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
26 * @see_also: #GstPad, #GstMiniObject, #GstMemory, #GstMeta, #GstBufferPool
28 * Buffers are the basic unit of data transfer in GStreamer. They contain the
29 * timing and offset along with other arbitrary metadata that is associated
30 * with the #GstMemory blocks that the buffer contains.
32 * Buffers are usually created with gst_buffer_new(). After a buffer has been
33 * created one will typically allocate memory for it and add it to the buffer.
34 * The following example creates a buffer that can hold a given video frame
35 * with a given width, height and bits per plane.
37 * <title>Creating a buffer for a video frame</title>
41 * gint size, width, height, bpp;
43 * size = width * height * bpp;
44 * buffer = gst_buffer_new ();
45 * memory = gst_allocator_alloc (NULL, size, NULL);
46 * gst_buffer_insert_memory (buffer, -1, memory);
51 * Alternatively, use gst_buffer_new_allocate()
52 * to create a buffer with preallocated data of a given size.
54 * Buffers can contain a list of #GstMemory objects. You can retrieve how many
55 * memory objects with gst_buffer_n_memory() and you can get a pointer
56 * to memory with gst_buffer_peek_memory()
58 * A buffer will usually have timestamps, and a duration, but neither of these
59 * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
60 * meaningful value can be given for these, they should be set. The timestamps
61 * and duration are measured in nanoseconds (they are #GstClockTime values).
63 * The buffer DTS refers to the timestamp when the buffer should be decoded and
64 * is usually monotonically increasing. The buffer PTS refers to the timestamp when
65 * the buffer content should be presented to the user and is not always
66 * monotonically increasing.
68 * A buffer can also have one or both of a start and an end offset. These are
69 * media-type specific. For video buffers, the start offset will generally be
70 * the frame number. For audio buffers, it will be the number of samples
71 * produced so far. For compressed data, it could be the byte offset in a
72 * source or destination file. Likewise, the end offset will be the offset of
73 * the end of the buffer. These can only be meaningfully interpreted if you
74 * know the media type of the buffer (the preceeding CAPS event). Either or both
75 * can be set to #GST_BUFFER_OFFSET_NONE.
77 * gst_buffer_ref() is used to increase the refcount of a buffer. This must be
78 * done when you want to keep a handle to the buffer after pushing it to the
79 * next element. The buffer refcount determines the writability of the buffer, a
80 * buffer is only writable when the refcount is exactly 1, i.e. when the caller
81 * has the only reference to the buffer.
83 * To efficiently create a smaller buffer out of an existing one, you can
84 * use gst_buffer_copy_region(). This method tries to share the memory objects
85 * between the two buffers.
87 * If a plug-in wants to modify the buffer data or metadata in-place, it should
88 * first obtain a buffer that is safe to modify by using
89 * gst_buffer_make_writable(). This function is optimized so that a copy will
90 * only be made when it is necessary.
92 * Several flags of the buffer can be set and unset with the
93 * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
94 * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlag is set.
96 * Buffers can be efficiently merged into a larger buffer with
97 * gst_buffer_append(). Copying of memory will only be done when absolutely
100 * Arbitrary extra metadata can be set on a buffer with gst_buffer_add_meta().
101 * Metadata can be retrieved with gst_buffer_get_meta(). See also #GstMeta
103 * An element should either unref the buffer or push it out on a src pad
104 * using gst_pad_push() (see #GstPad).
106 * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
107 * the refcount drops to 0, any memory and metadata pointed to by the buffer is
108 * unreffed as well. Buffers allocated from a #GstBufferPool will be returned to
109 * the pool when the refcount drops to 0.
