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);
287 /* transfer full for return and transfer none for @mem */
288 static inline GstMemory *
289 _memory_get_exclusive_reference (GstMemory * mem)
291 GstMemory *ret = NULL;
293 if (gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE)) {
294 ret = gst_memory_ref (mem);
296 /* we cannot take another exclusive lock as the memory is already
297 * locked WRITE + EXCLUSIVE according to part-miniobject.txt */
298 ret = gst_memory_copy (mem, 0, -1);
301 if (!gst_memory_lock (ret, GST_LOCK_FLAG_EXCLUSIVE)) {
302 gst_memory_unref (ret);
309 GST_CAT_WARNING (GST_CAT_BUFFER, "Failed to acquire an exclusive lock for "
316 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem)
318 guint i, len = GST_BUFFER_MEM_LEN (buffer);
320 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p", buffer, idx, mem);
322 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
323 /* too many buffer, span them. */
324 /* FIXME, there is room for improvement here: We could only try to merge
325 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
326 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
327 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
329 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
330 /* we now have 1 single spanned buffer */
337 for (i = len; i > idx; i--) {
338 /* move buffers to insert, FIXME, we need to insert first and then merge */
339 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
341 /* and insert the new buffer */
342 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
343 GST_BUFFER_MEM_LEN (buffer) = len + 1;
345 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
348 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
351 _priv_gst_buffer_initialize (void)
353 _gst_buffer_type = gst_buffer_get_type ();
357 * gst_buffer_get_max_memory:
359 * Get the maximum amount of memory blocks that a buffer can hold. This is a
360 * compile time constant that can be queried with the function.
362 * When more memory blocks are added, existing memory blocks will be merged
363 * together to make room for the new block.
365 * Returns: the maximum amount of memory blocks that a buffer can hold.
370 gst_buffer_get_max_memory (void)
372 return GST_BUFFER_MEM_MAX;
376 * gst_buffer_copy_into:
377 * @dest: a destination #GstBuffer
378 * @src: a source #GstBuffer
379 * @flags: flags indicating what metadata fields should be copied.
380 * @offset: offset to copy from
381 * @size: total size to copy. If -1, all data is copied.
383 * Copies the information from @src into @dest.
385 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
386 * the memory from @src will be appended to @dest.
388 * @flags indicate which fields will be copied.
390 * Returns: %TRUE if the copying succeeded, %FALSE otherwise.
393 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
394 GstBufferCopyFlags flags, gsize offset, gsize size)
398 gboolean region = FALSE;
400 g_return_val_if_fail (dest != NULL, FALSE);
401 g_return_val_if_fail (src != NULL, FALSE);
403 /* nothing to copy if the buffers are the same */
404 if (G_UNLIKELY (dest == src))
407 g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
409 bufsize = gst_buffer_get_size (src);
410 g_return_val_if_fail (bufsize >= offset, FALSE);
414 size = bufsize - offset;
417 g_return_val_if_fail (bufsize >= offset + size, FALSE);
419 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
420 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
423 if (flags & GST_BUFFER_COPY_FLAGS) {
425 guint flags_mask = ~GST_BUFFER_FLAG_TAG_MEMORY;
427 GST_MINI_OBJECT_FLAGS (dest) =
428 (GST_MINI_OBJECT_FLAGS (src) & flags_mask) |
429 (GST_MINI_OBJECT_FLAGS (dest) & ~flags_mask);
432 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
434 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
435 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
436 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
437 if (size == bufsize) {
438 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
439 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
442 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
443 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
444 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
445 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
446 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
450 if (flags & GST_BUFFER_COPY_MEMORY) {
451 gsize skip, left, len, dest_len, i, bsize;
454 deep = flags & GST_BUFFER_COPY_DEEP;
456 len = GST_BUFFER_MEM_LEN (src);
457 dest_len = GST_BUFFER_MEM_LEN (dest);
461 /* copy and make regions of the memory */
462 for (i = 0; i < len && left > 0; i++) {
463 GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
465 bsize = gst_memory_get_sizes (mem, NULL, NULL);
468 /* don't copy buffer */
471 GstMemory *newmem = NULL;
474 tocopy = MIN (bsize - skip, left);
476 if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
477 /* we need to clip something */
478 newmem = gst_memory_share (mem, skip, tocopy);
480 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
485 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
486 /* deep copy or we're not allowed to share this memory
487 * between buffers, always copy then */
488 newmem = gst_memory_copy (mem, skip, tocopy);
490 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
493 } else if (!newmem) {
494 newmem = _memory_get_exclusive_reference (mem);
498 gst_buffer_remove_memory_range (dest, dest_len, -1);
502 _memory_add (dest, -1, newmem);
506 if (flags & GST_BUFFER_COPY_MERGE) {
509 len = GST_BUFFER_MEM_LEN (dest);
510 mem = _get_merged_memory (dest, 0, len);
512 gst_buffer_remove_memory_range (dest, dest_len, -1);
515 _replace_memory (dest, len, 0, len, mem);
519 if (flags & GST_BUFFER_COPY_META) {
520 /* NOTE: GstGLSyncMeta copying relies on the meta
521 * being copied now, after the buffer data,
522 * so this has to happen last */
523 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
524 GstMeta *meta = &walk->meta;
525 const GstMetaInfo *info = meta->info;
527 if (info->transform_func) {
528 GstMetaTransformCopy copy_data;
530 copy_data.region = region;
531 copy_data.offset = offset;
532 copy_data.size = size;
534 if (!info->transform_func (dest, meta, src,
535 _gst_meta_transform_copy, ©_data)) {
536 GST_CAT_ERROR (GST_CAT_BUFFER,
537 "failed to copy meta %p of API type %s", meta,
538 g_type_name (info->api));
548 gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
552 g_return_val_if_fail (buffer != NULL, NULL);
554 /* create a fresh new buffer */
555 copy = gst_buffer_new ();
557 /* copy what the 'flags' want from our parent */
558 /* FIXME why we can't pass const to gst_buffer_copy_into() ? */
559 if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
560 gst_buffer_replace (©, NULL);
563 GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
569 _gst_buffer_copy (const GstBuffer * buffer)
571 return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
575 * gst_buffer_copy_deep:
576 * @buf: a #GstBuffer.
