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.
36 * |[<!-- language="C" -->
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 /* Don't copy memory metas if we only copied part of the buffer, didn't
538 * copy memories or merged memories. In all these cases the memory
539 * structure has changed and the memory meta becomes meaningless.
541 if ((region || !(flags & GST_BUFFER_COPY_MEMORY)
542 || (flags & GST_BUFFER_COPY_MERGE))
543 && gst_meta_api_type_has_tag (info->api, _gst_meta_tag_memory)) {
544 GST_CAT_DEBUG (GST_CAT_BUFFER,
545 "don't copy memory meta %p of API type %s", meta,
546 g_type_name (info->api));
547 } else if (info->transform_func) {
548 GstMetaTransformCopy copy_data;
550 copy_data.region = region;
551 copy_data.offset = offset;
552 copy_data.size = size;
554 if (!info->transform_func (dest, meta, src,
555 _gst_meta_transform_copy, ©_data)) {
556 GST_CAT_ERROR (GST_CAT_BUFFER,
557 "failed to copy meta %p of API type %s", meta,
558 g_type_name (info->api));
568 gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
572 g_return_val_if_fail (buffer != NULL, NULL);
574 /* create a fresh new buffer */
575 copy = gst_buffer_new ();
577 /* copy what the 'flags' want from our parent */
578 /* FIXME why we can't pass const to gst_buffer_copy_into() ? */
579 if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
580 gst_buffer_replace (©, NULL);
583 GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
589 _gst_buffer_copy (const GstBuffer * buffer)
591 return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
595 * gst_buffer_copy_deep:
596 * @buf: a #GstBuffer.
598 * Create a copy of the given buffer. This will make a newly allocated
599 * copy of the data the source buffer contains.
601 * Returns: (transfer full): a new copy of @buf.
606 gst_buffer_copy_deep (const GstBuffer * buffer)
608 return gst_buffer_copy_with_flags (buffer,
609 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
612 /* the default dispose function revives the buffer and returns it to the
613 * pool when there is a pool */
615 _gst_buffer_dispose (GstBuffer * buffer)
619 /* no pool, do free */
620 if ((pool = buffer->pool) == NULL)
623 /* keep the buffer alive */
624 gst_buffer_ref (buffer);
625 /* return the buffer to the pool */
626 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
627 gst_buffer_pool_release_buffer (pool, buffer);
633 _gst_buffer_free (GstBuffer * buffer)
635 GstMetaItem *walk, *next;
639 g_return_if_fail (buffer != NULL);
641 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
644 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
645 GstMeta *meta = &walk->meta;
646 const GstMetaInfo *info = meta->info;
648 /* call free_func if any */
650 info->free_func (meta, buffer);
653 /* and free the slice */
654 g_slice_free1 (ITEM_SIZE (info), walk);
657 /* get the size, when unreffing the memory, we could also unref the buffer
659 msize = GST_BUFFER_SLICE_SIZE (buffer);
661 /* free our memory */
662 len = GST_BUFFER_MEM_LEN (buffer);
663 for (i = 0; i < len; i++) {
664 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
665 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
668 /* we set msize to 0 when the buffer is part of the memory block */
671 memset (buffer, 0xff, msize);
673 g_slice_free1 (msize, buffer);
675 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
680 gst_buffer_init (GstBufferImpl * buffer, gsize size)
682 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
683 (GstMiniObjectCopyFunction) _gst_buffer_copy,
684 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
685 (GstMiniObjectFreeFunction) _gst_buffer_free);
687 GST_BUFFER_SLICE_SIZE (buffer) = size;
689 GST_BUFFER (buffer)->pool = NULL;
690 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
691 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
692 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
693 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
694 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
696 GST_BUFFER_MEM_LEN (buffer) = 0;
697 GST_BUFFER_META (buffer) = NULL;
703 * Creates a newly allocated buffer without any data.
707 * Returns: (transfer full): the new #GstBuffer.
710 gst_buffer_new (void)
712 GstBufferImpl *newbuf;
714 newbuf = g_slice_new (GstBufferImpl);
715 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
717 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
719 return GST_BUFFER_CAST (newbuf);
723 * gst_buffer_new_allocate:
724 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
726 * @size: the size in bytes of the new buffer's data.
727 * @params: (transfer none) (allow-none): optional parameters
729 * Tries to create a newly allocated buffer with data of the given size and
730 * extra parameters from @allocator. If the requested amount of memory can't be
731 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
733 * When @allocator is %NULL, the default memory allocator will be used.
735 * Note that when @size == 0, the buffer will not have memory associated with it.
739 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
740 * the memory couldn't be allocated.
