT_FLAG_LAST << 0),
230 GST_BUFFER_FLAG_DISCONT = (GST_MINI_OBJECT_FLAG_LAST << 1),
231 GST_BUFFER_FLAG_IN_CAPS = (GST_MINI_OBJECT_FLAG_LAST << 2),
232 GST_BUFFER_FLAG_GAP = (GST_MINI_OBJECT_FLAG_LAST << 3),
233 GST_BUFFER_FLAG_DELTA_UNIT = (GST_MINI_OBJECT_FLAG_LAST << 4),
234 GST_BUFFER_FLAG_MEDIA1 = (GST_MINI_OBJECT_FLAG_LAST << 5),
235 GST_BUFFER_FLAG_MEDIA2 = (GST_MINI_OBJECT_FLAG_LAST << 6),
236 GST_BUFFER_FLAG_MEDIA3 = (GST_MINI_OBJECT_FLAG_LAST << 7),
237 GST_BUFFER_FLAG_LAST = (GST_MINI_OBJECT_FLAG_LAST << 8)
238 } GstBufferFlag;
240 /**
241 * GstBuffer:
242 * @mini_object: the parent structure
243 * @data: pointer to the buffer data
244 * @size: size of buffer data
245 * @timestamp: timestamp of the buffer, can be #GST_CLOCK_TIME_NONE when the
246 * timestamp is not known or relevant.
247 * @duration: duration in time of the buffer data, can be #GST_CLOCK_TIME_NONE
248 * when the duration is not known or relevant.
249 * @caps: the #GstCaps describing the data format in this buffer
250 * @offset: a media specific offset for the buffer data.
251 * For video frames, this is the frame number of this buffer.
252 * For audio samples, this is the offset of the first sample in this buffer.
253 * For file data or compressed data this is the byte offset of the first
254 * byte in this buffer.
255 * @offset_end: the last offset contained in this buffer. It has the same
256 * format as @offset.
257 * @malloc_data: a pointer to the allocated memory associated with this buffer.
258 * When the buffer is freed, this data will freed with @free_func.
259 * @free_func: a custom function that will be called with @malloc_data, defaults
260 * to g_free(). Since 0.10.22.
261 * @parent: the parent buffer if this is a subbuffer. Since 0.10.26.
262 *
263 * The structure of a #GstBuffer. Use the associated macros to access the public
264 * variables.
265 */
266 struct _GstBuffer {
267 GstMiniObject mini_object;
269 /*< public >*/ /* with COW */
270 /* pointer to data and its size */
271 guint8 *data;
272 guint size;
274 /* timestamp */
275 GstClockTime timestamp;
276 GstClockTime duration;
278 /* the media type of this buffer */
279 GstCaps *caps;
281 /* media specific offset */
282 guint64 offset;
283 guint64 offset_end;
285 guint8 *malloc_data;
287 /* ABI Added */
288 GFreeFunc free_func;
289 GstBuffer *parent;
291 /*< private >*/
292 GstBufferPrivate *priv;
293 gpointer _gst_reserved[GST_PADDING - 3];
294 };
296 struct _GstBufferClass {
297 GstMiniObjectClass mini_object_class;
298 };
300 GType gst_buffer_get_type (void);
302 /* allocation */
303 GstBuffer * gst_buffer_new (void) G_GNUC_MALLOC;
304 GstBuffer * gst_buffer_new_and_alloc (guint size) G_GNUC_MALLOC;
305 GstBuffer * gst_buffer_try_new_and_alloc (guint size) G_GNUC_MALLOC;
307 /**
308 * gst_buffer_set_data:
309 * @buf: a #GstBuffer
310 * @data: The data (a #guint8 *) to set on the buffer.
311 * @size: The size (in bytes, as a #guint) of the data being set.
312 *
313 * A convenience function to set the data and size on a buffer.
314 * This will replace any existing data pointer set on this buffer, but will
315 * not change GST_BUFFER_MALLOCDATA(), if any. Callers should ensure that
316 * GST_BUFFER_MALLOCDATA() is non-NULL, or should free that and set it to NULL.
317 *
318 * No checks are done on the data or size arguments passed.
