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.
37 * <title>Creating a buffer for a video frame</title>
41 * gint size, width, height, bpp;
43 * size = width * height * bpp;
44 * buffer = gst_buffer_new ();
45 * memory = gst_allocator_alloc (NULL, size, NULL);
46 * gst_buffer_insert_memory (buffer, -1, memory);
51 * Alternatively, use gst_buffer_new_allocate()
52 * to create a buffer with preallocated data of a given size.
54 * Buffers can contain a list of #GstMemory objects. You can retrieve how many
55 * memory objects with gst_buffer_n_memory() and you can get a pointer
56 * to memory with gst_buffer_peek_memory()
58 * A buffer will usually have timestamps, and a duration, but neither of these
59 * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
60 * meaningful value can be given for these, they should be set. The timestamps
61 * and duration are measured in nanoseconds (they are #GstClockTime values).
63 * The buffer DTS refers to the timestamp when the buffer should be decoded and
64 * is usually monotonically increasing. The buffer PTS refers to the timestamp when
65 * the buffer content should be presented to the user and is not always
66 * monotonically increasing.
68 * A buffer can also have one or both of a start and an end offset. These are
69 * media-type specific. For video buffers, the start offset will generally be
70 * the frame number. For audio buffers, it will be the number of samples
71 * produced so far. For compressed data, it could be the byte offset in a
72 * source or destination file. Likewise, the end offset will be the offset of
73 * the end of the buffer. These can only be meaningfully interpreted if you
74 * know the media type of the buffer (the preceding CAPS event). Either or both
75 * can be set to #GST_BUFFER_OFFSET_NONE.
77 * gst_buffer_ref() is used to increase the refcount of a buffer. This must be
78 * done when you want to keep a handle to the buffer after pushing it to the
79 * next element. The buffer refcount determines the writability of the buffer, a
80 * buffer is only writable when the refcount is exactly 1, i.e. when the caller
81 * has the only reference to the buffer.
83 * To efficiently create a smaller buffer out of an existing one, you can
84 * use gst_buffer_copy_region(). This method tries to share the memory objects
85 * between the two buffers.
87 * If a plug-in wants to modify the buffer data or metadata in-place, it should
88 * first obtain a buffer that is safe to modify by using
89 * gst_buffer_make_writable(). This function is optimized so that a copy will
90 * only be made when it is necessary.
92 * Several flags of the buffer can be set and unset with the
93 * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
94 * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlags flag is set.
96 * Buffers can be efficiently merged into a larger buffer with
97 * gst_buffer_append(). Copying of memory will only be done when absolutely
100 * Arbitrary extra metadata can be set on a buffer with gst_buffer_add_meta().
101 * Metadata can be retrieved with gst_buffer_get_meta(). See also #GstMeta
103 * An element should either unref the buffer or push it out on a src pad
104 * using gst_pad_push() (see #GstPad).
106 * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
107 * the refcount drops to 0, any memory and metadata pointed to by the buffer is
108 * unreffed as well. Buffers allocated from a #GstBufferPool will be returned to
109 * the pool when the refcount drops to 0.
111 * Last reviewed on 2012-03-28 (0.11.3)
113 #include "gst_private.h"
122 #include "gstbuffer.h"
123 #include "gstbufferpool.h"
125 #include "gstutils.h"
126 #include "gstversion.h"
128 GType _gst_buffer_type = 0;
130 typedef struct _GstMetaItem GstMetaItem;
137 #define ITEM_SIZE(info) ((info)->size + sizeof (GstMetaItem))
139 #define GST_BUFFER_MEM_MAX 16
141 #define GST_BUFFER_SLICE_SIZE(b) (((GstBufferImpl *)(b))->slice_size)
142 #define GST_BUFFER_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
143 #define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
144 #define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
145 #define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
146 #define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
154 /* the memory blocks */
156 GstMemory *mem[GST_BUFFER_MEM_MAX];
158 /* memory of the buffer when allocated from 1 chunk */
161 /* FIXME, make metadata allocation more efficient by using part of the
168 _is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
170 GstMemory *mcur, *mprv;
171 gboolean have_offset = FALSE;
176 for (i = 0; i < len; i++) {
184 /* check if memory is contiguous */
185 if (!gst_memory_is_span (mprv, mcur, &poffs))
192 *parent = mprv->parent;
202 _get_merged_memory (GstBuffer * buffer, guint idx, guint length)
204 GstMemory **mem, *result = NULL;
206 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %u", buffer, idx,
209 mem = GST_BUFFER_MEM_ARRAY (buffer);
211 if (G_UNLIKELY (length == 0)) {
213 } else if (G_LIKELY (length == 1)) {
214 result = gst_memory_ref (mem[idx]);
216 GstMemory *parent = NULL;
217 gsize size, poffset = 0;
219 size = gst_buffer_get_sizes_range (buffer, idx, length, NULL, NULL);
221 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
222 if (!GST_MEMORY_IS_NO_SHARE (parent))
223 result = gst_memory_share (parent, poffset, size);
225 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
226 result = gst_memory_copy (parent, poffset, size);
229 gsize i, tocopy, left;
230 GstMapInfo sinfo, dinfo;
233 result = gst_allocator_alloc (NULL, size, NULL);
234 gst_memory_map (result, &dinfo, GST_MAP_WRITE);
239 for (i = idx; i < (idx + length) && left > 0; i++) {
240 gst_memory_map (mem[i], &sinfo, GST_MAP_READ);
241 tocopy = MIN (sinfo.size, left);
242 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
243 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
244 tocopy, result, mem[i]);
245 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
248 gst_memory_unmap (mem[i], &sinfo);
250 gst_memory_unmap (result, &dinfo);
257 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
264 GST_CAT_LOG (GST_CAT_BUFFER,
265 "buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
268 /* unref old memory */
269 for (i = idx; i < end; i++) {
270 GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
272 gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
273 gst_memory_unref (old);
277 /* replace with single memory */
278 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
279 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
285 memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
286 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
288 GST_BUFFER_MEM_LEN (buffer) = len - length;
289 GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
293 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem, gboolean lock)
295 guint i, len = GST_BUFFER_MEM_LEN (buffer);
297 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p, lock %d", buffer,
300 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
301 /* too many buffer, span them. */
302 /* FIXME, there is room for improvement here: We could only try to merge
303 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
304 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
305 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
307 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
308 /* we now have 1 single spanned buffer */
315 for (i = len; i > idx; i--) {
316 /* move buffers to insert, FIXME, we need to insert first and then merge */
317 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
319 /* and insert the new buffer */
321 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
322 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
323 GST_BUFFER_MEM_LEN (buffer) = len + 1;
325 GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
328 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
331 _priv_gst_buffer_initialize (void)
333 _gst_buffer_type = gst_buffer_get_type ();
337 * gst_buffer_get_max_memory:
339 * Get the maximum amount of memory blocks that a buffer can hold. This is a
340 * compile time constant that can be queried with the function.
