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.
39 * gint size, width, height, bpp;
41 * size = width * height * bpp;
42 * buffer = gst_buffer_new ();
43 * memory = gst_allocator_alloc (NULL, size, NULL);
44 * gst_buffer_insert_memory (buffer, -1, memory);
48 * Alternatively, use gst_buffer_new_allocate() to create a buffer with
49 * preallocated data of a given size.
51 * Buffers can contain a list of #GstMemory objects. You can retrieve how many
52 * memory objects with gst_buffer_n_memory() and you can get a pointer
53 * to memory with gst_buffer_peek_memory()
55 * A buffer will usually have timestamps, and a duration, but neither of these
56 * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
57 * meaningful value can be given for these, they should be set. The timestamps
58 * and duration are measured in nanoseconds (they are #GstClockTime values).
60 * The buffer DTS refers to the timestamp when the buffer should be decoded and
61 * is usually monotonically increasing. The buffer PTS refers to the timestamp when
62 * the buffer content should be presented to the user and is not always
63 * monotonically increasing.
65 * A buffer can also have one or both of a start and an end offset. These are
66 * media-type specific. For video buffers, the start offset will generally be
67 * the frame number. For audio buffers, it will be the number of samples
68 * produced so far. For compressed data, it could be the byte offset in a
69 * source or destination file. Likewise, the end offset will be the offset of
70 * the end of the buffer. These can only be meaningfully interpreted if you
71 * know the media type of the buffer (the preceding CAPS event). Either or both
72 * can be set to #GST_BUFFER_OFFSET_NONE.
74 * gst_buffer_ref() is used to increase the refcount of a buffer. This must be
75 * done when you want to keep a handle to the buffer after pushing it to the
76 * next element. The buffer refcount determines the writability of the buffer, a
77 * buffer is only writable when the refcount is exactly 1, i.e. when the caller
78 * has the only reference to the buffer.
80 * To efficiently create a smaller buffer out of an existing one, you can
81 * use gst_buffer_copy_region(). This method tries to share the memory objects
82 * between the two buffers.
84 * If a plug-in wants to modify the buffer data or metadata in-place, it should
85 * first obtain a buffer that is safe to modify by using
86 * gst_buffer_make_writable(). This function is optimized so that a copy will
87 * only be made when it is necessary.
89 * Several flags of the buffer can be set and unset with the
90 * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
91 * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlags flag is set.
93 * Buffers can be efficiently merged into a larger buffer with
94 * gst_buffer_append(). Copying of memory will only be done when absolutely
97 * Arbitrary extra metadata can be set on a buffer with gst_buffer_add_meta().
98 * Metadata can be retrieved with gst_buffer_get_meta(). See also #GstMeta
100 * An element should either unref the buffer or push it out on a src pad
101 * using gst_pad_push() (see #GstPad).
103 * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
104 * the refcount drops to 0, any memory and metadata pointed to by the buffer is
105 * unreffed as well. Buffers allocated from a #GstBufferPool will be returned to
106 * the pool when the refcount drops to 0.
108 * The #GstParentBufferMeta is a meta which can be attached to a #GstBuffer
109 * to hold a reference to another buffer that is only released when the child
110 * #GstBuffer is released.
112 * Typically, #GstParentBufferMeta is used when the child buffer is directly
113 * using the #GstMemory of the parent buffer, and wants to prevent the parent
114 * buffer from being returned to a buffer pool until the #GstMemory is available
115 * for re-use. (Since: 1.6)
118 #include "gst_private.h"
127 #include "gstbuffer.h"
128 #include "gstbufferpool.h"
130 #include "gstutils.h"
131 #include "gstversion.h"
133 GType _gst_buffer_type = 0;
135 typedef struct _GstMetaItem GstMetaItem;
142 #define ITEM_SIZE(info) ((info)->size + sizeof (GstMetaItem))
144 #define GST_BUFFER_MEM_MAX 16
146 #define GST_BUFFER_SLICE_SIZE(b) (((GstBufferImpl *)(b))->slice_size)
147 #define GST_BUFFER_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
148 #define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
149 #define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
150 #define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
151 #define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
159 /* the memory blocks */
161 GstMemory *mem[GST_BUFFER_MEM_MAX];
163 /* memory of the buffer when allocated from 1 chunk */
166 /* FIXME, make metadata allocation more efficient by using part of the
173 _is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
175 GstMemory *mcur, *mprv;
176 gboolean have_offset = FALSE;
181 for (i = 0; i < len; i++) {
189 /* check if memory is contiguous */
190 if (!gst_memory_is_span (mprv, mcur, &poffs))
197 *parent = mprv->parent;
207 _get_merged_memory (GstBuffer * buffer, guint idx, guint length)
209 GstMemory **mem, *result = NULL;
211 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %u", buffer, idx,
214 mem = GST_BUFFER_MEM_ARRAY (buffer);
216 if (G_UNLIKELY (length == 0)) {
218 } else if (G_LIKELY (length == 1)) {
219 result = gst_memory_ref (mem[idx]);
221 GstMemory *parent = NULL;
222 gsize size, poffset = 0;
224 size = gst_buffer_get_sizes_range (buffer, idx, length, NULL, NULL);
226 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
227 if (!GST_MEMORY_IS_NO_SHARE (parent))
228 result = gst_memory_share (parent, poffset, size);
230 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
231 result = gst_memory_copy (parent, poffset, size);
234 gsize i, tocopy, left;
235 GstMapInfo sinfo, dinfo;
238 result = gst_allocator_alloc (NULL, size, NULL);
239 gst_memory_map (result, &dinfo, GST_MAP_WRITE);
244 for (i = idx; i < (idx + length) && left > 0; i++) {
245 gst_memory_map (mem[i], &sinfo, GST_MAP_READ);
246 tocopy = MIN (sinfo.size, left);
247 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
248 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
249 tocopy, result, mem[i]);
250 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
253 gst_memory_unmap (mem[i], &sinfo);
255 gst_memory_unmap (result, &dinfo);
262 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
269 GST_CAT_LOG (GST_CAT_BUFFER,
270 "buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
273 /* unref old memory */
274 for (i = idx; i < end; i++) {
275 GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
277 gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
278 gst_memory_unref (old);
282 /* replace with single memory */
283 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
284 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
290 memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
291 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
293 GST_BUFFER_MEM_LEN (buffer) = len - length;
294 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
297 /* transfer full for return and transfer none for @mem */
298 static inline GstMemory *
299 _memory_get_exclusive_reference (GstMemory * mem)
301 GstMemory *ret = NULL;
303 if (gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE)) {
304 ret = gst_memory_ref (mem);
306 /* we cannot take another exclusive lock as the memory is already
307 * locked WRITE + EXCLUSIVE according to part-miniobject.txt */
308 ret = gst_memory_copy (mem, 0, -1);
311 if (!gst_memory_lock (ret, GST_LOCK_FLAG_EXCLUSIVE)) {
312 gst_memory_unref (ret);
319 GST_CAT_WARNING (GST_CAT_BUFFER, "Failed to acquire an exclusive lock for "
326 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem)
328 guint i, len = GST_BUFFER_MEM_LEN (buffer);
330 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p", buffer, idx, mem);
332 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
333 /* too many buffer, span them. */
334 /* FIXME, there is room for improvement here: We could only try to merge
335 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
336 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
337 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
339 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
340 /* we now have 1 single spanned buffer */
347 for (i = len; i > idx; i--) {
348 /* move buffers to insert, FIXME, we need to insert first and then merge */
349 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
351 /* and insert the new buffer */
352 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
353 GST_BUFFER_MEM_LEN (buffer) = len + 1;
355 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
358 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
361 _priv_gst_buffer_initialize (void)
363 _gst_buffer_type = gst_buffer_get_type ();
367 * gst_buffer_get_max_memory:
369 * Get the maximum amount of memory blocks that a buffer can hold. This is a
370 * compile time constant that can be queried with the function.
