gstreamermm
1.0.10
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A class that describes sets of media formats. More...
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... | |
GstCaps* | gobj () |
Provides access to the underlying C instance. More... | |
const GstCaps* | gobj () const |
Provides access to the underlying C instance. More... | |
GstCaps* | 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::Caps > | copy () const |
Glib::RefPtr< Gst::Caps > | copy_nth (guint nth) const |
Creates a new Gst::Caps and appends a copy of the nth structure contained in caps. More... | |
void | append (const Glib::RefPtr< Gst::Caps >& caps) |
Appends the structures contained in caps2 to caps1. More... | |
Glib::RefPtr< Gst::Caps > | merge (const Glib::RefPtr< Gst::Caps >& caps) |
Appends the structures contained in caps2 to caps1 if they are not yet expressed by caps1. More... | |
void | append_structure (const Structure& structure) |
Appends a structure to caps. More... | |
Glib::RefPtr< Gst::Caps > | merge_structure (Structure& structure) |
Appends a structure to caps if its not already expressed by caps. More... | |
const Structure | get_structure (guint idx) const |
Finds the structure in caps that has the index idx, and returns it. More... | |
void | remove_structure (guint idx) |
removes the stucture with the given index from the list of structures contained in caps. More... | |
guint | size () const |
Gets the number of structures contained in caps. More... | |
Structure | steal_structure (guint index) |
Retrieves the structure with the given index from the list of structures contained in caps. More... | |
void | set_simple (const Glib::ustring& name, const Glib::ValueBase& value) |
Sets fields in a simple Gst::Caps. More... | |
template<class DataType > | |
void | set_simple (const Glib::ustring& name, const DataType& data) |
Sets fields in a simple Gst::Caps. More... | |
void | set_simple (const Glib::ustring& name, const char* data) |
Sets fields in a simple Gst::Caps. More... | |
void | set_value (const Glib::ustring& field, const Glib::ValueBase& value) |
Sets the given field on all structures of caps to the given value. More... | |
template<class DataType > | |
void | set_value (const Glib::ustring& name, const DataType& data) |
Sets the given field on all structures to the given value. More... | |
bool | is_any () const |
Determines if caps represents any media format. More... | |
bool | empty () const |
Determines if caps represents no media formats. More... | |
bool | is_fixed () const |
Fixed Gst::Caps describe exactly one format, that is, they have exactly one structure, and each field in the structure describes a fixed type. More... | |
bool | equals (const Glib::RefPtr< const Gst::Caps >& other_caps) const |
Checks if the given caps represent the same set of caps. More... | |
bool | equals_fixed (const Glib::RefPtr< const Gst::Caps >& other_caps) const |
Tests if two Gst::Caps are equal. More... | |
bool | is_always_compatible (const Glib::RefPtr< const Gst::Caps >& other_caps) const |
A given Gst::Caps structure is always compatible with another if every media format that is in the first is also contained in the second. More... | |
bool | is_subset (const Glib::RefPtr< const Gst::Caps >& superset_caps) const |
Checks if all caps represented by subset are also represented by superset. More... | |
bool | can_intersect (const Glib::RefPtr< const Gst::Caps >& caps2) const |
Tries intersecting caps1 and caps2 and reports whether the result would not be empty. More... | |
Glib::RefPtr< Gst::Caps > | get_intersect (const Glib::RefPtr< const Gst::Caps >& other_caps) const |
Creates a new Gst::Caps that contains all the formats that are common to both caps1 and caps2. More... | |
Glib::RefPtr< Gst::Caps > | get_intersect (const Glib::RefPtr< const Gst::Caps >& other_caps, CapsIntersectMode p2) const |
Creates a new Gst::Caps that contains all the formats that are common to both caps1 and caps2, the order is defined by the Gst::CapsIntersectMode used. More... | |
Glib::RefPtr< Gst::Caps > | get_normal () const |
Returns a Gst::Caps that represents the same set of formats as caps, but contains no lists. More... | |
Glib::RefPtr< Gst::Caps > | simplify () |
Converts the given caps into a representation that represents the same set of formats, but in a simpler form. More... | |
Glib::ustring | to_string () const |
Converts caps to a string representation. More... | |
Glib::RefPtr< Gst::Caps > | get_difference (const Glib::RefPtr< const Gst::Caps >& subtrahend_caps) const |
Subtracts the subtrahend from the minuend. More... | |
Glib::RefPtr< Gst::Caps > | create_writable () |
Glib::RefPtr< Gst::Caps > | truncate () |
Discard all but the first structure from caps. More... | |
Static Public Member Functions | |
static Glib::RefPtr< Caps > | create () |
static Glib::RefPtr< Gst::Caps > | create_any () |
Creates a new Gst::Caps that indicates that it is compatible with any media format. More... | |
static Glib::RefPtr< Gst::Caps > | create_simple (const Glib::ustring& media_type) |
Creates a new Gst::Caps that contains one Gst::Structure. More... | |
static Glib::RefPtr< Gst::Caps > | create (const Structure& first_struct) |
Creates a new Gst::Caps and adds the given Gst::Structure. More... | |
static Glib::RefPtr< Gst::Caps > | create_from_string (const Glib::ustring&string) |
Converts caps from a string representation. More... | |
Protected Member Functions | |
Caps () | |
void | operator delete (void*, std::size_t) |
Related Functions | |
(Note that these are not member functions.) | |
Glib::RefPtr< Gst::Caps > | wrap (GstCaps* object, bool take_copy=false) |
A Glib::wrap() method for this object. More... | |
A class that describes sets of media formats.
