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., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, 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 = NULL;
206 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %u", buffer, idx,
209 mem = GST_BUFFER_MEM_ARRAY (buffer);
211 if (G_UNLIKELY (length == 0)) {
213 } else if (G_LIKELY (length == 1)) {
214 result = gst_memory_ref (mem[idx]);
216 GstMemory *parent = NULL;
217 gsize size, poffset = 0;
219 size = gst_buffer_get_size (buffer);
221 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
222 if (!GST_MEMORY_IS_NO_SHARE (parent))
223 result = gst_memory_share (parent, poffset, size);
225 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
226 result = gst_memory_copy (parent, poffset, size);
229 g_return_val_if_fail (result != NULL, NULL);
231 gsize i, tocopy, left;
232 GstMapInfo sinfo, dinfo;
235 result = gst_allocator_alloc (NULL, size, NULL);
236 gst_memory_map (result, &dinfo, GST_MAP_WRITE);
241 for (i = idx; i < length && left > 0; i++) {
242 gst_memory_map (mem[i], &sinfo, GST_MAP_READ);
243 tocopy = MIN (sinfo.size, left);
244 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
245 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
246 tocopy, result, mem[i]);
247 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
250 gst_memory_unmap (mem[i], &sinfo);
252 gst_memory_unmap (result, &dinfo);
259 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
266 GST_CAT_LOG (GST_CAT_BUFFER,
267 "buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
270 /* unref old memory */
271 for (i = idx; i < end; i++) {
272 GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
274 gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
275 gst_memory_unref (old);
279 /* replace with single memory */
280 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
281 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
287 g_memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
288 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
290 GST_BUFFER_MEM_LEN (buffer) = len - length;
294 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem, gboolean lock)
296 guint i, len = GST_BUFFER_MEM_LEN (buffer);
298 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p, lock %d", buffer,
301 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
302 /* too many buffer, span them. */
303 /* FIXME, there is room for improvement here: We could only try to merge
304 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
305 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
306 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
308 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
309 /* we now have 1 single spanned buffer */
316 for (i = len; i > idx; i--) {
317 /* move buffers to insert, FIXME, we need to insert first and then merge */
318 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
320 /* and insert the new buffer */
322 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
323 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
324 GST_BUFFER_MEM_LEN (buffer) = len + 1;
327 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
330 _priv_gst_buffer_initialize (void)
332 _gst_buffer_type = gst_buffer_get_type ();
336 * gst_buffer_copy_into:
337 * @dest: a destination #GstBuffer
338 * @src: a source #GstBuffer
339 * @flags: flags indicating what metadata fields should be copied.
340 * @offset: offset to copy from
341 * @size: total size to copy. If -1, all data is copied.
343 * Copies the information from @src into @dest.
345 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
346 * the memory from @src will be appended to @dest.
348 * @flags indicate which fields will be copied.
351 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
352 GstBufferCopyFlags flags, gsize offset, gsize size)
356 gboolean region = FALSE;
358 g_return_if_fail (dest != NULL);
359 g_return_if_fail (src != NULL);
361 /* nothing to copy if the buffers are the same */
362 if (G_UNLIKELY (dest == src))
365 g_return_if_fail (gst_buffer_is_writable (dest));
367 bufsize = gst_buffer_get_size (src);
368 g_return_if_fail (bufsize >= offset);
372 size = bufsize - offset;
375 g_return_if_fail (bufsize >= offset + size);
377 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
378 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
381 if (flags & GST_BUFFER_COPY_FLAGS) {
383 GST_MINI_OBJECT_FLAGS (dest) = GST_MINI_OBJECT_FLAGS (src);
386 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
388 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
389 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
390 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
391 if (size == bufsize) {
392 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
393 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
396 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
397 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
398 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
