2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wtay@chello.be>
5 * gstbuffer.c: Buffer operations
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
25 * @short_description: Data-passing buffer type
26 * @see_also: #GstPad, #GstMiniObject, #GstMemory, #GstMeta, #GstBufferPool
28 * Buffers are the basic unit of data transfer in GStreamer. They contain the
29 * timing and offset along with other arbitrary metadata that is associated
30 * with the #GstMemory blocks that the buffer contains.
32 * Buffers are usually created with gst_buffer_new(). After a buffer has been
33 * created one will typically allocate memory for it and add it to the buffer.
34 * The following example creates a buffer that can hold a given video frame
35 * with a given width, height and bits per plane.
39 * gint size, width, height, bpp;
41 * size = width * height * bpp;
42 * buffer = gst_buffer_new ();
43 * memory = gst_allocator_alloc (NULL, size, NULL);
44 * gst_buffer_insert_memory (buffer, -1, memory);
48 * Alternatively, use gst_buffer_new_allocate() to create a buffer with
49 * preallocated data of a given size.
51 * Buffers can contain a list of #GstMemory objects. You can retrieve how many
52 * memory objects with gst_buffer_n_memory() and you can get a pointer
53 * to memory with gst_buffer_peek_memory()
55 * A buffer will usually have timestamps, and a duration, but neither of these
56 * are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
57 * meaningful value can be given for these, they should be set. The timestamps
58 * and duration are measured in nanoseconds (they are #GstClockTime values).
60 * The buffer DTS refers to the timestamp when the buffer should be decoded and
61 * is usually monotonically increasing. The buffer PTS refers to the timestamp when
62 * the buffer content should be presented to the user and is not always
63 * monotonically increasing.
65 * A buffer can also have one or both of a start and an end offset. These are
66 * media-type specific. For video buffers, the start offset will generally be
67 * the frame number. For audio buffers, it will be the number of samples
68 * produced so far. For compressed data, it could be the byte offset in a
69 * source or destination file. Likewise, the end offset will be the offset of
70 * the end of the buffer. These can only be meaningfully interpreted if you
71 * know the media type of the buffer (the preceding CAPS event). Either or both
72 * can be set to #GST_BUFFER_OFFSET_NONE.
74 * gst_buffer_ref() is used to increase the refcount of a buffer. This must be
75 * done when you want to keep a handle to the buffer after pushing it to the
76 * next element. The buffer refcount determines the writability of the buffer, a
77 * buffer is only writable when the refcount is exactly 1, i.e. when the caller
78 * has the only reference to the buffer.
80 * To efficiently create a smaller buffer out of an existing one, you can
81 * use gst_buffer_copy_region(). This method tries to share the memory objects
82 * between the two buffers.
84 * If a plug-in wants to modify the buffer data or metadata in-place, it should
85 * first obtain a buffer that is safe to modify by using
86 * gst_buffer_make_writable(). This function is optimized so that a copy will
87 * only be made when it is necessary.
89 * Several flags of the buffer can be set and unset with the
90 * GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
91 * GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlags flag is set.
93 * Buffers can be efficiently merged into a larger buffer with
94 * gst_buffer_append(). Copying of memory will only be done when absolutely
97 * Arbitrary extra metadata can be set on a buffer with gst_buffer_add_meta().
98 * Metadata can be retrieved with gst_buffer_get_meta(). See also #GstMeta
100 * An element should either unref the buffer or push it out on a src pad
101 * using gst_pad_push() (see #GstPad).
103 * Buffers are usually freed by unreffing them with gst_buffer_unref(). When
104 * the refcount drops to 0, any memory and metadata pointed to by the buffer is
105 * unreffed as well. Buffers allocated from a #GstBufferPool will be returned to
106 * the pool when the refcount drops to 0.
108 #include "gst_private.h"
117 #include "gstbuffer.h"
118 #include "gstbufferpool.h"
120 #include "gstutils.h"
121 #include "gstversion.h"
123 GType _gst_buffer_type = 0;
125 typedef struct _GstMetaItem GstMetaItem;
132 #define ITEM_SIZE(info) ((info)->size + sizeof (GstMetaItem))
134 #define GST_BUFFER_MEM_MAX 16
136 #define GST_BUFFER_SLICE_SIZE(b) (((GstBufferImpl *)(b))->slice_size)
137 #define GST_BUFFER_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
138 #define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
139 #define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
140 #define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
141 #define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
149 /* the memory blocks */
151 GstMemory *mem[GST_BUFFER_MEM_MAX];
153 /* memory of the buffer when allocated from 1 chunk */
156 /* FIXME, make metadata allocation more efficient by using part of the
163 _is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
165 GstMemory *mcur, *mprv;
166 gboolean have_offset = FALSE;
171 for (i = 0; i < len; i++) {
179 /* check if memory is contiguous */
180 if (!gst_memory_is_span (mprv, mcur, &poffs))
187 *parent = mprv->parent;
197 _get_merged_memory (GstBuffer * buffer, guint idx, guint length)
199 GstMemory **mem, *result = NULL;
201 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %u", buffer, idx,
204 mem = GST_BUFFER_MEM_ARRAY (buffer);
206 if (G_UNLIKELY (length == 0)) {
208 } else if (G_LIKELY (length == 1)) {
209 result = gst_memory_ref (mem[idx]);
211 GstMemory *parent = NULL;
212 gsize size, poffset = 0;
214 size = gst_buffer_get_sizes_range (buffer, idx, length, NULL, NULL);
216 if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
217 if (!GST_MEMORY_IS_NO_SHARE (parent))
218 result = gst_memory_share (parent, poffset, size);
220 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
221 result = gst_memory_copy (parent, poffset, size);
224 gsize i, tocopy, left;
225 GstMapInfo sinfo, dinfo;
228 result = gst_allocator_alloc (NULL, size, NULL);
229 gst_memory_map (result, &dinfo, GST_MAP_WRITE);
234 for (i = idx; i < (idx + length) && left > 0; i++) {
235 gst_memory_map (mem[i], &sinfo, GST_MAP_READ);
236 tocopy = MIN (sinfo.size, left);
237 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
238 "memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
239 tocopy, result, mem[i]);
240 memcpy (ptr, (guint8 *) sinfo.data, tocopy);
243 gst_memory_unmap (mem[i], &sinfo);
245 gst_memory_unmap (result, &dinfo);
252 _replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
259 GST_CAT_LOG (GST_CAT_BUFFER,
260 "buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
263 /* unref old memory */
264 for (i = idx; i < end; i++) {
265 GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
267 gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
268 gst_memory_unref (old);
272 /* replace with single memory */
273 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
274 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
280 memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
281 &GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
283 GST_BUFFER_MEM_LEN (buffer) = len - length;
284 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
288 _memory_add (GstBuffer * buffer, gint idx, GstMemory * mem, gboolean lock)
290 guint i, len = GST_BUFFER_MEM_LEN (buffer);
292 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p, lock %d", buffer,
295 if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
296 /* too many buffer, span them. */
297 /* FIXME, there is room for improvement here: We could only try to merge
298 * 2 buffers to make some room. If we can't efficiently merge 2 buffers we
299 * could try to only merge the two smallest buffers to avoid memcpy, etc. */
300 GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
302 _replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
303 /* we now have 1 single spanned buffer */
310 for (i = len; i > idx; i--) {
311 /* move buffers to insert, FIXME, we need to insert first and then merge */
312 GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
314 /* and insert the new buffer */
316 gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
317 GST_BUFFER_MEM_PTR (buffer, idx) = mem;
318 GST_BUFFER_MEM_LEN (buffer) = len + 1;
320 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
323 GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
326 _priv_gst_buffer_initialize (void)
328 _gst_buffer_type = gst_buffer_get_type ();
332 * gst_buffer_get_max_memory:
334 * Get the maximum amount of memory blocks that a buffer can hold. This is a
335 * compile time constant that can be queried with the function.
