Public Member Functions | Static Public Attributes | Related Functions

Gst::BaseTransform Class Reference
[gstreamermm Base Classes]

A base class for simple transform filters. More...

Inherits Gst::Element.

Inherited by Gst::AudioConvert, Gst::AudioFilter, Gst::AudioResample, Gst::CapsFilter, Gst::FfmpegColorSpace, Gst::Identity, and Gst::VideoScale.

Collaboration diagram for Gst::BaseTransform:
Collaboration graph
[legend]

List of all members.

Public Member Functions

virtual ~BaseTransform ()
GstBaseTransform* gobj ()
 Provides access to the underlying C GObject.
const GstBaseTransform* gobj () const
 Provides access to the underlying C GObject.
GstBaseTransform* gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
bool is_passthrough () const
 See if trans is configured as a passthrough transform.
void set_passthrough (bool passthrough)
 Set passthrough mode for this filter by default.
bool is_in_place () const
 See if trans is configured as a in_place transform.
void set_in_place (bool in_place)
 Determines whether a non-writable buffer will be copied before passing to the transform_ip function.
bool is_qos_enabled () const
 Queries if the transform will handle QoS.
void set_qos_enabled (bool enabled)
 Enable or disable QoS handling in the transform.
void update_qos (double proportion, ClockTimeDiff diff, ClockTime timestamp)
 Set the QoS parameters in the transform.
void set_gap_aware (bool gap_aware)
 If gap_aware is false (the default), output buffers will have the Gst::BUFFER_FLAG_GAP flag unset.
void suggest (const Glib::RefPtr< Gst::Caps >& caps, guint size)
 Instructs trans to suggest new caps upstream.
void reconfigure ()
 Instructs trans to renegotiate a new downstream transform on the next buffer.
void lock ()
 Obtain a lock to protect the transform function from concurrent access.
void unlock ()
 Release the lock that protects the transform function from concurrent access.
Glib::RefPtr< Gst::Padget_sink_pad ()
 Gives the refptr to the sink Gst::Pad object of the element.
Glib::RefPtr< const Gst::Padget_sink_pad () const
Glib::RefPtr< Gst::Padget_src_pad ()
 Gives the refptr to the source Gst::Pad object of the element.
Glib::RefPtr< const Gst::Padget_src_pad () const
Glib::PropertyProxy< bool > property_qos ()
 Handle Quality-of-Service events.
Glib::PropertyProxy_ReadOnly
< bool > 
property_qos () const
 Handle Quality-of-Service events.
virtual Glib::RefPtr< Gst::Capstransform_caps_vfunc (PadDirection direction, const Glib::RefPtr< Gst::Caps >& caps)
 Optional.
virtual void fixate_caps_vfunc (PadDirection direction, const Glib::RefPtr< Gst::Caps >& caps, const Glib::RefPtr< Gst::Caps >& othercaps)
 Optional.
virtual FlowReturn transform_vfunc (const Glib::RefPtr< Gst::Buffer >& inbuf, const Glib::RefPtr< Gst::Buffer >& outbuf)
 Optional.
virtual FlowReturn transform_ip_vfunc (const Glib::RefPtr< Gst::Buffer >& buf)
 Required if the element operates in-place.
virtual FlowReturn prepare_output_buffer_vfunc (const Glib::RefPtr< Gst::Buffer >& input, int size, const Glib::RefPtr< Gst::Caps >& caps, Glib::RefPtr< Gst::Buffer >& buffer)
 Optional.
virtual void before_transform_vfunc (const Glib::RefPtr< Gst::Buffer >& buffer)
 Optional.

Static Public Attributes

static const Glib::ustring SINK_NAME
 The name of the templates for the sink pad ("sink").
static const Glib::ustring SRC_NAME
 The name of the templates for the source pad ("src").

Related Functions

(Note that these are not member functions.)



Glib::RefPtr< Gst::BaseTransformwrap (GstBaseTransform* object, bool take_copy=false)
 A Glib::wrap() method for this object.

Detailed Description

A base class for simple transform filters.

This base class is for filter elements that process data.

