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gstreamer/gst/gstbuffer.c
Mathieu Duponchelle d28fb55873 docs: standardize GstBuffer documentation 
* Don't mention explicitly that API is MT safe, this implies that
  other API is not. GStreamer API is assumed to be MT safe, thread
  safety should only be explicitly mentioned when API is *not* MT safe

* Don't repeat what annotations are stating with respect to ownership
  transfer, nullability

* Document enumeration members in standalone comments, so that their
  Since tag is accounted for by gobject-introspection

* Misc cleanup / typo fixes / addition of links

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/748>
2021-02-05 14:56:12 +01:00

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstbuffer.c: Buffer operations
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstbuffer
* @title: GstBuffer
* @short_description: Data-passing buffer type
* @see_also: #GstPad, #GstMiniObject, #GstMemory, #GstMeta, #GstBufferPool
*
* Buffers are the basic unit of data transfer in GStreamer. They contain the
* timing and offset along with other arbitrary metadata that is associated
* with the #GstMemory blocks that the buffer contains.
*
* Buffers are usually created with gst_buffer_new(). After a buffer has been
* created one will typically allocate memory for it and add it to the buffer.
* The following example creates a buffer that can hold a given video frame
* with a given width, height and bits per plane.
*
* ``` C
* GstBuffer *buffer;
* GstMemory *memory;
* gint size, width, height, bpp;
* ...
* size = width * height * bpp;
* buffer = gst_buffer_new ();
* memory = gst_allocator_alloc (NULL, size, NULL);
* gst_buffer_insert_memory (buffer, -1, memory);
* ...
* ```
*
* Alternatively, use gst_buffer_new_allocate() to create a buffer with
* preallocated data of a given size.
*
* Buffers can contain a list of #GstMemory objects. You can retrieve how many
* memory objects with gst_buffer_n_memory() and you can get a pointer
* to memory with gst_buffer_peek_memory()
*
* A buffer will usually have timestamps, and a duration, but neither of these
* are guaranteed (they may be set to #GST_CLOCK_TIME_NONE). Whenever a
* meaningful value can be given for these, they should be set. The timestamps
* and duration are measured in nanoseconds (they are #GstClockTime values).
*
* The buffer DTS refers to the timestamp when the buffer should be decoded and
* is usually monotonically increasing. The buffer PTS refers to the timestamp when
* the buffer content should be presented to the user and is not always
* monotonically increasing.
*
* A buffer can also have one or both of a start and an end offset. These are
* media-type specific. For video buffers, the start offset will generally be
* the frame number. For audio buffers, it will be the number of samples
* produced so far. For compressed data, it could be the byte offset in a
* source or destination file. Likewise, the end offset will be the offset of
* the end of the buffer. These can only be meaningfully interpreted if you
* know the media type of the buffer (the preceding CAPS event). Either or both
* can be set to #GST_BUFFER_OFFSET_NONE.
*
* gst_buffer_ref() is used to increase the refcount of a buffer. This must be
* done when you want to keep a handle to the buffer after pushing it to the
* next element. The buffer refcount determines the writability of the buffer, a
* buffer is only writable when the refcount is exactly 1, i.e. when the caller
* has the only reference to the buffer.
*
* To efficiently create a smaller buffer out of an existing one, you can
* use gst_buffer_copy_region(). This method tries to share the memory objects
* between the two buffers.
*
* If a plug-in wants to modify the buffer data or metadata in-place, it should
* first obtain a buffer that is safe to modify by using
* gst_buffer_make_writable(). This function is optimized so that a copy will
* only be made when it is necessary.
*
* Several flags of the buffer can be set and unset with the
* GST_BUFFER_FLAG_SET() and GST_BUFFER_FLAG_UNSET() macros. Use
* GST_BUFFER_FLAG_IS_SET() to test if a certain #GstBufferFlags flag is set.
*
* Buffers can be efficiently merged into a larger buffer with
* gst_buffer_append(). Copying of memory will only be done when absolutely
* needed.
*
* Arbitrary extra metadata can be set on a buffer with gst_buffer_add_meta().
* Metadata can be retrieved with gst_buffer_get_meta(). See also #GstMeta.
*
* An element should either unref the buffer or push it out on a src pad
* using gst_pad_push() (see #GstPad).
*
* Buffers are usually freed by unreffing them with gst_buffer_unref(). When
* the refcount drops to 0, any memory and metadata pointed to by the buffer is
* unreffed as well. Buffers allocated from a #GstBufferPool will be returned to
* the pool when the refcount drops to 0.
*
* The #GstParentBufferMeta is a meta which can be attached to a #GstBuffer
* to hold a reference to another buffer that is only released when the child
* #GstBuffer is released.
*
* Typically, #GstParentBufferMeta is used when the child buffer is directly
* using the #GstMemory of the parent buffer, and wants to prevent the parent
* buffer from being returned to a buffer pool until the #GstMemory is available
* for re-use. (Since: 1.6)
*/
#define GST_DISABLE_MINIOBJECT_INLINE_FUNCTIONS
#include "gst_private.h"
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include "gstbuffer.h"
#include "gstbufferpool.h"
#include "gstinfo.h"
#include "gstutils.h"
#include "gstversion.h"
GType _gst_buffer_type = 0;
/* info->size will be sizeof(FooMeta) which contains a GstMeta at the beginning
* too, and then there is again a GstMeta in GstMetaItem, so subtract one. */
#define ITEM_SIZE(info) ((info)->size + sizeof (GstMetaItem) - sizeof (GstMeta))
#define GST_BUFFER_MEM_MAX 16
#define GST_BUFFER_SLICE_SIZE(b) (((GstBufferImpl *)(b))->slice_size)
#define GST_BUFFER_MEM_LEN(b) (((GstBufferImpl *)(b))->len)
#define GST_BUFFER_MEM_ARRAY(b) (((GstBufferImpl *)(b))->mem)
#define GST_BUFFER_MEM_PTR(b,i) (((GstBufferImpl *)(b))->mem[i])
#define GST_BUFFER_BUFMEM(b) (((GstBufferImpl *)(b))->bufmem)
#define GST_BUFFER_META(b) (((GstBufferImpl *)(b))->item)
#define GST_BUFFER_TAIL_META(b) (((GstBufferImpl *)(b))->tail_item)
typedef struct
{
GstBuffer buffer;
gsize slice_size;
/* the memory blocks */
guint len;
GstMemory *mem[GST_BUFFER_MEM_MAX];
/* memory of the buffer when allocated from 1 chunk */
GstMemory *bufmem;
/* FIXME, make metadata allocation more efficient by using part of the
* GstBufferImpl */
GstMetaItem *item;
GstMetaItem *tail_item;
} GstBufferImpl;
static gint64 meta_seq; /* 0 *//* ATOMIC */
/* TODO: use GLib's once https://gitlab.gnome.org/GNOME/glib/issues/1076 lands */
#if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8)
static inline gint64
gst_atomic_int64_inc (volatile gint64 * atomic)
{
return __sync_fetch_and_add (atomic, 1);
}
#elif defined (G_PLATFORM_WIN32)
#include <windows.h>
static inline gint64
gst_atomic_int64_inc (volatile gint64 * atomic)
{
return InterlockedExchangeAdd64 (atomic, 1);
}
#else
#define STR_TOKEN(s) #s
#define STR(s) STR_TOKEN(s)
#pragma message "No 64-bit atomic int defined for this " STR(TARGET_CPU) " platform/toolchain!"
#define NO_64BIT_ATOMIC_INT_FOR_PLATFORM
G_LOCK_DEFINE_STATIC (meta_seq);
static inline gint64
gst_atomic_int64_inc (volatile gint64 * atomic)
{
gint64 ret;
G_LOCK (meta_seq);
ret = (*atomic)++;
G_UNLOCK (meta_seq);
return ret;
}
#endif
static gboolean
_is_span (GstMemory ** mem, gsize len, gsize * poffset, GstMemory ** parent)
{
GstMemory *mcur, *mprv;
gboolean have_offset = FALSE;
gsize i;
mcur = mprv = NULL;
for (i = 0; i < len; i++) {
if (mcur)
mprv = mcur;
mcur = mem[i];
if (mprv && mcur) {
gsize poffs;
/* check if memory is contiguous */
if (!gst_memory_is_span (mprv, mcur, &poffs))
return FALSE;
if (!have_offset) {
if (poffset)
*poffset = poffs;
if (parent)
*parent = mprv->parent;
have_offset = TRUE;
}
}
}
return have_offset;
}
static GstMemory *
_actual_merged_memory (GstBuffer * buffer, guint idx, guint length)
{
GstMemory **mem, *result = NULL;
GstMemory *parent = NULL;
gsize size, poffset = 0;
mem = GST_BUFFER_MEM_ARRAY (buffer);
size = gst_buffer_get_sizes_range (buffer, idx, length, NULL, NULL);
if (G_UNLIKELY (_is_span (mem + idx, length, &poffset, &parent))) {
if (!GST_MEMORY_IS_NO_SHARE (parent))
result = gst_memory_share (parent, poffset, size);
if (!result) {
GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy for merge %p", parent);
result = gst_memory_copy (parent, poffset, size);
}
} else {
gsize i, tocopy, left;
GstMapInfo sinfo, dinfo;
guint8 *ptr;
result = gst_allocator_alloc (NULL, size, NULL);
if (result == NULL || !gst_memory_map (result, &dinfo, GST_MAP_WRITE)) {
GST_CAT_ERROR (GST_CAT_BUFFER, "Failed to map memory writable");
if (result)
gst_memory_unref (result);
return NULL;
}
ptr = dinfo.data;
left = size;
for (i = idx; i < (idx + length) && left > 0; i++) {
if (!gst_memory_map (mem[i], &sinfo, GST_MAP_READ)) {
GST_CAT_ERROR (GST_CAT_BUFFER,
"buffer %p, idx %u, length %u failed to map readable", buffer,
idx, length);
gst_memory_unmap (result, &dinfo);
gst_memory_unref (result);
return NULL;
}
tocopy = MIN (sinfo.size, left);
GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
"memcpy %" G_GSIZE_FORMAT " bytes for merge %p from memory %p",
tocopy, result, mem[i]);
memcpy (ptr, (guint8 *) sinfo.data, tocopy);
left -= tocopy;
ptr += tocopy;
gst_memory_unmap (mem[i], &sinfo);
}
gst_memory_unmap (result, &dinfo);
}
return result;
}
static inline GstMemory *
_get_merged_memory (GstBuffer * buffer, guint idx, guint length)
{
GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %u", buffer, idx,
length);
if (G_UNLIKELY (length == 0))
return NULL;
if (G_LIKELY (length == 1))
return gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
return _actual_merged_memory (buffer, idx, length);
}
static void
_replace_memory (GstBuffer * buffer, guint len, guint idx, guint length,
GstMemory * mem)
{
gsize end, i;
end = idx + length;
GST_CAT_LOG (GST_CAT_BUFFER,
"buffer %p replace %u-%" G_GSIZE_FORMAT " with memory %p", buffer, idx,
end, mem);
/* unref old memory */
for (i = idx; i < end; i++) {
GstMemory *old = GST_BUFFER_MEM_PTR (buffer, i);
gst_memory_unlock (old, GST_LOCK_FLAG_EXCLUSIVE);
gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (old),
GST_MINI_OBJECT_CAST (buffer));
gst_memory_unref (old);
}
if (mem != NULL) {
/* replace with single memory */
gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (mem),
GST_MINI_OBJECT_CAST (buffer));
gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
GST_BUFFER_MEM_PTR (buffer, idx) = mem;
idx++;
length--;
}
if (end < len) {
memmove (&GST_BUFFER_MEM_PTR (buffer, idx),
&GST_BUFFER_MEM_PTR (buffer, end), (len - end) * sizeof (gpointer));
}
GST_BUFFER_MEM_LEN (buffer) = len - length;
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
}
/**
* gst_buffer_get_flags:
* @buffer: a #GstBuffer
*
* Gets the #GstBufferFlags flags set on this buffer.