Caps (capabilities) are lightweight objects describing media formats. They are composed of an array of Gst::Structure.
Caps are exposed on Gst::PadTemplate to describe all possible types a given pad can handle. They are also stored in the Gst::Registry along with a description of the Gst::Element.
Caps are exposed on the element pads using the Gst::Pad::get_caps() method. This method describes the possible types that the pad can handle or produce at runtime.
Caps are also attached to buffers to describe to content of the data pointed to by the buffer with Gst::Buffer::set_caps(). Gst::Caps attached to a Gst::Buffer allow for format negotiation upstream and downstream.
A Gst::Caps can be constructed with the following code fragment:
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protected |
void Gst::Caps::append | ( | const Glib::RefPtr< Gst::Caps >& | caps | ) |
Appends the structures contained in caps2 to caps1.
The structures in caps2 are not copied – they are transferred to caps1, and then caps2 is freed. If either caps is ANY, the resulting caps will be ANY.
caps2 | The Gst::Caps to append. |
void Gst::Caps::append_structure | ( | const Structure& | structure | ) |
Appends a structure to caps.
structure | The Gst::Structure to append. |
bool Gst::Caps::can_intersect | ( | const Glib::RefPtr< const Gst::Caps >& | caps2 | ) | const |
Tries intersecting caps1 and caps2 and reports whether the result would not be empty.
caps2 | A Gst::Caps to intersect. |
true
if intersection would be not empty. Glib::RefPtr<Gst::Caps> Gst::Caps::copy | ( | ) | const |
Glib::RefPtr<Gst::Caps> Gst::Caps::copy_nth | ( | guint | nth | ) | const |
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Creates a new Gst::Caps and adds the given Gst::Structure.
Use append_structure() to add additional structures.
first_struct | The first structure to add. |
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Creates a new Gst::Caps that contains one Gst::Structure.
media_type | The media type of the structure. |
Glib::RefPtr<Gst::Caps> Gst::Caps::create_writable | ( | ) |
bool Gst::Caps::empty | ( | ) | const |
Determines if caps represents no media formats.
true
if caps represents no formats. bool Gst::Caps::equals | ( | const Glib::RefPtr< const Gst::Caps >& | other_caps | ) | const |
Checks if the given caps represent the same set of caps.
caps2 | Another Gst::Caps. |
true
if both caps are equal. bool Gst::Caps::equals_fixed | ( | const Glib::RefPtr< const Gst::Caps >& | other_caps | ) | const |
Glib::RefPtr<Gst::Caps> Gst::Caps::get_difference | ( | const Glib::RefPtr< const Gst::Caps >& | subtrahend_caps | ) | const |
Subtracts the subtrahend from the minuend.
<note>This function does not work reliably if optional properties for caps are included on one caps and omitted on the other.</note>
subtrahend | Gst::Caps to subtract. |
Glib::RefPtr<Gst::Caps> Gst::Caps::get_intersect | ( | const Glib::RefPtr< const Gst::Caps >& | other_caps | ) | const |
Creates a new Gst::Caps that contains all the formats that are common to both caps1 and caps2.
Defaults to Gst::CAPS_INTERSECT_ZIG_ZAG mode.
caps2 | A Gst::Caps to intersect. |
Glib::RefPtr<Gst::Caps> Gst::Caps::get_intersect | ( | const Glib::RefPtr< const Gst::Caps >& | other_caps, |
CapsIntersectMode | p2 | ||
) | const |
Creates a new Gst::Caps that contains all the formats that are common to both caps1 and caps2, the order is defined by the Gst::CapsIntersectMode used.
caps2 | A Gst::Caps to intersect. |
mode | The intersection algorithm/mode to use. |
Glib::RefPtr<Gst::Caps> Gst::Caps::get_normal | ( | ) | const |
const Structure Gst::Caps::get_structure | ( | guint | idx | ) | const |
Finds the structure in caps that has the index idx, and returns it.
index | The index of the structure. |
GstCaps* Gst::Caps::gobj | ( | ) |
Provides access to the underlying C instance.
const GstCaps* Gst::Caps::gobj | ( | ) | const |
Provides access to the underlying C instance.