743 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
744 GstAllocationParams * params)
755 mem = gst_allocator_alloc (allocator, size, params);
756 if (G_UNLIKELY (mem == NULL))
762 newbuf = gst_buffer_new ();
765 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
766 _memory_add (newbuf, -1, mem);
769 GST_CAT_LOG (GST_CAT_BUFFER,
770 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
775 asize = sizeof (GstBufferImpl) + size;
776 data = g_slice_alloc (asize);
777 if (G_UNLIKELY (data == NULL))
780 newbuf = GST_BUFFER_CAST (data);
782 gst_buffer_init ((GstBufferImpl *) data, asize);
784 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
786 _memory_add (newbuf, -1, mem, TRUE);
791 /* allocate memory and buffer, it might be interesting to do this but there
792 * are many complications. We need to keep the memory mapped to access the
793 * buffer fields and the memory for the buffer might be just very slow. We
794 * also need to do some more magic to get the alignment right. */
795 asize = sizeof (GstBufferImpl) + size;
796 mem = gst_allocator_alloc (allocator, asize, align);
797 if (G_UNLIKELY (mem == NULL))
800 /* map the data part and init the buffer in it, set the buffer size to 0 so
801 * that a finalize won't free the buffer */
802 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
803 gst_buffer_init ((GstBufferImpl *) data, 0);
804 gst_memory_unmap (mem);
806 /* strip off the buffer */
807 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
809 newbuf = GST_BUFFER_CAST (data);
810 GST_BUFFER_BUFMEM (newbuf) = mem;
813 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
815 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
822 GST_CAT_WARNING (GST_CAT_BUFFER,
823 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
829 * gst_buffer_new_wrapped_full:
830 * @flags: #GstMemoryFlags
831 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
832 * @maxsize: allocated size of @data
833 * @offset: offset in @data
834 * @size: size of valid data
835 * @user_data: (allow-none): user_data
836 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
838 * Allocate a new buffer that wraps the given memory. @data must point to
839 * @maxsize of memory, the wrapped buffer will have the region from @offset and
842 * When the buffer is destroyed, @notify will be called with @user_data.
844 * The prefix/padding must be filled with 0 if @flags contains
845 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
847 * Returns: (transfer full): a new #GstBuffer
850 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
851 gsize maxsize, gsize offset, gsize size, gpointer user_data,
852 GDestroyNotify notify)
857 newbuf = gst_buffer_new ();
859 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
861 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
862 _memory_add (newbuf, -1, mem);
863 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
869 * gst_buffer_new_wrapped:
870 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
871 * @size: allocated size of @data
873 * Creates a new buffer that wraps the given @data. The memory will be freed
874 * with g_free and will be marked writable.
878 * Returns: (transfer full): a new #GstBuffer
881 gst_buffer_new_wrapped (gpointer data, gsize size)
883 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
887 * gst_buffer_n_memory:
888 * @buffer: a #GstBuffer.
890 * Get the amount of memory blocks that this buffer has. This amount is never
891 * larger than what gst_buffer_get_max_memory() returns.
893 * Returns: (transfer full): the amount of memory block in this buffer.
896 gst_buffer_n_memory (GstBuffer * buffer)
898 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
900 return GST_BUFFER_MEM_LEN (buffer);
904 * gst_buffer_prepend_memory:
905 * @buffer: a #GstBuffer.
906 * @mem: (transfer full): a #GstMemory.
908 * Prepend the memory block @mem to @buffer. This function takes
909 * ownership of @mem and thus doesn't increase its refcount.
911 * This function is identical to gst_buffer_insert_memory() with an index of 0.
912 * See gst_buffer_insert_memory() for more details.
915 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
917 gst_buffer_insert_memory (buffer, 0, mem);
921 * gst_buffer_append_memory:
922 * @buffer: a #GstBuffer.
923 * @mem: (transfer full): a #GstMemory.
925 * Append the memory block @mem to @buffer. This function takes
926 * ownership of @mem and thus doesn't increase its refcount.
928 * This function is identical to gst_buffer_insert_memory() with an index of -1.
929 * See gst_buffer_insert_memory() for more details.
932 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
934 gst_buffer_insert_memory (buffer, -1, mem);
938 * gst_buffer_insert_memory:
939 * @buffer: a #GstBuffer.
940 * @idx: the index to add the memory at, or -1 to append it to the end
941 * @mem: (transfer full): a #GstMemory.
943 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
944 * of @mem and thus doesn't increase its refcount.
946 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
947 * added, existing memory blocks will automatically be merged to make room for
951 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
955 g_return_if_fail (GST_IS_BUFFER (buffer));
956 g_return_if_fail (gst_buffer_is_writable (buffer));
957 g_return_if_fail (mem != NULL);
958 g_return_if_fail (idx == -1 ||
959 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
961 tmp = _memory_get_exclusive_reference (mem);
962 g_return_if_fail (tmp != NULL);
963 gst_memory_unref (mem);
964 _memory_add (buffer, idx, tmp);
968 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
971 GstMemory *mem, *mapped;
973 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
975 mapped = gst_memory_make_mapped (mem, info, flags);
978 /* memory changed, lock new memory */
979 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
980 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
981 /* unlock old memory */
982 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
983 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
985 gst_memory_unref (mem);
991 * gst_buffer_peek_memory:
992 * @buffer: a #GstBuffer.
995 * Get the memory block at @idx in @buffer. The memory block stays valid until
996 * the memory block in @buffer is removed, replaced or merged, typically with
997 * any call that modifies the memory in @buffer.
