A data-passing buffer type, supporting sub-buffers. More...

Inheritance diagram for Gst::Buffer:

Collaboration diagram for Gst::Buffer:

Public Member Functions
void	reference () const
	Increment the reference count for this object. More...
void	unreference () const
	Decrement the reference count for this object. More...
GstBuffer*	gobj ()
	Provides access to the underlying C instance. More...
const GstBuffer*	gobj () const
	Provides access to the underlying C instance. More...
GstBuffer*	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
Glib::RefPtr< Gst::Buffer >	copy () const
	Create a copy of the given buffer. More...
void	copy_into (Glib::RefPtr< Gst::Buffer > source_buffer, BufferCopyFlags flags, gsize offset, gsize size)
	Copies the information from src into dest. More...
Glib::RefPtr< Gst::Buffer >	create_writable ()
	Makes a writable buffer from the given buffer. More...
Glib::RefPtr< Gst::Memory >	get_memory (guint idx) const
	Get the memory block at index idx in buffer. More...
gsize	get_size () const
	Get the total size of the memory blocks in buffer. More...
Glib::RefPtr< Gst::Memory >	get_all_memory () const
	Get all the memory block in buffer. More...
gsize	fill (gsize offset, gconstpointer src, gsize size)
	Copy size bytes from src to buffer at offset. More...
Glib::RefPtr< Gst::Buffer >	append (const Glib::RefPtr< Gst::Buffer >& buf) const
	Append all the memory from buf2 to buf1. More...
Glib::RefPtr< Gst::Buffer >	append_region (const Glib::RefPtr< Gst::Buffer >& buf, gssize offset, gssize size) const
	Append size bytes at offset from buf2 to buf1. More...
void	replace_memory_range (guint idx, gint length, Glib::RefPtr< Gst::Memory > mem)
	Replaces length memory blocks in buffer starting at idx with mem. More...
void	remove_memory (guint idx)
	Remove the memory block in b at index i. More...
void	remove_all_memory ()
	Remove all the memory blocks in buffer. More...
gsize	memset (gsize offset, guint8 val, gsize size)
	Fill buf with size bytes with val starting from offset. More...
void	replace_memory (guint idx, Glib::RefPtr< Gst::Memory > mem)
	Replaces the memory block at index idx in buffer with mem. More...
gsize	extract (gsize offset, gpointer dest, gsize size)
	Copy size bytes starting from offset in buffer to dest. More...
int	memcmp (gsize offset, gconstpointer mem, gsize size)
	Compare size bytes starting from offset in buffer with the memory in mem. More...
ClockTime	get_pts () const
void	set_pts (const ClockTime& value)
ClockTime	get_dts () const
void	set_dts (const ClockTime& value)
ClockTime	get_duration () const
	Get duration of this buffer. More...
void	set_duration (const ClockTime& value)
bool	map (const Glib::RefPtr< Gst::MapInfo >& info, MapFlags flags)
	This function fills info with the Gst::MapInfo of all merged memory blocks in buffer. More...
void	unmap (const Glib::RefPtr< Gst::MapInfo >& info)
	Release the memory previously mapped with gst_buffer_map(). More...
guint64	get_offset () const
	Get the offset of this buffer. More...
guint64	get_offset_end () const
	Get the offset end of this buffer. More...
Public Member Functions inherited from Gst::MiniObject
void	reference () const
	Increment the reference count for this object. More...
void	unreference () const
	Decrement the reference count for this object. More...
GstMiniObject*	gobj ()
	Provides access to the underlying C instance. More...
const GstMiniObject*	gobj () const
	Provides access to the underlying C instance. More...
GstMiniObject*	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
	~MiniObject ()
guint	get_flags () const
void	set_flags (const guint& value)
bool	lock (LockFlags flags)
	Lock the mini-object with the specified access mode in flags. More...
void	unlock (LockFlags flags)
	Unlock the mini-object with the specified access mode in flags. More...
bool	is_writable () const
	If mini_object has the LOCKABLE flag set, check if the current EXCLUSIVE lock on object is the only one, this means that changes to the object will not be visible to any other object. More...
Glib::RefPtr< MiniObject >	create_writable ()
	Checks if a mini-object is writable. More...