578 * Create a copy of the given buffer. This will make a newly allocated
579 * copy of the data the source buffer contains.
581 * Returns: (transfer full): a new copy of @buf.
586 gst_buffer_copy_deep (const GstBuffer * buffer)
588 return gst_buffer_copy_with_flags (buffer,
589 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
592 /* the default dispose function revives the buffer and returns it to the
593 * pool when there is a pool */
595 _gst_buffer_dispose (GstBuffer * buffer)
599 /* no pool, do free */
600 if ((pool = buffer->pool) == NULL)
603 /* keep the buffer alive */
604 gst_buffer_ref (buffer);
605 /* return the buffer to the pool */
606 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
607 gst_buffer_pool_release_buffer (pool, buffer);
613 _gst_buffer_free (GstBuffer * buffer)
615 GstMetaItem *walk, *next;
619 g_return_if_fail (buffer != NULL);
621 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
624 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
625 GstMeta *meta = &walk->meta;
626 const GstMetaInfo *info = meta->info;
628 /* call free_func if any */
630 info->free_func (meta, buffer);
633 /* and free the slice */
634 g_slice_free1 (ITEM_SIZE (info), walk);
637 /* get the size, when unreffing the memory, we could also unref the buffer
639 msize = GST_BUFFER_SLICE_SIZE (buffer);
641 /* free our memory */
642 len = GST_BUFFER_MEM_LEN (buffer);
643 for (i = 0; i < len; i++) {
644 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
645 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
648 /* we set msize to 0 when the buffer is part of the memory block */
651 memset (buffer, 0xff, msize);
653 g_slice_free1 (msize, buffer);
655 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
660 gst_buffer_init (GstBufferImpl * buffer, gsize size)
662 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
663 (GstMiniObjectCopyFunction) _gst_buffer_copy,
664 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
665 (GstMiniObjectFreeFunction) _gst_buffer_free);
667 GST_BUFFER_SLICE_SIZE (buffer) = size;
669 GST_BUFFER (buffer)->pool = NULL;
670 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
671 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
672 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
673 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
674 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
676 GST_BUFFER_MEM_LEN (buffer) = 0;
677 GST_BUFFER_META (buffer) = NULL;
683 * Creates a newly allocated buffer without any data.
687 * Returns: (transfer full): the new #GstBuffer.
690 gst_buffer_new (void)
692 GstBufferImpl *newbuf;
694 newbuf = g_slice_new (GstBufferImpl);
695 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
697 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
699 return GST_BUFFER_CAST (newbuf);
703 * gst_buffer_new_allocate:
704 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
706 * @size: the size in bytes of the new buffer's data.
707 * @params: (transfer none) (allow-none): optional parameters
709 * Tries to create a newly allocated buffer with data of the given size and
710 * extra parameters from @allocator. If the requested amount of memory can't be
711 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
713 * When @allocator is %NULL, the default memory allocator will be used.
715 * Note that when @size == 0, the buffer will not have memory associated with it.
719 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
720 * the memory couldn't be allocated.
