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.
26 * @short_description: Data-passing buffer type
27 * @see_also: #GstPad, #GstMiniObject, #GstMemory, #GstMeta, #GstBufferPool
29 * Buffers are the basic unit of data transfer in GStreamer. They contain the
30 * timing and offset along with other arbitrary metadata that is associated
31 * with the #GstMemory blocks that the buffer contains.
33 * Buffers are usually created with gst_buffer_new(). After a buffer has been
34 * created one will typically allocate memory for it and add it to the buffer.
35 * The following example creates a buffer that can hold a given video frame
36 * with a given width, height and bits per plane.
37 * |[<!-- language="C" -->
40 * gint size, width, height, bpp;
42 * size = width * height * bpp;
43 * buffer = gst_buffer_new ();
44 * memory = gst_allocator_alloc (NULL, size, NULL);
45 * gst_buffer_insert_memory (buffer, -1, memory);
49 * Alternatively, use gst_buffer_new_allocate() to create a buffer with
50 * preallocated data of a given size.
52 * Buffers can contain a list of #GstMemory objects. You can retrieve how many
53 * memory objects with gst_buffer_n_memory() and you can get a pointer
54 * to memory with gst_buffer_peek_memory()
56 * A buffer will usually have timestamps, and a duration, but neither of these
57 * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
58 * meaningful value can be given for these, they should be set. The timestamps
59 * and duration are measured in nanoseconds (they are #GstClockTime values).
61 * The buffer DTS refers to the timestamp when the buffer should be decoded and
62 * is usually monotonically increasing. The buffer PTS refers to the timestamp when
63 * the buffer content should be presented to the user and is not always
64 * monotonically increasing.
66 * A buffer can also have one or both of a start and an end offset. These are
67 * media-type specific. For video buffers, the start offset will generally be
68 * the frame number. For audio buffers, it will be the number of samples
69 * produced so far. For compressed data, it could be the byte offset in a
70 * source or destination file. Likewise, the end offset will be the offset of
71 * the end of the buffer. These can only be meaningfully interpreted if you
72 * know the media type of the buffer (the preceding CAPS event). Either or both
73 * can be set to #GST_BUFFER_OFFSET_NONE.
75 * gst_buffer_ref() is used to increase the refcount of a buffer. This must be
76 * done when you want to keep a handle to the buffer after pushing it to the
77 * next element. The buffer refcount determines the writability of the buffer, a
78 * buffer is only writable when the refcount is exactly 1, i.e. when the caller
79 * has the only reference to the buffer.
81 * To efficiently create a smaller buffer out of an existing one, you can
82 * use gst_buffer_copy_region(). This method tries to share the memory objects
83 * between the two buffers.
85 * If a plug-in wants to modify the buffer data or metadata in-place, it should
86 * first obtain a buffer that is safe to modify by using
87 * gst_buffer_make_writable(). This function is optimized so that a copy will
88 * only be made when it is necessary.
90 * Several flags of the buffer can be set and unset with the
91 * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
92 * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlags flag is set.
94 * Buffers can be efficiently merged into a larger buffer with
95 * gst_buffer_append(). Copying of memory will only be done when absolutely
98 * Arbitrary extra metadata can be set on a buffer with gst_buffer_add_meta().
99 * Metadata can be retrieved with gst_buffer_get_meta(). See also #GstMeta
101 * An element should either unref the buffer or push it out on a src pad
102 * using gst_pad_push() (see #GstPad).
104 * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
105 * the refcount drops to 0, any memory and metadata pointed to by the buffer is
106 * unreffed as well. Buffers allocated from a #GstBufferPool will be returned to
107 * the pool when the refcount drops to 0.
109 * The #GstParentBufferMeta is a meta which can be attached to a #GstBuffer
110 * to hold a reference to another buffer that is only released when the child
111 * #GstBuffer is released.
113 * Typically, #GstParentBufferMeta is used when the child buffer is directly
114 * using the #GstMemory of the parent buffer, and wants to prevent the parent
115 * buffer from being returned to a buffer pool until the #GstMemory is available
116 * for re-use. (Since: 1.6)
119 #include "gst_private.h"
128 #include "gstbuffer.h"
129 #include "gstbufferpool.h"
131 #include "gstutils.h"
132 #include "gstversion.h"
134 GType _gst_buffer_type = 0;
136 /* info->size will be sizeof(FooMeta) which contains a GstMeta at the beginning
137 * too, and then there is again a GstMeta in GstMetaItem, so subtract one. */
138 #define ITEM_SIZE(info) ((info)->size + sizeof (GstMetaItem) - sizeof (GstMeta))
140 #define GST_BUFFER_MEM_MAX 16
142 #define GST_BUFFER_SLICE_SIZE(b) (((GstBufferImpl *)(b))->slice_size)
143 #define GST_BUFFER_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
144 #define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
145 #define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
146 #define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
147 #define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
148 #define GST_BUFFER_TAIL_META(b) (((GstBufferImpl *)(b))->tail_item)
156 /* the memory blocks */
158 GstMemory *mem[GST_BUFFER_MEM_MAX];
160 /* memory of the buffer when allocated from 1 chunk */
163 /* FIXME, make metadata allocation more efficient by using part of the
166 GstMetaItem *tail_item;
169 static gint64 meta_seq; /* 0 *//* ATOMIC */
171 /* TODO: use GLib's once https://gitlab.gnome.org/GNOME/glib/issues/1076 lands */
172 #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8)
174 gst_atomic_int64_inc (volatile gint64 * atomic)
176 return __sync_fetch_and_add (atomic, 1);
178 #elif defined (G_PLATFORM_WIN32)
181 gst_atomic_int64_inc (volatile gint64 * atomic)
183 return InterlockedExchangeAdd64 (atomic, 1);
186 #warning No 64-bit atomic int defined for this platform/toolchain!
187 #define NO_64BIT_ATOMIC_INT_FOR_PLATFORM
188 G_LOCK_DEFINE_STATIC (meta_seq);
190 gst_atomic_int64_inc (volatile gint64 * atomic)
203 _is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
205 GstMemory *mcur, *mprv;
206 gboolean have_offset = FALSE;
211 for (i = 0; i < len; i++) {
219 /* check if memory is contiguous */
220 if (!gst_memory_is_span (mprv, mcur, &poffs))
227 *parent = mprv->parent;
237 _get_merged_memory (GstBuffer * buffer, guint idx, guint length)
239 GstMemory **mem, *result = NULL;
241 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %u", buffer, idx,
244 mem = GST_BUFFER_MEM_ARRAY (buffer);
246 if (G_UNLIKELY (length == 0)) {
248 } else if (G_LIKELY (length == 1)) {
249 result = gst_memory_ref (mem[idx]);
251 GstMemory *parent = NULL;
252 gsize size, poffset = 0;
254 size = gst_buffer_get_sizes_range (buffer, idx, length, NULL, NULL);
256 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
257 if (!GST_MEMORY_IS_NO_SHARE (parent))
258 result = gst_memory_share (parent, poffset, size);
260 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
261 result = gst_memory_copy (parent, poffset, size);
264 gsize i, tocopy, left;
265 GstMapInfo sinfo, dinfo;
268 result = gst_allocator_alloc (NULL, size, NULL);
269 if (result == NULL || !gst_memory_map (result, &dinfo, GST_MAP_WRITE)) {
270 GST_CAT_ERROR (GST_CAT_BUFFER, "Failed to map memory writable");
272 gst_memory_unref (result);
279 for (i = idx; i < (idx + length) && left > 0; i++) {
280 if (!gst_memory_map (mem[i], &sinfo, GST_MAP_READ)) {
281 GST_CAT_ERROR (GST_CAT_BUFFER,
282 "buffer %p, idx %u, length %u failed to map readable", buffer,
284 gst_memory_unmap (result, &dinfo);
285 gst_memory_unref (result);
288 tocopy = MIN (sinfo.size, left);
289 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
290 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
291 tocopy, result, mem[i]);
292 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
295 gst_memory_unmap (mem[i], &sinfo);
297 gst_memory_unmap (result, &dinfo);
304 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
311 GST_CAT_LOG (GST_CAT_BUFFER,
312 "buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
315 /* unref old memory */
316 for (i = idx; i < end; i++) {
317 GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
319 gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
320 gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (old),
321 GST_MINI_OBJECT_CAST (buffer));
322 gst_memory_unref (old);
326 /* replace with single memory */
327 gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (mem),
328 GST_MINI_OBJECT_CAST (buffer));
329 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
330 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
336 memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
337 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
339 GST_BUFFER_MEM_LEN (buffer) = len - length;
340 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
344 * gst_buffer_get_flags:
345 * @buffer: a #GstBuffer
347 * Get the #GstBufferFlags flags set on this buffer.