337 * When more memory blocks are added, existing memory blocks will be merged
338 * together to make room for the new block.
340 * Returns: the maximum amount of memory blocks that a buffer can hold.
345 gst_buffer_get_max_memory (void)
347 return GST_BUFFER_MEM_MAX;
351 * gst_buffer_copy_into:
352 * @dest: a destination #GstBuffer
353 * @src: a source #GstBuffer
354 * @flags: flags indicating what metadata fields should be copied.
355 * @offset: offset to copy from
356 * @size: total size to copy. If -1, all data is copied.
358 * Copies the information from @src into @dest.
360 * If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
361 * the memory from @src will be appended to @dest.
363 * @flags indicate which fields will be copied.
365 * Returns: %TRUE if the copying succeeded, %FALSE otherwise.
368 gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
369 GstBufferCopyFlags flags, gsize offset, gsize size)
373 gboolean region = FALSE;
375 g_return_val_if_fail (dest != NULL, FALSE);
376 g_return_val_if_fail (src != NULL, FALSE);
378 /* nothing to copy if the buffers are the same */
379 if (G_UNLIKELY (dest == src))
382 g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
384 bufsize = gst_buffer_get_size (src);
385 g_return_val_if_fail (bufsize >= offset, FALSE);
389 size = bufsize - offset;
392 g_return_val_if_fail (bufsize >= offset + size, FALSE);
394 GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
395 "-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
398 if (flags & GST_BUFFER_COPY_FLAGS) {
400 guint flags_mask = ~GST_BUFFER_FLAG_TAG_MEMORY;
402 GST_MINI_OBJECT_FLAGS (dest) =
403 (GST_MINI_OBJECT_FLAGS (src) & flags_mask) |
404 (GST_MINI_OBJECT_FLAGS (dest) & ~flags_mask);
407 if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
409 GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
410 GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
411 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
412 if (size == bufsize) {
413 GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
414 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
417 GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
418 GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
419 GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
420 GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
421 GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
425 if (flags & GST_BUFFER_COPY_MEMORY) {
426 gsize skip, left, len, dest_len, i, bsize;
429 deep = flags & GST_BUFFER_COPY_DEEP;
431 len = GST_BUFFER_MEM_LEN (src);
432 dest_len = GST_BUFFER_MEM_LEN (dest);
436 /* copy and make regions of the memory */
437 for (i = 0; i < len && left > 0; i++) {
438 GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
440 bsize = gst_memory_get_sizes (mem, NULL, NULL);
443 /* don't copy buffer */
446 GstMemory *newmem = NULL;
449 tocopy = MIN (bsize - skip, left);
451 if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
452 /* we need to clip something */
453 newmem = gst_memory_share (mem, skip, tocopy);
458 if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
459 /* deep copy or we're not allowed to share this memory
460 * between buffers, always copy then */
461 newmem = gst_memory_copy (mem, skip, tocopy);
463 } else if (!newmem) {
464 newmem = gst_memory_ref (mem);
468 gst_buffer_remove_memory_range (dest, dest_len, -1);
472 _memory_add (dest, -1, newmem, TRUE);
476 if (flags & GST_BUFFER_COPY_MERGE) {
479 len = GST_BUFFER_MEM_LEN (dest);
480 mem = _get_merged_memory (dest, 0, len);
482 gst_buffer_remove_memory_range (dest, dest_len, -1);
485 _replace_memory (dest, len, 0, len, mem);
489 if (flags & GST_BUFFER_COPY_META) {
490 /* NOTE: GstGLSyncMeta copying relies on the meta
491 * being copied now, after the buffer data,
492 * so this has to happen last */
493 for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
494 GstMeta *meta = &walk->meta;
495 const GstMetaInfo *info = meta->info;
497 if (info->transform_func) {
498 GstMetaTransformCopy copy_data;
500 copy_data.region = region;
501 copy_data.offset = offset;
502 copy_data.size = size;
504 if (!info->transform_func (dest, meta, src,
505 _gst_meta_transform_copy, ©_data)) {
506 GST_CAT_ERROR (GST_CAT_BUFFER,
507 "failed to copy meta %p of API type %s", meta,
508 g_type_name (info->api));
518 gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
522 g_return_val_if_fail (buffer != NULL, NULL);
524 /* create a fresh new buffer */
525 copy = gst_buffer_new ();
527 /* copy what the 'flags' want from our parent */
528 /* FIXME why we can't pass const to gst_buffer_copy_into() ? */
529 if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
530 gst_buffer_replace (©, NULL);
533 GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
539 _gst_buffer_copy (const GstBuffer * buffer)
541 return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
545 * gst_buffer_copy_deep:
546 * @buf: a #GstBuffer.
548 * Create a copy of the given buffer. This will make a newly allocated
549 * copy of the data the source buffer contains.
551 * Returns: (transfer full): a new copy of @buf.
