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.
584 gst_buffer_copy_deep (const GstBuffer * buffer)
586 return gst_buffer_copy_with_flags (buffer,
587 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
590 /* the default dispose function revives the buffer and returns it to the
591 * pool when there is a pool */
593 _gst_buffer_dispose (GstBuffer * buffer)
597 /* no pool, do free */
598 if ((pool = buffer->pool) == NULL)
601 /* keep the buffer alive */
602 gst_buffer_ref (buffer);
603 /* return the buffer to the pool */
604 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
605 gst_buffer_pool_release_buffer (pool, buffer);
611 _gst_buffer_free (GstBuffer * buffer)
613 GstMetaItem *walk, *next;
617 g_return_if_fail (buffer != NULL);
619 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
622 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
623 GstMeta *meta = &walk->meta;
624 const GstMetaInfo *info = meta->info;
626 /* call free_func if any */
628 info->free_func (meta, buffer);
631 /* and free the slice */
632 g_slice_free1 (ITEM_SIZE (info), walk);
635 /* get the size, when unreffing the memory, we could also unref the buffer
637 msize = GST_BUFFER_SLICE_SIZE (buffer);
639 /* free our memory */
640 len = GST_BUFFER_MEM_LEN (buffer);
641 for (i = 0; i < len; i++) {
642 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
643 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
646 /* we set msize to 0 when the buffer is part of the memory block */
649 memset (buffer, 0xff, msize);
651 g_slice_free1 (msize, buffer);
653 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
658 gst_buffer_init (GstBufferImpl * buffer, gsize size)
660 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
661 (GstMiniObjectCopyFunction) _gst_buffer_copy,
662 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
663 (GstMiniObjectFreeFunction) _gst_buffer_free);
665 GST_BUFFER_SLICE_SIZE (buffer) = size;
667 GST_BUFFER (buffer)->pool = NULL;
668 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
669 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
670 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
671 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
672 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
674 GST_BUFFER_MEM_LEN (buffer) = 0;
675 GST_BUFFER_META (buffer) = NULL;
681 * Creates a newly allocated buffer without any data.
685 * Returns: (transfer full): the new #GstBuffer.
688 gst_buffer_new (void)
690 GstBufferImpl *newbuf;
692 newbuf = g_slice_new (GstBufferImpl);
693 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
695 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
697 return GST_BUFFER_CAST (newbuf);
701 * gst_buffer_new_allocate:
702 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
704 * @size: the size in bytes of the new buffer's data.
705 * @params: (transfer none) (allow-none): optional parameters
707 * Tries to create a newly allocated buffer with data of the given size and
708 * extra parameters from @allocator. If the requested amount of memory can't be
709 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
711 * When @allocator is %NULL, the default memory allocator will be used.
713 * Note that when @size == 0, the buffer will not have memory associated with it.
717 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
718 * the memory couldn't be allocated.
721 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
722 GstAllocationParams * params)
733 mem = gst_allocator_alloc (allocator, size, params);
734 if (G_UNLIKELY (mem == NULL))
740 newbuf = gst_buffer_new ();
743 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
744 _memory_add (newbuf, -1, mem);
747 GST_CAT_LOG (GST_CAT_BUFFER,
748 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
753 asize = sizeof (GstBufferImpl) + size;
754 data = g_slice_alloc (asize);
755 if (G_UNLIKELY (data == NULL))
758 newbuf = GST_BUFFER_CAST (data);
760 gst_buffer_init ((GstBufferImpl *) data, asize);
762 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
764 _memory_add (newbuf, -1, mem, TRUE);
769 /* allocate memory and buffer, it might be interesting to do this but there
770 * are many complications. We need to keep the memory mapped to access the
771 * buffer fields and the memory for the buffer might be just very slow. We
772 * also need to do some more magic to get the alignment right. */
773 asize = sizeof (GstBufferImpl) + size;
774 mem = gst_allocator_alloc (allocator, asize, align);
775 if (G_UNLIKELY (mem == NULL))
778 /* map the data part and init the buffer in it, set the buffer size to 0 so
779 * that a finalize won't free the buffer */
780 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
781 gst_buffer_init ((GstBufferImpl *) data, 0);
782 gst_memory_unmap (mem);
784 /* strip off the buffer */
785 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
787 newbuf = GST_BUFFER_CAST (data);
788 GST_BUFFER_BUFMEM (newbuf) = mem;
791 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
793 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
800 GST_CAT_WARNING (GST_CAT_BUFFER,
801 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
807 * gst_buffer_new_wrapped_full:
808 * @flags: #GstMemoryFlags
809 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
810 * @maxsize: allocated size of @data
811 * @offset: offset in @data
812 * @size: size of valid data
813 * @user_data: (allow-none): user_data
814 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
816 * Allocate a new buffer that wraps the given memory. @data must point to
817 * @maxsize of memory, the wrapped buffer will have the region from @offset and
820 * When the buffer is destroyed, @notify will be called with @user_data.
