LV2 Specifications

This is an index of all official LV2 specifications. These pages are high-level descriptions of each specification, and vocabulary references with API links where appropriate. A global API reference is also available.

Version 1.10.0 (2014-08-08)

• Fix -Wconversion warnings in headers.
• lv2specgen: Display deprecated warning on classes marked owl:deprecated.
• Upgrade to waf 1.7.16.
• lv2core: Clarify lv2_descriptor() and lv2_lib_descriptor() documentation.
• atom: Add lv2_atom_forge_key() for terser object writing.
• atom: Add lv2_atom_sequence_clear() and lv2_atom_sequence_append_event() helper functions.
• atom: Add lv2_atom_forge_is_object_type() and lv2_atom_forge_is_blank() to ease backwards compatibility.
• atom: Deprecate Blank and Resource in favour of just Object.
• event: Minor documentation improvements.
• patch: Add patch:sequenceNumber for associating replies with requests.
• ui: Add show interface so UIs can gracefully degrade to separate windows if hosts can not use their widget directly.
• ui: Fix identifier typos in documentation.

Version 1.8.0 (2014-01-04)

• Install lv2specgen for use by other projects.
• Add scope example plugin from Robin Gareus.
• lv2specgen: Fix links to externally defined terms.
• lv2core: Add lv2:prototype for property inheritance.
• atom: Make lv2_atom_*_is_end() arguments const.
• log: Add missing include string.h to logger.h for memset.
• ui: Fix LV2_UI_INVALID_PORT_INDEX identifier in documentation.

Version 1.6.0 (2013-08-09)

• Fix lv2specgen usage from command line.
• Fix port indices of metronome example.
• Upgrade to waf 1.7.11.
• atom: Fix crash in forge.h when pushing atoms to a full buffer.
• ui: Add idle interface so native UIs and foreign toolkits can drive their event loops.
• ui: Add ui:updateRate property.

Version 1.6 (2013-05-26)

• Fix crash in forge.h when pushing atoms to a full buffer.

Version 2.14 (2013-03-18)

• Add ui:updateRate property.
• Add idle interface so native UIs and foreign toolkits can drive their event loops.

Version 1.4.0 (2013-02-17)

• Add metronome example plugin to demonstrate sample accurate tempo sync.
• Generate book-style HTML documentation from example plugins.
• lv2core: Reserve minor version 0 for unstable development plugins.
• lv2core: Make lv2:Parameter rdfs:subClassOf rdf:Property.
• lv2core: Add lv2:EnvelopePlugin class.
• lv2core: Set range of lv2:designation to lv2:Designation.
• lv2core: Add lv2:control for designating primary event-based control ports.
• atom: Remove atom:stringType in favour of owl:onDatatype so generic tools can understand and validate atom literals.
• atom: Fix lv2_atom_sequence_end().
• atom: Improve atom documentation.
• buf-size: Fix typo in bufsz:sequenceSize label.
• event: Fix incorrect return type in lv2_event_get().
• log: Add logger convenience API.
• options: Set the range of opts:requiredOption and opts:supportedOption to opts:Option.
• patch: Make patch:Set a compact message for setting one property.
• patch: Add patch:readable and patch:writable for describing available properties.
• state: Add state:loadDefaultState feature so plugins can have their default state loaded without hard-coding default state as a special case.
• ui: Fix incorrect linker flag in ui:makeSONameResident documentation.

Version 1.4 (2013-01-27)

• Improve atom documentation.
• Remove atom:stringType in favour of owl:onDatatype so generic tools can understand and validate atom literals.
• Fix lv2_atom_sequence_end().

Version 2.0 (2013-01-16)

• Add state:loadDefaultState feature so plugins can have their default state loaded without hard-coding default state as a special case.

Version 1.10 (2013-01-13)

• Fix incorrect return type in lv2_event_get().

Version 2.0 (2013-01-10)

• Make patch:Set a compact message for setting one property.
• Add patch:readable and patch:writable for describing available properties.

Version 2.0 (2013-01-08)

• Add logger convenience API.

Version 1.2 (2012-12-21)

• Fix typo in bufsz:sequenceSize label.

Version 2.12 (2012-12-01)

• Fix incorrect linker flag in ui:makeSONameResident documentation.