349 * Returns: the flags set on this buffer.
354 gst_buffer_get_flags (GstBuffer * buffer)
356 return (GstBufferFlags) GST_BUFFER_FLAGS (buffer);
360 * gst_buffer_flag_is_set:
361 * @buffer: a #GstBuffer
362 * @flags: the #GstBufferFlags flag to check.
364 * Gives the status of a specific flag on a buffer.
366 * Returns: %TRUE if all flags in @flags are found on @buffer.
371 gst_buffer_has_flags (GstBuffer * buffer, GstBufferFlags flags)
373 return GST_BUFFER_FLAG_IS_SET (buffer, flags);
377 * gst_buffer_set_flags:
378 * @buffer: a #GstBuffer
379 * @flags: the #GstBufferFlags to set.
381 * Sets one or more buffer flags on a buffer.
383 * Returns: %TRUE if @flags were successfully set on buffer.
388 gst_buffer_set_flags (GstBuffer * buffer, GstBufferFlags flags)
390 GST_BUFFER_FLAG_SET (buffer, flags);
395 * gst_buffer_unset_flags:
396 * @buffer: a #GstBuffer
397 * @flags: the #GstBufferFlags to clear
399 * Clears one or more buffer flags.
401 * Returns: true if @flags is successfully cleared from buffer.
406 gst_buffer_unset_flags (GstBuffer * buffer, GstBufferFlags flags)
408 GST_BUFFER_FLAG_UNSET (buffer, flags);
414 /* transfer full for return and transfer none for @mem */
415 static inline GstMemory *
416 _memory_get_exclusive_reference (GstMemory * mem)
418 GstMemory *ret = NULL;
420 if (gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE)) {
421 ret = gst_memory_ref (mem);
423 /* we cannot take another exclusive lock as the memory is already
424 * locked WRITE + EXCLUSIVE according to part-miniobject.txt */
425 ret = gst_memory_copy (mem, 0, -1);
428 if (!gst_memory_lock (ret, GST_LOCK_FLAG_EXCLUSIVE)) {
429 gst_memory_unref (ret);
436 GST_CAT_WARNING (GST_CAT_BUFFER, "Failed to acquire an exclusive lock for "
443 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem)
445 guint i, len = GST_BUFFER_MEM_LEN (buffer);
447 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p", buffer, idx, mem);
449 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
450 /* too many buffer, span them. */
451 /* FIXME, there is room for improvement here: We could only try to merge
452 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
453 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
454 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
456 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
457 /* we now have 1 single spanned buffer */
464 for (i = len; i > idx; i--) {
465 /* move buffers to insert, FIXME, we need to insert first and then merge */
466 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
468 /* and insert the new buffer */
469 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
470 GST_BUFFER_MEM_LEN (buffer) = len + 1;
471 gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (mem),
472 GST_MINI_OBJECT_CAST (buffer));
474 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
477 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
480 _priv_gst_buffer_initialize (void)
482 _gst_buffer_type = gst_buffer_get_type ();
484 #ifdef NO_64BIT_ATOMIC_INT_FOR_PLATFORM
485 GST_CAT_WARNING (GST_CAT_PERFORMANCE,
486 "No 64-bit atomic int defined for this platform/toolchain!");
491 * gst_buffer_get_max_memory:
493 * Get the maximum amount of memory blocks that a buffer can hold. This is a
494 * compile time constant that can be queried with the function.
496 * When more memory blocks are added, existing memory blocks will be merged
497 * together to make room for the new block.
499 * Returns: the maximum amount of memory blocks that a buffer can hold.
504 gst_buffer_get_max_memory (void)
506 return GST_BUFFER_MEM_MAX;
510 * gst_buffer_copy_into:
511 * @dest: a destination #GstBuffer
512 * @src: a source #GstBuffer
513 * @flags: flags indicating what metadata fields should be copied.
514 * @offset: offset to copy from
515 * @size: total size to copy. If -1, all data is copied.
517 * Copies the information from @src into @dest.
519 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
520 * the memory from @src will be appended to @dest.
522 * @flags indicate which fields will be copied.
524 * Returns: %TRUE if the copying succeeded, %FALSE otherwise.
527 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
528 GstBufferCopyFlags flags, gsize offset, gsize size)
532 gboolean region = FALSE;
534 g_return_val_if_fail (dest != NULL, FALSE);
535 g_return_val_if_fail (src != NULL, FALSE);
537 /* nothing to copy if the buffers are the same */
538 if (G_UNLIKELY (dest == src))
541 g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
543 bufsize = gst_buffer_get_size (src);
544 g_return_val_if_fail (bufsize >= offset, FALSE);
548 size = bufsize - offset;
551 g_return_val_if_fail (bufsize >= offset + size, FALSE);
553 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
554 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
557 if (flags & GST_BUFFER_COPY_FLAGS) {
559 guint flags_mask = ~GST_BUFFER_FLAG_TAG_MEMORY;
561 GST_MINI_OBJECT_FLAGS (dest) =
562 (GST_MINI_OBJECT_FLAGS (src) & flags_mask) |
563 (GST_MINI_OBJECT_FLAGS (dest) & ~flags_mask);
566 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
568 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
569 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
570 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
571 if (size == bufsize) {
572 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
573 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
576 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
577 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
578 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
579 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
580 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
584 if (flags & GST_BUFFER_COPY_MEMORY) {
585 gsize skip, left, len, dest_len, i, bsize;
588 deep = flags & GST_BUFFER_COPY_DEEP;
590 len = GST_BUFFER_MEM_LEN (src);
591 dest_len = GST_BUFFER_MEM_LEN (dest);
595 /* copy and make regions of the memory */
596 for (i = 0; i < len && left > 0; i++) {
597 GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
599 bsize = gst_memory_get_sizes (mem, NULL, NULL);
602 /* don't copy buffer */
605 GstMemory *newmem = NULL;
608 tocopy = MIN (bsize - skip, left);
610 if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
611 /* we need to clip something */
612 newmem = gst_memory_share (mem, skip, tocopy);
614 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
619 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
620 /* deep copy or we're not allowed to share this memory
621 * between buffers, always copy then */
622 newmem = gst_memory_copy (mem, skip, tocopy);
624 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
627 } else if (!newmem) {
628 newmem = _memory_get_exclusive_reference (mem);
632 gst_buffer_remove_memory_range (dest, dest_len, -1);
636 _memory_add (dest, -1, newmem);
640 if (flags & GST_BUFFER_COPY_MERGE) {
643 len = GST_BUFFER_MEM_LEN (dest);
644 mem = _get_merged_memory (dest, 0, len);
646 gst_buffer_remove_memory_range (dest, dest_len, -1);
649 _replace_memory (dest, len, 0, len, mem);
653 if (flags & GST_BUFFER_COPY_META) {
654 /* NOTE: GstGLSyncMeta copying relies on the meta
655 * being copied now, after the buffer data,
656 * so this has to happen last */
657 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
658 GstMeta *meta = &walk->meta;
659 const GstMetaInfo *info = meta->info;
661 /* Don't copy memory metas if we only copied part of the buffer, didn't
662 * copy memories or merged memories. In all these cases the memory
663 * structure has changed and the memory meta becomes meaningless.