999 * Returns: (transfer none): the #GstMemory at @idx.
1002 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
1006 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1007 len = GST_BUFFER_MEM_LEN (buffer);
1008 g_return_val_if_fail (idx < len, NULL);
1010 return GST_BUFFER_MEM_PTR (buffer, idx);
1014 * gst_buffer_get_memory:
1015 * @buffer: a #GstBuffer.
1018 * Get the memory block at index @idx in @buffer.
1020 * Returns: (transfer full): a #GstMemory that contains the data of the
1021 * memory block at @idx. Use gst_memory_unref () after usage.
1024 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
1026 return gst_buffer_get_memory_range (buffer, idx, 1);
1030 * gst_buffer_get_all_memory:
1031 * @buffer: a #GstBuffer.
1033 * Get all the memory block in @buffer. The memory blocks will be merged
1034 * into one large #GstMemory.
1036 * Returns: (transfer full): a #GstMemory that contains the merged memory.
1037 * Use gst_memory_unref () after usage.
1040 gst_buffer_get_all_memory (GstBuffer * buffer)
1042 return gst_buffer_get_memory_range (buffer, 0, -1);
1046 * gst_buffer_get_memory_range:
1047 * @buffer: a #GstBuffer.
1051 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
1052 * be merged into one large #GstMemory.
1054 * If @length is -1, all memory starting from @idx is merged.
1056 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
1057 * blocks starting at @idx. Use gst_memory_unref () after usage.
1060 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1064 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1066 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1067 len = GST_BUFFER_MEM_LEN (buffer);
1068 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1069 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1074 return _get_merged_memory (buffer, idx, length);
1078 * gst_buffer_replace_memory:
1079 * @buffer: a #GstBuffer.
1081 * @mem: (transfer full): a #GstMemory
1083 * Replaces the memory block at index @idx in @buffer with @mem.
1086 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1088 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1092 * gst_buffer_replace_all_memory:
1093 * @buffer: a #GstBuffer.
1094 * @mem: (transfer full): a #GstMemory
1096 * Replaces all memory in @buffer with @mem.
1099 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1101 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1105 * gst_buffer_replace_memory_range:
1106 * @buffer: a #GstBuffer.
1108 * @length: a length should not be 0
1109 * @mem: (transfer full): a #GstMemory
1111 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1113 * If @length is -1, all memory starting from @idx will be removed and
1114 * replaced with @mem.
1116 * @buffer should be writable.
1119 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1124 g_return_if_fail (GST_IS_BUFFER (buffer));
1125 g_return_if_fail (gst_buffer_is_writable (buffer));
1127 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1129 len = GST_BUFFER_MEM_LEN (buffer);
1130 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1131 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1136 _replace_memory (buffer, len, idx, length, mem);
1140 * gst_buffer_remove_memory:
1141 * @buffer: a #GstBuffer.
1144 * Remove the memory block in @b at index @i.
1147 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1149 gst_buffer_remove_memory_range (buffer, idx, 1);
1153 * gst_buffer_remove_all_memory:
1154 * @buffer: a #GstBuffer.
1156 * Remove all the memory blocks in @buffer.
1159 gst_buffer_remove_all_memory (GstBuffer * buffer)
1161 gst_buffer_remove_memory_range (buffer, 0, -1);
1165 * gst_buffer_remove_memory_range:
1166 * @buffer: a #GstBuffer.
1170 * Remove @length memory blocks in @buffer starting from @idx.
1172 * @length can be -1, in which case all memory starting from @idx is removed.
1175 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1179 g_return_if_fail (GST_IS_BUFFER (buffer));
1180 g_return_if_fail (gst_buffer_is_writable (buffer));
1182 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1184 len = GST_BUFFER_MEM_LEN (buffer);
1185 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1186 (length == -1 && idx < len) || length + idx <= len);
1191 _replace_memory (buffer, len, idx, length, NULL);
1195 * gst_buffer_find_memory:
1196 * @buffer: a #GstBuffer.
1197 * @offset: an offset
1199 * @idx: (out): pointer to index
1200 * @length: (out): pointer to length
1201 * @skip: (out): pointer to skip
1203 * Find the memory blocks that span @size bytes starting from @offset
1206 * When this function returns %TRUE, @idx will contain the index of the first
1207 * memory block where the byte for @offset can be found and @length contains the
1208 * number of memory blocks containing the @size remaining bytes. @skip contains
1209 * the number of bytes to skip in the memory block at @idx to get to the byte
1212 * @size can be -1 to get all the memory blocks after @idx.
1214 * Returns: %TRUE when @size bytes starting from @offset could be found in
1215 * @buffer and @idx, @length and @skip will be filled.