342 * When more memory blocks are added, existing memory blocks will be merged
343 * together to make room for the new block.
345 * Returns: the maximum amount of memory blocks that a buffer can hold.
350 gst_buffer_get_max_memory (void)
352 return GST_BUFFER_MEM_MAX;
356 * gst_buffer_copy_into:
357 * @dest: a destination #GstBuffer
358 * @src: a source #GstBuffer
359 * @flags: flags indicating what metadata fields should be copied.
360 * @offset: offset to copy from
361 * @size: total size to copy. If -1, all data is copied.
363 * Copies the information from @src into @dest.
365 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
366 * the memory from @src will be appended to @dest.
368 * @flags indicate which fields will be copied.
370 * Returns: %TRUE if the copying succeeded, %FALSE otherwise.
373 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
374 GstBufferCopyFlags flags, gsize offset, gsize size)
378 gboolean region = FALSE;
380 g_return_val_if_fail (dest != NULL, FALSE);
381 g_return_val_if_fail (src != NULL, FALSE);
383 /* nothing to copy if the buffers are the same */
384 if (G_UNLIKELY (dest == src))
387 g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
389 bufsize = gst_buffer_get_size (src);
390 g_return_val_if_fail (bufsize >= offset, FALSE);
394 size = bufsize - offset;
397 g_return_val_if_fail (bufsize >= offset + size, FALSE);
399 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
400 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
403 if (flags & GST_BUFFER_COPY_FLAGS) {
405 GST_MINI_OBJECT_FLAGS (dest) = GST_MINI_OBJECT_FLAGS (src);
408 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
410 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
411 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
412 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
413 if (size == bufsize) {
414 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
415 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
418 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
419 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
420 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
421 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
422 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
426 if (flags & GST_BUFFER_COPY_MEMORY) {
427 gsize skip, left, len, dest_len, i, bsize;
430 deep = flags & GST_BUFFER_COPY_DEEP;
432 len = GST_BUFFER_MEM_LEN (src);
433 dest_len = GST_BUFFER_MEM_LEN (dest);
437 /* copy and make regions of the memory */
438 for (i = 0; i < len && left > 0; i++) {
439 GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
441 bsize = gst_memory_get_sizes (mem, NULL, NULL);
444 /* don't copy buffer */
447 GstMemory *newmem = NULL;
450 tocopy = MIN (bsize - skip, left);
452 if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
453 /* we need to clip something */
454 newmem = gst_memory_share (mem, skip, tocopy);
459 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
460 /* deep copy or we're not allowed to share this memory
461 * between buffers, always copy then */
462 newmem = gst_memory_copy (mem, skip, tocopy);
464 } else if (!newmem) {
465 newmem = gst_memory_ref (mem);
469 gst_buffer_remove_memory_range (dest, dest_len, -1);
473 _memory_add (dest, -1, newmem, TRUE);
477 if (flags & GST_BUFFER_COPY_MERGE) {
480 len = GST_BUFFER_MEM_LEN (dest);
481 mem = _get_merged_memory (dest, 0, len);
483 gst_buffer_remove_memory_range (dest, dest_len, -1);
486 _replace_memory (dest, len, 0, len, mem);
490 if (flags & GST_BUFFER_COPY_META) {
491 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
492 GstMeta *meta = &walk->meta;
493 const GstMetaInfo *info = meta->info;
495 if (info->transform_func) {
496 GstMetaTransformCopy copy_data;
498 copy_data.region = region;
499 copy_data.offset = offset;
500 copy_data.size = size;
502 info->transform_func (dest, meta, src,
503 _gst_meta_transform_copy, ©_data);
512 _gst_buffer_copy (GstBuffer * buffer)
516 g_return_val_if_fail (buffer != NULL, NULL);
518 /* create a fresh new buffer */
519 copy = gst_buffer_new ();
521 /* we simply copy everything from our parent */
522 if (!gst_buffer_copy_into (copy, buffer, GST_BUFFER_COPY_ALL, 0, -1))
523 gst_buffer_replace (©, NULL);
525 GST_BUFFER_FLAG_SET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
530 /* the default dispose function revives the buffer and returns it to the
531 * pool when there is a pool */
533 _gst_buffer_dispose (GstBuffer * buffer)
537 /* no pool, do free */
538 if ((pool = buffer->pool) == NULL)
541 /* keep the buffer alive */
542 gst_buffer_ref (buffer);
543 /* return the buffer to the pool */
544 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
545 gst_buffer_pool_release_buffer (pool, buffer);
551 _gst_buffer_free (GstBuffer * buffer)
553 GstMetaItem *walk, *next;
557 g_return_if_fail (buffer != NULL);
559 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
562 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
563 GstMeta *meta = &walk->meta;
564 const GstMetaInfo *info = meta->info;
566 /* call free_func if any */
568 info->free_func (meta, buffer);
571 /* and free the slice */
572 g_slice_free1 (ITEM_SIZE (info), walk);
575 /* get the size, when unreffing the memory, we could also unref the buffer
577 msize = GST_BUFFER_SLICE_SIZE (buffer);