665 if ((region || !(flags & GST_BUFFER_COPY_MEMORY)
666 || (flags & GST_BUFFER_COPY_MERGE))
667 && gst_meta_api_type_has_tag (info->api, _gst_meta_tag_memory)) {
668 GST_CAT_DEBUG (GST_CAT_BUFFER,
669 "don't copy memory meta %p of API type %s", meta,
670 g_type_name (info->api));
671 } else if (info->transform_func) {
672 GstMetaTransformCopy copy_data;
674 copy_data.region = region;
675 copy_data.offset = offset;
676 copy_data.size = size;
678 if (!info->transform_func (dest, meta, src,
679 _gst_meta_transform_copy, ©_data)) {
680 GST_CAT_ERROR (GST_CAT_BUFFER,
681 "failed to copy meta %p of API type %s", meta,
682 g_type_name (info->api));
692 gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
696 g_return_val_if_fail (buffer != NULL, NULL);
698 /* create a fresh new buffer */
699 copy = gst_buffer_new ();
701 /* copy what the 'flags' want from our parent */
702 /* FIXME why we can't pass const to gst_buffer_copy_into() ? */
703 if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
704 gst_buffer_replace (©, NULL);
707 GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
713 _gst_buffer_copy (const GstBuffer * buffer)
715 return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
719 * gst_buffer_copy_deep:
720 * @buf: a #GstBuffer.
722 * Create a copy of the given buffer. This will make a newly allocated
723 * copy of the data the source buffer contains.
725 * Returns: (transfer full): a new copy of @buf.
730 gst_buffer_copy_deep (const GstBuffer * buffer)
732 return gst_buffer_copy_with_flags (buffer,
733 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
736 /* the default dispose function revives the buffer and returns it to the
737 * pool when there is a pool */
739 _gst_buffer_dispose (GstBuffer * buffer)
743 /* no pool, do free */
744 if ((pool = buffer->pool) == NULL)
747 /* keep the buffer alive */
748 gst_buffer_ref (buffer);
749 /* return the buffer to the pool */
750 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
751 gst_buffer_pool_release_buffer (pool, buffer);
757 _gst_buffer_free (GstBuffer * buffer)
759 GstMetaItem *walk, *next;
763 g_return_if_fail (buffer != NULL);
765 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
768 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
769 GstMeta *meta = &walk->meta;
770 const GstMetaInfo *info = meta->info;
772 /* call free_func if any */
774 info->free_func (meta, buffer);
777 /* and free the slice */
778 g_slice_free1 (ITEM_SIZE (info), walk);
781 /* get the size, when unreffing the memory, we could also unref the buffer
783 msize = GST_BUFFER_SLICE_SIZE (buffer);
785 /* free our memory */
786 len = GST_BUFFER_MEM_LEN (buffer);
787 for (i = 0; i < len; i++) {
788 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
789 gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (GST_BUFFER_MEM_PTR
790 (buffer, i)), GST_MINI_OBJECT_CAST (buffer));
791 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
794 /* we set msize to 0 when the buffer is part of the memory block */
797 memset (buffer, 0xff, msize);
799 g_slice_free1 (msize, buffer);
801 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
806 gst_buffer_init (GstBufferImpl * buffer, gsize size)
808 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
809 (GstMiniObjectCopyFunction) _gst_buffer_copy,
810 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
811 (GstMiniObjectFreeFunction) _gst_buffer_free);
813 GST_BUFFER_SLICE_SIZE (buffer) = size;
815 GST_BUFFER (buffer)->pool = NULL;
816 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
817 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
818 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
819 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
820 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
822 GST_BUFFER_MEM_LEN (buffer) = 0;
823 GST_BUFFER_META (buffer) = NULL;
829 * Creates a newly allocated buffer without any data.
833 * Returns: (transfer full): the new #GstBuffer.
836 gst_buffer_new (void)
838 GstBufferImpl *newbuf;
840 newbuf = g_slice_new (GstBufferImpl);
841 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
843 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
845 return GST_BUFFER_CAST (newbuf);
849 * gst_buffer_new_allocate:
850 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
852 * @size: the size in bytes of the new buffer's data.
853 * @params: (transfer none) (allow-none): optional parameters
855 * Tries to create a newly allocated buffer with data of the given size and
856 * extra parameters from @allocator. If the requested amount of memory can't be
857 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
859 * When @allocator is %NULL, the default memory allocator will be used.
861 * Note that when @size == 0, the buffer will not have memory associated with it.
865 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
866 * the memory couldn't be allocated.
869 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
870 GstAllocationParams * params)
881 mem = gst_allocator_alloc (allocator, size, params);
882 if (G_UNLIKELY (mem == NULL))
888 newbuf = gst_buffer_new ();
891 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
892 _memory_add (newbuf, -1, mem);
895 GST_CAT_LOG (GST_CAT_BUFFER,
896 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
901 asize = sizeof (GstBufferImpl) + size;
902 data = g_slice_alloc (asize);
903 if (G_UNLIKELY (data == NULL))
906 newbuf = GST_BUFFER_CAST (data);
908 gst_buffer_init ((GstBufferImpl *) data, asize);
910 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
912 _memory_add (newbuf, -1, mem, TRUE);
917 /* allocate memory and buffer, it might be interesting to do this but there
918 * are many complications. We need to keep the memory mapped to access the
919 * buffer fields and the memory for the buffer might be just very slow. We
920 * also need to do some more magic to get the alignment right. */
921 asize = sizeof (GstBufferImpl) + size;
922 mem = gst_allocator_alloc (allocator, asize, align);
923 if (G_UNLIKELY (mem == NULL))
926 /* map the data part and init the buffer in it, set the buffer size to 0 so
927 * that a finalize won't free the buffer */
928 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
929 gst_buffer_init ((GstBufferImpl *) data, 0);
930 gst_memory_unmap (mem);
932 /* strip off the buffer */
933 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
935 newbuf = GST_BUFFER_CAST (data);
936 GST_BUFFER_BUFMEM (newbuf) = mem;
939 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
941 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
948 GST_CAT_WARNING (GST_CAT_BUFFER,
949 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
955 * gst_buffer_new_wrapped_full:
956 * @flags: #GstMemoryFlags
957 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
958 * @maxsize: allocated size of @data
959 * @offset: offset in @data
960 * @size: size of valid data
961 * @user_data: (allow-none): user_data
962 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
964 * Allocate a new buffer that wraps the given memory. @data must point to
965 * @maxsize of memory, the wrapped buffer will have the region from @offset and
968 * When the buffer is destroyed, @notify will be called with @user_data.
970 * The prefix/padding must be filled with 0 if @flags contains
971 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
973 * Returns: (transfer full): a new #GstBuffer
976 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
977 gsize maxsize, gsize offset, gsize size, gpointer user_data,
978 GDestroyNotify notify)
983 newbuf = gst_buffer_new ();
985 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
987 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
988 _memory_add (newbuf, -1, mem);
989 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
995 * gst_buffer_new_wrapped:
996 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
997 * @size: allocated size of @data
999 * Creates a new buffer that wraps the given @data. The memory will be freed
1000 * with g_free and will be marked writable.
1004 * Returns: (transfer full): a new #GstBuffer
1007 gst_buffer_new_wrapped (gpointer data, gsize size)
1009 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
1013 * gst_buffer_new_wrapped_bytes:
1014 * @bytes: (transfer none): a #GBytes to wrap
1016 * Creates a new #GstBuffer that wraps the given @bytes. The data inside
1017 * @bytes cannot be %NULL and the resulting buffer will be marked as read only.
1021 * Returns: (transfer full): a new #GstBuffer wrapping @bytes
1026 gst_buffer_new_wrapped_bytes (GBytes * bytes)
1031 g_return_val_if_fail (bytes != NULL, NULL);
1032 bytes_data = (guint8 *) g_bytes_get_data (bytes, &size);
1033 g_return_val_if_fail (bytes_data != NULL, NULL);
1035 return gst_buffer_new_wrapped_full (GST_MEMORY_FLAG_READONLY, bytes_data,
1036 size, 0, size, g_bytes_ref (bytes), (GDestroyNotify) g_bytes_unref);
1040 * gst_buffer_n_memory:
1041 * @buffer: a #GstBuffer.
1043 * Get the amount of memory blocks that this buffer has. This amount is never
1044 * larger than what gst_buffer_get_max_memory() returns.
1046 * Returns: the number of memory blocks this buffer is made of.
1049 gst_buffer_n_memory (GstBuffer * buffer)
1051 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1053 return GST_BUFFER_MEM_LEN (buffer);
1057 * gst_buffer_prepend_memory:
1058 * @buffer: a #GstBuffer.
1059 * @mem: (transfer full): a #GstMemory.
1061 * Prepend the memory block @mem to @buffer. This function takes
1062 * ownership of @mem and thus doesn't increase its refcount.