1218 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1219 guint * idx, guint * length, gsize * skip)
1221 guint i, len, found;
1223 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1224 g_return_val_if_fail (idx != NULL, FALSE);
1225 g_return_val_if_fail (length != NULL, FALSE);
1226 g_return_val_if_fail (skip != NULL, FALSE);
1228 len = GST_BUFFER_MEM_LEN (buffer);
1231 for (i = 0; i < len; i++) {
1235 mem = GST_BUFFER_MEM_PTR (buffer, i);
1236 s = gst_memory_get_sizes (mem, NULL, NULL);
1239 /* block before offset, or empty block, skip */
1242 /* block after offset */
1244 /* first block, remember index and offset */
1248 /* return remaining blocks */
1255 /* count the amount of found bytes */
1257 if (found >= size) {
1258 /* we have enough bytes */
1259 *length = i - *idx + 1;
1268 * gst_buffer_is_memory_range_writable:
1269 * @buffer: a #GstBuffer.
1271 * @length: a length should not be 0
1273 * Check if @length memory blocks in @buffer starting from @idx are writable.
1275 * @length can be -1 to check all the memory blocks after @idx.
1277 * Note that this function does not check if @buffer is writable, use
1278 * gst_buffer_is_writable() to check that if needed.
1280 * Returns: %TRUE if the memory range is writable
1285 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1289 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1291 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1293 len = GST_BUFFER_MEM_LEN (buffer);
1294 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1295 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1303 for (i = 0; i < len; i++) {
1304 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1311 * gst_buffer_is_all_memory_writable:
1312 * @buffer: a #GstBuffer.
1314 * Check if all memory blocks in @buffer are writable.
1316 * Note that this function does not check if @buffer is writable, use
1317 * gst_buffer_is_writable() to check that if needed.
1319 * Returns: %TRUE if all memory blocks in @buffer are writable
1324 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1326 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1330 * gst_buffer_get_sizes:
1331 * @buffer: a #GstBuffer.
1332 * @offset: (out) (allow-none): a pointer to the offset
1333 * @maxsize: (out) (allow-none): a pointer to the maxsize
1335 * Get the total size of the memory blocks in @b.
1337 * When not %NULL, @offset will contain the offset of the data in the
1338 * first memory block in @buffer and @maxsize will contain the sum of
1339 * the size and @offset and the amount of extra padding on the last
1340 * memory block. @offset and @maxsize can be used to resize the
1341 * buffer memory blocks with gst_buffer_resize().
1343 * Returns: total size of the memory blocks in @buffer.
1346 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1348 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1352 * gst_buffer_get_size:
1353 * @buffer: a #GstBuffer.
1355 * Get the total size of the memory blocks in @buffer.
1357 * Returns: total size of the memory blocks in @buffer.
1360 gst_buffer_get_size (GstBuffer * buffer)
1362 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1366 * gst_buffer_get_sizes_range:
1367 * @buffer: a #GstBuffer.
1370 * @offset: (out) (allow-none): a pointer to the offset
1371 * @maxsize: (out) (allow-none): a pointer to the maxsize
1373 * Get the total size of @length memory blocks stating from @idx in @buffer.
1375 * When not %NULL, @offset will contain the offset of the data in the
1376 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1377 * and @offset and the amount of extra padding on the memory block at @idx +
1379 * @offset and @maxsize can be used to resize the buffer memory blocks with
1380 * gst_buffer_resize_range().
1382 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1385 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1386 gsize * offset, gsize * maxsize)
1392 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1393 len = GST_BUFFER_MEM_LEN (buffer);
1394 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1395 (length == -1 && idx < len) || (length + idx <= len), 0);
1400 if (G_LIKELY (length == 1)) {
1402 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1403 size = gst_memory_get_sizes (mem, offset, maxsize);
1409 size = offs = extra = 0;
1410 for (i = idx; i < end; i++) {
1413 mem = GST_BUFFER_MEM_PTR (buffer, i);
1414 s = gst_memory_get_sizes (mem, &o, &ms);
1418 /* first size, take accumulated data before as the offset */
1422 /* save the amount of data after this block */
1423 extra = ms - (o + s);
1425 /* empty block, add as extra */
1432 *maxsize = offs + size + extra;
1438 * gst_buffer_resize:
1439 * @buffer: a #GstBuffer.
1440 * @offset: the offset adjustment
1441 * @size: the new size or -1 to just adjust the offset
1443 * Set the offset and total size of the memory blocks in @buffer.
1446 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1448 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1452 * gst_buffer_set_size:
1453 * @buffer: a #GstBuffer.
1454 * @size: the new size
1456 * Set the total size of the memory blocks in @buffer.
1459 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1461 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1465 * gst_buffer_resize_range:
1466 * @buffer: a #GstBuffer.
