2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstbuffer.c: Buffer operations
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.
25 * @short_description: Data-passing buffer type, supporting sub-buffers.
26 * @see_also: #GstPad, #GstMiniObject
28 * Buffers are the basic unit of data transfer in GStreamer. The #GstBuffer
29 * type provides all the state necessary to define a region of memory as part
30 * of a stream. Sub-buffers are also supported, allowing a smaller region of a
31 * buffer to become its own buffer, with mechanisms in place to ensure that
32 * neither memory space goes away prematurely.
34 * Buffers are usually created with gst_buffer_new(). After a buffer has been
35 * created one will typically allocate memory for it and set the size of the
36 * buffer data. The following example creates a buffer that can hold a given
37 * video frame with a given width, height and bits per plane.
39 * <title>Creating a buffer for a video frame</title>
42 * gint size, width, height, bpp;
44 * size = width * height * bpp;
45 * buffer = gst_buffer_new ();
46 * GST_BUFFER_SIZE (buffer) = size;
47 * GST_BUFFER_MALLOCDATA (buffer) = g_malloc (size);
48 * GST_BUFFER_DATA (buffer) = GST_BUFFER_MALLOCDATA (buffer);
53 * Alternatively, use gst_buffer_new_and_alloc()
54 * to create a buffer with preallocated data of a given size.
56 * The data pointed to by the buffer can be retrieved with the GST_BUFFER_DATA()
57 * macro. The size of the data can be found with GST_BUFFER_SIZE(). For buffers
58 * of size 0, the data pointer is undefined (usually NULL) and should never be used.
60 * If an element knows what pad you will push the buffer out on, it should use
61 * gst_pad_alloc_buffer() instead to create a buffer. This allows downstream
62 * elements to provide special buffers to write in, like hardware buffers.
64 * A buffer has a pointer to a #GstCaps describing the media type of the data
65 * in the buffer. Attach caps to the buffer with gst_buffer_set_caps(); this
66 * is typically done before pushing out a buffer using gst_pad_push() so that
67 * the downstream element knows the type of the buffer.
69 * A buffer will usually have a timestamp, and a duration, but neither of these
70 * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
71 * meaningful value can be given for these, they should be set. The timestamp
72 * and duration are measured in nanoseconds (they are #GstClockTime values).
74 * A buffer can also have one or both of a start and an end offset. These are
75 * media-type specific. For video buffers, the start offset will generally be
76 * the frame number. For audio buffers, it will be the number of samples
77 * produced so far. For compressed data, it could be the byte offset in a
78 * source or destination file. Likewise, the end offset will be the offset of
79 * the end of the buffer. These can only be meaningfully interpreted if you
80 * know the media type of the buffer (the #GstCaps set on it). Either or both
81 * can be set to #GST_BUFFER_OFFSET_NONE.
83 * gst_buffer_ref() is used to increase the refcount of a buffer. This must be
84 * done when you want to keep a handle to the buffer after pushing it to the
87 * To efficiently create a smaller buffer out of an existing one, you can
88 * use gst_buffer_create_sub().
90 * If a plug-in wants to modify the buffer data in-place, it should first obtain
91 * a buffer that is safe to modify by using gst_buffer_make_writable(). This
92 * function is optimized so that a copy will only be made when it is necessary.
94 * A plugin that only wishes to modify the metadata of a buffer, such as the
95 * offset, timestamp or caps, should use gst_buffer_make_metadata_writable(),
96 * which will create a subbuffer of the original buffer to ensure the caller
97 * has sole ownership, and not copy the buffer data.
99 * Several flags of the buffer can be set and unset with the
100 * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
101 * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlag is set.
103 * Buffers can be efficiently merged into a larger buffer with
104 * gst_buffer_merge() and gst_buffer_span() if the gst_buffer_is_span_fast()
105 * function returns TRUE.
107 * An element should either unref the buffer or push it out on a src pad
108 * using gst_pad_push() (see #GstPad).