579 /* free our memory */
580 len = GST_BUFFER_MEM_LEN (buffer);
581 for (i = 0; i < len; i++) {
582 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
583 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
586 /* we set msize to 0 when the buffer is part of the memory block */
589 memset (buffer, 0xff, msize);
591 g_slice_free1 (msize, buffer);
593 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
598 gst_buffer_init (GstBufferImpl * buffer, gsize size)
600 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
601 (GstMiniObjectCopyFunction) _gst_buffer_copy,
602 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
603 (GstMiniObjectFreeFunction) _gst_buffer_free);
605 GST_BUFFER_SLICE_SIZE (buffer) = size;
607 GST_BUFFER (buffer)->pool = NULL;
608 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
609 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
610 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
611 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
612 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
614 GST_BUFFER_MEM_LEN (buffer) = 0;
615 GST_BUFFER_META (buffer) = NULL;
621 * Creates a newly allocated buffer without any data.
625 * Returns: (transfer full): the new #GstBuffer.
628 gst_buffer_new (void)
630 GstBufferImpl *newbuf;
632 newbuf = g_slice_new (GstBufferImpl);
633 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
635 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
637 return GST_BUFFER_CAST (newbuf);
641 * gst_buffer_new_allocate:
642 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or NULL to use the
644 * @size: the size in bytes of the new buffer's data.
645 * @params: (transfer none) (allow-none): optional parameters
647 * Tries to create a newly allocated buffer with data of the given size and
648 * extra parameters from @allocator. If the requested amount of memory can't be
649 * allocated, NULL will be returned. The allocated buffer memory is not cleared.
651 * When @allocator is NULL, the default memory allocator will be used.
653 * Note that when @size == 0, the buffer will not have memory associated with it.
657 * Returns: (transfer full): a new #GstBuffer, or NULL if the memory couldn't
661 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
662 GstAllocationParams * params)
673 mem = gst_allocator_alloc (allocator, size, params);
674 if (G_UNLIKELY (mem == NULL))
680 newbuf = gst_buffer_new ();
683 _memory_add (newbuf, -1, mem, TRUE);
685 GST_CAT_LOG (GST_CAT_BUFFER,
686 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
691 asize = sizeof (GstBufferImpl) + size;
692 data = g_slice_alloc (asize);
693 if (G_UNLIKELY (data == NULL))
696 newbuf = GST_BUFFER_CAST (data);
698 gst_buffer_init ((GstBufferImpl *) data, asize);
700 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
702 _memory_add (newbuf, -1, mem, TRUE);
707 /* allocate memory and buffer, it might be interesting to do this but there
708 * are many complications. We need to keep the memory mapped to access the
709 * buffer fields and the memory for the buffer might be just very slow. We
710 * also need to do some more magic to get the alignment right. */
711 asize = sizeof (GstBufferImpl) + size;
712 mem = gst_allocator_alloc (allocator, asize, align);
713 if (G_UNLIKELY (mem == NULL))
716 /* map the data part and init the buffer in it, set the buffer size to 0 so
717 * that a finalize won't free the buffer */
718 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
719 gst_buffer_init ((GstBufferImpl *) data, 0);
720 gst_memory_unmap (mem);
722 /* strip off the buffer */
723 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
725 newbuf = GST_BUFFER_CAST (data);
726 GST_BUFFER_BUFMEM (newbuf) = mem;
729 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
731 GST_BUFFER_FLAG_SET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
738 GST_CAT_WARNING (GST_CAT_BUFFER,
739 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
745 * gst_buffer_new_wrapped_full:
746 * @flags: #GstMemoryFlags
747 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
748 * @maxsize: allocated size of @data
749 * @offset: offset in @data
750 * @size: size of valid data
751 * @user_data: (allow-none): user_data
752 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
754 * Allocate a new buffer that wraps the given memory. @data must point to
755 * @maxsize of memory, the wrapped buffer will have the region from @offset and
758 * When the buffer is destroyed, @notify will be called with @user_data.
760 * The prefix/padding must be filled with 0 if @flags contains
761 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
763 * Returns: (transfer full): a new #GstBuffer
766 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
767 gsize maxsize, gsize offset, gsize size, gpointer user_data,
768 GDestroyNotify notify)
773 newbuf = gst_buffer_new ();
775 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
777 _memory_add (newbuf, -1, mem, TRUE);
778 GST_BUFFER_FLAG_SET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
784 * gst_buffer_new_wrapped:
785 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
786 * @size: allocated size of @data
788 * Creates a new buffer that wraps the given @data. The memory will be freed
789 * with g_free and will be marked writable.