1469 * @offset: the offset adjustment
1470 * @size: the new size or -1 to just adjust the offset
1472 * Set the total size of the @length memory blocks starting at @idx in
1475 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1478 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1479 gssize offset, gssize size)
1482 gsize bsize, bufsize, bufoffs, bufmax;
1484 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1485 g_return_val_if_fail (size >= -1, FALSE);
1487 len = GST_BUFFER_MEM_LEN (buffer);
1488 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1489 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1494 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1496 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1497 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1498 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1500 /* we can't go back further than the current offset or past the end of the
1502 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1503 && bufoffs + offset <= bufmax), FALSE);
1505 g_return_val_if_fail (bufsize >= offset, FALSE);
1506 size = bufsize - offset;
1508 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1511 if (offset == 0 && size == bufsize)
1516 for (i = idx; i < end; i++) {
1520 mem = GST_BUFFER_MEM_PTR (buffer, i);
1521 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1524 /* last buffer always gets resized to the remaining size */
1527 /* shrink buffers before the offset */
1528 else if ((gssize) bsize <= offset) {
1530 noffs = offset - bsize;
1533 /* clip other buffers */
1535 left = MIN (bsize - offset, size);
1537 if (offset != 0 || left != bsize) {
1538 if (gst_memory_is_writable (mem)) {
1539 gst_memory_resize (mem, offset, left);
1541 GstMemory *newmem = NULL;
1543 if (!GST_MEMORY_IS_NO_SHARE (mem))
1544 newmem = gst_memory_share (mem, offset, left);
1547 newmem = gst_memory_copy (mem, offset, left);
1552 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1553 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1554 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1555 gst_memory_unref (mem);
1557 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1570 * @buffer: a #GstBuffer.
1571 * @info: (out): info about the mapping
1572 * @flags: flags for the mapping
1574 * This function fills @info with the #GstMapInfo of all merged memory
1575 * blocks in @buffer.
1577 * @flags describe the desired access of the memory. When @flags is
1578 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1579 * gst_buffer_is_writable()).
1581 * When @buffer is writable but the memory isn't, a writable copy will
1582 * automatically be created and returned. The readonly copy of the
1583 * buffer memory will then also be replaced with this writable copy.
1585 * The memory in @info should be unmapped with gst_buffer_unmap() after
1588 * Returns: %TRUE if the map succeeded and @info contains valid data.
1591 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1593 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1597 * gst_buffer_map_range:
1598 * @buffer: a #GstBuffer.
1601 * @info: (out): info about the mapping
1602 * @flags: flags for the mapping
1604 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1605 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1606 * from @idx are merged and mapped.
1608 * @flags describe the desired access of the memory. When @flags is
1609 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1610 * gst_buffer_is_writable()).
1612 * When @buffer is writable but the memory isn't, a writable copy will
1613 * automatically be created and returned. The readonly copy of the buffer memory
1614 * will then also be replaced with this writable copy.
1616 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1618 * Returns: %TRUE if the map succeeded and @info contains valid
1622 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1623 GstMapInfo * info, GstMapFlags flags)
1625 GstMemory *mem, *nmem;
1626 gboolean write, writable;
1629 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1630 g_return_val_if_fail (info != NULL, FALSE);
1631 len = GST_BUFFER_MEM_LEN (buffer);
1632 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1633 (length == -1 && idx < len) || (length > 0
1634 && length + idx <= len), FALSE);
1636 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1637 buffer, idx, length, flags);
1639 write = (flags & GST_MAP_WRITE) != 0;
1640 writable = gst_buffer_is_writable (buffer);
1642 /* check if we can write when asked for write access */
1643 if (G_UNLIKELY (write && !writable))
1649 mem = _get_merged_memory (buffer, idx, length);
1650 if (G_UNLIKELY (mem == NULL))
1653 /* now try to map */
1654 nmem = gst_memory_make_mapped (mem, info, flags);
1655 if (G_UNLIKELY (nmem == NULL))
1658 /* if we merged or when the map returned a different memory, we try to replace
1659 * the memory in the buffer */
1660 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1661 /* if the buffer is writable, replace the memory */
1663 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1666 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1667 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1676 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1677 g_critical ("write map requested on non-writable buffer");
1678 memset (info, 0, sizeof (GstMapInfo));
1683 /* empty buffer, we need to return NULL */
1684 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1685 memset (info, 0, sizeof (GstMapInfo));
1690 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1691 memset (info, 0, sizeof (GstMapInfo));
1698 * @buffer: a #GstBuffer.
1699 * @info: a #GstMapInfo
1701 * Release the memory previously mapped with gst_buffer_map().
1704 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1706 g_return_if_fail (GST_IS_BUFFER (buffer));
1707 g_return_if_fail (info != NULL);
1709 /* we need to check for NULL, it is possible that we tried to map a buffer
1710 * without memory and we should be able to unmap that fine */
1711 if (G_LIKELY (info->memory)) {
1712 gst_memory_unmap (info->memory, info);
1713 gst_memory_unref (info->memory);
1719 * @buffer: a #GstBuffer.
1720 * @offset: the offset to fill
1721 * @src: (array length=size) (element-type guint8): the source address
1722 * @size: the size to fill
1724 * Copy @size bytes from @src to @buffer at @offset.
1726 * Returns: The amount of bytes copied. This value can be lower than @size
1727 * when @buffer did not contain enough data.