372 * When more memory blocks are added, existing memory blocks will be merged
373 * together to make room for the new block.
375 * Returns: the maximum amount of memory blocks that a buffer can hold.
380 gst_buffer_get_max_memory (void)
382 return GST_BUFFER_MEM_MAX;
386 * gst_buffer_copy_into:
387 * @dest: a destination #GstBuffer
388 * @src: a source #GstBuffer
389 * @flags: flags indicating what metadata fields should be copied.
390 * @offset: offset to copy from
391 * @size: total size to copy. If -1, all data is copied.
393 * Copies the information from @src into @dest.
395 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
396 * the memory from @src will be appended to @dest.
398 * @flags indicate which fields will be copied.
400 * Returns: %TRUE if the copying succeeded, %FALSE otherwise.
403 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
404 GstBufferCopyFlags flags, gsize offset, gsize size)
408 gboolean region = FALSE;
410 g_return_val_if_fail (dest != NULL, FALSE);
411 g_return_val_if_fail (src != NULL, FALSE);
413 /* nothing to copy if the buffers are the same */
414 if (G_UNLIKELY (dest == src))
417 g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
419 bufsize = gst_buffer_get_size (src);
420 g_return_val_if_fail (bufsize >= offset, FALSE);
424 size = bufsize - offset;
427 g_return_val_if_fail (bufsize >= offset + size, FALSE);
429 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
430 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
433 if (flags & GST_BUFFER_COPY_FLAGS) {
435 guint flags_mask = ~GST_BUFFER_FLAG_TAG_MEMORY;
437 GST_MINI_OBJECT_FLAGS (dest) =
438 (GST_MINI_OBJECT_FLAGS (src) & flags_mask) |
439 (GST_MINI_OBJECT_FLAGS (dest) & ~flags_mask);
442 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
444 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
445 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
446 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
447 if (size == bufsize) {
448 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
449 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
452 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
453 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
454 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
455 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
456 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
460 if (flags & GST_BUFFER_COPY_MEMORY) {
461 gsize skip, left, len, dest_len, i, bsize;
464 deep = flags & GST_BUFFER_COPY_DEEP;
466 len = GST_BUFFER_MEM_LEN (src);
467 dest_len = GST_BUFFER_MEM_LEN (dest);
471 /* copy and make regions of the memory */
472 for (i = 0; i < len && left > 0; i++) {
473 GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
475 bsize = gst_memory_get_sizes (mem, NULL, NULL);
478 /* don't copy buffer */
481 GstMemory *newmem = NULL;
484 tocopy = MIN (bsize - skip, left);
486 if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
487 /* we need to clip something */
488 newmem = gst_memory_share (mem, skip, tocopy);
490 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
495 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
496 /* deep copy or we're not allowed to share this memory
497 * between buffers, always copy then */
498 newmem = gst_memory_copy (mem, skip, tocopy);
500 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
503 } else if (!newmem) {
504 newmem = _memory_get_exclusive_reference (mem);
508 gst_buffer_remove_memory_range (dest, dest_len, -1);
512 _memory_add (dest, -1, newmem);
516 if (flags & GST_BUFFER_COPY_MERGE) {
519 len = GST_BUFFER_MEM_LEN (dest);
520 mem = _get_merged_memory (dest, 0, len);
522 gst_buffer_remove_memory_range (dest, dest_len, -1);
525 _replace_memory (dest, len, 0, len, mem);
529 if (flags & GST_BUFFER_COPY_META) {
530 /* NOTE: GstGLSyncMeta copying relies on the meta
531 * being copied now, after the buffer data,
532 * so this has to happen last */
533 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
534 GstMeta *meta = &walk->meta;
535 const GstMetaInfo *info = meta->info;
537 if (info->transform_func) {
538 GstMetaTransformCopy copy_data;
540 copy_data.region = region;
541 copy_data.offset = offset;
542 copy_data.size = size;
544 if (!info->transform_func (dest, meta, src,
545 _gst_meta_transform_copy, ©_data)) {
546 GST_CAT_ERROR (GST_CAT_BUFFER,
547 "failed to copy meta %p of API type %s", meta,
548 g_type_name (info->api));
558 gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
562 g_return_val_if_fail (buffer != NULL, NULL);
564 /* create a fresh new buffer */
565 copy = gst_buffer_new ();
567 /* copy what the 'flags' want from our parent */
568 /* FIXME why we can't pass const to gst_buffer_copy_into() ? */
569 if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
570 gst_buffer_replace (©, NULL);
573 GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
579 _gst_buffer_copy (const GstBuffer * buffer)
581 return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
585 * gst_buffer_copy_deep:
586 * @buf: a #GstBuffer.
588 * Create a copy of the given buffer. This will make a newly allocated
589 * copy of the data the source buffer contains.
