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_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
142 #define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
143 #define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
144 #define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
145 #define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
151 /* the memory blocks */
153 GstMemory *mem[GST_BUFFER_MEM_MAX];
155 /* memory of the buffer when allocated from 1 chunk */
158 /* FIXME, make metadata allocation more efficient by using part of the
165 _is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
167 GstMemory *mcur, *mprv;
168 gboolean have_offset = FALSE;
173 for (i = 0; i < len; i++) {
181 /* check if memory is contiguous */
182 if (!gst_memory_is_span (mprv, mcur, &poffs))
189 *parent = mprv->parent;
199 _get_merged_memory (GstBuffer * buffer, guint idx, guint length)
201 GstMemory **mem, *result;
203 mem = GST_BUFFER_MEM_ARRAY (buffer);
205 if (G_UNLIKELY (length == 0)) {
207 } else if (G_LIKELY (length == 1)) {
208 result = gst_memory_ref (mem[idx]);
210 GstMemory *parent = NULL;
211 gsize size, poffset = 0;
213 size = gst_buffer_get_size (buffer);
215 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
217 if (parent->flags & GST_MEMORY_FLAG_NO_SHARE) {
218 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
219 result = gst_memory_copy (parent, poffset, size);
221 result = gst_memory_share (parent, poffset, size);
224 gsize i, tocopy, left;
225 GstMapInfo sinfo, dinfo;
228 result = gst_allocator_alloc (NULL, size, NULL);
229 gst_memory_map (result, &dinfo, GST_MAP_WRITE);
234 for (i = idx; i < length && left > 0; i++) {
235 gst_memory_map (mem[i], &sinfo, GST_MAP_READ);
236 tocopy = MIN (sinfo.size, left);
237 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
238 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
239 tocopy, result, mem[i]);
240 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
243 gst_memory_unmap (mem[i], &sinfo);
245 gst_memory_unmap (result, &dinfo);
252 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
258 GST_LOG ("buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer,
261 /* unref old memory */
262 for (i = idx; i < end; i++)
263 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
266 /* replace with single memory */
267 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
273 g_memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
274 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
276 GST_BUFFER_MEM_LEN (buffer) = len - length;
280 _memory_add (GstBuffer * buffer, guint idx, GstMemory * mem)
282 guint i, len = GST_BUFFER_MEM_LEN (buffer);
284 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
285 /* too many buffer, span them. */
286 /* FIXME, there is room for improvement here: We could only try to merge
287 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
288 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
289 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
291 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
292 /* we now have 1 single spanned buffer */
299 for (i = len; i > idx; i--) {
300 /* move buffers to insert, FIXME, we need to insert first and then merge */
301 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
303 /* and insert the new buffer */
304 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
305 GST_BUFFER_MEM_LEN (buffer) = len + 1;
308 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
311 _priv_gst_buffer_initialize (void)
313 _gst_buffer_type = gst_buffer_get_type ();
317 * gst_buffer_copy_into:
318 * @dest: a destination #GstBuffer
319 * @src: a source #GstBuffer
320 * @flags: flags indicating what metadata fields should be copied.
321 * @offset: offset to copy from
322 * @size: total size to copy. If -1, all data is copied.
324 * Copies the information from @src into @dest.
326 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
327 * the memory from @src will be appended to @dest.
329 * @flags indicate which fields will be copied.