554 gst_buffer_copy_deep (const GstBuffer * buffer)
556 return gst_buffer_copy_with_flags (buffer,
557 GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
560 /* the default dispose function revives the buffer and returns it to the
561 * pool when there is a pool */
563 _gst_buffer_dispose (GstBuffer * buffer)
567 /* no pool, do free */
568 if ((pool = buffer->pool) == NULL)
571 /* keep the buffer alive */
572 gst_buffer_ref (buffer);
573 /* return the buffer to the pool */
574 GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
575 gst_buffer_pool_release_buffer (pool, buffer);
581 _gst_buffer_free (GstBuffer * buffer)
583 GstMetaItem *walk, *next;
587 g_return_if_fail (buffer != NULL);
589 GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
592 for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
593 GstMeta *meta = &walk->meta;
594 const GstMetaInfo *info = meta->info;
596 /* call free_func if any */
598 info->free_func (meta, buffer);
601 /* and free the slice */
602 g_slice_free1 (ITEM_SIZE (info), walk);
605 /* get the size, when unreffing the memory, we could also unref the buffer
607 msize = GST_BUFFER_SLICE_SIZE (buffer);
609 /* free our memory */
610 len = GST_BUFFER_MEM_LEN (buffer);
611 for (i = 0; i < len; i++) {
612 gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
613 gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
616 /* we set msize to 0 when the buffer is part of the memory block */
619 memset (buffer, 0xff, msize);
621 g_slice_free1 (msize, buffer);
623 gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
628 gst_buffer_init (GstBufferImpl * buffer, gsize size)
630 gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
631 (GstMiniObjectCopyFunction) _gst_buffer_copy,
632 (GstMiniObjectDisposeFunction) _gst_buffer_dispose,
633 (GstMiniObjectFreeFunction) _gst_buffer_free);
635 GST_BUFFER_SLICE_SIZE (buffer) = size;
637 GST_BUFFER (buffer)->pool = NULL;
638 GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
639 GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
640 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
641 GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
642 GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
644 GST_BUFFER_MEM_LEN (buffer) = 0;
645 GST_BUFFER_META (buffer) = NULL;
651 * Creates a newly allocated buffer without any data.
655 * Returns: (transfer full): the new #GstBuffer.
658 gst_buffer_new (void)
660 GstBufferImpl *newbuf;
662 newbuf = g_slice_new (GstBufferImpl);
663 GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
665 gst_buffer_init (newbuf, sizeof (GstBufferImpl));
667 return GST_BUFFER_CAST (newbuf);
671 * gst_buffer_new_allocate:
672 * @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
674 * @size: the size in bytes of the new buffer's data.
675 * @params: (transfer none) (allow-none): optional parameters
677 * Tries to create a newly allocated buffer with data of the given size and
678 * extra parameters from @allocator. If the requested amount of memory can't be
679 * allocated, %NULL will be returned. The allocated buffer memory is not cleared.
681 * When @allocator is %NULL, the default memory allocator will be used.
683 * Note that when @size == 0, the buffer will not have memory associated with it.
687 * Returns: (transfer full) (nullable): a new #GstBuffer, or %NULL if
688 * the memory couldn't be allocated.
691 gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
692 GstAllocationParams * params)
703 mem = gst_allocator_alloc (allocator, size, params);
704 if (G_UNLIKELY (mem == NULL))
710 newbuf = gst_buffer_new ();
713 _memory_add (newbuf, -1, mem, TRUE);
715 GST_CAT_LOG (GST_CAT_BUFFER,
716 "new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
721 asize = sizeof (GstBufferImpl) + size;
722 data = g_slice_alloc (asize);
723 if (G_UNLIKELY (data == NULL))
726 newbuf = GST_BUFFER_CAST (data);
728 gst_buffer_init ((GstBufferImpl *) data, asize);
730 mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
732 _memory_add (newbuf, -1, mem, TRUE);
737 /* allocate memory and buffer, it might be interesting to do this but there
738 * are many complications. We need to keep the memory mapped to access the
739 * buffer fields and the memory for the buffer might be just very slow. We
740 * also need to do some more magic to get the alignment right. */
741 asize = sizeof (GstBufferImpl) + size;
742 mem = gst_allocator_alloc (allocator, asize, align);
743 if (G_UNLIKELY (mem == NULL))
746 /* map the data part and init the buffer in it, set the buffer size to 0 so
747 * that a finalize won't free the buffer */
748 data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
749 gst_buffer_init ((GstBufferImpl *) data, 0);
750 gst_memory_unmap (mem);
752 /* strip off the buffer */
753 gst_memory_resize (mem, sizeof (GstBufferImpl), size);
755 newbuf = GST_BUFFER_CAST (data);
756 GST_BUFFER_BUFMEM (newbuf) = mem;
759 _memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
761 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
768 GST_CAT_WARNING (GST_CAT_BUFFER,
769 "failed to allocate %" G_GSIZE_FORMAT " bytes", size);
775 * gst_buffer_new_wrapped_full:
776 * @flags: #GstMemoryFlags
777 * @data: (array length=size) (element-type guint8) (transfer none): data to wrap
778 * @maxsize: allocated size of @data
779 * @offset: offset in @data
780 * @size: size of valid data
781 * @user_data: (allow-none): user_data
782 * @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
784 * Allocate a new buffer that wraps the given memory. @data must point to
785 * @maxsize of memory, the wrapped buffer will have the region from @offset and
788 * When the buffer is destroyed, @notify will be called with @user_data.
790 * The prefix/padding must be filled with 0 if @flags contains
791 * #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
793 * Returns: (transfer full): a new #GstBuffer
796 gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
797 gsize maxsize, gsize offset, gsize size, gpointer user_data,
798 GDestroyNotify notify)
803 newbuf = gst_buffer_new ();
805 gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
807 _memory_add (newbuf, -1, mem, TRUE);
808 GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
814 * gst_buffer_new_wrapped:
815 * @data: (array length=size) (element-type guint8) (transfer full): data to wrap
816 * @size: allocated size of @data
818 * Creates a new buffer that wraps the given @data. The memory will be freed
819 * with g_free and will be marked writable.
823 * Returns: (transfer full): a new #GstBuffer
826 gst_buffer_new_wrapped (gpointer data, gsize size)
828 return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
832 * gst_buffer_n_memory:
833 * @buffer: a #GstBuffer.
835 * Get the amount of memory blocks that this buffer has. This amount is never
836 * larger than what gst_buffer_get_max_memory() returns.
