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 if (result == NULL || !gst_memory_map (result, &dinfo, GST_MAP_WRITE)) {
240 GST_CAT_ERROR (GST_CAT_BUFFER, "Failed to map memory writable");
242 gst_memory_unref (result);
249 for (i = idx; i < (idx + length) && left > 0; i++) {
250 if (!gst_memory_map (mem[i], &sinfo, GST_MAP_READ)) {
251 GST_CAT_ERROR (GST_CAT_BUFFER,
252 "buffer %p, idx %u, length %u failed to map readable", buffer,
254 gst_memory_unmap (result, &dinfo);
255 gst_memory_unref (result);
258 tocopy = MIN (sinfo.size, left);
259 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
260 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
261 tocopy, result, mem[i]);
262 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
265 gst_memory_unmap (mem[i], &sinfo);
267 gst_memory_unmap (result, &dinfo);
274 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
281 GST_CAT_LOG (GST_CAT_BUFFER,
282 "buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
285 /* unref old memory */
286 for (i = idx; i < end; i++) {
287 GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
289 gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
290 gst_memory_unref (old);
294 /* replace with single memory */
295 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
296 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
302 memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
303 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
305 GST_BUFFER_MEM_LEN (buffer) = len - length;
306 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
309 /* transfer full for return and transfer none for @mem */
310 static inline GstMemory *
311 _memory_get_exclusive_reference (GstMemory * mem)
313 GstMemory *ret = NULL;
315 if (gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE)) {
316 ret = gst_memory_ref (mem);
318 /* we cannot take another exclusive lock as the memory is already
319 * locked WRITE + EXCLUSIVE according to part-miniobject.txt */
320 ret = gst_memory_copy (mem, 0, -1);
323 if (!gst_memory_lock (ret, GST_LOCK_FLAG_EXCLUSIVE)) {
324 gst_memory_unref (ret);
331 GST_CAT_WARNING (GST_CAT_BUFFER, "Failed to acquire an exclusive lock for "
338 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem)
340 guint i, len = GST_BUFFER_MEM_LEN (buffer);
342 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p", buffer, idx, mem);
344 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
345 /* too many buffer, span them. */
346 /* FIXME, there is room for improvement here: We could only try to merge
347 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
348 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
349 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
351 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
352 /* we now have 1 single spanned buffer */
359 for (i = len; i > idx; i--) {
360 /* move buffers to insert, FIXME, we need to insert first and then merge */
361 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
363 /* and insert the new buffer */
364 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
365 GST_BUFFER_MEM_LEN (buffer) = len + 1;
367 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
370 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
373 _priv_gst_buffer_initialize (void)
375 _gst_buffer_type = gst_buffer_get_type ();
379 * gst_buffer_get_max_memory:
381 * Get the maximum amount of memory blocks that a buffer can hold. This is a
382 * compile time constant that can be queried with the function.
384 * When more memory blocks are added, existing memory blocks will be merged
385 * together to make room for the new block.
387 * Returns: the maximum amount of memory blocks that a buffer can hold.
392 gst_buffer_get_max_memory (void)
394 return GST_BUFFER_MEM_MAX;
398 * gst_buffer_copy_into:
399 * @dest: a destination #GstBuffer
400 * @src: a source #GstBuffer
401 * @flags: flags indicating what metadata fields should be copied.
402 * @offset: offset to copy from
403 * @size: total size to copy. If -1, all data is copied.
405 * Copies the information from @src into @dest.
407 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
408 * the memory from @src will be appended to @dest.
410 * @flags indicate which fields will be copied.
412 * Returns: %TRUE if the copying succeeded, %FALSE otherwise.
415 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
416 GstBufferCopyFlags flags, gsize offset, gsize size)
420 gboolean region = FALSE;
422 g_return_val_if_fail (dest != NULL, FALSE);
423 g_return_val_if_fail (src != NULL, FALSE);
425 /* nothing to copy if the buffers are the same */
426 if (G_UNLIKELY (dest == src))
429 g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
431 bufsize = gst_buffer_get_size (src);
432 g_return_val_if_fail (bufsize >= offset, FALSE);
436 size = bufsize - offset;
439 g_return_val_if_fail (bufsize >= offset + size, FALSE);
441 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
442 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
445 if (flags & GST_BUFFER_COPY_FLAGS) {
447 guint flags_mask = ~GST_BUFFER_FLAG_TAG_MEMORY;
449 GST_MINI_OBJECT_FLAGS (dest) =
450 (GST_MINI_OBJECT_FLAGS (src) & flags_mask) |
451 (GST_MINI_OBJECT_FLAGS (dest) & ~flags_mask);
454 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
456 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
457 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
458 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
459 if (size == bufsize) {
460 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
461 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
464 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
465 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
466 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
467 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
468 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
472 if (flags & GST_BUFFER_COPY_MEMORY) {
473 gsize skip, left, len, dest_len, i, bsize;
476 deep = flags & GST_BUFFER_COPY_DEEP;
478 len = GST_BUFFER_MEM_LEN (src);
479 dest_len = GST_BUFFER_MEM_LEN (dest);
483 /* copy and make regions of the memory */
484 for (i = 0; i < len && left > 0; i++) {
485 GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
487 bsize = gst_memory_get_sizes (mem, NULL, NULL);
490 /* don't copy buffer */
493 GstMemory *newmem = NULL;
496 tocopy = MIN (bsize - skip, left);
498 if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
499 /* we need to clip something */
500 newmem = gst_memory_share (mem, skip, tocopy);
502 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
507 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
508 /* deep copy or we're not allowed to share this memory
509 * between buffers, always copy then */
510 newmem = gst_memory_copy (mem, skip, tocopy);
512 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
515 } else if (!newmem) {
516 newmem = _memory_get_exclusive_reference (mem);
520 gst_buffer_remove_memory_range (dest, dest_len, -1);
524 _memory_add (dest, -1, newmem);
528 if (flags & GST_BUFFER_COPY_MERGE) {
531 len = GST_BUFFER_MEM_LEN (dest);
532 mem = _get_merged_memory (dest, 0, len);
534 gst_buffer_remove_memory_range (dest, dest_len, -1);
537 _replace_memory (dest, len, 0, len, mem);
541 if (flags & GST_BUFFER_COPY_META) {
542 /* NOTE: GstGLSyncMeta copying relies on the meta
543 * being copied now, after the buffer data,
544 * so this has to happen last */
545 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
546 GstMeta *meta = &walk->meta;
547 const GstMetaInfo *info = meta->info;
549 /* Don't copy memory metas if we only copied part of the buffer, didn't
550 * copy memories or merged memories. In all these cases the memory
551 * structure has changed and the memory meta becomes meaningless.