332 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
333 GstBufferCopyFlags flags, gsize offset, gsize size)
337 gboolean region = FALSE;
339 g_return_if_fail (dest != NULL);
340 g_return_if_fail (src != NULL);
342 /* nothing to copy if the buffers are the same */
343 if (G_UNLIKELY (dest == src))
346 g_return_if_fail (gst_buffer_is_writable (dest));
348 bufsize = gst_buffer_get_size (src);
349 g_return_if_fail (bufsize >= offset);
353 size = bufsize - offset;
356 g_return_if_fail (bufsize >= offset + size);
358 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
359 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
362 if (flags & GST_BUFFER_COPY_FLAGS) {
364 GST_MINI_OBJECT_FLAGS (dest) = GST_MINI_OBJECT_FLAGS (src);
367 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
369 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
370 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
371 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
372 if (size == bufsize) {
373 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
374 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
377 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
378 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
379 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
380 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
381 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
385 if (flags & GST_BUFFER_COPY_MEMORY) {
387 gsize skip, left, len, i, bsize;
389 len = GST_BUFFER_MEM_LEN (src);
393 /* copy and make regions of the memory */
394 for (i = 0; i < len && left > 0; i++) {
395 mem = GST_BUFFER_MEM_PTR (src, i);
396 bsize = gst_memory_get_sizes (mem, NULL, NULL);
399 /* don't copy buffer */
404 tocopy = MIN (bsize - skip, left);
405 if (mem->flags & GST_MEMORY_FLAG_NO_SHARE) {
406 /* no share, always copy then */
407 mem = gst_memory_copy (mem, skip, tocopy);
409 } else if (tocopy < bsize) {
410 /* we need to clip something */
411 mem = gst_memory_share (mem, skip, tocopy);
414 mem = gst_memory_ref (mem);
416 _memory_add (dest, -1, mem);
420 if (flags & GST_BUFFER_COPY_MERGE) {
421 len = GST_BUFFER_MEM_LEN (dest);
422 _replace_memory (dest, len, 0, len, _get_merged_memory (dest, 0, len));
426 if (flags & GST_BUFFER_COPY_META) {
427 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
428 GstMeta *meta = &walk->meta;
429 const GstMetaInfo *info = meta->info;
431 if (info->transform_func) {
432 GstMetaTransformCopy copy_data;
434 copy_data.region = region;
435 copy_data.offset = offset;
436 copy_data.size = size;
438 info->transform_func (dest, meta, src,
439 _gst_meta_transform_copy, ©_data);
446 _gst_buffer_copy (GstBuffer * buffer)
450 g_return_val_if_fail (buffer != NULL, NULL);
452 /* create a fresh new buffer */
453 copy = gst_buffer_new ();
455 /* we simply copy everything from our parent */
456 gst_buffer_copy_into (copy, buffer, GST_BUFFER_COPY_ALL, 0, -1);
461 /* the default dispose function revives the buffer and returns it to the
462 * pool when there is a pool */
464 _gst_buffer_dispose (GstBuffer * buffer)
468 /* no pool, do free */
469 if ((pool = buffer->pool) == NULL)
472 /* keep the buffer alive */
473 gst_buffer_ref (buffer);
474 /* return the buffer to the pool */
475 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
476 gst_buffer_pool_release_buffer (pool, buffer);
482 _gst_buffer_free (GstBuffer * buffer)
484 GstMetaItem *walk, *next;
488 g_return_if_fail (buffer != NULL);
490 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
493 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
494 GstMeta *meta = &walk->meta;
495 const GstMetaInfo *info = meta->info;
497 /* call free_func if any */
499 info->free_func (meta, buffer);
502 /* and free the slice */
503 g_slice_free1 (ITEM_SIZE (info), walk);
506 /* get the size, when unreffing the memory, we could also unref the buffer
508 msize = GST_MINI_OBJECT_SIZE (buffer);
510 /* free our memory */
511 len = GST_BUFFER_MEM_LEN (buffer);
512 for (i = 0; i < len; i++)
513 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
515 /* we set msize to 0 when the buffer is part of the memory block */
517 g_slice_free1 (msize, buffer);
519 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
523 gst_buffer_init (GstBufferImpl * buffer, gsize size)
525 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), _gst_buffer_type, size);
527 buffer->buffer.mini_object.copy =
528 (GstMiniObjectCopyFunction) _gst_buffer_copy;
529 buffer->buffer.mini_object.dispose =
530 (GstMiniObjectDisposeFunction) _gst_buffer_dispose;
531 buffer->buffer.mini_object.free =
532 (GstMiniObjectFreeFunction) _gst_buffer_free;
534 GST_BUFFER (buffer)->pool = NULL;
535 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
536 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
537 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
538 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
539 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
541 GST_BUFFER_MEM_LEN (buffer) = 0;
542 GST_BUFFER_META (buffer) = NULL;
548 * Creates a newly allocated buffer without any data.
552 * Returns: (transfer full): the new #GstBuffer.
555 gst_buffer_new (void)
557 GstBufferImpl *newbuf;
559 newbuf = g_slice_new (GstBufferImpl);
560 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
562 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
564 return GST_BUFFER_CAST (newbuf);
568 * gst_buffer_new_allocate:
569 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or NULL to use the
571 * @size: the size in bytes of the new buffer's data.