399 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
400 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
404 if (flags & GST_BUFFER_COPY_MEMORY) {
406 gsize skip, left, len, i, bsize;
409 deep = flags & GST_BUFFER_COPY_DEEP;
411 len = GST_BUFFER_MEM_LEN (src);
415 /* copy and make regions of the memory */
416 for (i = 0; i < len && left > 0; i++) {
417 mem = GST_BUFFER_MEM_PTR (src, i);
418 bsize = gst_memory_get_sizes (mem, NULL, NULL);
421 /* don't copy buffer */
426 tocopy = MIN (bsize - skip, left);
428 if (tocopy < bsize && (!deep || !GST_MEMORY_IS_NO_SHARE (mem))) {
429 /* we need to clip something */
430 mem = gst_memory_share (mem, skip, tocopy);
434 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!mem && tocopy < bsize)) {
435 /* deep copy or we're not allowed to share this memory
436 * between buffers, always copy then */
437 mem = gst_memory_copy (mem, skip, tocopy);
440 mem = gst_memory_ref (mem);
443 g_return_if_fail (mem != NULL);
445 _memory_add (dest, -1, mem, TRUE);
449 if (flags & GST_BUFFER_COPY_MERGE) {
450 len = GST_BUFFER_MEM_LEN (dest);
451 _replace_memory (dest, len, 0, len, _get_merged_memory (dest, 0, len));
455 if (flags & GST_BUFFER_COPY_META) {
456 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
457 GstMeta *meta = &walk->meta;
458 const GstMetaInfo *info = meta->info;
460 if (info->transform_func) {
461 GstMetaTransformCopy copy_data;
463 copy_data.region = region;
464 copy_data.offset = offset;
465 copy_data.size = size;
467 info->transform_func (dest, meta, src,
468 _gst_meta_transform_copy, ©_data);
475 _gst_buffer_copy (GstBuffer * buffer)
479 g_return_val_if_fail (buffer != NULL, NULL);
481 /* create a fresh new buffer */
482 copy = gst_buffer_new ();
484 /* we simply copy everything from our parent */
485 gst_buffer_copy_into (copy, buffer, GST_BUFFER_COPY_ALL, 0, -1);
490 /* the default dispose function revives the buffer and returns it to the
491 * pool when there is a pool */
493 _gst_buffer_dispose (GstBuffer * buffer)
497 /* no pool, do free */
498 if ((pool = buffer->pool) == NULL)
501 /* keep the buffer alive */
502 gst_buffer_ref (buffer);
503 /* return the buffer to the pool */
504 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
505 gst_buffer_pool_release_buffer (pool, buffer);
511 _gst_buffer_free (GstBuffer * buffer)
513 GstMetaItem *walk, *next;
517 g_return_if_fail (buffer != NULL);
519 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
522 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
523 GstMeta *meta = &walk->meta;
524 const GstMetaInfo *info = meta->info;
526 /* call free_func if any */
528 info->free_func (meta, buffer);
531 /* and free the slice */
532 g_slice_free1 (ITEM_SIZE (info), walk);
535 /* get the size, when unreffing the memory, we could also unref the buffer
537 msize = GST_BUFFER_SLICE_SIZE (buffer);
539 /* free our memory */
540 len = GST_BUFFER_MEM_LEN (buffer);
541 for (i = 0; i < len; i++) {
542 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
543 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
546 /* we set msize to 0 when the buffer is part of the memory block */
549 memset (buffer, 0xff, msize);
551 g_slice_free1 (msize, buffer);
553 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
558 gst_buffer_init (GstBufferImpl * buffer, gsize size)
560 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
561 (GstMiniObjectCopyFunction) _gst_buffer_copy,
562 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
563 (GstMiniObjectFreeFunction) _gst_buffer_free);
565 GST_BUFFER_SLICE_SIZE (buffer) = size;
567 GST_BUFFER (buffer)->pool = NULL;
568 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
569 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
570 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
571 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
572 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
574 GST_BUFFER_MEM_LEN (buffer) = 0;
575 GST_BUFFER_META (buffer) = NULL;
581 * Creates a newly allocated buffer without any data.
585 * Returns: (transfer full): the new #GstBuffer.
588 gst_buffer_new (void)
590 GstBufferImpl *newbuf;
592 newbuf = g_slice_new (GstBufferImpl);
593 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
595 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
597 return GST_BUFFER_CAST (newbuf);
601 * gst_buffer_new_allocate:
602 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or NULL to use the
604 * @size: the size in bytes of the new buffer's data.
605 * @params: (transfer none) (allow-none): optional parameters
607 * Tries to create a newly allocated buffer with data of the given size and
608 * extra parameters from @allocator. If the requested amount of memory can't be
609 * allocated, NULL will be returned. The allocated buffer memory is not cleared.
611 * When @allocator is NULL, the default memory allocator will be used.
613 * Note that when @size == 0, the buffer will not have memory associated with it.
