A base class for audio audioringbuffer implementations. More...

Inheritance diagram for Gst::AudioRingBuffer:

Collaboration diagram for Gst::AudioRingBuffer:

Public Types
typedef sigc::slot< void, const Glib::ArrayHandle < guint8 >&, guint >	SlotFill
	For example, bool on_fill(const Glib::RefPtr<Gst::AudioRingBuffer>& rbuf, const std::vector<guint8>& data, guint len);. More...

Public Member Functions
virtual	~AudioRingBuffer ()
GstAudioRingBuffer*	gobj ()
	Provides access to the underlying C GObject. More...
const GstAudioRingBuffer*	gobj () const
	Provides access to the underlying C GObject. More...
GstAudioRingBuffer*	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
void	set_fill_slot (const SlotFill& slot)
	Sets the given fill slot on the buffer. More...
bool	acquire (Gst::AudioRingBufferSpec& spec)
	Allocate the resources for the ringbuffer. More...
bool	release ()
	Free the resources of the ringbuffer. More...
bool	is_acquired () const
	Check if the ringbuffer is acquired and ready to use. More...
bool	activate (bool active)
	Activate buf to start or stop pulling data. More...
bool	is_active () const
	Check if buf is activated. More...
bool	start ()
	Start processing samples from the ringbuffer. More...
bool	pause ()
	Pause processing samples from the ringbuffer. More...
bool	stop ()
	Stop processing samples from the ringbuffer. More...
guint	get_delay () const
	Get the number of samples queued in the audio device. More...
guint64	get_samples_done () const
	Get the number of samples that were processed by the ringbuffer since it was last started. More...
void	set_sample (guint64 sample)
	Make sure that the next sample written to the device is accounted for as being the sample sample written to the device. More...
void	set_channel_position (const Gst::AudioChannelPosition& position)
	Tell the ringbuffer about the device's channel positions. More...
gboolean	is_flushing ()
	Check if buf is flushing. More...
void	set_timestamp (gint readseg, ClockTime timestamp)
guint	commit (guint64& sample, const std::vector< guint8 >& data, int in_samples, int out_samples, int& accum)
	Commit in_samples samples pointed to by data to the ringbuffer buf. More...
bool	convert (Gst::Format src_fmt, gint64 src_val, Gst::Format dest_fmt, gint64& dest_val) const
	Convert src_val in src_fmt to the equivalent value in dest_fmt. More...
bool	prepare_read (int& segment, std::vector< guint8 >& readptr, int& len)
	Returns a pointer to memory where the data from segment segment can be found. More...
guint	read (guint64 sample, const std::vector< guint8 >& data, guint len, ClockTime& timestamp)
	Read len samples from the ringbuffer into the memory pointed to by data. More...
void	clear (int segment)
	Clear the given segment of the buffer with silence samples. More...
void	clear_all ()
	Fill the ringbuffer with silence. More...
void	advance (guint advance)
	Subclasses should call this function to notify the fact that advance segments are now processed by the device. More...
bool	close_device ()
	Close the audio device associated with the ring buffer. More...
bool	open_device ()
	Open the audio device associated with the ring buffer. More...
bool	device_is_open () const
	Checks the status of the device associated with the ring buffer. More...
void	set_may_start (bool allowed)
	Tell the ringbuffer that it is allowed to start playback when the ringbuffer is filled with samples. More...
void	set_flushing (bool flushing)
	Set the ringbuffer to flushing mode or normal mode. More...
virtual bool	open_device_vfunc ()
	Virtual function to open the device. More...
virtual bool	acquire_vfunc (Gst::AudioRingBufferSpec& spec)
	Virtual function to allocate the resources for the ring buffer using the given spec. More...
virtual bool	release_vfunc ()
	Virtual function to free resources of the ring buffer. More...
virtual bool	close_device_vfunc ()
	Virtual function to close the device. More...
virtual bool	start_vfunc ()
	Virtual function to start processing of samples. More...
virtual bool	pause_vfunc ()
	Virtual function to pause processing of samples. More...
virtual bool	resume_vfunc ()
	Virtual function to resume processing of samples after pause. More...
virtual bool	stop_vfunc ()
	Virtual function to stop processing of samples. More...
virtual guint	delay_vfunc ()
	Virtual function to get number of samples queued in device. More...
virtual bool	activate_vfunc (bool active)
	Virtual function to activate the thread that starts pulling and monitoring the consumed segments in the device. More...
virtual guint	commit_vfunc (guint64& sample, const std::vector< guint8 >& data, int in_samples, int out_samples, int& accum)
	Virtual function to write samples into the ring buffer. More...
virtual void	clear_all_vfunc ()
	Virtual function to clear the entire audioringbuffer Since 0.10.24. More...
Public Member Functions inherited from Gst::Object
virtual	~Object ()
GstObject*	gobj ()
	Provides access to the underlying C GObject. More...
const GstObject*	gobj () const
	Provides access to the underlying C GObject. More...
GstObject*	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
bool	is_element () const
bool	is_element_factory () const
bool	is_pad () const
bool	is_pad_template () const
bool	is_bin () const
guint32	get_flags () const
	Returns the entire set of flags for the object. More...
bool	set_name (const Glib::ustring& name)
	Sets the name of object, or gives object a guaranteed unique name (if name is 0). More...
Glib::ustring	get_name () const
	Returns a copy of the name of object. More...
bool	set_parent (const Glib::RefPtr< Gst::Object >& parent)
	Sets the parent of object to parent. More...
Glib::RefPtr< Gst::Object >	get_parent ()
	Returns the parent of object. More...
Glib::RefPtr< const Gst::Object >	get_parent () const
	Returns the parent of object. More...
void	unparent ()
	Clear the parent of object, removing the associated reference. More...
bool	has_ancestor (const Glib::RefPtr< const Gst::Object >& ancestor) const
	Check if object has an ancestor ancestor somewhere up in the hierarchy. More...
Glib::ustring	get_path_string ()
	Generates a string describing the path of object in the object hierarchy. More...
Glib::PropertyProxy < Glib::ustring >	property_name ()
	The name of the object. More...
Glib::PropertyProxy_ReadOnly < Glib::ustring >	property_name () const
	The name of the object. More...
Glib::SignalProxy2< void, const Glib::RefPtr< Object > &, GParamSpec* >	signal_deep_notify ()
int	get_refcount () const