*
* Returns: the flags set on this buffer.
*
* Since: 1.10
*/
GstBufferFlags
gst_buffer_get_flags (GstBuffer * buffer)
{
return (GstBufferFlags) GST_BUFFER_FLAGS (buffer);
}
/**
* gst_buffer_has_flags:
* @buffer: a #GstBuffer
* @flags: the #GstBufferFlags flag to check.
*
* Gives the status of a specific flag on a buffer.
*
* Returns: %TRUE if all flags in @flags are found on @buffer.
*
* Since: 1.10
*/
gboolean
gst_buffer_has_flags (GstBuffer * buffer, GstBufferFlags flags)
{
return GST_BUFFER_FLAG_IS_SET (buffer, flags);
}
/**
* gst_buffer_set_flags:
* @buffer: a #GstBuffer
* @flags: the #GstBufferFlags to set.
*
* Sets one or more buffer flags on a buffer.
*
* Returns: %TRUE if @flags were successfully set on buffer.
*
* Since: 1.10
*/
gboolean
gst_buffer_set_flags (GstBuffer * buffer, GstBufferFlags flags)
{
GST_BUFFER_FLAG_SET (buffer, flags);
return TRUE;
}
/**
* gst_buffer_unset_flags:
* @buffer: a #GstBuffer
* @flags: the #GstBufferFlags to clear
*
* Clears one or more buffer flags.
*
* Returns: true if @flags is successfully cleared from buffer.
*
* Since: 1.10
*/
gboolean
gst_buffer_unset_flags (GstBuffer * buffer, GstBufferFlags flags)
{
GST_BUFFER_FLAG_UNSET (buffer, flags);
return TRUE;
}
/* transfer full for return and transfer none for @mem */
static inline GstMemory *
_memory_get_exclusive_reference (GstMemory * mem)
{
GstMemory *ret = NULL;
if (gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE)) {
ret = gst_memory_ref (mem);
} else {
/* we cannot take another exclusive lock as the memory is already
* locked WRITE + EXCLUSIVE according to part-miniobject.txt */
ret = gst_memory_copy (mem, 0, -1);
if (ret) {
if (!gst_memory_lock (ret, GST_LOCK_FLAG_EXCLUSIVE)) {
gst_memory_unref (ret);
ret = NULL;
}
}
}
if (!ret)
GST_CAT_WARNING (GST_CAT_BUFFER, "Failed to acquire an exclusive lock for "
"memory %p", mem);
return ret;
}
static inline void
_memory_add (GstBuffer * buffer, gint idx, GstMemory * mem)
{
guint i, len = GST_BUFFER_MEM_LEN (buffer);
GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %d, mem %p", buffer, idx, mem);
if (G_UNLIKELY (len >= GST_BUFFER_MEM_MAX)) {
/* too many buffer, span them. */
/* FIXME, there is room for improvement here: We could only try to merge
* 2 buffers to make some room. If we can't efficiently merge 2 buffers we
* could try to only merge the two smallest buffers to avoid memcpy, etc. */
GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "memory array overflow in buffer %p",
buffer);
_replace_memory (buffer, len, 0, len, _get_merged_memory (buffer, 0, len));
/* we now have 1 single spanned buffer */
len = 1;
}
if (idx == -1)
idx = len;
for (i = len; i > idx; i--) {
/* move buffers to insert, FIXME, we need to insert first and then merge */
GST_BUFFER_MEM_PTR (buffer, i) = GST_BUFFER_MEM_PTR (buffer, i - 1);
}
/* and insert the new buffer */
GST_BUFFER_MEM_PTR (buffer, idx) = mem;
GST_BUFFER_MEM_LEN (buffer) = len + 1;
gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (mem),
GST_MINI_OBJECT_CAST (buffer));
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
}
GST_DEFINE_MINI_OBJECT_TYPE (GstBuffer, gst_buffer);
void
_priv_gst_buffer_initialize (void)
{
_gst_buffer_type = gst_buffer_get_type ();
#ifdef NO_64BIT_ATOMIC_INT_FOR_PLATFORM
GST_CAT_WARNING (GST_CAT_PERFORMANCE,
"No 64-bit atomic int defined for this platform/toolchain!");
#endif
}
/**
* gst_buffer_get_max_memory:
*
* Gets the maximum amount of memory blocks that a buffer can hold. This is a
* compile time constant that can be queried with the function.
*
* When more memory blocks are added, existing memory blocks will be merged
* together to make room for the new block.
*
* Returns: the maximum amount of memory blocks that a buffer can hold.
*
* Since: 1.2
*/
guint
gst_buffer_get_max_memory (void)
{
return GST_BUFFER_MEM_MAX;
}
/**
* gst_buffer_copy_into:
* @dest: a destination #GstBuffer
* @src: a source #GstBuffer
* @flags: flags indicating what metadata fields should be copied.
* @offset: offset to copy from
* @size: total size to copy. If -1, all data is copied.
*
* Copies the information from @src into @dest.
*
* If @dest already contains memory and @flags contains GST_BUFFER_COPY_MEMORY,
* the memory from @src will be appended to @dest.
*
* @flags indicate which fields will be copied.
*
* Returns: %TRUE if the copying succeeded, %FALSE otherwise.
*/
gboolean
gst_buffer_copy_into (GstBuffer * dest, GstBuffer * src,
GstBufferCopyFlags flags, gsize offset, gsize size)
{
GstMetaItem *walk;
gsize bufsize;
gboolean region = FALSE;
g_return_val_if_fail (dest != NULL, FALSE);
g_return_val_if_fail (src != NULL, FALSE);
/* nothing to copy if the buffers are the same */
if (G_UNLIKELY (dest == src))
return TRUE;
g_return_val_if_fail (gst_buffer_is_writable (dest), FALSE);
bufsize = gst_buffer_get_size (src);
g_return_val_if_fail (bufsize >= offset, FALSE);
if (offset > 0)
region = TRUE;
if (size == -1)
size = bufsize - offset;
if (size < bufsize)
region = TRUE;
g_return_val_if_fail (bufsize >= offset + size, FALSE);
GST_CAT_LOG (GST_CAT_BUFFER, "copy %p to %p, offset %" G_GSIZE_FORMAT
"-%" G_GSIZE_FORMAT "/%" G_GSIZE_FORMAT, src, dest, offset, size,
bufsize);
if (flags & GST_BUFFER_COPY_FLAGS) {
/* copy flags */
guint flags_mask = ~GST_BUFFER_FLAG_TAG_MEMORY;
GST_MINI_OBJECT_FLAGS (dest) =
(GST_MINI_OBJECT_FLAGS (src) & flags_mask) |
(GST_MINI_OBJECT_FLAGS (dest) & ~flags_mask);
}
if (flags & GST_BUFFER_COPY_TIMESTAMPS) {
if (offset == 0) {
GST_BUFFER_PTS (dest) = GST_BUFFER_PTS (src);
GST_BUFFER_DTS (dest) = GST_BUFFER_DTS (src);
GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET (src);
if (size == bufsize) {
GST_BUFFER_DURATION (dest) = GST_BUFFER_DURATION (src);
GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_END (src);
}
} else {
GST_BUFFER_PTS (dest) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DTS (dest) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DURATION (dest) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (dest) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_OFFSET_END (dest) = GST_BUFFER_OFFSET_NONE;
}
}
if (flags & GST_BUFFER_COPY_MEMORY) {
gsize skip, left, len, dest_len, i, bsize;
gboolean deep;
deep = flags & GST_BUFFER_COPY_DEEP;
len = GST_BUFFER_MEM_LEN (src);
dest_len = GST_BUFFER_MEM_LEN (dest);
left = size;
skip = offset;
/* copy and make regions of the memory */
for (i = 0; i < len && left > 0; i++) {
GstMemory *mem = GST_BUFFER_MEM_PTR (src, i);
bsize = mem->size;
if (bsize <= skip) {
/* don't copy buffer */
skip -= bsize;
} else {
GstMemory *newmem = NULL;
gsize tocopy;
tocopy = MIN (bsize - skip, left);
if (tocopy < bsize && !deep && !GST_MEMORY_IS_NO_SHARE (mem)) {
/* we need to clip something */
newmem = gst_memory_share (mem, skip, tocopy);
if (newmem) {
gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
skip = 0;
}
}
if (deep || GST_MEMORY_IS_NO_SHARE (mem) || (!newmem && tocopy < bsize)) {
/* deep copy or we're not allowed to share this memory
* between buffers, always copy then */
newmem = gst_memory_copy (mem, skip, tocopy);
if (newmem) {
gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
skip = 0;
}
} else if (!newmem) {
newmem = _memory_get_exclusive_reference (mem);
}
if (!newmem) {
gst_buffer_remove_memory_range (dest, dest_len, -1);
return FALSE;
}
_memory_add (dest, -1, newmem);
left -= tocopy;
}
}
if (flags & GST_BUFFER_COPY_MERGE) {
GstMemory *mem;
len = GST_BUFFER_MEM_LEN (dest);
mem = _get_merged_memory (dest, 0, len);
if (!mem) {
gst_buffer_remove_memory_range (dest, dest_len, -1);
return FALSE;
}
_replace_memory (dest, len, 0, len, mem);
}
}
if (flags & GST_BUFFER_COPY_META) {
/* NOTE: GstGLSyncMeta copying relies on the meta
* being copied now, after the buffer data,
* so this has to happen last */
for (walk = GST_BUFFER_META (src); walk; walk = walk->next) {
GstMeta *meta = &walk->meta;
const GstMetaInfo *info = meta->info;
/* Don't copy memory metas if we only copied part of the buffer, didn't
* copy memories or merged memories. In all these cases the memory
* structure has changed and the memory meta becomes meaningless.
*/
if ((region || !(flags & GST_BUFFER_COPY_MEMORY)
|| (flags & GST_BUFFER_COPY_MERGE))
&& gst_meta_api_type_has_tag (info->api, _gst_meta_tag_memory)) {
GST_CAT_DEBUG (GST_CAT_BUFFER,
"don't copy memory meta %p of API type %s", meta,
g_type_name (info->api));
} else if (info->transform_func) {
GstMetaTransformCopy copy_data;
copy_data.region = region;
copy_data.offset = offset;
copy_data.size = size;
if (!info->transform_func (dest, meta, src,
_gst_meta_transform_copy, &copy_data)) {
GST_CAT_ERROR (GST_CAT_BUFFER,
"failed to copy meta %p of API type %s", meta,
g_type_name (info->api));
}
}
}
}
return TRUE;
}
static GstBuffer *
gst_buffer_copy_with_flags (const GstBuffer * buffer, GstBufferCopyFlags flags)
{
GstBuffer *copy;
g_return_val_if_fail (buffer != NULL, NULL);
/* create a fresh new buffer */
copy = gst_buffer_new ();
/* copy what the 'flags' want from our parent */
/* FIXME why we can't pass const to gst_buffer_copy_into() ? */
if (!gst_buffer_copy_into (copy, (GstBuffer *) buffer, flags, 0, -1))
gst_buffer_replace (&copy, NULL);
if (copy)
GST_BUFFER_FLAG_UNSET (copy, GST_BUFFER_FLAG_TAG_MEMORY);
return copy;
}
static GstBuffer *
_gst_buffer_copy (const GstBuffer * buffer)
{
return gst_buffer_copy_with_flags (buffer, GST_BUFFER_COPY_ALL);
}
/**
* gst_buffer_copy_deep:
* @buf: a #GstBuffer.