572 * @params: (transfer none) (allow-none): optional parameters
574 * Tries to create a newly allocated buffer with data of the given size and
575 * extra parameters from @allocator. If the requested amount of memory can't be
576 * allocated, NULL will be returned. The allocated buffer memory is not cleared.
578 * When @allocator is NULL, the default memory allocator will be used.
580 * Note that when @size == 0, the buffer will not have memory associated with it.
584 * Returns: (transfer full): a new #GstBuffer, or NULL if the memory couldn't
588 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
589 GstAllocationParams * params)
600 mem = gst_allocator_alloc (allocator, size, params);
601 if (G_UNLIKELY (mem == NULL))
607 newbuf = gst_buffer_new ();
610 _memory_add (newbuf, -1, mem);
612 GST_CAT_LOG (GST_CAT_BUFFER,
613 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
618 asize = sizeof (GstBufferImpl) + size;
619 data = g_slice_alloc (asize);
620 if (G_UNLIKELY (data == NULL))
623 newbuf = GST_BUFFER_CAST (data);
625 gst_buffer_init ((GstBufferImpl *) data, asize);
627 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
629 _memory_add (newbuf, -1, mem);
634 /* allocate memory and buffer, it might be interesting to do this but there
635 * are many complications. We need to keep the memory mapped to access the
636 * buffer fields and the memory for the buffer might be just very slow. We
637 * also need to do some more magic to get the alignment right. */
638 asize = sizeof (GstBufferImpl) + size;
639 mem = gst_allocator_alloc (allocator, asize, align);
640 if (G_UNLIKELY (mem == NULL))
643 /* map the data part and init the buffer in it, set the buffer size to 0 so
644 * that a finalize won't free the buffer */
645 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
646 gst_buffer_init ((GstBufferImpl *) data, 0);
647 gst_memory_unmap (mem);
649 /* strip off the buffer */
650 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
652 newbuf = GST_BUFFER_CAST (data);
653 GST_BUFFER_BUFMEM (newbuf) = mem;
656 _memory_add (newbuf, -1, gst_memory_ref (mem));
664 GST_CAT_WARNING (GST_CAT_BUFFER,
665 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
671 * gst_buffer_new_wrapped_full:
672 * @flags: #GstMemoryFlags
673 * @data: data to wrap
674 * @maxsize: allocated size of @data
675 * @offset: offset in @data
676 * @size: size of valid data
677 * @user_data: user_data
678 * @notify: called with @user_data when the memory is freed
680 * Allocate a new buffer that wraps the given memory. @data must point to
681 * @maxsize of memory, the wrapped buffer will have the region from @offset and
684 * When the buffer is destroyed, @notify will be called with @user_data.
686 * The prefix/padding must be filled with 0 if @flags contains
687 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
689 * Returns: (transfer full): a new #GstBuffer
692 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
693 gsize maxsize, gsize offset, gsize size, gpointer user_data,
694 GDestroyNotify notify)
698 newbuf = gst_buffer_new ();
699 gst_buffer_append_memory (newbuf,
700 gst_memory_new_wrapped (flags, data, maxsize, offset, size,
707 * gst_buffer_new_wrapped:
708 * @data: data to wrap
709 * @size: allocated size of @data
711 * Creates a new buffer that wraps the given @data. The memory will be freed
712 * with g_free and will be marked writable.
716 * Returns: (transfer full): a new #GstBuffer
719 gst_buffer_new_wrapped (gpointer data, gsize size)
721 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
725 * gst_buffer_n_memory:
726 * @buffer: a #GstBuffer.
728 * Get the amount of memory blocks that this buffer has.
730 * Returns: (transfer full): the amount of memory block in this buffer.
733 gst_buffer_n_memory (GstBuffer * buffer)
735 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
737 return GST_BUFFER_MEM_LEN (buffer);
741 * gst_buffer_insert_memory:
742 * @buffer: a #GstBuffer.
743 * @idx: the index to add the memory at, or -1 to append it to the end
744 * @mem: (transfer full): a #GstMemory.
746 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
747 * of @mem and thus doesn't increase its refcount.