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system. More...
static bool	parse_caps (Gst::AudioRingBufferSpec& p1, const Glib::RefPtr< Gst::Caps >& caps)
	Parse caps into spec. More...
Static Public Member Functions inherited from Gst::Object
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system. More...
static bool	check_uniqueness (const Glib::ListHandle< const Gst::Object >& list, const Glib::ustring& name)
	Checks to see if there is any object named name in list. More...

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

Additional Inherited Members
Protected Member Functions inherited from Gst::Object
virtual void	on_deep_notify (const Glib::RefPtr< Object >& prop_object, GParamSpec* prop)
	This is a default handler for the signal signal_deep_notify(). More...

Detailed Description

A base class for audio audioringbuffer implementations.

This object is the base class for audio ringbuffers used by the base audio source and sink classes.

The audioringbuffer abstracts a circular buffer of data. One reader and one writer can operate on the data from different threads in a lockfree manner. The base class is sufficiently flexible to be used as an abstraction for DMA based audioringbuffer as well as a pure software implementations.

Last reviewed on 2006-02-02 (0.10.4).

Member Typedef Documentation

typedef sigc::slot<void, const Glib::ArrayHandle<guint8>&, guint> Gst::AudioRingBuffer::SlotFill

For example, bool on_fill(const Glib::RefPtr<Gst::AudioRingBuffer>& rbuf, const std::vector<guint8>& data, guint len);.

This slot is set with set_fill_slot() and is called to fill the memory at data with len bytes of samples.

Constructor & Destructor Documentation

virtual Gst::AudioRingBuffer::~AudioRingBuffer ( )

virtual

Member Function Documentation

bool Gst::AudioRingBuffer::acquire

(

Gst::AudioRingBufferSpec&

spec

)

Allocate the resources for the ringbuffer.

This function fills in the data pointer of the ring buffer with a valid Gst::Buffer to which samples can be written.

Parameters

spec	The specs of the buffer.

Returns

true if the device could be acquired, false on error.

MT safe.

virtual bool Gst::AudioRingBuffer::acquire_vfunc ( Gst::AudioRingBufferSpec&  spec )

virtual

Virtual function to allocate the resources for the ring buffer using the given spec.

bool Gst::AudioRingBuffer::activate

(

bool

active

)

Activate buf to start or stop pulling data.

MT safe.

Parameters

active

The new mode.

Returns

true if the device could be activated in the requested mode, false on error.

virtual bool Gst::AudioRingBuffer::activate_vfunc ( bool  active )

virtual

Virtual function to activate the thread that starts pulling and monitoring the consumed segments in the device.

Since 0.10.22.

void Gst::AudioRingBuffer::advance

(

guint

advance

)

Subclasses should call this function to notify the fact that advance segments are now processed by the device.

MT safe.