793 * Returns: (transfer full): a new #GstBuffer
796 gst_buffer_new_wrapped (gpointer data, gsize size)
798 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
802 * gst_buffer_n_memory:
803 * @buffer: a #GstBuffer.
805 * Get the amount of memory blocks that this buffer has. This amount is never
806 * larger than what gst_buffer_get_max_memory() returns.
808 * Returns: (transfer full): the amount of memory block in this buffer.
811 gst_buffer_n_memory (GstBuffer * buffer)
813 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
815 return GST_BUFFER_MEM_LEN (buffer);
819 * gst_buffer_prepend_memory:
820 * @buffer: a #GstBuffer.
821 * @mem: (transfer full): a #GstMemory.
823 * Prepend the memory block @mem to @buffer. This function takes
824 * ownership of @mem and thus doesn't increase its refcount.
826 * This function is identical to gst_buffer_insert_memory() with an index of 0.
827 * See gst_buffer_insert_memory() for more details.
830 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
832 gst_buffer_insert_memory (buffer, 0, mem);
836 * gst_buffer_append_memory:
837 * @buffer: a #GstBuffer.
838 * @mem: (transfer full): a #GstMemory.
840 * Append the memory block @mem to @buffer. This function takes
841 * ownership of @mem and thus doesn't increase its refcount.
843 * This function is identical to gst_buffer_insert_memory() with an index of -1.
844 * See gst_buffer_insert_memory() for more details.
847 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
849 gst_buffer_insert_memory (buffer, -1, mem);
853 * gst_buffer_insert_memory:
854 * @buffer: a #GstBuffer.
855 * @idx: the index to add the memory at, or -1 to append it to the end
856 * @mem: (transfer full): a #GstMemory.
858 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
859 * of @mem and thus doesn't increase its refcount.
861 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
862 * added, existing memory blocks will automatically be merged to make room for
866 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
868 g_return_if_fail (GST_IS_BUFFER (buffer));
869 g_return_if_fail (gst_buffer_is_writable (buffer));
870 g_return_if_fail (mem != NULL);
871 g_return_if_fail (idx == -1 ||
872 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
874 _memory_add (buffer, idx, mem, TRUE);
878 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
881 GstMemory *mem, *mapped;
883 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
885 mapped = gst_memory_make_mapped (mem, info, flags);
888 /* memory changed, lock new memory */
889 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
890 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
891 /* unlock old memory */
892 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
893 GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
895 gst_memory_unref (mem);
901 * gst_buffer_peek_memory:
902 * @buffer: a #GstBuffer.
905 * Get the memory block at @idx in @buffer. The memory block stays valid until
906 * the memory block in @buffer is removed, replaced or merged, typically with
907 * any call that modifies the memory in @buffer.
909 * Returns: (transfer none): the #GstMemory at @idx.
912 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
916 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
917 len = GST_BUFFER_MEM_LEN (buffer);
918 g_return_val_if_fail (idx < len, NULL);
920 return GST_BUFFER_MEM_PTR (buffer, idx);
924 * gst_buffer_get_memory:
925 * @buffer: a #GstBuffer.
928 * Get the memory block at index @idx in @buffer.
930 * Returns: (transfer full): a #GstMemory that contains the data of the
931 * memory block at @idx. Use gst_memory_unref () after usage.
934 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
936 return gst_buffer_get_memory_range (buffer, idx, 1);
940 * gst_buffer_get_all_memory:
941 * @buffer: a #GstBuffer.
943 * Get all the memory block in @buffer. The memory blocks will be merged
944 * into one large #GstMemory.
946 * Returns: (transfer full): a #GstMemory that contains the merged memory.
947 * Use gst_memory_unref () after usage.
950 gst_buffer_get_all_memory (GstBuffer * buffer)
952 return gst_buffer_get_memory_range (buffer, 0, -1);
956 * gst_buffer_get_memory_range:
957 * @buffer: a #GstBuffer.
961 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
962 * be merged into one large #GstMemory.
964 * If @length is -1, all memory starting from @idx is merged.
966 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
967 * blocks starting at @idx. Use gst_memory_unref () after usage.
970 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
974 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
976 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
977 len = GST_BUFFER_MEM_LEN (buffer);
978 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
979 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
984 return _get_merged_memory (buffer, idx, length);
988 * gst_buffer_replace_memory:
989 * @buffer: a #GstBuffer.
991 * @mem: (transfer full): a #GstMemory
993 * Replaces the memory block at index @idx in @buffer with @mem.
996 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
998 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1002 * gst_buffer_replace_all_memory:
1003 * @buffer: a #GstBuffer.
1004 * @mem: (transfer full): a #GstMemory
1006 * Replaces all memory in @buffer with @mem.
1009 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1011 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1015 * gst_buffer_replace_memory_range:
1016 * @buffer: a #GstBuffer.
1018 * @length: a length should not be 0
1019 * @mem: (transfer full): a #GstMemory
1021 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1023 * If @length is -1, all memory starting from @idx will be removed and
1024 * replaced with @mem.
1026 * @buffer should be writable.
1029 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1034 g_return_if_fail (GST_IS_BUFFER (buffer));
1035 g_return_if_fail (gst_buffer_is_writable (buffer));
1037 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1039 len = GST_BUFFER_MEM_LEN (buffer);
1040 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1041 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1046 _replace_memory (buffer, len, idx, length, mem);
1050 * gst_buffer_remove_memory:
1051 * @buffer: a #GstBuffer.
1054 * Remove the memory block in @b at index @i.
1057 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1059 gst_buffer_remove_memory_range (buffer, idx, 1);
1063 * gst_buffer_remove_all_memory:
1064 * @buffer: a #GstBuffer.