1064 * This function is identical to gst_buffer_insert_memory() with an index of 0.
1065 * See gst_buffer_insert_memory() for more details.
1068 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
1070 gst_buffer_insert_memory (buffer, 0, mem);
1074 * gst_buffer_append_memory:
1075 * @buffer: a #GstBuffer.
1076 * @mem: (transfer full): a #GstMemory.
1078 * Append the memory block @mem to @buffer. This function takes
1079 * ownership of @mem and thus doesn't increase its refcount.
1081 * This function is identical to gst_buffer_insert_memory() with an index of -1.
1082 * See gst_buffer_insert_memory() for more details.
1085 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
1087 gst_buffer_insert_memory (buffer, -1, mem);
1091 * gst_buffer_insert_memory:
1092 * @buffer: a #GstBuffer.
1093 * @idx: the index to add the memory at, or -1 to append it to the end
1094 * @mem: (transfer full): a #GstMemory.
1096 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
1097 * of @mem and thus doesn't increase its refcount.
1099 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
1100 * added, existing memory blocks will automatically be merged to make room for
1104 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
1108 g_return_if_fail (GST_IS_BUFFER (buffer));
1109 g_return_if_fail (gst_buffer_is_writable (buffer));
1110 g_return_if_fail (mem != NULL);
1111 g_return_if_fail (idx == -1 ||
1112 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
1114 tmp = _memory_get_exclusive_reference (mem);
1115 g_return_if_fail (tmp != NULL);
1116 gst_memory_unref (mem);
1117 _memory_add (buffer, idx, tmp);
1121 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
1124 GstMemory *mem, *mapped;
1126 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
1128 mapped = gst_memory_make_mapped (mem, info, flags);
1130 if (mapped != mem) {
1131 /* memory changed, lock new memory */
1132 gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (mapped),
1133 GST_MINI_OBJECT_CAST (buffer));
1134 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
1135 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
1136 /* unlock old memory */
1137 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1138 gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (mem),
1139 GST_MINI_OBJECT_CAST (buffer));
1140 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1142 gst_memory_unref (mem);
1148 * gst_buffer_peek_memory:
1149 * @buffer: a #GstBuffer.
1152 * Get the memory block at @idx in @buffer. The memory block stays valid until
1153 * the memory block in @buffer is removed, replaced or merged, typically with
1154 * any call that modifies the memory in @buffer.
1156 * Returns: (transfer none) (nullable): the #GstMemory at @idx.
1159 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
1163 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1164 len = GST_BUFFER_MEM_LEN (buffer);
1165 g_return_val_if_fail (idx < len, NULL);
1167 return GST_BUFFER_MEM_PTR (buffer, idx);
1171 * gst_buffer_get_memory:
1172 * @buffer: a #GstBuffer.
1175 * Get the memory block at index @idx in @buffer.
1177 * Returns: (transfer full) (nullable): a #GstMemory that contains the data of the
1178 * memory block at @idx. Use gst_memory_unref () after usage.
1181 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
1183 return gst_buffer_get_memory_range (buffer, idx, 1);
1187 * gst_buffer_get_all_memory:
1188 * @buffer: a #GstBuffer.
1190 * Get all the memory block in @buffer. The memory blocks will be merged
1191 * into one large #GstMemory.
1193 * Returns: (transfer full) (nullable): a #GstMemory that contains the merged memory.
1194 * Use gst_memory_unref () after usage.
1197 gst_buffer_get_all_memory (GstBuffer * buffer)
1199 return gst_buffer_get_memory_range (buffer, 0, -1);
1203 * gst_buffer_get_memory_range:
1204 * @buffer: a #GstBuffer.
1208 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
1209 * be merged into one large #GstMemory.
1211 * If @length is -1, all memory starting from @idx is merged.
1213 * Returns: (transfer full) (nullable): a #GstMemory that contains the merged data of @length
1214 * blocks starting at @idx. Use gst_memory_unref () after usage.
1217 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1221 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1223 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1224 len = GST_BUFFER_MEM_LEN (buffer);
1225 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1226 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1231 return _get_merged_memory (buffer, idx, length);
1235 * gst_buffer_replace_memory:
1236 * @buffer: a #GstBuffer.
1238 * @mem: (transfer full): a #GstMemory
1240 * Replaces the memory block at index @idx in @buffer with @mem.
1243 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1245 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1249 * gst_buffer_replace_all_memory:
1250 * @buffer: a #GstBuffer.
1251 * @mem: (transfer full): a #GstMemory
1253 * Replaces all memory in @buffer with @mem.
1256 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1258 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1262 * gst_buffer_replace_memory_range:
1263 * @buffer: a #GstBuffer.
1265 * @length: a length should not be 0
1266 * @mem: (transfer full): a #GstMemory
1268 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1270 * If @length is -1, all memory starting from @idx will be removed and
1271 * replaced with @mem.
1273 * @buffer should be writable.
1276 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1281 g_return_if_fail (GST_IS_BUFFER (buffer));
1282 g_return_if_fail (gst_buffer_is_writable (buffer));
1284 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1286 len = GST_BUFFER_MEM_LEN (buffer);
1287 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1288 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1293 _replace_memory (buffer, len, idx, length, mem);
1297 * gst_buffer_remove_memory:
1298 * @buffer: a #GstBuffer.
1301 * Remove the memory block in @b at index @i.
1304 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1306 gst_buffer_remove_memory_range (buffer, idx, 1);
1310 * gst_buffer_remove_all_memory:
1311 * @buffer: a #GstBuffer.
1313 * Remove all the memory blocks in @buffer.
1316 gst_buffer_remove_all_memory (GstBuffer * buffer)
1318 gst_buffer_remove_memory_range (buffer, 0, -1);
1322 * gst_buffer_remove_memory_range:
1323 * @buffer: a #GstBuffer.
1327 * Remove @length memory blocks in @buffer starting from @idx.
1329 * @length can be -1, in which case all memory starting from @idx is removed.
1332 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1336 g_return_if_fail (GST_IS_BUFFER (buffer));
1337 g_return_if_fail (gst_buffer_is_writable (buffer));
1339 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1341 len = GST_BUFFER_MEM_LEN (buffer);
1342 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1343 (length == -1 && idx < len) || length + idx <= len);
1348 _replace_memory (buffer, len, idx, length, NULL);
1352 * gst_buffer_find_memory:
1353 * @buffer: a #GstBuffer.
1354 * @offset: an offset
1356 * @idx: (out): pointer to index
1357 * @length: (out): pointer to length
1358 * @skip: (out): pointer to skip
1360 * Find the memory blocks that span @size bytes starting from @offset
1363 * When this function returns %TRUE, @idx will contain the index of the first
1364 * memory block where the byte for @offset can be found and @length contains the
1365 * number of memory blocks containing the @size remaining bytes. @skip contains
1366 * the number of bytes to skip in the memory block at @idx to get to the byte
1369 * @size can be -1 to get all the memory blocks after @idx.
1371 * Returns: %TRUE when @size bytes starting from @offset could be found in
1372 * @buffer and @idx, @length and @skip will be filled.
1375 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1376 guint * idx, guint * length, gsize * skip)
1378 guint i, len, found;
1380 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1381 g_return_val_if_fail (idx != NULL, FALSE);
1382 g_return_val_if_fail (length != NULL, FALSE);
1383 g_return_val_if_fail (skip != NULL, FALSE);
1385 len = GST_BUFFER_MEM_LEN (buffer);
1388 for (i = 0; i < len; i++) {
1392 mem = GST_BUFFER_MEM_PTR (buffer, i);
1393 s = gst_memory_get_sizes (mem, NULL, NULL);
1396 /* block before offset, or empty block, skip */
1399 /* block after offset */
1401 /* first block, remember index and offset */
1405 /* return remaining blocks */
1412 /* count the amount of found bytes */
1414 if (found >= size) {
1415 /* we have enough bytes */
1416 *length = i - *idx + 1;
1425 * gst_buffer_is_memory_range_writable:
1426 * @buffer: a #GstBuffer.
1428 * @length: a length should not be 0
1430 * Check if @length memory blocks in @buffer starting from @idx are writable.
1432 * @length can be -1 to check all the memory blocks after @idx.