723 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
724 GstAllocationParams * params)
735 mem = gst_allocator_alloc (allocator, size, params);
736 if (G_UNLIKELY (mem == NULL))
742 newbuf = gst_buffer_new ();
745 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
746 _memory_add (newbuf, -1, mem);
749 GST_CAT_LOG (GST_CAT_BUFFER,
750 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
755 asize = sizeof (GstBufferImpl) + size;
756 data = g_slice_alloc (asize);
757 if (G_UNLIKELY (data == NULL))
760 newbuf = GST_BUFFER_CAST (data);
762 gst_buffer_init ((GstBufferImpl *) data, asize);
764 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
766 _memory_add (newbuf, -1, mem, TRUE);
771 /* allocate memory and buffer, it might be interesting to do this but there
772 * are many complications. We need to keep the memory mapped to access the
773 * buffer fields and the memory for the buffer might be just very slow. We
774 * also need to do some more magic to get the alignment right. */
775 asize = sizeof (GstBufferImpl) + size;
776 mem = gst_allocator_alloc (allocator, asize, align);
777 if (G_UNLIKELY (mem == NULL))
780 /* map the data part and init the buffer in it, set the buffer size to 0 so
781 * that a finalize won't free the buffer */
782 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
783 gst_buffer_init ((GstBufferImpl *) data, 0);
784 gst_memory_unmap (mem);
786 /* strip off the buffer */
787 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
789 newbuf = GST_BUFFER_CAST (data);
790 GST_BUFFER_BUFMEM (newbuf) = mem;
793 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
795 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
802 GST_CAT_WARNING (GST_CAT_BUFFER,
803 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
809 * gst_buffer_new_wrapped_full:
810 * @flags: #GstMemoryFlags
811 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
812 * @maxsize: allocated size of @data
813 * @offset: offset in @data
814 * @size: size of valid data
815 * @user_data: (allow-none): user_data
816 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
818 * Allocate a new buffer that wraps the given memory. @data must point to
819 * @maxsize of memory, the wrapped buffer will have the region from @offset and
822 * When the buffer is destroyed, @notify will be called with @user_data.
824 * The prefix/padding must be filled with 0 if @flags contains
825 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
827 * Returns: (transfer full): a new #GstBuffer
830 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
831 gsize maxsize, gsize offset, gsize size, gpointer user_data,
832 GDestroyNotify notify)
837 newbuf = gst_buffer_new ();
839 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
841 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
842 _memory_add (newbuf, -1, mem);
843 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
849 * gst_buffer_new_wrapped:
850 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
851 * @size: allocated size of @data
853 * Creates a new buffer that wraps the given @data. The memory will be freed
854 * with g_free and will be marked writable.
858 * Returns: (transfer full): a new #GstBuffer
861 gst_buffer_new_wrapped (gpointer data, gsize size)
863 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
867 * gst_buffer_n_memory:
868 * @buffer: a #GstBuffer.
870 * Get the amount of memory blocks that this buffer has. This amount is never
871 * larger than what gst_buffer_get_max_memory() returns.
873 * Returns: (transfer full): the amount of memory block in this buffer.
876 gst_buffer_n_memory (GstBuffer * buffer)
878 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
880 return GST_BUFFER_MEM_LEN (buffer);
884 * gst_buffer_prepend_memory:
885 * @buffer: a #GstBuffer.
886 * @mem: (transfer full): a #GstMemory.
888 * Prepend the memory block @mem to @buffer. This function takes
889 * ownership of @mem and thus doesn't increase its refcount.
891 * This function is identical to gst_buffer_insert_memory() with an index of 0.
892 * See gst_buffer_insert_memory() for more details.
895 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
897 gst_buffer_insert_memory (buffer, 0, mem);
901 * gst_buffer_append_memory:
902 * @buffer: a #GstBuffer.
903 * @mem: (transfer full): a #GstMemory.
905 * Append the memory block @mem to @buffer. This function takes
906 * ownership of @mem and thus doesn't increase its refcount.
908 * This function is identical to gst_buffer_insert_memory() with an index of -1.
909 * See gst_buffer_insert_memory() for more details.
912 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
914 gst_buffer_insert_memory (buffer, -1, mem);
918 * gst_buffer_insert_memory:
919 * @buffer: a #GstBuffer.
920 * @idx: the index to add the memory at, or -1 to append it to the end
921 * @mem: (transfer full): a #GstMemory.
923 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
924 * of @mem and thus doesn't increase its refcount.
926 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
927 * added, existing memory blocks will automatically be merged to make room for
931 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
935 g_return_if_fail (GST_IS_BUFFER (buffer));
936 g_return_if_fail (gst_buffer_is_writable (buffer));
937 g_return_if_fail (mem != NULL);
938 g_return_if_fail (idx == -1 ||
939 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
941 tmp = _memory_get_exclusive_reference (mem);
942 g_return_if_fail (tmp != NULL);
943 gst_memory_unref (mem);
944 _memory_add (buffer, idx, tmp);
948 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
951 GstMemory *mem, *mapped;
953 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
955 mapped = gst_memory_make_mapped (mem, info, flags);
958 /* memory changed, lock new memory */
959 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
960 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
961 /* unlock old memory */
962 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
963 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
965 gst_memory_unref (mem);
971 * gst_buffer_peek_memory:
972 * @buffer: a #GstBuffer.
975 * Get the memory block at @idx in @buffer. The memory block stays valid until
976 * the memory block in @buffer is removed, replaced or merged, typically with
977 * any call that modifies the memory in @buffer.
979 * Returns: (transfer none): the #GstMemory at @idx.
982 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
986 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
987 len = GST_BUFFER_MEM_LEN (buffer);
988 g_return_val_if_fail (idx < len, NULL);
990 return GST_BUFFER_MEM_PTR (buffer, idx);
994 * gst_buffer_get_memory:
995 * @buffer: a #GstBuffer.
998 * Get the memory block at index @idx in @buffer.
1000 * Returns: (transfer full): a #GstMemory that contains the data of the
1001 * memory block at @idx. Use gst_memory_unref () after usage.