822 * The prefix/padding must be filled with 0 if @flags contains
823 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
825 * Returns: (transfer full): a new #GstBuffer
828 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
829 gsize maxsize, gsize offset, gsize size, gpointer user_data,
830 GDestroyNotify notify)
835 newbuf = gst_buffer_new ();
837 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
839 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
840 _memory_add (newbuf, -1, mem);
841 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
847 * gst_buffer_new_wrapped:
848 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
849 * @size: allocated size of @data
851 * Creates a new buffer that wraps the given @data. The memory will be freed
852 * with g_free and will be marked writable.
856 * Returns: (transfer full): a new #GstBuffer
859 gst_buffer_new_wrapped (gpointer data, gsize size)
861 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
865 * gst_buffer_n_memory:
866 * @buffer: a #GstBuffer.
868 * Get the amount of memory blocks that this buffer has. This amount is never
869 * larger than what gst_buffer_get_max_memory() returns.
871 * Returns: (transfer full): the amount of memory block in this buffer.
874 gst_buffer_n_memory (GstBuffer * buffer)
876 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
878 return GST_BUFFER_MEM_LEN (buffer);
882 * gst_buffer_prepend_memory:
883 * @buffer: a #GstBuffer.
884 * @mem: (transfer full): a #GstMemory.
886 * Prepend the memory block @mem to @buffer. This function takes
887 * ownership of @mem and thus doesn't increase its refcount.
889 * This function is identical to gst_buffer_insert_memory() with an index of 0.
890 * See gst_buffer_insert_memory() for more details.
893 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
895 gst_buffer_insert_memory (buffer, 0, mem);
899 * gst_buffer_append_memory:
900 * @buffer: a #GstBuffer.
901 * @mem: (transfer full): a #GstMemory.
903 * Append the memory block @mem to @buffer. This function takes
904 * ownership of @mem and thus doesn't increase its refcount.
906 * This function is identical to gst_buffer_insert_memory() with an index of -1.
907 * See gst_buffer_insert_memory() for more details.
910 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
912 gst_buffer_insert_memory (buffer, -1, mem);
916 * gst_buffer_insert_memory:
917 * @buffer: a #GstBuffer.
918 * @idx: the index to add the memory at, or -1 to append it to the end
919 * @mem: (transfer full): a #GstMemory.
921 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
922 * of @mem and thus doesn't increase its refcount.
924 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
925 * added, existing memory blocks will automatically be merged to make room for
929 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
933 g_return_if_fail (GST_IS_BUFFER (buffer));
934 g_return_if_fail (gst_buffer_is_writable (buffer));
935 g_return_if_fail (mem != NULL);
936 g_return_if_fail (idx == -1 ||
937 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
939 tmp = _memory_get_exclusive_reference (mem);
940 g_return_if_fail (tmp != NULL);
941 gst_memory_unref (mem);
942 _memory_add (buffer, idx, tmp);
946 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
949 GstMemory *mem, *mapped;
951 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
953 mapped = gst_memory_make_mapped (mem, info, flags);
956 /* memory changed, lock new memory */
957 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
958 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
959 /* unlock old memory */
960 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
961 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
963 gst_memory_unref (mem);
969 * gst_buffer_peek_memory:
970 * @buffer: a #GstBuffer.
973 * Get the memory block at @idx in @buffer. The memory block stays valid until
974 * the memory block in @buffer is removed, replaced or merged, typically with
975 * any call that modifies the memory in @buffer.
977 * Returns: (transfer none): the #GstMemory at @idx.
980 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
984 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
985 len = GST_BUFFER_MEM_LEN (buffer);
986 g_return_val_if_fail (idx < len, NULL);
988 return GST_BUFFER_MEM_PTR (buffer, idx);
992 * gst_buffer_get_memory:
993 * @buffer: a #GstBuffer.
