2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstbuffer.c: Buffer operations
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
25 * @short_description: Data-passing buffer type
26 * @see_also: #GstPad, #GstMiniObject, #GstMemory, #GstMeta, #GstBufferPool
28 * Buffers are the basic unit of data transfer in GStreamer. They contain the
29 * timing and offset along with other arbitrary metadata that is associated
30 * with the #GstMemory blocks that the buffer contains.
32 * Buffers are usually created with gst_buffer_new(). After a buffer has been
33 * created one will typically allocate memory for it and add it to the buffer.
34 * The following example creates a buffer that can hold a given video frame
35 * with a given width, height and bits per plane.
39 * gint size, width, height, bpp;
41 * size = width * height * bpp;
42 * buffer = gst_buffer_new ();
43 * memory = gst_allocator_alloc (NULL, size, NULL);
44 * gst_buffer_insert_memory (buffer, -1, memory);
48 * Alternatively, use gst_buffer_new_allocate() to create a buffer with
49 * preallocated data of a given size.
51 * Buffers can contain a list of #GstMemory objects. You can retrieve how many
52 * memory objects with gst_buffer_n_memory() and you can get a pointer
53 * to memory with gst_buffer_peek_memory()
55 * A buffer will usually have timestamps, and a duration, but neither of these
56 * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
57 * meaningful value can be given for these, they should be set. The timestamps
58 * and duration are measured in nanoseconds (they are #GstClockTime values).
60 * The buffer DTS refers to the timestamp when the buffer should be decoded and
61 * is usually monotonically increasing. The buffer PTS refers to the timestamp when
62 * the buffer content should be presented to the user and is not always
63 * monotonically increasing.
65 * A buffer can also have one or both of a start and an end offset. These are
66 * media-type specific. For video buffers, the start offset will generally be
67 * the frame number. For audio buffers, it will be the number of samples
68 * produced so far. For compressed data, it could be the byte offset in a
69 * source or destination file. Likewise, the end offset will be the offset of
70 * the end of the buffer. These can only be meaningfully interpreted if you
71 * know the media type of the buffer (the preceding CAPS event). Either or both
72 * can be set to #GST_BUFFER_OFFSET_NONE.
74 * gst_buffer_ref() is used to increase the refcount of a buffer. This must be
75 * done when you want to keep a handle to the buffer after pushing it to the
76 * next element. The buffer refcount determines the writability of the buffer, a
77 * buffer is only writable when the refcount is exactly 1, i.e. when the caller
78 * has the only reference to the buffer.
80 * To efficiently create a smaller buffer out of an existing one, you can
81 * use gst_buffer_copy_region(). This method tries to share the memory objects
82 * between the two buffers.
84 * If a plug-in wants to modify the buffer data or metadata in-place, it should
85 * first obtain a buffer that is safe to modify by using
86 * gst_buffer_make_writable(). This function is optimized so that a copy will
87 * only be made when it is necessary.
89 * Several flags of the buffer can be set and unset with the
90 * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
91 * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlags flag is set.
93 * Buffers can be efficiently merged into a larger buffer with
94 * gst_buffer_append(). Copying of memory will only be done when absolutely
97 * Arbitrary extra metadata can be set on a buffer with gst_buffer_add_meta().
98 * Metadata can be retrieved with gst_buffer_get_meta(). See also #GstMeta
100 * An element should either unref the buffer or push it out on a src pad
101 * using gst_pad_push() (see #GstPad).
103 * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
104 * the refcount drops to 0, any memory and metadata pointed to by the buffer is
105 * unreffed as well. Buffers allocated from a #GstBufferPool will be returned to
106 * the pool when the refcount drops to 0.
108 #include "gst_private.h"
117 #include "gstbuffer.h"
118 #include "gstbufferpool.h"
120 #include "gstutils.h"
121 #include "gstversion.h"
123 GType _gst_buffer_type = 0;
125 typedef struct _GstMetaItem GstMetaItem;
132 #define ITEM_SIZE(info) ((info)->size + sizeof (GstMetaItem))
134 #define GST_BUFFER_MEM_MAX 16
136 #define GST_BUFFER_SLICE_SIZE(b) (((GstBufferImpl *)(b))->slice_size)
137 #define GST_BUFFER_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
138 #define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
139 #define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
140 #define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
141 #define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
149 /* the memory blocks */
151 GstMemory *mem[GST_BUFFER_MEM_MAX];
153 /* memory of the buffer when allocated from 1 chunk */
156 /* FIXME, make metadata allocation more efficient by using part of the
163 _is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
165 GstMemory *mcur, *mprv;
166 gboolean have_offset = FALSE;
171 for (i = 0; i < len; i++) {
179 /* check if memory is contiguous */
180 if (!gst_memory_is_span (mprv, mcur, &poffs))
187 *parent = mprv->parent;
197 _get_merged_memory (GstBuffer * buffer, guint idx, guint length)
199 GstMemory **mem, *result = NULL;
201 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %u", buffer, idx,
204 mem = GST_BUFFER_MEM_ARRAY (buffer);
206 if (G_UNLIKELY (length == 0)) {
208 } else if (G_LIKELY (length == 1)) {
209 result = gst_memory_ref (mem[idx]);
211 GstMemory *parent = NULL;
212 gsize size, poffset = 0;
214 size = gst_buffer_get_sizes_range (buffer, idx, length, NULL, NULL);
216 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
217 if (!GST_MEMORY_IS_NO_SHARE (parent))
218 result = gst_memory_share (parent, poffset, size);
220 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
221 result = gst_memory_copy (parent, poffset, size);
224 gsize i, tocopy, left;
225 GstMapInfo sinfo, dinfo;
228 result = gst_allocator_alloc (NULL, size, NULL);
229 gst_memory_map (result, &dinfo, GST_MAP_WRITE);
234 for (i = idx; i < (idx + length) && left > 0; i++) {
235 gst_memory_map (mem[i], &sinfo, GST_MAP_READ);
236 tocopy = MIN (sinfo.size, left);
237 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
238 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
239 tocopy, result, mem[i]);
240 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
243 gst_memory_unmap (mem[i], &sinfo);
245 gst_memory_unmap (result, &dinfo);
252 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
259 GST_CAT_LOG (GST_CAT_BUFFER,
260 "buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
263 /* unref old memory */
264 for (i = idx; i < end; i++) {
265 GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
267 gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
268 gst_memory_unref (old);
272 /* replace with single memory */
273 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
274 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
280 memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
281 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
283 GST_BUFFER_MEM_LEN (buffer) = len - length;
284 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
288 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem, gboolean lock)
290 guint i, len = GST_BUFFER_MEM_LEN (buffer);
292 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p, lock %d", buffer,
295 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
296 /* too many buffer, span them. */
297 /* FIXME, there is room for improvement here: We could only try to merge
298 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
299 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
300 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
302 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
303 /* we now have 1 single spanned buffer */
310 for (i = len; i > idx; i--) {
311 /* move buffers to insert, FIXME, we need to insert first and then merge */
312 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
314 /* and insert the new buffer */
316 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
317 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
318 GST_BUFFER_MEM_LEN (buffer) = len + 1;
320 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
323 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
326 _priv_gst_buffer_initialize (void)
328 _gst_buffer_type = gst_buffer_get_type ();
332 * gst_buffer_get_max_memory:
334 * Get the maximum amount of memory blocks that a buffer can hold. This is a
335 * compile time constant that can be queried with the function.