1434 * Note that this function does not check if @buffer is writable, use
1435 * gst_buffer_is_writable() to check that if needed.
1437 * Returns: %TRUE if the memory range is writable
1442 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1446 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1448 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1450 len = GST_BUFFER_MEM_LEN (buffer);
1451 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1452 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1460 for (i = 0; i < len; i++) {
1461 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1468 * gst_buffer_is_all_memory_writable:
1469 * @buffer: a #GstBuffer.
1471 * Check if all memory blocks in @buffer are writable.
1473 * Note that this function does not check if @buffer is writable, use
1474 * gst_buffer_is_writable() to check that if needed.
1476 * Returns: %TRUE if all memory blocks in @buffer are writable
1481 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1483 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1487 * gst_buffer_get_sizes:
1488 * @buffer: a #GstBuffer.
1489 * @offset: (out) (allow-none): a pointer to the offset
1490 * @maxsize: (out) (allow-none): a pointer to the maxsize
1492 * Get the total size of the memory blocks in @b.
1494 * When not %NULL, @offset will contain the offset of the data in the
1495 * first memory block in @buffer and @maxsize will contain the sum of
1496 * the size and @offset and the amount of extra padding on the last
1497 * memory block. @offset and @maxsize can be used to resize the
1498 * buffer memory blocks with gst_buffer_resize().
1500 * Returns: total size of the memory blocks in @buffer.
1503 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1505 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1509 * gst_buffer_get_size:
1510 * @buffer: a #GstBuffer.
1512 * Get the total size of the memory blocks in @buffer.
1514 * Returns: total size of the memory blocks in @buffer.
1517 gst_buffer_get_size (GstBuffer * buffer)
1519 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1523 * gst_buffer_get_sizes_range:
1524 * @buffer: a #GstBuffer.
1527 * @offset: (out) (allow-none): a pointer to the offset
1528 * @maxsize: (out) (allow-none): a pointer to the maxsize
1530 * Get the total size of @length memory blocks stating from @idx in @buffer.
1532 * When not %NULL, @offset will contain the offset of the data in the
1533 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1534 * and @offset and the amount of extra padding on the memory block at @idx +
1536 * @offset and @maxsize can be used to resize the buffer memory blocks with
1537 * gst_buffer_resize_range().
1539 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1542 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1543 gsize * offset, gsize * maxsize)
1549 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1550 len = GST_BUFFER_MEM_LEN (buffer);
1551 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1552 (length == -1 && idx < len) || (length + idx <= len), 0);
1557 if (G_LIKELY (length == 1)) {
1559 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1560 size = gst_memory_get_sizes (mem, offset, maxsize);
1566 size = offs = extra = 0;
1567 for (i = idx; i < end; i++) {
1570 mem = GST_BUFFER_MEM_PTR (buffer, i);
1571 s = gst_memory_get_sizes (mem, &o, &ms);
1575 /* first size, take accumulated data before as the offset */
1579 /* save the amount of data after this block */
1580 extra = ms - (o + s);
1582 /* empty block, add as extra */
1589 *maxsize = offs + size + extra;
1595 * gst_buffer_resize:
1596 * @buffer: a #GstBuffer.
1597 * @offset: the offset adjustment
1598 * @size: the new size or -1 to just adjust the offset
1600 * Set the offset and total size of the memory blocks in @buffer.
1603 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1605 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1609 * gst_buffer_set_size:
1610 * @buffer: a #GstBuffer.
1611 * @size: the new size
1613 * Set the total size of the memory blocks in @buffer.
1616 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1618 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1622 * gst_buffer_resize_range:
1623 * @buffer: a #GstBuffer.
1626 * @offset: the offset adjustment
1627 * @size: the new size or -1 to just adjust the offset
1629 * Set the total size of the @length memory blocks starting at @idx in
1632 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1635 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1636 gssize offset, gssize size)
1639 gsize bsize, bufsize, bufoffs, bufmax;
1641 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1642 g_return_val_if_fail (size >= -1, FALSE);
1644 len = GST_BUFFER_MEM_LEN (buffer);
1645 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1646 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1651 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1653 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1654 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1655 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1657 /* we can't go back further than the current offset or past the end of the
1659 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1660 && bufoffs + offset <= bufmax), FALSE);
1662 g_return_val_if_fail (bufsize >= offset, FALSE);
1663 size = bufsize - offset;
1665 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1668 if (offset == 0 && size == bufsize)
1673 for (i = idx; i < end; i++) {
1677 mem = GST_BUFFER_MEM_PTR (buffer, i);
1678 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1681 /* last buffer always gets resized to the remaining size */
1684 /* shrink buffers before the offset */
1685 else if ((gssize) bsize <= offset) {
1687 noffs = offset - bsize;
1690 /* clip other buffers */
1692 left = MIN (bsize - offset, size);
1694 if (offset != 0 || left != bsize) {
1695 if (gst_memory_is_writable (mem)) {
1696 gst_memory_resize (mem, offset, left);
1698 GstMemory *newmem = NULL;
1700 if (!GST_MEMORY_IS_NO_SHARE (mem))
1701 newmem = gst_memory_share (mem, offset, left);
1704 newmem = gst_memory_copy (mem, offset, left);
1709 gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (newmem),
1710 GST_MINI_OBJECT_CAST (buffer));
1711 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1712 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1713 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1714 gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (mem),
1715 GST_MINI_OBJECT_CAST (buffer));
1716 gst_memory_unref (mem);
1718 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1731 * @buffer: a #GstBuffer.
1732 * @info: (out): info about the mapping
1733 * @flags: flags for the mapping
1735 * This function fills @info with the #GstMapInfo of all merged memory
1736 * blocks in @buffer.
1738 * @flags describe the desired access of the memory. When @flags is
1739 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1740 * gst_buffer_is_writable()).
1742 * When @buffer is writable but the memory isn't, a writable copy will
1743 * automatically be created and returned. The readonly copy of the
1744 * buffer memory will then also be replaced with this writable copy.
1746 * The memory in @info should be unmapped with gst_buffer_unmap() after
1749 * Returns: %TRUE if the map succeeded and @info contains valid data.
1752 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1754 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1758 * gst_buffer_map_range:
1759 * @buffer: a #GstBuffer.
1762 * @info: (out): info about the mapping
1763 * @flags: flags for the mapping
1765 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1766 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1767 * from @idx are merged and mapped.
1769 * @flags describe the desired access of the memory. When @flags is
1770 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1771 * gst_buffer_is_writable()).
1773 * When @buffer is writable but the memory isn't, a writable copy will
1774 * automatically be created and returned. The readonly copy of the buffer memory
1775 * will then also be replaced with this writable copy.
1777 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1779 * Returns: %TRUE if the map succeeded and @info contains valid
1783 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1784 GstMapInfo * info, GstMapFlags flags)
1786 GstMemory *mem, *nmem;
1787 gboolean write, writable;
1790 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1791 g_return_val_if_fail (info != NULL, FALSE);
1792 len = GST_BUFFER_MEM_LEN (buffer);
1793 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1794 (length == -1 && idx < len) || (length > 0
1795 && length + idx <= len), FALSE);
1797 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1798 buffer, idx, length, flags);
1800 write = (flags & GST_MAP_WRITE) != 0;
1801 writable = gst_buffer_is_writable (buffer);
1803 /* check if we can write when asked for write access */
1804 if (G_UNLIKELY (write && !writable))
1810 mem = _get_merged_memory (buffer, idx, length);
1811 if (G_UNLIKELY (mem == NULL))
1814 /* now try to map */
1815 nmem = gst_memory_make_mapped (mem, info, flags);
1816 if (G_UNLIKELY (nmem == NULL))
1819 /* if we merged or when the map returned a different memory, we try to replace
1820 * the memory in the buffer */
1821 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1822 /* if the buffer is writable, replace the memory */
1824 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1827 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1828 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1837 GST_WARNING ("write map requested on non-writable buffer");
1838 g_critical ("write map requested on non-writable buffer");
1839 memset (info, 0, sizeof (GstMapInfo));
1844 /* empty buffer, we need to return NULL */
1845 GST_DEBUG ("can't get buffer memory");
1846 memset (info, 0, sizeof (GstMapInfo));
1851 GST_DEBUG ("cannot map memory");
1852 memset (info, 0, sizeof (GstMapInfo));
1859 * @buffer: a #GstBuffer.
