gstreamer/gst/gstbuffer.h
Stéphane Cerveau 8a20d66b10 gstbuffer: update documentation
remove unclear documentation about GST_BUFFER_FLAG_MARKER
2019-11-18 00:15:31 +00:00

805 lines
29 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstbuffer.h: Header for GstBuffer object
*
* 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.
*/
#ifndef __GST_BUFFER_H__
#define __GST_BUFFER_H__
#include <gst/gstminiobject.h>
#include <gst/gstclock.h>
#include <gst/gstallocator.h>
#include <gst/gstcaps.h>
G_BEGIN_DECLS
GST_API GType _gst_buffer_type;
typedef struct _GstBuffer GstBuffer;
typedef struct _GstBufferPool GstBufferPool;
#include <gst/gstmeta.h>
#define GST_TYPE_BUFFER (_gst_buffer_type)
#define GST_IS_BUFFER(obj) (GST_IS_MINI_OBJECT_TYPE(obj, GST_TYPE_BUFFER))
#define GST_BUFFER_CAST(obj) ((GstBuffer *)(obj))
#define GST_BUFFER(obj) (GST_BUFFER_CAST(obj))
/**
* GST_BUFFER_FLAGS:
* @buf: a #GstBuffer.
*
* A flags word containing #GstBufferFlags flags set on this buffer.
*/
#define GST_BUFFER_FLAGS(buf) GST_MINI_OBJECT_FLAGS(buf)
/**
* GST_BUFFER_FLAG_IS_SET:
* @buf: a #GstBuffer.
* @flag: the #GstBufferFlags flag to check.
*
* Gives the status of a specific flag on a buffer.
*/
#define GST_BUFFER_FLAG_IS_SET(buf,flag) GST_MINI_OBJECT_FLAG_IS_SET (buf, flag)
/**
* GST_BUFFER_FLAG_SET:
* @buf: a #GstBuffer.
* @flag: the #GstBufferFlags flag to set.
*
* Sets a buffer flag on a buffer.
*/
#define GST_BUFFER_FLAG_SET(buf,flag) GST_MINI_OBJECT_FLAG_SET (buf, flag)
/**
* GST_BUFFER_FLAG_UNSET:
* @buf: a #GstBuffer.
* @flag: the #GstBufferFlags flag to clear.
*
* Clears a buffer flag.
*/
#define GST_BUFFER_FLAG_UNSET(buf,flag) GST_MINI_OBJECT_FLAG_UNSET (buf, flag)
/**
* GST_BUFFER_PTS:
* @buf: a #GstBuffer.:
*
* The presentation timestamp (pts) in nanoseconds (as a #GstClockTime)
* of the data in the buffer. This is the timestamp when the media should be
* presented to the user.
* Value will be %GST_CLOCK_TIME_NONE if the pts is unknown.
*/
#define GST_BUFFER_PTS(buf) (GST_BUFFER_CAST(buf)->pts)
/**
* GST_BUFFER_DTS:
* @buf: a #GstBuffer.:
*
* The decoding timestamp (dts) in nanoseconds (as a #GstClockTime)
* of the data in the buffer. This is the timestamp when the media should be
* decoded or processed otherwise.
* Value will be %GST_CLOCK_TIME_NONE if the dts is unknown.
*/
#define GST_BUFFER_DTS(buf) (GST_BUFFER_CAST(buf)->dts)
/**
* GST_BUFFER_DTS_OR_PTS:
* @buf: a #GstBuffer.:
*
* Returns the buffer decoding timestamp (dts) if valid, else the buffer
* presentation time (pts)
*
* Since: 1.8
*/
#define GST_BUFFER_DTS_OR_PTS(buf) (GST_BUFFER_DTS_IS_VALID(buf) ? GST_BUFFER_DTS(buf) : GST_BUFFER_PTS (buf))
/**
* GST_BUFFER_DURATION:
* @buf: a #GstBuffer.
*
* The duration in nanoseconds (as a #GstClockTime) of the data in the buffer.
* Value will be %GST_CLOCK_TIME_NONE if the duration is unknown.