337 * When more memory blocks are added, existing memory blocks will be merged
338 * together to make room for the new block.
340 * Returns: the maximum amount of memory blocks that a buffer can hold.
345 gst_buffer_get_max_memory (void)
347 return GST_BUFFER_MEM_MAX;
351 * gst_buffer_copy_into:
352 * @dest: a destination #GstBuffer
353 * @src: a source #GstBuffer
354 * @flags: flags indicating what metadata fields should be copied.
355 * @offset: offset to copy from
356 * @size: total size to copy. If -1, all data is copied.
358 * Copies the information from @src into @dest.
360 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
361 * the memory from @src will be appended to @dest.
363 * @flags indicate which fields will be copied.
365 * Returns: %TRUE if the copying succeeded, %FALSE otherwise.
368 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
369 GstBufferCopyFlags flags, gsize offset, gsize size)
373 gboolean region = FALSE;
375 g_return_val_if_fail (dest != NULL, FALSE);
376 g_return_val_if_fail (src != NULL, FALSE);
378 /* nothing to copy if the buffers are the same */
379 if (G_UNLIKELY (dest == src))
382 g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
384 bufsize = gst_buffer_get_size (src);
385 g_return_val_if_fail (bufsize >= offset, FALSE);
389 size = bufsize - offset;
392 g_return_val_if_fail (bufsize >= offset + size, FALSE);
394 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
395 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
398 if (flags & GST_BUFFER_COPY_FLAGS) {
400 guint flags_mask = ~GST_BUFFER_FLAG_TAG_MEMORY;
402 GST_MINI_OBJECT_FLAGS (dest) =
403 (GST_MINI_OBJECT_FLAGS (src) & flags_mask) |
404 (GST_MINI_OBJECT_FLAGS (dest) & ~flags_mask);
407 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
409 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
410 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
411 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
412 if (size == bufsize) {
413 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
414 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
417 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
418 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
419 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
420 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
421 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
425 if (flags & GST_BUFFER_COPY_MEMORY) {
426 gsize skip, left, len, dest_len, i, bsize;
429 deep = flags & GST_BUFFER_COPY_DEEP;
431 len = GST_BUFFER_MEM_LEN (src);
432 dest_len = GST_BUFFER_MEM_LEN (dest);
436 /* copy and make regions of the memory */
437 for (i = 0; i < len && left > 0; i++) {
438 GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
440 bsize = gst_memory_get_sizes (mem, NULL, NULL);
443 /* don't copy buffer */
446 GstMemory *newmem = NULL;
449 tocopy = MIN (bsize - skip, left);
451 if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
452 /* we need to clip something */
453 newmem = gst_memory_share (mem, skip, tocopy);
458 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
459 /* deep copy or we're not allowed to share this memory
460 * between buffers, always copy then */
461 newmem = gst_memory_copy (mem, skip, tocopy);
463 } else if (!newmem) {
464 newmem = gst_memory_ref (mem);
468 gst_buffer_remove_memory_range (dest, dest_len, -1);
472 _memory_add (dest, -1, newmem, TRUE);
476 if (flags & GST_BUFFER_COPY_MERGE) {
479 len = GST_BUFFER_MEM_LEN (dest);
480 mem = _get_merged_memory (dest, 0, len);
482 gst_buffer_remove_memory_range (dest, dest_len, -1);
485 _replace_memory (dest, len, 0, len, mem);
489 if (flags & GST_BUFFER_COPY_META) {
490 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
491 GstMeta *meta = &walk->meta;
492 const GstMetaInfo *info = meta->info;
494 if (info->transform_func) {
495 GstMetaTransformCopy copy_data;
497 copy_data.region = region;
498 copy_data.offset = offset;
499 copy_data.size = size;
501 if (!info->transform_func (dest, meta, src,
502 _gst_meta_transform_copy, ©_data)) {
503 GST_CAT_ERROR (GST_CAT_BUFFER,
504 "failed to copy meta %p of API type %s", meta,
505 g_type_name (info->api));
515 gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
519 g_return_val_if_fail (buffer != NULL, NULL);
521 /* create a fresh new buffer */
522 copy = gst_buffer_new ();
524 /* copy what the 'flags' want from our parent */
525 /* FIXME why we can't pass const to gst_buffer_copy_into() ? */
526 if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
527 gst_buffer_replace (©, NULL);
530 GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
536 _gst_buffer_copy (const GstBuffer * buffer)
538 return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
542 * gst_buffer_copy_deep:
543 * @buf: a #GstBuffer.