*
* Creates a copy of the given buffer. This will make a newly allocated
* copy of the data the source buffer contains.
*
* Returns: (transfer full): a new copy of @buf.
*
* Since: 1.6
*/
GstBuffer *
gst_buffer_copy_deep (const GstBuffer * buffer)
{
return gst_buffer_copy_with_flags (buffer,
GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP);
}
/* the default dispose function revives the buffer and returns it to the
* pool when there is a pool */
static gboolean
_gst_buffer_dispose (GstBuffer * buffer)
{
GstBufferPool *pool;
/* no pool, do free */
if ((pool = buffer->pool) == NULL)
return TRUE;
/* keep the buffer alive */
gst_buffer_ref (buffer);
/* return the buffer to the pool */
GST_CAT_LOG (GST_CAT_BUFFER, "release %p to pool %p", buffer, pool);
gst_buffer_pool_release_buffer (pool, buffer);
return FALSE;
}
static void
_gst_buffer_free (GstBuffer * buffer)
{
GstMetaItem *walk, *next;
guint i, len;
gsize msize;
g_return_if_fail (buffer != NULL);
GST_CAT_LOG (GST_CAT_BUFFER, "finalize %p", buffer);
/* free metadata */
for (walk = GST_BUFFER_META (buffer); walk; walk = next) {
GstMeta *meta = &walk->meta;
const GstMetaInfo *info = meta->info;
/* call free_func if any */
if (info->free_func)
info->free_func (meta, buffer);
next = walk->next;
/* and free the slice */
g_slice_free1 (ITEM_SIZE (info), walk);
}
/* get the size, when unreffing the memory, we could also unref the buffer
* itself */
msize = GST_BUFFER_SLICE_SIZE (buffer);
/* free our memory */
len = GST_BUFFER_MEM_LEN (buffer);
for (i = 0; i < len; i++) {
gst_memory_unlock (GST_BUFFER_MEM_PTR (buffer, i), GST_LOCK_FLAG_EXCLUSIVE);
gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (GST_BUFFER_MEM_PTR
(buffer, i)), GST_MINI_OBJECT_CAST (buffer));
gst_memory_unref (GST_BUFFER_MEM_PTR (buffer, i));
}
/* we set msize to 0 when the buffer is part of the memory block */
if (msize) {
#ifdef USE_POISONING
memset (buffer, 0xff, msize);
#endif
g_slice_free1 (msize, buffer);
} else {
gst_memory_unref (GST_BUFFER_BUFMEM (buffer));
}
}
static void
gst_buffer_init (GstBufferImpl * buffer, gsize size)
{
gst_mini_object_init (GST_MINI_OBJECT_CAST (buffer), 0, _gst_buffer_type,
(GstMiniObjectCopyFunction) _gst_buffer_copy,
(GstMiniObjectDisposeFunction) _gst_buffer_dispose,
(GstMiniObjectFreeFunction) _gst_buffer_free);
GST_BUFFER_SLICE_SIZE (buffer) = size;
GST_BUFFER (buffer)->pool = NULL;
GST_BUFFER_PTS (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (buffer) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_OFFSET_END (buffer) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_MEM_LEN (buffer) = 0;
GST_BUFFER_META (buffer) = NULL;
}
/**
* gst_buffer_new:
*
* Creates a newly allocated buffer without any data.
*
* Returns: (transfer full): the new #GstBuffer.
*/
GstBuffer *
gst_buffer_new (void)
{
GstBufferImpl *newbuf;
newbuf = g_slice_new (GstBufferImpl);
GST_CAT_LOG (GST_CAT_BUFFER, "new %p", newbuf);
gst_buffer_init (newbuf, sizeof (GstBufferImpl));
return GST_BUFFER_CAST (newbuf);
}
/**
* gst_buffer_new_allocate:
* @allocator: (transfer none) (allow-none): the #GstAllocator to use, or %NULL to use the
* default allocator
* @size: the size in bytes of the new buffer's data.
* @params: (transfer none) (allow-none): optional parameters
*
* Tries to create a newly allocated buffer with data of the given size and
* extra parameters from @allocator. If the requested amount of memory can't be
* allocated, %NULL will be returned. The allocated buffer memory is not cleared.
*
* When @allocator is %NULL, the default memory allocator will be used.
*
* Note that when @size == 0, the buffer will not have memory associated with it.
*
* Returns: (transfer full) (nullable): a new #GstBuffer
*/
GstBuffer *
gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
GstAllocationParams * params)
{
GstBuffer *newbuf;
GstMemory *mem;
#if 0
guint8 *data;
gsize asize;
#endif
#if 1
if (size > 0) {
mem = gst_allocator_alloc (allocator, size, params);
if (G_UNLIKELY (mem == NULL))
goto no_memory;
} else {
mem = NULL;
}
newbuf = gst_buffer_new ();
if (mem != NULL) {
gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
_memory_add (newbuf, -1, mem);
}
GST_CAT_LOG (GST_CAT_BUFFER,
"new buffer %p of size %" G_GSIZE_FORMAT " from allocator %p", newbuf,
size, allocator);
#endif
#if 0
asize = sizeof (GstBufferImpl) + size;
data = g_slice_alloc (asize);
if (G_UNLIKELY (data == NULL))
goto no_memory;
newbuf = GST_BUFFER_CAST (data);
gst_buffer_init ((GstBufferImpl *) data, asize);
if (size > 0) {
mem = gst_memory_new_wrapped (0, data + sizeof (GstBufferImpl), NULL,
size, 0, size);
_memory_add (newbuf, -1, mem, TRUE);
}
#endif
#if 0
/* allocate memory and buffer, it might be interesting to do this but there
* are many complications. We need to keep the memory mapped to access the
* buffer fields and the memory for the buffer might be just very slow. We
* also need to do some more magic to get the alignment right. */
asize = sizeof (GstBufferImpl) + size;
mem = gst_allocator_alloc (allocator, asize, align);
if (G_UNLIKELY (mem == NULL))
goto no_memory;
/* map the data part and init the buffer in it, set the buffer size to 0 so
* that a finalize won't free the buffer */
data = gst_memory_map (mem, &asize, NULL, GST_MAP_WRITE);
gst_buffer_init ((GstBufferImpl *) data, 0);
gst_memory_unmap (mem);
/* strip off the buffer */
gst_memory_resize (mem, sizeof (GstBufferImpl), size);
newbuf = GST_BUFFER_CAST (data);
GST_BUFFER_BUFMEM (newbuf) = mem;
if (size > 0)
_memory_add (newbuf, -1, gst_memory_ref (mem), TRUE);
#endif
GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
return newbuf;
/* ERRORS */
no_memory:
{
GST_CAT_WARNING (GST_CAT_BUFFER,
"failed to allocate %" G_GSIZE_FORMAT " bytes", size);
return NULL;
}
}
/**
* gst_buffer_new_wrapped_full:
* @flags: #GstMemoryFlags
* @data: (array length=size) (element-type guint8) (transfer none): data to wrap
* @maxsize: allocated size of @data
* @offset: offset in @data
* @size: size of valid data
* @user_data: (allow-none): user_data
* @notify: (allow-none) (scope async) (closure user_data): called with @user_data when the memory is freed
*
* Allocates a new buffer that wraps the given memory. @data must point to
* @maxsize of memory, the wrapped buffer will have the region from @offset and
* @size visible.
*
* When the buffer is destroyed, @notify will be called with @user_data.
*
* The prefix/padding must be filled with 0 if @flags contains
* #GST_MEMORY_FLAG_ZERO_PREFIXED and #GST_MEMORY_FLAG_ZERO_PADDED respectively.
*
* Returns: (transfer full): a new #GstBuffer
*/
GstBuffer *
gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data,
gsize maxsize, gsize offset, gsize size, gpointer user_data,
GDestroyNotify notify)
{
GstMemory *mem;
GstBuffer *newbuf;
newbuf = gst_buffer_new ();
mem =
gst_memory_new_wrapped (flags, data, maxsize, offset, size, user_data,
notify);
gst_memory_lock (mem, GST_LOCK_FLAG_EXCLUSIVE);
_memory_add (newbuf, -1, mem);
GST_BUFFER_FLAG_UNSET (newbuf, GST_BUFFER_FLAG_TAG_MEMORY);
return newbuf;
}
/**
* gst_buffer_new_wrapped:
* @data: (array length=size) (element-type guint8) (transfer full): data to wrap
* @size: allocated size of @data
*
* Creates a new buffer that wraps the given @data. The memory will be freed
* with g_free() and will be marked writable.
*
* Returns: (transfer full): a new #GstBuffer
*/
GstBuffer *
gst_buffer_new_wrapped (gpointer data, gsize size)
{
return gst_buffer_new_wrapped_full (0, data, size, 0, size, data, g_free);
}
/**
* gst_buffer_new_wrapped_bytes:
* @bytes: (transfer none): a #GBytes to wrap
*
* Creates a new #GstBuffer that wraps the given @bytes. The data inside
* @bytes cannot be %NULL and the resulting buffer will be marked as read only.
*
* Returns: (transfer full): a new #GstBuffer wrapping @bytes
*
* Since: 1.16
*/
GstBuffer *
gst_buffer_new_wrapped_bytes (GBytes * bytes)
{
guint8 *bytes_data;
gsize size;
g_return_val_if_fail (bytes != NULL, NULL);
bytes_data = (guint8 *) g_bytes_get_data (bytes, &size);
g_return_val_if_fail (bytes_data != NULL, NULL);
return gst_buffer_new_wrapped_full (GST_MEMORY_FLAG_READONLY, bytes_data,
size, 0, size, g_bytes_ref (bytes), (GDestroyNotify) g_bytes_unref);
}
/**
* gst_buffer_n_memory:
* @buffer: a #GstBuffer.
*
* Gets the amount of memory blocks that this buffer has. This amount is never
* larger than what gst_buffer_get_max_memory() returns.
*
* Returns: the number of memory blocks this buffer is made of.
*/
guint
gst_buffer_n_memory (GstBuffer * buffer)
{
g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
return GST_BUFFER_MEM_LEN (buffer);
}
/**
* gst_buffer_prepend_memory:
* @buffer: a #GstBuffer.
* @mem: (transfer full): a #GstMemory.
*
* Prepends the memory block @mem to @buffer. This function takes
* ownership of @mem and thus doesn't increase its refcount.
*
* This function is identical to gst_buffer_insert_memory() with an index of 0.
* See gst_buffer_insert_memory() for more details.
*/
void
gst_buffer_prepend_memory (GstBuffer * buffer, GstMemory * mem)
{
gst_buffer_insert_memory (buffer, 0, mem);
}
/**
* gst_buffer_append_memory:
* @buffer: a #GstBuffer.