1004 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
1006 return gst_buffer_get_memory_range (buffer, idx, 1);
1010 * gst_buffer_get_all_memory:
1011 * @buffer: a #GstBuffer.
1013 * Get all the memory block in @buffer. The memory blocks will be merged
1014 * into one large #GstMemory.
1016 * Returns: (transfer full): a #GstMemory that contains the merged memory.
1017 * Use gst_memory_unref () after usage.
1020 gst_buffer_get_all_memory (GstBuffer * buffer)
1022 return gst_buffer_get_memory_range (buffer, 0, -1);
1026 * gst_buffer_get_memory_range:
1027 * @buffer: a #GstBuffer.
1031 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
1032 * be merged into one large #GstMemory.
1034 * If @length is -1, all memory starting from @idx is merged.
1036 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
1037 * blocks starting at @idx. Use gst_memory_unref () after usage.
1040 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1044 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1046 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1047 len = GST_BUFFER_MEM_LEN (buffer);
1048 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1049 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1054 return _get_merged_memory (buffer, idx, length);
1058 * gst_buffer_replace_memory:
1059 * @buffer: a #GstBuffer.
1061 * @mem: (transfer full): a #GstMemory
1063 * Replaces the memory block at index @idx in @buffer with @mem.
1066 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1068 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1072 * gst_buffer_replace_all_memory:
1073 * @buffer: a #GstBuffer.
1074 * @mem: (transfer full): a #GstMemory
1076 * Replaces all memory in @buffer with @mem.
1079 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1081 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1085 * gst_buffer_replace_memory_range:
1086 * @buffer: a #GstBuffer.
1088 * @length: a length should not be 0
1089 * @mem: (transfer full): a #GstMemory
1091 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1093 * If @length is -1, all memory starting from @idx will be removed and
1094 * replaced with @mem.
1096 * @buffer should be writable.
1099 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1104 g_return_if_fail (GST_IS_BUFFER (buffer));
1105 g_return_if_fail (gst_buffer_is_writable (buffer));
1107 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1109 len = GST_BUFFER_MEM_LEN (buffer);
1110 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1111 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1116 _replace_memory (buffer, len, idx, length, mem);
1120 * gst_buffer_remove_memory:
1121 * @buffer: a #GstBuffer.
1124 * Remove the memory block in @b at index @i.
1127 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1129 gst_buffer_remove_memory_range (buffer, idx, 1);
1133 * gst_buffer_remove_all_memory:
1134 * @buffer: a #GstBuffer.
1136 * Remove all the memory blocks in @buffer.
1139 gst_buffer_remove_all_memory (GstBuffer * buffer)
1141 gst_buffer_remove_memory_range (buffer, 0, -1);
1145 * gst_buffer_remove_memory_range:
1146 * @buffer: a #GstBuffer.
1150 * Remove @length memory blocks in @buffer starting from @idx.
1152 * @length can be -1, in which case all memory starting from @idx is removed.
1155 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1159 g_return_if_fail (GST_IS_BUFFER (buffer));
1160 g_return_if_fail (gst_buffer_is_writable (buffer));
1162 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1164 len = GST_BUFFER_MEM_LEN (buffer);
1165 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1166 (length == -1 && idx < len) || length + idx <= len);
1171 _replace_memory (buffer, len, idx, length, NULL);
1175 * gst_buffer_find_memory:
1176 * @buffer: a #GstBuffer.
1177 * @offset: an offset
1179 * @idx: (out): pointer to index
1180 * @length: (out): pointer to length
1181 * @skip: (out): pointer to skip
1183 * Find the memory blocks that span @size bytes starting from @offset
1186 * When this function returns %TRUE, @idx will contain the index of the first
1187 * memory block where the byte for @offset can be found and @length contains the
1188 * number of memory blocks containing the @size remaining bytes. @skip contains
1189 * the number of bytes to skip in the memory block at @idx to get to the byte
1192 * @size can be -1 to get all the memory blocks after @idx.
1194 * Returns: %TRUE when @size bytes starting from @offset could be found in
1195 * @buffer and @idx, @length and @skip will be filled.
1198 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1199 guint * idx, guint * length, gsize * skip)
1201 guint i, len, found;
1203 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1204 g_return_val_if_fail (idx != NULL, FALSE);
1205 g_return_val_if_fail (length != NULL, FALSE);
1206 g_return_val_if_fail (skip != NULL, FALSE);
1208 len = GST_BUFFER_MEM_LEN (buffer);
1211 for (i = 0; i < len; i++) {
1215 mem = GST_BUFFER_MEM_PTR (buffer, i);
1216 s = gst_memory_get_sizes (mem, NULL, NULL);
1219 /* block before offset, or empty block, skip */
1222 /* block after offset */
1224 /* first block, remember index and offset */
1228 /* return remaining blocks */
1235 /* count the amount of found bytes */
1237 if (found >= size) {
1238 /* we have enough bytes */
1239 *length = i - *idx + 1;
1248 * gst_buffer_is_memory_range_writable:
1249 * @buffer: a #GstBuffer.
1251 * @length: a length should not be 0
1253 * Check if @length memory blocks in @buffer starting from @idx are writable.