553 if ((region || !(flags & GST_BUFFER_COPY_MEMORY)
554 || (flags & GST_BUFFER_COPY_MERGE))
555 && gst_meta_api_type_has_tag (info->api, _gst_meta_tag_memory)) {
556 GST_CAT_DEBUG (GST_CAT_BUFFER,
557 "don't copy memory meta %p of API type %s", meta,
558 g_type_name (info->api));
559 } else if (info->transform_func) {
560 GstMetaTransformCopy copy_data;
562 copy_data.region = region;
563 copy_data.offset = offset;
564 copy_data.size = size;
566 if (!info->transform_func (dest, meta, src,
567 _gst_meta_transform_copy, ©_data)) {
568 GST_CAT_ERROR (GST_CAT_BUFFER,
569 "failed to copy meta %p of API type %s", meta,
570 g_type_name (info->api));
580 gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
584 g_return_val_if_fail (buffer != NULL, NULL);
586 /* create a fresh new buffer */
587 copy = gst_buffer_new ();
589 /* copy what the 'flags' want from our parent */
590 /* FIXME why we can't pass const to gst_buffer_copy_into() ? */
591 if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
592 gst_buffer_replace (©, NULL);
595 GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
601 _gst_buffer_copy (const GstBuffer * buffer)
603 return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
607 * gst_buffer_copy_deep:
608 * @buf: a #GstBuffer.
610 * Create a copy of the given buffer. This will make a newly allocated
611 * copy of the data the source buffer contains.
613 * Returns: (transfer full): a new copy of @buf.
618 gst_buffer_copy_deep (const GstBuffer * buffer)
620 return gst_buffer_copy_with_flags (buffer,
621 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
624 /* the default dispose function revives the buffer and returns it to the
625 * pool when there is a pool */
627 _gst_buffer_dispose (GstBuffer * buffer)
631 /* no pool, do free */
632 if ((pool = buffer->pool) == NULL)
635 /* keep the buffer alive */
636 gst_buffer_ref (buffer);
637 /* return the buffer to the pool */
638 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
639 gst_buffer_pool_release_buffer (pool, buffer);
645 _gst_buffer_free (GstBuffer * buffer)
647 GstMetaItem *walk, *next;
651 g_return_if_fail (buffer != NULL);
653 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
656 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
657 GstMeta *meta = &walk->meta;
658 const GstMetaInfo *info = meta->info;
660 /* call free_func if any */
662 info->free_func (meta, buffer);
665 /* and free the slice */
666 g_slice_free1 (ITEM_SIZE (info), walk);
669 /* get the size, when unreffing the memory, we could also unref the buffer
671 msize = GST_BUFFER_SLICE_SIZE (buffer);
673 /* free our memory */
674 len = GST_BUFFER_MEM_LEN (buffer);
675 for (i = 0; i < len; i++) {
676 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
677 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
680 /* we set msize to 0 when the buffer is part of the memory block */
683 memset (buffer, 0xff, msize);
685 g_slice_free1 (msize, buffer);
687 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
692 gst_buffer_init (GstBufferImpl * buffer, gsize size)
694 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
695 (GstMiniObjectCopyFunction) _gst_buffer_copy,
696 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
697 (GstMiniObjectFreeFunction) _gst_buffer_free);
699 GST_BUFFER_SLICE_SIZE (buffer) = size;
701 GST_BUFFER (buffer)->pool = NULL;
702 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
703 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
704 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
705 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
706 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
708 GST_BUFFER_MEM_LEN (buffer) = 0;
709 GST_BUFFER_META (buffer) = NULL;
715 * Creates a newly allocated buffer without any data.
719 * Returns: (transfer full): the new #GstBuffer.
722 gst_buffer_new (void)
724 GstBufferImpl *newbuf;
726 newbuf = g_slice_new (GstBufferImpl);
727 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
729 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
731 return GST_BUFFER_CAST (newbuf);
735 * gst_buffer_new_allocate:
736 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
738 * @size: the size in bytes of the new buffer's data.
739 * @params: (transfer none) (allow-none): optional parameters
741 * Tries to create a newly allocated buffer with data of the given size and
742 * extra parameters from @allocator. If the requested amount of memory can't be
743 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
745 * When @allocator is %NULL, the default memory allocator will be used.
747 * Note that when @size == 0, the buffer will not have memory associated with it.
751 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
752 * the memory couldn't be allocated.