1730 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1734 const guint8 *ptr = src;
1736 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1737 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1738 g_return_val_if_fail (src != NULL || size == 0, 0);
1740 GST_CAT_LOG (GST_CAT_BUFFER,
1741 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1744 len = GST_BUFFER_MEM_LEN (buffer);
1747 for (i = 0; i < len && left > 0; i++) {
1752 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1753 if (info.size > offset) {
1754 /* we have enough */
1755 tocopy = MIN (info.size - offset, left);
1756 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1761 /* offset past buffer, skip */
1762 offset -= info.size;
1764 gst_memory_unmap (mem, &info);
1770 * gst_buffer_extract:
1771 * @buffer: a #GstBuffer.
1772 * @offset: the offset to extract
1773 * @dest: the destination address
1774 * @size: the size to extract
1776 * Copy @size bytes starting from @offset in @buffer to @dest.
1778 * Returns: The amount of bytes extracted. This value can be lower than @size
1779 * when @buffer did not contain enough data.
1782 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1787 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1788 g_return_val_if_fail (dest != NULL, 0);
1790 GST_CAT_LOG (GST_CAT_BUFFER,
1791 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1794 len = GST_BUFFER_MEM_LEN (buffer);
1797 for (i = 0; i < len && left > 0; i++) {
1802 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1803 if (info.size > offset) {
1804 /* we have enough */
1805 tocopy = MIN (info.size - offset, left);
1806 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1811 /* offset past buffer, skip */
1812 offset -= info.size;
1814 gst_memory_unmap (mem, &info);
1820 * gst_buffer_memcmp:
1821 * @buffer: a #GstBuffer.
1822 * @offset: the offset in @buffer
1823 * @mem: (array length=size) (element-type guint8): the memory to compare
1824 * @size: the size to compare
1826 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1828 * Returns: 0 if the memory is equal.
1831 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1835 const guint8 *ptr = mem;
1838 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1839 g_return_val_if_fail (mem != NULL, 0);
1841 GST_CAT_LOG (GST_CAT_BUFFER,
1842 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1845 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1848 len = GST_BUFFER_MEM_LEN (buffer);
1850 for (i = 0; i < len && size > 0 && res == 0; i++) {
1855 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1856 if (info.size > offset) {
1857 /* we have enough */
1858 tocmp = MIN (info.size - offset, size);
1859 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1864 /* offset past buffer, skip */
1865 offset -= info.size;
1867 gst_memory_unmap (mem, &info);
1873 * gst_buffer_memset:
1874 * @buffer: a #GstBuffer.
1875 * @offset: the offset in @buffer
1876 * @val: the value to set
1877 * @size: the size to set
1879 * Fill @buf with @size bytes with @val starting from @offset.
1881 * Returns: The amount of bytes filled. This value can be lower than @size
1882 * when @buffer did not contain enough data.
1885 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1889 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1890 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1892 GST_CAT_LOG (GST_CAT_BUFFER,
1893 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1894 buffer, offset, val, size);
1896 len = GST_BUFFER_MEM_LEN (buffer);
1899 for (i = 0; i < len && left > 0; i++) {
1904 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1905 if (info.size > offset) {
1906 /* we have enough */
1907 toset = MIN (info.size - offset, left);
1908 memset ((guint8 *) info.data + offset, val, toset);
1912 /* offset past buffer, skip */
1913 offset -= info.size;
1915 gst_memory_unmap (mem, &info);
1921 * gst_buffer_copy_region:
1922 * @parent: a #GstBuffer.
1923 * @flags: the #GstBufferCopyFlags
1924 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1926 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
1929 * Creates a sub-buffer from @parent at @offset and @size.
1930 * This sub-buffer uses the actual memory space of the parent buffer.
1931 * This function will copy the offset and timestamp fields when the
1932 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1933 * #GST_BUFFER_OFFSET_NONE.
1934 * If @offset equals 0 and @size equals the total size of @buffer, the
1935 * duration and offset end fields are also copied. If not they will be set
1936 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1940 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
1944 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1945 gsize offset, gsize size)
1949 g_return_val_if_fail (buffer != NULL, NULL);
1951 /* create the new buffer */
1952 copy = gst_buffer_new ();
1954 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1955 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1957 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1958 gst_buffer_replace (©, NULL);
1964 * gst_buffer_append:
1965 * @buf1: (transfer full): the first source #GstBuffer to append.
1966 * @buf2: (transfer full): the second source #GstBuffer to append.
1968 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1969 * concatenation of the memory of @buf1 and @buf2.
1971 * Returns: (transfer full): the new #GstBuffer that contains the memory
1972 * of the two source buffers.
1975 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1977 return gst_buffer_append_region (buf1, buf2, 0, -1);
1981 * gst_buffer_append_region:
1982 * @buf1: (transfer full): the first source #GstBuffer to append.
1983 * @buf2: (transfer full): the second source #GstBuffer to append.
1984 * @offset: the offset in @buf2
1985 * @size: the size or -1 of @buf2
1987 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1988 * contain a concatenation of the memory of @buf1 and the requested region of
1991 * Returns: (transfer full): the new #GstBuffer that contains the memory
1992 * of the two source buffers.