* @mem: (transfer full): a #GstMemory.
*
* Appends the memory block @mem to @buffer. This function takes
* ownership of @mem and thus doesn't increase its refcount.
*
* This function is identical to gst_buffer_insert_memory() with an index of -1.
* See gst_buffer_insert_memory() for more details.
*/
void
gst_buffer_append_memory (GstBuffer * buffer, GstMemory * mem)
{
gst_buffer_insert_memory (buffer, -1, mem);
}
/**
* gst_buffer_insert_memory:
* @buffer: a #GstBuffer.
* @idx: the index to add the memory at, or -1 to append it to the end
* @mem: (transfer full): a #GstMemory.
*
* Inserts the memory block @mem into @buffer at @idx. This function takes ownership
* of @mem and thus doesn't increase its refcount.
*
* Only gst_buffer_get_max_memory() can be added to a buffer. If more memory is
* added, existing memory blocks will automatically be merged to make room for
* the new memory.
*/
void
gst_buffer_insert_memory (GstBuffer * buffer, gint idx, GstMemory * mem)
{
GstMemory *tmp;
g_return_if_fail (GST_IS_BUFFER (buffer));
g_return_if_fail (gst_buffer_is_writable (buffer));
g_return_if_fail (mem != NULL);
g_return_if_fail (idx == -1 ||
(idx >= 0 && idx <= GST_BUFFER_MEM_LEN (buffer)));
tmp = _memory_get_exclusive_reference (mem);
g_return_if_fail (tmp != NULL);
gst_memory_unref (mem);
_memory_add (buffer, idx, tmp);
}
static GstMemory *
_get_mapped (GstBuffer * buffer, guint idx, GstMapInfo * info,
GstMapFlags flags)
{
GstMemory *mem, *mapped;
mem = gst_memory_ref (GST_BUFFER_MEM_PTR (buffer, idx));
mapped = gst_memory_make_mapped (mem, info, flags);
if (mapped != mem) {
/* memory changed, lock new memory */
gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (mapped),
GST_MINI_OBJECT_CAST (buffer));
gst_memory_lock (mapped, GST_LOCK_FLAG_EXCLUSIVE);
GST_BUFFER_MEM_PTR (buffer, idx) = mapped;
/* unlock old memory */
gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (mem),
GST_MINI_OBJECT_CAST (buffer));
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
}
gst_memory_unref (mem);
return mapped;
}
/**
* gst_buffer_peek_memory:
* @buffer: a #GstBuffer.
* @idx: an index
*
* Gets the memory block at @idx in @buffer. The memory block stays valid until
* the memory block in @buffer is removed, replaced or merged, typically with
* any call that modifies the memory in @buffer.
*
* Returns: (transfer none) (nullable): the #GstMemory at @idx.
*/
GstMemory *
gst_buffer_peek_memory (GstBuffer * buffer, guint idx)
{
g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
g_return_val_if_fail (idx < GST_BUFFER_MEM_LEN (buffer), NULL);
return GST_BUFFER_MEM_PTR (buffer, idx);
}
/**
* gst_buffer_get_memory:
* @buffer: a #GstBuffer.
* @idx: an index
*
* Gets the memory block at index @idx in @buffer.
*
* Returns: (transfer full) (nullable): a #GstMemory that contains the data of the
* memory block at @idx.
*/
GstMemory *
gst_buffer_get_memory (GstBuffer * buffer, guint idx)
{
return gst_buffer_get_memory_range (buffer, idx, 1);
}
/**
* gst_buffer_get_all_memory:
* @buffer: a #GstBuffer.
*
* Gets all the memory blocks in @buffer. The memory blocks will be merged
* into one large #GstMemory.
*
* Returns: (transfer full) (nullable): a #GstMemory that contains the merged memory.
*/
GstMemory *
gst_buffer_get_all_memory (GstBuffer * buffer)
{
return gst_buffer_get_memory_range (buffer, 0, -1);
}
/**
* gst_buffer_get_memory_range:
* @buffer: a #GstBuffer.
* @idx: an index
* @length: a length
*
* Gets @length memory blocks in @buffer starting at @idx. The memory blocks will
* be merged into one large #GstMemory.
*
* If @length is -1, all memory starting from @idx is merged.
*
* Returns: (transfer full) (nullable): a #GstMemory that contains the merged data of @length
* blocks starting at @idx.
*/
GstMemory *
gst_buffer_get_memory_range (GstBuffer * buffer, guint idx, gint length)
{
guint len;
GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
len = GST_BUFFER_MEM_LEN (buffer);
g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
(length == -1 && idx < len) || (length > 0 && length + idx <= len), NULL);
if (length == -1)
length = len - idx;
return _get_merged_memory (buffer, idx, length);
}
/**
* gst_buffer_replace_memory:
* @buffer: a #GstBuffer.
* @idx: an index
* @mem: (transfer full): a #GstMemory
*
* Replaces the memory block at index @idx in @buffer with @mem.
*/
void
gst_buffer_replace_memory (GstBuffer * buffer, guint idx, GstMemory * mem)
{
gst_buffer_replace_memory_range (buffer, idx, 1, mem);
}
/**
* gst_buffer_replace_all_memory:
* @buffer: a #GstBuffer.
* @mem: (transfer full): a #GstMemory
*
* Replaces all memory in @buffer with @mem.
*/
void
gst_buffer_replace_all_memory (GstBuffer * buffer, GstMemory * mem)
{
gst_buffer_replace_memory_range (buffer, 0, -1, mem);
}
/**
* gst_buffer_replace_memory_range:
* @buffer: a #GstBuffer.
* @idx: an index
* @length: a length, should not be 0
* @mem: (transfer full): a #GstMemory
*
* Replaces @length memory blocks in @buffer starting at @idx with @mem.
*
* If @length is -1, all memory starting from @idx will be removed and
* replaced with @mem.
*
* @buffer should be writable.
*/
void
gst_buffer_replace_memory_range (GstBuffer * buffer, guint idx, gint length,
GstMemory * mem)
{
guint len;
g_return_if_fail (GST_IS_BUFFER (buffer));
g_return_if_fail (gst_buffer_is_writable (buffer));
GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d, %p", idx, length, mem);
len = GST_BUFFER_MEM_LEN (buffer);
g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
(length == -1 && idx < len) || (length > 0 && length + idx <= len));
if (length == -1)
length = len - idx;
_replace_memory (buffer, len, idx, length, mem);
}
/**
* gst_buffer_remove_memory:
* @buffer: a #GstBuffer.
* @idx: an index
*
* Removes the memory block in @b at index @i.
*/
void
gst_buffer_remove_memory (GstBuffer * buffer, guint idx)
{
gst_buffer_remove_memory_range (buffer, idx, 1);
}
/**
* gst_buffer_remove_all_memory:
* @buffer: a #GstBuffer.
*
* Removes all the memory blocks in @buffer.
*/
void
gst_buffer_remove_all_memory (GstBuffer * buffer)
{
if (GST_BUFFER_MEM_LEN (buffer))
gst_buffer_remove_memory_range (buffer, 0, -1);
}
/**
* gst_buffer_remove_memory_range:
* @buffer: a #GstBuffer.
* @idx: an index
* @length: a length
*
* Removes @length memory blocks in @buffer starting from @idx.
*
* @length can be -1, in which case all memory starting from @idx is removed.
*/
void
gst_buffer_remove_memory_range (GstBuffer * buffer, guint idx, gint length)
{
guint len;
g_return_if_fail (GST_IS_BUFFER (buffer));
g_return_if_fail (gst_buffer_is_writable (buffer));
GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
len = GST_BUFFER_MEM_LEN (buffer);
g_return_if_fail ((len == 0 && idx == 0 && length == -1) ||
(length == -1 && idx < len) || length + idx <= len);
if (length == -1)
length = len - idx;
_replace_memory (buffer, len, idx, length, NULL);
}
/**
* gst_buffer_find_memory:
* @buffer: a #GstBuffer.
* @offset: an offset
* @size: a size
* @idx: (out): pointer to index
* @length: (out): pointer to length
* @skip: (out): pointer to skip
*
* Finds the memory blocks that span @size bytes starting from @offset
* in @buffer.
*
* When this function returns %TRUE, @idx will contain the index of the first
* memory block where the byte for @offset can be found and @length contains the
* number of memory blocks containing the @size remaining bytes. @skip contains
* the number of bytes to skip in the memory block at @idx to get to the byte
* for @offset.
*
* @size can be -1 to get all the memory blocks after @idx.
*
* Returns: %TRUE when @size bytes starting from @offset could be found in
* @buffer and @idx, @length and @skip will be filled.
*/
gboolean
gst_buffer_find_memory (GstBuffer * buffer, gsize offset, gsize size,
guint * idx, guint * length, gsize * skip)
{
guint i, len, found;
g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
g_return_val_if_fail (idx != NULL, FALSE);
g_return_val_if_fail (length != NULL, FALSE);
g_return_val_if_fail (skip != NULL, FALSE);
len = GST_BUFFER_MEM_LEN (buffer);
found = 0;
for (i = 0; i < len; i++) {
GstMemory *mem;
gsize s;
mem = GST_BUFFER_MEM_PTR (buffer, i);
s = mem->size;
if (s <= offset) {
/* block before offset, or empty block, skip */
offset -= s;
} else {
/* block after offset */
if (found == 0) {
/* first block, remember index and offset */
*idx = i;
*skip = offset;
if (size == -1) {
/* return remaining blocks */
*length = len - i;
return TRUE;
}
s -= offset;
offset = 0;
}
/* count the amount of found bytes */
found += s;
if (found >= size) {
/* we have enough bytes */
*length = i - *idx + 1;
return TRUE;
}
}
}
return FALSE;
}
/**
* gst_buffer_is_memory_range_writable:
* @buffer: a #GstBuffer.
* @idx: an index
* @length: a length, should not be 0
*
* Checks if @length memory blocks in @buffer starting from @idx are writable.
*
* @length can be -1 to check all the memory blocks after @idx.
*
* Note that this function does not check if @buffer is writable, use
* gst_buffer_is_writable() to check that if needed.
*
* Returns: %TRUE if the memory range is writable
*
* Since: 1.4
*/
gboolean
gst_buffer_is_memory_range_writable (GstBuffer * buffer, guint idx, gint length)
{
guint i, len;
g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
GST_CAT_DEBUG (GST_CAT_BUFFER, "idx %u, length %d", idx, length);
len = GST_BUFFER_MEM_LEN (buffer);
g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
(length == -1 && idx < len) || (length > 0 && length + idx <= len),
FALSE);
if (length == -1)
len -= idx;
else
len = length;
for (i = 0; i < len; i++) {
if (!gst_memory_is_writable (GST_BUFFER_MEM_PTR (buffer, i + idx)))
return FALSE;
}
return TRUE;
}
/**
* gst_buffer_is_all_memory_writable:
* @buffer: a #GstBuffer.
*
* Checks if all memory blocks in @buffer are writable.
*
* Note that this function does not check if @buffer is writable, use
* gst_buffer_is_writable() to check that if needed.
*
* Returns: %TRUE if all memory blocks in @buffer are writable
*
* Since: 1.4
*/
gboolean
gst_buffer_is_all_memory_writable (GstBuffer * buffer)
{
return gst_buffer_is_memory_range_writable (buffer, 0, -1);
}
/**
* gst_buffer_get_sizes:
* @buffer: a #GstBuffer.