755 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
756 GstAllocationParams * params)
767 mem = gst_allocator_alloc (allocator, size, params);
768 if (G_UNLIKELY (mem == NULL))
774 newbuf = gst_buffer_new ();
777 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
778 _memory_add (newbuf, -1, mem);
781 GST_CAT_LOG (GST_CAT_BUFFER,
782 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
787 asize = sizeof (GstBufferImpl) + size;
788 data = g_slice_alloc (asize);
789 if (G_UNLIKELY (data == NULL))
792 newbuf = GST_BUFFER_CAST (data);
794 gst_buffer_init ((GstBufferImpl *) data, asize);
796 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
798 _memory_add (newbuf, -1, mem, TRUE);
803 /* allocate memory and buffer, it might be interesting to do this but there
804 * are many complications. We need to keep the memory mapped to access the
805 * buffer fields and the memory for the buffer might be just very slow. We
806 * also need to do some more magic to get the alignment right. */
807 asize = sizeof (GstBufferImpl) + size;
808 mem = gst_allocator_alloc (allocator, asize, align);
809 if (G_UNLIKELY (mem == NULL))
812 /* map the data part and init the buffer in it, set the buffer size to 0 so
813 * that a finalize won't free the buffer */
814 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
815 gst_buffer_init ((GstBufferImpl *) data, 0);
816 gst_memory_unmap (mem);
818 /* strip off the buffer */
819 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
821 newbuf = GST_BUFFER_CAST (data);
822 GST_BUFFER_BUFMEM (newbuf) = mem;
825 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
827 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
834 GST_CAT_WARNING (GST_CAT_BUFFER,
835 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
841 * gst_buffer_new_wrapped_full:
842 * @flags: #GstMemoryFlags
843 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
844 * @maxsize: allocated size of @data
845 * @offset: offset in @data
846 * @size: size of valid data
847 * @user_data: (allow-none): user_data
848 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
850 * Allocate a new buffer that wraps the given memory. @data must point to
851 * @maxsize of memory, the wrapped buffer will have the region from @offset and
854 * When the buffer is destroyed, @notify will be called with @user_data.
856 * The prefix/padding must be filled with 0 if @flags contains
857 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
859 * Returns: (transfer full): a new #GstBuffer
862 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
863 gsize maxsize, gsize offset, gsize size, gpointer user_data,
864 GDestroyNotify notify)
869 newbuf = gst_buffer_new ();
871 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
873 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
874 _memory_add (newbuf, -1, mem);
875 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
881 * gst_buffer_new_wrapped:
882 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
883 * @size: allocated size of @data
885 * Creates a new buffer that wraps the given @data. The memory will be freed
886 * with g_free and will be marked writable.
890 * Returns: (transfer full): a new #GstBuffer
893 gst_buffer_new_wrapped (gpointer data, gsize size)
895 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
899 * gst_buffer_n_memory:
900 * @buffer: a #GstBuffer.
902 * Get the amount of memory blocks that this buffer has. This amount is never
903 * larger than what gst_buffer_get_max_memory() returns.
905 * Returns: the number of memory blocks this buffer is made of.
908 gst_buffer_n_memory (GstBuffer * buffer)
910 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
912 return GST_BUFFER_MEM_LEN (buffer);
916 * gst_buffer_prepend_memory:
917 * @buffer: a #GstBuffer.
918 * @mem: (transfer full): a #GstMemory.
920 * Prepend the memory block @mem to @buffer. This function takes
921 * ownership of @mem and thus doesn't increase its refcount.
923 * This function is identical to gst_buffer_insert_memory() with an index of 0.
924 * See gst_buffer_insert_memory() for more details.
927 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
929 gst_buffer_insert_memory (buffer, 0, mem);
933 * gst_buffer_append_memory:
934 * @buffer: a #GstBuffer.
935 * @mem: (transfer full): a #GstMemory.
937 * Append the memory block @mem to @buffer. This function takes
938 * ownership of @mem and thus doesn't increase its refcount.
940 * This function is identical to gst_buffer_insert_memory() with an index of -1.
941 * See gst_buffer_insert_memory() for more details.
944 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
946 gst_buffer_insert_memory (buffer, -1, mem);
950 * gst_buffer_insert_memory:
951 * @buffer: a #GstBuffer.
952 * @idx: the index to add the memory at, or -1 to append it to the end
953 * @mem: (transfer full): a #GstMemory.
955 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
956 * of @mem and thus doesn't increase its refcount.
958 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
959 * added, existing memory blocks will automatically be merged to make room for
963 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
967 g_return_if_fail (GST_IS_BUFFER (buffer));
968 g_return_if_fail (gst_buffer_is_writable (buffer));
969 g_return_if_fail (mem != NULL);
970 g_return_if_fail (idx == -1 ||
971 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
973 tmp = _memory_get_exclusive_reference (mem);
974 g_return_if_fail (tmp != NULL);
975 gst_memory_unref (mem);
976 _memory_add (buffer, idx, tmp);
980 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
983 GstMemory *mem, *mapped;
985 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
987 mapped = gst_memory_make_mapped (mem, info, flags);
990 /* memory changed, lock new memory */
991 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
992 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
993 /* unlock old memory */
994 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
995 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
997 gst_memory_unref (mem);
1003 * gst_buffer_peek_memory:
1004 * @buffer: a #GstBuffer.
1007 * Get the memory block at @idx in @buffer. The memory block stays valid until
1008 * the memory block in @buffer is removed, replaced or merged, typically with
1009 * any call that modifies the memory in @buffer.
1011 * Returns: (transfer none): the #GstMemory at @idx.
1014 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
1018 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1019 len = GST_BUFFER_MEM_LEN (buffer);
1020 g_return_val_if_fail (idx < len, NULL);
1022 return GST_BUFFER_MEM_PTR (buffer, idx);
1026 * gst_buffer_get_memory:
1027 * @buffer: a #GstBuffer.
1030 * Get the memory block at index @idx in @buffer.
1032 * Returns: (transfer full): a #GstMemory that contains the data of the
1033 * memory block at @idx. Use gst_memory_unref () after usage.
1036 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
1038 return gst_buffer_get_memory_range (buffer, idx, 1);
1042 * gst_buffer_get_all_memory:
1043 * @buffer: a #GstBuffer.
1045 * Get all the memory block in @buffer. The memory blocks will be merged
1046 * into one large #GstMemory.
1048 * Returns: (transfer full): a #GstMemory that contains the merged memory.