996 * Get the memory block at index @idx in @buffer.
998 * Returns: (transfer full): a #GstMemory that contains the data of the
999 * memory block at @idx. Use gst_memory_unref () after usage.
1002 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
1004 return gst_buffer_get_memory_range (buffer, idx, 1);
1008 * gst_buffer_get_all_memory:
1009 * @buffer: a #GstBuffer.
1011 * Get all the memory block in @buffer. The memory blocks will be merged
1012 * into one large #GstMemory.
1014 * Returns: (transfer full): a #GstMemory that contains the merged memory.
1015 * Use gst_memory_unref () after usage.
1018 gst_buffer_get_all_memory (GstBuffer * buffer)
1020 return gst_buffer_get_memory_range (buffer, 0, -1);
1024 * gst_buffer_get_memory_range:
1025 * @buffer: a #GstBuffer.
1029 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
1030 * be merged into one large #GstMemory.
1032 * If @length is -1, all memory starting from @idx is merged.
1034 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
1035 * blocks starting at @idx. Use gst_memory_unref () after usage.
1038 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1042 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1044 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1045 len = GST_BUFFER_MEM_LEN (buffer);
1046 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1047 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1052 return _get_merged_memory (buffer, idx, length);
1056 * gst_buffer_replace_memory:
1057 * @buffer: a #GstBuffer.
1059 * @mem: (transfer full): a #GstMemory
1061 * Replaces the memory block at index @idx in @buffer with @mem.
1064 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1066 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1070 * gst_buffer_replace_all_memory:
1071 * @buffer: a #GstBuffer.
1072 * @mem: (transfer full): a #GstMemory
1074 * Replaces all memory in @buffer with @mem.
1077 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1079 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1083 * gst_buffer_replace_memory_range:
1084 * @buffer: a #GstBuffer.
1086 * @length: a length should not be 0
1087 * @mem: (transfer full): a #GstMemory
1089 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1091 * If @length is -1, all memory starting from @idx will be removed and
1092 * replaced with @mem.
1094 * @buffer should be writable.
1097 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1102 g_return_if_fail (GST_IS_BUFFER (buffer));
1103 g_return_if_fail (gst_buffer_is_writable (buffer));
1105 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1107 len = GST_BUFFER_MEM_LEN (buffer);
1108 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1109 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1114 _replace_memory (buffer, len, idx, length, mem);
1118 * gst_buffer_remove_memory:
1119 * @buffer: a #GstBuffer.
1122 * Remove the memory block in @b at index @i.
1125 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1127 gst_buffer_remove_memory_range (buffer, idx, 1);
1131 * gst_buffer_remove_all_memory:
1132 * @buffer: a #GstBuffer.
1134 * Remove all the memory blocks in @buffer.
1137 gst_buffer_remove_all_memory (GstBuffer * buffer)
1139 gst_buffer_remove_memory_range (buffer, 0, -1);
1143 * gst_buffer_remove_memory_range:
1144 * @buffer: a #GstBuffer.
1148 * Remove @length memory blocks in @buffer starting from @idx.
1150 * @length can be -1, in which case all memory starting from @idx is removed.
1153 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1157 g_return_if_fail (GST_IS_BUFFER (buffer));
1158 g_return_if_fail (gst_buffer_is_writable (buffer));
1160 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1162 len = GST_BUFFER_MEM_LEN (buffer);
1163 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1164 (length == -1 && idx < len) || length + idx <= len);
1169 _replace_memory (buffer, len, idx, length, NULL);
1173 * gst_buffer_find_memory:
1174 * @buffer: a #GstBuffer.
1175 * @offset: an offset
1177 * @idx: (out): pointer to index
1178 * @length: (out): pointer to length
1179 * @skip: (out): pointer to skip
1181 * Find the memory blocks that span @size bytes starting from @offset
1184 * When this function returns %TRUE, @idx will contain the index of the first
1185 * memory block where the byte for @offset can be found and @length contains the
1186 * number of memory blocks containing the @size remaining bytes. @skip contains
1187 * the number of bytes to skip in the memory block at @idx to get to the byte
1190 * @size can be -1 to get all the memory blocks after @idx.
1192 * Returns: %TRUE when @size bytes starting from @offset could be found in
1193 * @buffer and @idx, @length and @skip will be filled.