111 * Last reviewed on 2012-03-28 (0.11.3)
113 #include "gst_private.h"
122 #include "gstbuffer.h"
123 #include "gstbufferpool.h"
125 #include "gstutils.h"
126 #include "gstversion.h"
128 GType _gst_buffer_type = 0;
130 typedef struct _GstMetaItem GstMetaItem;
137 #define ITEM_SIZE(info) ((info)->size + sizeof (GstMetaItem))
139 #define GST_BUFFER_MEM_MAX 16
141 #define GST_BUFFER_SLICE_SIZE(b) (((GstBufferImpl *)(b))->slice_size)
142 #define GST_BUFFER_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
143 #define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
144 #define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
145 #define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
146 #define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
154 /* the memory blocks */
156 GstMemory *mem[GST_BUFFER_MEM_MAX];
158 /* memory of the buffer when allocated from 1 chunk */
161 /* FIXME, make metadata allocation more efficient by using part of the
168 _is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
170 GstMemory *mcur, *mprv;
171 gboolean have_offset = FALSE;
176 for (i = 0; i < len; i++) {
184 /* check if memory is contiguous */
185 if (!gst_memory_is_span (mprv, mcur, &poffs))
192 *parent = mprv->parent;
202 _get_merged_memory (GstBuffer * buffer, guint idx, guint length)
204 GstMemory **mem, *result;
206 mem = GST_BUFFER_MEM_ARRAY (buffer);
208 if (G_UNLIKELY (length == 0)) {
210 } else if (G_LIKELY (length == 1)) {
211 result = gst_memory_ref (mem[idx]);
213 GstMemory *parent = NULL;
214 gsize size, poffset = 0;
216 size = gst_buffer_get_size (buffer);
218 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
220 if (GST_MEMORY_IS_NO_SHARE (parent)) {
221 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
222 result = gst_memory_copy (parent, poffset, size);
224 result = gst_memory_share (parent, poffset, size);
227 gsize i, tocopy, left;
228 GstMapInfo sinfo, dinfo;
231 result = gst_allocator_alloc (NULL, size, NULL);
232 gst_memory_map (result, &dinfo, GST_MAP_WRITE);
237 for (i = idx; i < length && left > 0; i++) {
238 gst_memory_map (mem[i], &sinfo, GST_MAP_READ);
239 tocopy = MIN (sinfo.size, left);
240 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
241 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
242 tocopy, result, mem[i]);
243 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
246 gst_memory_unmap (mem[i], &sinfo);
248 gst_memory_unmap (result, &dinfo);
255 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
261 GST_LOG ("buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer,
264 /* unref old memory */
265 for (i = idx; i < end; i++)
266 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
269 /* replace with single memory */
270 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
276 g_memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
277 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
279 GST_BUFFER_MEM_LEN (buffer) = len - length;
283 _memory_add (GstBuffer * buffer, guint idx, GstMemory * mem)
285 guint i, len = GST_BUFFER_MEM_LEN (buffer);
287 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
288 /* too many buffer, span them. */
289 /* FIXME, there is room for improvement here: We could only try to merge
290 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
291 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
292 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
294 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
295 /* we now have 1 single spanned buffer */
302 for (i = len; i > idx; i--) {
303 /* move buffers to insert, FIXME, we need to insert first and then merge */
304 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
306 /* and insert the new buffer */
307 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
308 GST_BUFFER_MEM_LEN (buffer) = len + 1;
311 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
314 _priv_gst_buffer_initialize (void)
316 _gst_buffer_type = gst_buffer_get_type ();
320 * gst_buffer_copy_into:
321 * @dest: a destination #GstBuffer
322 * @src: a source #GstBuffer
323 * @flags: flags indicating what metadata fields should be copied.
324 * @offset: offset to copy from
325 * @size: total size to copy. If -1, all data is copied.
327 * Copies the information from @src into @dest.
329 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
330 * the memory from @src will be appended to @dest.
332 * @flags indicate which fields will be copied.
335 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
336 GstBufferCopyFlags flags, gsize offset, gsize size)
340 gboolean region = FALSE;
342 g_return_if_fail (dest != NULL);
343 g_return_if_fail (src != NULL);
345 /* nothing to copy if the buffers are the same */
346 if (G_UNLIKELY (dest == src))
349 g_return_if_fail (gst_buffer_is_writable (dest));
351 bufsize = gst_buffer_get_size (src);
352 g_return_if_fail (bufsize >= offset);
356 size = bufsize - offset;
359 g_return_if_fail (bufsize >= offset + size);
361 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
362 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
365 if (flags & GST_BUFFER_COPY_FLAGS) {
367 GST_MINI_OBJECT_FLAGS (dest) = GST_MINI_OBJECT_FLAGS (src);
370 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