1255 * @length can be -1 to check all the memory blocks after @idx.
1257 * Note that this function does not check if @buffer is writable, use
1258 * gst_buffer_is_writable() to check that if needed.
1260 * Returns: %TRUE if the memory range is writable
1265 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1269 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1271 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1273 len = GST_BUFFER_MEM_LEN (buffer);
1274 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1275 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1283 for (i = 0; i < len; i++) {
1284 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1291 * gst_buffer_is_all_memory_writable:
1292 * @buffer: a #GstBuffer.
1294 * Check if all memory blocks in @buffer are writable.
1296 * Note that this function does not check if @buffer is writable, use
1297 * gst_buffer_is_writable() to check that if needed.
1299 * Returns: %TRUE if all memory blocks in @buffer are writable
1304 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1306 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1310 * gst_buffer_get_sizes:
1311 * @buffer: a #GstBuffer.
1312 * @offset: (out) (allow-none): a pointer to the offset
1313 * @maxsize: (out) (allow-none): a pointer to the maxsize
1315 * Get the total size of the memory blocks in @b.
1317 * When not %NULL, @offset will contain the offset of the data in the
1318 * first memory block in @buffer and @maxsize will contain the sum of
1319 * the size and @offset and the amount of extra padding on the last
1320 * memory block. @offset and @maxsize can be used to resize the
1321 * buffer memory blocks with gst_buffer_resize().
1323 * Returns: total size of the memory blocks in @buffer.
1326 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1328 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1332 * gst_buffer_get_size:
1333 * @buffer: a #GstBuffer.
1335 * Get the total size of the memory blocks in @buffer.
1337 * Returns: total size of the memory blocks in @buffer.
1340 gst_buffer_get_size (GstBuffer * buffer)
1342 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1346 * gst_buffer_get_sizes_range:
1347 * @buffer: a #GstBuffer.
1350 * @offset: (out) (allow-none): a pointer to the offset
1351 * @maxsize: (out) (allow-none): a pointer to the maxsize
1353 * Get the total size of @length memory blocks stating from @idx in @buffer.
1355 * When not %NULL, @offset will contain the offset of the data in the
1356 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1357 * and @offset and the amount of extra padding on the memory block at @idx +
1359 * @offset and @maxsize can be used to resize the buffer memory blocks with
1360 * gst_buffer_resize_range().
1362 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1365 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1366 gsize * offset, gsize * maxsize)
1372 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1373 len = GST_BUFFER_MEM_LEN (buffer);
1374 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1375 (length == -1 && idx < len) || (length + idx <= len), 0);
1380 if (G_LIKELY (length == 1)) {
1382 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1383 size = gst_memory_get_sizes (mem, offset, maxsize);
1389 size = offs = extra = 0;
1390 for (i = idx; i < end; i++) {
1393 mem = GST_BUFFER_MEM_PTR (buffer, i);
1394 s = gst_memory_get_sizes (mem, &o, &ms);
1398 /* first size, take accumulated data before as the offset */
1402 /* save the amount of data after this block */
1403 extra = ms - (o + s);
1405 /* empty block, add as extra */
1412 *maxsize = offs + size + extra;
1418 * gst_buffer_resize:
1419 * @buffer: a #GstBuffer.
1420 * @offset: the offset adjustment
1421 * @size: the new size or -1 to just adjust the offset
1423 * Set the offset and total size of the memory blocks in @buffer.
1426 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1428 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1432 * gst_buffer_set_size:
1433 * @buffer: a #GstBuffer.
1434 * @size: the new size
1436 * Set the total size of the memory blocks in @buffer.
1439 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1441 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1445 * gst_buffer_resize_range:
1446 * @buffer: a #GstBuffer.
1449 * @offset: the offset adjustment
1450 * @size: the new size or -1 to just adjust the offset
1452 * Set the total size of the @length memory blocks starting at @idx in
1455 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1458 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1459 gssize offset, gssize size)
1462 gsize bsize, bufsize, bufoffs, bufmax;
1464 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1465 g_return_val_if_fail (size >= -1, FALSE);
1467 len = GST_BUFFER_MEM_LEN (buffer);
1468 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1469 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1474 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1476 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1477 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1478 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1480 /* we can't go back further than the current offset or past the end of the
1482 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1483 && bufoffs + offset <= bufmax), FALSE);
1485 g_return_val_if_fail (bufsize >= offset, FALSE);
1486 size = bufsize - offset;
1488 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1491 if (offset == 0 && size == bufsize)
1496 for (i = idx; i < end; i++) {
1500 mem = GST_BUFFER_MEM_PTR (buffer, i);
1501 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1504 /* last buffer always gets resized to the remaining size */
1507 /* shrink buffers before the offset */
1508 else if ((gssize) bsize <= offset) {
1510 noffs = offset - bsize;
1513 /* clip other buffers */
1515 left = MIN (bsize - offset, size);
1517 if (offset != 0 || left != bsize) {
1518 if (gst_memory_is_writable (mem)) {
1519 gst_memory_resize (mem, offset, left);
1521 GstMemory *newmem = NULL;
1523 if (!GST_MEMORY_IS_NO_SHARE (mem))
1524 newmem = gst_memory_share (mem, offset, left);
1527 newmem = gst_memory_copy (mem, offset, left);
1532 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1533 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1534 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1535 gst_memory_unref (mem);
1537 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1550 * @buffer: a #GstBuffer.