Version 1.2.0 (2012-10-14)

• Use stricter datatype definitions conformant with the XSD and OWL specifications for better validation.
• Move all project metadata for extensions (e.g. change log) to separate files to spare hosts from loading them during discovery.
• lv2core: Use consistent label style.
• atom: Fix lv2_atom_object_next() on 32-bit platforms.
• atom: Add LV2_ATOM_CONTENTS_CONST and LV2_ATOM_BODY_CONST.
• atom: Add lv2_atom_object_body_get().
• atom: Fix implicit conversions in forge.h that are invalid in C++11.
• atom: Fix outdated documentation in forge.h.
• atom: Use consistent label style.
• buf-size: Initial release.
• dynmanifest: Use consistent label style.
• event: Remove asserts from event-helper.h.
• event: Make event iterator gracefully handle optional ports.
• event: Use consistent label style.
• event: Use more precise domain and range for EventPort properties.
• midi: Add C definitions for message types and standard controllers.
• midi: Use consistent label style.
• midi: Fix definition of SystemExclusive status byte.
• midi: Add midi:binding and midi:channel predicates.
• midi: Add midi:HexByte datatype for status bytes and masks.
• midi: Remove non-standard midi:Tick message type.
• morph: Initial release.
• options: Initial release.
• parameters: Use consistent label style.
• parameters: Add param:sampleRate.
• parameters: Add parameters.h of URI defines for convenience.
• port-groups: Use consistent label style.
• port-props: Use consistent label style.
• presets: Use consistent label style.
• state: Use consistent label style.
• time: Use consistent label style.
• urid: Fix typo in urid:unmap documentation.
• ui: Use consistent label style.
• ui: Add missing LV2_SYMBOL_EXPORT declaration for lv2ui_descriptor prototype.
• ui: Add types for WindowsUI, CocoaUI, and Gtk3UI.
• units: Remove units:name in favour of rdfs:label.
• units: Use consistent label style.

Version 8.0 (2012-04-17)

• Relax the range of lv2:index so it can be used for things other than ports.
• Add lv2:CVPort.
• Fix LV2_SYMBOL_EXPORT and lv2_descriptor prototype for Windows.
• Remove lv2:Resource, which turned out to be meaningless.
• Add metadata concept of a designation, a channel or parameter description which can be assigned to ports for more intelligent use by hosts.
• Add new discovery API which allows libraries to read bundle files during discovery, makes library construction/destruction explicit, and adds extensibility to prevent future breakage.
• Merge with unified LV2 package.

Version 1.0.0 (2012-04-16)

• Initial release as a unified project. Projects can now simply depend on the pkg-config package 'lv2' for all official LV2 APIs.
• New extensions: atom, log, parameters, patch, port-groups, port-props, resize-port, state, time, worker.
• lv2core: Merge with unified LV2 package.
• lv2core: Add lv2:CVPort.
• lv2core: Add new discovery API which allows libraries to read bundle files during discovery, makes library construction/destruction explicit, and adds extensibility to prevent future breakage.
• lv2core: Relax the range of lv2:index so it can be used for things other than ports.
• lv2core: Remove lv2:Resource, which turned out to be meaningless.
• lv2core: Add metadata concept of a designation, a channel or parameter description which can be assigned to ports for more intelligent use by hosts.
• lv2core: Fix LV2_SYMBOL_EXPORT and lv2_descriptor prototype for Windows.
• atom: Initial release.
• data-access: Merge with unified LV2 package.
• dynmanifest: Merge with unified LV2 package.
• event: Fix bug in lv2_event_reserve().
• event: Merge with unified LV2 package.
• event: Fix incorrect ranges of some properties.
• instance-access: Merge with unified LV2 package.
• log: Initial release.
• midi: Add class definitions for various message types.
• midi: Merge with unified LV2 package.
• midi: Document how to serialise a MidiEvent to a string.
• parameters: Initial release.
• patch: Initial release.
• port-groups: Initial release.
• port-props: Initial release.
• presets: Merge with unified LV2 package.
• presets: Add pset:preset property for describing the preset currently applied to a plugin instance.
• presets: Remove pset:appliesTo property, use lv2:appliesTo instead.
• resize-port: Initial release.
• state: Initial release.
• time: Initial release.
• uri-map: Merge with unified LV2 package.
• urid: Merge with unified LV2 package.
• urid: Add feature struct names.
• worker: Initial release.
• ui: Add port protocols and a dynamic notification subscription mechanism, for more flexible communication, and audio port metering without control port kludges.
• ui: Add touch feature to notify the host that the user has grabbed a control.
• ui: Add ui:parent and ui:resize.
• ui: Add support for referring to ports by symbol.
• ui: Merge with unified LV2 package.
• ui: Add ui:portMap for accessing ports by symbol, allowing for UIs to be distributed separately from plugins.
• units: Add header of URI defines.
• units: Add unit for audio frames.
• units: Merge with unified LV2 package.