591 * Returns: (transfer full): a new copy of @buf.
596 gst_buffer_copy_deep (const GstBuffer * buffer)
598 return gst_buffer_copy_with_flags (buffer,
599 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
602 /* the default dispose function revives the buffer and returns it to the
603 * pool when there is a pool */
605 _gst_buffer_dispose (GstBuffer * buffer)
609 /* no pool, do free */
610 if ((pool = buffer->pool) == NULL)
613 /* keep the buffer alive */
614 gst_buffer_ref (buffer);
615 /* return the buffer to the pool */
616 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
617 gst_buffer_pool_release_buffer (pool, buffer);
623 _gst_buffer_free (GstBuffer * buffer)
625 GstMetaItem *walk, *next;
629 g_return_if_fail (buffer != NULL);
631 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
634 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
635 GstMeta *meta = &walk->meta;
636 const GstMetaInfo *info = meta->info;
638 /* call free_func if any */
640 info->free_func (meta, buffer);
643 /* and free the slice */
644 g_slice_free1 (ITEM_SIZE (info), walk);
647 /* get the size, when unreffing the memory, we could also unref the buffer
649 msize = GST_BUFFER_SLICE_SIZE (buffer);
651 /* free our memory */
652 len = GST_BUFFER_MEM_LEN (buffer);
653 for (i = 0; i < len; i++) {
654 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
655 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
658 /* we set msize to 0 when the buffer is part of the memory block */
661 memset (buffer, 0xff, msize);
663 g_slice_free1 (msize, buffer);
665 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
670 gst_buffer_init (GstBufferImpl * buffer, gsize size)
672 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
673 (GstMiniObjectCopyFunction) _gst_buffer_copy,
674 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
675 (GstMiniObjectFreeFunction) _gst_buffer_free);
677 GST_BUFFER_SLICE_SIZE (buffer) = size;
679 GST_BUFFER (buffer)->pool = NULL;
680 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
681 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
682 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
683 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
684 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
686 GST_BUFFER_MEM_LEN (buffer) = 0;
687 GST_BUFFER_META (buffer) = NULL;
693 * Creates a newly allocated buffer without any data.
697 * Returns: (transfer full): the new #GstBuffer.
700 gst_buffer_new (void)
702 GstBufferImpl *newbuf;
704 newbuf = g_slice_new (GstBufferImpl);
705 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
707 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
709 return GST_BUFFER_CAST (newbuf);
713 * gst_buffer_new_allocate:
714 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
716 * @size: the size in bytes of the new buffer's data.
717 * @params: (transfer none) (allow-none): optional parameters
719 * Tries to create a newly allocated buffer with data of the given size and
720 * extra parameters from @allocator. If the requested amount of memory can't be
721 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
723 * When @allocator is %NULL, the default memory allocator will be used.
725 * Note that when @size == 0, the buffer will not have memory associated with it.
729 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
730 * the memory couldn't be allocated.
733 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
734 GstAllocationParams * params)
745 mem = gst_allocator_alloc (allocator, size, params);
746 if (G_UNLIKELY (mem == NULL))
752 newbuf = gst_buffer_new ();
755 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
756 _memory_add (newbuf, -1, mem);
759 GST_CAT_LOG (GST_CAT_BUFFER,
760 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
765 asize = sizeof (GstBufferImpl) + size;
766 data = g_slice_alloc (asize);
767 if (G_UNLIKELY (data == NULL))
770 newbuf = GST_BUFFER_CAST (data);
772 gst_buffer_init ((GstBufferImpl *) data, asize);
774 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
776 _memory_add (newbuf, -1, mem, TRUE);
781 /* allocate memory and buffer, it might be interesting to do this but there
782 * are many complications. We need to keep the memory mapped to access the
783 * buffer fields and the memory for the buffer might be just very slow. We
784 * also need to do some more magic to get the alignment right. */
785 asize = sizeof (GstBufferImpl) + size;
786 mem = gst_allocator_alloc (allocator, asize, align);
787 if (G_UNLIKELY (mem == NULL))
790 /* map the data part and init the buffer in it, set the buffer size to 0 so
791 * that a finalize won't free the buffer */
792 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
793 gst_buffer_init ((GstBufferImpl *) data, 0);
794 gst_memory_unmap (mem);
796 /* strip off the buffer */
797 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
799 newbuf = GST_BUFFER_CAST (data);
800 GST_BUFFER_BUFMEM (newbuf) = mem;
803 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
805 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
812 GST_CAT_WARNING (GST_CAT_BUFFER,
813 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
819 * gst_buffer_new_wrapped_full:
820 * @flags: #GstMemoryFlags
821 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
822 * @maxsize: allocated size of @data
823 * @offset: offset in @data
824 * @size: size of valid data
825 * @user_data: (allow-none): user_data
826 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
828 * Allocate a new buffer that wraps the given memory. @data must point to
829 * @maxsize of memory, the wrapped buffer will have the region from @offset and
832 * When the buffer is destroyed, @notify will be called with @user_data.
834 * The prefix/padding must be filled with 0 if @flags contains
835 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
837 * Returns: (transfer full): a new #GstBuffer
840 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
841 gsize maxsize, gsize offset, gsize size, gpointer user_data,
842 GDestroyNotify notify)
847 newbuf = gst_buffer_new ();
849 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
851 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
852 _memory_add (newbuf, -1, mem);
853 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
859 * gst_buffer_new_wrapped:
860 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
861 * @size: allocated size of @data
863 * Creates a new buffer that wraps the given @data. The memory will be freed
864 * with g_free and will be marked writable.
868 * Returns: (transfer full): a new #GstBuffer
871 gst_buffer_new_wrapped (gpointer data, gsize size)
873 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
877 * gst_buffer_n_memory:
878 * @buffer: a #GstBuffer.
880 * Get the amount of memory blocks that this buffer has. This amount is never
881 * larger than what gst_buffer_get_max_memory() returns.
883 * Returns: (transfer full): the amount of memory block in this buffer.
886 gst_buffer_n_memory (GstBuffer * buffer)
888 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
890 return GST_BUFFER_MEM_LEN (buffer);
894 * gst_buffer_prepend_memory:
895 * @buffer: a #GstBuffer.
896 * @mem: (transfer full): a #GstMemory.
898 * Prepend the memory block @mem to @buffer. This function takes
899 * ownership of @mem and thus doesn't increase its refcount.