1551 * @info: (out): info about the mapping
1552 * @flags: flags for the mapping
1554 * This function fills @info with the #GstMapInfo of all merged memory
1555 * blocks in @buffer.
1557 * @flags describe the desired access of the memory. When @flags is
1558 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1559 * gst_buffer_is_writable()).
1561 * When @buffer is writable but the memory isn't, a writable copy will
1562 * automatically be created and returned. The readonly copy of the
1563 * buffer memory will then also be replaced with this writable copy.
1565 * The memory in @info should be unmapped with gst_buffer_unmap() after
1568 * Returns: %TRUE if the map succeeded and @info contains valid data.
1571 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1573 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1577 * gst_buffer_map_range:
1578 * @buffer: a #GstBuffer.
1581 * @info: (out): info about the mapping
1582 * @flags: flags for the mapping
1584 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1585 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1586 * from @idx are merged and mapped.
1588 * @flags describe the desired access of the memory. When @flags is
1589 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1590 * gst_buffer_is_writable()).
1592 * When @buffer is writable but the memory isn't, a writable copy will
1593 * automatically be created and returned. The readonly copy of the buffer memory
1594 * will then also be replaced with this writable copy.
1596 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1598 * Returns: %TRUE if the map succeeded and @info contains valid
1602 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1603 GstMapInfo * info, GstMapFlags flags)
1605 GstMemory *mem, *nmem;
1606 gboolean write, writable;
1609 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1610 g_return_val_if_fail (info != NULL, FALSE);
1611 len = GST_BUFFER_MEM_LEN (buffer);
1612 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1613 (length == -1 && idx < len) || (length > 0
1614 && length + idx <= len), FALSE);
1616 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1617 buffer, idx, length, flags);
1619 write = (flags & GST_MAP_WRITE) != 0;
1620 writable = gst_buffer_is_writable (buffer);
1622 /* check if we can write when asked for write access */
1623 if (G_UNLIKELY (write && !writable))
1629 mem = _get_merged_memory (buffer, idx, length);
1630 if (G_UNLIKELY (mem == NULL))
1633 /* now try to map */
1634 nmem = gst_memory_make_mapped (mem, info, flags);
1635 if (G_UNLIKELY (nmem == NULL))
1638 /* if we merged or when the map returned a different memory, we try to replace
1639 * the memory in the buffer */
1640 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1641 /* if the buffer is writable, replace the memory */
1643 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1646 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1647 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1656 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1657 g_critical ("write map requested on non-writable buffer");
1658 memset (info, 0, sizeof (GstMapInfo));
1663 /* empty buffer, we need to return NULL */
1664 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1665 memset (info, 0, sizeof (GstMapInfo));
1670 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1671 memset (info, 0, sizeof (GstMapInfo));
1678 * @buffer: a #GstBuffer.
1679 * @info: a #GstMapInfo
1681 * Release the memory previously mapped with gst_buffer_map().
1684 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1686 g_return_if_fail (GST_IS_BUFFER (buffer));
1687 g_return_if_fail (info != NULL);
1689 /* we need to check for NULL, it is possible that we tried to map a buffer
1690 * without memory and we should be able to unmap that fine */
1691 if (G_LIKELY (info->memory)) {
1692 gst_memory_unmap (info->memory, info);
1693 gst_memory_unref (info->memory);
1699 * @buffer: a #GstBuffer.
1700 * @offset: the offset to fill
1701 * @src: (array length=size) (element-type guint8): the source address
1702 * @size: the size to fill
1704 * Copy @size bytes from @src to @buffer at @offset.
1706 * Returns: The amount of bytes copied. This value can be lower than @size
1707 * when @buffer did not contain enough data.
1710 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1714 const guint8 *ptr = src;
1716 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1717 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1718 g_return_val_if_fail (src != NULL || size == 0, 0);
1720 GST_CAT_LOG (GST_CAT_BUFFER,
1721 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1724 len = GST_BUFFER_MEM_LEN (buffer);
1727 for (i = 0; i < len && left > 0; i++) {
1732 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1733 if (info.size > offset) {
1734 /* we have enough */
1735 tocopy = MIN (info.size - offset, left);
1736 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1741 /* offset past buffer, skip */
1742 offset -= info.size;
1744 gst_memory_unmap (mem, &info);
1750 * gst_buffer_extract:
1751 * @buffer: a #GstBuffer.
1752 * @offset: the offset to extract
1753 * @dest: the destination address
1754 * @size: the size to extract
1756 * Copy @size bytes starting from @offset in @buffer to @dest.
1758 * Returns: The amount of bytes extracted. This value can be lower than @size
1759 * when @buffer did not contain enough data.