372 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
373 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
374 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
375 if (size == bufsize) {
376 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
377 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
380 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
381 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
382 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
383 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
384 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
388 if (flags & GST_BUFFER_COPY_MEMORY) {
390 gsize skip, left, len, i, bsize;
392 len = GST_BUFFER_MEM_LEN (src);
396 /* copy and make regions of the memory */
397 for (i = 0; i < len && left > 0; i++) {
398 mem = GST_BUFFER_MEM_PTR (src, i);
399 bsize = gst_memory_get_sizes (mem, NULL, NULL);
402 /* don't copy buffer */
407 tocopy = MIN (bsize - skip, left);
408 if (GST_MEMORY_IS_NO_SHARE (mem)) {
409 /* no share, always copy then */
410 mem = gst_memory_copy (mem, skip, tocopy);
412 } else if (tocopy < bsize) {
413 /* we need to clip something */
414 mem = gst_memory_share (mem, skip, tocopy);
417 mem = gst_memory_ref (mem);
419 _memory_add (dest, -1, mem);
423 if (flags & GST_BUFFER_COPY_MERGE) {
424 len = GST_BUFFER_MEM_LEN (dest);
425 _replace_memory (dest, len, 0, len, _get_merged_memory (dest, 0, len));
429 if (flags & GST_BUFFER_COPY_META) {
430 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
431 GstMeta *meta = &walk->meta;
432 const GstMetaInfo *info = meta->info;
434 if (info->transform_func) {
435 GstMetaTransformCopy copy_data;
437 copy_data.region = region;
438 copy_data.offset = offset;
439 copy_data.size = size;
441 info->transform_func (dest, meta, src,
442 _gst_meta_transform_copy, ©_data);
449 _gst_buffer_copy (GstBuffer * buffer)
453 g_return_val_if_fail (buffer != NULL, NULL);
455 /* create a fresh new buffer */
456 copy = gst_buffer_new ();
458 /* we simply copy everything from our parent */
459 gst_buffer_copy_into (copy, buffer, GST_BUFFER_COPY_ALL, 0, -1);
464 /* the default dispose function revives the buffer and returns it to the
465 * pool when there is a pool */
467 _gst_buffer_dispose (GstBuffer * buffer)
471 /* no pool, do free */
472 if ((pool = buffer->pool) == NULL)
475 /* keep the buffer alive */
476 gst_buffer_ref (buffer);
477 /* return the buffer to the pool */
478 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
479 gst_buffer_pool_release_buffer (pool, buffer);
485 _gst_buffer_free (GstBuffer * buffer)
487 GstMetaItem *walk, *next;
491 g_return_if_fail (buffer != NULL);
493 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
496 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
497 GstMeta *meta = &walk->meta;
498 const GstMetaInfo *info = meta->info;
500 /* call free_func if any */
502 info->free_func (meta, buffer);
505 /* and free the slice */
506 g_slice_free1 (ITEM_SIZE (info), walk);
509 /* get the size, when unreffing the memory, we could also unref the buffer
511 msize = GST_BUFFER_SLICE_SIZE (buffer);
513 /* free our memory */
514 len = GST_BUFFER_MEM_LEN (buffer);
515 for (i = 0; i < len; i++)
516 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
518 /* we set msize to 0 when the buffer is part of the memory block */
520 g_slice_free1 (msize, buffer);
522 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
526 gst_buffer_init (GstBufferImpl * buffer, gsize size)
528 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), _gst_buffer_type);
530 buffer->buffer.mini_object.copy =
531 (GstMiniObjectCopyFunction) _gst_buffer_copy;
532 buffer->buffer.mini_object.dispose =
533 (GstMiniObjectDisposeFunction) _gst_buffer_dispose;
534 buffer->buffer.mini_object.free =
535 (GstMiniObjectFreeFunction) _gst_buffer_free;
537 GST_BUFFER_SLICE_SIZE (buffer) = size;
539 GST_BUFFER (buffer)->pool = NULL;
540 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
541 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
542 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
543 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
544 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
546 GST_BUFFER_MEM_LEN (buffer) = 0;
547 GST_BUFFER_META (buffer) = NULL;
553 * Creates a newly allocated buffer without any data.
557 * Returns: (transfer full): the new #GstBuffer.
560 gst_buffer_new (void)
562 GstBufferImpl *newbuf;
564 newbuf = g_slice_new (GstBufferImpl);
565 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
567 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
569 return GST_BUFFER_CAST (newbuf);
573 * gst_buffer_new_allocate:
574 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or NULL to use the
576 * @size: the size in bytes of the new buffer's data.
577 * @params: (transfer none) (allow-none): optional parameters
579 * Tries to create a newly allocated buffer with data of the given size and
580 * extra parameters from @allocator. If the requested amount of memory can't be
581 * allocated, NULL will be returned. The allocated buffer memory is not cleared.
583 * When @allocator is NULL, the default memory allocator will be used.
585 * Note that when @size == 0, the buffer will not have memory associated with it.