901 * This function is identical to gst_buffer_insert_memory() with an index of 0.
902 * See gst_buffer_insert_memory() for more details.
905 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
907 gst_buffer_insert_memory (buffer, 0, mem);
911 * gst_buffer_append_memory:
912 * @buffer: a #GstBuffer.
913 * @mem: (transfer full): a #GstMemory.
915 * Append the memory block @mem to @buffer. This function takes
916 * ownership of @mem and thus doesn't increase its refcount.
918 * This function is identical to gst_buffer_insert_memory() with an index of -1.
919 * See gst_buffer_insert_memory() for more details.
922 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
924 gst_buffer_insert_memory (buffer, -1, mem);
928 * gst_buffer_insert_memory:
929 * @buffer: a #GstBuffer.
930 * @idx: the index to add the memory at, or -1 to append it to the end
931 * @mem: (transfer full): a #GstMemory.
933 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
934 * of @mem and thus doesn't increase its refcount.
936 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
937 * added, existing memory blocks will automatically be merged to make room for
941 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
945 g_return_if_fail (GST_IS_BUFFER (buffer));
946 g_return_if_fail (gst_buffer_is_writable (buffer));
947 g_return_if_fail (mem != NULL);
948 g_return_if_fail (idx == -1 ||
949 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
951 tmp = _memory_get_exclusive_reference (mem);
952 g_return_if_fail (tmp != NULL);
953 gst_memory_unref (mem);
954 _memory_add (buffer, idx, tmp);
958 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
961 GstMemory *mem, *mapped;
963 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
965 mapped = gst_memory_make_mapped (mem, info, flags);
968 /* memory changed, lock new memory */
969 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
970 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
971 /* unlock old memory */
972 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
973 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
975 gst_memory_unref (mem);
981 * gst_buffer_peek_memory:
982 * @buffer: a #GstBuffer.
985 * Get the memory block at @idx in @buffer. The memory block stays valid until
986 * the memory block in @buffer is removed, replaced or merged, typically with
987 * any call that modifies the memory in @buffer.
989 * Returns: (transfer none): the #GstMemory at @idx.
992 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
996 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
997 len = GST_BUFFER_MEM_LEN (buffer);
998 g_return_val_if_fail (idx < len, NULL);
1000 return GST_BUFFER_MEM_PTR (buffer, idx);
1004 * gst_buffer_get_memory:
1005 * @buffer: a #GstBuffer.
1008 * Get the memory block at index @idx in @buffer.
1010 * Returns: (transfer full): a #GstMemory that contains the data of the
1011 * memory block at @idx. Use gst_memory_unref () after usage.
1014 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
1016 return gst_buffer_get_memory_range (buffer, idx, 1);
1020 * gst_buffer_get_all_memory:
1021 * @buffer: a #GstBuffer.
1023 * Get all the memory block in @buffer. The memory blocks will be merged
1024 * into one large #GstMemory.
1026 * Returns: (transfer full): a #GstMemory that contains the merged memory.
1027 * Use gst_memory_unref () after usage.
1030 gst_buffer_get_all_memory (GstBuffer * buffer)
1032 return gst_buffer_get_memory_range (buffer, 0, -1);
1036 * gst_buffer_get_memory_range:
1037 * @buffer: a #GstBuffer.
1041 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
1042 * be merged into one large #GstMemory.
1044 * If @length is -1, all memory starting from @idx is merged.
1046 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
1047 * blocks starting at @idx. Use gst_memory_unref () after usage.
1050 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1054 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1056 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1057 len = GST_BUFFER_MEM_LEN (buffer);
1058 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1059 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1064 return _get_merged_memory (buffer, idx, length);
1068 * gst_buffer_replace_memory:
1069 * @buffer: a #GstBuffer.
1071 * @mem: (transfer full): a #GstMemory
1073 * Replaces the memory block at index @idx in @buffer with @mem.
1076 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1078 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1082 * gst_buffer_replace_all_memory:
1083 * @buffer: a #GstBuffer.
1084 * @mem: (transfer full): a #GstMemory
1086 * Replaces all memory in @buffer with @mem.
1089 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1091 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1095 * gst_buffer_replace_memory_range:
1096 * @buffer: a #GstBuffer.
1098 * @length: a length should not be 0
1099 * @mem: (transfer full): a #GstMemory
1101 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1103 * If @length is -1, all memory starting from @idx will be removed and
1104 * replaced with @mem.
1106 * @buffer should be writable.
1109 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1114 g_return_if_fail (GST_IS_BUFFER (buffer));
1115 g_return_if_fail (gst_buffer_is_writable (buffer));
1117 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1119 len = GST_BUFFER_MEM_LEN (buffer);
1120 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1121 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1126 _replace_memory (buffer, len, idx, length, mem);
1130 * gst_buffer_remove_memory:
1131 * @buffer: a #GstBuffer.
1134 * Remove the memory block in @b at index @i.
1137 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1139 gst_buffer_remove_memory_range (buffer, idx, 1);
1143 * gst_buffer_remove_all_memory:
1144 * @buffer: a #GstBuffer.
1146 * Remove all the memory blocks in @buffer.
1149 gst_buffer_remove_all_memory (GstBuffer * buffer)
1151 gst_buffer_remove_memory_range (buffer, 0, -1);
1155 * gst_buffer_remove_memory_range:
1156 * @buffer: a #GstBuffer.
1160 * Remove @length memory blocks in @buffer starting from @idx.
1162 * @length can be -1, in which case all memory starting from @idx is removed.
1165 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1169 g_return_if_fail (GST_IS_BUFFER (buffer));
1170 g_return_if_fail (gst_buffer_is_writable (buffer));
1172 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1174 len = GST_BUFFER_MEM_LEN (buffer);
1175 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1176 (length == -1 && idx < len) || length + idx <= len);
1181 _replace_memory (buffer, len, idx, length, NULL);
1185 * gst_buffer_find_memory:
1186 * @buffer: a #GstBuffer.
1187 * @offset: an offset
1189 * @idx: (out): pointer to index
1190 * @length: (out): pointer to length
1191 * @skip: (out): pointer to skip
1193 * Find the memory blocks that span @size bytes starting from @offset
1196 * When this function returns %TRUE, @idx will contain the index of the first
1197 * memory block where the byte for @offset can be found and @length contains the
1198 * number of memory blocks containing the @size remaining bytes. @skip contains
1199 * the number of bytes to skip in the memory block at @idx to get to the byte
1202 * @size can be -1 to get all the memory blocks after @idx.