* @offset: (out) (allow-none): a pointer to the offset
* @maxsize: (out) (allow-none): a pointer to the maxsize
*
* Gets the total size of the memory blocks in @buffer.
*
* When not %NULL, @offset will contain the offset of the data in the
* first memory block in @buffer and @maxsize will contain the sum of
* the size and @offset and the amount of extra padding on the last
* memory block. @offset and @maxsize can be used to resize the
* buffer memory blocks with gst_buffer_resize().
*
* Returns: total size of the memory blocks in @buffer.
*/
gsize
gst_buffer_get_sizes (GstBuffer * buffer, gsize * offset, gsize * maxsize)
{
return gst_buffer_get_sizes_range (buffer, 0, -1, offset, maxsize);
}
/**
* gst_buffer_get_size:
* @buffer: a #GstBuffer.
*
* Gets the total size of the memory blocks in @buffer.
*
* Returns: total size of the memory blocks in @buffer.
*/
gsize
gst_buffer_get_size (GstBuffer * buffer)
{
guint i;
gsize size, len;
g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
/* FAST PATH */
len = GST_BUFFER_MEM_LEN (buffer);
for (i = 0, size = 0; i < len; i++)
size += GST_BUFFER_MEM_PTR (buffer, i)->size;
return size;
}
/**
* gst_buffer_get_sizes_range:
* @buffer: a #GstBuffer.
* @idx: an index
* @length: a length
* @offset: (out) (allow-none): a pointer to the offset
* @maxsize: (out) (allow-none): a pointer to the maxsize
*
* Gets the total size of @length memory blocks stating from @idx in @buffer.
*
* When not %NULL, @offset will contain the offset of the data in the
* memory block in @buffer at @idx and @maxsize will contain the sum of the size
* and @offset and the amount of extra padding on the memory block at @idx +
* @length -1.
* @offset and @maxsize can be used to resize the buffer memory blocks with
* gst_buffer_resize_range().
*
* Returns: total size of @length memory blocks starting at @idx in @buffer.
*/
gsize
gst_buffer_get_sizes_range (GstBuffer * buffer, guint idx, gint length,
gsize * offset, gsize * maxsize)
{
guint len;
gsize size;
GstMemory *mem;
g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
len = GST_BUFFER_MEM_LEN (buffer);
g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
(length == -1 && idx < len) || (length + idx <= len), 0);
if (length == -1)
length = len - idx;
if (G_LIKELY (length == 1)) {
/* common case */
mem = GST_BUFFER_MEM_PTR (buffer, idx);
size = gst_memory_get_sizes (mem, offset, maxsize);
} else if (offset == NULL && maxsize == NULL) {
/* FAST PATH ! */
guint i, end;
size = 0;
end = idx + length;
for (i = idx; i < end; i++) {
mem = GST_BUFFER_MEM_PTR (buffer, i);
size += mem->size;
}
} else {
guint i, end;
gsize extra, offs;
end = idx + length;
size = offs = extra = 0;
for (i = idx; i < end; i++) {
gsize s, o, ms;
mem = GST_BUFFER_MEM_PTR (buffer, i);
s = gst_memory_get_sizes (mem, &o, &ms);
if (s) {
if (size == 0)
/* first size, take accumulated data before as the offset */
offs = extra + o;
/* add sizes */
size += s;
/* save the amount of data after this block */
extra = ms - (o + s);
} else {
/* empty block, add as extra */
extra += ms;
}
}
if (offset)
*offset = offs;
if (maxsize)
*maxsize = offs + size + extra;
}
return size;
}
/**
* gst_buffer_resize:
* @buffer: a #GstBuffer.
* @offset: the offset adjustment
* @size: the new size or -1 to just adjust the offset
*
* Sets the offset and total size of the memory blocks in @buffer.
*/
void
gst_buffer_resize (GstBuffer * buffer, gssize offset, gssize size)
{
gst_buffer_resize_range (buffer, 0, -1, offset, size);
}
/**
* gst_buffer_set_size:
* @buffer: a #GstBuffer.
* @size: the new size
*
* Sets the total size of the memory blocks in @buffer.
*/
void
gst_buffer_set_size (GstBuffer * buffer, gssize size)
{
gst_buffer_resize_range (buffer, 0, -1, 0, size);
}
/**
* gst_buffer_resize_range:
* @buffer: a #GstBuffer.
* @idx: an index
* @length: a length
* @offset: the offset adjustment
* @size: the new size or -1 to just adjust the offset
*
* Sets the total size of the @length memory blocks starting at @idx in
* @buffer
*
* Returns: %TRUE if resizing succeeded, %FALSE otherwise.
*/
gboolean
gst_buffer_resize_range (GstBuffer * buffer, guint idx, gint length,
gssize offset, gssize size)
{
guint i, len, end;
gsize bsize, bufsize, bufoffs, bufmax;
g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
g_return_val_if_fail (size >= -1, FALSE);
len = GST_BUFFER_MEM_LEN (buffer);
g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
(length == -1 && idx < len) || (length + idx <= len), FALSE);
if (length == -1)
length = len - idx;
bufsize = gst_buffer_get_sizes_range (buffer, idx, length, &bufoffs, &bufmax);
GST_CAT_LOG (GST_CAT_BUFFER, "trim %p %" G_GSSIZE_FORMAT "-%" G_GSSIZE_FORMAT
" size:%" G_GSIZE_FORMAT " offs:%" G_GSIZE_FORMAT " max:%"
G_GSIZE_FORMAT, buffer, offset, size, bufsize, bufoffs, bufmax);
/* we can't go back further than the current offset or past the end of the
* buffer */
g_return_val_if_fail ((offset < 0 && bufoffs >= -offset) || (offset >= 0
&& bufoffs + offset <= bufmax), FALSE);
if (size == -1) {
g_return_val_if_fail (bufsize >= offset, FALSE);
size = bufsize - offset;
}
g_return_val_if_fail (bufmax >= bufoffs + offset + size, FALSE);
/* no change */
if (offset == 0 && size == bufsize)
return TRUE;
end = idx + length;
/* copy and trim */
for (i = idx; i < end; i++) {
GstMemory *mem;
gsize left, noffs;
mem = GST_BUFFER_MEM_PTR (buffer, i);
bsize = mem->size;
noffs = 0;
/* last buffer always gets resized to the remaining size */
if (i + 1 == end)
left = size;
/* shrink buffers before the offset */
else if ((gssize) bsize <= offset) {
left = 0;
noffs = offset - bsize;
offset = 0;
}
/* clip other buffers */
else
left = MIN (bsize - offset, size);
if (offset != 0 || left != bsize) {
if (gst_memory_is_writable (mem)) {
gst_memory_resize (mem, offset, left);
} else {
GstMemory *newmem = NULL;
if (!GST_MEMORY_IS_NO_SHARE (mem))
newmem = gst_memory_share (mem, offset, left);
if (!newmem)
newmem = gst_memory_copy (mem, offset, left);
if (newmem == NULL)
return FALSE;
gst_mini_object_add_parent (GST_MINI_OBJECT_CAST (newmem),
GST_MINI_OBJECT_CAST (buffer));
gst_memory_lock (newmem, GST_LOCK_FLAG_EXCLUSIVE);
GST_BUFFER_MEM_PTR (buffer, i) = newmem;
gst_memory_unlock (mem, GST_LOCK_FLAG_EXCLUSIVE);
gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (mem),
GST_MINI_OBJECT_CAST (buffer));
gst_memory_unref (mem);
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_TAG_MEMORY);
}
}
offset = noffs;
size -= left;
}
return TRUE;
}
/**
* gst_buffer_map:
* @buffer: a #GstBuffer.
* @info: (out caller-allocates): info about the mapping
* @flags: flags for the mapping
*
* Fills @info with the #GstMapInfo of all merged memory blocks in @buffer.
*
* @flags describe the desired access of the memory. When @flags is
* #GST_MAP_WRITE, @buffer should be writable (as returned from
* gst_buffer_is_writable()).
*
* When @buffer is writable but the memory isn't, a writable copy will
* automatically be created and returned. The readonly copy of the
* buffer memory will then also be replaced with this writable copy.
*
* The memory in @info should be unmapped with gst_buffer_unmap() after
* usage.
*
* Returns: %TRUE if the map succeeded and @info contains valid data.
*/
gboolean
gst_buffer_map (GstBuffer * buffer, GstMapInfo * info, GstMapFlags flags)
{
return gst_buffer_map_range (buffer, 0, -1, info, flags);
}
/**
* gst_buffer_map_range:
* @buffer: a #GstBuffer.
* @idx: an index
* @length: a length
* @info: (out caller-allocates): info about the mapping
* @flags: flags for the mapping
*
* Fills @info with the #GstMapInfo of @length merged memory blocks
* starting at @idx in @buffer. When @length is -1, all memory blocks starting
* from @idx are merged and mapped.
*
* @flags describe the desired access of the memory. When @flags is
* #GST_MAP_WRITE, @buffer should be writable (as returned from
* gst_buffer_is_writable()).
*
* When @buffer is writable but the memory isn't, a writable copy will
* automatically be created and returned. The readonly copy of the buffer memory
* will then also be replaced with this writable copy.
*
* The memory in @info should be unmapped with gst_buffer_unmap() after usage.
*
* Returns: %TRUE if the map succeeded and @info contains valid
* data.
*/
gboolean
gst_buffer_map_range (GstBuffer * buffer, guint idx, gint length,
GstMapInfo * info, GstMapFlags flags)
{
GstMemory *mem, *nmem;
gboolean write, writable;
gsize len;
g_return_val_if_fail (GST_IS_BUFFER (buffer), FALSE);
g_return_val_if_fail (info != NULL, FALSE);
len = GST_BUFFER_MEM_LEN (buffer);
g_return_val_if_fail ((len == 0 && idx == 0 && length == -1) ||
(length == -1 && idx < len) || (length > 0
&& length + idx <= len), FALSE);
GST_CAT_LOG (GST_CAT_BUFFER, "buffer %p, idx %u, length %d, flags %04x",
buffer, idx, length, flags);
write = (flags & GST_MAP_WRITE) != 0;
writable = gst_buffer_is_writable (buffer);
/* check if we can write when asked for write access */
if (G_UNLIKELY (write && !writable))
goto not_writable;
if (length == -1)
length = len - idx;
mem = _get_merged_memory (buffer, idx, length);
if (G_UNLIKELY (mem == NULL))
goto no_memory;
/* now try to map */
nmem = gst_memory_make_mapped (mem, info, flags);
if (G_UNLIKELY (nmem == NULL))
goto cannot_map;
/* if we merged or when the map returned a different memory, we try to replace
* the memory in the buffer */
if (G_UNLIKELY (length > 1 || nmem != mem)) {
/* if the buffer is writable, replace the memory */
if (writable) {
_replace_memory (buffer, len, idx, length, gst_memory_ref (nmem));
} else {
if (len > 1) {
GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
"temporary mapping for memory %p in buffer %p", nmem, buffer);
}
}
}
return TRUE;
/* ERROR */
not_writable:
{
GST_WARNING ("write map requested on non-writable buffer");
g_critical ("write map requested on non-writable buffer");
memset (info, 0, sizeof (GstMapInfo));
return FALSE;
}
no_memory:
{
/* empty buffer, we need to return NULL */
GST_DEBUG ("can't get buffer memory");
memset (info, 0, sizeof (GstMapInfo));
return TRUE;
}
cannot_map:
{
GST_DEBUG ("cannot map memory");
memset (info, 0, sizeof (GstMapInfo));
return FALSE;
}
}
/**
* gst_buffer_unmap:
* @buffer: a #GstBuffer.