750 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
752 g_return_if_fail (GST_IS_BUFFER (buffer));
753 g_return_if_fail (gst_buffer_is_writable (buffer));
754 g_return_if_fail (mem != NULL);
755 g_return_if_fail (idx == -1 ||
756 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
758 _memory_add (buffer, idx, mem);
762 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
765 GstMemory *mem, *mapped;
767 mem = GST_BUFFER_MEM_PTR (buffer, idx);
769 mapped = gst_memory_make_mapped (mem, info, flags);
774 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
775 gst_memory_unref (mem);
782 * gst_buffer_peek_memory:
783 * @buffer: a #GstBuffer.
786 * Get the memory block at @idx in @buffer. The memory block stays valid until
787 * the memory block in @buffer is removed, replaced or merged, typically with
788 * any call that modifies the memory in @buffer.
790 * Since this call does not influence the refcount of the memory,
791 * gst_memory_is_exclusive() can be used to check if @buffer is the sole owner
792 * of the returned memory.
794 * Returns: (transfer none): the #GstMemory at @idx.
797 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
801 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
802 len = GST_BUFFER_MEM_LEN (buffer);
803 g_return_val_if_fail (idx < len, NULL);
805 return GST_BUFFER_MEM_PTR (buffer, idx);
809 * gst_buffer_get_memory_range:
810 * @buffer: a #GstBuffer.
814 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
815 * be merged into one large #GstMemory.
817 * If @length is -1, all memory starting from @idx is merged.
819 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
820 * blocks starting at @idx. Use gst_memory_unref () after usage.
823 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
827 GST_DEBUG ("idx %u, length %d", idx, length);
829 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
830 len = GST_BUFFER_MEM_LEN (buffer);
831 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
832 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
837 return _get_merged_memory (buffer, idx, length);
841 * gst_buffer_replace_memory_range:
842 * @buffer: a #GstBuffer.
844 * @length: a length should not be 0
845 * @mem: (transfer full): a #GstMemory
847 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
849 * If @length is -1, all memory starting from @idx will be removed and
850 * replaced with @mem.
852 * @buffer should be writable.
855 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
860 g_return_if_fail (GST_IS_BUFFER (buffer));
861 g_return_if_fail (gst_buffer_is_writable (buffer));
862 len = GST_BUFFER_MEM_LEN (buffer);
863 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
864 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
869 _replace_memory (buffer, len, idx, length, mem);
873 * gst_buffer_remove_memory_range:
874 * @buffer: a #GstBuffer.
878 * Remove @length memory blocks in @buffer starting from @idx.
880 * @length can be -1, in which case all memory starting from @idx is removed.
883 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
887 g_return_if_fail (GST_IS_BUFFER (buffer));
888 g_return_if_fail (gst_buffer_is_writable (buffer));
890 len = GST_BUFFER_MEM_LEN (buffer);
891 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
892 (length == -1 && idx < len) || length + idx <= len);
897 _replace_memory (buffer, len, idx, length, NULL);
901 * gst_buffer_find_memory:
902 * @buffer: a #GstBuffer.
905 * @idx: (out): pointer to index
906 * @length: (out): pointer to length
907 * @skip: (out): pointer to skip
909 * Find the memory blocks that span @size bytes starting from @offset
912 * When this function returns %TRUE, @idx will contain the index of the first
913 * memory bock where the byte for @offset can be found and @length contains the
914 * number of memory blocks containing the @size remaining bytes. @skip contains
915 * the number of bytes to skip in the memory bock at @idx to get to the byte
918 * @size can be -1 to get all the memory blocks after @idx.
920 * Returns: %TRUE when @size bytes starting from @offset could be found in
921 * @buffer and @idx, @length and @skip will be filled.
924 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
925 guint * idx, guint * length, gsize * skip)
929 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
930 g_return_val_if_fail (idx != NULL, FALSE);
931 g_return_val_if_fail (length != NULL, FALSE);
932 g_return_val_if_fail (skip != NULL, FALSE);
934 len = GST_BUFFER_MEM_LEN (buffer);
937 for (i = 0; i < len; i++) {
941 mem = GST_BUFFER_MEM_PTR (buffer, i);
942 s = gst_memory_get_sizes (mem, NULL, NULL);
945 /* block before offset, or empty block, skip */
948 /* block after offset */
950 /* first block, remember index and offset */
954 /* return remaining blocks */
961 /* count the amount of found bytes */
964 /* we have enough bytes */
965 *length = i - *idx + 1;
974 * gst_buffer_get_sizes_range:
975 * @buffer: a #GstBuffer.
