Port Group
type: Class
subclass of: Restriction
  on property: symbol
  cardinality: 1
  comment: A pg:Group MUST have exactly one string lv2:symbol. This symbol must be unique according to the same rules as the lv2:symbol for an lv2:Port, where group symbols and port symbols reside in the same namespace. In other words, a group on a plugin MUST NOT have the same symbol as another group or a port on that plugin. This makes it possible to uniquely reference a port or group on a plugin with a single identifier and no context.
comment: A set of ports/channels/controls/etc that are are logically grouped together, e.g. two audio ports in a group may form a stereo stream. In order to avoid the need to define large numbers of identical group definitions, a group definition may be shared. For example, a plugin collection may define a single URI for a pg:StereoGroup with the symbol "input" and use it in many plugins.

Input Group
type: Class
subclass of: Port Group
comment: A group which contains exclusively inputs.

Output Group
type: Class
subclass of: Port Group
comment: A group which contains exclusively outputs.

Element
type: Class
comment: An ordered element of a group.
subclass of: Restriction
  on property: designation
  cardinality: 1
  comment: An element MUST have exactly one lv2:designation.
comment: An element of a group, which has a designation and an optional index.

element
type: Property
type: ObjectProperty
range: Element
comment: Indicates that a group has a certain element (a parameter or channel designation with a possible index).

side-chain of
type: Property
type: ObjectProperty
comment: Indicates that this port or group should be considered a "side chain" of some other port or group. The precise definition of "side chain" depends on the plugin, but in general this group should be considered a modifier to some other group, rather than an independent input itself.

sub-group of
type: Property
type: ObjectProperty
type: FunctionalProperty
domain: Port Group
range: Port Group
comment: Indicates that this group is a child of another group. This property has no meaning with respect to plugin execution, but the host may find this information useful (e.g. to provide a compact user interface). Note that being a sub-group does not relax the restriction that the group MUST have a unique symbol with respect to the plugin.

source
type: Property
type: ObjectProperty
domain: Output Group
range: Input Group
comment: Indicates that this port or group should be considered the "result" of some other port or group. This property only makes sense on groups with outputs when the source is a group with inputs. This can be used to convey a relationship between corresponding input and output groups with different types, e.g. a mono->stereo plugin.

main input
type: Property
type: ObjectProperty
type: FunctionalProperty
domain: Plugin
range: Input Group
comment: Indicates that this group should be considered the "main" input, i.e. the primary task is processing the signal in this group. A plugin MUST NOT have more than one pg:mainInput property.

main output
type: Property
type: ObjectProperty
type: FunctionalProperty
domain: Plugin
range: Output Group
comment: Indicates that this group should be considered the "main" output. The main output group SHOULD have the main input group as a pg:source.

group
type: Property
type: ObjectProperty
type: FunctionalProperty
domain: Port
range: Port Group
comment: Indicates that this port is a part of a group of ports on the plugin. The port should also have an lv2:designation property to define its designation within that group.

DiscreteGroup
type: Class
subclass of: Port Group
comment: "Discrete" channel configurations. These groups are divided into channels where each represents a particular speaker location. The position of sound in one of these groups depends on a particular speaker configuration.

left
type: Channel

right
type: Channel

center
type: Channel

side
type: Channel

center left
type: Channel

center right
type: Channel

side left
type: Channel

side right
type: Channel

rear left
type: Channel

rear right
type: Channel

rear center
type: Channel

low-frequency effects
type: Channel

Mono
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: center

Stereo
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: right

Mid-Side Stereo
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: center
element:
  index: 1
  designation: side

3.0 Surround
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: right
element:
  index: 2
  designation: rear center

4.0 Surround (Quadraphonic)
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: center
element:
  index: 2
  designation: right
element:
  index: 3
  designation: rear center

5.0 Surround (3-2 stereo)
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: center
element:
  index: 2
  designation: right
element:
  index: 3
  designation: rear left
element:
  index: 4
  designation: rear right

5.1 Surround (3-2 stereo)
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: center
element:
  index: 2
  designation: right
element:
  index: 3
  designation: rear left
element:
  index: 4
  designation: rear right
element:
  index: 5
  designation: low-frequency effects