617 * Returns: (transfer full): a new #GstBuffer, or NULL if the memory couldn't
621 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
622 GstAllocationParams * params)
633 mem = gst_allocator_alloc (allocator, size, params);
634 if (G_UNLIKELY (mem == NULL))
640 newbuf = gst_buffer_new ();
643 _memory_add (newbuf, -1, mem, TRUE);
645 GST_CAT_LOG (GST_CAT_BUFFER,
646 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
651 asize = sizeof (GstBufferImpl) + size;
652 data = g_slice_alloc (asize);
653 if (G_UNLIKELY (data == NULL))
656 newbuf = GST_BUFFER_CAST (data);
658 gst_buffer_init ((GstBufferImpl *) data, asize);
660 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
662 _memory_add (newbuf, -1, mem, TRUE);
667 /* allocate memory and buffer, it might be interesting to do this but there
668 * are many complications. We need to keep the memory mapped to access the
669 * buffer fields and the memory for the buffer might be just very slow. We
670 * also need to do some more magic to get the alignment right. */
671 asize = sizeof (GstBufferImpl) + size;
672 mem = gst_allocator_alloc (allocator, asize, align);
673 if (G_UNLIKELY (mem == NULL))
676 /* map the data part and init the buffer in it, set the buffer size to 0 so
677 * that a finalize won't free the buffer */
678 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
679 gst_buffer_init ((GstBufferImpl *) data, 0);
680 gst_memory_unmap (mem);
682 /* strip off the buffer */
683 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
685 newbuf = GST_BUFFER_CAST (data);
686 GST_BUFFER_BUFMEM (newbuf) = mem;
689 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
697 GST_CAT_WARNING (GST_CAT_BUFFER,
698 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
704 * gst_buffer_new_wrapped_full:
705 * @flags: #GstMemoryFlags
706 * @data: (array length=size) (element-type guint8): data to wrap
707 * @maxsize: allocated size of @data
708 * @offset: offset in @data
709 * @size: size of valid data
710 * @user_data: user_data
711 * @notify: called with @user_data when the memory is freed
713 * Allocate a new buffer that wraps the given memory. @data must point to
714 * @maxsize of memory, the wrapped buffer will have the region from @offset and
717 * When the buffer is destroyed, @notify will be called with @user_data.
719 * The prefix/padding must be filled with 0 if @flags contains
720 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
722 * Returns: (transfer full): a new #GstBuffer
725 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
726 gsize maxsize, gsize offset, gsize size, gpointer user_data,
727 GDestroyNotify notify)
731 newbuf = gst_buffer_new ();
732 gst_buffer_append_memory (newbuf,
733 gst_memory_new_wrapped (flags, data, maxsize, offset, size,
740 * gst_buffer_new_wrapped:
741 * @data: (array length=size) (element-type guint8): data to wrap
742 * @size: allocated size of @data
744 * Creates a new buffer that wraps the given @data. The memory will be freed
745 * with g_free and will be marked writable.
749 * Returns: (transfer full): a new #GstBuffer
752 gst_buffer_new_wrapped (gpointer data, gsize size)
754 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
758 * gst_buffer_n_memory:
759 * @buffer: a #GstBuffer.
761 * Get the amount of memory blocks that this buffer has.
763 * Returns: (transfer full): the amount of memory block in this buffer.
766 gst_buffer_n_memory (GstBuffer * buffer)
768 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
770 return GST_BUFFER_MEM_LEN (buffer);
774 * gst_buffer_prepend_memory:
775 * @buffer: a #GstBuffer.
776 * @mem: (transfer full): a #GstMemory.
778 * Prepend the memory block @mem to @buffer. This function takes
779 * ownership of @mem and thus doesn't increase its refcount.
782 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
784 gst_buffer_insert_memory (buffer, 0, mem);
788 * gst_buffer_append_memory:
789 * @buffer: a #GstBuffer.
790 * @mem: (transfer full): a #GstMemory.
792 * Append the memory block @mem to @buffer. This function takes
793 * ownership of @mem and thus doesn't increase its refcount.
796 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
798 gst_buffer_insert_memory (buffer, -1, mem);
802 * gst_buffer_insert_memory:
803 * @buffer: a #GstBuffer.
804 * @idx: the index to add the memory at, or -1 to append it to the end
805 * @mem: (transfer full): a #GstMemory.
807 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
808 * of @mem and thus doesn't increase its refcount.
811 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
813 g_return_if_fail (GST_IS_BUFFER (buffer));
814 g_return_if_fail (gst_buffer_is_writable (buffer));
815 g_return_if_fail (mem != NULL);
816 g_return_if_fail (idx == -1 ||
817 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
819 _memory_add (buffer, idx, mem, TRUE);
823 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
826 GstMemory *mem, *mapped;
828 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
830 mapped = gst_memory_make_mapped (mem, info, flags);
833 /* memory changed, lock new memory */
834 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
835 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
836 /* unlock old memory */
837 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
839 gst_memory_unref (mem);
845 * gst_buffer_peek_memory:
846 * @buffer: a #GstBuffer.
849 * Get the memory block at @idx in @buffer. The memory block stays valid until
850 * the memory block in @buffer is removed, replaced or merged, typically with
851 * any call that modifies the memory in @buffer.
853 * Since this call does not influence the refcount of the memory,
854 * gst_memory_is_writable() can be used to check if @buffer is the sole owner
855 * of the returned memory.
857 * Returns: (transfer none): the #GstMemory at @idx.
860 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
864 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
865 len = GST_BUFFER_MEM_LEN (buffer);
866 g_return_val_if_fail (idx < len, NULL);
868 return GST_BUFFER_MEM_PTR (buffer, idx);
872 * gst_buffer_get_memory:
873 * @buffer: a #GstBuffer.
876 * Get the memory block at index @idx in @buffer.