* @info: a #GstMapInfo
*
* Releases the memory previously mapped with gst_buffer_map().
*/
void
gst_buffer_unmap (GstBuffer * buffer, GstMapInfo * info)
{
g_return_if_fail (GST_IS_BUFFER (buffer));
g_return_if_fail (info != NULL);
/* we need to check for NULL, it is possible that we tried to map a buffer
* without memory and we should be able to unmap that fine */
if (G_LIKELY (info->memory)) {
gst_memory_unmap (info->memory, info);
gst_memory_unref (info->memory);
}
}
/**
* gst_buffer_fill:
* @buffer: a #GstBuffer.
* @offset: the offset to fill
* @src: (array length=size) (element-type guint8): the source address
* @size: the size to fill
*
* Copies @size bytes from @src to @buffer at @offset.
*
* Returns: The amount of bytes copied. This value can be lower than @size
* when @buffer did not contain enough data.
*/
gsize
gst_buffer_fill (GstBuffer * buffer, gsize offset, gconstpointer src,
gsize size)
{
gsize i, len, left;
const guint8 *ptr = src;
g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
g_return_val_if_fail (src != NULL || size == 0, 0);
GST_CAT_LOG (GST_CAT_BUFFER,
"buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
offset, size);
len = GST_BUFFER_MEM_LEN (buffer);
left = size;
for (i = 0; i < len && left > 0; i++) {
GstMapInfo info;
gsize tocopy;
GstMemory *mem;
mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
if (info.size > offset) {
/* we have enough */
tocopy = MIN (info.size - offset, left);
memcpy ((guint8 *) info.data + offset, ptr, tocopy);
left -= tocopy;
ptr += tocopy;
offset = 0;
} else {
/* offset past buffer, skip */
offset -= info.size;
}
gst_memory_unmap (mem, &info);
}
return size - left;
}
/**
* gst_buffer_extract:
* @buffer: a #GstBuffer.
* @offset: the offset to extract
* @dest: (out caller-allocates) (array length=size) (element-type guint8):
* the destination address
* @size: the size to extract
*
* Copies @size bytes starting from @offset in @buffer to @dest.
*
* Returns: The amount of bytes extracted. This value can be lower than @size
* when @buffer did not contain enough data.
*/
gsize
gst_buffer_extract (GstBuffer * buffer, gsize offset, gpointer dest, gsize size)
{
gsize i, len, left;
guint8 *ptr = dest;
g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
g_return_val_if_fail (dest != NULL, 0);
GST_CAT_LOG (GST_CAT_BUFFER,
"buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
offset, size);
len = GST_BUFFER_MEM_LEN (buffer);
left = size;
for (i = 0; i < len && left > 0; i++) {
GstMapInfo info;
gsize tocopy;
GstMemory *mem;
mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
if (info.size > offset) {
/* we have enough */
tocopy = MIN (info.size - offset, left);
memcpy (ptr, (guint8 *) info.data + offset, tocopy);
left -= tocopy;
ptr += tocopy;
offset = 0;
} else {
/* offset past buffer, skip */
offset -= info.size;
}
gst_memory_unmap (mem, &info);
}
return size - left;
}
/**
* gst_buffer_memcmp:
* @buffer: a #GstBuffer.
* @offset: the offset in @buffer
* @mem: (array length=size) (element-type guint8): the memory to compare
* @size: the size to compare
*
* Compares @size bytes starting from @offset in @buffer with the memory in @mem.
*
* Returns: 0 if the memory is equal.
*/
gint
gst_buffer_memcmp (GstBuffer * buffer, gsize offset, gconstpointer mem,
gsize size)
{
gsize i, len;
const guint8 *ptr = mem;
gint res = 0;
g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
g_return_val_if_fail (mem != NULL, 0);
GST_CAT_LOG (GST_CAT_BUFFER,
"buffer %p, offset %" G_GSIZE_FORMAT ", size %" G_GSIZE_FORMAT, buffer,
offset, size);
if (G_UNLIKELY (gst_buffer_get_size (buffer) < offset + size))
return -1;
len = GST_BUFFER_MEM_LEN (buffer);
for (i = 0; i < len && size > 0 && res == 0; i++) {
GstMapInfo info;
gsize tocmp;
GstMemory *mem;
mem = _get_mapped (buffer, i, &info, GST_MAP_READ);
if (info.size > offset) {
/* we have enough */
tocmp = MIN (info.size - offset, size);
res = memcmp (ptr, (guint8 *) info.data + offset, tocmp);
size -= tocmp;
ptr += tocmp;
offset = 0;
} else {
/* offset past buffer, skip */
offset -= info.size;
}
gst_memory_unmap (mem, &info);
}
return res;
}
/**
* gst_buffer_memset:
* @buffer: a #GstBuffer.
* @offset: the offset in @buffer
* @val: the value to set
* @size: the size to set
*
* Fills @buf with @size bytes with @val starting from @offset.
*
* Returns: The amount of bytes filled. This value can be lower than @size
* when @buffer did not contain enough data.
*/
gsize
gst_buffer_memset (GstBuffer * buffer, gsize offset, guint8 val, gsize size)
{
gsize i, len, left;
g_return_val_if_fail (GST_IS_BUFFER (buffer), 0);
g_return_val_if_fail (gst_buffer_is_writable (buffer), 0);
GST_CAT_LOG (GST_CAT_BUFFER,
"buffer %p, offset %" G_GSIZE_FORMAT ", val %02x, size %" G_GSIZE_FORMAT,
buffer, offset, val, size);
len = GST_BUFFER_MEM_LEN (buffer);
left = size;
for (i = 0; i < len && left > 0; i++) {
GstMapInfo info;
gsize toset;
GstMemory *mem;
mem = _get_mapped (buffer, i, &info, GST_MAP_WRITE);
if (info.size > offset) {
/* we have enough */
toset = MIN (info.size - offset, left);
memset ((guint8 *) info.data + offset, val, toset);
left -= toset;
offset = 0;
} else {
/* offset past buffer, skip */
offset -= info.size;
}
gst_memory_unmap (mem, &info);
}
return size - left;
}
/**
* gst_buffer_copy_region:
* @parent: a #GstBuffer.
* @flags: the #GstBufferCopyFlags
* @offset: the offset into parent #GstBuffer at which the new sub-buffer
* begins.
* @size: the size of the new #GstBuffer sub-buffer, in bytes. If -1, all
* data is copied.
*
* Creates a sub-buffer from @parent at @offset and @size.
* This sub-buffer uses the actual memory space of the parent buffer.
* This function will copy the offset and timestamp fields when the
* offset is 0. If not, they will be set to #GST_CLOCK_TIME_NONE and
* #GST_BUFFER_OFFSET_NONE.
* If @offset equals 0 and @size equals the total size of @buffer, the
* duration and offset end fields are also copied. If not they will be set
* to #GST_CLOCK_TIME_NONE and #GST_BUFFER_OFFSET_NONE.
*
* Returns: (transfer full): the new #GstBuffer or %NULL if the arguments were
* invalid.
*/
GstBuffer *
gst_buffer_copy_region (GstBuffer * buffer, GstBufferCopyFlags flags,
gsize offset, gsize size)
{
GstBuffer *copy;
g_return_val_if_fail (buffer != NULL, NULL);
/* create the new buffer */
copy = gst_buffer_new ();
GST_CAT_LOG (GST_CAT_BUFFER, "new region copy %p of %p %" G_GSIZE_FORMAT
"-%" G_GSIZE_FORMAT, copy, buffer, offset, size);
if (!gst_buffer_copy_into (copy, buffer, flags, offset, size))
gst_buffer_replace (&copy, NULL);
return copy;
}
/**
* gst_buffer_append:
* @buf1: (transfer full): the first source #GstBuffer to append.
* @buf2: (transfer full): the second source #GstBuffer to append.
*
* Appends all the memory from @buf2 to @buf1. The result buffer will contain a
* concatenation of the memory of @buf1 and @buf2.
*
* Returns: (transfer full): the new #GstBuffer that contains the memory
* of the two source buffers.
*/
GstBuffer *
gst_buffer_append (GstBuffer * buf1, GstBuffer * buf2)
{
return gst_buffer_append_region (buf1, buf2, 0, -1);
}
/**
* gst_buffer_append_region:
* @buf1: (transfer full): the first source #GstBuffer to append.
* @buf2: (transfer full): the second source #GstBuffer to append.
* @offset: the offset in @buf2
* @size: the size or -1 of @buf2
*
* Appends @size bytes at @offset from @buf2 to @buf1. The result buffer will
* contain a concatenation of the memory of @buf1 and the requested region of
* @buf2.
*
* Returns: (transfer full): the new #GstBuffer that contains the memory
* of the two source buffers.
*/
GstBuffer *
gst_buffer_append_region (GstBuffer * buf1, GstBuffer * buf2, gssize offset,
gssize size)
{
gsize i, len;
g_return_val_if_fail (GST_IS_BUFFER (buf1), NULL);
g_return_val_if_fail (GST_IS_BUFFER (buf2), NULL);
buf1 = gst_buffer_make_writable (buf1);
buf2 = gst_buffer_make_writable (buf2);
gst_buffer_resize (buf2, offset, size);
len = GST_BUFFER_MEM_LEN (buf2);
for (i = 0; i < len; i++) {
GstMemory *mem;
mem = GST_BUFFER_MEM_PTR (buf2, i);
gst_mini_object_remove_parent (GST_MINI_OBJECT_CAST (mem),
GST_MINI_OBJECT_CAST (buf2));
GST_BUFFER_MEM_PTR (buf2, i) = NULL;
_memory_add (buf1, -1, mem);
}
GST_BUFFER_MEM_LEN (buf2) = 0;
GST_BUFFER_FLAG_SET (buf2, GST_BUFFER_FLAG_TAG_MEMORY);
gst_buffer_unref (buf2);
return buf1;
}
/**
* gst_buffer_get_meta:
* @buffer: a #GstBuffer
* @api: the #GType of an API
*
* Gets the metadata for @api on buffer. When there is no such metadata, %NULL is
* returned. If multiple metadata with the given @api are attached to this
* buffer only the first one is returned. To handle multiple metadata with a
* given API use gst_buffer_iterate_meta() or gst_buffer_foreach_meta() instead
* and check the `meta->info.api` member for the API type.
*
* Returns: (transfer none) (nullable): the metadata for @api on @buffer.
*/
GstMeta *
gst_buffer_get_meta (GstBuffer * buffer, GType api)
{
GstMetaItem *item;
GstMeta *result = NULL;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (api != 0, NULL);
/* find GstMeta of the requested API */
for (item = GST_BUFFER_META (buffer); item; item = item->next) {
GstMeta *meta = &item->meta;
if (meta->info->api == api) {
result = meta;
break;
}
}
return result;
}
/**
* gst_buffer_get_n_meta:
* @buffer: a #GstBuffer
* @api_type: the #GType of an API
*
* Returns: number of metas of type @api_type on @buffer.