1049 * Use gst_memory_unref () after usage.
1052 gst_buffer_get_all_memory (GstBuffer * buffer)
1054 return gst_buffer_get_memory_range (buffer, 0, -1);
1058 * gst_buffer_get_memory_range:
1059 * @buffer: a #GstBuffer.
1063 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
1064 * be merged into one large #GstMemory.
1066 * If @length is -1, all memory starting from @idx is merged.
1068 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
1069 * blocks starting at @idx. Use gst_memory_unref () after usage.
1072 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1076 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1078 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1079 len = GST_BUFFER_MEM_LEN (buffer);
1080 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1081 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1086 return _get_merged_memory (buffer, idx, length);
1090 * gst_buffer_replace_memory:
1091 * @buffer: a #GstBuffer.
1093 * @mem: (transfer full): a #GstMemory
1095 * Replaces the memory block at index @idx in @buffer with @mem.
1098 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1100 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1104 * gst_buffer_replace_all_memory:
1105 * @buffer: a #GstBuffer.
1106 * @mem: (transfer full): a #GstMemory
1108 * Replaces all memory in @buffer with @mem.
1111 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1113 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1117 * gst_buffer_replace_memory_range:
1118 * @buffer: a #GstBuffer.
1120 * @length: a length should not be 0
1121 * @mem: (transfer full): a #GstMemory
1123 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1125 * If @length is -1, all memory starting from @idx will be removed and
1126 * replaced with @mem.
1128 * @buffer should be writable.
1131 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1136 g_return_if_fail (GST_IS_BUFFER (buffer));
1137 g_return_if_fail (gst_buffer_is_writable (buffer));
1139 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1141 len = GST_BUFFER_MEM_LEN (buffer);
1142 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1143 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1148 _replace_memory (buffer, len, idx, length, mem);
1152 * gst_buffer_remove_memory:
1153 * @buffer: a #GstBuffer.
1156 * Remove the memory block in @b at index @i.
1159 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1161 gst_buffer_remove_memory_range (buffer, idx, 1);
1165 * gst_buffer_remove_all_memory:
1166 * @buffer: a #GstBuffer.
1168 * Remove all the memory blocks in @buffer.
1171 gst_buffer_remove_all_memory (GstBuffer * buffer)
1173 gst_buffer_remove_memory_range (buffer, 0, -1);
1177 * gst_buffer_remove_memory_range:
1178 * @buffer: a #GstBuffer.
1182 * Remove @length memory blocks in @buffer starting from @idx.
1184 * @length can be -1, in which case all memory starting from @idx is removed.
1187 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1191 g_return_if_fail (GST_IS_BUFFER (buffer));
1192 g_return_if_fail (gst_buffer_is_writable (buffer));
1194 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1196 len = GST_BUFFER_MEM_LEN (buffer);
1197 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1198 (length == -1 && idx < len) || length + idx <= len);
1203 _replace_memory (buffer, len, idx, length, NULL);
1207 * gst_buffer_find_memory:
1208 * @buffer: a #GstBuffer.
1209 * @offset: an offset
1211 * @idx: (out): pointer to index
1212 * @length: (out): pointer to length
1213 * @skip: (out): pointer to skip
1215 * Find the memory blocks that span @size bytes starting from @offset
1218 * When this function returns %TRUE, @idx will contain the index of the first
1219 * memory block where the byte for @offset can be found and @length contains the
1220 * number of memory blocks containing the @size remaining bytes. @skip contains
1221 * the number of bytes to skip in the memory block at @idx to get to the byte
1224 * @size can be -1 to get all the memory blocks after @idx.
1226 * Returns: %TRUE when @size bytes starting from @offset could be found in
1227 * @buffer and @idx, @length and @skip will be filled.
1230 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1231 guint * idx, guint * length, gsize * skip)
1233 guint i, len, found;
1235 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1236 g_return_val_if_fail (idx != NULL, FALSE);
1237 g_return_val_if_fail (length != NULL, FALSE);
1238 g_return_val_if_fail (skip != NULL, FALSE);
1240 len = GST_BUFFER_MEM_LEN (buffer);
1243 for (i = 0; i < len; i++) {
1247 mem = GST_BUFFER_MEM_PTR (buffer, i);
1248 s = gst_memory_get_sizes (mem, NULL, NULL);
1251 /* block before offset, or empty block, skip */
1254 /* block after offset */
1256 /* first block, remember index and offset */
1260 /* return remaining blocks */
1267 /* count the amount of found bytes */
1269 if (found >= size) {
1270 /* we have enough bytes */
1271 *length = i - *idx + 1;
1280 * gst_buffer_is_memory_range_writable:
1281 * @buffer: a #GstBuffer.
1283 * @length: a length should not be 0
1285 * Check if @length memory blocks in @buffer starting from @idx are writable.
1287 * @length can be -1 to check all the memory blocks after @idx.
1289 * Note that this function does not check if @buffer is writable, use
1290 * gst_buffer_is_writable() to check that if needed.
1292 * Returns: %TRUE if the memory range is writable
1297 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1301 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1303 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1305 len = GST_BUFFER_MEM_LEN (buffer);
1306 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1307 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1315 for (i = 0; i < len; i++) {
1316 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1323 * gst_buffer_is_all_memory_writable:
1324 * @buffer: a #GstBuffer.
1326 * Check if all memory blocks in @buffer are writable.
1328 * Note that this function does not check if @buffer is writable, use
1329 * gst_buffer_is_writable() to check that if needed.
1331 * Returns: %TRUE if all memory blocks in @buffer are writable
1336 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1338 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1342 * gst_buffer_get_sizes:
1343 * @buffer: a #GstBuffer.
1344 * @offset: (out) (allow-none): a pointer to the offset
1345 * @maxsize: (out) (allow-none): a pointer to the maxsize
1347 * Get the total size of the memory blocks in @b.