*/
#define GST_BUFFER_DURATION(buf) (GST_BUFFER_CAST(buf)->duration)
/**
* GST_BUFFER_OFFSET:
* @buf: a #GstBuffer.
*
* The offset in the source file of the beginning of this buffer.
*/
#define GST_BUFFER_OFFSET(buf) (GST_BUFFER_CAST(buf)->offset)
/**
* GST_BUFFER_OFFSET_END:
* @buf: a #GstBuffer.
*
* The offset in the source file of the end of this buffer.
*/
#define GST_BUFFER_OFFSET_END(buf) (GST_BUFFER_CAST(buf)->offset_end)
/**
* GST_BUFFER_OFFSET_NONE:
*
* Constant for no-offset return results.
*/
#define GST_BUFFER_OFFSET_NONE ((guint64)-1)
/**
* GST_BUFFER_DURATION_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the duration is known.
*/
#define GST_BUFFER_DURATION_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer)))
/**
* GST_BUFFER_PTS_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the pts is known.
*/
#define GST_BUFFER_PTS_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_PTS (buffer)))
/**
* GST_BUFFER_DTS_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the dts is known.
*/
#define GST_BUFFER_DTS_IS_VALID(buffer) (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DTS (buffer)))
/**
* GST_BUFFER_OFFSET_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the start offset is known.
*/
#define GST_BUFFER_OFFSET_IS_VALID(buffer) (GST_BUFFER_OFFSET (buffer) != GST_BUFFER_OFFSET_NONE)
/**
* GST_BUFFER_OFFSET_END_IS_VALID:
* @buffer: a #GstBuffer
*
* Tests if the end offset is known.
*/
#define GST_BUFFER_OFFSET_END_IS_VALID(buffer) (GST_BUFFER_OFFSET_END (buffer) != GST_BUFFER_OFFSET_NONE)
/**
* GST_BUFFER_IS_DISCONT:
* @buffer: a #GstBuffer
*
* Tests if the buffer marks a discontinuity in the stream.
*/
#define GST_BUFFER_IS_DISCONT(buffer) (GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DISCONT))
/**
* GstBufferFlags:
* @GST_BUFFER_FLAG_LIVE: the buffer is live data and should be discarded in
* the PAUSED state.
* @GST_BUFFER_FLAG_DECODE_ONLY: the buffer contains data that should be dropped
* because it will be clipped against the segment
* boundaries or because it does not contain data
* that should be shown to the user.
* @GST_BUFFER_FLAG_DISCONT: the buffer marks a data discontinuity in the stream.
* This typically occurs after a seek or a dropped buffer
* from a live or network source.
* @GST_BUFFER_FLAG_RESYNC: the buffer timestamps might have a discontinuity
* and this buffer is a good point to resynchronize.
* @GST_BUFFER_FLAG_CORRUPTED: the buffer data is corrupted.
* @GST_BUFFER_FLAG_MARKER: the buffer contains a media specific marker. for
* video this is the end of a frame boundary, for audio
* this is the start of a talkspurt.
* @GST_BUFFER_FLAG_HEADER: the buffer contains header information that is
* needed to decode the following data.
* @GST_BUFFER_FLAG_GAP: the buffer has been created to fill a gap in the
* stream and contains media neutral data (elements can
* switch to optimized code path that ignores the buffer
* content).
* @GST_BUFFER_FLAG_DROPPABLE: the buffer can be dropped without breaking the
* stream, for example to reduce bandwidth.
* @GST_BUFFER_FLAG_DELTA_UNIT: this unit cannot be decoded independently.
* @GST_BUFFER_FLAG_TAG_MEMORY: this flag is set when memory of the buffer
* is added/removed
* @GST_BUFFER_FLAG_SYNC_AFTER: Elements which write to disk or permanent
* storage should ensure the data is synced after
* writing the contents of this buffer. (Since: 1.6)
* @GST_BUFFER_FLAG_NON_DROPPABLE: This buffer is important and should not be dropped.