978 * @offset: a pointer to the offset
979 * @maxsize: a pointer to the maxsize
981 * Get the total size of @length memory blocks stating from @idx in @buffer.
983 * When not %NULL, @offset will contain the offset of the data in the
984 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
985 * and @offset and the amount of extra padding on the memory block at @idx +
987 * @offset and @maxsize can be used to resize the buffer memory blocks with
988 * gst_buffer_resize_range().
990 * Returns: total size @length memory blocks starting at @idx in @buffer.
993 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
994 gsize * offset, gsize * maxsize)
1000 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1001 len = GST_BUFFER_MEM_LEN (buffer);
1002 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1003 (length == -1 && idx < len) || (length + idx <= len), 0);
1008 if (G_LIKELY (length == 1)) {
1010 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1011 size = gst_memory_get_sizes (mem, offset, maxsize);
1017 size = offs = extra = 0;
1018 for (i = idx; i < end; i++) {
1021 mem = GST_BUFFER_MEM_PTR (buffer, i);
1022 s = gst_memory_get_sizes (mem, &o, &ms);
1026 /* first size, take accumulated data before as the offset */
1030 /* save the amount of data after this block */
1031 extra = ms - (o + s);
1033 /* empty block, add as extra */
1040 *maxsize = offs + size + extra;
1046 * gst_buffer_resize_range:
1047 * @buffer: a #GstBuffer.
1050 * @offset: the offset adjustement
1051 * @size: the new size or -1 to just adjust the offset
1053 * Set the total size of the @length memory blocks starting at @idx in
1057 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1058 gssize offset, gssize size)
1061 gsize bsize, bufsize, bufoffs, bufmax;
1064 g_return_if_fail (gst_buffer_is_writable (buffer));
1065 g_return_if_fail (size >= -1);
1066 len = GST_BUFFER_MEM_LEN (buffer);
1067 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1068 (length == -1 && idx < len) || (length + idx <= len));
1073 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1075 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1076 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1077 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1079 /* we can't go back further than the current offset or past the end of the
1081 g_return_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1082 && bufoffs + offset <= bufmax));
1084 g_return_if_fail (bufsize >= offset);
1085 size = bufsize - offset;
1087 g_return_if_fail (bufmax >= bufoffs + offset + size);
1090 if (offset == 0 && size == bufsize)
1095 for (i = idx; i < end; i++) {
1098 mem = GST_BUFFER_MEM_PTR (buffer, i);
1099 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1102 /* last buffer always gets resized to the remaining size */
1105 /* shrink buffers before the offset */
1106 else if ((gssize) bsize <= offset) {
1108 noffs = offset - bsize;
1111 /* clip other buffers */
1113 left = MIN (bsize - offset, size);
1115 if (offset != 0 || left != bsize) {
1116 if (gst_memory_is_exclusive (mem)) {
1117 gst_memory_resize (mem, offset, left);
1121 if (mem->flags & GST_MEMORY_FLAG_NO_SHARE)
1122 tmp = gst_memory_copy (mem, offset, left);
1124 tmp = gst_memory_share (mem, offset, left);
1126 gst_memory_unref (mem);
1133 GST_BUFFER_MEM_PTR (buffer, i) = mem;
1138 * gst_buffer_map_range:
1139 * @buffer: a #GstBuffer.
1142 * @info: (out): info about the mapping
1143 * @flags: flags for the mapping
1145 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1146 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1147 * from @idx are merged and mapped.
1148 * @flags describe the desired access of the memory. When @flags is
1149 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1150 * gst_buffer_is_writable()).
1152 * When @buffer is writable but the memory isn't, a writable copy will
1153 * automatically be created and returned. The readonly copy of the buffer memory
1154 * will then also be replaced with this writable copy.