110 * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
111 * the refcount drops to 0, any data pointed to by GST_BUFFER_MALLOCDATA() will
114 * Last reviewed on August 11th, 2006 (0.10.10)
116 #include "gst_private.h"
118 #include "gstbuffer.h"
120 #include "gstutils.h"
121 #include "gstminiobject.h"
123 static void gst_buffer_init (GTypeInstance * instance, gpointer g_class);
124 static void gst_buffer_class_init (gpointer g_class, gpointer class_data);
125 static void gst_buffer_finalize (GstBuffer * buffer);
126 static GstBuffer *_gst_buffer_copy (GstBuffer * buffer);
127 static GType gst_subbuffer_get_type (void);
129 static GType _gst_subbuffer_type = 0;
130 static GType _gst_buffer_type = 0;
133 _gst_buffer_initialize (void)
137 gst_buffer_get_type ();
138 gst_subbuffer_get_type ();
140 /* the GstMiniObject types need to be class_ref'd once before it can be
141 * done from multiple threads;
142 * see http://bugzilla.gnome.org/show_bug.cgi?id=304551 */
143 ptr = g_type_class_ref (GST_TYPE_BUFFER);
144 g_type_class_unref (ptr);
145 ptr = g_type_class_ref (_gst_subbuffer_type);
146 g_type_class_unref (ptr);
150 gst_buffer_get_type (void)
152 if (G_UNLIKELY (_gst_buffer_type == 0)) {
153 static const GTypeInfo buffer_info = {
154 sizeof (GstBufferClass),
157 gst_buffer_class_init,
166 _gst_buffer_type = g_type_register_static (GST_TYPE_MINI_OBJECT,
167 "GstBuffer", &buffer_info, 0);
169 return _gst_buffer_type;
173 gst_buffer_class_init (gpointer g_class, gpointer class_data)
175 GstBufferClass *buffer_class = GST_BUFFER_CLASS (g_class);
177 buffer_class->mini_object_class.copy =
178 (GstMiniObjectCopyFunction) _gst_buffer_copy;
179 buffer_class->mini_object_class.finalize =
180 (GstMiniObjectFinalizeFunction) gst_buffer_finalize;
185 gst_buffer_finalize (GstBuffer * buffer)
187 g_return_if_fail (buffer != NULL);
189 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
192 g_free (buffer->malloc_data);
194 gst_caps_replace (&GST_BUFFER_CAPS (buffer), NULL);
198 * gst_buffer_copy_metadata:
199 * @dest: a destination #GstBuffer
200 * @src: a source #GstBuffer
201 * @flags: flags indicating what metadata fields should be copied.
203 * Copies the metadata from @src into @dest. The data, size and mallocdata
204 * fields are not copied.
206 * @flags indicate which fields will be copied. Use #GST_BUFFER_COPY_ALL to copy
207 * all the metadata fields.
209 * This function is typically called from a custom buffer copy function after
210 * creating @dest and setting the data, size, mallocdata.