Parameters

advance

The number of segments written.

void Gst::AudioRingBuffer::clear

(

int

segment

)

Clear the given segment of the buffer with silence samples.

This function is used by subclasses.

MT safe.

Parameters

segment

The segment to clear.

void Gst::AudioRingBuffer::clear_all

(

)

Fill the ringbuffer with silence.

MT safe.

virtual void Gst::AudioRingBuffer::clear_all_vfunc ( )

virtual

Virtual function to clear the entire audioringbuffer Since 0.10.24.

bool Gst::AudioRingBuffer::close_device

(

)

Close the audio device associated with the ring buffer.

The ring buffer should already have been released via release().

Returns

true if the device could be closed, false on error.

MT safe.

virtual bool Gst::AudioRingBuffer::close_device_vfunc ( )

virtual

Virtual function to close the device.

guint Gst::AudioRingBuffer::commit	(	guint64 &	sample,
		const std::vector< guint8 > &	data,
		int	in_samples,
		int	out_samples,
		int &	accum
	)

Commit in_samples samples pointed to by data to the ringbuffer buf.

in_samples and out_samples define the rate conversion to perform on the samples in data. For negative rates, out_samples must be negative and in_samples positive.

When out_samples is positive, the first sample will be written at position sample in the ringbuffer. When out_samples is negative, the last sample will be written to sample in reverse order.

out_samples does not need to be a multiple of the segment size of the ringbuffer although it is recommended for optimal performance.

accum will hold a temporary accumulator used in rate conversion and should be set to 0 when this function is first called. In case the commit operation is interrupted, one can resume the processing by passing the previously returned accum value back to this function.

MT safe.

Parameters

sample	The sample position of the data.
data	The data to commit.
in_samples	The number of samples in the data to commit.
out_samples	The number of samples to write to the ringbuffer.
accum	Accumulator for rate conversion.

Returns

The number of samples written to the ringbuffer or -1 on error. The number of samples written can be less than out_samples when buf was interrupted with a flush or stop.

virtual guint Gst::AudioRingBuffer::commit_vfunc ( guint64 &  sample, const std::vector< guint8 > &  data, int  in_samples, int  out_samples, int &  accum  )

virtual

Virtual function to write samples into the ring buffer.

bool Gst::AudioRingBuffer::convert	(	Gst::Format	src_fmt,
		gint64	src_val,
		Gst::Format	dest_fmt,
		gint64 &	dest_val
	)		const

Convert src_val in src_fmt to the equivalent value in dest_fmt.

The result will be put in dest_val.

Parameters

src_fmt	The source format.
src_val	The source value.
dest_fmt	The destination format.
dest_val	A location to store the converted value.

Returns

true if the conversion succeeded.

virtual guint Gst::AudioRingBuffer::delay_vfunc ( )

virtual

Virtual function to get number of samples queued in device.

bool Gst::AudioRingBuffer::device_is_open

(

)

const

Checks the status of the device associated with the ring buffer.

Returns

true if the device was open, false if it was closed.

MT safe.

guint Gst::AudioRingBuffer::get_delay

(

)

const

Get the number of samples queued in the audio device.

This is usually less than the segment size but can be bigger when the implementation uses another internal buffer between the audio device.

For playback ringbuffers this is the amount of samples transfered from the ringbuffer to the device but still not played.

For capture ringbuffers this is the amount of samples in the device that are not yet transfered to the ringbuffer.

Returns

The number of samples queued in the audio device.

MT safe.

guint64 Gst::AudioRingBuffer::get_samples_done

(

)

const

Get the number of samples that were processed by the ringbuffer since it was last started.

This does not include the number of samples not yet processed (see delay()).

Returns

The number of samples processed by the ringbuffer.

MT safe.

static GType Gst::AudioRingBuffer::get_type ( )

static

Get the GType for this class, for use with the underlying GObject type system.

GstAudioRingBuffer* Gst::AudioRingBuffer::gobj ( )

inline

Provides access to the underlying C GObject.

const GstAudioRingBuffer* Gst::AudioRingBuffer::gobj ( ) const

inline

Provides access to the underlying C GObject.

GstAudioRingBuffer* Gst::AudioRingBuffer::gobj_copy

(

)

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

bool Gst::AudioRingBuffer::is_acquired

(

)

const

Check if the ringbuffer is acquired and ready to use.

Returns

true if the ringbuffer is acquired, false on error.

MT safe.

bool Gst::AudioRingBuffer::is_active

(

)

const

Check if buf is activated.

MT safe.

Returns

true if the device is active.

gboolean Gst::AudioRingBuffer::is_flushing

(

)

Check if buf is flushing.