1196 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1197 guint * idx, guint * length, gsize * skip)
1199 guint i, len, found;
1201 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1202 g_return_val_if_fail (idx != NULL, FALSE);
1203 g_return_val_if_fail (length != NULL, FALSE);
1204 g_return_val_if_fail (skip != NULL, FALSE);
1206 len = GST_BUFFER_MEM_LEN (buffer);
1209 for (i = 0; i < len; i++) {
1213 mem = GST_BUFFER_MEM_PTR (buffer, i);
1214 s = gst_memory_get_sizes (mem, NULL, NULL);
1217 /* block before offset, or empty block, skip */
1220 /* block after offset */
1222 /* first block, remember index and offset */
1226 /* return remaining blocks */
1233 /* count the amount of found bytes */
1235 if (found >= size) {
1236 /* we have enough bytes */
1237 *length = i - *idx + 1;
1246 * gst_buffer_is_memory_range_writable:
1247 * @buffer: a #GstBuffer.
1249 * @length: a length should not be 0
1251 * Check if @length memory blocks in @buffer starting from @idx are writable.
1253 * @length can be -1 to check all the memory blocks after @idx.
1255 * Note that this function does not check if @buffer is writable, use
1256 * gst_buffer_is_writable() to check that if needed.
1258 * Returns: %TRUE if the memory range is writable
1263 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1267 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1269 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1271 len = GST_BUFFER_MEM_LEN (buffer);
1272 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1273 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1281 for (i = 0; i < len; i++) {
1282 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1289 * gst_buffer_is_all_memory_writable:
1290 * @buffer: a #GstBuffer.
1292 * Check if all memory blocks in @buffer are writable.
1294 * Note that this function does not check if @buffer is writable, use
1295 * gst_buffer_is_writable() to check that if needed.
1297 * Returns: %TRUE if all memory blocks in @buffer are writable
1302 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1304 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1308 * gst_buffer_get_sizes:
1309 * @buffer: a #GstBuffer.
1310 * @offset: (out) (allow-none): a pointer to the offset
1311 * @maxsize: (out) (allow-none): a pointer to the maxsize
1313 * Get the total size of the memory blocks in @b.
1315 * When not %NULL, @offset will contain the offset of the data in the
1316 * first memory block in @buffer and @maxsize will contain the sum of
1317 * the size and @offset and the amount of extra padding on the last
1318 * memory block. @offset and @maxsize can be used to resize the
1319 * buffer memory blocks with gst_buffer_resize().
1321 * Returns: total size of the memory blocks in @buffer.
1324 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1326 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1330 * gst_buffer_get_size:
1331 * @buffer: a #GstBuffer.
1333 * Get the total size of the memory blocks in @buffer.
1335 * Returns: total size of the memory blocks in @buffer.
1338 gst_buffer_get_size (GstBuffer * buffer)
1340 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1344 * gst_buffer_get_sizes_range:
1345 * @buffer: a #GstBuffer.
1348 * @offset: (out) (allow-none): a pointer to the offset
1349 * @maxsize: (out) (allow-none): a pointer to the maxsize
1351 * Get the total size of @length memory blocks stating from @idx in @buffer.
1353 * When not %NULL, @offset will contain the offset of the data in the
1354 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1355 * and @offset and the amount of extra padding on the memory block at @idx +
1357 * @offset and @maxsize can be used to resize the buffer memory blocks with
1358 * gst_buffer_resize_range().
1360 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1363 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1364 gsize * offset, gsize * maxsize)
1370 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1371 len = GST_BUFFER_MEM_LEN (buffer);
1372 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1373 (length == -1 && idx < len) || (length + idx <= len), 0);
1378 if (G_LIKELY (length == 1)) {
1380 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1381 size = gst_memory_get_sizes (mem, offset, maxsize);
1387 size = offs = extra = 0;
1388 for (i = idx; i < end; i++) {
1391 mem = GST_BUFFER_MEM_PTR (buffer, i);
1392 s = gst_memory_get_sizes (mem, &o, &ms);
1396 /* first size, take accumulated data before as the offset */
1400 /* save the amount of data after this block */
1401 extra = ms - (o + s);
1403 /* empty block, add as extra */
1410 *maxsize = offs + size + extra;
1416 * gst_buffer_resize:
1417 * @buffer: a #GstBuffer.