1860 * @info: a #GstMapInfo
1862 * Release the memory previously mapped with gst_buffer_map().
1865 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1867 g_return_if_fail (GST_IS_BUFFER (buffer));
1868 g_return_if_fail (info != NULL);
1870 /* we need to check for NULL, it is possible that we tried to map a buffer
1871 * without memory and we should be able to unmap that fine */
1872 if (G_LIKELY (info->memory)) {
1873 gst_memory_unmap (info->memory, info);
1874 gst_memory_unref (info->memory);
1880 * @buffer: a #GstBuffer.
1881 * @offset: the offset to fill
1882 * @src: (array length=size) (element-type guint8): the source address
1883 * @size: the size to fill
1885 * Copy @size bytes from @src to @buffer at @offset.
1887 * Returns: The amount of bytes copied. This value can be lower than @size
1888 * when @buffer did not contain enough data.
1891 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1895 const guint8 *ptr = src;
1897 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1898 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1899 g_return_val_if_fail (src != NULL || size == 0, 0);
1901 GST_CAT_LOG (GST_CAT_BUFFER,
1902 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1905 len = GST_BUFFER_MEM_LEN (buffer);
1908 for (i = 0; i < len && left > 0; i++) {
1913 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1914 if (info.size > offset) {
1915 /* we have enough */
1916 tocopy = MIN (info.size - offset, left);
1917 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1922 /* offset past buffer, skip */
1923 offset -= info.size;
1925 gst_memory_unmap (mem, &info);
1931 * gst_buffer_extract:
1932 * @buffer: a #GstBuffer.
1933 * @offset: the offset to extract
1934 * @dest: (out caller-allocates) (array length=size) (element-type guint8):
1935 * the destination address
1936 * @size: the size to extract
1938 * Copy @size bytes starting from @offset in @buffer to @dest.
1940 * Returns: The amount of bytes extracted. This value can be lower than @size
1941 * when @buffer did not contain enough data.
1944 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1949 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1950 g_return_val_if_fail (dest != NULL, 0);
1952 GST_CAT_LOG (GST_CAT_BUFFER,
1953 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1956 len = GST_BUFFER_MEM_LEN (buffer);
1959 for (i = 0; i < len && left > 0; i++) {
1964 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1965 if (info.size > offset) {
1966 /* we have enough */
1967 tocopy = MIN (info.size - offset, left);
1968 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1973 /* offset past buffer, skip */
1974 offset -= info.size;
1976 gst_memory_unmap (mem, &info);
1982 * gst_buffer_memcmp:
1983 * @buffer: a #GstBuffer.
1984 * @offset: the offset in @buffer
1985 * @mem: (array length=size) (element-type guint8): the memory to compare
1986 * @size: the size to compare
1988 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1990 * Returns: 0 if the memory is equal.
1993 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1997 const guint8 *ptr = mem;
2000 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
2001 g_return_val_if_fail (mem != NULL, 0);
2003 GST_CAT_LOG (GST_CAT_BUFFER,
2004 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
2007 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
2010 len = GST_BUFFER_MEM_LEN (buffer);
2012 for (i = 0; i < len && size > 0 && res == 0; i++) {
2017 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
2018 if (info.size > offset) {
2019 /* we have enough */
2020 tocmp = MIN (info.size - offset, size);
2021 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
2026 /* offset past buffer, skip */
2027 offset -= info.size;
2029 gst_memory_unmap (mem, &info);
2035 * gst_buffer_memset:
2036 * @buffer: a #GstBuffer.
2037 * @offset: the offset in @buffer
2038 * @val: the value to set
2039 * @size: the size to set
2041 * Fill @buf with @size bytes with @val starting from @offset.
2043 * Returns: The amount of bytes filled. This value can be lower than @size
2044 * when @buffer did not contain enough data.
2047 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
2051 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
2052 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
2054 GST_CAT_LOG (GST_CAT_BUFFER,
2055 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
2056 buffer, offset, val, size);
2058 len = GST_BUFFER_MEM_LEN (buffer);
2061 for (i = 0; i < len && left > 0; i++) {
2066 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
2067 if (info.size > offset) {
2068 /* we have enough */
2069 toset = MIN (info.size - offset, left);
2070 memset ((guint8 *) info.data + offset, val, toset);
2074 /* offset past buffer, skip */
2075 offset -= info.size;
2077 gst_memory_unmap (mem, &info);
2083 * gst_buffer_copy_region:
2084 * @parent: a #GstBuffer.
2085 * @flags: the #GstBufferCopyFlags
2086 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
2088 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
2091 * Creates a sub-buffer from @parent at @offset and @size.
2092 * This sub-buffer uses the actual memory space of the parent buffer.
2093 * This function will copy the offset and timestamp fields when the
2094 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
2095 * #GST_BUFFER_OFFSET_NONE.
2096 * If @offset equals 0 and @size equals the total size of @buffer, the
2097 * duration and offset end fields are also copied. If not they will be set
2098 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
2102 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
2106 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
2107 gsize offset, gsize size)
2111 g_return_val_if_fail (buffer != NULL, NULL);
2113 /* create the new buffer */
2114 copy = gst_buffer_new ();
2116 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
2117 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
2119 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
2120 gst_buffer_replace (©, NULL);
2126 * gst_buffer_append:
2127 * @buf1: (transfer full): the first source #GstBuffer to append.
2128 * @buf2: (transfer full): the second source #GstBuffer to append.
2130 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
2131 * concatenation of the memory of @buf1 and @buf2.
2133 * Returns: (transfer full): the new #GstBuffer that contains the memory
2134 * of the two source buffers.
2137 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
2139 return gst_buffer_append_region (buf1, buf2, 0, -1);
2143 * gst_buffer_append_region:
2144 * @buf1: (transfer full): the first source #GstBuffer to append.
2145 * @buf2: (transfer full): the second source #GstBuffer to append.
2146 * @offset: the offset in @buf2
2147 * @size: the size or -1 of @buf2
2149 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
2150 * contain a concatenation of the memory of @buf1 and the requested region of
2153 * Returns: (transfer full): the new #GstBuffer that contains the memory
2154 * of the two source buffers.
2157 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
2162 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
2163 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
2165 buf1 = gst_buffer_make_writable (buf1);
2166 buf2 = gst_buffer_make_writable (buf2);
2168 gst_buffer_resize (buf2, offset, size);
2170 len = GST_BUFFER_MEM_LEN (buf2);
2171 for (i = 0; i < len; i++) {
2174 mem = GST_BUFFER_MEM_PTR (buf2, i);
2175 gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (mem),
2176 GST_MINI_OBJECT_CAST (buf2));
2177 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
2178 _memory_add (buf1, -1, mem);
2181 GST_BUFFER_MEM_LEN (buf2) = 0;
2182 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
2183 gst_buffer_unref (buf2);
2189 * gst_buffer_get_meta:
2190 * @buffer: a #GstBuffer
2191 * @api: the #GType of an API
2193 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
2194 * returned. If multiple metadata with the given @api are attached to this
2195 * buffer only the first one is returned. To handle multiple metadata with a
2196 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
2197 * and check the meta->info.api member for the API type.
2199 * Returns: (transfer none) (nullable): the metadata for @api on
2203 gst_buffer_get_meta (GstBuffer * buffer, GType api)
2206 GstMeta *result = NULL;
2208 g_return_val_if_fail (buffer != NULL, NULL);
2209 g_return_val_if_fail (api != 0, NULL);
2211 /* find GstMeta of the requested API */
2212 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
2213 GstMeta *meta = &item->meta;
2214 if (meta->info->api == api) {
2223 * gst_buffer_get_n_meta:
2224 * @buffer: a #GstBuffer
2225 * @api_type: the #GType of an API
2227 * Returns: number of metas of type @api_type on @buffer.
2232 gst_buffer_get_n_meta (GstBuffer * buffer, GType api_type)
2234 gpointer state = NULL;
2238 while ((meta = gst_buffer_iterate_meta_filtered (buffer, &state, api_type)))
2245 * gst_buffer_add_meta:
2246 * @buffer: a #GstBuffer
2247 * @info: a #GstMetaInfo
2248 * @params: params for @info
2250 * Add metadata for @info to @buffer using the parameters in @params.