878 * Returns: (transfer full): a #GstMemory that contains the data of the
879 * memory block at @idx. Use gst_memory_unref () after usage.
882 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
884 return gst_buffer_get_memory_range (buffer, idx, 1);
888 * gst_buffer_get_all_memory:
889 * @buffer: a #GstBuffer.
891 * Get all the memory block in @buffer. The memory blocks will be merged
892 * into one large #GstMemory.
894 * Returns: (transfer full): a #GstMemory that contains the merged memory.
895 * Use gst_memory_unref () after usage.
898 gst_buffer_get_all_memory (GstBuffer * buffer)
900 return gst_buffer_get_memory_range (buffer, 0, -1);
904 * gst_buffer_get_memory_range:
905 * @buffer: a #GstBuffer.
909 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
910 * be merged into one large #GstMemory.
912 * If @length is -1, all memory starting from @idx is merged.
914 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
915 * blocks starting at @idx. Use gst_memory_unref () after usage.
918 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
922 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
924 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
925 len = GST_BUFFER_MEM_LEN (buffer);
926 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
927 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
932 return _get_merged_memory (buffer, idx, length);
936 * gst_buffer_replace_memory:
937 * @buffer: a #GstBuffer.
939 * @mem: (transfer full): a #GstMemory
941 * Replaces the memory block at index @idx in @buffer with @mem.
944 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
946 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
950 * gst_buffer_replace_all_memory:
951 * @buffer: a #GstBuffer.
952 * @mem: (transfer full): a #GstMemory
954 * Replaces all memory in @buffer with @mem.
957 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
959 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
963 * gst_buffer_replace_memory_range:
964 * @buffer: a #GstBuffer.
966 * @length: a length should not be 0
967 * @mem: (transfer full): a #GstMemory
969 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
971 * If @length is -1, all memory starting from @idx will be removed and
972 * replaced with @mem.
974 * @buffer should be writable.
977 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
982 g_return_if_fail (GST_IS_BUFFER (buffer));
983 g_return_if_fail (gst_buffer_is_writable (buffer));
985 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
987 len = GST_BUFFER_MEM_LEN (buffer);
988 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
989 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
994 _replace_memory (buffer, len, idx, length, mem);
998 * gst_buffer_remove_memory:
999 * @buffer: a #GstBuffer.
1002 * Remove the memory block in @b at index @i.
1005 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1007 gst_buffer_remove_memory_range (buffer, idx, 1);
1011 * gst_buffer_remove_all_memory:
1012 * @buffer: a #GstBuffer.
1014 * Remove all the memory blocks in @buffer.
1017 gst_buffer_remove_all_memory (GstBuffer * buffer)
1019 gst_buffer_remove_memory_range (buffer, 0, -1);
1023 * gst_buffer_remove_memory_range:
1024 * @buffer: a #GstBuffer.
1028 * Remove @length memory blocks in @buffer starting from @idx.
1030 * @length can be -1, in which case all memory starting from @idx is removed.
1033 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1037 g_return_if_fail (GST_IS_BUFFER (buffer));
1038 g_return_if_fail (gst_buffer_is_writable (buffer));
1040 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1042 len = GST_BUFFER_MEM_LEN (buffer);
1043 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1044 (length == -1 && idx < len) || length + idx <= len);
1049 _replace_memory (buffer, len, idx, length, NULL);
1053 * gst_buffer_find_memory:
1054 * @buffer: a #GstBuffer.
1055 * @offset: an offset
1057 * @idx: (out): pointer to index
1058 * @length: (out): pointer to length
1059 * @skip: (out): pointer to skip
1061 * Find the memory blocks that span @size bytes starting from @offset
1064 * When this function returns %TRUE, @idx will contain the index of the first
1065 * memory bock where the byte for @offset can be found and @length contains the
1066 * number of memory blocks containing the @size remaining bytes. @skip contains
1067 * the number of bytes to skip in the memory bock at @idx to get to the byte
1070 * @size can be -1 to get all the memory blocks after @idx.
1072 * Returns: %TRUE when @size bytes starting from @offset could be found in
1073 * @buffer and @idx, @length and @skip will be filled.
1076 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1077 guint * idx, guint * length, gsize * skip)
1079 guint i, len, found;
1081 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1082 g_return_val_if_fail (idx != NULL, FALSE);
1083 g_return_val_if_fail (length != NULL, FALSE);
1084 g_return_val_if_fail (skip != NULL, FALSE);
1086 len = GST_BUFFER_MEM_LEN (buffer);
1089 for (i = 0; i < len; i++) {
1093 mem = GST_BUFFER_MEM_PTR (buffer, i);
1094 s = gst_memory_get_sizes (mem, NULL, NULL);
1097 /* block before offset, or empty block, skip */
1100 /* block after offset */
1102 /* first block, remember index and offset */
1106 /* return remaining blocks */
1113 /* count the amount of found bytes */
1115 if (found >= size) {
1116 /* we have enough bytes */
1117 *length = i - *idx + 1;
1126 * gst_buffer_get_sizes:
1127 * @buffer: a #GstBuffer.