1762 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1767 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1768 g_return_val_if_fail (dest != NULL, 0);
1770 GST_CAT_LOG (GST_CAT_BUFFER,
1771 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1774 len = GST_BUFFER_MEM_LEN (buffer);
1777 for (i = 0; i < len && left > 0; i++) {
1782 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1783 if (info.size > offset) {
1784 /* we have enough */
1785 tocopy = MIN (info.size - offset, left);
1786 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1791 /* offset past buffer, skip */
1792 offset -= info.size;
1794 gst_memory_unmap (mem, &info);
1800 * gst_buffer_memcmp:
1801 * @buffer: a #GstBuffer.
1802 * @offset: the offset in @buffer
1803 * @mem: (array length=size) (element-type guint8): the memory to compare
1804 * @size: the size to compare
1806 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1808 * Returns: 0 if the memory is equal.
1811 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1815 const guint8 *ptr = mem;
1818 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1819 g_return_val_if_fail (mem != NULL, 0);
1821 GST_CAT_LOG (GST_CAT_BUFFER,
1822 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1825 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1828 len = GST_BUFFER_MEM_LEN (buffer);
1830 for (i = 0; i < len && size > 0 && res == 0; i++) {
1835 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1836 if (info.size > offset) {
1837 /* we have enough */
1838 tocmp = MIN (info.size - offset, size);
1839 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1844 /* offset past buffer, skip */
1845 offset -= info.size;
1847 gst_memory_unmap (mem, &info);
1853 * gst_buffer_memset:
1854 * @buffer: a #GstBuffer.
1855 * @offset: the offset in @buffer
1856 * @val: the value to set
1857 * @size: the size to set
1859 * Fill @buf with @size bytes with @val starting from @offset.
1861 * Returns: The amount of bytes filled. This value can be lower than @size
1862 * when @buffer did not contain enough data.
1865 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1869 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1870 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1872 GST_CAT_LOG (GST_CAT_BUFFER,
1873 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1874 buffer, offset, val, size);
1876 len = GST_BUFFER_MEM_LEN (buffer);
1879 for (i = 0; i < len && left > 0; i++) {
1884 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1885 if (info.size > offset) {
1886 /* we have enough */
1887 toset = MIN (info.size - offset, left);
1888 memset ((guint8 *) info.data + offset, val, toset);
1892 /* offset past buffer, skip */
1893 offset -= info.size;
1895 gst_memory_unmap (mem, &info);
1901 * gst_buffer_copy_region:
1902 * @parent: a #GstBuffer.
1903 * @flags: the #GstBufferCopyFlags
1904 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1906 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
1909 * Creates a sub-buffer from @parent at @offset and @size.
1910 * This sub-buffer uses the actual memory space of the parent buffer.
1911 * This function will copy the offset and timestamp fields when the
1912 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1913 * #GST_BUFFER_OFFSET_NONE.
1914 * If @offset equals 0 and @size equals the total size of @buffer, the
1915 * duration and offset end fields are also copied. If not they will be set
1916 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1920 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
1924 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1925 gsize offset, gsize size)
1929 g_return_val_if_fail (buffer != NULL, NULL);
1931 /* create the new buffer */
1932 copy = gst_buffer_new ();
1934 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1935 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1937 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1938 gst_buffer_replace (©, NULL);
1944 * gst_buffer_append:
1945 * @buf1: (transfer full): the first source #GstBuffer to append.
1946 * @buf2: (transfer full): the second source #GstBuffer to append.
1948 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1949 * concatenation of the memory of @buf1 and @buf2.
1951 * Returns: (transfer full): the new #GstBuffer that contains the memory
1952 * of the two source buffers.
1955 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1957 return gst_buffer_append_region (buf1, buf2, 0, -1);
1961 * gst_buffer_append_region:
1962 * @buf1: (transfer full): the first source #GstBuffer to append.
1963 * @buf2: (transfer full): the second source #GstBuffer to append.
1964 * @offset: the offset in @buf2
1965 * @size: the size or -1 of @buf2
1967 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1968 * contain a concatenation of the memory of @buf1 and the requested region of
1971 * Returns: (transfer full): the new #GstBuffer that contains the memory
1972 * of the two source buffers.
1975 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
1980 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1981 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1983 buf1 = gst_buffer_make_writable (buf1);
1984 buf2 = gst_buffer_make_writable (buf2);
1986 gst_buffer_resize (buf2, offset, size);
1988 len = GST_BUFFER_MEM_LEN (buf2);
1989 for (i = 0; i < len; i++) {
1992 mem = GST_BUFFER_MEM_PTR (buf2, i);
1993 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1994 _memory_add (buf1, -1, mem);
1997 GST_BUFFER_MEM_LEN (buf2) = 0;
1998 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
1999 gst_buffer_unref (buf2);
2005 * gst_buffer_get_meta:
2006 * @buffer: a #GstBuffer
2007 * @api: the #GType of an API
2009 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
2010 * returned. If multiple metadata with the given @api are attached to this
2011 * buffer only the first one is returned. To handle multiple metadata with a
2012 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
2013 * and check the meta->info.api member for the API type.