319 */
320 #define gst_buffer_set_data(buf, data, size) \
321 G_STMT_START { \
322 GST_BUFFER_DATA (buf) = data; \
323 GST_BUFFER_SIZE (buf) = size; \
324 } G_STMT_END
326 /* refcounting */
327 /**
328 * gst_buffer_ref:
329 * @buf: a #GstBuffer.
330 *
331 * Increases the refcount of the given buffer by one.
332 *
333 * Note that the refcount affects the writeability
334 * of @buf and its metadata, see gst_buffer_is_writable() and
335 * gst_buffer_is_metadata_writable(). It is
336 * important to note that keeping additional references to
337 * GstBuffer instances can potentially increase the number
338 * of memcpy operations in a pipeline.
339 *
340 * Returns: (transfer full): @buf
341 */
342 #ifdef _FOOL_GTK_DOC_
343 G_INLINE_FUNC GstBuffer * gst_buffer_ref (GstBuffer * buf);
344 #endif
346 static inline GstBuffer *
347 gst_buffer_ref (GstBuffer * buf)
348 {
349 return (GstBuffer *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (buf));
350 }
352 /**
353 * gst_buffer_unref:
354 * @buf: (transfer full): a #GstBuffer.
355 *
356 * Decreases the refcount of the buffer. If the refcount reaches 0, the buffer
357 * will be freed. If GST_BUFFER_MALLOCDATA() is non-NULL, this pointer will
358 * also be freed at this time.
359 */
360 #ifdef _FOOL_GTK_DOC_
361 G_INLINE_FUNC void gst_buffer_unref (GstBuffer * buf);
362 #endif
364 static inline void
365 gst_buffer_unref (GstBuffer * buf)
366 {
367 gst_mini_object_unref (GST_MINI_OBJECT_CAST (buf));
368 }
370 /* copy buffer */
371 /**
372 * gst_buffer_copy:
373 * @buf: a #GstBuffer.
374 *
375 * Create a copy of the given buffer. This will also make a newly allocated
376 * copy of the data the source buffer contains.
377 *
378 * Returns: (transfer full): a new copy of @buf.
379 */
380 #ifdef _FOOL_GTK_DOC_
381 G_INLINE_FUNC GstBuffer * gst_buffer_copy (const GstBuffer * buf);
382 #endif
384 static inline GstBuffer *
385 gst_buffer_copy (const GstBuffer * buf)
386 {
387 return GST_BUFFER (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (buf)));
388 }
391 /**
392 * GstBufferCopyFlags:
393 * @GST_BUFFER_COPY_FLAGS: flag indicating that buffer flags should be copied
394 * @GST_BUFFER_COPY_TIMESTAMPS: flag indicating that buffer timestamp, duration,
395 * offset and offset_end should be copied
396 * @GST_BUFFER_COPY_CAPS: flag indicating that buffer caps should be copied
397 * @GST_BUFFER_COPY_QDATA: flag indicating that buffer qdata should be copied
398 * (Since 0.10.36)
399 *
400 * A set of flags that can be provided to the gst_buffer_copy_metadata()
401 * function to specify which metadata fields should be copied.
402 *
403 * Since: 0.10.13
404 */
405 typedef enum {
406 GST_BUFFER_COPY_FLAGS = (1 << 0),
407 GST_BUFFER_COPY_TIMESTAMPS = (1 << 1),
408 GST_BUFFER_COPY_CAPS = (1 << 2),
409 GST_BUFFER_COPY_QDATA = (1 << 3)
410 } GstBufferCopyFlags;
412 /**
413 * GST_BUFFER_COPY_ALL:
414 *
415 * Combination of all possible fields that can be copied with
416 * gst_buffer_copy_metadata().
417 *
418 * Since: 0.10.13
419 */
420 #define GST_BUFFER_COPY_ALL ((GstBufferCopyFlags) (GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS | GST_BUFFER_COPY_CAPS | GST_BUFFER_COPY_QDATA))
422 /* copies metadata into newly allocated buffer */
423 void gst_buffer_copy_metadata (GstBuffer *dest, const GstBuffer *src,
424 GstBufferCopyFlags flags);
426 /**
427 * gst_buffer_is_writable:
428 * @buf: a #GstBuffer
429 *
430 * Tests if you can safely write data into a buffer's data array or validly
431 * modify the caps and timestamp metadata. Metadata in a GstBuffer is always
432 * writable, but it is only safe to change it when there is only one owner
433 * of the buffer - ie, the refcount is 1.