838 * Returns: (transfer full): the amount of memory block in this buffer.
841 gst_buffer_n_memory (GstBuffer * buffer)
843 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
845 return GST_BUFFER_MEM_LEN (buffer);
849 * gst_buffer_prepend_memory:
850 * @buffer: a #GstBuffer.
851 * @mem: (transfer full): a #GstMemory.
853 * Prepend the memory block @mem to @buffer. This function takes
854 * ownership of @mem and thus doesn't increase its refcount.
856 * This function is identical to gst_buffer_insert_memory() with an index of 0.
857 * See gst_buffer_insert_memory() for more details.
860 gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
862 gst_buffer_insert_memory (buffer, 0, mem);
866 * gst_buffer_append_memory:
867 * @buffer: a #GstBuffer.
868 * @mem: (transfer full): a #GstMemory.
870 * Append the memory block @mem to @buffer. This function takes
871 * ownership of @mem and thus doesn't increase its refcount.
873 * This function is identical to gst_buffer_insert_memory() with an index of -1.
874 * See gst_buffer_insert_memory() for more details.
877 gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
879 gst_buffer_insert_memory (buffer, -1, mem);
883 * gst_buffer_insert_memory:
884 * @buffer: a #GstBuffer.
885 * @idx: the index to add the memory at, or -1 to append it to the end
886 * @mem: (transfer full): a #GstMemory.
888 * Insert the memory block @mem to @buffer at @idx. This function takes ownership
889 * of @mem and thus doesn't increase its refcount.
891 * Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
892 * added, existing memory blocks will automatically be merged to make room for
896 gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
898 g_return_if_fail (GST_IS_BUFFER (buffer));
899 g_return_if_fail (gst_buffer_is_writable (buffer));
900 g_return_if_fail (mem != NULL);
901 g_return_if_fail (idx == -1 ||
902 (idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
904 _memory_add (buffer, idx, mem, TRUE);
908 _get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
911 GstMemory *mem, *mapped;
913 mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
915 mapped = gst_memory_make_mapped (mem, info, flags);
918 /* memory changed, lock new memory */
919 gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
920 GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
921 /* unlock old memory */
922 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
923 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
925 gst_memory_unref (mem);
931 * gst_buffer_peek_memory:
932 * @buffer: a #GstBuffer.
935 * Get the memory block at @idx in @buffer. The memory block stays valid until
936 * the memory block in @buffer is removed, replaced or merged, typically with
937 * any call that modifies the memory in @buffer.
939 * Returns: (transfer none): the #GstMemory at @idx.
942 gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
946 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
947 len = GST_BUFFER_MEM_LEN (buffer);
948 g_return_val_if_fail (idx < len, NULL);
950 return GST_BUFFER_MEM_PTR (buffer, idx);
954 * gst_buffer_get_memory:
955 * @buffer: a #GstBuffer.
958 * Get the memory block at index @idx in @buffer.
960 * Returns: (transfer full): a #GstMemory that contains the data of the
961 * memory block at @idx. Use gst_memory_unref () after usage.
964 gst_buffer_get_memory (GstBuffer * buffer, guint idx)
966 return gst_buffer_get_memory_range (buffer, idx, 1);
970 * gst_buffer_get_all_memory:
971 * @buffer: a #GstBuffer.
973 * Get all the memory block in @buffer. The memory blocks will be merged
974 * into one large #GstMemory.
976 * Returns: (transfer full): a #GstMemory that contains the merged memory.
977 * Use gst_memory_unref () after usage.
980 gst_buffer_get_all_memory (GstBuffer * buffer)
982 return gst_buffer_get_memory_range (buffer, 0, -1);
986 * gst_buffer_get_memory_range:
987 * @buffer: a #GstBuffer.
991 * Get @length memory blocks in @buffer starting at @idx. The memory blocks will
992 * be merged into one large #GstMemory.
994 * If @length is -1, all memory starting from @idx is merged.
996 * Returns: (transfer full): a #GstMemory that contains the merged data of @length
997 * blocks starting at @idx. Use gst_memory_unref () after usage.
1000 gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
1004 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1006 g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
1007 len = GST_BUFFER_MEM_LEN (buffer);
1008 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1009 (length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
1014 return _get_merged_memory (buffer, idx, length);
1018 * gst_buffer_replace_memory:
1019 * @buffer: a #GstBuffer.
1021 * @mem: (transfer full): a #GstMemory
1023 * Replaces the memory block at index @idx in @buffer with @mem.
1026 gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
1028 gst_buffer_replace_memory_range (buffer, idx, 1, mem);
1032 * gst_buffer_replace_all_memory:
1033 * @buffer: a #GstBuffer.
1034 * @mem: (transfer full): a #GstMemory
1036 * Replaces all memory in @buffer with @mem.
1039 gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
1041 gst_buffer_replace_memory_range (buffer, 0, -1, mem);
1045 * gst_buffer_replace_memory_range:
1046 * @buffer: a #GstBuffer.
1048 * @length: a length should not be 0
1049 * @mem: (transfer full): a #GstMemory
1051 * Replaces @length memory blocks in @buffer starting at @idx with @mem.
1053 * If @length is -1, all memory starting from @idx will be removed and
1054 * replaced with @mem.
1056 * @buffer should be writable.
1059 gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
1064 g_return_if_fail (GST_IS_BUFFER (buffer));
1065 g_return_if_fail (gst_buffer_is_writable (buffer));
1067 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
1069 len = GST_BUFFER_MEM_LEN (buffer);
1070 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1071 (length == -1 && idx < len) || (length > 0 && length + idx <= len));
1076 _replace_memory (buffer, len, idx, length, mem);
1080 * gst_buffer_remove_memory:
1081 * @buffer: a #GstBuffer.
1084 * Remove the memory block in @b at index @i.
1087 gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
1089 gst_buffer_remove_memory_range (buffer, idx, 1);
1093 * gst_buffer_remove_all_memory:
1094 * @buffer: a #GstBuffer.
1096 * Remove all the memory blocks in @buffer.
1099 gst_buffer_remove_all_memory (GstBuffer * buffer)
1101 gst_buffer_remove_memory_range (buffer, 0, -1);
1105 * gst_buffer_remove_memory_range:
1106 * @buffer: a #GstBuffer.
1110 * Remove @length memory blocks in @buffer starting from @idx.
1112 * @length can be -1, in which case all memory starting from @idx is removed.