6.1 Surround
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: center
element:
  index: 2
  designation: right
element:
  index: 3
  designation: side left
element:
  index: 4
  designation: side right
element:
  index: 5
  designation: rear center
element:
  index: 6
  designation: low-frequency effects

7.1 Surround
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: center
element:
  index: 2
  designation: right
element:
  index: 3
  designation: side left
element:
  index: 4
  designation: side right
element:
  index: 5
  designation: rear left
element:
  index: 6
  designation: rear right
element:
  index: 7
  designation: low-frequency effects

7.1 Surround (Wide)
type: Class
subclass of: DiscreteGroup
element:
  index: 0
  designation: left
element:
  index: 1
  designation: center left
element:
  index: 2
  designation: center
element:
  index: 3
  designation: center right
element:
  index: 4
  designation: right
element:
  index: 5
  designation: rear left
element:
  index: 6
  designation: rear right
element:
  index: 7
  designation: low-frequency effects

AmbisonicGroup
type: Class
subclass of: Port Group
comment: "Ambisonic" channel configurations. These groups are divided into channels which together represent a position in an abstract n-dimensional space. The position of sound in one of these groups does not depend on a particular speaker configuration; a decoder can be used to convert an ambisonic stream for any speaker configuration.

Ambisonic B stream of horizontal order 1 and peripheral order 0.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN3

Ambisonic B stream of horizontal order 1 and peripheral order 1.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN2
element:
  index: 3
  designation: ACN3

Ambisonic B stream of horizontal order 2 and peripheral order 0.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN3
element:
  index: 3
  designation: ACN4
element:
  index: 4
  designation: ACN8

Ambisonic B stream of horizontal order 2 and peripheral order 1.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN2
element:
  index: 3
  designation: ACN3
element:
  index: 4
  designation: ACN4
element:
  index: 5
  designation: ACN8

Ambisonic B stream of horizontal order 2 and peripheral order 2.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN2
element:
  index: 3
  designation: ACN3
element:
  index: 4
  designation: ACN4
element:
  index: 5
  designation: ACN5
element:
  index: 6
  designation: ACN6
element:
  index: 7
  designation: ACN7
element:
  index: 8
  designation: ACN8

Ambisonic B stream of horizontal order 3 and peripheral order 0.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN3
element:
  index: 3
  designation: ACN4
element:
  index: 4
  designation: ACN8
element:
  index: 5
  designation: ACN9
element:
  index: 6
  designation: ACN15

Ambisonic B stream of horizontal order 3 and peripheral order 1.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN2
element:
  index: 3
  designation: ACN3
element:
  index: 4
  designation: ACN4
element:
  index: 5
  designation: ACN8
element:
  index: 6
  designation: ACN9
element:
  index: 7
  designation: ACN15

Ambisonic B stream of horizontal order 3 and peripheral order 2.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN2
element:
  index: 3
  designation: ACN3
element:
  index: 4
  designation: ACN4
element:
  index: 5
  designation: ACN5
element:
  index: 6
  designation: ACN6
element:
  index: 7
  designation: ACN7
element:
  index: 8
  designation: ACN8
element:
  index: 9
  designation: ACN9
element:
  index: 10
  designation: ACN15

Ambisonic B stream of horizontal order 3 and peripheral order 3.
type: Class
subclass of: AmbisonicGroup
element:
  index: 0
  designation: ACN0
element:
  index: 1
  designation: ACN1
element:
  index: 2
  designation: ACN2
element:
  index: 3
  designation: ACN3
element:
  index: 4
  designation: ACN4
element:
  index: 5
  designation: ACN5
element:
  index: 6
  designation: ACN6
element:
  index: 7
  designation: ACN7
element:
  index: 8
  designation: ACN8
element:
  index: 9
  designation: ACN9
element:
  index: 10
  designation: ACN10
element:
  index: 11
  designation: ACN11
element:
  index: 12
  designation: ACN12
element:
  index: 13
  designation: ACN13
element:
  index: 14
  designation: ACN14
element:
  index: 15
  designation: ACN15