1204 * Returns: %TRUE when @size bytes starting from @offset could be found in
1205 * @buffer and @idx, @length and @skip will be filled.
1208 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1209 guint * idx, guint * length, gsize * skip)
1211 guint i, len, found;
1213 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1214 g_return_val_if_fail (idx != NULL, FALSE);
1215 g_return_val_if_fail (length != NULL, FALSE);
1216 g_return_val_if_fail (skip != NULL, FALSE);
1218 len = GST_BUFFER_MEM_LEN (buffer);
1221 for (i = 0; i < len; i++) {
1225 mem = GST_BUFFER_MEM_PTR (buffer, i);
1226 s = gst_memory_get_sizes (mem, NULL, NULL);
1229 /* block before offset, or empty block, skip */
1232 /* block after offset */
1234 /* first block, remember index and offset */
1238 /* return remaining blocks */
1245 /* count the amount of found bytes */
1247 if (found >= size) {
1248 /* we have enough bytes */
1249 *length = i - *idx + 1;
1258 * gst_buffer_is_memory_range_writable:
1259 * @buffer: a #GstBuffer.
1261 * @length: a length should not be 0
1263 * Check if @length memory blocks in @buffer starting from @idx are writable.
1265 * @length can be -1 to check all the memory blocks after @idx.
1267 * Note that this function does not check if @buffer is writable, use
1268 * gst_buffer_is_writable() to check that if needed.
1270 * Returns: %TRUE if the memory range is writable
1275 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1279 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1281 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1283 len = GST_BUFFER_MEM_LEN (buffer);
1284 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1285 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1293 for (i = 0; i < len; i++) {
1294 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1301 * gst_buffer_is_all_memory_writable:
1302 * @buffer: a #GstBuffer.
1304 * Check if all memory blocks in @buffer are writable.
1306 * Note that this function does not check if @buffer is writable, use
1307 * gst_buffer_is_writable() to check that if needed.
1309 * Returns: %TRUE if all memory blocks in @buffer are writable
1314 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1316 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1320 * gst_buffer_get_sizes:
1321 * @buffer: a #GstBuffer.
1322 * @offset: (out) (allow-none): a pointer to the offset
1323 * @maxsize: (out) (allow-none): a pointer to the maxsize
1325 * Get the total size of the memory blocks in @b.
1327 * When not %NULL, @offset will contain the offset of the data in the
1328 * first memory block in @buffer and @maxsize will contain the sum of
1329 * the size and @offset and the amount of extra padding on the last
1330 * memory block. @offset and @maxsize can be used to resize the
1331 * buffer memory blocks with gst_buffer_resize().
1333 * Returns: total size of the memory blocks in @buffer.
1336 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1338 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1342 * gst_buffer_get_size:
1343 * @buffer: a #GstBuffer.
1345 * Get the total size of the memory blocks in @buffer.
1347 * Returns: total size of the memory blocks in @buffer.
1350 gst_buffer_get_size (GstBuffer * buffer)
1352 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1356 * gst_buffer_get_sizes_range:
1357 * @buffer: a #GstBuffer.
1360 * @offset: (out) (allow-none): a pointer to the offset
1361 * @maxsize: (out) (allow-none): a pointer to the maxsize
1363 * Get the total size of @length memory blocks stating from @idx in @buffer.
1365 * When not %NULL, @offset will contain the offset of the data in the
1366 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1367 * and @offset and the amount of extra padding on the memory block at @idx +
1369 * @offset and @maxsize can be used to resize the buffer memory blocks with
1370 * gst_buffer_resize_range().
1372 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1375 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1376 gsize * offset, gsize * maxsize)
1382 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1383 len = GST_BUFFER_MEM_LEN (buffer);
1384 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1385 (length == -1 && idx < len) || (length + idx <= len), 0);
1390 if (G_LIKELY (length == 1)) {
1392 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1393 size = gst_memory_get_sizes (mem, offset, maxsize);
1399 size = offs = extra = 0;
1400 for (i = idx; i < end; i++) {
1403 mem = GST_BUFFER_MEM_PTR (buffer, i);
1404 s = gst_memory_get_sizes (mem, &o, &ms);
1408 /* first size, take accumulated data before as the offset */
1412 /* save the amount of data after this block */
1413 extra = ms - (o + s);
1415 /* empty block, add as extra */
1422 *maxsize = offs + size + extra;
1428 * gst_buffer_resize:
1429 * @buffer: a #GstBuffer.
1430 * @offset: the offset adjustment
1431 * @size: the new size or -1 to just adjust the offset
1433 * Set the offset and total size of the memory blocks in @buffer.
1436 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1438 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1442 * gst_buffer_set_size:
1443 * @buffer: a #GstBuffer.
1444 * @size: the new size
1446 * Set the total size of the memory blocks in @buffer.
1449 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1451 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1455 * gst_buffer_resize_range:
1456 * @buffer: a #GstBuffer.
1459 * @offset: the offset adjustment
1460 * @size: the new size or -1 to just adjust the offset
1462 * Set the total size of the @length memory blocks starting at @idx in
1465 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1468 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1469 gssize offset, gssize size)
1472 gsize bsize, bufsize, bufoffs, bufmax;
1474 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1475 g_return_val_if_fail (size >= -1, FALSE);
1477 len = GST_BUFFER_MEM_LEN (buffer);
1478 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1479 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1484 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1486 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1487 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1488 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1490 /* we can't go back further than the current offset or past the end of the
1492 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1493 && bufoffs + offset <= bufmax), FALSE);
1495 g_return_val_if_fail (bufsize >= offset, FALSE);
1496 size = bufsize - offset;
1498 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1501 if (offset == 0 && size == bufsize)
1506 for (i = idx; i < end; i++) {
1510 mem = GST_BUFFER_MEM_PTR (buffer, i);
1511 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1514 /* last buffer always gets resized to the remaining size */
1517 /* shrink buffers before the offset */
1518 else if ((gssize) bsize <= offset) {
1520 noffs = offset - bsize;
1523 /* clip other buffers */
1525 left = MIN (bsize - offset, size);
1527 if (offset != 0 || left != bsize) {
1528 if (gst_memory_is_writable (mem)) {
1529 gst_memory_resize (mem, offset, left);
1531 GstMemory *newmem = NULL;
1533 if (!GST_MEMORY_IS_NO_SHARE (mem))
1534 newmem = gst_memory_share (mem, offset, left);
1537 newmem = gst_memory_copy (mem, offset, left);
1542 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1543 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1544 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1545 gst_memory_unref (mem);
1547 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1560 * @buffer: a #GstBuffer.