589 * Returns: (transfer full): a new #GstBuffer, or NULL if the memory couldn't
593 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
594 GstAllocationParams * params)
605 mem = gst_allocator_alloc (allocator, size, params);
606 if (G_UNLIKELY (mem == NULL))
612 newbuf = gst_buffer_new ();
615 _memory_add (newbuf, -1, mem);
617 GST_CAT_LOG (GST_CAT_BUFFER,
618 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
623 asize = sizeof (GstBufferImpl) + size;
624 data = g_slice_alloc (asize);
625 if (G_UNLIKELY (data == NULL))
628 newbuf = GST_BUFFER_CAST (data);
630 gst_buffer_init ((GstBufferImpl *) data, asize);
632 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
634 _memory_add (newbuf, -1, mem);
639 /* allocate memory and buffer, it might be interesting to do this but there
640 * are many complications. We need to keep the memory mapped to access the
641 * buffer fields and the memory for the buffer might be just very slow. We
642 * also need to do some more magic to get the alignment right. */
643 asize = sizeof (GstBufferImpl) + size;
644 mem = gst_allocator_alloc (allocator, asize, align);
645 if (G_UNLIKELY (mem == NULL))
648 /* map the data part and init the buffer in it, set the buffer size to 0 so
649 * that a finalize won't free the buffer */
650 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
651 gst_buffer_init ((GstBufferImpl *) data, 0);
652 gst_memory_unmap (mem);
654 /* strip off the buffer */
655 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
657 newbuf = GST_BUFFER_CAST (data);
658 GST_BUFFER_BUFMEM (newbuf) = mem;
661 _memory_add (newbuf, -1, gst_memory_ref (mem));
669 GST_CAT_WARNING (GST_CAT_BUFFER,
670 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
676 * gst_buffer_new_wrapped_full:
677 * @flags: #GstMemoryFlags
678 * @data: data to wrap
679 * @maxsize: allocated size of @data
680 * @offset: offset in @data
681 * @size: size of valid data
682 * @user_data: user_data
683 * @notify: called with @user_data when the memory is freed
685 * Allocate a new buffer that wraps the given memory. @data must point to
686 * @maxsize of memory, the wrapped buffer will have the region from @offset and
689 * When the buffer is destroyed, @notify will be called with @user_data.
691 * The prefix/padding must be filled with 0 if @flags contains
692 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
694 * Returns: (transfer full): a new #GstBuffer
697 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
698 gsize maxsize, gsize offset, gsize size, gpointer user_data,
699 GDestroyNotify notify)
703 newbuf = gst_buffer_new ();
704 gst_buffer_append_memory (newbuf,
705 gst_memory_new_wrapped (flags, data, maxsize, offset, size,
712 * gst_buffer_new_wrapped:
713 * @data: data to wrap
714 * @size: allocated size of @data
716 * Creates a new buffer that wraps the given @data. The memory will be freed
717 * with g_free and will be marked writable.
721 * Returns: (transfer full): a new #GstBuffer
724 gst_buffer_new_wrapped (gpointer data, gsize size)
726 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
730 * gst_buffer_n_memory:
731 * @buffer: a #GstBuffer.
733 * Get the amount of memory blocks that this buffer has.
735 * Returns: (transfer full): the amount of memory block in this buffer.
738 gst_buffer_n_memory (GstBuffer * buffer)
740 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
742 return GST_BUFFER_MEM_LEN (buffer);
746 * gst_buffer_insert_memory:
747 * @buffer: a #GstBuffer.
748 * @idx: the index to add the memory at, or -1 to append it to the end
749 * @mem: (transfer full): a #GstMemory.
751 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
752 * of @mem and thus doesn't increase its refcount.
755 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
757 g_return_if_fail (GST_IS_BUFFER (buffer));
758 g_return_if_fail (gst_buffer_is_writable (buffer));
759 g_return_if_fail (mem != NULL);
760 g_return_if_fail (idx == -1 ||
761 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
763 _memory_add (buffer, idx, mem);
767 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
770 GstMemory *mem, *mapped;
772 mem = GST_BUFFER_MEM_PTR (buffer, idx);
774 mapped = gst_memory_make_mapped (mem, info, flags);
779 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
780 gst_memory_unref (mem);
787 * gst_buffer_peek_memory:
788 * @buffer: a #GstBuffer.
791 * Get the memory block at @idx in @buffer. The memory block stays valid until
792 * the memory block in @buffer is removed, replaced or merged, typically with
793 * any call that modifies the memory in @buffer.
795 * Since this call does not influence the refcount of the memory,
796 * gst_memory_is_exclusive() can be used to check if @buffer is the sole owner
797 * of the returned memory.
799 * Returns: (transfer none): the #GstMemory at @idx.
802 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
806 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
807 len = GST_BUFFER_MEM_LEN (buffer);
808 g_return_val_if_fail (idx < len, NULL);
810 return GST_BUFFER_MEM_PTR (buffer, idx);
814 * gst_buffer_get_memory_range:
815 * @buffer: a #GstBuffer.
819 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
820 * be merged into one large #GstMemory.
822 * If @length is -1, all memory starting from @idx is merged.
824 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
825 * blocks starting at @idx. Use gst_memory_unref () after usage.
828 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
832 GST_DEBUG ("idx %u, length %d", idx, length);
834 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
835 len = GST_BUFFER_MEM_LEN (buffer);
836 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
837 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
842 return _get_merged_memory (buffer, idx, length);
846 * gst_buffer_replace_memory_range:
847 * @buffer: a #GstBuffer.
849 * @length: a length should not be 0
850 * @mem: (transfer full): a #GstMemory
852 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
854 * If @length is -1, all memory starting from @idx will be removed and
855 * replaced with @mem.