215 gst_buffer_copy_metadata (GstBuffer * dest, const GstBuffer * src,
216 GstBufferCopyFlags flags)
218 g_return_if_fail (dest != NULL);
219 g_return_if_fail (src != NULL);
221 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p", src, dest);
223 if (flags & GST_BUFFER_COPY_FLAGS) {
226 /* copy relevant flags */
227 mask = GST_BUFFER_FLAG_PREROLL | GST_BUFFER_FLAG_IN_CAPS |
228 GST_BUFFER_FLAG_DELTA_UNIT | GST_BUFFER_FLAG_DISCONT |
230 GST_MINI_OBJECT_FLAGS (dest) |= GST_MINI_OBJECT_FLAGS (src) & mask;
233 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
234 GST_BUFFER_TIMESTAMP (dest) = GST_BUFFER_TIMESTAMP (src);
235 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
236 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
237 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
240 if (flags & GST_BUFFER_COPY_CAPS) {
241 if (GST_BUFFER_CAPS (src))
242 GST_BUFFER_CAPS (dest) = gst_caps_ref (GST_BUFFER_CAPS (src));
244 GST_BUFFER_CAPS (dest) = NULL;
249 _gst_buffer_copy (GstBuffer * buffer)
253 g_return_val_if_fail (buffer != NULL, NULL);
255 /* create a fresh new buffer */
256 copy = gst_buffer_new ();
258 /* we simply copy everything from our parent */
259 copy->data = g_memdup (buffer->data, buffer->size);
260 /* make sure it gets freed (even if the parent is subclassed, we return a
262 copy->malloc_data = copy->data;
263 copy->size = buffer->size;
265 gst_buffer_copy_metadata (copy, buffer, GST_BUFFER_COPY_ALL);
271 gst_buffer_init (GTypeInstance * instance, gpointer g_class)
275 buffer = (GstBuffer *) instance;
277 GST_CAT_LOG (GST_CAT_BUFFER, "init %p", buffer);
279 GST_BUFFER_TIMESTAMP (buffer) = GST_CLOCK_TIME_NONE;
280 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
281 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
282 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
288 * Creates a newly allocated buffer without any data.
291 * Returns: the new #GstBuffer.
294 gst_buffer_new (void)
298 newbuf = (GstBuffer *) gst_mini_object_new (_gst_buffer_type);
300 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
306 * gst_buffer_new_and_alloc:
307 * @size: the size of the new buffer's data.
309 * Creates a newly allocated buffer with data of the given size.
310 * The buffer memory is not cleared. If the requested amount of
311 * memory can't be allocated, the program will abort. Use
312 * gst_buffer_try_new_and_alloc() if you want to handle this case
313 * gracefully or have gotten the size to allocate from an untrusted
314 * source such as a media stream.
317 * Note that when @size == 0, the buffer data pointer will be NULL.
320 * Returns: the new #GstBuffer.
323 gst_buffer_new_and_alloc (guint size)
327 newbuf = gst_buffer_new ();
329 newbuf->malloc_data = g_malloc (size);
330 GST_BUFFER_DATA (newbuf) = newbuf->malloc_data;
331 GST_BUFFER_SIZE (newbuf) = size;
333 GST_CAT_LOG (GST_CAT_BUFFER, "new %p of size %d", newbuf, size);
339 * gst_buffer_try_new_and_alloc:
340 * @size: the size of the new buffer's data.
342 * Tries to create a newly allocated buffer with data of the given size. If
343 * the requested amount of memory can't be allocated, NULL will be returned.
344 * The buffer memory is not cleared.
346 * Note that when @size == 0, the buffer data pointer will be NULL.
350 * Returns: a new #GstBuffer, or NULL if the memory couldn't be allocated.
355 gst_buffer_try_new_and_alloc (guint size)
360 malloc_data = g_try_malloc (size);
362 if (G_UNLIKELY (malloc_data == NULL && size != 0)) {
363 GST_CAT_WARNING (GST_CAT_BUFFER, "failed to allocate %d bytes", size);
367 /* FIXME: there's no g_type_try_create_instance() in GObject yet, so this
368 * will still abort if a new GstBuffer structure can't be allocated */
369 newbuf = gst_buffer_new ();
371 GST_BUFFER_MALLOCDATA (newbuf) = malloc_data;
372 GST_BUFFER_DATA (newbuf) = malloc_data;
373 GST_BUFFER_SIZE (newbuf) = size;
375 GST_CAT_LOG (GST_CAT_BUFFER, "new %p of size %d", newbuf, size);
381 * gst_buffer_get_caps:
382 * @buffer: a #GstBuffer.
384 * Gets the media type of the buffer. This can be NULL if there
385 * is no media type attached to this buffer.
387 * Returns: a reference to the #GstCaps. unref after usage.
388 * Returns NULL if there were no caps on this buffer.
390 /* FIXME can we make this threadsafe without a lock on the buffer?