1418 * @offset: the offset adjustment
1419 * @size: the new size or -1 to just adjust the offset
1421 * Set the offset and total size of the memory blocks in @buffer.
1424 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1426 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1430 * gst_buffer_set_size:
1431 * @buffer: a #GstBuffer.
1432 * @size: the new size
1434 * Set the total size of the memory blocks in @buffer.
1437 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1439 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1443 * gst_buffer_resize_range:
1444 * @buffer: a #GstBuffer.
1447 * @offset: the offset adjustment
1448 * @size: the new size or -1 to just adjust the offset
1450 * Set the total size of the @length memory blocks starting at @idx in
1453 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1456 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1457 gssize offset, gssize size)
1460 gsize bsize, bufsize, bufoffs, bufmax;
1462 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1463 g_return_val_if_fail (size >= -1, FALSE);
1465 len = GST_BUFFER_MEM_LEN (buffer);
1466 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1467 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1472 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1474 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1475 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1476 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1478 /* we can't go back further than the current offset or past the end of the
1480 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1481 && bufoffs + offset <= bufmax), FALSE);
1483 g_return_val_if_fail (bufsize >= offset, FALSE);
1484 size = bufsize - offset;
1486 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1489 if (offset == 0 && size == bufsize)
1494 for (i = idx; i < end; i++) {
1498 mem = GST_BUFFER_MEM_PTR (buffer, i);
1499 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1502 /* last buffer always gets resized to the remaining size */
1505 /* shrink buffers before the offset */
1506 else if ((gssize) bsize <= offset) {
1508 noffs = offset - bsize;
1511 /* clip other buffers */
1513 left = MIN (bsize - offset, size);
1515 if (offset != 0 || left != bsize) {
1516 if (gst_memory_is_writable (mem)) {
1517 gst_memory_resize (mem, offset, left);
1519 GstMemory *newmem = NULL;
1521 if (!GST_MEMORY_IS_NO_SHARE (mem))
1522 newmem = gst_memory_share (mem, offset, left);
1525 newmem = gst_memory_copy (mem, offset, left);
1530 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1531 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1532 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1533 gst_memory_unref (mem);
1535 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1548 * @buffer: a #GstBuffer.
1549 * @info: (out): info about the mapping
1550 * @flags: flags for the mapping
1552 * This function fills @info with the #GstMapInfo of all merged memory
1553 * blocks in @buffer.
1555 * @flags describe the desired access of the memory. When @flags is
1556 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1557 * gst_buffer_is_writable()).
1559 * When @buffer is writable but the memory isn't, a writable copy will
1560 * automatically be created and returned. The readonly copy of the
1561 * buffer memory will then also be replaced with this writable copy.
1563 * The memory in @info should be unmapped with gst_buffer_unmap() after
1566 * Returns: %TRUE if the map succeeded and @info contains valid data.
1569 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1571 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1575 * gst_buffer_map_range:
1576 * @buffer: a #GstBuffer.
1579 * @info: (out): info about the mapping
1580 * @flags: flags for the mapping
1582 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1583 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1584 * from @idx are merged and mapped.
1586 * @flags describe the desired access of the memory. When @flags is
1587 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1588 * gst_buffer_is_writable()).
1590 * When @buffer is writable but the memory isn't, a writable copy will
1591 * automatically be created and returned. The readonly copy of the buffer memory
1592 * will then also be replaced with this writable copy.
1594 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1596 * Returns: %TRUE if the map succeeded and @info contains valid
1600 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1601 GstMapInfo * info, GstMapFlags flags)
1603 GstMemory *mem, *nmem;
1604 gboolean write, writable;
1607 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1608 g_return_val_if_fail (info != NULL, FALSE);
1609 len = GST_BUFFER_MEM_LEN (buffer);
1610 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1611 (length == -1 && idx < len) || (length > 0
1612 && length + idx <= len), FALSE);
1614 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1615 buffer, idx, length, flags);
1617 write = (flags & GST_MAP_WRITE) != 0;
1618 writable = gst_buffer_is_writable (buffer);
1620 /* check if we can write when asked for write access */
1621 if (G_UNLIKELY (write && !writable))
1627 mem = _get_merged_memory (buffer, idx, length);
1628 if (G_UNLIKELY (mem == NULL))
1631 /* now try to map */
1632 nmem = gst_memory_make_mapped (mem, info, flags);
1633 if (G_UNLIKELY (nmem == NULL))
1636 /* if we merged or when the map returned a different memory, we try to replace
1637 * the memory in the buffer */
1638 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1639 /* if the buffer is writable, replace the memory */
1641 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1644 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1645 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1654 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1655 g_critical ("write map requested on non-writable buffer");
1656 memset (info, 0, sizeof (GstMapInfo));
1661 /* empty buffer, we need to return NULL */
1662 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1663 memset (info, 0, sizeof (GstMapInfo));
1668 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1669 memset (info, 0, sizeof (GstMapInfo));
1676 * @buffer: a #GstBuffer.