1115 gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
1119 g_return_if_fail (GST_IS_BUFFER (buffer));
1120 g_return_if_fail (gst_buffer_is_writable (buffer));
1122 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1124 len = GST_BUFFER_MEM_LEN (buffer);
1125 g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
1126 (length == -1 && idx < len) || length + idx <= len);
1131 _replace_memory (buffer, len, idx, length, NULL);
1135 * gst_buffer_find_memory:
1136 * @buffer: a #GstBuffer.
1137 * @offset: an offset
1139 * @idx: (out): pointer to index
1140 * @length: (out): pointer to length
1141 * @skip: (out): pointer to skip
1143 * Find the memory blocks that span @size bytes starting from @offset
1146 * When this function returns %TRUE, @idx will contain the index of the first
1147 * memory block where the byte for @offset can be found and @length contains the
1148 * number of memory blocks containing the @size remaining bytes. @skip contains
1149 * the number of bytes to skip in the memory block at @idx to get to the byte
1152 * @size can be -1 to get all the memory blocks after @idx.
1154 * Returns: %TRUE when @size bytes starting from @offset could be found in
1155 * @buffer and @idx, @length and @skip will be filled.
1158 gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
1159 guint * idx, guint * length, gsize * skip)
1161 guint i, len, found;
1163 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1164 g_return_val_if_fail (idx != NULL, FALSE);
1165 g_return_val_if_fail (length != NULL, FALSE);
1166 g_return_val_if_fail (skip != NULL, FALSE);
1168 len = GST_BUFFER_MEM_LEN (buffer);
1171 for (i = 0; i < len; i++) {
1175 mem = GST_BUFFER_MEM_PTR (buffer, i);
1176 s = gst_memory_get_sizes (mem, NULL, NULL);
1179 /* block before offset, or empty block, skip */
1182 /* block after offset */
1184 /* first block, remember index and offset */
1188 /* return remaining blocks */
1195 /* count the amount of found bytes */
1197 if (found >= size) {
1198 /* we have enough bytes */
1199 *length = i - *idx + 1;
1208 * gst_buffer_is_memory_range_writable:
1209 * @buffer: a #GstBuffer.
1211 * @length: a length should not be 0
1213 * Check if @length memory blocks in @buffer starting from @idx are writable.
1215 * @length can be -1 to check all the memory blocks after @idx.
1217 * Note that this function does not check if @buffer is writable, use
1218 * gst_buffer_is_writable() to check that if needed.
1220 * Returns: %TRUE if the memory range is writable
1225 gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
1229 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1231 GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
1233 len = GST_BUFFER_MEM_LEN (buffer);
1234 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1235 (length == -1 && idx < len) || (length > 0 && length + idx <= len),
1243 for (i = 0; i < len; i++) {
1244 if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
1251 * gst_buffer_is_all_memory_writable:
1252 * @buffer: a #GstBuffer.
1254 * Check if all memory blocks in @buffer are writable.
1256 * Note that this function does not check if @buffer is writable, use
1257 * gst_buffer_is_writable() to check that if needed.
1259 * Returns: %TRUE if all memory blocks in @buffer are writable
1264 gst_buffer_is_all_memory_writable (GstBuffer * buffer)
1266 return gst_buffer_is_memory_range_writable (buffer, 0, -1);
1270 * gst_buffer_get_sizes:
1271 * @buffer: a #GstBuffer.
1272 * @offset: (out) (allow-none): a pointer to the offset
1273 * @maxsize: (out) (allow-none): a pointer to the maxsize
1275 * Get the total size of the memory blocks in @b.
1277 * When not %NULL, @offset will contain the offset of the data in the
1278 * first memory block in @buffer and @maxsize will contain the sum of
1279 * the size and @offset and the amount of extra padding on the last
1280 * memory block. @offset and @maxsize can be used to resize the
1281 * buffer memory blocks with gst_buffer_resize().
1283 * Returns: total size of the memory blocks in @buffer.
1286 gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
1288 return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
1292 * gst_buffer_get_size:
1293 * @buffer: a #GstBuffer.
1295 * Get the total size of the memory blocks in @buffer.
1297 * Returns: total size of the memory blocks in @buffer.
1300 gst_buffer_get_size (GstBuffer * buffer)
1302 return gst_buffer_get_sizes_range (buffer, 0, -1, NULL, NULL);
1306 * gst_buffer_get_sizes_range:
1307 * @buffer: a #GstBuffer.
1310 * @offset: (out) (allow-none): a pointer to the offset
1311 * @maxsize: (out) (allow-none): a pointer to the maxsize
1313 * Get the total size of @length memory blocks stating from @idx in @buffer.
1315 * When not %NULL, @offset will contain the offset of the data in the
1316 * memory block in @buffer at @idx and @maxsize will contain the sum of the size
1317 * and @offset and the amount of extra padding on the memory block at @idx +
1319 * @offset and @maxsize can be used to resize the buffer memory blocks with
1320 * gst_buffer_resize_range().
1322 * Returns: total size of @length memory blocks starting at @idx in @buffer.
1325 gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
1326 gsize * offset, gsize * maxsize)
1332 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1333 len = GST_BUFFER_MEM_LEN (buffer);
1334 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1335 (length == -1 && idx < len) || (length + idx <= len), 0);
1340 if (G_LIKELY (length == 1)) {
1342 mem = GST_BUFFER_MEM_PTR (buffer, idx);
1343 size = gst_memory_get_sizes (mem, offset, maxsize);
1349 size = offs = extra = 0;
1350 for (i = idx; i < end; i++) {
1353 mem = GST_BUFFER_MEM_PTR (buffer, i);
1354 s = gst_memory_get_sizes (mem, &o, &ms);
1358 /* first size, take accumulated data before as the offset */
1362 /* save the amount of data after this block */
1363 extra = ms - (o + s);
1365 /* empty block, add as extra */
1372 *maxsize = offs + size + extra;
1378 * gst_buffer_resize:
1379 * @buffer: a #GstBuffer.
1380 * @offset: the offset adjustment
1381 * @size: the new size or -1 to just adjust the offset
1383 * Set the offset and total size of the memory blocks in @buffer.
1386 gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
1388 gst_buffer_resize_range (buffer, 0, -1, offset, size);
1392 * gst_buffer_set_size:
1393 * @buffer: a #GstBuffer.
1394 * @size: the new size
1396 * Set the total size of the memory blocks in @buffer.