*
* Since: 1.14
*/
guint
gst_buffer_get_n_meta (GstBuffer * buffer, GType api_type)
{
gpointer state = NULL;
GstMeta *meta;
guint n = 0;
while ((meta = gst_buffer_iterate_meta_filtered (buffer, &state, api_type)))
++n;
return n;
}
/**
* gst_buffer_add_meta:
* @buffer: a #GstBuffer
* @info: a #GstMetaInfo
* @params: params for @info
*
* Adds metadata for @info to @buffer using the parameters in @params.
*
* Returns: (transfer none) (nullable): the metadata for the api in @info on @buffer.
*/
GstMeta *
gst_buffer_add_meta (GstBuffer * buffer, const GstMetaInfo * info,
gpointer params)
{
GstMetaItem *item;
GstMeta *result = NULL;
gsize size;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (info != NULL, NULL);
g_return_val_if_fail (gst_buffer_is_writable (buffer), NULL);
/* create a new slice */
size = ITEM_SIZE (info);
/* We warn in gst_meta_register() about metas without
* init function but let's play safe here and prevent
* uninitialized memory
*/
if (!info->init_func)
item = g_slice_alloc0 (size);
else
item = g_slice_alloc (size);
result = &item->meta;
result->info = info;
result->flags = GST_META_FLAG_NONE;
GST_CAT_DEBUG (GST_CAT_BUFFER,
"alloc metadata %p (%s) of size %" G_GSIZE_FORMAT, result,
g_type_name (info->type), info->size);
/* call the init_func when needed */
if (info->init_func)
if (!info->init_func (result, params, buffer))
goto init_failed;
item->seq_num = gst_atomic_int64_inc (&meta_seq);
item->next = NULL;
if (!GST_BUFFER_META (buffer)) {
GST_BUFFER_META (buffer) = item;
GST_BUFFER_TAIL_META (buffer) = item;
} else {
GST_BUFFER_TAIL_META (buffer)->next = item;
GST_BUFFER_TAIL_META (buffer) = item;
}
return result;
init_failed:
{
g_slice_free1 (size, item);
return NULL;
}
}
/**
* gst_buffer_remove_meta:
* @buffer: a #GstBuffer
* @meta: a #GstMeta
*
* Removes the metadata for @meta on @buffer.
*
* Returns: %TRUE if the metadata existed and was removed, %FALSE if no such
* metadata was on @buffer.
*/
gboolean
gst_buffer_remove_meta (GstBuffer * buffer, GstMeta * meta)
{
GstMetaItem *walk, *prev;
g_return_val_if_fail (buffer != NULL, FALSE);
g_return_val_if_fail (meta != NULL, FALSE);
g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
g_return_val_if_fail (!GST_META_FLAG_IS_SET (meta, GST_META_FLAG_LOCKED),
FALSE);
/* find the metadata and delete */
prev = GST_BUFFER_META (buffer);
for (walk = prev; walk; walk = walk->next) {
GstMeta *m = &walk->meta;
if (m == meta) {
const GstMetaInfo *info = meta->info;
/* remove from list */
if (GST_BUFFER_TAIL_META (buffer) == walk) {
if (prev != walk)
GST_BUFFER_TAIL_META (buffer) = prev;
else
GST_BUFFER_TAIL_META (buffer) = NULL;
}
if (GST_BUFFER_META (buffer) == walk)
GST_BUFFER_META (buffer) = walk->next;
else
prev->next = walk->next;
/* call free_func if any */
if (info->free_func)
info->free_func (m, buffer);
/* and free the slice */
g_slice_free1 (ITEM_SIZE (info), walk);
break;
}
prev = walk;
}
return walk != NULL;
}
/**
* gst_buffer_iterate_meta: (skip)
* @buffer: a #GstBuffer
* @state: (out caller-allocates): an opaque state pointer
*
* Retrieves the next #GstMeta after @current. If @state points
* to %NULL, the first metadata is returned.
*
* @state will be updated with an opaque state pointer
*
* Returns: (transfer none) (nullable): The next #GstMeta or %NULL
* when there are no more items.
*/
GstMeta *
gst_buffer_iterate_meta (GstBuffer * buffer, gpointer * state)
{
GstMetaItem **meta;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (state != NULL, NULL);
meta = (GstMetaItem **) state;
if (*meta == NULL)
/* state NULL, move to first item */
*meta = GST_BUFFER_META (buffer);
else
/* state !NULL, move to next item in list */
*meta = (*meta)->next;
if (*meta)
return &(*meta)->meta;
else
return NULL;
}
/**
* gst_buffer_iterate_meta_filtered: (skip)
* @buffer: a #GstBuffer
* @state: (out caller-allocates): an opaque state pointer
* @meta_api_type: only return #GstMeta of this type
*
* Retrieves the next #GstMeta of type @meta_api_type after the current one
* according to @state. If @state points to %NULL, the first metadata of
* type @meta_api_type is returned.
*
* @state will be updated with an opaque state pointer
*
* Returns: (transfer none) (nullable): The next #GstMeta of type
* @meta_api_type or %NULL when there are no more items.
*
* Since: 1.12
*/
GstMeta *
gst_buffer_iterate_meta_filtered (GstBuffer * buffer, gpointer * state,
GType meta_api_type)
{
GstMetaItem **meta;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (state != NULL, NULL);
meta = (GstMetaItem **) state;
if (*meta == NULL)
/* state NULL, move to first item */
*meta = GST_BUFFER_META (buffer);
else
/* state !NULL, move to next item in list */
*meta = (*meta)->next;
while (*meta != NULL && (*meta)->meta.info->api != meta_api_type)
*meta = (*meta)->next;
if (*meta)
return &(*meta)->meta;
else
return NULL;
}
/**
* gst_buffer_foreach_meta:
* @buffer: a #GstBuffer
* @func: (scope call): a #GstBufferForeachMetaFunc to call
* @user_data: (closure): user data passed to @func
*
* Calls @func with @user_data for each meta in @buffer.
*
* @func can modify the passed meta pointer or its contents. The return value
* of @func defines if this function returns or if the remaining metadata items
* in the buffer should be skipped.
*
* Returns: %FALSE when @func returned %FALSE for one of the metadata.
*/
gboolean
gst_buffer_foreach_meta (GstBuffer * buffer, GstBufferForeachMetaFunc func,
gpointer user_data)
{
GstMetaItem *walk, *prev, *next;
gboolean res = TRUE;
g_return_val_if_fail (buffer != NULL, FALSE);
g_return_val_if_fail (func != NULL, FALSE);
/* find the metadata and delete */
prev = GST_BUFFER_META (buffer);
for (walk = prev; walk; walk = next) {
GstMeta *m, *new;
m = new = &walk->meta;
next = walk->next;
res = func (buffer, &new, user_data);
if (new == NULL) {
const GstMetaInfo *info = m->info;
GST_CAT_DEBUG (GST_CAT_BUFFER, "remove metadata %p (%s)", m,
g_type_name (info->type));
g_return_val_if_fail (gst_buffer_is_writable (buffer), FALSE);
g_return_val_if_fail (!GST_META_FLAG_IS_SET (m, GST_META_FLAG_LOCKED),
FALSE);
if (GST_BUFFER_TAIL_META (buffer) == walk) {
if (prev != walk)
GST_BUFFER_TAIL_META (buffer) = prev;
else
GST_BUFFER_TAIL_META (buffer) = NULL;
}
/* remove from list */
if (GST_BUFFER_META (buffer) == walk)
prev = GST_BUFFER_META (buffer) = next;
else
prev->next = next;
/* call free_func if any */
if (info->free_func)
info->free_func (m, buffer);
/* and free the slice */
g_slice_free1 (ITEM_SIZE (info), walk);
} else {
prev = walk;
}
if (!res)
break;
}
return res;
}
/**
* gst_buffer_extract_dup:
* @buffer: a #GstBuffer
* @offset: the offset to extract
* @size: the size to extract
* @dest: (array length=dest_size) (element-type guint8) (out): A pointer where
* the destination array will be written. Might be %NULL if the size is 0.
* @dest_size: (out): A location where the size of @dest can be written
*
* Extracts a copy of at most @size bytes the data at @offset into
* newly-allocated memory. @dest must be freed using g_free() when done.
*
* Since: 1.0.10
*/
void
gst_buffer_extract_dup (GstBuffer * buffer, gsize offset, gsize size,
gpointer * dest, gsize * dest_size)
{
gsize real_size, alloc_size;
real_size = gst_buffer_get_size (buffer);
alloc_size = MIN (real_size - offset, size);
if (alloc_size == 0) {
*dest = NULL;
*dest_size = 0;
} else {
*dest = g_malloc (alloc_size);
*dest_size = gst_buffer_extract (buffer, offset, *dest, size);
}
}
GST_DEBUG_CATEGORY_STATIC (gst_parent_buffer_meta_debug);
/**
* gst_buffer_add_parent_buffer_meta:
* @buffer: (transfer none): a #GstBuffer
* @ref: (transfer none): a #GstBuffer to ref
*
* Adds a #GstParentBufferMeta to @buffer that holds a reference on
* @ref until the buffer is freed.
*
* Returns: (transfer none) (nullable): The #GstParentBufferMeta that was added to the buffer
*
* Since: 1.6
*/
GstParentBufferMeta *
gst_buffer_add_parent_buffer_meta (GstBuffer * buffer, GstBuffer * ref)
{
GstParentBufferMeta *meta;
g_return_val_if_fail (GST_IS_BUFFER (ref), NULL);
meta =
(GstParentBufferMeta *) gst_buffer_add_meta (buffer,
GST_PARENT_BUFFER_META_INFO, NULL);
if (!meta)
return NULL;
meta->buffer = gst_buffer_ref (ref);
return meta;
}
static gboolean
_gst_parent_buffer_meta_transform (GstBuffer * dest, GstMeta * meta,
GstBuffer * buffer, GQuark type, gpointer data)
{
GstParentBufferMeta *dmeta, *smeta;
smeta = (GstParentBufferMeta *) meta;
if (GST_META_TRANSFORM_IS_COPY (type)) {
/* copy over the reference to the parent buffer.
* Usually, this meta means we need to keep the parent buffer
* alive because one of the child memories is in use, which
* might not be the case if memory is deep copied or sub-regioned,
* but we can't tell, so keep the meta */
dmeta = gst_buffer_add_parent_buffer_meta (dest, smeta->buffer);
if (!dmeta)
return FALSE;
GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
"copy buffer reference metadata");
} else {
/* return FALSE, if transform type is not supported */
return FALSE;
}
return TRUE;
}
static void
_gst_parent_buffer_meta_free (GstParentBufferMeta * parent_meta,
GstBuffer * buffer)
{
GST_CAT_DEBUG (gst_parent_buffer_meta_debug,
"Dropping reference on buffer %p", parent_meta->buffer);
gst_buffer_unref (parent_meta->buffer);
}
static gboolean
_gst_parent_buffer_meta_init (GstParentBufferMeta * parent_meta,
gpointer params, GstBuffer * buffer)
{
static volatile gsize _init;
if (g_once_init_enter (&_init)) {
GST_DEBUG_CATEGORY_INIT (gst_parent_buffer_meta_debug, "parentbuffermeta",
0, "parentbuffermeta");
g_once_init_leave (&_init, 1);
}
parent_meta->buffer = NULL;
return TRUE;
}
/**
* gst_parent_buffer_meta_api_get_type: (attributes doc.skip=true)
*/
GType
gst_parent_buffer_meta_api_get_type (void)
{
static volatile GType type = 0;
static const gchar *tags[] = { NULL };
if (g_once_init_enter (&type)) {
GType _type = gst_meta_api_type_register ("GstParentBufferMetaAPI", tags);
g_once_init_leave (&type, _type);
}
return type;
}
/**
* gst_parent_buffer_meta_get_info:
*
* Gets the global #GstMetaInfo describing the #GstParentBufferMeta meta.