1561 * @info: (out): info about the mapping
1562 * @flags: flags for the mapping
1564 * This function fills @info with the #GstMapInfo of all merged memory
1565 * blocks in @buffer.
1567 * @flags describe the desired access of the memory. When @flags is
1568 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1569 * gst_buffer_is_writable()).
1571 * When @buffer is writable but the memory isn't, a writable copy will
1572 * automatically be created and returned. The readonly copy of the
1573 * buffer memory will then also be replaced with this writable copy.
1575 * The memory in @info should be unmapped with gst_buffer_unmap() after
1578 * Returns: %TRUE if the map succeeded and @info contains valid data.
1581 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1583 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1587 * gst_buffer_map_range:
1588 * @buffer: a #GstBuffer.
1591 * @info: (out): info about the mapping
1592 * @flags: flags for the mapping
1594 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1595 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1596 * from @idx are merged and mapped.
1598 * @flags describe the desired access of the memory. When @flags is
1599 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1600 * gst_buffer_is_writable()).
1602 * When @buffer is writable but the memory isn't, a writable copy will
1603 * automatically be created and returned. The readonly copy of the buffer memory
1604 * will then also be replaced with this writable copy.
1606 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1608 * Returns: %TRUE if the map succeeded and @info contains valid
1612 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1613 GstMapInfo * info, GstMapFlags flags)
1615 GstMemory *mem, *nmem;
1616 gboolean write, writable;
1619 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1620 g_return_val_if_fail (info != NULL, FALSE);
1621 len = GST_BUFFER_MEM_LEN (buffer);
1622 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1623 (length == -1 && idx < len) || (length > 0
1624 && length + idx <= len), FALSE);
1626 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1627 buffer, idx, length, flags);
1629 write = (flags & GST_MAP_WRITE) != 0;
1630 writable = gst_buffer_is_writable (buffer);
1632 /* check if we can write when asked for write access */
1633 if (G_UNLIKELY (write && !writable))
1639 mem = _get_merged_memory (buffer, idx, length);
1640 if (G_UNLIKELY (mem == NULL))
1643 /* now try to map */
1644 nmem = gst_memory_make_mapped (mem, info, flags);
1645 if (G_UNLIKELY (nmem == NULL))
1648 /* if we merged or when the map returned a different memory, we try to replace
1649 * the memory in the buffer */
1650 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1651 /* if the buffer is writable, replace the memory */
1653 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1656 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1657 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1666 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1667 g_critical ("write map requested on non-writable buffer");
1668 memset (info, 0, sizeof (GstMapInfo));
1673 /* empty buffer, we need to return NULL */
1674 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1675 memset (info, 0, sizeof (GstMapInfo));
1680 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1681 memset (info, 0, sizeof (GstMapInfo));
1688 * @buffer: a #GstBuffer.
1689 * @info: a #GstMapInfo
1691 * Release the memory previously mapped with gst_buffer_map().
1694 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1696 g_return_if_fail (GST_IS_BUFFER (buffer));
1697 g_return_if_fail (info != NULL);
1699 /* we need to check for NULL, it is possible that we tried to map a buffer
1700 * without memory and we should be able to unmap that fine */
1701 if (G_LIKELY (info->memory)) {
1702 gst_memory_unmap (info->memory, info);
1703 gst_memory_unref (info->memory);
1709 * @buffer: a #GstBuffer.
1710 * @offset: the offset to fill
1711 * @src: (array length=size) (element-type guint8): the source address
1712 * @size: the size to fill
1714 * Copy @size bytes from @src to @buffer at @offset.
1716 * Returns: The amount of bytes copied. This value can be lower than @size
1717 * when @buffer did not contain enough data.
1720 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1724 const guint8 *ptr = src;
1726 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1727 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1728 g_return_val_if_fail (src != NULL || size == 0, 0);
1730 GST_CAT_LOG (GST_CAT_BUFFER,
1731 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1734 len = GST_BUFFER_MEM_LEN (buffer);
1737 for (i = 0; i < len && left > 0; i++) {
1742 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1743 if (info.size > offset) {
1744 /* we have enough */
1745 tocopy = MIN (info.size - offset, left);
1746 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1751 /* offset past buffer, skip */
1752 offset -= info.size;
1754 gst_memory_unmap (mem, &info);
1760 * gst_buffer_extract:
1761 * @buffer: a #GstBuffer.
1762 * @offset: the offset to extract
1763 * @dest: the destination address
1764 * @size: the size to extract
1766 * Copy @size bytes starting from @offset in @buffer to @dest.
1768 * Returns: The amount of bytes extracted. This value can be lower than @size
1769 * when @buffer did not contain enough data.
1772 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1777 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1778 g_return_val_if_fail (dest != NULL, 0);
1780 GST_CAT_LOG (GST_CAT_BUFFER,
1781 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1784 len = GST_BUFFER_MEM_LEN (buffer);
1787 for (i = 0; i < len && left > 0; i++) {
1792 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1793 if (info.size > offset) {
1794 /* we have enough */
1795 tocopy = MIN (info.size - offset, left);
1796 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1801 /* offset past buffer, skip */
1802 offset -= info.size;
1804 gst_memory_unmap (mem, &info);
1810 * gst_buffer_memcmp:
1811 * @buffer: a #GstBuffer.
1812 * @offset: the offset in @buffer
1813 * @mem: (array length=size) (element-type guint8): the memory to compare
1814 * @size: the size to compare
1816 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1818 * Returns: 0 if the memory is equal.
1821 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1825 const guint8 *ptr = mem;
1828 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1829 g_return_val_if_fail (mem != NULL, 0);
1831 GST_CAT_LOG (GST_CAT_BUFFER,
1832 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1835 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1838 len = GST_BUFFER_MEM_LEN (buffer);
1840 for (i = 0; i < len && size > 0 && res == 0; i++) {
1845 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1846 if (info.size > offset) {
1847 /* we have enough */
1848 tocmp = MIN (info.size - offset, size);
1849 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1854 /* offset past buffer, skip */
1855 offset -= info.size;
1857 gst_memory_unmap (mem, &info);
1863 * gst_buffer_memset:
1864 * @buffer: a #GstBuffer.