1677 * @info: a #GstMapInfo
1679 * Release the memory previously mapped with gst_buffer_map().
1682 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1684 g_return_if_fail (GST_IS_BUFFER (buffer));
1685 g_return_if_fail (info != NULL);
1687 /* we need to check for NULL, it is possible that we tried to map a buffer
1688 * without memory and we should be able to unmap that fine */
1689 if (G_LIKELY (info->memory)) {
1690 gst_memory_unmap (info->memory, info);
1691 gst_memory_unref (info->memory);
1697 * @buffer: a #GstBuffer.
1698 * @offset: the offset to fill
1699 * @src: (array length=size) (element-type guint8): the source address
1700 * @size: the size to fill
1702 * Copy @size bytes from @src to @buffer at @offset.
1704 * Returns: The amount of bytes copied. This value can be lower than @size
1705 * when @buffer did not contain enough data.
1708 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1712 const guint8 *ptr = src;
1714 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1715 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1716 g_return_val_if_fail (src != NULL || size == 0, 0);
1718 GST_CAT_LOG (GST_CAT_BUFFER,
1719 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1722 len = GST_BUFFER_MEM_LEN (buffer);
1725 for (i = 0; i < len && left > 0; i++) {
1730 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1731 if (info.size > offset) {
1732 /* we have enough */
1733 tocopy = MIN (info.size - offset, left);
1734 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1739 /* offset past buffer, skip */
1740 offset -= info.size;
1742 gst_memory_unmap (mem, &info);
1748 * gst_buffer_extract:
1749 * @buffer: a #GstBuffer.
1750 * @offset: the offset to extract
1751 * @dest: the destination address
1752 * @size: the size to extract
1754 * Copy @size bytes starting from @offset in @buffer to @dest.
1756 * Returns: The amount of bytes extracted. This value can be lower than @size
1757 * when @buffer did not contain enough data.
1760 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1765 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1766 g_return_val_if_fail (dest != NULL, 0);
1768 GST_CAT_LOG (GST_CAT_BUFFER,
1769 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1772 len = GST_BUFFER_MEM_LEN (buffer);
1775 for (i = 0; i < len && left > 0; i++) {
1780 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1781 if (info.size > offset) {
1782 /* we have enough */
1783 tocopy = MIN (info.size - offset, left);
1784 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1789 /* offset past buffer, skip */
1790 offset -= info.size;
1792 gst_memory_unmap (mem, &info);
1798 * gst_buffer_memcmp:
1799 * @buffer: a #GstBuffer.
1800 * @offset: the offset in @buffer
1801 * @mem: (array length=size) (element-type guint8): the memory to compare
1802 * @size: the size to compare
1804 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1806 * Returns: 0 if the memory is equal.
1809 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1813 const guint8 *ptr = mem;
1816 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1817 g_return_val_if_fail (mem != NULL, 0);
1819 GST_CAT_LOG (GST_CAT_BUFFER,
1820 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1823 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1826 len = GST_BUFFER_MEM_LEN (buffer);
1828 for (i = 0; i < len && size > 0 && res == 0; i++) {
1833 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1834 if (info.size > offset) {
1835 /* we have enough */
1836 tocmp = MIN (info.size - offset, size);
1837 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1842 /* offset past buffer, skip */
1843 offset -= info.size;
1845 gst_memory_unmap (mem, &info);
1851 * gst_buffer_memset:
1852 * @buffer: a #GstBuffer.
1853 * @offset: the offset in @buffer
1854 * @val: the value to set
1855 * @size: the size to set
1857 * Fill @buf with @size bytes with @val starting from @offset.
1859 * Returns: The amount of bytes filled. This value can be lower than @size
1860 * when @buffer did not contain enough data.