545 * Create a copy of the given buffer. This will make a newly allocated
546 * copy of the data the source buffer contains.
548 * Returns: (transfer full): a new copy of @buf.
551 gst_buffer_copy_deep (const GstBuffer * buffer)
553 return gst_buffer_copy_with_flags (buffer,
554 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
557 /* the default dispose function revives the buffer and returns it to the
558 * pool when there is a pool */
560 _gst_buffer_dispose (GstBuffer * buffer)
564 /* no pool, do free */
565 if ((pool = buffer->pool) == NULL)
568 /* keep the buffer alive */
569 gst_buffer_ref (buffer);
570 /* return the buffer to the pool */
571 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
572 gst_buffer_pool_release_buffer (pool, buffer);
578 _gst_buffer_free (GstBuffer * buffer)
580 GstMetaItem *walk, *next;
584 g_return_if_fail (buffer != NULL);
586 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
589 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
590 GstMeta *meta = &walk->meta;
591 const GstMetaInfo *info = meta->info;
593 /* call free_func if any */
595 info->free_func (meta, buffer);
598 /* and free the slice */
599 g_slice_free1 (ITEM_SIZE (info), walk);
602 /* get the size, when unreffing the memory, we could also unref the buffer
604 msize = GST_BUFFER_SLICE_SIZE (buffer);
606 /* free our memory */
607 len = GST_BUFFER_MEM_LEN (buffer);
608 for (i = 0; i < len; i++) {
609 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
610 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
613 /* we set msize to 0 when the buffer is part of the memory block */
616 memset (buffer, 0xff, msize);
618 g_slice_free1 (msize, buffer);
620 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
625 gst_buffer_init (GstBufferImpl * buffer, gsize size)
627 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
628 (GstMiniObjectCopyFunction) _gst_buffer_copy,
629 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
630 (GstMiniObjectFreeFunction) _gst_buffer_free);
632 GST_BUFFER_SLICE_SIZE (buffer) = size;
634 GST_BUFFER (buffer)->pool = NULL;
635 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
636 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
637 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
638 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
639 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
641 GST_BUFFER_MEM_LEN (buffer) = 0;
642 GST_BUFFER_META (buffer) = NULL;
648 * Creates a newly allocated buffer without any data.
652 * Returns: (transfer full): the new #GstBuffer.
655 gst_buffer_new (void)
657 GstBufferImpl *newbuf;
659 newbuf = g_slice_new (GstBufferImpl);
660 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
662 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
664 return GST_BUFFER_CAST (newbuf);
668 * gst_buffer_new_allocate:
669 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
671 * @size: the size in bytes of the new buffer's data.
672 * @params: (transfer none) (allow-none): optional parameters
674 * Tries to create a newly allocated buffer with data of the given size and
675 * extra parameters from @allocator. If the requested amount of memory can't be
676 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
678 * When @allocator is %NULL, the default memory allocator will be used.
680 * Note that when @size == 0, the buffer will not have memory associated with it.
684 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
685 * the memory couldn't be allocated.
688 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
689 GstAllocationParams * params)
700 mem = gst_allocator_alloc (allocator, size, params);
701 if (G_UNLIKELY (mem == NULL))
707 newbuf = gst_buffer_new ();
710 _memory_add (newbuf, -1, mem, TRUE);
712 GST_CAT_LOG (GST_CAT_BUFFER,
713 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
718 asize = sizeof (GstBufferImpl) + size;
719 data = g_slice_alloc (asize);
720 if (G_UNLIKELY (data == NULL))
723 newbuf = GST_BUFFER_CAST (data);
725 gst_buffer_init ((GstBufferImpl *) data, asize);
727 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
729 _memory_add (newbuf, -1, mem, TRUE);
734 /* allocate memory and buffer, it might be interesting to do this but there
735 * are many complications. We need to keep the memory mapped to access the
736 * buffer fields and the memory for the buffer might be just very slow. We
737 * also need to do some more magic to get the alignment right. */
738 asize = sizeof (GstBufferImpl) + size;
739 mem = gst_allocator_alloc (allocator, asize, align);
740 if (G_UNLIKELY (mem == NULL))
743 /* map the data part and init the buffer in it, set the buffer size to 0 so
744 * that a finalize won't free the buffer */
745 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
746 gst_buffer_init ((GstBufferImpl *) data, 0);
747 gst_memory_unmap (mem);
749 /* strip off the buffer */
750 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
752 newbuf = GST_BUFFER_CAST (data);
753 GST_BUFFER_BUFMEM (newbuf) = mem;
756 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
758 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
765 GST_CAT_WARNING (GST_CAT_BUFFER,
766 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
772 * gst_buffer_new_wrapped_full:
773 * @flags: #GstMemoryFlags
774 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
775 * @maxsize: allocated size of @data
776 * @offset: offset in @data
777 * @size: size of valid data
778 * @user_data: (allow-none): user_data
779 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
781 * Allocate a new buffer that wraps the given memory. @data must point to
782 * @maxsize of memory, the wrapped buffer will have the region from @offset and
785 * When the buffer is destroyed, @notify will be called with @user_data.
787 * The prefix/padding must be filled with 0 if @flags contains
788 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
790 * Returns: (transfer full): a new #GstBuffer
793 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
794 gsize maxsize, gsize offset, gsize size, gpointer user_data,
795 GDestroyNotify notify)
800 newbuf = gst_buffer_new ();
802 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
804 _memory_add (newbuf, -1, mem, TRUE);
805 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
811 * gst_buffer_new_wrapped:
812 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
813 * @size: allocated size of @data
815 * Creates a new buffer that wraps the given @data. The memory will be freed
816 * with g_free and will be marked writable.