1865 * @offset: the offset in @buffer
1866 * @val: the value to set
1867 * @size: the size to set
1869 * Fill @buf with @size bytes with @val starting from @offset.
1871 * Returns: The amount of bytes filled. This value can be lower than @size
1872 * when @buffer did not contain enough data.
1875 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1879 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1880 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1882 GST_CAT_LOG (GST_CAT_BUFFER,
1883 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1884 buffer, offset, val, size);
1886 len = GST_BUFFER_MEM_LEN (buffer);
1889 for (i = 0; i < len && left > 0; i++) {
1894 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1895 if (info.size > offset) {
1896 /* we have enough */
1897 toset = MIN (info.size - offset, left);
1898 memset ((guint8 *) info.data + offset, val, toset);
1902 /* offset past buffer, skip */
1903 offset -= info.size;
1905 gst_memory_unmap (mem, &info);
1911 * gst_buffer_copy_region:
1912 * @parent: a #GstBuffer.
1913 * @flags: the #GstBufferCopyFlags
1914 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1916 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
1919 * Creates a sub-buffer from @parent at @offset and @size.
1920 * This sub-buffer uses the actual memory space of the parent buffer.
1921 * This function will copy the offset and timestamp fields when the
1922 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1923 * #GST_BUFFER_OFFSET_NONE.
1924 * If @offset equals 0 and @size equals the total size of @buffer, the
1925 * duration and offset end fields are also copied. If not they will be set
1926 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1930 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
1934 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1935 gsize offset, gsize size)
1939 g_return_val_if_fail (buffer != NULL, NULL);
1941 /* create the new buffer */
1942 copy = gst_buffer_new ();
1944 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1945 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1947 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1948 gst_buffer_replace (©, NULL);
1954 * gst_buffer_append:
1955 * @buf1: (transfer full): the first source #GstBuffer to append.
1956 * @buf2: (transfer full): the second source #GstBuffer to append.
1958 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1959 * concatenation of the memory of @buf1 and @buf2.
1961 * Returns: (transfer full): the new #GstBuffer that contains the memory
1962 * of the two source buffers.
1965 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1967 return gst_buffer_append_region (buf1, buf2, 0, -1);
1971 * gst_buffer_append_region:
1972 * @buf1: (transfer full): the first source #GstBuffer to append.
1973 * @buf2: (transfer full): the second source #GstBuffer to append.
1974 * @offset: the offset in @buf2
1975 * @size: the size or -1 of @buf2
1977 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1978 * contain a concatenation of the memory of @buf1 and the requested region of
1981 * Returns: (transfer full): the new #GstBuffer that contains the memory
1982 * of the two source buffers.
1985 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
1990 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1991 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1993 buf1 = gst_buffer_make_writable (buf1);
1994 buf2 = gst_buffer_make_writable (buf2);
1996 gst_buffer_resize (buf2, offset, size);
1998 len = GST_BUFFER_MEM_LEN (buf2);
1999 for (i = 0; i < len; i++) {
2002 mem = GST_BUFFER_MEM_PTR (buf2, i);
2003 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
2004 _memory_add (buf1, -1, mem);
2007 GST_BUFFER_MEM_LEN (buf2) = 0;
2008 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
2009 gst_buffer_unref (buf2);
2015 * gst_buffer_get_meta:
2016 * @buffer: a #GstBuffer
2017 * @api: the #GType of an API
2019 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
2020 * returned. If multiple metadata with the given @api are attached to this
2021 * buffer only the first one is returned. To handle multiple metadata with a
2022 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
2023 * and check the meta->info.api member for the API type.
2025 * Returns: (transfer none) (nullable): the metadata for @api on
2029 gst_buffer_get_meta (GstBuffer * buffer, GType api)
2032 GstMeta *result = NULL;
2034 g_return_val_if_fail (buffer != NULL, NULL);
2035 g_return_val_if_fail (api != 0, NULL);
2037 /* find GstMeta of the requested API */
2038 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
2039 GstMeta *meta = &item->meta;
2040 if (meta->info->api == api) {
2049 * gst_buffer_add_meta:
2050 * @buffer: a #GstBuffer
2051 * @info: a #GstMetaInfo
2052 * @params: params for @info
2054 * Add metadata for @info to @buffer using the parameters in @params.
2056 * Returns: (transfer none): the metadata for the api in @info on @buffer.
2059 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2063 GstMeta *result = NULL;
2066 g_return_val_if_fail (buffer != NULL, NULL);
2067 g_return_val_if_fail (info != NULL, NULL);
2068 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2070 /* create a new slice */
2071 size = ITEM_SIZE (info);
2072 item = g_slice_alloc (size);
2073 result = &item->meta;
2074 result->info = info;
2075 result->flags = GST_META_FLAG_NONE;
2077 GST_CAT_DEBUG (GST_CAT_BUFFER,
2078 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2079 g_type_name (info->type), info->size);
2081 /* call the init_func when needed */
2082 if (info->init_func)
2083 if (!info->init_func (result, params, buffer))
2086 /* and add to the list of metadata */
2087 item->next = GST_BUFFER_META (buffer);
2088 GST_BUFFER_META (buffer) = item;
2094 g_slice_free1 (size, item);
2100 * gst_buffer_remove_meta:
2101 * @buffer: a #GstBuffer
2104 * Remove the metadata for @meta on @buffer.
2106 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2107 * metadata was on @buffer.
2110 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2112 GstMetaItem *walk, *prev;
2114 g_return_val_if_fail (buffer != NULL, FALSE);
2115 g_return_val_if_fail (meta != NULL, FALSE);
2116 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2117 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2120 /* find the metadata and delete */
2121 prev = GST_BUFFER_META (buffer);
2122 for (walk = prev; walk; walk = walk->next) {
2123 GstMeta *m = &walk->meta;
2125 const GstMetaInfo *info = meta->info;
2127 /* remove from list */
2128 if (GST_BUFFER_META (buffer) == walk)
2129 GST_BUFFER_META (buffer) = walk->next;
2131 prev->next = walk->next;
2132 /* call free_func if any */
2133 if (info->free_func)
2134 info->free_func (m, buffer);
2136 /* and free the slice */
2137 g_slice_free1 (ITEM_SIZE (info), walk);
2142 return walk != NULL;
2146 * gst_buffer_iterate_meta:
2147 * @buffer: a #GstBuffer
2148 * @state: an opaque state pointer
2150 * Retrieve the next #GstMeta after @current. If @state points
2151 * to %NULL, the first metadata is returned.