1863 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1867 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1868 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1870 GST_CAT_LOG (GST_CAT_BUFFER,
1871 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1872 buffer, offset, val, size);
1874 len = GST_BUFFER_MEM_LEN (buffer);
1877 for (i = 0; i < len && left > 0; i++) {
1882 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1883 if (info.size > offset) {
1884 /* we have enough */
1885 toset = MIN (info.size - offset, left);
1886 memset ((guint8 *) info.data + offset, val, toset);
1890 /* offset past buffer, skip */
1891 offset -= info.size;
1893 gst_memory_unmap (mem, &info);
1899 * gst_buffer_copy_region:
1900 * @parent: a #GstBuffer.
1901 * @flags: the #GstBufferCopyFlags
1902 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1904 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
1907 * Creates a sub-buffer from @parent at @offset and @size.
1908 * This sub-buffer uses the actual memory space of the parent buffer.
1909 * This function will copy the offset and timestamp fields when the
1910 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1911 * #GST_BUFFER_OFFSET_NONE.
1912 * If @offset equals 0 and @size equals the total size of @buffer, the
1913 * duration and offset end fields are also copied. If not they will be set
1914 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1918 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
1922 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1923 gsize offset, gsize size)
1927 g_return_val_if_fail (buffer != NULL, NULL);
1929 /* create the new buffer */
1930 copy = gst_buffer_new ();
1932 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1933 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1935 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1936 gst_buffer_replace (©, NULL);
1942 * gst_buffer_append:
1943 * @buf1: (transfer full): the first source #GstBuffer to append.
1944 * @buf2: (transfer full): the second source #GstBuffer to append.
1946 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1947 * concatenation of the memory of @buf1 and @buf2.
1949 * Returns: (transfer full): the new #GstBuffer that contains the memory
1950 * of the two source buffers.
1953 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1955 return gst_buffer_append_region (buf1, buf2, 0, -1);
1959 * gst_buffer_append_region:
1960 * @buf1: (transfer full): the first source #GstBuffer to append.
1961 * @buf2: (transfer full): the second source #GstBuffer to append.
1962 * @offset: the offset in @buf2
1963 * @size: the size or -1 of @buf2
1965 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1966 * contain a concatenation of the memory of @buf1 and the requested region of
1969 * Returns: (transfer full): the new #GstBuffer that contains the memory
1970 * of the two source buffers.
1973 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
1978 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1979 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1981 buf1 = gst_buffer_make_writable (buf1);
1982 buf2 = gst_buffer_make_writable (buf2);
1984 gst_buffer_resize (buf2, offset, size);
1986 len = GST_BUFFER_MEM_LEN (buf2);
1987 for (i = 0; i < len; i++) {
1990 mem = GST_BUFFER_MEM_PTR (buf2, i);
1991 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1992 _memory_add (buf1, -1, mem);
1995 GST_BUFFER_MEM_LEN (buf2) = 0;
1996 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
1997 gst_buffer_unref (buf2);
2003 * gst_buffer_get_meta:
2004 * @buffer: a #GstBuffer
2005 * @api: the #GType of an API
2007 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
2008 * returned. If multiple metadata with the given @api are attached to this
2009 * buffer only the first one is returned. To handle multiple metadata with a
2010 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
2011 * and check the meta->info.api member for the API type.
2013 * Returns: (transfer none) (nullable): the metadata for @api on
2017 gst_buffer_get_meta (GstBuffer * buffer, GType api)
2020 GstMeta *result = NULL;
2022 g_return_val_if_fail (buffer != NULL, NULL);
2023 g_return_val_if_fail (api != 0, NULL);
2025 /* find GstMeta of the requested API */
2026 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
2027 GstMeta *meta = &item->meta;
2028 if (meta->info->api == api) {
2037 * gst_buffer_add_meta:
2038 * @buffer: a #GstBuffer
2039 * @info: a #GstMetaInfo
2040 * @params: params for @info
2042 * Add metadata for @info to @buffer using the parameters in @params.
2044 * Returns: (transfer none): the metadata for the api in @info on @buffer.