1128 * @offset: (out): a pointer to the offset
1129 * @maxsize: (out): a pointer to the maxsize
1131 * Get the total size of the memory blocks in @b.
1133 * When not %NULL, @offset will contain the offset of the data in the
1134 * first memory block in @buffer and @maxsize will contain the sum of
1135 * the size and @offset and the amount of extra padding on the last
1136 * memory block. @offset and @maxsize can be used to resize the
1137 * buffer memory blocks with gst_buffer_resize().
1139 * Returns: total size of the memory blocks in @buffer.
1142 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1144 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1148 * gst_buffer_get_size:
1149 * @buffer: a #GstBuffer.
1151 * Get the total size of the memory blocks in @buffer.
1153 * Returns: total size of the memory blocks in @buffer.
1156 gst_buffer_get_size (GstBuffer * buffer)
1158 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1162 * gst_buffer_get_sizes_range:
1163 * @buffer: a #GstBuffer.
1166 * @offset: (out): a pointer to the offset
1167 * @maxsize: (out): a pointer to the maxsize
1169 * Get the total size of @length memory blocks stating from @idx in @buffer.
1171 * When not %NULL, @offset will contain the offset of the data in the
1172 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1173 * and @offset and the amount of extra padding on the memory block at @idx +
1175 * @offset and @maxsize can be used to resize the buffer memory blocks with
1176 * gst_buffer_resize_range().
1178 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1181 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1182 gsize * offset, gsize * maxsize)
1188 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1189 len = GST_BUFFER_MEM_LEN (buffer);
1190 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1191 (length == -1 && idx < len) || (length + idx <= len), 0);
1196 if (G_LIKELY (length == 1)) {
1198 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1199 size = gst_memory_get_sizes (mem, offset, maxsize);
1205 size = offs = extra = 0;
1206 for (i = idx; i < end; i++) {
1209 mem = GST_BUFFER_MEM_PTR (buffer, i);
1210 s = gst_memory_get_sizes (mem, &o, &ms);
1214 /* first size, take accumulated data before as the offset */
1218 /* save the amount of data after this block */
1219 extra = ms - (o + s);
1221 /* empty block, add as extra */
1228 *maxsize = offs + size + extra;
1234 * gst_buffer_resize:
1235 * @buffer: a #GstBuffer.
1236 * @offset: the offset adjustement
1237 * @size: the new size or -1 to just adjust the offset
1239 * Set the offset and total size of the memory blocks in @buffer.
1242 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1244 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1248 * gst_buffer_set_size:
1249 * @buffer: a #GstBuffer.
1250 * @size: the new size
1252 * Set the total size of the memory blocks in @buffer.
1255 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1257 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1261 * gst_buffer_resize_range:
1262 * @buffer: a #GstBuffer.
1265 * @offset: the offset adjustement
1266 * @size: the new size or -1 to just adjust the offset
1268 * Set the total size of the @length memory blocks starting at @idx in
1272 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1273 gssize offset, gssize size)
1276 gsize bsize, bufsize, bufoffs, bufmax;
1278 g_return_if_fail (gst_buffer_is_writable (buffer));
1279 g_return_if_fail (size >= -1);
1280 len = GST_BUFFER_MEM_LEN (buffer);
1281 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1282 (length == -1 && idx < len) || (length + idx <= len));
1287 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1289 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1290 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1291 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1293 /* we can't go back further than the current offset or past the end of the
1295 g_return_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1296 && bufoffs + offset <= bufmax));
1298 g_return_if_fail (bufsize >= offset);
1299 size = bufsize - offset;
1301 g_return_if_fail (bufmax >= bufoffs + offset + size);
1304 if (offset == 0 && size == bufsize)
1309 for (i = idx; i < end; i++) {
1313 mem = GST_BUFFER_MEM_PTR (buffer, i);
1314 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1317 /* last buffer always gets resized to the remaining size */
1320 /* shrink buffers before the offset */
1321 else if ((gssize) bsize <= offset) {
1323 noffs = offset - bsize;
1326 /* clip other buffers */
1328 left = MIN (bsize - offset, size);
1330 if (offset != 0 || left != bsize) {
1331 if (gst_memory_is_writable (mem)) {
1332 gst_memory_resize (mem, offset, left);
1334 GstMemory *newmem = NULL;
1336 if (!GST_MEMORY_IS_NO_SHARE (mem))
1337 newmem = gst_memory_share (mem, offset, left);
1340 newmem = gst_memory_copy (mem, offset, left);
1342 g_return_if_fail (newmem != NULL);
1344 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1345 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1346 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1347 gst_memory_unref (mem);
1358 * @buffer: a #GstBuffer.