391 * We can use compare and swap and atomic reads. */
393 gst_buffer_get_caps (GstBuffer * buffer)
397 g_return_val_if_fail (buffer != NULL, NULL);
399 ret = GST_BUFFER_CAPS (buffer);
408 * gst_buffer_set_caps:
409 * @buffer: a #GstBuffer.
412 * Sets the media type on the buffer. The refcount of the caps will
413 * be increased and any previous caps on the buffer will be
416 /* FIXME can we make this threadsafe without a lock on the buffer?
417 * We can use compare and swap and atomic reads. Another idea is to
418 * not attach the caps to the buffer but use an event to signal a caps
421 gst_buffer_set_caps (GstBuffer * buffer, GstCaps * caps)
423 g_return_if_fail (buffer != NULL);
425 gst_caps_replace (&GST_BUFFER_CAPS (buffer), caps);
429 * gst_buffer_is_metadata_writable:
432 * Similar to gst_buffer_is_writable, but this only ensures that the
433 * refcount of the buffer is 1, indicating that the caller is the sole
434 * owner and can change the buffer metadata, such as caps and timestamps.
436 * Returns: TRUE if the metadata is writable.
439 gst_buffer_is_metadata_writable (GstBuffer * buf)
441 return (GST_MINI_OBJECT_REFCOUNT_VALUE (GST_MINI_OBJECT_CAST (buf)) == 1);
445 * gst_buffer_make_metadata_writable:
448 * Similar to gst_buffer_make_writable, but does not ensure that the buffer
449 * data array is writable. Instead, this just ensures that the returned buffer
450 * is solely owned by the caller, by creating a subbuffer of the original
451 * buffer if necessary.
453 * After calling this function, @buf should not be referenced anymore. The
454 * result of this function has guaranteed writable metadata.
456 * Returns: A new #GstBuffer with writable metadata.
459 gst_buffer_make_metadata_writable (GstBuffer * buf)
463 if (gst_buffer_is_metadata_writable (buf)) {
466 ret = gst_buffer_create_sub (buf, 0, GST_BUFFER_SIZE (buf));
468 /* copy all the flags except IN_CAPS */
469 GST_BUFFER_FLAGS (ret) = GST_BUFFER_FLAGS (buf);
470 GST_BUFFER_FLAG_UNSET (ret, GST_BUFFER_FLAG_IN_CAPS);
471 /* data should always be set to READONLY */
472 GST_BUFFER_FLAG_SET (ret, GST_BUFFER_FLAG_READONLY);
474 gst_buffer_unref (buf);
480 typedef struct _GstSubBuffer GstSubBuffer;
481 typedef struct _GstSubBufferClass GstSubBufferClass;
483 #define GST_IS_SUBBUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), _gst_subbuffer_type))
484 #define GST_SUBBUFFER_CAST(obj) ((GstSubBuffer *)(obj))
493 struct _GstSubBufferClass
495 GstBufferClass buffer_class;
498 static GstBufferClass *sub_parent_class;
500 static void gst_subbuffer_init (GTypeInstance * instance, gpointer g_class);
501 static void gst_subbuffer_class_init (gpointer g_class, gpointer class_data);
502 static void gst_subbuffer_finalize (GstSubBuffer * buffer);
505 gst_subbuffer_get_type (void)
507 if (G_UNLIKELY (_gst_subbuffer_type == 0)) {
508 static const GTypeInfo subbuffer_info = {
509 sizeof (GstSubBufferClass),
512 gst_subbuffer_class_init,
515 sizeof (GstSubBuffer),
521 _gst_subbuffer_type = g_type_register_static (GST_TYPE_BUFFER,
522 "GstSubBuffer", &subbuffer_info, 0);
524 return _gst_subbuffer_type;
528 gst_subbuffer_class_init (gpointer g_class, gpointer class_data)
530 GstBufferClass *buffer_class = GST_BUFFER_CLASS (g_class);
532 sub_parent_class = g_type_class_peek_parent (g_class);
534 buffer_class->mini_object_class.finalize =
535 (GstMiniObjectFinalizeFunction) gst_subbuffer_finalize;
539 gst_subbuffer_finalize (GstSubBuffer * buffer)
541 gst_buffer_unref (buffer->parent);
543 GST_MINI_OBJECT_CLASS (sub_parent_class)->
544 finalize (GST_MINI_OBJECT_CAST (buffer));
548 gst_subbuffer_init (GTypeInstance * instance, gpointer g_class)
550 GST_BUFFER_FLAG_SET (GST_BUFFER_CAST (instance), GST_BUFFER_FLAG_READONLY);
554 * gst_buffer_create_sub:
555 * @parent: a #GstBuffer.