820 * Returns: (transfer full): a new #GstBuffer
823 gst_buffer_new_wrapped (gpointer data, gsize size)
825 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
829 * gst_buffer_n_memory:
830 * @buffer: a #GstBuffer.
832 * Get the amount of memory blocks that this buffer has. This amount is never
833 * larger than what gst_buffer_get_max_memory() returns.
835 * Returns: (transfer full): the amount of memory block in this buffer.
838 gst_buffer_n_memory (GstBuffer * buffer)
840 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
842 return GST_BUFFER_MEM_LEN (buffer);
846 * gst_buffer_prepend_memory:
847 * @buffer: a #GstBuffer.
848 * @mem: (transfer full): a #GstMemory.
850 * Prepend the memory block @mem to @buffer. This function takes
851 * ownership of @mem and thus doesn't increase its refcount.
853 * This function is identical to gst_buffer_insert_memory() with an index of 0.
854 * See gst_buffer_insert_memory() for more details.
857 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
859 gst_buffer_insert_memory (buffer, 0, mem);
863 * gst_buffer_append_memory:
864 * @buffer: a #GstBuffer.
865 * @mem: (transfer full): a #GstMemory.
867 * Append the memory block @mem to @buffer. This function takes
868 * ownership of @mem and thus doesn't increase its refcount.
870 * This function is identical to gst_buffer_insert_memory() with an index of -1.
871 * See gst_buffer_insert_memory() for more details.
874 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
876 gst_buffer_insert_memory (buffer, -1, mem);
880 * gst_buffer_insert_memory:
881 * @buffer: a #GstBuffer.
882 * @idx: the index to add the memory at, or -1 to append it to the end
883 * @mem: (transfer full): a #GstMemory.
885 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
886 * of @mem and thus doesn't increase its refcount.
888 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
889 * added, existing memory blocks will automatically be merged to make room for
893 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
895 g_return_if_fail (GST_IS_BUFFER (buffer));
896 g_return_if_fail (gst_buffer_is_writable (buffer));
897 g_return_if_fail (mem != NULL);
898 g_return_if_fail (idx == -1 ||
899 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
901 _memory_add (buffer, idx, mem, TRUE);
905 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
908 GstMemory *mem, *mapped;
910 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
912 mapped = gst_memory_make_mapped (mem, info, flags);
915 /* memory changed, lock new memory */
916 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
917 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
918 /* unlock old memory */
919 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
920 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
922 gst_memory_unref (mem);
928 * gst_buffer_peek_memory:
929 * @buffer: a #GstBuffer.
932 * Get the memory block at @idx in @buffer. The memory block stays valid until
933 * the memory block in @buffer is removed, replaced or merged, typically with
934 * any call that modifies the memory in @buffer.
936 * Returns: (transfer none): the #GstMemory at @idx.
939 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
943 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
944 len = GST_BUFFER_MEM_LEN (buffer);
945 g_return_val_if_fail (idx < len, NULL);
947 return GST_BUFFER_MEM_PTR (buffer, idx);
951 * gst_buffer_get_memory:
952 * @buffer: a #GstBuffer.
955 * Get the memory block at index @idx in @buffer.
957 * Returns: (transfer full): a #GstMemory that contains the data of the
958 * memory block at @idx. Use gst_memory_unref () after usage.
961 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
963 return gst_buffer_get_memory_range (buffer, idx, 1);
967 * gst_buffer_get_all_memory:
968 * @buffer: a #GstBuffer.
970 * Get all the memory block in @buffer. The memory blocks will be merged
971 * into one large #GstMemory.
973 * Returns: (transfer full): a #GstMemory that contains the merged memory.
974 * Use gst_memory_unref () after usage.
977 gst_buffer_get_all_memory (GstBuffer * buffer)
979 return gst_buffer_get_memory_range (buffer, 0, -1);
983 * gst_buffer_get_memory_range:
984 * @buffer: a #GstBuffer.
988 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
989 * be merged into one large #GstMemory.
991 * If @length is -1, all memory starting from @idx is merged.
993 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
994 * blocks starting at @idx. Use gst_memory_unref () after usage.
997 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1001 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1003 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1004 len = GST_BUFFER_MEM_LEN (buffer);
1005 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1006 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1011 return _get_merged_memory (buffer, idx, length);
1015 * gst_buffer_replace_memory:
1016 * @buffer: a #GstBuffer.
1018 * @mem: (transfer full): a #GstMemory
1020 * Replaces the memory block at index @idx in @buffer with @mem.
1023 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1025 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1029 * gst_buffer_replace_all_memory:
1030 * @buffer: a #GstBuffer.
1031 * @mem: (transfer full): a #GstMemory
1033 * Replaces all memory in @buffer with @mem.
1036 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1038 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1042 * gst_buffer_replace_memory_range:
1043 * @buffer: a #GstBuffer.
1045 * @length: a length should not be 0
1046 * @mem: (transfer full): a #GstMemory
1048 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1050 * If @length is -1, all memory starting from @idx will be removed and
1051 * replaced with @mem.
1053 * @buffer should be writable.
1056 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1061 g_return_if_fail (GST_IS_BUFFER (buffer));
1062 g_return_if_fail (gst_buffer_is_writable (buffer));
1064 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1066 len = GST_BUFFER_MEM_LEN (buffer);
1067 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1068 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1073 _replace_memory (buffer, len, idx, length, mem);
1077 * gst_buffer_remove_memory:
1078 * @buffer: a #GstBuffer.
1081 * Remove the memory block in @b at index @i.
1084 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1086 gst_buffer_remove_memory_range (buffer, idx, 1);
1090 * gst_buffer_remove_all_memory:
1091 * @buffer: a #GstBuffer.