1066 * Remove all the memory blocks in @buffer.
1069 gst_buffer_remove_all_memory (GstBuffer * buffer)
1071 gst_buffer_remove_memory_range (buffer, 0, -1);
1075 * gst_buffer_remove_memory_range:
1076 * @buffer: a #GstBuffer.
1080 * Remove @length memory blocks in @buffer starting from @idx.
1082 * @length can be -1, in which case all memory starting from @idx is removed.
1085 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1089 g_return_if_fail (GST_IS_BUFFER (buffer));
1090 g_return_if_fail (gst_buffer_is_writable (buffer));
1092 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1094 len = GST_BUFFER_MEM_LEN (buffer);
1095 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1096 (length == -1 && idx < len) || length + idx <= len);
1101 _replace_memory (buffer, len, idx, length, NULL);
1105 * gst_buffer_find_memory:
1106 * @buffer: a #GstBuffer.
1107 * @offset: an offset
1109 * @idx: (out): pointer to index
1110 * @length: (out): pointer to length
1111 * @skip: (out): pointer to skip
1113 * Find the memory blocks that span @size bytes starting from @offset
1116 * When this function returns %TRUE, @idx will contain the index of the first
1117 * memory bock where the byte for @offset can be found and @length contains the
1118 * number of memory blocks containing the @size remaining bytes. @skip contains
1119 * the number of bytes to skip in the memory bock at @idx to get to the byte
1122 * @size can be -1 to get all the memory blocks after @idx.
1124 * Returns: %TRUE when @size bytes starting from @offset could be found in
1125 * @buffer and @idx, @length and @skip will be filled.
1128 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1129 guint * idx, guint * length, gsize * skip)
1131 guint i, len, found;
1133 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1134 g_return_val_if_fail (idx != NULL, FALSE);
1135 g_return_val_if_fail (length != NULL, FALSE);
1136 g_return_val_if_fail (skip != NULL, FALSE);
1138 len = GST_BUFFER_MEM_LEN (buffer);
1141 for (i = 0; i < len; i++) {
1145 mem = GST_BUFFER_MEM_PTR (buffer, i);
1146 s = gst_memory_get_sizes (mem, NULL, NULL);
1149 /* block before offset, or empty block, skip */
1152 /* block after offset */
1154 /* first block, remember index and offset */
1158 /* return remaining blocks */
1165 /* count the amount of found bytes */
1167 if (found >= size) {
1168 /* we have enough bytes */
1169 *length = i - *idx + 1;
1178 * gst_buffer_get_sizes:
1179 * @buffer: a #GstBuffer.
1180 * @offset: (out): a pointer to the offset
1181 * @maxsize: (out): a pointer to the maxsize
1183 * Get the total size of the memory blocks in @b.
1185 * When not %NULL, @offset will contain the offset of the data in the
1186 * first memory block in @buffer and @maxsize will contain the sum of
1187 * the size and @offset and the amount of extra padding on the last
1188 * memory block. @offset and @maxsize can be used to resize the
1189 * buffer memory blocks with gst_buffer_resize().
1191 * Returns: total size of the memory blocks in @buffer.
1194 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1196 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1200 * gst_buffer_get_size:
1201 * @buffer: a #GstBuffer.
1203 * Get the total size of the memory blocks in @buffer.
1205 * Returns: total size of the memory blocks in @buffer.
1208 gst_buffer_get_size (GstBuffer * buffer)
1210 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1214 * gst_buffer_get_sizes_range:
1215 * @buffer: a #GstBuffer.
1218 * @offset: (out): a pointer to the offset
1219 * @maxsize: (out): a pointer to the maxsize
1221 * Get the total size of @length memory blocks stating from @idx in @buffer.
1223 * When not %NULL, @offset will contain the offset of the data in the
1224 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1225 * and @offset and the amount of extra padding on the memory block at @idx +
1227 * @offset and @maxsize can be used to resize the buffer memory blocks with
1228 * gst_buffer_resize_range().
1230 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1233 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1234 gsize * offset, gsize * maxsize)
1240 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1241 len = GST_BUFFER_MEM_LEN (buffer);
1242 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1243 (length == -1 && idx < len) || (length + idx <= len), 0);
1248 if (G_LIKELY (length == 1)) {
1250 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1251 size = gst_memory_get_sizes (mem, offset, maxsize);
1257 size = offs = extra = 0;
1258 for (i = idx; i < end; i++) {
1261 mem = GST_BUFFER_MEM_PTR (buffer, i);
1262 s = gst_memory_get_sizes (mem, &o, &ms);
1266 /* first size, take accumulated data before as the offset */
1270 /* save the amount of data after this block */
1271 extra = ms - (o + s);
1273 /* empty block, add as extra */
1280 *maxsize = offs + size + extra;
1286 * gst_buffer_resize:
1287 * @buffer: a #GstBuffer.
1288 * @offset: the offset adjustment
1289 * @size: the new size or -1 to just adjust the offset
1291 * Set the offset and total size of the memory blocks in @buffer.
1294 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1296 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1300 * gst_buffer_set_size:
1301 * @buffer: a #GstBuffer.
1302 * @size: the new size
1304 * Set the total size of the memory blocks in @buffer.
1307 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1309 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1313 * gst_buffer_resize_range:
1314 * @buffer: a #GstBuffer.