556 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
558 * @size: the size of the new #GstBuffer sub-buffer, in bytes.
560 * Creates a sub-buffer from @parent at @offset and @size.
561 * This sub-buffer uses the actual memory space of the parent buffer.
562 * This function will copy the offset and timestamp fields when the
563 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
564 * #GST_BUFFER_OFFSET_NONE.
565 * If @offset equals 0 and @size equals the total size of @buffer, the
566 * duration and offset end fields are also copied. If not they will be set
567 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
570 * Returns: the new #GstBuffer.
571 * Returns NULL if the arguments were invalid.
574 gst_buffer_create_sub (GstBuffer * buffer, guint offset, guint size)
576 GstSubBuffer *subbuffer;
580 g_return_val_if_fail (buffer != NULL, NULL);
581 g_return_val_if_fail (buffer->mini_object.refcount > 0, NULL);
582 g_return_val_if_fail (buffer->size >= offset + size, NULL);
584 /* find real parent */
585 if (GST_IS_SUBBUFFER (buffer)) {
586 parent = GST_SUBBUFFER_CAST (buffer)->parent;
590 gst_buffer_ref (parent);
592 /* create the new buffer */
593 subbuffer = (GstSubBuffer *) gst_mini_object_new (_gst_subbuffer_type);
594 subbuffer->parent = parent;
596 GST_CAT_LOG (GST_CAT_BUFFER, "new subbuffer %p (parent %p)", subbuffer,
599 /* set the right values in the child */
600 GST_BUFFER_DATA (GST_BUFFER_CAST (subbuffer)) = buffer->data + offset;
601 GST_BUFFER_SIZE (GST_BUFFER_CAST (subbuffer)) = size;
603 /* we can copy the timestamp and offset if the new buffer starts at
606 GST_BUFFER_TIMESTAMP (subbuffer) = GST_BUFFER_TIMESTAMP (buffer);
607 GST_BUFFER_OFFSET (subbuffer) = GST_BUFFER_OFFSET (buffer);
608 complete = (buffer->size == size);
610 GST_BUFFER_TIMESTAMP (subbuffer) = GST_CLOCK_TIME_NONE;
611 GST_BUFFER_OFFSET (subbuffer) = GST_BUFFER_OFFSET_NONE;
618 /* if we copied the complete buffer we can copy the duration,
619 * offset_end and caps as well */
620 GST_BUFFER_DURATION (subbuffer) = GST_BUFFER_DURATION (buffer);
621 GST_BUFFER_OFFSET_END (subbuffer) = GST_BUFFER_OFFSET_END (buffer);
622 if ((caps = GST_BUFFER_CAPS (buffer)))
624 GST_BUFFER_CAPS (subbuffer) = caps;
626 GST_BUFFER_DURATION (subbuffer) = GST_CLOCK_TIME_NONE;
627 GST_BUFFER_OFFSET_END (subbuffer) = GST_BUFFER_OFFSET_NONE;
628 GST_BUFFER_CAPS (subbuffer) = NULL;
630 return GST_BUFFER_CAST (subbuffer);
634 * gst_buffer_is_span_fast:
635 * @buf1: the first #GstBuffer.