2047 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2051 GstMeta *result = NULL;
2054 g_return_val_if_fail (buffer != NULL, NULL);
2055 g_return_val_if_fail (info != NULL, NULL);
2056 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2058 /* create a new slice */
2059 size = ITEM_SIZE (info);
2060 item = g_slice_alloc (size);
2061 result = &item->meta;
2062 result->info = info;
2063 result->flags = GST_META_FLAG_NONE;
2065 GST_CAT_DEBUG (GST_CAT_BUFFER,
2066 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2067 g_type_name (info->type), info->size);
2069 /* call the init_func when needed */
2070 if (info->init_func)
2071 if (!info->init_func (result, params, buffer))
2074 /* and add to the list of metadata */
2075 item->next = GST_BUFFER_META (buffer);
2076 GST_BUFFER_META (buffer) = item;
2082 g_slice_free1 (size, item);
2088 * gst_buffer_remove_meta:
2089 * @buffer: a #GstBuffer
2092 * Remove the metadata for @meta on @buffer.
2094 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2095 * metadata was on @buffer.
2098 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2100 GstMetaItem *walk, *prev;
2102 g_return_val_if_fail (buffer != NULL, FALSE);
2103 g_return_val_if_fail (meta != NULL, FALSE);
2104 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2105 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2108 /* find the metadata and delete */
2109 prev = GST_BUFFER_META (buffer);
2110 for (walk = prev; walk; walk = walk->next) {
2111 GstMeta *m = &walk->meta;
2113 const GstMetaInfo *info = meta->info;
2115 /* remove from list */
2116 if (GST_BUFFER_META (buffer) == walk)
2117 GST_BUFFER_META (buffer) = walk->next;
2119 prev->next = walk->next;
2120 /* call free_func if any */
2121 if (info->free_func)
2122 info->free_func (m, buffer);
2124 /* and free the slice */
2125 g_slice_free1 (ITEM_SIZE (info), walk);
2130 return walk != NULL;
2134 * gst_buffer_iterate_meta:
2135 * @buffer: a #GstBuffer
2136 * @state: an opaque state pointer
2138 * Retrieve the next #GstMeta after @current. If @state points
2139 * to %NULL, the first metadata is returned.
2141 * @state will be updated with an opaque state pointer
2143 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2144 * when there are no more items.
2147 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2151 g_return_val_if_fail (buffer != NULL, NULL);
2152 g_return_val_if_fail (state != NULL, NULL);
2154 meta = (GstMetaItem **) state;
2156 /* state NULL, move to first item */
2157 *meta = GST_BUFFER_META (buffer);
2159 /* state !NULL, move to next item in list */
2160 *meta = (*meta)->next;
2163 return &(*meta)->meta;
2169 * gst_buffer_foreach_meta:
2170 * @buffer: a #GstBuffer
2171 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2172 * @user_data: (closure): user data passed to @func
2174 * Call @func with @user_data for each meta in @buffer.
2176 * @func can modify the passed meta pointer or its contents. The return value
2177 * of @func define if this function returns or if the remaining metadata items
2178 * in the buffer should be skipped.
2180 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2183 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2186 GstMetaItem *walk, *prev, *next;
2187 gboolean res = TRUE;
2189 g_return_val_if_fail (buffer != NULL, FALSE);
2190 g_return_val_if_fail (func != NULL, FALSE);
2192 /* find the metadata and delete */
2193 prev = GST_BUFFER_META (buffer);
2194 for (walk = prev; walk; walk = next) {
2197 m = new = &walk->meta;
2200 res = func (buffer, &new, user_data);
2203 const GstMetaInfo *info = m->info;
2205 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2206 g_type_name (info->type));
2208 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2209 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2212 /* remove from list */
2213 if (GST_BUFFER_META (buffer) == walk)
2214 GST_BUFFER_META (buffer) = next;
2218 /* call free_func if any */
2219 if (info->free_func)
2220 info->free_func (m, buffer);
2222 /* and free the slice */
2223 g_slice_free1 (ITEM_SIZE (info), walk);
2232 * gst_buffer_extract_dup:
2233 * @buffer: a #GstBuffer
2234 * @offset: the offset to extract
2235 * @size: the size to extract
2236 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2237 * the destination array will be written.
2238 * @dest_size: (out): A location where the size of @dest can be written
2240 * Extracts a copy of at most @size bytes the data at @offset into a #GBytes.
2241 * @dest must be freed using g_free() when done.
2247 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2248 gpointer * dest, gsize * dest_size)
2252 real_size = gst_buffer_get_size (buffer);
2254 *dest = g_malloc (MIN (real_size - offset, size));
2256 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);