GstCaps* Gst::Caps::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::Caps::is_always_compatible | ( | const Glib::RefPtr< const Gst::Caps >& | other_caps | ) | const |
bool Gst::Caps::is_any | ( | ) | const |
Determines if caps represents any media format.
true
if caps represents any format. bool Gst::Caps::is_fixed | ( | ) | const |
Fixed Gst::Caps describe exactly one format, that is, they have exactly one structure, and each field in the structure describes a fixed type.
Examples of non-fixed types are GST_TYPE_INT_RANGE and GST_TYPE_LIST.
true
if caps is fixed. bool Gst::Caps::is_subset | ( | const Glib::RefPtr< const Gst::Caps >& | superset_caps | ) | const |
Checks if all caps represented by subset are also represented by superset.
superset | A potentially greater Gst::Caps. |
true
if subset is a subset of superset. Appends the structures contained in caps2 to caps1 if they are not yet expressed by caps1.
The structures in caps2 are not copied – they are transferred to a writable copy of caps1, and then caps2 is freed. If either caps is ANY, the resulting caps will be ANY.
caps2 | The Gst::Caps to merge in. |
Appends a structure to caps if its not already expressed by caps.
structure | The Gst::Structure to merge. |
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protected |
void Gst::Caps::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::Caps::remove_structure | ( | guint | idx | ) |
removes the stucture with the given index from the list of structures contained in caps.
idx | Index of the structure to remove. |
void Gst::Caps::set_simple | ( | const Glib::ustring & | name, |
const Glib::ValueBase & | value | ||
) |
Sets fields in a simple Gst::Caps.
A simple Gst::Caps is one that only has one structure. This method, like the Gst::Structure::set_field() methods, translates certain GTypes to GStreamer specific GTypes for functional compatibility.
name | Field to set. |
value | The value which the field should be set to. |
void Gst::Caps::set_simple | ( | const Glib::ustring & | name, |
const DataType & | data | ||
) |
Sets fields in a simple Gst::Caps.
A simple Gst::Caps is one that only has one structure. This method, like the Gst::Structure::set_field() methods, translates certain GTypes to GStreamer specific GTypes for functional compatibility.
name | Field to set. |
data | A value which the field should be set to (this can be any supported C++ type). |
void Gst::Caps::set_simple | ( | const Glib::ustring & | name, |
const char * | data | ||
) |
void Gst::Caps::set_value | ( | const Glib::ustring & | field, |
const Glib::ValueBase & | value | ||
) |
Sets the given field on all structures of caps to the given value.
This is a convenience function for calling Gst::Structure::set_value() on all structures of caps.
field | Name of the field to set. |
value | Value to set the field to. |
void Gst::Caps::set_value | ( | const Glib::ustring & | name, |
const DataType & | data | ||
) |
Sets the given field on all structures to the given value.
This is a convenience function for calling Gst::Structure::set_value() on all structures.
name | Field to set. |
data | A value which the field should be set to (this can be any supported C++ type). |
Glib::RefPtr<Gst::Caps> Gst::Caps::simplify | ( | ) |
Converts the given caps into a representation that represents the same set of formats, but in a simpler form.
Component structures that are identical are merged. Component structures that have values that can be merged are also merged.
This method does not preserve the original order of caps.
guint Gst::Caps::size | ( | ) | const |
Gets the number of structures contained in caps.
Structure Gst::Caps::steal_structure | ( | guint | index | ) |
Retrieves the structure with the given index from the list of structures contained in caps.
The caller becomes the owner of the returned structure.
index | Index of the structure to retrieve. |
Glib::ustring Gst::Caps::to_string | ( | ) | const |
Converts caps to a string representation.
This string representation can be converted back to a Gst::Caps by from_string().
For debugging purposes its easier to do something like this:
[C example ellipted] This prints the caps in human readable form.
Glib::RefPtr<Gst::Caps> Gst::Caps::truncate | ( | ) |
Discard all but the first structure from caps.
Useful when fixating.
void Gst::Caps::unreference | ( | ) | const |
Decrement the reference count for this object.
You should never need to do this manually - use the object via a RefPtr instead.
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related |
A Glib::wrap() method for this object.
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. |