It provides for:

Use Cases:

Sub-class settable flags on Gst::BaseTransform


Constructor & Destructor Documentation

virtual Gst::BaseTransform::~BaseTransform (  )  [virtual]

Member Function Documentation

virtual void Gst::BaseTransform::before_transform_vfunc ( const Glib::RefPtr< Gst::Buffer >&  buffer  )  [virtual]

Optional.

Event handler on the source pad. Optional. Since 0.10.22 This method is called right before the base class will start processing. Dynamic properties or other delayed configuration could be performed in this method.

virtual void Gst::BaseTransform::fixate_caps_vfunc ( PadDirection  direction,
const Glib::RefPtr< Gst::Caps >&  caps,
const Glib::RefPtr< Gst::Caps >&  othercaps 
) [virtual]

Optional.

Given the pad in this direction and the given caps, fixate the caps on the other pad.

Glib::RefPtr<Gst::Pad> Gst::BaseTransform::get_sink_pad (  ) 

Gives the refptr to the sink Gst::Pad object of the element.

Glib::RefPtr<const Gst::Pad> Gst::BaseTransform::get_sink_pad (  )  const
Glib::RefPtr<Gst::Pad> Gst::BaseTransform::get_src_pad (  ) 

Gives the refptr to the source Gst::Pad object of the element.

Glib::RefPtr<const Gst::Pad> Gst::BaseTransform::get_src_pad (  )  const
const GstBaseTransform* Gst::BaseTransform::gobj (  )  const [inline]

Provides access to the underlying C GObject.

Reimplemented from Gst::Element.

Reimplemented in Gst::AudioFilter, Gst::AudioConvert, Gst::AudioResample, Gst::CapsFilter, Gst::FfmpegColorSpace, Gst::Identity, and Gst::VideoScale.

GstBaseTransform* Gst::BaseTransform::gobj (  )  [inline]

Provides access to the underlying C GObject.

Reimplemented from Gst::Element.

Reimplemented in Gst::AudioFilter, Gst::AudioConvert, Gst::AudioResample, Gst::CapsFilter, Gst::FfmpegColorSpace, Gst::Identity, and Gst::VideoScale.

GstBaseTransform* Gst::BaseTransform::gobj_copy (  ) 

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

Reimplemented from Gst::Element.

Reimplemented in Gst::AudioFilter, Gst::AudioConvert, Gst::AudioResample, Gst::CapsFilter, Gst::FfmpegColorSpace, Gst::Identity, and Gst::VideoScale.

bool Gst::BaseTransform::is_in_place (  )  const

See if trans is configured as a in_place transform.

Returns:
true is the transform is configured in in_place mode.

MT safe.

bool Gst::BaseTransform::is_passthrough (  )  const

See if trans is configured as a passthrough transform.

Returns:
true is the transform is configured in passthrough mode.

MT safe.

bool Gst::BaseTransform::is_qos_enabled (  )  const

Queries if the transform will handle QoS.

Since gstreamermm 0.10:
.5
Returns:
true if QoS is enabled.

MT safe.

void Gst::BaseTransform::lock (  ) 

Obtain a lock to protect the transform function from concurrent access.

virtual FlowReturn Gst::BaseTransform::prepare_output_buffer_vfunc ( const Glib::RefPtr< Gst::Buffer >&  input,
int  size,
const Glib::RefPtr< Gst::Caps >&  caps,
Glib::RefPtr< Gst::Buffer >&  buffer 
) [virtual]

Optional.

Subclasses can override this to do their own allocation of output buffers. Elements that only do analysis can return a subbuffer or even just increment the reference to the input buffer (if in passthrough mode).

Glib::PropertyProxy_ReadOnly<bool> Gst::BaseTransform::property_qos (  )  const

Handle Quality-of-Service events.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns:
A PropertyProxy that allows you to get or set the property of the value, or receive notification when the value of the property changes.
Glib::PropertyProxy<bool> Gst::BaseTransform::property_qos (  ) 

Handle Quality-of-Service events.

You rarely need to use properties because there are get_ and set_ methods for almost all of them.