Version 6.0 (2011-11-21)

• Improve documentation.
• Make lv2core.ttl a valid OWL 2 DL ontology.
• Add lv2:extensionData and lv2:ExtensionData for plugins to indicate that they support some URI for extension_data().
• Switch to the ISC license, a simple BSD-style license (with permission of all contributors to lv2.h and its ancestor, ladspa.h).
• Rename core.lv2 and lv2.ttl to lv2core.lv2 and lv2core.ttl to adhere to modern conventions.
• Remove lv2config in favour of the simple convention that specifications install headers to standard URI-based paths.

Version 1.0 (2011-11-21)

• Initial release.

Version 1.4 (2011-11-21)

• Update packaging.
• Deprecate uri-map in favour of urid.

Version 5.4 (2011-11-21)

• Update packaging.
• Make units.ttl a valid OWL 2 DL ontology.
• Improve documentation.
• Define used but undefined resources (units:name, units:render, units:symbol, units:Conversion, units:conversion, units:prefixConversion, units:to, and units:factor).

Version 2.4 (2011-11-21)

• Deprecate ui:makeSONameResident.
• Add Qt4 and X11 widget types.
• Install header to URI-based system path.
• Make ui.ttl a valid OWL 2 DL ontology.
• Add pkg-config file.

Version 2.2 (2011-11-21)

• Update packaging.
• Improve documentation.

Version 1.4 (2011-11-21)

• Improve documentation.
• Update packaging.

Version 1.4 (2011-11-21)

• Improve documentation.
• Update packaging.

Version 1.4 (2011-11-21)

• Update packaging.

Version 1.4 (2011-11-21)

• Improve documentation.
• Update packaging.

Version 1.2 (2011-05-26)

• Mark up documentation in HTML using lv2:documentation.
• Add build system (for installation).

Version 2.2 (2011-05-26)

• Add build system (for installation).
• Convert documentation to HTML and use lv2:documentation.
• Use lv2:Specification to be discovered as an extension.

Version 1.2 (2011-05-26)

• Switch to ISC license.
• Add build system for installation.

Version 1.2 (2011-05-26)

• Switch to ISC license.
• Add build system for installation.

Version 1.2 (2011-05-26)

• Convert documentation to HTML and use lv2:documentation.
• Use lv2:Specification to be discovered as an extension.
• Add build system (for installation).

Version 1.2 (2011-05-26)

• Switch to ISC license.
• Add build system for installation.

Version 4.0 (2011-03-18)

• Define lv2:minorVersion and lv2:microVersion (MUST be in manifest.ttl).
• Define run() pre-roll special case (sample_count == 0).
• Add lv2:FunctionPlugin and lv2:ConstantPlugin classes.
• Fix definition of lv2:minimum etc. (used for values, not scale points).
• Make doap:license suggested, but not required (for wrappers).
• Add lv2:enumeration port property.
• Move lv2:AmplifierPlugin under lv2:DynamicsPlugin.
• Define lv2:documentation and use it to document lv2core.
• Define lv2:binary (MUST be in manifest.ttl).
• Loosen domain of lv2:optionalFeature and lv2:requiredFeature (to allow re-use in extensions).
• Add generic lv2:Resource and lv2:PluginBase classes.
• Move project metadata to manifest.
• More precisely define properties with OWL.

Version 1.0 (2010-11-24)

• Initial release.

Version 1.0 (2010-10-18)

• Initial release.

Version 2.0 (2010-10-06)

• Initial release.

Version 5.2 (2010-10-05)

• Convert documentation to HTML and use lv2:documentation.
• Add build system (for installation).

Version 5.0 (2010-10-05)

• Initial release.
• Update packaging.
• Define used but undefined resources (units:name, units:render, units:symbol, units:Conversion, units:conversion, units:prefixConversion, units:to, and units:factor).
• Improve documentation.

Version 2.0 (2010-10-04)

• Initial release.

Version 1.0 (2010-10-04)

• Initial release.

Version 1.0 (2010-10-04)

• Initial release.

Version 1.0 (2010-10-04)

• Initial release.

Version 3.0 (2008-11-08)

• Minor stylistic changes to lv2.ttl.
• Require that serialisations refer to ports by symbol rather than index.
• No header changes.

Version 2.0 (2008-02-10)

• Initial release.