1399 gst_buffer_set_size (GstBuffer * buffer, gssize size)
1401 gst_buffer_resize_range (buffer, 0, -1, 0, size);
1405 * gst_buffer_resize_range:
1406 * @buffer: a #GstBuffer.
1409 * @offset: the offset adjustment
1410 * @size: the new size or -1 to just adjust the offset
1412 * Set the total size of the @length memory blocks starting at @idx in
1415 * Returns: %TRUE if resizing succeeded, %FALSE otherwise.
1418 gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
1419 gssize offset, gssize size)
1422 gsize bsize, bufsize, bufoffs, bufmax;
1424 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
1425 g_return_val_if_fail (size >= -1, FALSE);
1427 len = GST_BUFFER_MEM_LEN (buffer);
1428 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1429 (length == -1 && idx < len) || (length + idx <= len), FALSE);
1434 bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
1436 GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
1437 " size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
1438 G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
1440 /* we can't go back further than the current offset or past the end of the
1442 g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
1443 && bufoffs + offset <= bufmax), FALSE);
1445 g_return_val_if_fail (bufsize >= offset, FALSE);
1446 size = bufsize - offset;
1448 g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
1451 if (offset == 0 && size == bufsize)
1456 for (i = idx; i < end; i++) {
1460 mem = GST_BUFFER_MEM_PTR (buffer, i);
1461 bsize = gst_memory_get_sizes (mem, NULL, NULL);
1464 /* last buffer always gets resized to the remaining size */
1467 /* shrink buffers before the offset */
1468 else if ((gssize) bsize <= offset) {
1470 noffs = offset - bsize;
1473 /* clip other buffers */
1475 left = MIN (bsize - offset, size);
1477 if (offset != 0 || left != bsize) {
1478 if (gst_memory_is_writable (mem)) {
1479 gst_memory_resize (mem, offset, left);
1481 GstMemory *newmem = NULL;
1483 if (!GST_MEMORY_IS_NO_SHARE (mem))
1484 newmem = gst_memory_share (mem, offset, left);
1487 newmem = gst_memory_copy (mem, offset, left);
1492 gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
1493 GST_BUFFER_MEM_PTR (buffer, i) = newmem;
1494 gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
1495 gst_memory_unref (mem);
1497 GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
1510 * @buffer: a #GstBuffer.
1511 * @info: (out): info about the mapping
1512 * @flags: flags for the mapping
1514 * This function fills @info with the #GstMapInfo of all merged memory
1515 * blocks in @buffer.
1517 * @flags describe the desired access of the memory. When @flags is
1518 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1519 * gst_buffer_is_writable()).
1521 * When @buffer is writable but the memory isn't, a writable copy will
1522 * automatically be created and returned. The readonly copy of the
1523 * buffer memory will then also be replaced with this writable copy.
1525 * The memory in @info should be unmapped with gst_buffer_unmap() after
1528 * Returns: %TRUE if the map succeeded and @info contains valid data.
1531 gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
1533 return gst_buffer_map_range (buffer, 0, -1, info, flags);
1537 * gst_buffer_map_range:
1538 * @buffer: a #GstBuffer.
1541 * @info: (out): info about the mapping
1542 * @flags: flags for the mapping
1544 * This function fills @info with the #GstMapInfo of @length merged memory blocks
1545 * starting at @idx in @buffer. When @length is -1, all memory blocks starting
1546 * from @idx are merged and mapped.
1548 * @flags describe the desired access of the memory. When @flags is
1549 * #GST_MAP_WRITE, @buffer should be writable (as returned from
1550 * gst_buffer_is_writable()).
1552 * When @buffer is writable but the memory isn't, a writable copy will
1553 * automatically be created and returned. The readonly copy of the buffer memory
1554 * will then also be replaced with this writable copy.
1556 * The memory in @info should be unmapped with gst_buffer_unmap() after usage.
1558 * Returns: %TRUE if the map succeeded and @info contains valid
1562 gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
1563 GstMapInfo * info, GstMapFlags flags)
1565 GstMemory *mem, *nmem;
1566 gboolean write, writable;
1569 g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
1570 g_return_val_if_fail (info != NULL, FALSE);
1571 len = GST_BUFFER_MEM_LEN (buffer);
1572 g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
1573 (length == -1 && idx < len) || (length > 0
1574 && length + idx <= len), FALSE);
1576 GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
1577 buffer, idx, length, flags);
1579 write = (flags & GST_MAP_WRITE) != 0;
1580 writable = gst_buffer_is_writable (buffer);
1582 /* check if we can write when asked for write access */
1583 if (G_UNLIKELY (write && !writable))
1589 mem = _get_merged_memory (buffer, idx, length);
1590 if (G_UNLIKELY (mem == NULL))
1593 /* now try to map */
1594 nmem = gst_memory_make_mapped (mem, info, flags);
1595 if (G_UNLIKELY (nmem == NULL))
1598 /* if we merged or when the map returned a different memory, we try to replace
1599 * the memory in the buffer */
1600 if (G_UNLIKELY (length > 1 || nmem != mem)) {
1601 /* if the buffer is writable, replace the memory */
1603 _replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
1606 GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
1607 "temporary mapping for memory %p in buffer %p", nmem, buffer);
1616 GST_WARNING_OBJECT (buffer, "write map requested on non-writable buffer");
1617 g_critical ("write map requested on non-writable buffer");
1618 memset (info, 0, sizeof (GstMapInfo));
1623 /* empty buffer, we need to return NULL */
1624 GST_DEBUG_OBJECT (buffer, "can't get buffer memory");
1625 memset (info, 0, sizeof (GstMapInfo));
1630 GST_DEBUG_OBJECT (buffer, "cannot map memory");
1631 memset (info, 0, sizeof (GstMapInfo));
1638 * @buffer: a #GstBuffer.
1639 * @info: a #GstMapInfo
1641 * Release the memory previously mapped with gst_buffer_map().
1644 gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
1646 g_return_if_fail (GST_IS_BUFFER (buffer));
1647 g_return_if_fail (info != NULL);
1649 /* we need to check for NULL, it is possible that we tried to map a buffer
1650 * without memory and we should be able to unmap that fine */
1651 if (G_LIKELY (info->memory)) {
1652 gst_memory_unmap (info->memory, info);
1653 gst_memory_unref (info->memory);
1659 * @buffer: a #GstBuffer.