* This can be used to mark important buffers, e.g. to flag
* RTP packets carrying keyframes or codec setup data for RTP
* Forward Error Correction purposes, or to prevent still video
* frames from being dropped by elements due to QoS. (Since: 1.14)
* @GST_BUFFER_FLAG_LAST: additional media specific flags can be added starting from
* this flag.
*
* A set of buffer flags used to describe properties of a #GstBuffer.
*/
typedef enum {
GST_BUFFER_FLAG_LIVE = (GST_MINI_OBJECT_FLAG_LAST << 0),
GST_BUFFER_FLAG_DECODE_ONLY = (GST_MINI_OBJECT_FLAG_LAST << 1),
GST_BUFFER_FLAG_DISCONT = (GST_MINI_OBJECT_FLAG_LAST << 2),
GST_BUFFER_FLAG_RESYNC = (GST_MINI_OBJECT_FLAG_LAST << 3),
GST_BUFFER_FLAG_CORRUPTED = (GST_MINI_OBJECT_FLAG_LAST << 4),
GST_BUFFER_FLAG_MARKER = (GST_MINI_OBJECT_FLAG_LAST << 5),
GST_BUFFER_FLAG_HEADER = (GST_MINI_OBJECT_FLAG_LAST << 6),
GST_BUFFER_FLAG_GAP = (GST_MINI_OBJECT_FLAG_LAST << 7),
GST_BUFFER_FLAG_DROPPABLE = (GST_MINI_OBJECT_FLAG_LAST << 8),
GST_BUFFER_FLAG_DELTA_UNIT = (GST_MINI_OBJECT_FLAG_LAST << 9),
GST_BUFFER_FLAG_TAG_MEMORY = (GST_MINI_OBJECT_FLAG_LAST << 10),
GST_BUFFER_FLAG_SYNC_AFTER = (GST_MINI_OBJECT_FLAG_LAST << 11),
GST_BUFFER_FLAG_NON_DROPPABLE = (GST_MINI_OBJECT_FLAG_LAST << 12),
GST_BUFFER_FLAG_LAST = (GST_MINI_OBJECT_FLAG_LAST << 16)
} GstBufferFlags;
/**
* GstBuffer:
* @mini_object: the parent structure
* @pool: pointer to the pool owner of the buffer
* @pts: presentation timestamp of the buffer, can be #GST_CLOCK_TIME_NONE when the
* pts is not known or relevant. The pts contains the timestamp when the
* media should be presented to the user.
* @dts: decoding timestamp of the buffer, can be #GST_CLOCK_TIME_NONE when the
* dts is not known or relevant. The dts contains the timestamp when the
* media should be processed.
* @duration: duration in time of the buffer data, can be #GST_CLOCK_TIME_NONE
* when the duration is not known or relevant.
* @offset: a media specific offset for the buffer data.
* For video frames, this is the frame number of this buffer.
* For audio samples, this is the offset of the first sample in this buffer.
* For file data or compressed data this is the byte offset of the first
* byte in this buffer.
* @offset_end: the last offset contained in this buffer. It has the same
* format as @offset.
*
* The structure of a #GstBuffer. Use the associated macros to access the public
* variables.