1093 * Remove all the memory blocks in @buffer.
1096 gst_buffer_remove_all_memory (GstBuffer * buffer)
1098 gst_buffer_remove_memory_range (buffer, 0, -1);
1102 * gst_buffer_remove_memory_range:
1103 * @buffer: a #GstBuffer.
1107 * Remove @length memory blocks in @buffer starting from @idx.
1109 * @length can be -1, in which case all memory starting from @idx is removed.
1112 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1116 g_return_if_fail (GST_IS_BUFFER (buffer));
1117 g_return_if_fail (gst_buffer_is_writable (buffer));
1119 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1121 len = GST_BUFFER_MEM_LEN (buffer);
1122 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1123 (length == -1 && idx < len) || length + idx <= len);
1128 _replace_memory (buffer, len, idx, length, NULL);
1132 * gst_buffer_find_memory:
1133 * @buffer: a #GstBuffer.
1134 * @offset: an offset
1136 * @idx: (out): pointer to index
1137 * @length: (out): pointer to length
1138 * @skip: (out): pointer to skip
1140 * Find the memory blocks that span @size bytes starting from @offset
1143 * When this function returns %TRUE, @idx will contain the index of the first
1144 * memory block where the byte for @offset can be found and @length contains the
1145 * number of memory blocks containing the @size remaining bytes. @skip contains
1146 * the number of bytes to skip in the memory block at @idx to get to the byte
1149 * @size can be -1 to get all the memory blocks after @idx.
1151 * Returns: %TRUE when @size bytes starting from @offset could be found in
1152 * @buffer and @idx, @length and @skip will be filled.
1155 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1156 guint * idx, guint * length, gsize * skip)
1158 guint i, len, found;
1160 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1161 g_return_val_if_fail (idx != NULL, FALSE);
1162 g_return_val_if_fail (length != NULL, FALSE);
1163 g_return_val_if_fail (skip != NULL, FALSE);
1165 len = GST_BUFFER_MEM_LEN (buffer);
1168 for (i = 0; i < len; i++) {
1172 mem = GST_BUFFER_MEM_PTR (buffer, i);
1173 s = gst_memory_get_sizes (mem, NULL, NULL);
1176 /* block before offset, or empty block, skip */
1179 /* block after offset */
1181 /* first block, remember index and offset */
1185 /* return remaining blocks */
1192 /* count the amount of found bytes */
1194 if (found >= size) {
1195 /* we have enough bytes */
1196 *length = i - *idx + 1;
1205 * gst_buffer_is_memory_range_writable:
1206 * @buffer: a #GstBuffer.
1208 * @length: a length should not be 0
1210 * Check if @length memory blocks in @buffer starting from @idx are writable.
1212 * @length can be -1 to check all the memory blocks after @idx.
1214 * Note that this function does not check if @buffer is writable, use
1215 * gst_buffer_is_writable() to check that if needed.
1217 * Returns: %TRUE if the memory range is writable
1222 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1226 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1228 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1230 len = GST_BUFFER_MEM_LEN (buffer);
1231 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1232 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1240 for (i = 0; i < len; i++) {
1241 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1248 * gst_buffer_is_all_memory_writable:
1249 * @buffer: a #GstBuffer.
1251 * Check if all memory blocks in @buffer are writable.
1253 * Note that this function does not check if @buffer is writable, use
1254 * gst_buffer_is_writable() to check that if needed.
1256 * Returns: %TRUE if all memory blocks in @buffer are writable
1261 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1263 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1267 * gst_buffer_get_sizes:
1268 * @buffer: a #GstBuffer.
1269 * @offset: (out) (allow-none): a pointer to the offset
1270 * @maxsize: (out) (allow-none): a pointer to the maxsize
1272 * Get the total size of the memory blocks in @b.
1274 * When not %NULL, @offset will contain the offset of the data in the
1275 * first memory block in @buffer and @maxsize will contain the sum of
1276 * the size and @offset and the amount of extra padding on the last
1277 * memory block. @offset and @maxsize can be used to resize the
1278 * buffer memory blocks with gst_buffer_resize().
1280 * Returns: total size of the memory blocks in @buffer.
1283 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1285 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1289 * gst_buffer_get_size:
1290 * @buffer: a #GstBuffer.
1292 * Get the total size of the memory blocks in @buffer.
1294 * Returns: total size of the memory blocks in @buffer.
1297 gst_buffer_get_size (GstBuffer * buffer)
1299 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1303 * gst_buffer_get_sizes_range:
1304 * @buffer: a #GstBuffer.
1307 * @offset: (out) (allow-none): a pointer to the offset
1308 * @maxsize: (out) (allow-none): a pointer to the maxsize
1310 * Get the total size of @length memory blocks stating from @idx in @buffer.
1312 * When not %NULL, @offset will contain the offset of the data in the
1313 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1314 * and @offset and the amount of extra padding on the memory block at @idx +
1316 * @offset and @maxsize can be used to resize the buffer memory blocks with
1317 * gst_buffer_resize_range().
1319 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1322 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1323 gsize * offset, gsize * maxsize)
1329 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1330 len = GST_BUFFER_MEM_LEN (buffer);
1331 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1332 (length == -1 && idx < len) || (length + idx <= len), 0);
1337 if (G_LIKELY (length == 1)) {
1339 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1340 size = gst_memory_get_sizes (mem, offset, maxsize);
1346 size = offs = extra = 0;
1347 for (i = idx; i < end; i++) {
1350 mem = GST_BUFFER_MEM_PTR (buffer, i);
1351 s = gst_memory_get_sizes (mem, &o, &ms);
1355 /* first size, take accumulated data before as the offset */
1359 /* save the amount of data after this block */
1360 extra = ms - (o + s);
1362 /* empty block, add as extra */
1369 *maxsize = offs + size + extra;
1375 * gst_buffer_resize:
1376 * @buffer: a #GstBuffer.