1359 * @info: (out): info about the mapping
1360 * @flags: flags for the mapping
1362 * This function fills @info with the #GstMapInfo of all merged memory
1363 * blocks in @buffer.
1365 * @flags describe the desired access of the memory. When @flags is
1366 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1367 * gst_buffer_is_writable()).
1369 * When @buffer is writable but the memory isn't, a writable copy will
1370 * automatically be created and returned. The readonly copy of the
1371 * buffer memory will then also be replaced with this writable copy.
1373 * The memory in @info should be unmapped with gst_buffer_unmap() after
1376 * Returns: %TRUE if the map succeeded and @info contains valid data.
1379 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1381 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1385 * gst_buffer_map_range:
1386 * @buffer: a #GstBuffer.
1389 * @info: (out): info about the mapping
1390 * @flags: flags for the mapping
1392 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1393 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1394 * from @idx are merged and mapped.
1396 * @flags describe the desired access of the memory. When @flags is
1397 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1398 * gst_buffer_is_writable()).
1400 * When @buffer is writable but the memory isn't, a writable copy will
1401 * automatically be created and returned. The readonly copy of the buffer memory
1402 * will then also be replaced with this writable copy.
1404 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1406 * Returns: %TRUE if the map succeeded and @info contains valid
1410 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1411 GstMapInfo * info, GstMapFlags flags)
1413 GstMemory *mem, *nmem;
1414 gboolean write, writable;
1417 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1418 g_return_val_if_fail (info != NULL, FALSE);
1419 len = GST_BUFFER_MEM_LEN (buffer);
1420 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1421 (length == -1 && idx < len) || (length > 0
1422 && length + idx <= len), FALSE);
1424 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1425 buffer, idx, length, flags);
1427 write = (flags & GST_MAP_WRITE) != 0;
1428 writable = gst_buffer_is_writable (buffer);
1430 /* check if we can write when asked for write access */
1431 if (G_UNLIKELY (write && !writable))
1437 mem = _get_merged_memory (buffer, idx, length);
1438 if (G_UNLIKELY (mem == NULL))
1441 /* now try to map */
1442 nmem = gst_memory_make_mapped (mem, info, flags);
1443 if (G_UNLIKELY (nmem == NULL))
1446 /* if we merged or when the map returned a different memory, we try to replace
1447 * the memory in the buffer */
1448 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1449 /* if the buffer is writable, replace the memory */
1451 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1454 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1455 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1464 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1465 g_critical ("write map requested on non-writable buffer");
1470 /* empty buffer, we need to return NULL */
1471 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1472 info->memory = NULL;
1480 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1487 * @buffer: a #GstBuffer.
1488 * @info: a #GstMapInfo
1490 * Release the memory previously mapped with gst_buffer_map().
1493 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1495 g_return_if_fail (GST_IS_BUFFER (buffer));
1496 g_return_if_fail (info != NULL);
1498 /* we need to check for NULL, it is possible that we tried to map a buffer
1499 * without memory and we should be able to unmap that fine */
1500 if (G_LIKELY (info->memory)) {
1501 gst_memory_unmap (info->memory, info);
1502 gst_memory_unref (info->memory);
1508 * @buffer: a #GstBuffer.
1509 * @offset: the offset to fill
1510 * @src: the source address
1511 * @size: the size to fill
1513 * Copy @size bytes from @src to @buffer at @offset.
1515 * Returns: The amount of bytes copied. This value can be lower than @size
1516 * when @buffer did not contain enough data.
1519 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1523 const guint8 *ptr = src;
1525 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1526 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1527 g_return_val_if_fail (src != NULL, 0);
1529 GST_CAT_LOG (GST_CAT_BUFFER,
1530 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1533 len = GST_BUFFER_MEM_LEN (buffer);
1536 for (i = 0; i < len && left > 0; i++) {
1541 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1542 if (info.size > offset) {
1543 /* we have enough */
1544 tocopy = MIN (info.size - offset, left);
1545 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1550 /* offset past buffer, skip */
1551 offset -= info.size;
1553 gst_memory_unmap (mem, &info);
1559 * gst_buffer_extract:
1560 * @buffer: a #GstBuffer.
1561 * @offset: the offset to extract
1562 * @dest: the destination address
1563 * @size: the size to extract
1565 * Copy @size bytes starting from @offset in @buffer to @dest.
1567 * Returns: The amount of bytes extracted. This value can be lower than @size
1568 * when @buffer did not contain enough data.
1571 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1576 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1577 g_return_val_if_fail (dest != NULL, 0);
1579 GST_CAT_LOG (GST_CAT_BUFFER,
1580 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1583 len = GST_BUFFER_MEM_LEN (buffer);
1586 for (i = 0; i < len && left > 0; i++) {
1591 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1592 if (info.size > offset) {
1593 /* we have enough */
1594 tocopy = MIN (info.size - offset, left);
1595 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1600 /* offset past buffer, skip */
1601 offset -= info.size;
1603 gst_memory_unmap (mem, &info);
1609 * gst_buffer_memcmp:
1610 * @buffer: a #GstBuffer.