2153 * @state will be updated with an opaque state pointer
2155 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2156 * when there are no more items.
2159 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2163 g_return_val_if_fail (buffer != NULL, NULL);
2164 g_return_val_if_fail (state != NULL, NULL);
2166 meta = (GstMetaItem **) state;
2168 /* state NULL, move to first item */
2169 *meta = GST_BUFFER_META (buffer);
2171 /* state !NULL, move to next item in list */
2172 *meta = (*meta)->next;
2175 return &(*meta)->meta;
2181 * gst_buffer_foreach_meta:
2182 * @buffer: a #GstBuffer
2183 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2184 * @user_data: (closure): user data passed to @func
2186 * Call @func with @user_data for each meta in @buffer.
2188 * @func can modify the passed meta pointer or its contents. The return value
2189 * of @func define if this function returns or if the remaining metadata items
2190 * in the buffer should be skipped.
2192 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2195 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2198 GstMetaItem *walk, *prev, *next;
2199 gboolean res = TRUE;
2201 g_return_val_if_fail (buffer != NULL, FALSE);
2202 g_return_val_if_fail (func != NULL, FALSE);
2204 /* find the metadata and delete */
2205 prev = GST_BUFFER_META (buffer);
2206 for (walk = prev; walk; walk = next) {
2209 m = new = &walk->meta;
2212 res = func (buffer, &new, user_data);
2215 const GstMetaInfo *info = m->info;
2217 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2218 g_type_name (info->type));
2220 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2221 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2224 /* remove from list */
2225 if (GST_BUFFER_META (buffer) == walk)
2226 GST_BUFFER_META (buffer) = next;
2230 /* call free_func if any */
2231 if (info->free_func)
2232 info->free_func (m, buffer);
2234 /* and free the slice */
2235 g_slice_free1 (ITEM_SIZE (info), walk);
2244 * gst_buffer_extract_dup:
2245 * @buffer: a #GstBuffer
2246 * @offset: the offset to extract
2247 * @size: the size to extract
2248 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2249 * the destination array will be written.
2250 * @dest_size: (out): A location where the size of @dest can be written
2252 * Extracts a copy of at most @size bytes the data at @offset into a #GBytes.
2253 * @dest must be freed using g_free() when done.
2259 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2260 gpointer * dest, gsize * dest_size)
2264 real_size = gst_buffer_get_size (buffer);
2266 *dest = g_malloc (MIN (real_size - offset, size));
2268 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);
2271 GST_DEBUG_CATEGORY (gst_parent_buffer_meta_debug);
2274 * gst_buffer_add_parent_buffer_meta:
2275 * @buffer: (transfer none): a #GstBuffer
2276 * @ref: (transfer none): a #GstBuffer to ref
2278 * Add a #GstParentBufferMeta to @buffer that holds a reference on
2279 * @ref until the buffer is freed.
2281 * Returns: (transfer none): The #GstParentBufferMeta that was added to the buffer
2285 GstParentBufferMeta *
2286 gst_buffer_add_parent_buffer_meta (GstBuffer * buffer, GstBuffer * ref)
2288 GstParentBufferMeta *meta;
2290 g_return_val_if_fail (GST_IS_BUFFER (ref), NULL);
2293 (GstParentBufferMeta *) gst_buffer_add_meta (buffer,
2294 GST_PARENT_BUFFER_META_INFO, NULL);
2299 meta->buffer = gst_buffer_ref (ref);
2305 _gst_parent_buffer_meta_transform (GstBuffer * dest, GstMeta * meta,
2306 GstBuffer * buffer, GQuark type, gpointer data)
2308 GstParentBufferMeta *dmeta, *smeta;
2310 smeta = (GstParentBufferMeta *) meta;
2312 if (GST_META_TRANSFORM_IS_COPY (type)) {
2313 /* copy over the reference to the parent buffer.
2314 * Usually, this meta means we need to keep the parent buffer
2315 * alive because one of the child memories is in use, which
2316 * might not be the case if memory is deep copied or sub-regioned,
2317 * but we can't tell, so keep the meta */
2318 dmeta = gst_buffer_add_parent_buffer_meta (dest, smeta->buffer);
2322 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2323 "copy buffer reference metadata");
2329 _gst_parent_buffer_meta_free (GstParentBufferMeta * parent_meta,
2332 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2333 "Dropping reference on buffer %p", parent_meta->buffer);
2334 gst_buffer_unref (parent_meta->buffer);
2338 _gst_parent_buffer_meta_init (GstParentBufferMeta * parent_meta,
2339 gpointer params, GstBuffer * buffer)
2341 static volatile gsize _init;
2343 if (g_once_init_enter (&_init)) {
2344 GST_DEBUG_CATEGORY_INIT (gst_parent_buffer_meta_debug, "glbufferrefmeta", 0,
2346 g_once_init_leave (&_init, 1);
2349 parent_meta->buffer = NULL;
2355 gst_parent_buffer_meta_api_get_type (void)
2357 static volatile GType type = 0;
2358 static const gchar *tags[] = { NULL };
2360 if (g_once_init_enter (&type)) {
2361 GType _type = gst_meta_api_type_register ("GstParentBufferMetaAPI", tags);
2362 g_once_init_leave (&type, _type);
2369 * gst_parent_buffer_meta_get_info:
2371 * Get the global #GstMetaInfo describing the #GstParentBufferMeta meta.
2373 * Returns: (transfer none): The #GstMetaInfo
2378 gst_parent_buffer_meta_get_info (void)
2380 static const GstMetaInfo *meta_info = NULL;
2382 if (g_once_init_enter (&meta_info)) {
2383 const GstMetaInfo *meta =
2384 gst_meta_register (gst_parent_buffer_meta_api_get_type (),
2385 "GstParentBufferMeta",
2386 sizeof (GstParentBufferMeta),
2387 (GstMetaInitFunction) _gst_parent_buffer_meta_init,
2388 (GstMetaFreeFunction) _gst_parent_buffer_meta_free,
2389 _gst_parent_buffer_meta_transform);
2390 g_once_init_leave (&meta_info, meta);