636 * @buf2: the second #GstBuffer.
638 * Determines whether a gst_buffer_span() can be done without copying
639 * the contents, that is, whether the data areas are contiguous sub-buffers of
643 * Returns: TRUE if the buffers are contiguous,
644 * FALSE if a copy would be required.
647 gst_buffer_is_span_fast (GstBuffer * buf1, GstBuffer * buf2)
649 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, FALSE);
650 g_return_val_if_fail (buf1->mini_object.refcount > 0, FALSE);
651 g_return_val_if_fail (buf2->mini_object.refcount > 0, FALSE);
653 /* it's only fast if we have subbuffers of the same parent */
654 return (GST_IS_SUBBUFFER (buf1) &&
655 GST_IS_SUBBUFFER (buf2) &&
656 (GST_SUBBUFFER_CAST (buf1)->parent == GST_SUBBUFFER_CAST (buf2)->parent)
657 && ((buf1->data + buf1->size) == buf2->data));
662 * @buf1: the first source #GstBuffer to merge.
663 * @offset: the offset in the first buffer from where the new
664 * buffer should start.
665 * @buf2: the second source #GstBuffer to merge.
666 * @len: the total length of the new buffer.
668 * Creates a new buffer that consists of part of buf1 and buf2.
669 * Logically, buf1 and buf2 are concatenated into a single larger
670 * buffer, and a new buffer is created at the given offset inside
671 * this space, with a given length.
673 * If the two source buffers are children of the same larger buffer,
674 * and are contiguous, the new buffer will be a child of the shared
675 * parent, and thus no copying is necessary. you can use
676 * gst_buffer_is_span_fast() to determine if a memcpy will be needed.
679 * Returns: the new #GstBuffer that spans the two source buffers.
680 * Returns NULL if the arguments are invalid.
683 gst_buffer_span (GstBuffer * buf1, guint32 offset, GstBuffer * buf2,
688 g_return_val_if_fail (buf1 != NULL && buf2 != NULL, NULL);
689 g_return_val_if_fail (buf1->mini_object.refcount > 0, NULL);
690 g_return_val_if_fail (buf2->mini_object.refcount > 0, NULL);
691 g_return_val_if_fail (len > 0, NULL);
692 g_return_val_if_fail (len <= buf1->size + buf2->size - offset, NULL);
694 /* if the two buffers have the same parent and are adjacent */
695 if (gst_buffer_is_span_fast (buf1, buf2)) {
696 GstBuffer *parent = GST_SUBBUFFER_CAST (buf1)->parent;
698 /* we simply create a subbuffer of the common parent */
699 newbuf = gst_buffer_create_sub (parent,
700 buf1->data - parent->data + offset, len);
702 GST_CAT_DEBUG (GST_CAT_BUFFER,
703 "slow path taken while spanning buffers %p and %p", buf1, buf2);
704 /* otherwise we simply have to brute-force copy the buffers */
705 newbuf = gst_buffer_new_and_alloc (len);
707 /* copy the first buffer's data across */
708 memcpy (newbuf->data, buf1->data + offset, buf1->size - offset);
709 /* copy the second buffer's data across */
710 memcpy (newbuf->data + (buf1->size - offset), buf2->data,
711 len - (buf1->size - offset));
713 /* if the offset is 0, the new buffer has the same timestamp as buf1 */
715 GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET (buf1);
716 GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf1);
718 /* if we completely merged the two buffers (appended), we can
719 * calculate the duration too. Also make sure we's not messing with
720 * invalid DURATIONS */
721 if (buf1->size + buf2->size == len) {
722 if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
723 GST_BUFFER_DURATION_IS_VALID (buf2)) {
725 GST_BUFFER_DURATION (newbuf) = GST_BUFFER_DURATION (buf1) +
726 GST_BUFFER_DURATION (buf2);
728 if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
730 GST_BUFFER_OFFSET_END (newbuf) = GST_BUFFER_OFFSET_END (buf2);