1349 * When not %NULL, @offset will contain the offset of the data in the
1350 * first memory block in @buffer and @maxsize will contain the sum of
1351 * the size and @offset and the amount of extra padding on the last
1352 * memory block. @offset and @maxsize can be used to resize the
1353 * buffer memory blocks with gst_buffer_resize().
1355 * Returns: total size of the memory blocks in @buffer.
1358 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1360 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1364 * gst_buffer_get_size:
1365 * @buffer: a #GstBuffer.
1367 * Get the total size of the memory blocks in @buffer.
1369 * Returns: total size of the memory blocks in @buffer.
1372 gst_buffer_get_size (GstBuffer * buffer)
1374 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1378 * gst_buffer_get_sizes_range:
1379 * @buffer: a #GstBuffer.
1382 * @offset: (out) (allow-none): a pointer to the offset
1383 * @maxsize: (out) (allow-none): a pointer to the maxsize
1385 * Get the total size of @length memory blocks stating from @idx in @buffer.
1387 * When not %NULL, @offset will contain the offset of the data in the
1388 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1389 * and @offset and the amount of extra padding on the memory block at @idx +
1391 * @offset and @maxsize can be used to resize the buffer memory blocks with
1392 * gst_buffer_resize_range().
1394 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1397 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1398 gsize * offset, gsize * maxsize)
1404 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1405 len = GST_BUFFER_MEM_LEN (buffer);
1406 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1407 (length == -1 && idx < len) || (length + idx <= len), 0);
1412 if (G_LIKELY (length == 1)) {
1414 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1415 size = gst_memory_get_sizes (mem, offset, maxsize);
1421 size = offs = extra = 0;
1422 for (i = idx; i < end; i++) {
1425 mem = GST_BUFFER_MEM_PTR (buffer, i);
1426 s = gst_memory_get_sizes (mem, &o, &ms);
1430 /* first size, take accumulated data before as the offset */
1434 /* save the amount of data after this block */
1435 extra = ms - (o + s);
1437 /* empty block, add as extra */
1444 *maxsize = offs + size + extra;
1450 * gst_buffer_resize:
1451 * @buffer: a #GstBuffer.
1452 * @offset: the offset adjustment
1453 * @size: the new size or -1 to just adjust the offset
1455 * Set the offset and total size of the memory blocks in @buffer.
1458 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1460 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1464 * gst_buffer_set_size:
1465 * @buffer: a #GstBuffer.
1466 * @size: the new size
1468 * Set the total size of the memory blocks in @buffer.
1471 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1473 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1477 * gst_buffer_resize_range:
1478 * @buffer: a #GstBuffer.
1481 * @offset: the offset adjustment
1482 * @size: the new size or -1 to just adjust the offset
1484 * Set the total size of the @length memory blocks starting at @idx in
1487 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1490 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1491 gssize offset, gssize size)
1494 gsize bsize, bufsize, bufoffs, bufmax;
1496 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1497 g_return_val_if_fail (size >= -1, FALSE);
1499 len = GST_BUFFER_MEM_LEN (buffer);
1500 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1501 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1506 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1508 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1509 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1510 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1512 /* we can't go back further than the current offset or past the end of the
1514 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1515 && bufoffs + offset <= bufmax), FALSE);
1517 g_return_val_if_fail (bufsize >= offset, FALSE);
1518 size = bufsize - offset;
1520 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1523 if (offset == 0 && size == bufsize)
1528 for (i = idx; i < end; i++) {
1532 mem = GST_BUFFER_MEM_PTR (buffer, i);
1533 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1536 /* last buffer always gets resized to the remaining size */
1539 /* shrink buffers before the offset */
1540 else if ((gssize) bsize <= offset) {
1542 noffs = offset - bsize;
1545 /* clip other buffers */
1547 left = MIN (bsize - offset, size);
1549 if (offset != 0 || left != bsize) {
1550 if (gst_memory_is_writable (mem)) {
1551 gst_memory_resize (mem, offset, left);
1553 GstMemory *newmem = NULL;
1555 if (!GST_MEMORY_IS_NO_SHARE (mem))
1556 newmem = gst_memory_share (mem, offset, left);
1559 newmem = gst_memory_copy (mem, offset, left);
1564 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1565 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1566 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1567 gst_memory_unref (mem);
1569 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1582 * @buffer: a #GstBuffer.
1583 * @info: (out): info about the mapping
1584 * @flags: flags for the mapping
1586 * This function fills @info with the #GstMapInfo of all merged memory
1587 * blocks in @buffer.
1589 * @flags describe the desired access of the memory. When @flags is
1590 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1591 * gst_buffer_is_writable()).
1593 * When @buffer is writable but the memory isn't, a writable copy will
1594 * automatically be created and returned. The readonly copy of the
1595 * buffer memory will then also be replaced with this writable copy.
1597 * The memory in @info should be unmapped with gst_buffer_unmap() after
1600 * Returns: %TRUE if the map succeeded and @info contains valid data.
1603 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1605 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1609 * gst_buffer_map_range:
1610 * @buffer: a #GstBuffer.
1613 * @info: (out): info about the mapping
1614 * @flags: flags for the mapping
1616 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1617 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1618 * from @idx are merged and mapped.
1620 * @flags describe the desired access of the memory. When @flags is
1621 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1622 * gst_buffer_is_writable()).
1624 * When @buffer is writable but the memory isn't, a writable copy will
1625 * automatically be created and returned. The readonly copy of the buffer memory
1626 * will then also be replaced with this writable copy.