857 * @buffer should be writable.
860 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
865 g_return_if_fail (GST_IS_BUFFER (buffer));
866 g_return_if_fail (gst_buffer_is_writable (buffer));
867 len = GST_BUFFER_MEM_LEN (buffer);
868 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
869 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
874 _replace_memory (buffer, len, idx, length, mem);
878 * gst_buffer_remove_memory_range:
879 * @buffer: a #GstBuffer.
883 * Remove @length memory blocks in @buffer starting from @idx.
885 * @length can be -1, in which case all memory starting from @idx is removed.
888 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
892 g_return_if_fail (GST_IS_BUFFER (buffer));
893 g_return_if_fail (gst_buffer_is_writable (buffer));
895 len = GST_BUFFER_MEM_LEN (buffer);
896 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
897 (length == -1 && idx < len) || length + idx <= len);
902 _replace_memory (buffer, len, idx, length, NULL);
906 * gst_buffer_find_memory:
907 * @buffer: a #GstBuffer.
910 * @idx: (out): pointer to index
911 * @length: (out): pointer to length
912 * @skip: (out): pointer to skip
914 * Find the memory blocks that span @size bytes starting from @offset
917 * When this function returns %TRUE, @idx will contain the index of the first
918 * memory bock where the byte for @offset can be found and @length contains the
919 * number of memory blocks containing the @size remaining bytes. @skip contains
920 * the number of bytes to skip in the memory bock at @idx to get to the byte
923 * @size can be -1 to get all the memory blocks after @idx.
925 * Returns: %TRUE when @size bytes starting from @offset could be found in
926 * @buffer and @idx, @length and @skip will be filled.
929 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
930 guint * idx, guint * length, gsize * skip)
934 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
935 g_return_val_if_fail (idx != NULL, FALSE);
936 g_return_val_if_fail (length != NULL, FALSE);
937 g_return_val_if_fail (skip != NULL, FALSE);
939 len = GST_BUFFER_MEM_LEN (buffer);
942 for (i = 0; i < len; i++) {
946 mem = GST_BUFFER_MEM_PTR (buffer, i);
947 s = gst_memory_get_sizes (mem, NULL, NULL);
950 /* block before offset, or empty block, skip */
953 /* block after offset */
955 /* first block, remember index and offset */
959 /* return remaining blocks */
966 /* count the amount of found bytes */
969 /* we have enough bytes */
970 *length = i - *idx + 1;
979 * gst_buffer_get_sizes_range:
980 * @buffer: a #GstBuffer.
983 * @offset: a pointer to the offset
984 * @maxsize: a pointer to the maxsize
986 * Get the total size of @length memory blocks stating from @idx in @buffer.
988 * When not %NULL, @offset will contain the offset of the data in the
989 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
990 * and @offset and the amount of extra padding on the memory block at @idx +
992 * @offset and @maxsize can be used to resize the buffer memory blocks with
993 * gst_buffer_resize_range().
995 * Returns: total size @length memory blocks starting at @idx in @buffer.
998 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
999 gsize * offset, gsize * maxsize)
1005 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1006 len = GST_BUFFER_MEM_LEN (buffer);
1007 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1008 (length == -1 && idx < len) || (length + idx <= len), 0);
1013 if (G_LIKELY (length == 1)) {
1015 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1016 size = gst_memory_get_sizes (mem, offset, maxsize);
1022 size = offs = extra = 0;
1023 for (i = idx; i < end; i++) {
1026 mem = GST_BUFFER_MEM_PTR (buffer, i);
1027 s = gst_memory_get_sizes (mem, &o, &ms);
1031 /* first size, take accumulated data before as the offset */
1035 /* save the amount of data after this block */
1036 extra = ms - (o + s);
1038 /* empty block, add as extra */
1045 *maxsize = offs + size + extra;
1051 * gst_buffer_resize_range:
1052 * @buffer: a #GstBuffer.