Returns:
A PropertyProxy that allows you to get or set the property of the value, or receive notification when the value of the property changes.
void Gst::BaseTransform::reconfigure (  ) 

Instructs trans to renegotiate a new downstream transform on the next buffer.

This function is typically called after properties on the transform were set that influence the output format.

Since gstreamermm 0.10:
.21
void Gst::BaseTransform::set_gap_aware ( bool  gap_aware  ) 

If gap_aware is false (the default), output buffers will have the Gst::BUFFER_FLAG_GAP flag unset.

If set to true, the element must handle output buffers with this flag set correctly, i.e. it can assume that the buffer contains neutral data but must unset the flag if the output is no neutral data.

MT safe.

Since gstreamermm 0.10:
.16
Parameters:
gap_aware New state.
void Gst::BaseTransform::set_in_place ( bool  in_place  ) 

Determines whether a non-writable buffer will be copied before passing to the transform_ip function.

<itemizedlist> <listitem>Always true if no transform function is implemented.</listitem> <listitem>Always false if ONLY transform function is implemented.</listitem> </itemizedlist>

MT safe.

Parameters:
in_place Boolean value indicating that we would like to operate on in_place buffers.
void Gst::BaseTransform::set_passthrough ( bool  passthrough  ) 

Set passthrough mode for this filter by default.

This is mostly useful for filters that do not care about negotiation.

Always true for filters which don't implement either a transform or transform_ip method.

MT safe.

Parameters:
passthrough Boolean indicating passthrough mode.
void Gst::BaseTransform::set_qos_enabled ( bool  enabled  ) 

Enable or disable QoS handling in the transform.

MT safe.

Since gstreamermm 0.10:
.5
Parameters:
enabled New state.
void Gst::BaseTransform::suggest ( const Glib::RefPtr< Gst::Caps >&  caps,
guint  size 
)

Instructs trans to suggest new caps upstream.

A copy of caps will be taken.

Since gstreamermm 0.10:
.21
Parameters:
caps Caps to suggest.
size Buffer size to suggest.
virtual Glib::RefPtr<Gst::Caps> Gst::BaseTransform::transform_caps_vfunc ( PadDirection  direction,
const Glib::RefPtr< Gst::Caps >&  caps 
) [virtual]

Optional.

Given the pad in this direction and the given caps, what caps are allowed on the other pad in this element ?

virtual FlowReturn Gst::BaseTransform::transform_ip_vfunc ( const Glib::RefPtr< Gst::Buffer >&  buf  )  [virtual]

Required if the element operates in-place.

Transform the incoming buffer in-place.

virtual FlowReturn Gst::BaseTransform::transform_vfunc ( const Glib::RefPtr< Gst::Buffer >&  inbuf,
const Glib::RefPtr< Gst::Buffer >&  outbuf 
) [virtual]

Optional.

Given the size of a buffer in the given direction with the given caps, calculate the size in bytes of a buffer on the other pad with the given other caps. The default implementation uses get_unit_size_vfunc() and keeps the number of units the same. Required if the transform is not in-place. Get the size in bytes of one unit for the given caps. Allows the subclass to be notified of the actual caps set. Optional. Called when the element starts processing. Allows opening external resources. Optional. Called when the element stops processing. Allows closing external resources. Required if the element does not operate in-place. Transforms one incoming buffer to one outgoing buffer. The function is allowed to change size/timestamp/duration of the outgoing buffer.

void Gst::BaseTransform::unlock (  ) 

Release the lock that protects the transform function from concurrent access.

void Gst::BaseTransform::update_qos ( double  proportion,
ClockTimeDiff  diff,
ClockTime  timestamp 
)

Set the QoS parameters in the transform.

This function is called internally when a QOS event is received but subclasses can provide custom information when needed.

MT safe.

Since gstreamermm 0.10:
.5
Parameters:
proportion The proportion.
diff The diff against the clock.
timestamp The timestamp of the buffer generating the QoS expressed in running_time.

Friends And Related Function Documentation

Glib::RefPtr< Gst::BaseTransform > wrap ( GstBaseTransform *  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.

Member Data Documentation

The name of the templates for the sink pad ("sink").

The name of the templates for the source pad ("src").


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