1995 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
2000 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
2001 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
2003 buf1 = gst_buffer_make_writable (buf1);
2004 buf2 = gst_buffer_make_writable (buf2);
2006 gst_buffer_resize (buf2, offset, size);
2008 len = GST_BUFFER_MEM_LEN (buf2);
2009 for (i = 0; i < len; i++) {
2012 mem = GST_BUFFER_MEM_PTR (buf2, i);
2013 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
2014 _memory_add (buf1, -1, mem);
2017 GST_BUFFER_MEM_LEN (buf2) = 0;
2018 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
2019 gst_buffer_unref (buf2);
2025 * gst_buffer_get_meta:
2026 * @buffer: a #GstBuffer
2027 * @api: the #GType of an API
2029 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
2030 * returned. If multiple metadata with the given @api are attached to this
2031 * buffer only the first one is returned. To handle multiple metadata with a
2032 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
2033 * and check the meta->info.api member for the API type.
2035 * Returns: (transfer none) (nullable): the metadata for @api on
2039 gst_buffer_get_meta (GstBuffer * buffer, GType api)
2042 GstMeta *result = NULL;
2044 g_return_val_if_fail (buffer != NULL, NULL);
2045 g_return_val_if_fail (api != 0, NULL);
2047 /* find GstMeta of the requested API */
2048 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
2049 GstMeta *meta = &item->meta;
2050 if (meta->info->api == api) {
2059 * gst_buffer_add_meta:
2060 * @buffer: a #GstBuffer
2061 * @info: a #GstMetaInfo
2062 * @params: params for @info
2064 * Add metadata for @info to @buffer using the parameters in @params.
2066 * Returns: (transfer none): the metadata for the api in @info on @buffer.
2069 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2073 GstMeta *result = NULL;
2076 g_return_val_if_fail (buffer != NULL, NULL);
2077 g_return_val_if_fail (info != NULL, NULL);
2078 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2080 /* create a new slice */
2081 size = ITEM_SIZE (info);
2082 item = g_slice_alloc (size);
2083 result = &item->meta;
2084 result->info = info;
2085 result->flags = GST_META_FLAG_NONE;
2087 GST_CAT_DEBUG (GST_CAT_BUFFER,
2088 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2089 g_type_name (info->type), info->size);
2091 /* call the init_func when needed */
2092 if (info->init_func)
2093 if (!info->init_func (result, params, buffer))
2096 /* and add to the list of metadata */
2097 item->next = GST_BUFFER_META (buffer);
2098 GST_BUFFER_META (buffer) = item;
2104 g_slice_free1 (size, item);
2110 * gst_buffer_remove_meta:
2111 * @buffer: a #GstBuffer
2114 * Remove the metadata for @meta on @buffer.
2116 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2117 * metadata was on @buffer.
2120 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2122 GstMetaItem *walk, *prev;
2124 g_return_val_if_fail (buffer != NULL, FALSE);
2125 g_return_val_if_fail (meta != NULL, FALSE);
2126 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2127 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2130 /* find the metadata and delete */
2131 prev = GST_BUFFER_META (buffer);
2132 for (walk = prev; walk; walk = walk->next) {
2133 GstMeta *m = &walk->meta;
2135 const GstMetaInfo *info = meta->info;
2137 /* remove from list */
2138 if (GST_BUFFER_META (buffer) == walk)
2139 GST_BUFFER_META (buffer) = walk->next;
2141 prev->next = walk->next;
2142 /* call free_func if any */
2143 if (info->free_func)
2144 info->free_func (m, buffer);
2146 /* and free the slice */
2147 g_slice_free1 (ITEM_SIZE (info), walk);
2152 return walk != NULL;
2156 * gst_buffer_iterate_meta:
2157 * @buffer: a #GstBuffer
2158 * @state: an opaque state pointer
2160 * Retrieve the next #GstMeta after @current. If @state points
2161 * to %NULL, the first metadata is returned.
2163 * @state will be updated with an opaque state pointer
2165 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2166 * when there are no more items.
2169 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2173 g_return_val_if_fail (buffer != NULL, NULL);
2174 g_return_val_if_fail (state != NULL, NULL);
2176 meta = (GstMetaItem **) state;
2178 /* state NULL, move to first item */
2179 *meta = GST_BUFFER_META (buffer);
2181 /* state !NULL, move to next item in list */
2182 *meta = (*meta)->next;
2185 return &(*meta)->meta;
2191 * gst_buffer_foreach_meta:
2192 * @buffer: a #GstBuffer
2193 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2194 * @user_data: (closure): user data passed to @func
2196 * Call @func with @user_data for each meta in @buffer.
2198 * @func can modify the passed meta pointer or its contents. The return value
2199 * of @func define if this function returns or if the remaining metadata items
2200 * in the buffer should be skipped.