1628 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1630 * Returns: %TRUE if the map succeeded and @info contains valid
1634 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1635 GstMapInfo * info, GstMapFlags flags)
1637 GstMemory *mem, *nmem;
1638 gboolean write, writable;
1641 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1642 g_return_val_if_fail (info != NULL, FALSE);
1643 len = GST_BUFFER_MEM_LEN (buffer);
1644 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1645 (length == -1 && idx < len) || (length > 0
1646 && length + idx <= len), FALSE);
1648 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1649 buffer, idx, length, flags);
1651 write = (flags & GST_MAP_WRITE) != 0;
1652 writable = gst_buffer_is_writable (buffer);
1654 /* check if we can write when asked for write access */
1655 if (G_UNLIKELY (write && !writable))
1661 mem = _get_merged_memory (buffer, idx, length);
1662 if (G_UNLIKELY (mem == NULL))
1665 /* now try to map */
1666 nmem = gst_memory_make_mapped (mem, info, flags);
1667 if (G_UNLIKELY (nmem == NULL))
1670 /* if we merged or when the map returned a different memory, we try to replace
1671 * the memory in the buffer */
1672 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1673 /* if the buffer is writable, replace the memory */
1675 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1678 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1679 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1688 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1689 g_critical ("write map requested on non-writable buffer");
1690 memset (info, 0, sizeof (GstMapInfo));
1695 /* empty buffer, we need to return NULL */
1696 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1697 memset (info, 0, sizeof (GstMapInfo));
1702 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1703 memset (info, 0, sizeof (GstMapInfo));
1710 * @buffer: a #GstBuffer.
1711 * @info: a #GstMapInfo
1713 * Release the memory previously mapped with gst_buffer_map().
1716 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1718 g_return_if_fail (GST_IS_BUFFER (buffer));
1719 g_return_if_fail (info != NULL);
1721 /* we need to check for NULL, it is possible that we tried to map a buffer
1722 * without memory and we should be able to unmap that fine */
1723 if (G_LIKELY (info->memory)) {
1724 gst_memory_unmap (info->memory, info);
1725 gst_memory_unref (info->memory);
1731 * @buffer: a #GstBuffer.
1732 * @offset: the offset to fill
1733 * @src: (array length=size) (element-type guint8): the source address
1734 * @size: the size to fill
1736 * Copy @size bytes from @src to @buffer at @offset.
1738 * Returns: The amount of bytes copied. This value can be lower than @size
1739 * when @buffer did not contain enough data.
1742 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1746 const guint8 *ptr = src;
1748 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1749 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1750 g_return_val_if_fail (src != NULL || size == 0, 0);
1752 GST_CAT_LOG (GST_CAT_BUFFER,
1753 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1756 len = GST_BUFFER_MEM_LEN (buffer);
1759 for (i = 0; i < len && left > 0; i++) {
1764 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1765 if (info.size > offset) {
1766 /* we have enough */
1767 tocopy = MIN (info.size - offset, left);
1768 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1773 /* offset past buffer, skip */
1774 offset -= info.size;
1776 gst_memory_unmap (mem, &info);
1782 * gst_buffer_extract:
1783 * @buffer: a #GstBuffer.
1784 * @offset: the offset to extract
1785 * @dest: the destination address
1786 * @size: the size to extract
1788 * Copy @size bytes starting from @offset in @buffer to @dest.
1790 * Returns: The amount of bytes extracted. This value can be lower than @size
1791 * when @buffer did not contain enough data.
1794 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1799 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1800 g_return_val_if_fail (dest != NULL, 0);
1802 GST_CAT_LOG (GST_CAT_BUFFER,
1803 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1806 len = GST_BUFFER_MEM_LEN (buffer);
1809 for (i = 0; i < len && left > 0; i++) {
1814 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1815 if (info.size > offset) {
1816 /* we have enough */
1817 tocopy = MIN (info.size - offset, left);
1818 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1823 /* offset past buffer, skip */
1824 offset -= info.size;
1826 gst_memory_unmap (mem, &info);
1832 * gst_buffer_memcmp:
1833 * @buffer: a #GstBuffer.
1834 * @offset: the offset in @buffer
1835 * @mem: (array length=size) (element-type guint8): the memory to compare
1836 * @size: the size to compare
1838 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1840 * Returns: 0 if the memory is equal.
1843 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1847 const guint8 *ptr = mem;
1850 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1851 g_return_val_if_fail (mem != NULL, 0);
1853 GST_CAT_LOG (GST_CAT_BUFFER,
1854 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1857 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1860 len = GST_BUFFER_MEM_LEN (buffer);
1862 for (i = 0; i < len && size > 0 && res == 0; i++) {
1867 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1868 if (info.size > offset) {
1869 /* we have enough */
1870 tocmp = MIN (info.size - offset, size);
1871 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1876 /* offset past buffer, skip */
1877 offset -= info.size;
1879 gst_memory_unmap (mem, &info);
1885 * gst_buffer_memset:
1886 * @buffer: a #GstBuffer.
1887 * @offset: the offset in @buffer
1888 * @val: the value to set
1889 * @size: the size to set
1891 * Fill @buf with @size bytes with @val starting from @offset.
1893 * Returns: The amount of bytes filled. This value can be lower than @size
1894 * when @buffer did not contain enough data.
1897 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1901 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1902 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1904 GST_CAT_LOG (GST_CAT_BUFFER,
1905 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1906 buffer, offset, val, size);
1908 len = GST_BUFFER_MEM_LEN (buffer);
1911 for (i = 0; i < len && left > 0; i++) {
1916 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1917 if (info.size > offset) {
1918 /* we have enough */
1919 toset = MIN (info.size - offset, left);
1920 memset ((guint8 *) info.data + offset, val, toset);
1924 /* offset past buffer, skip */
1925 offset -= info.size;
1927 gst_memory_unmap (mem, &info);
1933 * gst_buffer_copy_region:
1934 * @parent: a #GstBuffer.
1935 * @flags: the #GstBufferCopyFlags
1936 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1938 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
1941 * Creates a sub-buffer from @parent at @offset and @size.
1942 * This sub-buffer uses the actual memory space of the parent buffer.