1317 * @offset: the offset adjustment
1318 * @size: the new size or -1 to just adjust the offset
1320 * Set the total size of the @length memory blocks starting at @idx in
1323 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1326 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1327 gssize offset, gssize size)
1330 gsize bsize, bufsize, bufoffs, bufmax;
1332 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1333 g_return_val_if_fail (size >= -1, FALSE);
1335 len = GST_BUFFER_MEM_LEN (buffer);
1336 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1337 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1342 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1344 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1345 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1346 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1348 /* we can't go back further than the current offset or past the end of the
1350 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1351 && bufoffs + offset <= bufmax), FALSE);
1353 g_return_val_if_fail (bufsize >= offset, FALSE);
1354 size = bufsize - offset;
1356 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1359 if (offset == 0 && size == bufsize)
1364 for (i = idx; i < end; i++) {
1368 mem = GST_BUFFER_MEM_PTR (buffer, i);
1369 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1372 /* last buffer always gets resized to the remaining size */
1375 /* shrink buffers before the offset */
1376 else if ((gssize) bsize <= offset) {
1378 noffs = offset - bsize;
1381 /* clip other buffers */
1383 left = MIN (bsize - offset, size);
1385 if (offset != 0 || left != bsize) {
1386 if (gst_memory_is_writable (mem)) {
1387 gst_memory_resize (mem, offset, left);
1389 GstMemory *newmem = NULL;
1391 if (!GST_MEMORY_IS_NO_SHARE (mem))
1392 newmem = gst_memory_share (mem, offset, left);
1395 newmem = gst_memory_copy (mem, offset, left);
1400 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1401 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1402 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1403 gst_memory_unref (mem);
1406 GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1418 * @buffer: a #GstBuffer.
1419 * @info: (out): info about the mapping
1420 * @flags: flags for the mapping
1422 * This function fills @info with the #GstMapInfo of all merged memory
1423 * blocks in @buffer.
1425 * @flags describe the desired access of the memory. When @flags is
1426 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1427 * gst_buffer_is_writable()).
1429 * When @buffer is writable but the memory isn't, a writable copy will
1430 * automatically be created and returned. The readonly copy of the
1431 * buffer memory will then also be replaced with this writable copy.
1433 * The memory in @info should be unmapped with gst_buffer_unmap() after
1436 * Returns: %TRUE if the map succeeded and @info contains valid data.
1439 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1441 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1445 * gst_buffer_map_range:
1446 * @buffer: a #GstBuffer.
1449 * @info: (out): info about the mapping
1450 * @flags: flags for the mapping
1452 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1453 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1454 * from @idx are merged and mapped.
1456 * @flags describe the desired access of the memory. When @flags is
1457 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1458 * gst_buffer_is_writable()).
1460 * When @buffer is writable but the memory isn't, a writable copy will
1461 * automatically be created and returned. The readonly copy of the buffer memory
1462 * will then also be replaced with this writable copy.
1464 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1466 * Returns: %TRUE if the map succeeded and @info contains valid
1470 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1471 GstMapInfo * info, GstMapFlags flags)
1473 GstMemory *mem, *nmem;
1474 gboolean write, writable;
1477 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1478 g_return_val_if_fail (info != NULL, FALSE);
1479 len = GST_BUFFER_MEM_LEN (buffer);
1480 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1481 (length == -1 && idx < len) || (length > 0
1482 && length + idx <= len), FALSE);
1484 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1485 buffer, idx, length, flags);
1487 write = (flags & GST_MAP_WRITE) != 0;
1488 writable = gst_buffer_is_writable (buffer);
1490 /* check if we can write when asked for write access */
1491 if (G_UNLIKELY (write && !writable))
1497 mem = _get_merged_memory (buffer, idx, length);
1498 if (G_UNLIKELY (mem == NULL))
1501 /* now try to map */
1502 nmem = gst_memory_make_mapped (mem, info, flags);
1503 if (G_UNLIKELY (nmem == NULL))
1506 /* if we merged or when the map returned a different memory, we try to replace
1507 * the memory in the buffer */
1508 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1509 /* if the buffer is writable, replace the memory */
1511 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1514 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1515 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1524 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1525 g_critical ("write map requested on non-writable buffer");
1530 /* empty buffer, we need to return NULL */
1531 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1532 info->memory = NULL;
1540 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1547 * @buffer: a #GstBuffer.
1548 * @info: a #GstMapInfo
1550 * Release the memory previously mapped with gst_buffer_map().
1553 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1555 g_return_if_fail (GST_IS_BUFFER (buffer));
1556 g_return_if_fail (info != NULL);
1558 /* we need to check for NULL, it is possible that we tried to map a buffer
1559 * without memory and we should be able to unmap that fine */
1560 if (G_LIKELY (info->memory)) {
1561 gst_memory_unmap (info->memory, info);
1562 gst_memory_unref (info->memory);
1568 * @buffer: a #GstBuffer.
1569 * @offset: the offset to fill
1570 * @src: (array length=size) (element-type guint8): the source address
1571 * @size: the size to fill
1573 * Copy @size bytes from @src to @buffer at @offset.
1575 * Returns: The amount of bytes copied. This value can be lower than @size
1576 * when @buffer did not contain enough data.
1579 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1583 const guint8 *ptr = src;
1585 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1586 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1587 g_return_val_if_fail (src != NULL || size == 0, 0);
1589 GST_CAT_LOG (GST_CAT_BUFFER,
1590 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1593 len = GST_BUFFER_MEM_LEN (buffer);
1596 for (i = 0; i < len && left > 0; i++) {
1601 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1602 if (info.size > offset) {
1603 /* we have enough */
1604 tocopy = MIN (info.size - offset, left);
1605 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1610 /* offset past buffer, skip */
1611 offset -= info.size;
1613 gst_memory_unmap (mem, &info);
1619 * gst_buffer_extract:
1620 * @buffer: a #GstBuffer.