MT safe.

Returns

true if the device is flushing.

bool Gst::AudioRingBuffer::open_device

(

)

Open the audio device associated with the ring buffer.

Does not perform any setup on the device. You must open the device before acquiring the ring buffer.

Returns

true if the device could be opened, false on error.

MT safe.

virtual bool Gst::AudioRingBuffer::open_device_vfunc ( )

virtual

Virtual function to open the device.

Don't set any params or allocate anything.

static bool Gst::AudioRingBuffer::parse_caps ( Gst::AudioRingBufferSpec&  p1, const Glib::RefPtr< Gst::Caps >&  caps  )

static

Parse caps into spec.

Parameters

spec	A spec.
caps	A Gst::Caps.

Returns

true if the caps could be parsed.

bool Gst::AudioRingBuffer::pause

(

)

Pause processing samples from the ringbuffer.

Returns

true if the device could be paused, false on error.

MT safe.

virtual bool Gst::AudioRingBuffer::pause_vfunc ( )

virtual

Virtual function to pause processing of samples.

bool Gst::AudioRingBuffer::prepare_read	(	int &	segment,
		std::vector< guint8 > &	readptr,
		int &	len
	)

Returns a pointer to memory where the data from segment segment can be found.

This function is mostly used by subclasses.

Parameters

segment	The segment to read.
readptr	The pointer to the memory where samples can be read.
len	The number of bytes to read.

Returns

false if the buffer is not started.

MT safe.

guint Gst::AudioRingBuffer::read	(	guint64	sample,
		const std::vector< guint8 > &	data,
		guint	len,
		ClockTime&	timestamp
	)

Read len samples from the ringbuffer into the memory pointed to by data.

The first sample should be read from position sample in the ringbuffer.

len should not be a multiple of the segment size of the ringbuffer although it is recommended.

timestamp will return the timestamp associated with the data returned.

Parameters

sample	The sample position of the data.
data	Where the data should be read.
len	The number of samples in data to read.
timestamp	Where the timestamp is returned.

Returns

The number of samples read from the ringbuffer or -1 on error.

MT safe.

bool Gst::AudioRingBuffer::release

(

)

Free the resources of the ringbuffer.

Returns

true if the device could be released, false on error.

MT safe.

virtual bool Gst::AudioRingBuffer::release_vfunc ( )

virtual

Virtual function to free resources of the ring buffer.

virtual bool Gst::AudioRingBuffer::resume_vfunc ( )

virtual

Virtual function to resume processing of samples after pause.

void Gst::AudioRingBuffer::set_channel_position

(

const Gst::AudioChannelPosition&

position

)

Tell the ringbuffer about the device's channel positions.

This must be called in when the ringbuffer is acquired.

Parameters

position

The device channel positions.

void Gst::AudioRingBuffer::set_fill_slot

(

const SlotFill&

slot

)

Sets the given fill slot on the buffer.

The slot will be called every time a segment has been written to a device.

MT safe.

Parameters

slot	The fill slot to set.

void Gst::AudioRingBuffer::set_flushing

(

bool

flushing

)

Set the ringbuffer to flushing mode or normal mode.

MT safe.

Parameters

flushing

The new mode.

void Gst::AudioRingBuffer::set_may_start

(

bool

allowed

)

Tell the ringbuffer that it is allowed to start playback when the ringbuffer is filled with samples.

MT safe.

Parameters

allowed

The new value.

void Gst::AudioRingBuffer::set_sample

(

guint64

sample

)

Make sure that the next sample written to the device is accounted for as being the sample sample written to the device.

This value will be used in reporting the current sample position of the ringbuffer.

This function will also clear the buffer with silence.

MT safe.

Parameters

sample

The sample number to set.

void Gst::AudioRingBuffer::set_timestamp	(	gint	readseg,
		ClockTime	timestamp
	)

bool Gst::AudioRingBuffer::start

(

)

Start processing samples from the ringbuffer.

Returns

true if the device could be started, false on error.

MT safe.

virtual bool Gst::AudioRingBuffer::start_vfunc ( )

virtual

Virtual function to start processing of samples.

bool Gst::AudioRingBuffer::stop

(

)

Stop processing samples from the ringbuffer.

Returns

true if the device could be stopped, false on error.

MT safe.

virtual bool Gst::AudioRingBuffer::stop_vfunc ( )

virtual

Virtual function to stop processing of samples.

Friends And Related Function Documentation

Glib::RefPtr< Gst::AudioRingBuffer > wrap ( GstAudioRingBuffer *  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/audioringbuffer.h