1156 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1158 * Returns: (transfer full): %TRUE if the map succeeded and @info contains valid
1162 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1163 GstMapInfo * info, GstMapFlags flags)
1165 GstMemory *mem, *nmem;
1166 gboolean write, writable;
1169 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1170 g_return_val_if_fail (info != NULL, FALSE);
1171 len = GST_BUFFER_MEM_LEN (buffer);
1172 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1173 (length == -1 && idx < len) || (length > 0
1174 && length + idx <= len), FALSE);
1176 write = (flags & GST_MAP_WRITE) != 0;
1177 writable = gst_buffer_is_writable (buffer);
1179 /* check if we can write when asked for write access */
1180 if (G_UNLIKELY (write && !writable))
1186 mem = _get_merged_memory (buffer, idx, length);
1187 if (G_UNLIKELY (mem == NULL))
1190 /* now try to map */
1191 nmem = gst_memory_make_mapped (mem, info, flags);
1192 if (G_UNLIKELY (nmem == NULL))
1195 /* if we merged or when the map returned a different memory, we try to replace
1196 * the memory in the buffer */
1197 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1198 /* if the buffer is writable, replace the memory */
1200 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1203 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1204 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1213 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1214 g_critical ("write map requested on non-writable buffer");
1219 /* empty buffer, we need to return NULL */
1220 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1221 info->memory = NULL;
1229 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1236 * @buffer: a #GstBuffer.
1237 * @info: a #GstMapInfo
1239 * Release the memory previously mapped with gst_buffer_map().
1242 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1244 g_return_if_fail (GST_IS_BUFFER (buffer));
1245 g_return_if_fail (info != NULL);
1247 /* we need to check for NULL, it is possible that we tried to map a buffer
1248 * without memory and we should be able to unmap that fine */
1249 if (G_LIKELY (info->memory)) {
1250 gst_memory_unmap (info->memory, info);
1251 gst_memory_unref (info->memory);
1257 * @buffer: a #GstBuffer.
1258 * @offset: the offset to fill
1259 * @src: the source address
1260 * @size: the size to fill
1262 * Copy @size bytes from @src to @buffer at @offset.
1264 * Returns: The amount of bytes copied. This value can be lower than @size
1265 * when @buffer did not contain enough data.
1268 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1272 const guint8 *ptr = src;
1274 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1275 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1276 g_return_val_if_fail (src != NULL, 0);
1278 len = GST_BUFFER_MEM_LEN (buffer);
1281 for (i = 0; i < len && left > 0; i++) {
1286 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1287 if (info.size > offset) {
1288 /* we have enough */
1289 tocopy = MIN (info.size - offset, left);
1290 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1295 /* offset past buffer, skip */
1296 offset -= info.size;
1298 gst_memory_unmap (mem, &info);
1304 * gst_buffer_extract:
1305 * @buffer: a #GstBuffer.
1306 * @offset: the offset to extract
1307 * @dest: the destination address
1308 * @size: the size to extract
1310 * Copy @size bytes starting from @offset in @buffer to @dest.
1312 * Returns: The amount of bytes extracted. This value can be lower than @size
1313 * when @buffer did not contain enough data.
1316 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1321 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1322 g_return_val_if_fail (dest != NULL, 0);
1324 len = GST_BUFFER_MEM_LEN (buffer);
1327 for (i = 0; i < len && left > 0; i++) {
1332 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1333 if (info.size > offset) {
1334 /* we have enough */
1335 tocopy = MIN (info.size - offset, left);
1336 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1341 /* offset past buffer, skip */
1342 offset -= info.size;
1344 gst_memory_unmap (mem, &info);
1350 * gst_buffer_memcmp:
1351 * @buffer: a #GstBuffer.
1352 * @offset: the offset in @buffer
1353 * @mem: the memory to compare
1354 * @size: the size to compare
1356 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1358 * Returns: 0 if the memory is equal.
1361 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1365 const guint8 *ptr = mem;
1368 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1369 g_return_val_if_fail (mem != NULL, 0);
1371 len = GST_BUFFER_MEM_LEN (buffer);
1373 for (i = 0; i < len && size > 0 && res == 0; i++) {
1378 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1379 if (info.size > offset) {
1380 /* we have enough */
1381 tocmp = MIN (info.size - offset, size);
1382 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1387 /* offset past buffer, skip */
1388 offset -= info.size;
1390 gst_memory_unmap (mem, &info);
1396 * gst_buffer_memset:
1397 * @buffer: a #GstBuffer.