*/
struct _GstBuffer {
GstMiniObject mini_object;
/*< public >*/ /* with COW */
GstBufferPool *pool;
/* timestamp */
GstClockTime pts;
GstClockTime dts;
GstClockTime duration;
/* media specific offset */
guint64 offset;
guint64 offset_end;
};
GST_API
GType gst_buffer_get_type (void);
GST_API
guint gst_buffer_get_max_memory (void);
/* allocation */
GST_API
GstBuffer * gst_buffer_new (void);
GST_API
GstBuffer * gst_buffer_new_allocate (GstAllocator * allocator, gsize size,
GstAllocationParams * params);
GST_API
GstBuffer * gst_buffer_new_wrapped_full (GstMemoryFlags flags, gpointer data, gsize maxsize,
gsize offset, gsize size, gpointer user_data,
GDestroyNotify notify);
GST_API
GstBuffer * gst_buffer_new_wrapped (gpointer data, gsize size);
GST_API
GstBuffer * gst_buffer_new_wrapped_bytes (GBytes * bytes);
/* memory blocks */
GST_API
guint gst_buffer_n_memory (GstBuffer *buffer);
GST_API
void gst_buffer_insert_memory (GstBuffer *buffer, gint idx, GstMemory *mem);
GST_API
void gst_buffer_replace_memory_range (GstBuffer *buffer, guint idx, gint length, GstMemory *mem);
GST_API
GstMemory * gst_buffer_peek_memory (GstBuffer *buffer, guint idx);
GST_API
GstMemory * gst_buffer_get_memory_range (GstBuffer *buffer, guint idx, gint length);
GST_API
void gst_buffer_remove_memory_range (GstBuffer *buffer, guint idx, gint length);
GST_API
void gst_buffer_prepend_memory (GstBuffer *buffer, GstMemory *mem);
GST_API
void gst_buffer_append_memory (GstBuffer *buffer, GstMemory *mem);
GST_API
void gst_buffer_replace_memory (GstBuffer *buffer, guint idx, GstMemory *mem);
GST_API
void gst_buffer_replace_all_memory (GstBuffer *buffer, GstMemory *mem);
GST_API
GstMemory * gst_buffer_get_memory (GstBuffer *buffer, guint idx);
GST_API
GstMemory * gst_buffer_get_all_memory (GstBuffer *buffer);
GST_API
void gst_buffer_remove_memory (GstBuffer *buffer, guint idx);
GST_API
void gst_buffer_remove_all_memory (GstBuffer *buffer);
GST_API
gboolean gst_buffer_find_memory (GstBuffer *buffer, gsize offset, gsize size,
guint *idx, guint *length, gsize *skip);
GST_API
gboolean gst_buffer_is_memory_range_writable (GstBuffer *buffer, guint idx, gint length);
GST_API
gboolean gst_buffer_is_all_memory_writable (GstBuffer *buffer);
GST_API
gsize gst_buffer_fill (GstBuffer *buffer, gsize offset,
gconstpointer src, gsize size);
GST_API
gsize gst_buffer_extract (GstBuffer *buffer, gsize offset,
gpointer dest, gsize size);
GST_API
gint gst_buffer_memcmp (GstBuffer *buffer, gsize offset,
gconstpointer mem, gsize size);
GST_API
gsize gst_buffer_memset (GstBuffer *buffer, gsize offset,
guint8 val, gsize size);
GST_API
gsize gst_buffer_get_sizes_range (GstBuffer *buffer, guint idx, gint length,
gsize *offset, gsize *maxsize);
GST_API
gboolean gst_buffer_resize_range (GstBuffer *buffer, guint idx, gint length,
gssize offset, gssize size);
GST_API
gsize gst_buffer_get_sizes (GstBuffer *buffer, gsize *offset, gsize *maxsize);
GST_API
gsize gst_buffer_get_size (GstBuffer *buffer);
GST_API
void gst_buffer_resize (GstBuffer *buffer, gssize offset, gssize size);
GST_API
void gst_buffer_set_size (GstBuffer *buffer, gssize size);
GST_API
gboolean gst_buffer_map_range (GstBuffer *buffer, guint idx, gint length,
GstMapInfo *info, GstMapFlags flags);
GST_API
gboolean gst_buffer_map (GstBuffer *buffer, GstMapInfo *info, GstMapFlags flags);
GST_API
void gst_buffer_unmap (GstBuffer *buffer, GstMapInfo *info);
GST_API
void gst_buffer_extract_dup (GstBuffer *buffer, gsize offset,
gsize size, gpointer *dest,
gsize *dest_size);
GST_API
GstBufferFlags gst_buffer_get_flags (GstBuffer * buffer);
GST_API
gboolean gst_buffer_has_flags (GstBuffer * buffer, GstBufferFlags flags);
GST_API
gboolean gst_buffer_set_flags (GstBuffer * buffer, GstBufferFlags flags);
GST_API
gboolean gst_buffer_unset_flags (GstBuffer * buffer, GstBufferFlags flags);
/* refcounting */
/**
* 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
*/
static inline GstBuffer* gst_buffer_ref(GstBuffer* buf);
static inline 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.