434 */
435 #define gst_buffer_is_writable(buf) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (buf))
436 /**
437 * gst_buffer_make_writable:
438 * @buf: (transfer full): a #GstBuffer
439 *
440 * Makes a writable buffer from the given buffer. If the source buffer is
441 * already writable, this will simply return the same buffer. A copy will
442 * otherwise be made using gst_buffer_copy().
443 *
444 * Returns: (transfer full): a writable buffer which may or may not be the
445 * same as @buf
446 */
447 #define gst_buffer_make_writable(buf) GST_BUFFER_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_CAST (buf)))
449 /* Ensure that the metadata of the buffer is writable, even if the buffer data
450 * isn't */
451 gboolean gst_buffer_is_metadata_writable (GstBuffer *buf);
452 GstBuffer* gst_buffer_make_metadata_writable (GstBuffer *buf);
454 /* per-buffer user data */
456 void gst_buffer_set_qdata (GstBuffer * buffer,
457 GQuark quark,
458 GstStructure * data);
460 const GstStructure * gst_buffer_get_qdata (GstBuffer * buffer,
461 GQuark quark);
465 /**
466 * gst_buffer_replace:
467 * @obuf: (inout) (transfer full): pointer to a pointer to a #GstBuffer to be
468 * replaced.
469 * @nbuf: (transfer none) (allow-none): pointer to a #GstBuffer that will
470 * replace the buffer pointed to by @obuf.
471 *
472 * Modifies a pointer to a #GstBuffer to point to a different #GstBuffer. The
473 * modification is done atomically (so this is useful for ensuring thread safety
474 * in some cases), and the reference counts are updated appropriately (the old
475 * buffer is unreffed, the new is reffed).
476 *
477 * Either @nbuf or the #GstBuffer pointed to by @obuf may be NULL.
478 */
479 #ifdef _FOOL_GTK_DOC_
480 G_INLINE_FUNC void gst_buffer_replace (GstBuffer **obuf, GstBuffer *nbuf);
481 #endif
483 static inline void
484 gst_buffer_replace (GstBuffer **obuf, GstBuffer *nbuf)
485 {
486 gst_mini_object_replace ((GstMiniObject **) obuf, (GstMiniObject *) nbuf);
487 }
489 GstCaps* gst_buffer_get_caps (GstBuffer *buffer);
490 void gst_buffer_set_caps (GstBuffer *buffer, GstCaps *caps);
492 /* creating a subbuffer */
493 GstBuffer* gst_buffer_create_sub (GstBuffer *parent, guint offset, guint size) G_GNUC_MALLOC;
495 /* span, two buffers, intelligently */
496 gboolean gst_buffer_is_span_fast (GstBuffer *buf1, GstBuffer *buf2);
497 GstBuffer* gst_buffer_span (GstBuffer *buf1, guint32 offset, GstBuffer *buf2, guint32 len) G_GNUC_MALLOC;
499 /**
500 * gst_value_set_buffer:
501 * @v: a #GValue to receive the data
502 * @b: (transfer none): a #GstBuffer to assign to the GstValue
503 *
504 * Sets @b as the value of @v. Caller retains reference to buffer.
505 */
506 #define gst_value_set_buffer(v,b) gst_value_set_mini_object(v, GST_MINI_OBJECT_CAST(b))
507 /**
508 * gst_value_take_buffer:
509 * @v: a #GValue to receive the data
510 * @b: (transfer full): a #GstBuffer to assign to the GstValue
511 *
512 * Sets @b as the value of @v. Caller gives away reference to buffer.
513 */
514 #define gst_value_take_buffer(v,b) gst_value_take_mini_object(v, GST_MINI_OBJECT_CAST(b))
515 /**
516 * gst_value_get_buffer:
517 * @v: a #GValue to query
518 *
519 * Receives a #GstBuffer as the value of @v. Does not return a reference to
520 * the buffer, so the pointer is only valid for as long as the caller owns
521 * a reference to @v.
522 *
523 * Returns: (transfer none): buffer
524 */
525 #define gst_value_get_buffer(v) GST_BUFFER_CAST (gst_value_get_mini_object(v))
527 G_END_DECLS
529 #endif /* __GST_BUFFER_H__ */