1943 * This function will copy the offset and timestamp fields when the
1944 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1945 * #GST_BUFFER_OFFSET_NONE.
1946 * If @offset equals 0 and @size equals the total size of @buffer, the
1947 * duration and offset end fields are also copied. If not they will be set
1948 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1952 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
1956 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1957 gsize offset, gsize size)
1961 g_return_val_if_fail (buffer != NULL, NULL);
1963 /* create the new buffer */
1964 copy = gst_buffer_new ();
1966 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1967 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1969 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1970 gst_buffer_replace (©, NULL);
1976 * gst_buffer_append:
1977 * @buf1: (transfer full): the first source #GstBuffer to append.
1978 * @buf2: (transfer full): the second source #GstBuffer to append.
1980 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1981 * concatenation of the memory of @buf1 and @buf2.
1983 * Returns: (transfer full): the new #GstBuffer that contains the memory
1984 * of the two source buffers.
1987 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1989 return gst_buffer_append_region (buf1, buf2, 0, -1);
1993 * gst_buffer_append_region:
1994 * @buf1: (transfer full): the first source #GstBuffer to append.
1995 * @buf2: (transfer full): the second source #GstBuffer to append.
1996 * @offset: the offset in @buf2
1997 * @size: the size or -1 of @buf2
1999 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
2000 * contain a concatenation of the memory of @buf1 and the requested region of
2003 * Returns: (transfer full): the new #GstBuffer that contains the memory
2004 * of the two source buffers.
2007 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
2012 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
2013 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
2015 buf1 = gst_buffer_make_writable (buf1);
2016 buf2 = gst_buffer_make_writable (buf2);
2018 gst_buffer_resize (buf2, offset, size);
2020 len = GST_BUFFER_MEM_LEN (buf2);
2021 for (i = 0; i < len; i++) {
2024 mem = GST_BUFFER_MEM_PTR (buf2, i);
2025 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
2026 _memory_add (buf1, -1, mem);
2029 GST_BUFFER_MEM_LEN (buf2) = 0;
2030 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
2031 gst_buffer_unref (buf2);
2037 * gst_buffer_get_meta:
2038 * @buffer: a #GstBuffer
2039 * @api: the #GType of an API
2041 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
2042 * returned. If multiple metadata with the given @api are attached to this
2043 * buffer only the first one is returned. To handle multiple metadata with a
2044 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
2045 * and check the meta->info.api member for the API type.
2047 * Returns: (transfer none) (nullable): the metadata for @api on
2051 gst_buffer_get_meta (GstBuffer * buffer, GType api)
2054 GstMeta *result = NULL;
2056 g_return_val_if_fail (buffer != NULL, NULL);
2057 g_return_val_if_fail (api != 0, NULL);
2059 /* find GstMeta of the requested API */
2060 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
2061 GstMeta *meta = &item->meta;
2062 if (meta->info->api == api) {
2071 * gst_buffer_add_meta:
2072 * @buffer: a #GstBuffer
2073 * @info: a #GstMetaInfo
2074 * @params: params for @info
2076 * Add metadata for @info to @buffer using the parameters in @params.
2078 * Returns: (transfer none): the metadata for the api in @info on @buffer.
2081 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2085 GstMeta *result = NULL;
2088 g_return_val_if_fail (buffer != NULL, NULL);
2089 g_return_val_if_fail (info != NULL, NULL);
2090 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2092 /* create a new slice */
2093 size = ITEM_SIZE (info);
2094 /* We warn in gst_meta_register() about metas without
2095 * init function but let's play safe here and prevent
2096 * uninitialized memory
2098 if (!info->init_func)
2099 item = g_slice_alloc0 (size);
2101 item = g_slice_alloc (size);
2102 result = &item->meta;
2103 result->info = info;
2104 result->flags = GST_META_FLAG_NONE;
2106 GST_CAT_DEBUG (GST_CAT_BUFFER,
2107 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2108 g_type_name (info->type), info->size);
2110 /* call the init_func when needed */
2111 if (info->init_func)
2112 if (!info->init_func (result, params, buffer))
2115 /* and add to the list of metadata */
2116 item->next = GST_BUFFER_META (buffer);
2117 GST_BUFFER_META (buffer) = item;
2123 g_slice_free1 (size, item);
2129 * gst_buffer_remove_meta:
2130 * @buffer: a #GstBuffer
2133 * Remove the metadata for @meta on @buffer.
2135 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2136 * metadata was on @buffer.
2139 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2141 GstMetaItem *walk, *prev;
2143 g_return_val_if_fail (buffer != NULL, FALSE);
2144 g_return_val_if_fail (meta != NULL, FALSE);
2145 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2146 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2149 /* find the metadata and delete */
2150 prev = GST_BUFFER_META (buffer);
2151 for (walk = prev; walk; walk = walk->next) {
2152 GstMeta *m = &walk->meta;
2154 const GstMetaInfo *info = meta->info;
2156 /* remove from list */
2157 if (GST_BUFFER_META (buffer) == walk)
2158 GST_BUFFER_META (buffer) = walk->next;
2160 prev->next = walk->next;
2161 /* call free_func if any */
2162 if (info->free_func)
2163 info->free_func (m, buffer);
2165 /* and free the slice */
2166 g_slice_free1 (ITEM_SIZE (info), walk);
2171 return walk != NULL;
2175 * gst_buffer_iterate_meta:
2176 * @buffer: a #GstBuffer
2177 * @state: an opaque state pointer
2179 * Retrieve the next #GstMeta after @current. If @state points
2180 * to %NULL, the first metadata is returned.
2182 * @state will be updated with an opaque state pointer
2184 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2185 * when there are no more items.