1621 * @offset: the offset to extract
1622 * @dest: the destination address
1623 * @size: the size to extract
1625 * Copy @size bytes starting from @offset in @buffer to @dest.
1627 * Returns: The amount of bytes extracted. This value can be lower than @size
1628 * when @buffer did not contain enough data.
1631 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1636 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1637 g_return_val_if_fail (dest != NULL, 0);
1639 GST_CAT_LOG (GST_CAT_BUFFER,
1640 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1643 len = GST_BUFFER_MEM_LEN (buffer);
1646 for (i = 0; i < len && left > 0; i++) {
1651 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1652 if (info.size > offset) {
1653 /* we have enough */
1654 tocopy = MIN (info.size - offset, left);
1655 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1660 /* offset past buffer, skip */
1661 offset -= info.size;
1663 gst_memory_unmap (mem, &info);
1669 * gst_buffer_memcmp:
1670 * @buffer: a #GstBuffer.
1671 * @offset: the offset in @buffer
1672 * @mem: (array length=size) (element-type guint8): the memory to compare
1673 * @size: the size to compare
1675 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1677 * Returns: 0 if the memory is equal.
1680 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1684 const guint8 *ptr = mem;
1687 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1688 g_return_val_if_fail (mem != NULL, 0);
1690 GST_CAT_LOG (GST_CAT_BUFFER,
1691 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1694 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1697 len = GST_BUFFER_MEM_LEN (buffer);
1699 for (i = 0; i < len && size > 0 && res == 0; i++) {
1704 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1705 if (info.size > offset) {
1706 /* we have enough */
1707 tocmp = MIN (info.size - offset, size);
1708 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1713 /* offset past buffer, skip */
1714 offset -= info.size;
1716 gst_memory_unmap (mem, &info);
1722 * gst_buffer_memset:
1723 * @buffer: a #GstBuffer.
1724 * @offset: the offset in @buffer
1725 * @val: the value to set
1726 * @size: the size to set
1728 * Fill @buf with @size bytes with @val starting from @offset.
1730 * Returns: The amount of bytes filled. This value can be lower than @size
1731 * when @buffer did not contain enough data.
1734 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1738 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1739 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1741 GST_CAT_LOG (GST_CAT_BUFFER,
1742 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1743 buffer, offset, val, size);
1745 len = GST_BUFFER_MEM_LEN (buffer);
1748 for (i = 0; i < len && left > 0; i++) {
1753 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1754 if (info.size > offset) {
1755 /* we have enough */
1756 toset = MIN (info.size - offset, left);
1757 memset ((guint8 *) info.data + offset, val, toset);
1761 /* offset past buffer, skip */
1762 offset -= info.size;
1764 gst_memory_unmap (mem, &info);
1770 * gst_buffer_copy_region:
1771 * @parent: a #GstBuffer.
1772 * @flags: the #GstBufferCopyFlags
1773 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1775 * @size: the size of the new #GstBuffer sub-buffer, in bytes.
1777 * Creates a sub-buffer from @parent at @offset and @size.
1778 * This sub-buffer uses the actual memory space of the parent buffer.
1779 * This function will copy the offset and timestamp fields when the
1780 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1781 * #GST_BUFFER_OFFSET_NONE.
1782 * If @offset equals 0 and @size equals the total size of @buffer, the
1783 * duration and offset end fields are also copied. If not they will be set
1784 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1788 * Returns: (transfer full): the new #GstBuffer or NULL if the arguments were
1792 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1793 gsize offset, gsize size)
1797 g_return_val_if_fail (buffer != NULL, NULL);
1799 /* create the new buffer */
1800 copy = gst_buffer_new ();
1802 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1803 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1805 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1806 gst_buffer_replace (©, NULL);
1812 * gst_buffer_append:
1813 * @buf1: (transfer full): the first source #GstBuffer to append.
1814 * @buf2: (transfer full): the second source #GstBuffer to append.
1816 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1817 * concatenation of the memory of @buf1 and @buf2.
1819 * Returns: (transfer full): the new #GstBuffer that contains the memory
1820 * of the two source buffers.
1823 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1825 return gst_buffer_append_region (buf1, buf2, 0, -1);
1829 * gst_buffer_append_region:
1830 * @buf1: (transfer full): the first source #GstBuffer to append.
1831 * @buf2: (transfer full): the second source #GstBuffer to append.
1832 * @offset: the offset in @buf2
1833 * @size: the size or -1 of @buf2
1835 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1836 * contain a concatenation of the memory of @buf1 and the requested region of
1839 * Returns: (transfer full): the new #GstBuffer that contains the memory
1840 * of the two source buffers.
1843 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
1848 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1849 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1851 buf1 = gst_buffer_make_writable (buf1);
1852 buf2 = gst_buffer_make_writable (buf2);
1854 gst_buffer_resize (buf2, offset, size);
1856 len = GST_BUFFER_MEM_LEN (buf2);
1857 for (i = 0; i < len; i++) {
1860 mem = GST_BUFFER_MEM_PTR (buf2, i);
1861 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1862 _memory_add (buf1, -1, mem, FALSE);
1865 GST_BUFFER_MEM_LEN (buf2) = 0;
1866 GST_BUFFER_FLAG_UNSET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
1867 gst_buffer_unref (buf2);
1873 * gst_buffer_get_meta:
1874 * @buffer: a #GstBuffer
1875 * @api: the #GType of an API
1877 * Get the metadata for @api on buffer. When there is no such
1878 * metadata, NULL is returned.