1377 * @offset: the offset adjustment
1378 * @size: the new size or -1 to just adjust the offset
1380 * Set the offset and total size of the memory blocks in @buffer.
1383 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1385 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1389 * gst_buffer_set_size:
1390 * @buffer: a #GstBuffer.
1391 * @size: the new size
1393 * Set the total size of the memory blocks in @buffer.
1396 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1398 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1402 * gst_buffer_resize_range:
1403 * @buffer: a #GstBuffer.
1406 * @offset: the offset adjustment
1407 * @size: the new size or -1 to just adjust the offset
1409 * Set the total size of the @length memory blocks starting at @idx in
1412 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1415 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1416 gssize offset, gssize size)
1419 gsize bsize, bufsize, bufoffs, bufmax;
1421 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1422 g_return_val_if_fail (size >= -1, FALSE);
1424 len = GST_BUFFER_MEM_LEN (buffer);
1425 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1426 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1431 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1433 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1434 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1435 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1437 /* we can't go back further than the current offset or past the end of the
1439 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1440 && bufoffs + offset <= bufmax), FALSE);
1442 g_return_val_if_fail (bufsize >= offset, FALSE);
1443 size = bufsize - offset;
1445 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1448 if (offset == 0 && size == bufsize)
1453 for (i = idx; i < end; i++) {
1457 mem = GST_BUFFER_MEM_PTR (buffer, i);
1458 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1461 /* last buffer always gets resized to the remaining size */
1464 /* shrink buffers before the offset */
1465 else if ((gssize) bsize <= offset) {
1467 noffs = offset - bsize;
1470 /* clip other buffers */
1472 left = MIN (bsize - offset, size);
1474 if (offset != 0 || left != bsize) {
1475 if (gst_memory_is_writable (mem)) {
1476 gst_memory_resize (mem, offset, left);
1478 GstMemory *newmem = NULL;
1480 if (!GST_MEMORY_IS_NO_SHARE (mem))
1481 newmem = gst_memory_share (mem, offset, left);
1484 newmem = gst_memory_copy (mem, offset, left);
1489 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1490 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1491 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1492 gst_memory_unref (mem);
1494 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1507 * @buffer: a #GstBuffer.
1508 * @info: (out): info about the mapping
1509 * @flags: flags for the mapping
1511 * This function fills @info with the #GstMapInfo of all merged memory
1512 * blocks in @buffer.
1514 * @flags describe the desired access of the memory. When @flags is
1515 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1516 * gst_buffer_is_writable()).
1518 * When @buffer is writable but the memory isn't, a writable copy will
1519 * automatically be created and returned. The readonly copy of the
1520 * buffer memory will then also be replaced with this writable copy.
1522 * The memory in @info should be unmapped with gst_buffer_unmap() after
1525 * Returns: %TRUE if the map succeeded and @info contains valid data.
1528 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1530 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1534 * gst_buffer_map_range:
1535 * @buffer: a #GstBuffer.
1538 * @info: (out): info about the mapping
1539 * @flags: flags for the mapping
1541 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1542 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1543 * from @idx are merged and mapped.
1545 * @flags describe the desired access of the memory. When @flags is
1546 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1547 * gst_buffer_is_writable()).
1549 * When @buffer is writable but the memory isn't, a writable copy will
1550 * automatically be created and returned. The readonly copy of the buffer memory
1551 * will then also be replaced with this writable copy.
1553 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1555 * Returns: %TRUE if the map succeeded and @info contains valid
1559 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1560 GstMapInfo * info, GstMapFlags flags)
1562 GstMemory *mem, *nmem;
1563 gboolean write, writable;
1566 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1567 g_return_val_if_fail (info != NULL, FALSE);
1568 len = GST_BUFFER_MEM_LEN (buffer);
1569 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1570 (length == -1 && idx < len) || (length > 0
1571 && length + idx <= len), FALSE);
1573 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1574 buffer, idx, length, flags);
1576 write = (flags & GST_MAP_WRITE) != 0;
1577 writable = gst_buffer_is_writable (buffer);
1579 /* check if we can write when asked for write access */
1580 if (G_UNLIKELY (write && !writable))
1586 mem = _get_merged_memory (buffer, idx, length);
1587 if (G_UNLIKELY (mem == NULL))
1590 /* now try to map */
1591 nmem = gst_memory_make_mapped (mem, info, flags);
1592 if (G_UNLIKELY (nmem == NULL))
1595 /* if we merged or when the map returned a different memory, we try to replace
1596 * the memory in the buffer */
1597 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1598 /* if the buffer is writable, replace the memory */
1600 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1603 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1604 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1613 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1614 g_critical ("write map requested on non-writable buffer");
1615 memset (info, 0, sizeof (GstMapInfo));
1620 /* empty buffer, we need to return NULL */
1621 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1622 memset (info, 0, sizeof (GstMapInfo));
1627 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1628 memset (info, 0, sizeof (GstMapInfo));
1635 * @buffer: a #GstBuffer.
1636 * @info: a #GstMapInfo
1638 * Release the memory previously mapped with gst_buffer_map().
1641 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1643 g_return_if_fail (GST_IS_BUFFER (buffer));
1644 g_return_if_fail (info != NULL);
1646 /* we need to check for NULL, it is possible that we tried to map a buffer
1647 * without memory and we should be able to unmap that fine */
1648 if (G_LIKELY (info->memory)) {
1649 gst_memory_unmap (info->memory, info);
1650 gst_memory_unref (info->memory);
1656 * @buffer: a #GstBuffer.
1657 * @offset: the offset to fill
1658 * @src: (array length=size) (element-type guint8): the source address
1659 * @size: the size to fill
1661 * Copy @size bytes from @src to @buffer at @offset.