1055 * @offset: the offset adjustement
1056 * @size: the new size or -1 to just adjust the offset
1058 * Set the total size of the @length memory blocks starting at @idx in
1062 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1063 gssize offset, gssize size)
1066 gsize bsize, bufsize, bufoffs, bufmax;
1069 g_return_if_fail (gst_buffer_is_writable (buffer));
1070 g_return_if_fail (size >= -1);
1071 len = GST_BUFFER_MEM_LEN (buffer);
1072 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1073 (length == -1 && idx < len) || (length + idx <= len));
1078 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1080 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1081 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1082 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1084 /* we can't go back further than the current offset or past the end of the
1086 g_return_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1087 && bufoffs + offset <= bufmax));
1089 g_return_if_fail (bufsize >= offset);
1090 size = bufsize - offset;
1092 g_return_if_fail (bufmax >= bufoffs + offset + size);
1095 if (offset == 0 && size == bufsize)
1100 for (i = idx; i < end; i++) {
1103 mem = GST_BUFFER_MEM_PTR (buffer, i);
1104 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1107 /* last buffer always gets resized to the remaining size */
1110 /* shrink buffers before the offset */
1111 else if ((gssize) bsize <= offset) {
1113 noffs = offset - bsize;
1116 /* clip other buffers */
1118 left = MIN (bsize - offset, size);
1120 if (offset != 0 || left != bsize) {
1121 if (gst_memory_is_exclusive (mem)) {
1122 gst_memory_resize (mem, offset, left);
1126 if (GST_MEMORY_IS_NO_SHARE (mem))
1127 tmp = gst_memory_copy (mem, offset, left);
1129 tmp = gst_memory_share (mem, offset, left);
1131 gst_memory_unref (mem);
1138 GST_BUFFER_MEM_PTR (buffer, i) = mem;
1143 * gst_buffer_map_range:
1144 * @buffer: a #GstBuffer.
1147 * @info: (out): info about the mapping
1148 * @flags: flags for the mapping
1150 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1151 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1152 * from @idx are merged and mapped.
1153 * @flags describe the desired access of the memory. When @flags is
1154 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1155 * gst_buffer_is_writable()).
1157 * When @buffer is writable but the memory isn't, a writable copy will
1158 * automatically be created and returned. The readonly copy of the buffer memory
1159 * will then also be replaced with this writable copy.
1161 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1163 * Returns: (transfer full): %TRUE if the map succeeded and @info contains valid
1167 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1168 GstMapInfo * info, GstMapFlags flags)
1170 GstMemory *mem, *nmem;
1171 gboolean write, writable;
1174 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1175 g_return_val_if_fail (info != NULL, FALSE);
1176 len = GST_BUFFER_MEM_LEN (buffer);
1177 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1178 (length == -1 && idx < len) || (length > 0
1179 && length + idx <= len), FALSE);
1181 write = (flags & GST_MAP_WRITE) != 0;
1182 writable = gst_buffer_is_writable (buffer);
1184 /* check if we can write when asked for write access */
1185 if (G_UNLIKELY (write && !writable))
1191 mem = _get_merged_memory (buffer, idx, length);
1192 if (G_UNLIKELY (mem == NULL))
1195 /* now try to map */
1196 nmem = gst_memory_make_mapped (mem, info, flags);
1197 if (G_UNLIKELY (nmem == NULL))
1200 /* if we merged or when the map returned a different memory, we try to replace
1201 * the memory in the buffer */
1202 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1203 /* if the buffer is writable, replace the memory */
1205 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1208 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1209 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1218 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1219 g_critical ("write map requested on non-writable buffer");
1224 /* empty buffer, we need to return NULL */
1225 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1226 info->memory = NULL;
1234 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1241 * @buffer: a #GstBuffer.
1242 * @info: a #GstMapInfo
1244 * Release the memory previously mapped with gst_buffer_map().
1247 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1249 g_return_if_fail (GST_IS_BUFFER (buffer));
1250 g_return_if_fail (info != NULL);
1252 /* we need to check for NULL, it is possible that we tried to map a buffer
1253 * without memory and we should be able to unmap that fine */
1254 if (G_LIKELY (info->memory)) {
1255 gst_memory_unmap (info->memory, info);
1256 gst_memory_unref (info->memory);
1262 * @buffer: a #GstBuffer.
1263 * @offset: the offset to fill
1264 * @src: the source address
1265 * @size: the size to fill
1267 * Copy @size bytes from @src to @buffer at @offset.
1269 * Returns: The amount of bytes copied. This value can be lower than @size
1270 * when @buffer did not contain enough data.
1273 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1277 const guint8 *ptr = src;
1279 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1280 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1281 g_return_val_if_fail (src != NULL, 0);
1283 len = GST_BUFFER_MEM_LEN (buffer);
1286 for (i = 0; i < len && left > 0; i++) {
1291 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1292 if (info.size > offset) {
1293 /* we have enough */
1294 tocopy = MIN (info.size - offset, left);
1295 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1300 /* offset past buffer, skip */
1301 offset -= info.size;
1303 gst_memory_unmap (mem, &info);
1309 * gst_buffer_extract:
1310 * @buffer: a #GstBuffer.
1311 * @offset: the offset to extract
1312 * @dest: the destination address
1313 * @size: the size to extract
1315 * Copy @size bytes starting from @offset in @buffer to @dest.
1317 * Returns: The amount of bytes extracted. This value can be lower than @size
1318 * when @buffer did not contain enough data.