*/
static inline void gst_buffer_unref(GstBuffer* buf);
static inline 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
*/
static inline void
gst_clear_buffer (GstBuffer ** buf_ptr)
{
gst_clear_mini_object ((GstMiniObject **) buf_ptr);
}
/* copy buffer */
/**
* gst_buffer_copy: (skip)
* @buf: a #GstBuffer.
*
* Create 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.
*/
static inline GstBuffer* gst_buffer_copy(const GstBuffer* buf);
static inline GstBuffer *
gst_buffer_copy (const GstBuffer * buf)
{
return GST_BUFFER (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (buf)));
}
GST_API
GstBuffer * gst_buffer_copy_deep (const GstBuffer * buf);
/**
* GstBufferCopyFlags:
* @GST_BUFFER_COPY_NONE: copy nothing
* @GST_BUFFER_COPY_FLAGS: flag indicating that buffer flags should be copied
* @GST_BUFFER_COPY_TIMESTAMPS: flag indicating that buffer pts, dts,
* duration, offset and offset_end should be copied
* @GST_BUFFER_COPY_MEMORY: flag indicating that buffer memory should be reffed
* and appended to already existing memory. Unless the memory is marked as
* NO_SHARE, no actual copy of the memory is made but it is simply reffed.
* Add @GST_BUFFER_COPY_DEEP to force a real copy.
* @GST_BUFFER_COPY_MERGE: flag indicating that buffer memory should be
* merged
* @GST_BUFFER_COPY_META: flag indicating that buffer meta should be
* copied
* @GST_BUFFER_COPY_DEEP: flag indicating that memory should always be
* copied instead of reffed (Since: 1.2)
*
* A set of flags that can be provided to the gst_buffer_copy_into()
* function to specify which items should be copied.
*/
typedef enum {
GST_BUFFER_COPY_NONE = 0,
GST_BUFFER_COPY_FLAGS = (1 << 0),
GST_BUFFER_COPY_TIMESTAMPS = (1 << 1),
GST_BUFFER_COPY_META = (1 << 2),
GST_BUFFER_COPY_MEMORY = (1 << 3),
GST_BUFFER_COPY_MERGE = (1 << 4),
GST_BUFFER_COPY_DEEP = (1 << 5)
} GstBufferCopyFlags;
/**
* GST_BUFFER_COPY_METADATA: (value 7) (type GstBufferCopyFlags)
*
* Combination of all possible metadata fields that can be copied with
* gst_buffer_copy_into().
*/
#define GST_BUFFER_COPY_METADATA ((GstBufferCopyFlags) (GST_BUFFER_COPY_FLAGS |\
GST_BUFFER_COPY_TIMESTAMPS | GST_BUFFER_COPY_META))
/**
* GST_BUFFER_COPY_ALL: (value 15) (type GstBufferCopyFlags)
*
* Combination of all possible fields that can be copied with
* gst_buffer_copy_into().
*/
#define GST_BUFFER_COPY_ALL ((GstBufferCopyFlags)(GST_BUFFER_COPY_METADATA | GST_BUFFER_COPY_MEMORY))
/* copies memory or metadata into newly allocated buffer */
GST_API
gboolean gst_buffer_copy_into (GstBuffer *dest, GstBuffer *src,
GstBufferCopyFlags flags,
gsize offset, gsize size);
/**
* gst_buffer_is_writable:
* @buf: a #GstBuffer
*
* Tests if you can safely write to a buffer's metadata or its memory array.
* It is only safe to change buffer metadata when the current reference is
* writable, i.e. nobody can see the modifications you will make.
*/
#define gst_buffer_is_writable(buf) gst_mini_object_is_writable (GST_MINI_OBJECT_CAST (buf))
/**
* gst_buffer_make_writable:
* @buf: (transfer full): a #GstBuffer
*
* Returns a writable copy of @buf. If the source buffer is
* already writable, this will simply return the same buffer.