1398 * @offset: the offset in @buffer
1399 * @val: the value to set
1400 * @size: the size to set
1402 * Fill @buf with @size bytes with @val starting from @offset.
1404 * Returns: The amount of bytes filled. This value can be lower than @size
1405 * when @buffer did not contain enough data.
1408 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1412 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1413 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1415 len = GST_BUFFER_MEM_LEN (buffer);
1418 for (i = 0; i < len && left > 0; i++) {
1423 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1424 if (info.size > offset) {
1425 /* we have enough */
1426 toset = MIN (info.size - offset, left);
1427 memset ((guint8 *) info.data + offset, val, toset);
1431 /* offset past buffer, skip */
1432 offset -= info.size;
1434 gst_memory_unmap (mem, &info);
1440 * gst_buffer_copy_region:
1441 * @parent: a #GstBuffer.
1442 * @flags: the #GstBufferCopyFlags
1443 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1445 * @size: the size of the new #GstBuffer sub-buffer, in bytes.
1447 * Creates a sub-buffer from @parent at @offset and @size.
1448 * This sub-buffer uses the actual memory space of the parent buffer.
1449 * This function will copy the offset and timestamp fields when the
1450 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1451 * #GST_BUFFER_OFFSET_NONE.
1452 * If @offset equals 0 and @size equals the total size of @buffer, the
1453 * duration and offset end fields are also copied. If not they will be set
1454 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1458 * Returns: (transfer full): the new #GstBuffer or NULL if the arguments were
1462 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1463 gsize offset, gsize size)
1467 g_return_val_if_fail (buffer != NULL, NULL);
1469 /* create the new buffer */
1470 copy = gst_buffer_new ();
1472 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1473 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1475 gst_buffer_copy_into (copy, buffer, flags, offset, size);
1481 * gst_buffer_append:
1482 * @buf1: (transfer full): the first source #GstBuffer to append.
1483 * @buf2: (transfer full): the second source #GstBuffer to append.
1485 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1486 * concatenation of the memory of @buf1 and @buf2.
1488 * Returns: (transfer full): the new #GstBuffer that contains the memory
1489 * of the two source buffers.
1492 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1496 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1497 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1499 buf1 = gst_buffer_make_writable (buf1);
1500 buf2 = gst_buffer_make_writable (buf2);
1502 len = GST_BUFFER_MEM_LEN (buf2);
1503 for (i = 0; i < len; i++) {
1506 mem = GST_BUFFER_MEM_PTR (buf2, i);
1507 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1508 _memory_add (buf1, -1, mem);
1511 /* we can calculate the duration too. Also make sure we're not messing
1512 * with invalid DURATIONS */
1513 if (GST_BUFFER_DURATION_IS_VALID (buf1) &&
1514 GST_BUFFER_DURATION_IS_VALID (buf2)) {
1516 GST_BUFFER_DURATION (buf1) += GST_BUFFER_DURATION (buf2);
1518 if (GST_BUFFER_OFFSET_END_IS_VALID (buf2)) {
1519 /* set offset_end */
1520 GST_BUFFER_OFFSET_END (buf1) = GST_BUFFER_OFFSET_END (buf2);
1523 GST_BUFFER_MEM_LEN (buf2) = 0;
1524 gst_buffer_unref (buf2);
1530 * gst_buffer_get_meta:
1531 * @buffer: a #GstBuffer
1532 * @api: the #GType of an API
1534 * Get the metadata for @api on buffer. When there is no such
1535 * metadata, NULL is returned.
1537 * Returns: the metadata for @api on @buffer.
1540 gst_buffer_get_meta (GstBuffer * buffer, GType api)
1543 GstMeta *result = NULL;
1545 g_return_val_if_fail (buffer != NULL, NULL);
1546 g_return_val_if_fail (api != 0, NULL);
1548 /* find GstMeta of the requested API */
1549 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
1550 GstMeta *meta = &item->meta;
1551 if (meta->info->api == api) {
1560 * gst_buffer_add_meta:
1561 * @buffer: a #GstBuffer
1562 * @info: a #GstMetaInfo
1563 * @params: params for @info
1565 * Add metadata for @info to @buffer using the parameters in @params.