1321 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1326 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1327 g_return_val_if_fail (dest != NULL, 0);
1329 len = GST_BUFFER_MEM_LEN (buffer);
1332 for (i = 0; i < len && left > 0; i++) {
1337 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1338 if (info.size > offset) {
1339 /* we have enough */
1340 tocopy = MIN (info.size - offset, left);
1341 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1346 /* offset past buffer, skip */
1347 offset -= info.size;
1349 gst_memory_unmap (mem, &info);
1355 * gst_buffer_memcmp:
1356 * @buffer: a #GstBuffer.
1357 * @offset: the offset in @buffer
1358 * @mem: the memory to compare
1359 * @size: the size to compare
1361 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1363 * Returns: 0 if the memory is equal.
1366 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1370 const guint8 *ptr = mem;
1373 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1374 g_return_val_if_fail (mem != NULL, 0);
1376 len = GST_BUFFER_MEM_LEN (buffer);
1378 for (i = 0; i < len && size > 0 && res == 0; i++) {
1383 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1384 if (info.size > offset) {
1385 /* we have enough */
1386 tocmp = MIN (info.size - offset, size);
1387 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1392 /* offset past buffer, skip */
1393 offset -= info.size;
1395 gst_memory_unmap (mem, &info);
1401 * gst_buffer_memset:
1402 * @buffer: a #GstBuffer.
1403 * @offset: the offset in @buffer
1404 * @val: the value to set
1405 * @size: the size to set
1407 * Fill @buf with @size bytes with @val starting from @offset.
1409 * Returns: The amount of bytes filled. This value can be lower than @size
1410 * when @buffer did not contain enough data.
1413 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1417 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1418 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1420 len = GST_BUFFER_MEM_LEN (buffer);
1423 for (i = 0; i < len && left > 0; i++) {
1428 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1429 if (info.size > offset) {
1430 /* we have enough */
1431 toset = MIN (info.size - offset, left);
1432 memset ((guint8 *) info.data + offset, val, toset);
1436 /* offset past buffer, skip */
1437 offset -= info.size;
1439 gst_memory_unmap (mem, &info);
1445 * gst_buffer_copy_region:
1446 * @parent: a #GstBuffer.
1447 * @flags: the #GstBufferCopyFlags
1448 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1450 * @size: the size of the new #GstBuffer sub-buffer, in bytes.
1452 * Creates a sub-buffer from @parent at @offset and @size.
1453 * This sub-buffer uses the actual memory space of the parent buffer.
1454 * This function will copy the offset and timestamp fields when the
1455 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1456 * #GST_BUFFER_OFFSET_NONE.
1457 * If @offset equals 0 and @size equals the total size of @buffer, the
1458 * duration and offset end fields are also copied. If not they will be set
1459 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1463 * Returns: (transfer full): the new #GstBuffer or NULL if the arguments were
1467 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1468 gsize offset, gsize size)
1472 g_return_val_if_fail (buffer != NULL, NULL);
1474 /* create the new buffer */
1475 copy = gst_buffer_new ();
1477 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1478 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1480 gst_buffer_copy_into (copy, buffer, flags, offset, size);
1486 * gst_buffer_append:
1487 * @buf1: (transfer full): the first source #GstBuffer to append.
1488 * @buf2: (transfer full): the second source #GstBuffer to append.
1490 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1491 * concatenation of the memory of @buf1 and @buf2.
1493 * Returns: (transfer full): the new #GstBuffer that contains the memory
1494 * of the two source buffers.
1497 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1501 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1502 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1504 buf1 = gst_buffer_make_writable (buf1);
1505 buf2 = gst_buffer_make_writable (buf2);
1507 len = GST_BUFFER_MEM_LEN (buf2);
1508 for (i = 0; i < len; i++) {
1511 mem = GST_BUFFER_MEM_PTR (buf2, i);
1512 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1513 _memory_add (buf1, -1, mem);
1516 /* we can calculate the duration too. Also make sure we're not messing
1517 * with invalid DURATIONS */
1518 if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
1519 GST_BUFFER_DURATION_IS_VALID (buf2)) {
1521 GST_BUFFER_DURATION (buf1) += GST_BUFFER_DURATION (buf2);
1523 if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
1524 /* set offset_end */
1525 GST_BUFFER_OFFSET_END (buf1) = GST_BUFFER_OFFSET_END (buf2);
1528 GST_BUFFER_MEM_LEN (buf2) = 0;
1529 gst_buffer_unref (buf2);
1535 * gst_buffer_get_meta:
1536 * @buffer: a #GstBuffer
1537 * @api: the #GType of an API
1539 * Get the metadata for @api on buffer. When there is no such
1540 * metadata, NULL is returned.
1542 * Returns: the metadata for @api on @buffer.