Static Public Member Functions
static Glib::RefPtr< Buffer >	create ()
static Glib::RefPtr< Gst::Buffer >	create (guint size)

Protected Member Functions
	Buffer ()
void	operator delete (void*, std::size_t)
Protected Member Functions inherited from Gst::MiniObject
	MiniObject ()
void	operator delete (void*, std::size_t)

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gst::Buffer >	wrap (GstBuffer* object, bool take_copy=false)
	A Glib::wrap() method for this object. More...
Related Functions inherited from Gst::MiniObject
Glib::RefPtr< Gst::MiniObject >	wrap (GstMiniObject* object, bool take_copy=false)
	A Glib::wrap() method for this object. More...

Detailed Description

A data-passing buffer type, supporting sub-buffers.

Buffers are the basic unit of data transfer in GStreamer. The Gst::Buffer type provides all the state necessary to define a region of memory as part of a stream. Sub-buffers are also supported, allowing a smaller region of a buffer to become its own buffer, with mechanisms in place to ensure that neither memory space goes away prematurely.

Buffers are usually created with create(). After a buffer has been created one will typically allocate memory for it and set the size of the buffer data. The following example creates a buffer that can hold a given video frame with a given width, height and bits per plane.

Constructor & Destructor Documentation

Gst::Buffer::Buffer ( )

protected

Member Function Documentation

Glib::RefPtr<Gst::Buffer> Gst::Buffer::append

(

const Glib::RefPtr< Gst::Buffer >&

buf

)

const

Append all the memory from buf2 to buf1.

The result buffer will contain a concatenation of the memory of buf1 and buf2.

Parameters

buf2	The second source Gst::Buffer to append.

Returns

The new Gst::Buffer that contains the memory of the two source buffers.

Glib::RefPtr<Gst::Buffer> Gst::Buffer::append_region	(	const Glib::RefPtr< Gst::Buffer >&	buf,
		gssize	offset,
		gssize	size
	)		const

Append 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.

Parameters

buf2	The second source Gst::Buffer to append.
offset	The offset in buf2.
size	The size or -1 of buf2.

Returns

The new Gst::Buffer that contains the memory of the two source buffers.

Glib::RefPtr<Gst::Buffer> Gst::Buffer::copy

(

)

const

Create a copy of the given buffer.

This will also make a newly allocated copy of the data the source buffer contains.

Returns

The Gst::Buffer copy.

void Gst::Buffer::copy_into	(	Glib::RefPtr< Gst::Buffer >	source_buffer,
		BufferCopyFlags	flags,
		gsize	offset,
		gsize	size
	)

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.

Parameters

src	A source Gst::Buffer.
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.

Returns

true if the copying succeeded, false otherwise.

static Glib::RefPtr<Buffer> Gst::Buffer::create ( )

static

static Glib::RefPtr<Gst::Buffer> Gst::Buffer::create ( guint  size )

static

Glib::RefPtr<Gst::Buffer> Gst::Buffer::create_writable

(

)

Makes a writable buffer from the given buffer.

If the source buffer is already writable, this will simply return the same buffer. A copy will otherwise be made.

Returns

A buffer (possibly the same pointer) that is writable.

gsize Gst::Buffer::extract	(	gsize	offset,
		gpointer	dest,
		gsize	size
	)

Copy size bytes starting from offset in buffer to dest.

Parameters

offset	The offset to extract.
dest	The destination address.
size	The size to extract.

Returns

The amount of bytes extracted. This value can be lower than size when buffer did not contain enough data.

gsize Gst::Buffer::fill	(	gsize	offset,
		gconstpointer	src,
		gsize	size
	)

Copy size bytes from src to buffer at offset.

Parameters

offset	The offset to fill.
src	The source address.
size	The size to fill.

Returns

The amount of bytes copied. This value can be lower than size when buffer did not contain enough data.

Glib::RefPtr<Gst::Memory> Gst::Buffer::get_all_memory

(

)

const

Get all the memory block in buffer.

The memory blocks will be merged into one large Gst::Memory.

Returns

A Gst::Memory that contains the merged memory. Use gst_memory_unref() after usage.