2202 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2205 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2208 GstMetaItem *walk, *prev, *next;
2209 gboolean res = TRUE;
2211 g_return_val_if_fail (buffer != NULL, FALSE);
2212 g_return_val_if_fail (func != NULL, FALSE);
2214 /* find the metadata and delete */
2215 prev = GST_BUFFER_META (buffer);
2216 for (walk = prev; walk; walk = next) {
2219 m = new = &walk->meta;
2222 res = func (buffer, &new, user_data);
2225 const GstMetaInfo *info = m->info;
2227 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2228 g_type_name (info->type));
2230 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2231 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2234 /* remove from list */
2235 if (GST_BUFFER_META (buffer) == walk)
2236 GST_BUFFER_META (buffer) = next;
2240 /* call free_func if any */
2241 if (info->free_func)
2242 info->free_func (m, buffer);
2244 /* and free the slice */
2245 g_slice_free1 (ITEM_SIZE (info), walk);
2254 * gst_buffer_extract_dup:
2255 * @buffer: a #GstBuffer
2256 * @offset: the offset to extract
2257 * @size: the size to extract
2258 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2259 * the destination array will be written.
2260 * @dest_size: (out): A location where the size of @dest can be written
2262 * Extracts a copy of at most @size bytes the data at @offset into
2263 * newly-allocated memory. @dest must be freed using g_free() when done.
2269 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2270 gpointer * dest, gsize * dest_size)
2274 real_size = gst_buffer_get_size (buffer);
2276 *dest = g_malloc (MIN (real_size - offset, size));
2278 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);
2281 GST_DEBUG_CATEGORY_STATIC (gst_parent_buffer_meta_debug);
2284 * gst_buffer_add_parent_buffer_meta:
2285 * @buffer: (transfer none): a #GstBuffer
2286 * @ref: (transfer none): a #GstBuffer to ref
2288 * Add a #GstParentBufferMeta to @buffer that holds a reference on
2289 * @ref until the buffer is freed.
2291 * Returns: (transfer none): The #GstParentBufferMeta that was added to the buffer
2295 GstParentBufferMeta *
2296 gst_buffer_add_parent_buffer_meta (GstBuffer * buffer, GstBuffer * ref)
2298 GstParentBufferMeta *meta;
2300 g_return_val_if_fail (GST_IS_BUFFER (ref), NULL);
2303 (GstParentBufferMeta *) gst_buffer_add_meta (buffer,
2304 GST_PARENT_BUFFER_META_INFO, NULL);
2309 meta->buffer = gst_buffer_ref (ref);
2315 _gst_parent_buffer_meta_transform (GstBuffer * dest, GstMeta * meta,
2316 GstBuffer * buffer, GQuark type, gpointer data)
2318 GstParentBufferMeta *dmeta, *smeta;
2320 smeta = (GstParentBufferMeta *) meta;
2322 if (GST_META_TRANSFORM_IS_COPY (type)) {
2323 /* copy over the reference to the parent buffer.
2324 * Usually, this meta means we need to keep the parent buffer
2325 * alive because one of the child memories is in use, which
2326 * might not be the case if memory is deep copied or sub-regioned,
2327 * but we can't tell, so keep the meta */
2328 dmeta = gst_buffer_add_parent_buffer_meta (dest, smeta->buffer);
2332 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2333 "copy buffer reference metadata");
2335 /* return FALSE, if transform type is not supported */
2342 _gst_parent_buffer_meta_free (GstParentBufferMeta * parent_meta,
2345 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2346 "Dropping reference on buffer %p", parent_meta->buffer);
2347 gst_buffer_unref (parent_meta->buffer);
2351 _gst_parent_buffer_meta_init (GstParentBufferMeta * parent_meta,
2352 gpointer params, GstBuffer * buffer)
2354 static volatile gsize _init;
2356 if (g_once_init_enter (&_init)) {
2357 GST_DEBUG_CATEGORY_INIT (gst_parent_buffer_meta_debug, "parentbuffermeta",
2358 0, "parentbuffermeta");
2359 g_once_init_leave (&_init, 1);
2362 parent_meta->buffer = NULL;
2368 gst_parent_buffer_meta_api_get_type (void)
2370 static volatile GType type = 0;
2371 static const gchar *tags[] = { NULL };
2373 if (g_once_init_enter (&type)) {
2374 GType _type = gst_meta_api_type_register ("GstParentBufferMetaAPI", tags);
2375 g_once_init_leave (&type, _type);
2382 * gst_parent_buffer_meta_get_info:
2384 * Get the global #GstMetaInfo describing the #GstParentBufferMeta meta.
2386 * Returns: (transfer none): The #GstMetaInfo
2391 gst_parent_buffer_meta_get_info (void)
2393 static const GstMetaInfo *meta_info = NULL;
2395 if (g_once_init_enter (&meta_info)) {
2396 const GstMetaInfo *meta =
2397 gst_meta_register (gst_parent_buffer_meta_api_get_type (),
2398 "GstParentBufferMeta",
2399 sizeof (GstParentBufferMeta),
2400 (GstMetaInitFunction) _gst_parent_buffer_meta_init,
2401 (GstMetaFreeFunction) _gst_parent_buffer_meta_free,
2402 _gst_parent_buffer_meta_transform);
2403 g_once_init_leave (&meta_info, meta);