2252 * Returns: (transfer none) (nullable): the metadata for the api in @info on @buffer.
2255 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2259 GstMeta *result = NULL;
2262 g_return_val_if_fail (buffer != NULL, NULL);
2263 g_return_val_if_fail (info != NULL, NULL);
2264 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2266 /* create a new slice */
2267 size = ITEM_SIZE (info);
2268 /* We warn in gst_meta_register() about metas without
2269 * init function but let's play safe here and prevent
2270 * uninitialized memory
2272 if (!info->init_func)
2273 item = g_slice_alloc0 (size);
2275 item = g_slice_alloc (size);
2276 result = &item->meta;
2277 result->info = info;
2278 result->flags = GST_META_FLAG_NONE;
2279 GST_CAT_DEBUG (GST_CAT_BUFFER,
2280 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2281 g_type_name (info->type), info->size);
2283 /* call the init_func when needed */
2284 if (info->init_func)
2285 if (!info->init_func (result, params, buffer))
2288 item->seq_num = gst_atomic_int64_inc (&meta_seq);
2291 if (!GST_BUFFER_META (buffer)) {
2292 GST_BUFFER_META (buffer) = item;
2293 GST_BUFFER_TAIL_META (buffer) = item;
2295 GST_BUFFER_TAIL_META (buffer)->next = item;
2296 GST_BUFFER_TAIL_META (buffer) = item;
2303 g_slice_free1 (size, item);
2309 * gst_buffer_remove_meta:
2310 * @buffer: a #GstBuffer
2313 * Remove the metadata for @meta on @buffer.
2315 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2316 * metadata was on @buffer.
2319 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2321 GstMetaItem *walk, *prev;
2323 g_return_val_if_fail (buffer != NULL, FALSE);
2324 g_return_val_if_fail (meta != NULL, FALSE);
2325 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2326 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2329 /* find the metadata and delete */
2330 prev = GST_BUFFER_META (buffer);
2331 for (walk = prev; walk; walk = walk->next) {
2332 GstMeta *m = &walk->meta;
2334 const GstMetaInfo *info = meta->info;
2336 /* remove from list */
2337 if (GST_BUFFER_TAIL_META (buffer) == walk) {
2339 GST_BUFFER_TAIL_META (buffer) = prev;
2341 GST_BUFFER_TAIL_META (buffer) = NULL;
2344 if (GST_BUFFER_META (buffer) == walk)
2345 GST_BUFFER_META (buffer) = walk->next;
2347 prev->next = walk->next;
2349 /* call free_func if any */
2350 if (info->free_func)
2351 info->free_func (m, buffer);
2353 /* and free the slice */
2354 g_slice_free1 (ITEM_SIZE (info), walk);
2359 return walk != NULL;
2363 * gst_buffer_iterate_meta: (skip)
2364 * @buffer: a #GstBuffer
2365 * @state: (out caller-allocates): an opaque state pointer
2367 * Retrieve the next #GstMeta after @current. If @state points
2368 * to %NULL, the first metadata is returned.
2370 * @state will be updated with an opaque state pointer
2372 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2373 * when there are no more items.
2376 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2380 g_return_val_if_fail (buffer != NULL, NULL);
2381 g_return_val_if_fail (state != NULL, NULL);
2383 meta = (GstMetaItem **) state;
2385 /* state NULL, move to first item */
2386 *meta = GST_BUFFER_META (buffer);
2388 /* state !NULL, move to next item in list */
2389 *meta = (*meta)->next;
2392 return &(*meta)->meta;
2398 * gst_buffer_iterate_meta_filtered: (skip)
2399 * @buffer: a #GstBuffer
2400 * @state: (out caller-allocates): an opaque state pointer
2401 * @meta_api_type: only return #GstMeta of this type
2403 * Retrieve the next #GstMeta of type @meta_api_type after the current one
2404 * according to @state. If @state points to %NULL, the first metadata of
2405 * type @meta_api_type is returned.
2407 * @state will be updated with an opaque state pointer
2409 * Returns: (transfer none) (nullable): The next #GstMeta of type
2410 * @meta_api_type or %NULL when there are no more items.
2415 gst_buffer_iterate_meta_filtered (GstBuffer * buffer, gpointer * state,
2416 GType meta_api_type)
2420 g_return_val_if_fail (buffer != NULL, NULL);
2421 g_return_val_if_fail (state != NULL, NULL);
2423 meta = (GstMetaItem **) state;
2425 /* state NULL, move to first item */
2426 *meta = GST_BUFFER_META (buffer);
2428 /* state !NULL, move to next item in list */
2429 *meta = (*meta)->next;
2431 while (*meta != NULL && (*meta)->meta.info->api != meta_api_type)
2432 *meta = (*meta)->next;
2435 return &(*meta)->meta;
2441 * gst_buffer_foreach_meta:
2442 * @buffer: a #GstBuffer
2443 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2444 * @user_data: (closure): user data passed to @func
2446 * Call @func with @user_data for each meta in @buffer.
2448 * @func can modify the passed meta pointer or its contents. The return value
2449 * of @func define if this function returns or if the remaining metadata items
2450 * in the buffer should be skipped.
2452 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2455 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2458 GstMetaItem *walk, *prev, *next;
2459 gboolean res = TRUE;
2461 g_return_val_if_fail (buffer != NULL, FALSE);
2462 g_return_val_if_fail (func != NULL, FALSE);
2464 /* find the metadata and delete */
2465 prev = GST_BUFFER_META (buffer);
2466 for (walk = prev; walk; walk = next) {
2469 m = new = &walk->meta;
2472 res = func (buffer, &new, user_data);
2475 const GstMetaInfo *info = m->info;
2477 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2478 g_type_name (info->type));
2480 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2481 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2484 if (GST_BUFFER_TAIL_META (buffer) == walk) {
2486 GST_BUFFER_TAIL_META (buffer) = prev;
2488 GST_BUFFER_TAIL_META (buffer) = NULL;
2491 /* remove from list */
2492 if (GST_BUFFER_META (buffer) == walk)
2493 prev = GST_BUFFER_META (buffer) = next;
2497 /* call free_func if any */
2498 if (info->free_func)
2499 info->free_func (m, buffer);
2501 /* and free the slice */
2502 g_slice_free1 (ITEM_SIZE (info), walk);
2513 * gst_buffer_extract_dup:
2514 * @buffer: a #GstBuffer
2515 * @offset: the offset to extract
2516 * @size: the size to extract
2517 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2518 * the destination array will be written. Might be %NULL if the size is 0.
2519 * @dest_size: (out): A location where the size of @dest can be written
2521 * Extracts a copy of at most @size bytes the data at @offset into
2522 * newly-allocated memory. @dest must be freed using g_free() when done.
2528 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2529 gpointer * dest, gsize * dest_size)
2531 gsize real_size, alloc_size;
2533 real_size = gst_buffer_get_size (buffer);
2535 alloc_size = MIN (real_size - offset, size);
2536 if (alloc_size == 0) {
2540 *dest = g_malloc (alloc_size);
2541 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);
2545 GST_DEBUG_CATEGORY_STATIC (gst_parent_buffer_meta_debug);
2548 * gst_buffer_add_parent_buffer_meta:
2549 * @buffer: (transfer none): a #GstBuffer
2550 * @ref: (transfer none): a #GstBuffer to ref
2552 * Add a #GstParentBufferMeta to @buffer that holds a reference on
2553 * @ref until the buffer is freed.
2555 * Returns: (transfer none) (nullable): The #GstParentBufferMeta that was added to the buffer
2559 GstParentBufferMeta *
2560 gst_buffer_add_parent_buffer_meta (GstBuffer * buffer, GstBuffer * ref)
2562 GstParentBufferMeta *meta;
2564 g_return_val_if_fail (GST_IS_BUFFER (ref), NULL);
2567 (GstParentBufferMeta *) gst_buffer_add_meta (buffer,
2568 GST_PARENT_BUFFER_META_INFO, NULL);
2573 meta->buffer = gst_buffer_ref (ref);
2579 _gst_parent_buffer_meta_transform (GstBuffer * dest, GstMeta * meta,
2580 GstBuffer * buffer, GQuark type, gpointer data)
2582 GstParentBufferMeta *dmeta, *smeta;
2584 smeta = (GstParentBufferMeta *) meta;
2586 if (GST_META_TRANSFORM_IS_COPY (type)) {
2587 /* copy over the reference to the parent buffer.