1660 * @offset: the offset to fill
1661 * @src: (array length=size) (element-type guint8): the source address
1662 * @size: the size to fill
1664 * Copy @size bytes from @src to @buffer at @offset.
1666 * Returns: The amount of bytes copied. This value can be lower than @size
1667 * when @buffer did not contain enough data.
1670 gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
1674 const guint8 *ptr = src;
1676 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1677 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1678 g_return_val_if_fail (src != NULL || size == 0, 0);
1680 GST_CAT_LOG (GST_CAT_BUFFER,
1681 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1684 len = GST_BUFFER_MEM_LEN (buffer);
1687 for (i = 0; i < len && left > 0; i++) {
1692 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1693 if (info.size > offset) {
1694 /* we have enough */
1695 tocopy = MIN (info.size - offset, left);
1696 memcpy ((guint8 *) info.data + offset, ptr, tocopy);
1701 /* offset past buffer, skip */
1702 offset -= info.size;
1704 gst_memory_unmap (mem, &info);
1710 * gst_buffer_extract:
1711 * @buffer: a #GstBuffer.
1712 * @offset: the offset to extract
1713 * @dest: the destination address
1714 * @size: the size to extract
1716 * Copy @size bytes starting from @offset in @buffer to @dest.
1718 * Returns: The amount of bytes extracted. This value can be lower than @size
1719 * when @buffer did not contain enough data.
1722 gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
1727 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1728 g_return_val_if_fail (dest != NULL, 0);
1730 GST_CAT_LOG (GST_CAT_BUFFER,
1731 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1734 len = GST_BUFFER_MEM_LEN (buffer);
1737 for (i = 0; i < len && left > 0; i++) {
1742 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1743 if (info.size > offset) {
1744 /* we have enough */
1745 tocopy = MIN (info.size - offset, left);
1746 memcpy (ptr, (guint8 *) info.data + offset, tocopy);
1751 /* offset past buffer, skip */
1752 offset -= info.size;
1754 gst_memory_unmap (mem, &info);
1760 * gst_buffer_memcmp:
1761 * @buffer: a #GstBuffer.
1762 * @offset: the offset in @buffer
1763 * @mem: (array length=size) (element-type guint8): the memory to compare
1764 * @size: the size to compare
1766 * Compare @size bytes starting from @offset in @buffer with the memory in @mem.
1768 * Returns: 0 if the memory is equal.
1771 gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
1775 const guint8 *ptr = mem;
1778 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1779 g_return_val_if_fail (mem != NULL, 0);
1781 GST_CAT_LOG (GST_CAT_BUFFER,
1782 "buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
1785 if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
1788 len = GST_BUFFER_MEM_LEN (buffer);
1790 for (i = 0; i < len && size > 0 && res == 0; i++) {
1795 mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
1796 if (info.size > offset) {
1797 /* we have enough */
1798 tocmp = MIN (info.size - offset, size);
1799 res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
1804 /* offset past buffer, skip */
1805 offset -= info.size;
1807 gst_memory_unmap (mem, &info);
1813 * gst_buffer_memset:
1814 * @buffer: a #GstBuffer.
1815 * @offset: the offset in @buffer
1816 * @val: the value to set
1817 * @size: the size to set
1819 * Fill @buf with @size bytes with @val starting from @offset.
1821 * Returns: The amount of bytes filled. This value can be lower than @size
1822 * when @buffer did not contain enough data.
1825 gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
1829 g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
1830 g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
1832 GST_CAT_LOG (GST_CAT_BUFFER,
1833 "buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
1834 buffer, offset, val, size);
1836 len = GST_BUFFER_MEM_LEN (buffer);
1839 for (i = 0; i < len && left > 0; i++) {
1844 mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
1845 if (info.size > offset) {
1846 /* we have enough */
1847 toset = MIN (info.size - offset, left);
1848 memset ((guint8 *) info.data + offset, val, toset);
1852 /* offset past buffer, skip */
1853 offset -= info.size;
1855 gst_memory_unmap (mem, &info);
1861 * gst_buffer_copy_region:
1862 * @parent: a #GstBuffer.
1863 * @flags: the #GstBufferCopyFlags
1864 * @offset: the offset into parent #GstBuffer at which the new sub-buffer
1866 * @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
1869 * Creates a sub-buffer from @parent at @offset and @size.
1870 * This sub-buffer uses the actual memory space of the parent buffer.
1871 * This function will copy the offset and timestamp fields when the
1872 * offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
1873 * #GST_BUFFER_OFFSET_NONE.
1874 * If @offset equals 0 and @size equals the total size of @buffer, the
1875 * duration and offset end fields are also copied. If not they will be set
1876 * to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
1880 * Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
1884 gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
1885 gsize offset, gsize size)
1889 g_return_val_if_fail (buffer != NULL, NULL);
1891 /* create the new buffer */
1892 copy = gst_buffer_new ();
1894 GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
1895 "-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
1897 if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
1898 gst_buffer_replace (©, NULL);
1904 * gst_buffer_append:
1905 * @buf1: (transfer full): the first source #GstBuffer to append.
1906 * @buf2: (transfer full): the second source #GstBuffer to append.
1908 * Append all the memory from @buf2 to @buf1. The result buffer will contain a
1909 * concatenation of the memory of @buf1 and @buf2.
1911 * Returns: (transfer full): the new #GstBuffer that contains the memory
1912 * of the two source buffers.
1915 gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
1917 return gst_buffer_append_region (buf1, buf2, 0, -1);
1921 * gst_buffer_append_region:
1922 * @buf1: (transfer full): the first source #GstBuffer to append.
1923 * @buf2: (transfer full): the second source #GstBuffer to append.
1924 * @offset: the offset in @buf2
1925 * @size: the size or -1 of @buf2
1927 * Append @size bytes at @offset from @buf2 to @buf1. The result buffer will
1928 * contain a concatenation of the memory of @buf1 and the requested region of
1931 * Returns: (transfer full): the new #GstBuffer that contains the memory
1932 * of the two source buffers.