1880 * Returns: (transfer none): the metadata for @api on @buffer.
1883 gst_buffer_get_meta (GstBuffer * buffer, GType api)
1886 GstMeta *result = NULL;
1888 g_return_val_if_fail (buffer != NULL, NULL);
1889 g_return_val_if_fail (api != 0, NULL);
1891 /* find GstMeta of the requested API */
1892 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
1893 GstMeta *meta = &item->meta;
1894 if (meta->info->api == api) {
1903 * gst_buffer_add_meta:
1904 * @buffer: a #GstBuffer
1905 * @info: a #GstMetaInfo
1906 * @params: params for @info
1908 * Add metadata for @info to @buffer using the parameters in @params.
1910 * Returns: (transfer none): the metadata for the api in @info on @buffer.
1913 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
1917 GstMeta *result = NULL;
1920 g_return_val_if_fail (buffer != NULL, NULL);
1921 g_return_val_if_fail (info != NULL, NULL);
1922 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
1924 /* create a new slice */
1925 size = ITEM_SIZE (info);
1926 item = g_slice_alloc (size);
1927 result = &item->meta;
1928 result->info = info;
1929 result->flags = GST_META_FLAG_NONE;
1931 GST_CAT_DEBUG (GST_CAT_BUFFER,
1932 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
1933 g_type_name (info->type), info->size);
1935 /* call the init_func when needed */
1936 if (info->init_func)
1937 if (!info->init_func (result, params, buffer))
1940 /* and add to the list of metadata */
1941 item->next = GST_BUFFER_META (buffer);
1942 GST_BUFFER_META (buffer) = item;
1948 g_slice_free1 (size, item);
1954 * gst_buffer_remove_meta:
1955 * @buffer: a #GstBuffer
1958 * Remove the metadata for @meta on @buffer.
1960 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
1961 * metadata was on @buffer.
1964 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
1966 GstMetaItem *walk, *prev;
1968 g_return_val_if_fail (buffer != NULL, FALSE);
1969 g_return_val_if_fail (meta != NULL, FALSE);
1970 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1971 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
1974 /* find the metadata and delete */
1975 prev = GST_BUFFER_META (buffer);
1976 for (walk = prev; walk; walk = walk->next) {
1977 GstMeta *m = &walk->meta;
1979 const GstMetaInfo *info = meta->info;
1981 /* remove from list */
1982 if (GST_BUFFER_META (buffer) == walk)
1983 GST_BUFFER_META (buffer) = walk->next;
1985 prev->next = walk->next;
1986 /* call free_func if any */
1987 if (info->free_func)
1988 info->free_func (m, buffer);
1990 /* and free the slice */
1991 g_slice_free1 (ITEM_SIZE (info), walk);
1996 return walk != NULL;
2000 * gst_buffer_iterate_meta:
2001 * @buffer: a #GstBuffer
2002 * @state: an opaque state pointer
2004 * Retrieve the next #GstMeta after @current. If @state points
2005 * to %NULL, the first metadata is returned.
2007 * @state will be updated with an opaque state pointer
2009 * Returns: (transfer none): The next #GstMeta or %NULL when there are
2013 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2017 g_return_val_if_fail (buffer != NULL, NULL);
2018 g_return_val_if_fail (state != NULL, NULL);
2020 meta = (GstMetaItem **) state;
2022 /* state NULL, move to first item */
2023 *meta = GST_BUFFER_META (buffer);
2025 /* state !NULL, move to next item in list */
2026 *meta = (*meta)->next;
2029 return &(*meta)->meta;
2035 * gst_buffer_foreach_meta:
2036 * @buffer: a #GstBuffer
2037 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2038 * @user_data: (closure): user data passed to @func
2040 * Call @func with @user_data for each meta in @buffer.
2042 * @func can modify the passed meta pointer or its contents. The return value
2043 * of @func define if this function returns or if the remaining metadata items
2044 * in the buffer should be skipped.
2046 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2049 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2052 GstMetaItem *walk, *prev, *next;
2053 gboolean res = TRUE;
2055 g_return_val_if_fail (buffer != NULL, FALSE);
2056 g_return_val_if_fail (func != NULL, FALSE);
2058 /* find the metadata and delete */
2059 prev = GST_BUFFER_META (buffer);
2060 for (walk = prev; walk; walk = next) {
2063 m = new = &walk->meta;
2066 res = func (buffer, &new, user_data);
2069 const GstMetaInfo *info = m->info;
2071 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2072 g_type_name (info->type));
2074 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2075 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2078 /* remove from list */
2079 if (GST_BUFFER_META (buffer) == walk)
2080 GST_BUFFER_META (buffer) = next;
2084 /* call free_func if any */
2085 if (info->free_func)
2086 info->free_func (m, buffer);
2088 /* and free the slice */
2089 g_slice_free1 (ITEM_SIZE (info), walk);
2098 * gst_buffer_extract_dup:
2099 * @buffer: a #GstBuffer
2100 * @offset: the offset to extract
2101 * @size: the size to extract
2102 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2103 * the destination array will be written.
2104 * @dest_size: (out): A location where the size of @dest can be written
2106 * Extracts a copy of at most @size bytes the data at @offset into a #GBytes.
2107 * @dest must be freed using g_free() when done.
2113 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2114 gpointer * dest, gsize * dest_size)
2118 real_size = gst_buffer_get_size (buffer);
2120 *dest = g_malloc (MIN (real_size - offset, size));
2122 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);