ClockTime Gst::Buffer::get_dts

(

)

const

ClockTime Gst::Buffer::get_duration

(

)

const

Get duration of this buffer.

Returns

he duration in nanoseconds (as a Gst::ClockTime) of the data in the buffer. Value will be Gst::CLOCK_TIME_NONE if the duration is unknown.

Glib::RefPtr<Gst::Memory> Gst::Buffer::get_memory

(

guint

idx

)

const

Get the memory block at index idx in buffer.

Parameters

idx

An index.

Returns

A Gst::Memory that contains the data of the memory block at idx. Use gst_memory_unref() after usage.

guint64 Gst::Buffer::get_offset

(

)

const

Get the offset of this buffer.

Returns

The offset in the source file of the beginning of this buffer.

guint64 Gst::Buffer::get_offset_end

(

)

const

Get the offset end of this buffer.

Returns

The offset in the source file of the end of this buffer.

ClockTime Gst::Buffer::get_pts

(

)

const

gsize Gst::Buffer::get_size

(

)

const

Get the total size of the memory blocks in buffer.

Returns

Total size of the memory blocks in buffer.

GstBuffer* Gst::Buffer::gobj

(

)

Provides access to the underlying C instance.

const GstBuffer* Gst::Buffer::gobj

(

)

const

Provides access to the underlying C instance.

GstBuffer* Gst::Buffer::gobj_copy

(

)

const

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

bool Gst::Buffer::map	(	const Glib::RefPtr< Gst::MapInfo >&	info,
		MapFlags	flags
	)

This function fills info with the Gst::MapInfo 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.

Parameters

info	Info about the mapping.
flags	Flags for the mapping.

Returns

true if the map succeeded and info contains valid data.

int Gst::Buffer::memcmp	(	gsize	offset,
		gconstpointer	mem,
		gsize	size
	)

Compare size bytes starting from offset in buffer with the memory in mem.

Parameters

offset	The offset in buffer.
mem	The memory to compare.
size	The size to compare.

Returns

0 if the memory is equal.

gsize Gst::Buffer::memset	(	gsize	offset,
		guint8	val,
		gsize	size
	)

Fill buf with size bytes with val starting from offset.

Parameters

offset	The offset in buffer.
val	The value to set.
size	The size to set.

Returns

The amount of bytes filled. This value can be lower than size when buffer did not contain enough data.

void Gst::Buffer::operator delete ( void *  , std::size_t    )

protected

void Gst::Buffer::reference

(

)

const

Increment the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

void Gst::Buffer::remove_all_memory

(

)

Remove all the memory blocks in buffer.

void Gst::Buffer::remove_memory

(

guint

idx

)

Remove the memory block in b at index i.

Parameters

idx

An index.

void Gst::Buffer::replace_memory	(	guint	idx,
		Glib::RefPtr< Gst::Memory >	mem
	)

Replaces the memory block at index idx in buffer with mem.

Parameters

idx	An index.
mem	A Gst::Memory.

void Gst::Buffer::replace_memory_range	(	guint	idx,
		gint	length,
		Glib::RefPtr< Gst::Memory >	mem
	)

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.

Parameters

idx	An index.
length	A length should not be 0.
mem	A Gst::Memory.

void Gst::Buffer::set_dts

(

const ClockTime&

value

)

void Gst::Buffer::set_duration

(

const ClockTime&

value

)

void Gst::Buffer::set_pts

(

const ClockTime&

value

)

void Gst::Buffer::unmap

(

const Glib::RefPtr< Gst::MapInfo >&

info

)

Release the memory previously mapped with gst_buffer_map().

Parameters

info	A Gst::MapInfo.

void Gst::Buffer::unreference

(

)

const

Decrement the reference count for this object.

You should never need to do this manually - use the object via a RefPtr instead.

Friends And Related Function Documentation

Glib::RefPtr< Gst::Buffer > wrap ( GstBuffer *  object, bool  take_copy = false  )

related

A Glib::wrap() method for this object.

Parameters

object	The C instance.
take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns

A C++ instance that wraps this C instance.

---

The documentation for this class was generated from the following file:

• gstreamermm/buffer.h