2188 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2192 g_return_val_if_fail (buffer != NULL, NULL);
2193 g_return_val_if_fail (state != NULL, NULL);
2195 meta = (GstMetaItem **) state;
2197 /* state NULL, move to first item */
2198 *meta = GST_BUFFER_META (buffer);
2200 /* state !NULL, move to next item in list */
2201 *meta = (*meta)->next;
2204 return &(*meta)->meta;
2210 * gst_buffer_foreach_meta:
2211 * @buffer: a #GstBuffer
2212 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2213 * @user_data: (closure): user data passed to @func
2215 * Call @func with @user_data for each meta in @buffer.
2217 * @func can modify the passed meta pointer or its contents. The return value
2218 * of @func define if this function returns or if the remaining metadata items
2219 * in the buffer should be skipped.
2221 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2224 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2227 GstMetaItem *walk, *prev, *next;
2228 gboolean res = TRUE;
2230 g_return_val_if_fail (buffer != NULL, FALSE);
2231 g_return_val_if_fail (func != NULL, FALSE);
2233 /* find the metadata and delete */
2234 prev = GST_BUFFER_META (buffer);
2235 for (walk = prev; walk; walk = next) {
2238 m = new = &walk->meta;
2241 res = func (buffer, &new, user_data);
2244 const GstMetaInfo *info = m->info;
2246 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2247 g_type_name (info->type));
2249 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2250 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2253 /* remove from list */
2254 if (GST_BUFFER_META (buffer) == walk)
2255 GST_BUFFER_META (buffer) = next;
2259 /* call free_func if any */
2260 if (info->free_func)
2261 info->free_func (m, buffer);
2263 /* and free the slice */
2264 g_slice_free1 (ITEM_SIZE (info), walk);
2273 * gst_buffer_extract_dup:
2274 * @buffer: a #GstBuffer
2275 * @offset: the offset to extract
2276 * @size: the size to extract
2277 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2278 * the destination array will be written.
2279 * @dest_size: (out): A location where the size of @dest can be written
2281 * Extracts a copy of at most @size bytes the data at @offset into
2282 * newly-allocated memory. @dest must be freed using g_free() when done.
2288 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2289 gpointer * dest, gsize * dest_size)
2293 real_size = gst_buffer_get_size (buffer);
2295 *dest = g_malloc (MIN (real_size - offset, size));
2297 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);
2300 GST_DEBUG_CATEGORY_STATIC (gst_parent_buffer_meta_debug);
2303 * gst_buffer_add_parent_buffer_meta:
2304 * @buffer: (transfer none): a #GstBuffer
2305 * @ref: (transfer none): a #GstBuffer to ref
2307 * Add a #GstParentBufferMeta to @buffer that holds a reference on
2308 * @ref until the buffer is freed.
2310 * Returns: (transfer none): The #GstParentBufferMeta that was added to the buffer
2314 GstParentBufferMeta *
2315 gst_buffer_add_parent_buffer_meta (GstBuffer * buffer, GstBuffer * ref)
2317 GstParentBufferMeta *meta;
2319 g_return_val_if_fail (GST_IS_BUFFER (ref), NULL);
2322 (GstParentBufferMeta *) gst_buffer_add_meta (buffer,
2323 GST_PARENT_BUFFER_META_INFO, NULL);
2328 meta->buffer = gst_buffer_ref (ref);
2334 _gst_parent_buffer_meta_transform (GstBuffer * dest, GstMeta * meta,
2335 GstBuffer * buffer, GQuark type, gpointer data)
2337 GstParentBufferMeta *dmeta, *smeta;
2339 smeta = (GstParentBufferMeta *) meta;
2341 if (GST_META_TRANSFORM_IS_COPY (type)) {
2342 /* copy over the reference to the parent buffer.
2343 * Usually, this meta means we need to keep the parent buffer
2344 * alive because one of the child memories is in use, which
2345 * might not be the case if memory is deep copied or sub-regioned,
2346 * but we can't tell, so keep the meta */
2347 dmeta = gst_buffer_add_parent_buffer_meta (dest, smeta->buffer);
2351 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2352 "copy buffer reference metadata");
2354 /* return FALSE, if transform type is not supported */
2361 _gst_parent_buffer_meta_free (GstParentBufferMeta * parent_meta,
2364 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2365 "Dropping reference on buffer %p", parent_meta->buffer);
2366 gst_buffer_unref (parent_meta->buffer);
2370 _gst_parent_buffer_meta_init (GstParentBufferMeta * parent_meta,
2371 gpointer params, GstBuffer * buffer)
2373 static volatile gsize _init;
2375 if (g_once_init_enter (&_init)) {
2376 GST_DEBUG_CATEGORY_INIT (gst_parent_buffer_meta_debug, "parentbuffermeta",
2377 0, "parentbuffermeta");
2378 g_once_init_leave (&_init, 1);
2381 parent_meta->buffer = NULL;
2387 gst_parent_buffer_meta_api_get_type (void)
2389 static volatile GType type = 0;
2390 static const gchar *tags[] = { NULL };
2392 if (g_once_init_enter (&type)) {
2393 GType _type = gst_meta_api_type_register ("GstParentBufferMetaAPI", tags);
2394 g_once_init_leave (&type, _type);
2401 * gst_parent_buffer_meta_get_info:
2403 * Get the global #GstMetaInfo describing the #GstParentBufferMeta meta.
2405 * Returns: (transfer none): The #GstMetaInfo
2410 gst_parent_buffer_meta_get_info (void)
2412 static const GstMetaInfo *meta_info = NULL;
2414 if (g_once_init_enter (&meta_info)) {
2415 const GstMetaInfo *meta =
2416 gst_meta_register (gst_parent_buffer_meta_api_get_type (),
2417 "GstParentBufferMeta",
2418 sizeof (GstParentBufferMeta),
2419 (GstMetaInitFunction) _gst_parent_buffer_meta_init,
2420 (GstMetaFreeFunction) _gst_parent_buffer_meta_free,
2421 _gst_parent_buffer_meta_transform);
2422 g_once_init_leave (&meta_info, meta);