1611 * @offset: the offset in @buffer
1612 * @mem: the memory to compare
1613 * @size: the size to compare
1615 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1617 * Returns: 0 if the memory is equal.
1620 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1624 const guint8 *ptr = mem;
1627 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1628 g_return_val_if_fail (mem != NULL, 0);
1630 GST_CAT_LOG (GST_CAT_BUFFER,
1631 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1634 len = GST_BUFFER_MEM_LEN (buffer);
1636 for (i = 0; i < len && size > 0 && res == 0; i++) {
1641 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1642 if (info.size > offset) {
1643 /* we have enough */
1644 tocmp = MIN (info.size - offset, size);
1645 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1650 /* offset past buffer, skip */
1651 offset -= info.size;
1653 gst_memory_unmap (mem, &info);
1659 * gst_buffer_memset:
1660 * @buffer: a #GstBuffer.
1661 * @offset: the offset in @buffer
1662 * @val: the value to set
1663 * @size: the size to set
1665 * Fill @buf with @size bytes with @val starting from @offset.
1667 * Returns: The amount of bytes filled. This value can be lower than @size
1668 * when @buffer did not contain enough data.
1671 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1675 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1676 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1678 GST_CAT_LOG (GST_CAT_BUFFER,
1679 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1680 buffer, offset, val, size);
1682 len = GST_BUFFER_MEM_LEN (buffer);
1685 for (i = 0; i < len && left > 0; i++) {
1690 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1691 if (info.size > offset) {
1692 /* we have enough */
1693 toset = MIN (info.size - offset, left);
1694 memset ((guint8 *) info.data + offset, val, toset);
1698 /* offset past buffer, skip */
1699 offset -= info.size;
1701 gst_memory_unmap (mem, &info);
1707 * gst_buffer_copy_region:
1708 * @parent: a #GstBuffer.
1709 * @flags: the #GstBufferCopyFlags
1710 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1712 * @size: the size of the new #GstBuffer sub-buffer, in bytes.
1714 * Creates a sub-buffer from @parent at @offset and @size.
1715 * This sub-buffer uses the actual memory space of the parent buffer.
1716 * This function will copy the offset and timestamp fields when the
1717 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1718 * #GST_BUFFER_OFFSET_NONE.
1719 * If @offset equals 0 and @size equals the total size of @buffer, the
1720 * duration and offset end fields are also copied. If not they will be set
1721 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1725 * Returns: (transfer full): the new #GstBuffer or NULL if the arguments were
1729 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1730 gsize offset, gsize size)
1734 g_return_val_if_fail (buffer != NULL, NULL);
1736 /* create the new buffer */
1737 copy = gst_buffer_new ();
1739 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1740 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1742 gst_buffer_copy_into (copy, buffer, flags, offset, size);
1748 * gst_buffer_append:
1749 * @buf1: (transfer full): the first source #GstBuffer to append.
1750 * @buf2: (transfer full): the second source #GstBuffer to append.
1752 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1753 * concatenation of the memory of @buf1 and @buf2.
1755 * Returns: (transfer full): the new #GstBuffer that contains the memory
1756 * of the two source buffers.
1759 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1761 return gst_buffer_append_region (buf1, buf2, 0, -1);
1765 * gst_buffer_append_region:
1766 * @buf1: (transfer full): the first source #GstBuffer to append.
1767 * @buf2: (transfer full): the second source #GstBuffer to append.
1768 * @offset: the offset in @buf2
1769 * @size: the size or -1 of @buf2
1771 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1772 * contain a concatenation of the memory of @buf1 and the requested region of
1775 * Returns: (transfer full): the new #GstBuffer that contains the memory
1776 * of the two source buffers.
1779 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
1784 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1785 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1787 buf1 = gst_buffer_make_writable (buf1);
1788 buf2 = gst_buffer_make_writable (buf2);
1790 gst_buffer_resize (buf2, offset, size);
1792 len = GST_BUFFER_MEM_LEN (buf2);
1793 for (i = 0; i < len; i++) {
1796 mem = GST_BUFFER_MEM_PTR (buf2, i);
1797 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1798 _memory_add (buf1, -1, mem, FALSE);
1801 GST_BUFFER_MEM_LEN (buf2) = 0;
1802 gst_buffer_unref (buf2);
1808 * gst_buffer_get_meta:
1809 * @buffer: a #GstBuffer
1810 * @api: the #GType of an API
1812 * Get the metadata for @api on buffer. When there is no such
1813 * metadata, NULL is returned.
1815 * Returns: (transfer none): the metadata for @api on @buffer.