*
* Use this function to ensure that a buffer can be safely modified before
* making changes to it, including changing the metadata such as PTS/DTS.
*
* If the reference count of the source buffer @buf is exactly one, the caller
* is the sole owner and this function will return the buffer object unchanged.
*
* If there is more than one reference on the object, a copy will be made using
* gst_buffer_copy(). The passed-in @buf will be unreffed in that case, and the
* caller will now own a reference to the new returned buffer object. Note
* that this just copies the buffer structure itself, the underlying memory is
* not copied if it can be shared amongst multiple buffers.
*
* In short, this function unrefs the buf in the argument and refs the buffer
* that it returns. Don't access the argument after calling this function unless
* you have an additional reference to it.
*
* Returns: (transfer full): a writable buffer which may or may not be the
* same as @buf
*/
#define gst_buffer_make_writable(buf) GST_BUFFER_CAST (gst_mini_object_make_writable (GST_MINI_OBJECT_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.
*/
static inline gboolean gst_buffer_replace(GstBuffer** obuf, GstBuffer* nbuf);
static inline gboolean
gst_buffer_replace (GstBuffer **obuf, GstBuffer *nbuf)
{
return gst_mini_object_replace ((GstMiniObject **) obuf, (GstMiniObject *) nbuf);
}
/* creating a region */
GST_API
GstBuffer* gst_buffer_copy_region (GstBuffer *parent, GstBufferCopyFlags flags,
gsize offset, gsize size);
/* append two buffers */
GST_API
GstBuffer* gst_buffer_append_region (GstBuffer *buf1, GstBuffer *buf2,
gssize offset, gssize size);
GST_API
GstBuffer* gst_buffer_append (GstBuffer *buf1, GstBuffer *buf2);
/* metadata */
#include <gst/gstmeta.h>
/**
* GstBufferForeachMetaFunc:
* @buffer: a #GstBuffer
* @meta: (out) (nullable): a pointer to a #GstMeta
* @user_data: user data passed to gst_buffer_foreach_meta()
*
* A function that will be called from gst_buffer_foreach_meta(). The @meta
* field will point to a the reference of the meta.
*
* @buffer should not be modified from this callback.
*
* When this function returns %TRUE, the next meta will be
* returned. When %FALSE is returned, gst_buffer_foreach_meta() will return.
*
* When @meta is set to %NULL, the item will be removed from the buffer.
*
* Returns: %FALSE when gst_buffer_foreach_meta() should stop
*/
typedef gboolean (*GstBufferForeachMetaFunc) (GstBuffer *buffer, GstMeta **meta,
gpointer user_data);
GST_API
GstMeta * gst_buffer_get_meta (GstBuffer *buffer, GType api);
GST_API
guint gst_buffer_get_n_meta (GstBuffer *buffer, GType api_type);
GST_API
GstMeta * gst_buffer_add_meta (GstBuffer *buffer, const GstMetaInfo *info,
gpointer params);
GST_API
gboolean gst_buffer_remove_meta (GstBuffer *buffer, GstMeta *meta);
GST_API
GstMeta * gst_buffer_iterate_meta (GstBuffer *buffer, gpointer *state);
GST_API
GstMeta * gst_buffer_iterate_meta_filtered (GstBuffer * buffer,
gpointer * state,
GType meta_api_type);
GST_API
gboolean gst_buffer_foreach_meta (GstBuffer *buffer,
GstBufferForeachMetaFunc func,
gpointer user_data);
/**
* gst_value_set_buffer:
* @v: a #GValue to receive the data
* @b: (transfer none): a #GstBuffer to assign to the GstValue
*
* Sets @b as the value of @v. Caller retains reference to buffer.
*/
#define gst_value_set_buffer(v,b) g_value_set_boxed((v),(b))
/**
* gst_value_take_buffer:
* @v: a #GValue to receive the data
* @b: (transfer full): a #GstBuffer to assign to the GstValue
*
* Sets @b as the value of @v. Caller gives away reference to buffer.