1545 gst_buffer_get_meta (GstBuffer * buffer, GType api)
1548 GstMeta *result = NULL;
1550 g_return_val_if_fail (buffer != NULL, NULL);
1551 g_return_val_if_fail (api != 0, NULL);
1553 /* find GstMeta of the requested API */
1554 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
1555 GstMeta *meta = &item->meta;
1556 if (meta->info->api == api) {
1565 * gst_buffer_add_meta:
1566 * @buffer: a #GstBuffer
1567 * @info: a #GstMetaInfo
1568 * @params: params for @info
1570 * Add metadata for @info to @buffer using the parameters in @params.
1572 * Returns: (transfer none): the metadata for the api in @info on @buffer.
1575 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
1579 GstMeta *result = NULL;
1582 g_return_val_if_fail (buffer != NULL, NULL);
1583 g_return_val_if_fail (info != NULL, NULL);
1584 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
1586 /* create a new slice */
1587 size = ITEM_SIZE (info);
1588 item = g_slice_alloc (size);
1589 result = &item->meta;
1590 result->info = info;
1591 result->flags = GST_META_FLAG_NONE;
1593 GST_CAT_DEBUG (GST_CAT_BUFFER,
1594 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
1595 g_type_name (info->type), info->size);
1597 /* call the init_func when needed */
1598 if (info->init_func)
1599 if (!info->init_func (result, params, buffer))
1602 /* and add to the list of metadata */
1603 item->next = GST_BUFFER_META (buffer);
1604 GST_BUFFER_META (buffer) = item;
1610 g_slice_free1 (size, item);
1616 * gst_buffer_remove_meta:
1617 * @buffer: a #GstBuffer
1620 * Remove the metadata for @meta on @buffer.
1622 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
1623 * metadata was on @buffer.
1626 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
1628 GstMetaItem *walk, *prev;
1630 g_return_val_if_fail (buffer != NULL, FALSE);
1631 g_return_val_if_fail (meta != NULL, FALSE);
1632 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1633 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
1636 /* find the metadata and delete */
1637 prev = GST_BUFFER_META (buffer);
1638 for (walk = prev; walk; walk = walk->next) {
1639 GstMeta *m = &walk->meta;
1641 const GstMetaInfo *info = meta->info;
1643 /* remove from list */
1644 if (GST_BUFFER_META (buffer) == walk)
1645 GST_BUFFER_META (buffer) = walk->next;
1647 prev->next = walk->next;
1648 /* call free_func if any */
1649 if (info->free_func)
1650 info->free_func (m, buffer);
1652 /* and free the slice */
1653 g_slice_free1 (ITEM_SIZE (info), walk);
1658 return walk != NULL;
1662 * gst_buffer_iterate_meta:
1663 * @buffer: a #GstBuffer
1664 * @state: an opaque state pointer
1666 * Retrieve the next #GstMeta after @current. If @state points
1667 * to %NULL, the first metadata is returned.
1669 * @state will be updated with an opage state pointer
1671 * Returns: The next #GstMeta or %NULL when there are no more items.
1674 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
1678 g_return_val_if_fail (buffer != NULL, NULL);
1679 g_return_val_if_fail (state != NULL, NULL);
1681 meta = (GstMetaItem **) state;
1683 /* state NULL, move to first item */
1684 *meta = GST_BUFFER_META (buffer);
1686 /* state !NULL, move to next item in list */
1687 *meta = (*meta)->next;
1690 return &(*meta)->meta;
1696 * gst_buffer_foreach_meta:
1697 * @buffer: a #GstBuffer
1698 * @func: (scope call): a #GstBufferForeachMetaFunc to call
1699 * @user_data: (closure): user data passed to @func
1701 * Call @func with @user_data for each meta in @buffer.
1703 * @func can modify the passed meta pointer or its contents. The return value
1704 * of @func define if this function returns or if the remaining metadata items
1705 * in the buffer should be skipped.
1708 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
1711 GstMetaItem *walk, *prev, *next;
1713 g_return_if_fail (buffer != NULL);
1714 g_return_if_fail (func != NULL);
1716 /* find the metadata and delete */
1717 prev = GST_BUFFER_META (buffer);
1718 for (walk = prev; walk; walk = next) {
1722 m = new = &walk->meta;
1725 res = func (buffer, &new, user_data);
1728 const GstMetaInfo *info = m->info;
1730 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
1731 g_type_name (info->type));
1733 g_return_if_fail (gst_buffer_is_writable (buffer));
1734 g_return_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED));
1736 /* remove from list */
1737 if (GST_BUFFER_META (buffer) == walk)
1738 GST_BUFFER_META (buffer) = next;
1742 /* call free_func if any */
1743 if (info->free_func)
1744 info->free_func (m, buffer);
1746 /* and free the slice */
1747 g_slice_free1 (ITEM_SIZE (info), walk);