1935 gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
1940 g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
1941 g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
1943 buf1 = gst_buffer_make_writable (buf1);
1944 buf2 = gst_buffer_make_writable (buf2);
1946 gst_buffer_resize (buf2, offset, size);
1948 len = GST_BUFFER_MEM_LEN (buf2);
1949 for (i = 0; i < len; i++) {
1952 mem = GST_BUFFER_MEM_PTR (buf2, i);
1953 GST_BUFFER_MEM_PTR (buf2, i) = NULL;
1954 _memory_add (buf1, -1, mem, FALSE);
1957 GST_BUFFER_MEM_LEN (buf2) = 0;
1958 GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
1959 gst_buffer_unref (buf2);
1965 * gst_buffer_get_meta:
1966 * @buffer: a #GstBuffer
1967 * @api: the #GType of an API
1969 * Get the metadata for @api on buffer. When there is no such metadata, %NULL is
1970 * returned. If multiple metadata with the given @api are attached to this
1971 * buffer only the first one is returned. To handle multiple metadata with a
1972 * given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
1973 * and check the meta->info.api member for the API type.
1975 * Returns: (transfer none) (nullable): the metadata for @api on
1979 gst_buffer_get_meta (GstBuffer * buffer, GType api)
1982 GstMeta *result = NULL;
1984 g_return_val_if_fail (buffer != NULL, NULL);
1985 g_return_val_if_fail (api != 0, NULL);
1987 /* find GstMeta of the requested API */
1988 for (item = GST_BUFFER_META (buffer); item; item = item->next) {
1989 GstMeta *meta = &item->meta;
1990 if (meta->info->api == api) {
1999 * gst_buffer_add_meta:
2000 * @buffer: a #GstBuffer
2001 * @info: a #GstMetaInfo
2002 * @params: params for @info
2004 * Add metadata for @info to @buffer using the parameters in @params.
2006 * Returns: (transfer none): the metadata for the api in @info on @buffer.
2009 gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
2013 GstMeta *result = NULL;
2016 g_return_val_if_fail (buffer != NULL, NULL);
2017 g_return_val_if_fail (info != NULL, NULL);
2018 g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
2020 /* create a new slice */
2021 size = ITEM_SIZE (info);
2022 item = g_slice_alloc (size);
2023 result = &item->meta;
2024 result->info = info;
2025 result->flags = GST_META_FLAG_NONE;
2027 GST_CAT_DEBUG (GST_CAT_BUFFER,
2028 "alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
2029 g_type_name (info->type), info->size);
2031 /* call the init_func when needed */
2032 if (info->init_func)
2033 if (!info->init_func (result, params, buffer))
2036 /* and add to the list of metadata */
2037 item->next = GST_BUFFER_META (buffer);
2038 GST_BUFFER_META (buffer) = item;
2044 g_slice_free1 (size, item);
2050 * gst_buffer_remove_meta:
2051 * @buffer: a #GstBuffer
2054 * Remove the metadata for @meta on @buffer.
2056 * Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
2057 * metadata was on @buffer.
2060 gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
2062 GstMetaItem *walk, *prev;
2064 g_return_val_if_fail (buffer != NULL, FALSE);
2065 g_return_val_if_fail (meta != NULL, FALSE);
2066 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2067 g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
2070 /* find the metadata and delete */
2071 prev = GST_BUFFER_META (buffer);
2072 for (walk = prev; walk; walk = walk->next) {
2073 GstMeta *m = &walk->meta;
2075 const GstMetaInfo *info = meta->info;
2077 /* remove from list */
2078 if (GST_BUFFER_META (buffer) == walk)
2079 GST_BUFFER_META (buffer) = walk->next;
2081 prev->next = walk->next;
2082 /* call free_func if any */
2083 if (info->free_func)
2084 info->free_func (m, buffer);
2086 /* and free the slice */
2087 g_slice_free1 (ITEM_SIZE (info), walk);
2092 return walk != NULL;
2096 * gst_buffer_iterate_meta:
2097 * @buffer: a #GstBuffer
2098 * @state: an opaque state pointer
2100 * Retrieve the next #GstMeta after @current. If @state points
2101 * to %NULL, the first metadata is returned.
2103 * @state will be updated with an opaque state pointer
2105 * Returns: (transfer none) (nullable): The next #GstMeta or %NULL
2106 * when there are no more items.
2109 gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
2113 g_return_val_if_fail (buffer != NULL, NULL);
2114 g_return_val_if_fail (state != NULL, NULL);
2116 meta = (GstMetaItem **) state;
2118 /* state NULL, move to first item */
2119 *meta = GST_BUFFER_META (buffer);
2121 /* state !NULL, move to next item in list */
2122 *meta = (*meta)->next;
2125 return &(*meta)->meta;
2131 * gst_buffer_foreach_meta:
2132 * @buffer: a #GstBuffer
2133 * @func: (scope call): a #GstBufferForeachMetaFunc to call
2134 * @user_data: (closure): user data passed to @func
2136 * Call @func with @user_data for each meta in @buffer.
2138 * @func can modify the passed meta pointer or its contents. The return value
2139 * of @func define if this function returns or if the remaining metadata items
2140 * in the buffer should be skipped.
2142 * Returns: %FALSE when @func returned %FALSE for one of the metadata.
2145 gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
2148 GstMetaItem *walk, *prev, *next;
2149 gboolean res = TRUE;
2151 g_return_val_if_fail (buffer != NULL, FALSE);
2152 g_return_val_if_fail (func != NULL, FALSE);
2154 /* find the metadata and delete */
2155 prev = GST_BUFFER_META (buffer);
2156 for (walk = prev; walk; walk = next) {
2159 m = new = &walk->meta;
2162 res = func (buffer, &new, user_data);
2165 const GstMetaInfo *info = m->info;
2167 GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
2168 g_type_name (info->type));
2170 g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
2171 g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
2174 /* remove from list */
2175 if (GST_BUFFER_META (buffer) == walk)
2176 GST_BUFFER_META (buffer) = next;
2180 /* call free_func if any */
2181 if (info->free_func)
2182 info->free_func (m, buffer);
2184 /* and free the slice */
2185 g_slice_free1 (ITEM_SIZE (info), walk);
2194 * gst_buffer_extract_dup:
2195 * @buffer: a #GstBuffer
2196 * @offset: the offset to extract
2197 * @size: the size to extract
2198 * @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
2199 * the destination array will be written.
2200 * @dest_size: (out): A location where the size of @dest can be written
2202 * Extracts a copy of at most @size bytes the data at @offset into a #GBytes.
2203 * @dest must be freed using g_free() when done.
2209 gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
2210 gpointer * dest, gsize * dest_size)
2214 real_size = gst_buffer_get_size (buffer);
2216 *dest = g_malloc (MIN (real_size - offset, size));
2218 *dest_size = gst_buffer_extract (buffer, offset, *dest, size);