*
* Returns: (transfer none): The #GstMetaInfo
*
* Since: 1.6
*/
const GstMetaInfo *
gst_parent_buffer_meta_get_info (void)
{
static const GstMetaInfo *meta_info = NULL;
if (g_once_init_enter ((GstMetaInfo **) & meta_info)) {
const GstMetaInfo *meta =
gst_meta_register (gst_parent_buffer_meta_api_get_type (),
"GstParentBufferMeta",
sizeof (GstParentBufferMeta),
(GstMetaInitFunction) _gst_parent_buffer_meta_init,
(GstMetaFreeFunction) _gst_parent_buffer_meta_free,
_gst_parent_buffer_meta_transform);
g_once_init_leave ((GstMetaInfo **) & meta_info, (GstMetaInfo *) meta);
}
return meta_info;
}
GST_DEBUG_CATEGORY_STATIC (gst_reference_timestamp_meta_debug);
/**
* gst_buffer_add_reference_timestamp_meta:
* @buffer: (transfer none): a #GstBuffer
* @reference: (transfer none): identifier for the timestamp reference.
* @timestamp: timestamp
* @duration: duration, or %GST_CLOCK_TIME_NONE
*
* Adds a #GstReferenceTimestampMeta to @buffer that holds a @timestamp and
* optionally @duration based on a specific timestamp @reference. See the
* documentation of #GstReferenceTimestampMeta for details.
*
* Returns: (transfer none) (nullable): The #GstReferenceTimestampMeta that was added to the buffer
*
* Since: 1.14
*/
GstReferenceTimestampMeta *
gst_buffer_add_reference_timestamp_meta (GstBuffer * buffer,
GstCaps * reference, GstClockTime timestamp, GstClockTime duration)
{
GstReferenceTimestampMeta *meta;
g_return_val_if_fail (GST_IS_CAPS (reference), NULL);
g_return_val_if_fail (timestamp != GST_CLOCK_TIME_NONE, NULL);
meta =
(GstReferenceTimestampMeta *) gst_buffer_add_meta (buffer,
GST_REFERENCE_TIMESTAMP_META_INFO, NULL);
if (!meta)
return NULL;
meta->reference = gst_caps_ref (reference);
meta->timestamp = timestamp;
meta->duration = duration;
return meta;
}
/**
* gst_buffer_get_reference_timestamp_meta:
* @buffer: a #GstBuffer
* @reference: (allow-none): a reference #GstCaps
*
* Finds the first #GstReferenceTimestampMeta on @buffer that conforms to
* @reference. Conformance is tested by checking if the meta's reference is a
* subset of @reference.
*
* Buffers can contain multiple #GstReferenceTimestampMeta metadata items.
*
* Returns: (transfer none) (nullable): the #GstReferenceTimestampMeta or %NULL when there
* is no such metadata on @buffer.
*
* Since: 1.14
*/
GstReferenceTimestampMeta *
gst_buffer_get_reference_timestamp_meta (GstBuffer * buffer,
GstCaps * reference)
{
gpointer state = NULL;
GstMeta *meta;
const GstMetaInfo *info = GST_REFERENCE_TIMESTAMP_META_INFO;
while ((meta = gst_buffer_iterate_meta (buffer, &state))) {
if (meta->info->api == info->api) {
GstReferenceTimestampMeta *rmeta = (GstReferenceTimestampMeta *) meta;
if (!reference)
return rmeta;
if (gst_caps_is_subset (rmeta->reference, reference))
return rmeta;
}
}
return NULL;
}
static gboolean
_gst_reference_timestamp_meta_transform (GstBuffer * dest, GstMeta * meta,
GstBuffer * buffer, GQuark type, gpointer data)
{
GstReferenceTimestampMeta *dmeta, *smeta;
/* we copy over the reference timestamp meta, independent of transformation
* that happens. If it applied to the original buffer, it still applies to
* the new buffer as it refers to the time when the media was captured */
smeta = (GstReferenceTimestampMeta *) meta;
dmeta =
gst_buffer_add_reference_timestamp_meta (dest, smeta->reference,
smeta->timestamp, smeta->duration);
if (!dmeta)
return FALSE;
GST_CAT_DEBUG (gst_reference_timestamp_meta_debug,
"copy reference timestamp metadata from buffer %p to %p", buffer, dest);
return TRUE;
}
static void
_gst_reference_timestamp_meta_free (GstReferenceTimestampMeta * meta,
GstBuffer * buffer)
{
if (meta->reference)
gst_caps_unref (meta->reference);
}
static gboolean
_gst_reference_timestamp_meta_init (GstReferenceTimestampMeta * meta,
gpointer params, GstBuffer * buffer)
{
static volatile gsize _init;
if (g_once_init_enter (&_init)) {
GST_DEBUG_CATEGORY_INIT (gst_reference_timestamp_meta_debug,
"referencetimestampmeta", 0, "referencetimestampmeta");
g_once_init_leave (&_init, 1);
}
meta->reference = NULL;
meta->timestamp = GST_CLOCK_TIME_NONE;
meta->duration = GST_CLOCK_TIME_NONE;
return TRUE;
}
/**
* gst_reference_timestamp_meta_api_get_type: (attributes doc.skip=true)
*/
GType
gst_reference_timestamp_meta_api_get_type (void)
{
static volatile GType type = 0;
static const gchar *tags[] = { NULL };
if (g_once_init_enter (&type)) {
GType _type =
gst_meta_api_type_register ("GstReferenceTimestampMetaAPI", tags);
g_once_init_leave (&type, _type);
}
return type;
}
/**
* gst_reference_timestamp_meta_get_info:
*
* Gets the global #GstMetaInfo describing the #GstReferenceTimestampMeta meta.
*
* Returns: (transfer none): The #GstMetaInfo
*
* Since: 1.14
*/
const GstMetaInfo *
gst_reference_timestamp_meta_get_info (void)
{
static const GstMetaInfo *meta_info = NULL;
if (g_once_init_enter ((GstMetaInfo **) & meta_info)) {
const GstMetaInfo *meta =
gst_meta_register (gst_reference_timestamp_meta_api_get_type (),
"GstReferenceTimestampMeta",
sizeof (GstReferenceTimestampMeta),
(GstMetaInitFunction) _gst_reference_timestamp_meta_init,
(GstMetaFreeFunction) _gst_reference_timestamp_meta_free,
_gst_reference_timestamp_meta_transform);
g_once_init_leave ((GstMetaInfo **) & meta_info, (GstMetaInfo *) meta);
}
return meta_info;
}
/**
* gst_buffer_add_custom_meta:
* @buffer: (transfer none): a #GstBuffer
* @name: the registered name of the desired custom meta
*
* Creates and adds a #GstCustomMeta for the desired @name. @name must have
* been successfully registered with gst_meta_register_custom().
*
* Returns: (transfer none) (nullable): The #GstCustomMeta that was added to the buffer
*
* Since: 1.20
*/
GstCustomMeta *
gst_buffer_add_custom_meta (GstBuffer * buffer, const gchar * name)
{
GstCustomMeta *meta;
const GstMetaInfo *info;
g_return_val_if_fail (name != NULL, NULL);
g_return_val_if_fail (GST_IS_BUFFER (buffer), NULL);
info = gst_meta_get_info (name);
if (info == NULL || !gst_meta_info_is_custom (info))
return NULL;
meta = (GstCustomMeta *) gst_buffer_add_meta (buffer, info, NULL);
return meta;
}
/**
* gst_buffer_get_custom_meta:
* @buffer: a #GstBuffer
* @name: the registered name of the custom meta to retrieve.
*
* Finds the first #GstCustomMeta on @buffer for the desired @name.
*
* Returns: (transfer none) (nullable): the #GstCustomMeta
*
* Since: 1.20
*/
GstCustomMeta *
gst_buffer_get_custom_meta (GstBuffer * buffer, const gchar * name)
{
const GstMetaInfo *info;
g_return_val_if_fail (buffer != NULL, NULL);
g_return_val_if_fail (name != NULL, NULL);
info = gst_meta_get_info (name);
if (!info)
return NULL;
if (!gst_meta_info_is_custom (info))
return NULL;
return (GstCustomMeta *) gst_buffer_get_meta (buffer, info->api);
}
/**
* gst_buffer_ref: (skip)
* @buf: a #GstBuffer.
*
* Increases the refcount of the given buffer by one.
*
* Note that the refcount affects the writability
* of @buf and its metadata, see gst_buffer_is_writable().
* It is important to note that keeping additional references to
* GstBuffer instances can potentially increase the number
* of `memcpy` operations in a pipeline.
*
* Returns: (transfer full): @buf
*/
GstBuffer *
gst_buffer_ref (GstBuffer * buf)
{
return (GstBuffer *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (buf));
}
/**
* gst_buffer_unref: (skip)
* @buf: (transfer full): a #GstBuffer.
*
* Decreases the refcount of the buffer. If the refcount reaches 0, the buffer
* with the associated metadata and memory will be freed.
*/
void
gst_buffer_unref (GstBuffer * buf)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (buf));
}
/**
* gst_clear_buffer: (skip)
* @buf_ptr: a pointer to a #GstBuffer reference
*
* Clears a reference to a #GstBuffer.
*
* @buf_ptr must not be %NULL.
*
* If the reference is %NULL then this function does nothing. Otherwise, the
* reference count of the buffer is decreased and the pointer is set to %NULL.
*
* Since: 1.16
*/
void
gst_clear_buffer (GstBuffer ** buf_ptr)
{
gst_clear_mini_object ((GstMiniObject **) buf_ptr);
}
/**
* gst_buffer_copy: (skip)
* @buf: a #GstBuffer.
*
* Creates a copy of the given buffer. This will only copy the buffer's
* data to a newly allocated memory if needed (if the type of memory
* requires it), otherwise the underlying data is just referenced.
* Check gst_buffer_copy_deep() if you want to force the data
* to be copied to newly allocated memory.
*
* Returns: (transfer full): a new copy of @buf.
*/
GstBuffer *
gst_buffer_copy (const GstBuffer * buf)
{
return GST_BUFFER (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (buf)));
}
/**
* gst_buffer_replace: (skip)
* @obuf: (inout) (transfer full) (nullable): pointer to a pointer to
* a #GstBuffer to be replaced.
* @nbuf: (transfer none) (allow-none): pointer to a #GstBuffer that will
* replace the buffer pointed to by @obuf.
*
* Modifies a pointer to a #GstBuffer to point to a different #GstBuffer. The
* modification is done atomically (so this is useful for ensuring thread safety
* in some cases), and the reference counts are updated appropriately (the old
* buffer is unreffed, the new is reffed).
*
* Either @nbuf or the #GstBuffer pointed to by @obuf may be %NULL.
*
* Returns: %TRUE when @obuf was different from @nbuf.
*/
gboolean
gst_buffer_replace (GstBuffer ** obuf, GstBuffer * nbuf)
{
return gst_mini_object_replace ((GstMiniObject **) obuf,
(GstMiniObject *) nbuf);
}
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