*/
#define gst_value_take_buffer(v,b) g_value_take_boxed(v,(b))
/**
* gst_value_get_buffer:
* @v: a #GValue to query
*
* Receives a #GstBuffer as the value of @v. Does not return a reference to
* the buffer, so the pointer is only valid for as long as the caller owns
* a reference to @v.
*
* Returns: (transfer none): buffer
*/
#define gst_value_get_buffer(v) GST_BUFFER_CAST (g_value_get_boxed(v))
typedef struct _GstParentBufferMeta GstParentBufferMeta;
/**
* GstParentBufferMeta:
* @parent: the parent #GstMeta structure
* @buffer: the #GstBuffer on which a reference is being held.
*
* The #GstParentBufferMeta is a #GstMeta 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
*/
struct _GstParentBufferMeta
{
GstMeta parent;
/*< public >*/
GstBuffer *buffer;
};
GST_API
GType gst_parent_buffer_meta_api_get_type (void);
#ifndef GST_DISABLE_DEPRECATED
#define GST_TYPE_PARENT_BUFFER_META_API_TYPE GST_PARENT_BUFFER_META_API_TYPE
#endif
#define GST_PARENT_BUFFER_META_API_TYPE (gst_parent_buffer_meta_api_get_type())
/**
* gst_buffer_get_parent_buffer_meta:
* @b: a #GstBuffer
*
* Find and return a #GstParentBufferMeta if one exists on the
* buffer
*/
#define gst_buffer_get_parent_buffer_meta(b) \
((GstParentBufferMeta*)gst_buffer_get_meta((b),GST_PARENT_BUFFER_META_API_TYPE))
GST_API
const GstMetaInfo *gst_parent_buffer_meta_get_info (void);
#define GST_PARENT_BUFFER_META_INFO (gst_parent_buffer_meta_get_info())
/* implementation */
GST_API
GstParentBufferMeta *gst_buffer_add_parent_buffer_meta (GstBuffer *buffer,
GstBuffer *ref);
typedef struct _GstReferenceTimestampMeta GstReferenceTimestampMeta;
/**
* GstReferenceTimestampMeta:
* @parent: the parent #GstMeta structure
* @reference: identifier for the timestamp reference.
* @timestamp: timestamp
* @duration: duration, or %GST_CLOCK_TIME_NONE
*
* #GstReferenceTimestampMeta can be used to attach alternative timestamps and
* possibly durations to a #GstBuffer. These are generally not according to
* the pipeline clock and could be e.g. the NTP timestamp when the media was
* captured.
*
* The reference is stored as a #GstCaps in @reference. Examples of valid
* references would be "timestamp/x-drivername-stream" for timestamps that are locally
* generated by some driver named "drivername" when generating the stream,
* e.g. based on a frame counter, or "timestamp/x-ntp, host=pool.ntp.org,
* port=123" for timestamps based on a specific NTP server.
*
* Since: 1.14
*/
struct _GstReferenceTimestampMeta
{
GstMeta parent;
/*< public >*/
GstCaps *reference;
GstClockTime timestamp, duration;
};
GST_API
GType gst_reference_timestamp_meta_api_get_type (void);
#define GST_REFERENCE_TIMESTAMP_META_API_TYPE (gst_reference_timestamp_meta_api_get_type())
GST_API
const GstMetaInfo *gst_reference_timestamp_meta_get_info (void);
#define GST_REFERENCE_TIMESTAMP_META_INFO (gst_reference_timestamp_meta_get_info())
/* implementation */
GST_API
GstReferenceTimestampMeta * gst_buffer_add_reference_timestamp_meta (GstBuffer * buffer,
GstCaps * reference,
GstClockTime timestamp,
GstClockTime duration);
GST_API
GstReferenceTimestampMeta * gst_buffer_get_reference_timestamp_meta (GstBuffer * buffer,
GstCaps * reference);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBuffer, gst_buffer_unref)
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBufferPool, gst_object_unref)
G_END_DECLS
#endif /* __GST_BUFFER_H__ */