2015 * Returns: (transfer none) (nullable): the metadata for @api on
2019 gst_buffer_get_meta (GstBuffer * buffer, GType api)
2022 GstMeta *result = NULL;
2024 g_return_val_if_fail (buffer != NULL, NULL);
2025 g_return_val_if_fail (api != 0, NULL);
2027 /* find GstMeta of the requested API */
2028 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
2029 GstMeta *meta = &item->meta;
2030 if (meta->info->api == api) {
2039 * gst_buffer_add_meta:
2040 * @buffer: a #GstBuffer
2041 * @info: a #GstMetaInfo
2042 * @params: params for @info
2044 * Add metadata for @info to @buffer using the parameters in @params.
2046 * Returns: (transfer none): the metadata for the api in @info on @buffer.
2049 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2053 GstMeta *result = NULL;
2056 g_return_val_if_fail (buffer != NULL, NULL);
2057 g_return_val_if_fail (info != NULL, NULL);
2058 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2060 /* create a new slice */
2061 size = ITEM_SIZE (info);
2062 item = g_slice_alloc (size);
2063 result = &item->meta;
2064 result->info = info;
2065 result->flags = GST_META_FLAG_NONE;
2067 GST_CAT_DEBUG (GST_CAT_BUFFER,
2068 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2069 g_type_name (info->type), info->size);
2071 /* call the init_func when needed */
2072 if (info->init_func)
2073 if (!info->init_func (result, params, buffer))
2076 /* and add to the list of metadata */
2077 item->next = GST_BUFFER_META (buffer);
2078 GST_BUFFER_META (buffer) = item;
2084 g_slice_free1 (size, item);
2090 * gst_buffer_remove_meta:
2091 * @buffer: a #GstBuffer
2094 * Remove the metadata for @meta on @buffer.
2096 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2097 * metadata was on @buffer.
2100 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2102 GstMetaItem *walk, *prev;
2104 g_return_val_if_fail (buffer != NULL, FALSE);
2105 g_return_val_if_fail (meta != NULL, FALSE);
2106 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2107 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2110 /* find the metadata and delete */
2111 prev = GST_BUFFER_META (buffer);
2112 for (walk = prev; walk; walk = walk->next) {
2113 GstMeta *m = &walk->meta;
2115 const GstMetaInfo *info = meta->info;
2117 /* remove from list */
2118 if (GST_BUFFER_META (buffer) == walk)
2119 GST_BUFFER_META (buffer) = walk->next;
2121 prev->next = walk->next;
2122 /* call free_func if any */
2123 if (info->free_func)
2124 info->free_func (m, buffer);
2126 /* and free the slice */
2127 g_slice_free1 (ITEM_SIZE (info), walk);
2132 return walk != NULL;
2136 * gst_buffer_iterate_meta:
2137 * @buffer: a #GstBuffer
2138 * @state: an opaque state pointer
2140 * Retrieve the next #GstMeta after @current. If @state points
2141 * to %NULL, the first metadata is returned.
2143 * @state will be updated with an opaque state pointer
2145 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2146 * when there are no more items.
2149 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2153 g_return_val_if_fail (buffer != NULL, NULL);
2154 g_return_val_if_fail (state != NULL, NULL);
2156 meta = (GstMetaItem **) state;
2158 /* state NULL, move to first item */
2159 *meta = GST_BUFFER_META (buffer);
2161 /* state !NULL, move to next item in list */
2162 *meta = (*meta)->next;
2165 return &(*meta)->meta;
2171 * gst_buffer_foreach_meta:
2172 * @buffer: a #GstBuffer
2173 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2174 * @user_data: (closure): user data passed to @func
2176 * Call @func with @user_data for each meta in @buffer.
2178 * @func can modify the passed meta pointer or its contents. The return value
2179 * of @func define if this function returns or if the remaining metadata items
2180 * in the buffer should be skipped.
2182 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2185 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2188 GstMetaItem *walk, *prev, *next;
2189 gboolean res = TRUE;
2191 g_return_val_if_fail (buffer != NULL, FALSE);
2192 g_return_val_if_fail (func != NULL, FALSE);
2194 /* find the metadata and delete */
2195 prev = GST_BUFFER_META (buffer);
2196 for (walk = prev; walk; walk = next) {
2199 m = new = &walk->meta;
2202 res = func (buffer, &new, user_data);
2205 const GstMetaInfo *info = m->info;
2207 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2208 g_type_name (info->type));
2210 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2211 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2214 /* remove from list */
2215 if (GST_BUFFER_META (buffer) == walk)
2216 GST_BUFFER_META (buffer) = next;
2220 /* call free_func if any */
2221 if (info->free_func)
2222 info->free_func (m, buffer);
2224 /* and free the slice */
2225 g_slice_free1 (ITEM_SIZE (info), walk);
2234 * gst_buffer_extract_dup:
2235 * @buffer: a #GstBuffer
2236 * @offset: the offset to extract
2237 * @size: the size to extract
2238 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2239 * the destination array will be written.
2240 * @dest_size: (out): A location where the size of @dest can be written
2242 * Extracts a copy of at most @size bytes the data at @offset into a #GBytes.
2243 * @dest must be freed using g_free() when done.
2249 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2250 gpointer * dest, gsize * dest_size)
2254 real_size = gst_buffer_get_size (buffer);
2256 *dest = g_malloc (MIN (real_size - offset, size));
2258 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);