1567 * Returns: (transfer none): the metadata for the api in @info on @buffer.
1570 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
1574 GstMeta *result = NULL;
1577 g_return_val_if_fail (buffer != NULL, NULL);
1578 g_return_val_if_fail (info != NULL, NULL);
1579 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
1581 /* create a new slice */
1582 size = ITEM_SIZE (info);
1583 item = g_slice_alloc (size);
1584 result = &item->meta;
1585 result->info = info;
1586 result->flags = GST_META_FLAG_NONE;
1588 GST_CAT_DEBUG (GST_CAT_BUFFER,
1589 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
1590 g_type_name (info->type), info->size);
1592 /* call the init_func when needed */
1593 if (info->init_func)
1594 if (!info->init_func (result, params, buffer))
1597 /* and add to the list of metadata */
1598 item->next = GST_BUFFER_META (buffer);
1599 GST_BUFFER_META (buffer) = item;
1605 g_slice_free1 (size, item);
1611 * gst_buffer_remove_meta:
1612 * @buffer: a #GstBuffer
1615 * Remove the metadata for @meta on @buffer.
1617 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
1618 * metadata was on @buffer.
1621 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
1623 GstMetaItem *walk, *prev;
1625 g_return_val_if_fail (buffer != NULL, FALSE);
1626 g_return_val_if_fail (meta != NULL, FALSE);
1627 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1628 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
1631 /* find the metadata and delete */
1632 prev = GST_BUFFER_META (buffer);
1633 for (walk = prev; walk; walk = walk->next) {
1634 GstMeta *m = &walk->meta;
1636 const GstMetaInfo *info = meta->info;
1638 /* remove from list */
1639 if (GST_BUFFER_META (buffer) == walk)
1640 GST_BUFFER_META (buffer) = walk->next;
1642 prev->next = walk->next;
1643 /* call free_func if any */
1644 if (info->free_func)
1645 info->free_func (m, buffer);
1647 /* and free the slice */
1648 g_slice_free1 (ITEM_SIZE (info), walk);
1653 return walk != NULL;
1657 * gst_buffer_iterate_meta:
1658 * @buffer: a #GstBuffer
1659 * @state: an opaque state pointer
1661 * Retrieve the next #GstMeta after @current. If @state points
1662 * to %NULL, the first metadata is returned.
1664 * @state will be updated with an opage state pointer
1666 * Returns: The next #GstMeta or %NULL when there are no more items.
1669 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
1673 g_return_val_if_fail (buffer != NULL, NULL);
1674 g_return_val_if_fail (state != NULL, NULL);
1676 meta = (GstMetaItem **) state;
1678 /* state NULL, move to first item */
1679 *meta = GST_BUFFER_META (buffer);
1681 /* state !NULL, move to next item in list */
1682 *meta = (*meta)->next;
1685 return &(*meta)->meta;
1691 * gst_buffer_foreach_meta:
1692 * @buffer: a #GstBuffer
1693 * @func: (scope call): a #GstBufferForeachMetaFunc to call
1694 * @user_data: (closure): user data passed to @func
1696 * Call @func with @user_data for each meta in @buffer.
1698 * @func can modify the passed meta pointer or its contents. The return value
1699 * of @func define if this function returns or if the remaining metadata items
1700 * in the buffer should be skipped.
1703 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
1706 GstMetaItem *walk, *prev, *next;
1708 g_return_if_fail (buffer != NULL);
1709 g_return_if_fail (func != NULL);
1711 /* find the metadata and delete */
1712 prev = GST_BUFFER_META (buffer);
1713 for (walk = prev; walk; walk = next) {
1717 m = new = &walk->meta;
1720 res = func (buffer, &new, user_data);
1723 const GstMetaInfo *info = m->info;
1725 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
1726 g_type_name (info->type));
1728 g_return_if_fail (gst_buffer_is_writable (buffer));
1729 g_return_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED));
1731 /* remove from list */
1732 if (GST_BUFFER_META (buffer) == walk)
1733 GST_BUFFER_META (buffer) = next;
1737 /* call free_func if any */
1738 if (info->free_func)
1739 info->free_func (m, buffer);
1741 /* and free the slice */
1742 g_slice_free1 (ITEM_SIZE (info), walk);