1663 * Returns: The amount of bytes copied. This value can be lower than @size
1664 * when @buffer did not contain enough data.
1667 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1671 const guint8 *ptr = src;
1673 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1674 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1675 g_return_val_if_fail (src != NULL || size == 0, 0);
1677 GST_CAT_LOG (GST_CAT_BUFFER,
1678 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1681 len = GST_BUFFER_MEM_LEN (buffer);
1684 for (i = 0; i < len && left > 0; i++) {
1689 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1690 if (info.size > offset) {
1691 /* we have enough */
1692 tocopy = MIN (info.size - offset, left);
1693 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1698 /* offset past buffer, skip */
1699 offset -= info.size;
1701 gst_memory_unmap (mem, &info);
1707 * gst_buffer_extract:
1708 * @buffer: a #GstBuffer.
1709 * @offset: the offset to extract
1710 * @dest: the destination address
1711 * @size: the size to extract
1713 * Copy @size bytes starting from @offset in @buffer to @dest.
1715 * Returns: The amount of bytes extracted. This value can be lower than @size
1716 * when @buffer did not contain enough data.
1719 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1724 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1725 g_return_val_if_fail (dest != NULL, 0);
1727 GST_CAT_LOG (GST_CAT_BUFFER,
1728 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1731 len = GST_BUFFER_MEM_LEN (buffer);
1734 for (i = 0; i < len && left > 0; i++) {
1739 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1740 if (info.size > offset) {
1741 /* we have enough */
1742 tocopy = MIN (info.size - offset, left);
1743 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1748 /* offset past buffer, skip */
1749 offset -= info.size;
1751 gst_memory_unmap (mem, &info);
1757 * gst_buffer_memcmp:
1758 * @buffer: a #GstBuffer.
1759 * @offset: the offset in @buffer
1760 * @mem: (array length=size) (element-type guint8): the memory to compare
1761 * @size: the size to compare
1763 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1765 * Returns: 0 if the memory is equal.
1768 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1772 const guint8 *ptr = mem;
1775 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1776 g_return_val_if_fail (mem != NULL, 0);
1778 GST_CAT_LOG (GST_CAT_BUFFER,
1779 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1782 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1785 len = GST_BUFFER_MEM_LEN (buffer);
1787 for (i = 0; i < len && size > 0 && res == 0; i++) {
1792 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1793 if (info.size > offset) {
1794 /* we have enough */
1795 tocmp = MIN (info.size - offset, size);
1796 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1801 /* offset past buffer, skip */
1802 offset -= info.size;
1804 gst_memory_unmap (mem, &info);
1810 * gst_buffer_memset:
1811 * @buffer: a #GstBuffer.
1812 * @offset: the offset in @buffer
1813 * @val: the value to set
1814 * @size: the size to set
1816 * Fill @buf with @size bytes with @val starting from @offset.
1818 * Returns: The amount of bytes filled. This value can be lower than @size
1819 * when @buffer did not contain enough data.
1822 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1826 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1827 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1829 GST_CAT_LOG (GST_CAT_BUFFER,
1830 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1831 buffer, offset, val, size);
1833 len = GST_BUFFER_MEM_LEN (buffer);
1836 for (i = 0; i < len && left > 0; i++) {
1841 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1842 if (info.size > offset) {
1843 /* we have enough */
1844 toset = MIN (info.size - offset, left);
1845 memset ((guint8 *) info.data + offset, val, toset);
1849 /* offset past buffer, skip */
1850 offset -= info.size;
1852 gst_memory_unmap (mem, &info);
1858 * gst_buffer_copy_region:
1859 * @parent: a #GstBuffer.
1860 * @flags: the #GstBufferCopyFlags
1861 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1863 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
1866 * Creates a sub-buffer from @parent at @offset and @size.
1867 * This sub-buffer uses the actual memory space of the parent buffer.
1868 * This function will copy the offset and timestamp fields when the
1869 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1870 * #GST_BUFFER_OFFSET_NONE.
1871 * If @offset equals 0 and @size equals the total size of @buffer, the
1872 * duration and offset end fields are also copied. If not they will be set
1873 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1877 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
1881 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1882 gsize offset, gsize size)
1886 g_return_val_if_fail (buffer != NULL, NULL);
1888 /* create the new buffer */
1889 copy = gst_buffer_new ();
1891 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1892 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1894 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1895 gst_buffer_replace (©, NULL);
1901 * gst_buffer_append:
1902 * @buf1: (transfer full): the first source #GstBuffer to append.
1903 * @buf2: (transfer full): the second source #GstBuffer to append.
1905 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1906 * concatenation of the memory of @buf1 and @buf2.
1908 * Returns: (transfer full): the new #GstBuffer that contains the memory
1909 * of the two source buffers.
1912 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1914 return gst_buffer_append_region (buf1, buf2, 0, -1);
1918 * gst_buffer_append_region:
1919 * @buf1: (transfer full): the first source #GstBuffer to append.
1920 * @buf2: (transfer full): the second source #GstBuffer to append.
1921 * @offset: the offset in @buf2
1922 * @size: the size or -1 of @buf2
1924 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1925 * contain a concatenation of the memory of @buf1 and the requested region of
1928 * Returns: (transfer full): the new #GstBuffer that contains the memory
1929 * of the two source buffers.
1932 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
1937 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1938 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1940 buf1 = gst_buffer_make_writable (buf1);
1941 buf2 = gst_buffer_make_writable (buf2);
1943 gst_buffer_resize (buf2, offset, size);
1945 len = GST_BUFFER_MEM_LEN (buf2);
1946 for (i = 0; i < len; i++) {
1949 mem = GST_BUFFER_MEM_PTR (buf2, i);
1950 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1951 _memory_add (buf1, -1, mem, FALSE);
1954 GST_BUFFER_MEM_LEN (buf2) = 0;
1955 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
1956 gst_buffer_unref (buf2);
1962 * gst_buffer_get_meta:
1963 * @buffer: a #GstBuffer
1964 * @api: the #GType of an API
1966 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
1967 * returned. If multiple metadata with the given @api are attached to this
1968 * buffer only the first one is returned. To handle multiple metadata with a
1969 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
1970 * and check the meta->info.api member for the API type.