2588 * Usually, this meta means we need to keep the parent buffer
2589 * alive because one of the child memories is in use, which
2590 * might not be the case if memory is deep copied or sub-regioned,
2591 * but we can't tell, so keep the meta */
2592 dmeta = gst_buffer_add_parent_buffer_meta (dest, smeta->buffer);
2596 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2597 "copy buffer reference metadata");
2599 /* return FALSE, if transform type is not supported */
2606 _gst_parent_buffer_meta_free (GstParentBufferMeta * parent_meta,
2609 GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
2610 "Dropping reference on buffer %p", parent_meta->buffer);
2611 gst_buffer_unref (parent_meta->buffer);
2615 _gst_parent_buffer_meta_init (GstParentBufferMeta * parent_meta,
2616 gpointer params, GstBuffer * buffer)
2618 static volatile gsize _init;
2620 if (g_once_init_enter (&_init)) {
2621 GST_DEBUG_CATEGORY_INIT (gst_parent_buffer_meta_debug, "parentbuffermeta",
2622 0, "parentbuffermeta");
2623 g_once_init_leave (&_init, 1);
2626 parent_meta->buffer = NULL;
2632 gst_parent_buffer_meta_api_get_type (void)
2634 static volatile GType type = 0;
2635 static const gchar *tags[] = { NULL };
2637 if (g_once_init_enter (&type)) {
2638 GType _type = gst_meta_api_type_register ("GstParentBufferMetaAPI", tags);
2639 g_once_init_leave (&type, _type);
2646 * gst_parent_buffer_meta_get_info:
2648 * Get the global #GstMetaInfo describing the #GstParentBufferMeta meta.
2650 * Returns: (transfer none): The #GstMetaInfo
2655 gst_parent_buffer_meta_get_info (void)
2657 static const GstMetaInfo *meta_info = NULL;
2659 if (g_once_init_enter ((GstMetaInfo **) & meta_info)) {
2660 const GstMetaInfo *meta =
2661 gst_meta_register (gst_parent_buffer_meta_api_get_type (),
2662 "GstParentBufferMeta",
2663 sizeof (GstParentBufferMeta),
2664 (GstMetaInitFunction) _gst_parent_buffer_meta_init,
2665 (GstMetaFreeFunction) _gst_parent_buffer_meta_free,
2666 _gst_parent_buffer_meta_transform);
2667 g_once_init_leave ((GstMetaInfo **) & meta_info, (GstMetaInfo *) meta);
2673 GST_DEBUG_CATEGORY_STATIC (gst_reference_timestamp_meta_debug);
2676 * gst_buffer_add_reference_timestamp_meta:
2677 * @buffer: (transfer none): a #GstBuffer
2678 * @reference: (transfer none): identifier for the timestamp reference.
2679 * @timestamp: timestamp
2680 * @duration: duration, or %GST_CLOCK_TIME_NONE
2682 * Add a #GstReferenceTimestampMeta to @buffer that holds a @timestamp and
2683 * optionally @duration based on a specific timestamp @reference. See the
2684 * documentation of #GstReferenceTimestampMeta for details.
2686 * Returns: (transfer none) (nullable): The #GstReferenceTimestampMeta that was added to the buffer
2690 GstReferenceTimestampMeta *
2691 gst_buffer_add_reference_timestamp_meta (GstBuffer * buffer,
2692 GstCaps * reference, GstClockTime timestamp, GstClockTime duration)
2694 GstReferenceTimestampMeta *meta;
2696 g_return_val_if_fail (GST_IS_CAPS (reference), NULL);
2697 g_return_val_if_fail (timestamp != GST_CLOCK_TIME_NONE, NULL);
2700 (GstReferenceTimestampMeta *) gst_buffer_add_meta (buffer,
2701 GST_REFERENCE_TIMESTAMP_META_INFO, NULL);
2706 meta->reference = gst_caps_ref (reference);
2707 meta->timestamp = timestamp;
2708 meta->duration = duration;
2714 * gst_buffer_get_reference_timestamp_meta:
2715 * @buffer: a #GstBuffer
2716 * @reference: (allow-none): a reference #GstCaps
2718 * Find the first #GstReferenceTimestampMeta on @buffer that conforms to
2719 * @reference. Conformance is tested by checking if the meta's reference is a
2720 * subset of @reference.
2722 * Buffers can contain multiple #GstReferenceTimestampMeta metadata items.
2724 * Returns: (transfer none) (nullable): the #GstReferenceTimestampMeta or %NULL when there
2725 * is no such metadata on @buffer.
2729 GstReferenceTimestampMeta *
2730 gst_buffer_get_reference_timestamp_meta (GstBuffer * buffer,
2731 GstCaps * reference)
2733 gpointer state = NULL;
2735 const GstMetaInfo *info = GST_REFERENCE_TIMESTAMP_META_INFO;
2737 while ((meta = gst_buffer_iterate_meta (buffer, &state))) {
2738 if (meta->info->api == info->api) {
2739 GstReferenceTimestampMeta *rmeta = (GstReferenceTimestampMeta *) meta;
2743 if (gst_caps_is_subset (rmeta->reference, reference))
2751 _gst_reference_timestamp_meta_transform (GstBuffer * dest, GstMeta * meta,
2752 GstBuffer * buffer, GQuark type, gpointer data)
2754 GstReferenceTimestampMeta *dmeta, *smeta;
2756 /* we copy over the reference timestamp meta, independent of transformation
2757 * that happens. If it applied to the original buffer, it still applies to
2758 * the new buffer as it refers to the time when the media was captured */
2759 smeta = (GstReferenceTimestampMeta *) meta;
2761 gst_buffer_add_reference_timestamp_meta (dest, smeta->reference,
2762 smeta->timestamp, smeta->duration);
2766 GST_CAT_DEBUG (gst_reference_timestamp_meta_debug,
2767 "copy reference timestamp metadata from buffer %p to %p", buffer, dest);
2773 _gst_reference_timestamp_meta_free (GstReferenceTimestampMeta * meta,
2776 if (meta->reference)
2777 gst_caps_unref (meta->reference);
2781 _gst_reference_timestamp_meta_init (GstReferenceTimestampMeta * meta,
2782 gpointer params, GstBuffer * buffer)
2784 static volatile gsize _init;
2786 if (g_once_init_enter (&_init)) {
2787 GST_DEBUG_CATEGORY_INIT (gst_reference_timestamp_meta_debug,
2788 "referencetimestampmeta", 0, "referencetimestampmeta");
2789 g_once_init_leave (&_init, 1);
2792 meta->reference = NULL;
2793 meta->timestamp = GST_CLOCK_TIME_NONE;
2794 meta->duration = GST_CLOCK_TIME_NONE;
2800 gst_reference_timestamp_meta_api_get_type (void)
2802 static volatile GType type = 0;
2803 static const gchar *tags[] = { NULL };
2805 if (g_once_init_enter (&type)) {
2807 gst_meta_api_type_register ("GstReferenceTimestampMetaAPI", tags);
2808 g_once_init_leave (&type, _type);
2815 * gst_reference_timestamp_meta_get_info:
2817 * Get the global #GstMetaInfo describing the #GstReferenceTimestampMeta meta.
2819 * Returns: (transfer none): The #GstMetaInfo
2824 gst_reference_timestamp_meta_get_info (void)
2826 static const GstMetaInfo *meta_info = NULL;
2828 if (g_once_init_enter ((GstMetaInfo **) & meta_info)) {
2829 const GstMetaInfo *meta =
2830 gst_meta_register (gst_reference_timestamp_meta_api_get_type (),
2831 "GstReferenceTimestampMeta",
2832 sizeof (GstReferenceTimestampMeta),
2833 (GstMetaInitFunction) _gst_reference_timestamp_meta_init,
2834 (GstMetaFreeFunction) _gst_reference_timestamp_meta_free,
2835 _gst_reference_timestamp_meta_transform);
2836 g_once_init_leave ((GstMetaInfo **) & meta_info, (GstMetaInfo *) meta);