1818 gst_buffer_get_meta (GstBuffer * buffer, GType api)
1821 GstMeta *result = NULL;
1823 g_return_val_if_fail (buffer != NULL, NULL);
1824 g_return_val_if_fail (api != 0, NULL);
1826 /* find GstMeta of the requested API */
1827 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
1828 GstMeta *meta = &item->meta;
1829 if (meta->info->api == api) {
1838 * gst_buffer_add_meta:
1839 * @buffer: a #GstBuffer
1840 * @info: a #GstMetaInfo
1841 * @params: params for @info
1843 * Add metadata for @info to @buffer using the parameters in @params.
1845 * Returns: (transfer none): the metadata for the api in @info on @buffer.
1848 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
1852 GstMeta *result = NULL;
1855 g_return_val_if_fail (buffer != NULL, NULL);
1856 g_return_val_if_fail (info != NULL, NULL);
1857 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
1859 /* create a new slice */
1860 size = ITEM_SIZE (info);
1861 item = g_slice_alloc (size);
1862 result = &item->meta;
1863 result->info = info;
1864 result->flags = GST_META_FLAG_NONE;
1866 GST_CAT_DEBUG (GST_CAT_BUFFER,
1867 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
1868 g_type_name (info->type), info->size);
1870 /* call the init_func when needed */
1871 if (info->init_func)
1872 if (!info->init_func (result, params, buffer))
1875 /* and add to the list of metadata */
1876 item->next = GST_BUFFER_META (buffer);
1877 GST_BUFFER_META (buffer) = item;
1883 g_slice_free1 (size, item);
1889 * gst_buffer_remove_meta:
1890 * @buffer: a #GstBuffer
1893 * Remove the metadata for @meta on @buffer.
1895 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
1896 * metadata was on @buffer.
1899 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
1901 GstMetaItem *walk, *prev;
1903 g_return_val_if_fail (buffer != NULL, FALSE);
1904 g_return_val_if_fail (meta != NULL, FALSE);
1905 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1906 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
1909 /* find the metadata and delete */
1910 prev = GST_BUFFER_META (buffer);
1911 for (walk = prev; walk; walk = walk->next) {
1912 GstMeta *m = &walk->meta;
1914 const GstMetaInfo *info = meta->info;
1916 /* remove from list */
1917 if (GST_BUFFER_META (buffer) == walk)
1918 GST_BUFFER_META (buffer) = walk->next;
1920 prev->next = walk->next;
1921 /* call free_func if any */
1922 if (info->free_func)
1923 info->free_func (m, buffer);
1925 /* and free the slice */
1926 g_slice_free1 (ITEM_SIZE (info), walk);
1931 return walk != NULL;
1935 * gst_buffer_iterate_meta:
1936 * @buffer: a #GstBuffer
1937 * @state: an opaque state pointer
1939 * Retrieve the next #GstMeta after @current. If @state points
1940 * to %NULL, the first metadata is returned.
1942 * @state will be updated with an opage state pointer
1944 * Returns: (transfer none): The next #GstMeta or %NULL when there are
1948 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
1952 g_return_val_if_fail (buffer != NULL, NULL);
1953 g_return_val_if_fail (state != NULL, NULL);
1955 meta = (GstMetaItem **) state;
1957 /* state NULL, move to first item */
1958 *meta = GST_BUFFER_META (buffer);
1960 /* state !NULL, move to next item in list */
1961 *meta = (*meta)->next;
1964 return &(*meta)->meta;
1970 * gst_buffer_foreach_meta:
1971 * @buffer: a #GstBuffer
1972 * @func: (scope call): a #GstBufferForeachMetaFunc to call
1973 * @user_data: (closure): user data passed to @func
1975 * Call @func with @user_data for each meta in @buffer.
1977 * @func can modify the passed meta pointer or its contents. The return value
1978 * of @func define if this function returns or if the remaining metadata items
1979 * in the buffer should be skipped.
1981 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
1984 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
1987 GstMetaItem *walk, *prev, *next;
1988 gboolean res = TRUE;
1990 g_return_val_if_fail (buffer != NULL, FALSE);
1991 g_return_val_if_fail (func != NULL, FALSE);
1993 /* find the metadata and delete */
1994 prev = GST_BUFFER_META (buffer);
1995 for (walk = prev; walk; walk = next) {
1998 m = new = &walk->meta;
2001 res = func (buffer, &new, user_data);
2004 const GstMetaInfo *info = m->info;
2006 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2007 g_type_name (info->type));
2009 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2010 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2013 /* remove from list */
2014 if (GST_BUFFER_META (buffer) == walk)
2015 GST_BUFFER_META (buffer) = next;
2019 /* call free_func if any */
2020 if (info->free_func)
2021 info->free_func (m, buffer);
2023 /* and free the slice */
2024 g_slice_free1 (ITEM_SIZE (info), walk);