1972 * Returns: (transfer none) (nullable): the metadata for @api on
1976 gst_buffer_get_meta (GstBuffer * buffer, GType api)
1979 GstMeta *result = NULL;
1981 g_return_val_if_fail (buffer != NULL, NULL);
1982 g_return_val_if_fail (api != 0, NULL);
1984 /* find GstMeta of the requested API */
1985 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
1986 GstMeta *meta = &item->meta;
1987 if (meta->info->api == api) {
1996 * gst_buffer_add_meta:
1997 * @buffer: a #GstBuffer
1998 * @info: a #GstMetaInfo
1999 * @params: params for @info
2001 * Add metadata for @info to @buffer using the parameters in @params.
2003 * Returns: (transfer none): the metadata for the api in @info on @buffer.
2006 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2010 GstMeta *result = NULL;
2013 g_return_val_if_fail (buffer != NULL, NULL);
2014 g_return_val_if_fail (info != NULL, NULL);
2015 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2017 /* create a new slice */
2018 size = ITEM_SIZE (info);
2019 item = g_slice_alloc (size);
2020 result = &item->meta;
2021 result->info = info;
2022 result->flags = GST_META_FLAG_NONE;
2024 GST_CAT_DEBUG (GST_CAT_BUFFER,
2025 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2026 g_type_name (info->type), info->size);
2028 /* call the init_func when needed */
2029 if (info->init_func)
2030 if (!info->init_func (result, params, buffer))
2033 /* and add to the list of metadata */
2034 item->next = GST_BUFFER_META (buffer);
2035 GST_BUFFER_META (buffer) = item;
2041 g_slice_free1 (size, item);
2047 * gst_buffer_remove_meta:
2048 * @buffer: a #GstBuffer
2051 * Remove the metadata for @meta on @buffer.
2053 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2054 * metadata was on @buffer.
2057 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2059 GstMetaItem *walk, *prev;
2061 g_return_val_if_fail (buffer != NULL, FALSE);
2062 g_return_val_if_fail (meta != NULL, FALSE);
2063 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2064 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2067 /* find the metadata and delete */
2068 prev = GST_BUFFER_META (buffer);
2069 for (walk = prev; walk; walk = walk->next) {
2070 GstMeta *m = &walk->meta;
2072 const GstMetaInfo *info = meta->info;
2074 /* remove from list */
2075 if (GST_BUFFER_META (buffer) == walk)
2076 GST_BUFFER_META (buffer) = walk->next;
2078 prev->next = walk->next;
2079 /* call free_func if any */
2080 if (info->free_func)
2081 info->free_func (m, buffer);
2083 /* and free the slice */
2084 g_slice_free1 (ITEM_SIZE (info), walk);
2089 return walk != NULL;
2093 * gst_buffer_iterate_meta:
2094 * @buffer: a #GstBuffer
2095 * @state: an opaque state pointer
2097 * Retrieve the next #GstMeta after @current. If @state points
2098 * to %NULL, the first metadata is returned.
2100 * @state will be updated with an opaque state pointer
2102 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2103 * when there are no more items.
2106 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2110 g_return_val_if_fail (buffer != NULL, NULL);
2111 g_return_val_if_fail (state != NULL, NULL);
2113 meta = (GstMetaItem **) state;
2115 /* state NULL, move to first item */
2116 *meta = GST_BUFFER_META (buffer);
2118 /* state !NULL, move to next item in list */
2119 *meta = (*meta)->next;
2122 return &(*meta)->meta;
2128 * gst_buffer_foreach_meta:
2129 * @buffer: a #GstBuffer
2130 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2131 * @user_data: (closure): user data passed to @func
2133 * Call @func with @user_data for each meta in @buffer.
2135 * @func can modify the passed meta pointer or its contents. The return value
2136 * of @func define if this function returns or if the remaining metadata items
2137 * in the buffer should be skipped.
2139 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2142 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2145 GstMetaItem *walk, *prev, *next;
2146 gboolean res = TRUE;
2148 g_return_val_if_fail (buffer != NULL, FALSE);
2149 g_return_val_if_fail (func != NULL, FALSE);
2151 /* find the metadata and delete */
2152 prev = GST_BUFFER_META (buffer);
2153 for (walk = prev; walk; walk = next) {
2156 m = new = &walk->meta;
2159 res = func (buffer, &new, user_data);
2162 const GstMetaInfo *info = m->info;
2164 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2165 g_type_name (info->type));
2167 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2168 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2171 /* remove from list */
2172 if (GST_BUFFER_META (buffer) == walk)
2173 GST_BUFFER_META (buffer) = next;
2177 /* call free_func if any */
2178 if (info->free_func)
2179 info->free_func (m, buffer);
2181 /* and free the slice */
2182 g_slice_free1 (ITEM_SIZE (info), walk);
2191 * gst_buffer_extract_dup:
2192 * @buffer: a #GstBuffer
2193 * @offset: the offset to extract
2194 * @size: the size to extract
2195 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2196 * the destination array will be written.
2197 * @dest_size: (out): A location where the size of @dest can be written
2199 * Extracts a copy of at most @size bytes the data at @offset into a #GBytes.
2200 * @dest must be freed using g_free() when done.
2206 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2207 gpointer * dest, gsize * dest_size)
2211 real_size = gst_buffer_get_size (buffer);
2213 *dest = g_malloc (MIN (real_size - offset, size));
2215 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);