diff options
Diffstat (limited to 'ns/ext/atom/atom.ttl')
| -rw-r--r-- | ns/ext/atom/atom.ttl | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/ns/ext/atom/atom.ttl b/ns/ext/atom/atom.ttl new file mode 100644 index 0000000..0ef3b34 --- /dev/null +++ b/ns/ext/atom/atom.ttl @@ -0,0 +1,436 @@ +# LV2 Atom Extension +# Copyright 2007-2011 David Robillard <d@drobilla.net> +# +# Permission to use, copy, modify, and/or distribute this software for any +# purpose with or without fee is hereby granted, provided that the above +# copyright notice and this permission notice appear in all copies. +# +# THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + +@prefix atom: <http://lv2plug.in/ns/ext/atom#> . +@prefix doap: <http://usefulinc.com/ns/doap#> . +@prefix foaf: <http://xmlns.com/foaf/0.1/> . +@prefix lv2: <http://lv2plug.in/ns/lv2core#> . +@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> . +@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . +@prefix xsd: <http://www.w3.org/2001/XMLSchema#> . +@prefix owl: <http://www.w3.org/2002/07/owl#> . + +<http://lv2plug.in/ns/ext/atom> + a lv2:Specification ; + doap:name "LV2 Atom" ; + doap:shortdesc "A generic value container and several data types." ; + doap:license <http://opensource.org/licenses/isc-license> ; + rdfs:seeAlso <atom-buffer.h> ; + doap:release [ + doap:revision "0.2" ; + doap:created "2011-11-05" + ] ; + doap:maintainer [ + a foaf:Person ; + foaf:name "David Robillard" ; + foaf:homepage <http://drobilla.net/> ; + rdfs:seeAlso <http://drobilla.net/drobilla.rdf> + ] ; + lv2:documentation """ +<p>This extension defines a generic format for a typed piece of data, called an +lv2:Atom (e.g. integers, strings, buffers, data structures, +etc). Atoms allow LV2 plugins and hosts to communicate, process, serialise, +and store values of any type via a generic mechanism (e.g. LV2 ports, events, +disk, shared memory, network). Atoms are, with one exception, Plain +Old Data (POD) and may be safely copied (e.g. with a simple call to +<code>memcpy</code>).</p> + +<p>Since Atom communication can be implemented generically, plugins that +understand some type can be used together in a host that does not understand +that type, and plugins (e.g. routers, delays) can process atoms of unknown +type.</p> + +<p>An Atom can be trivially constructed in-place from an +<a href="http://lv2plug.in/ns/ext/event#Event">Event</a> as defined by the +<a href="http://lv2plug.in/ns/ext/event">LV2 Event</a> extension. In other +words, an Event is simply an Atom with a time stamp header. Atoms SHOULD +be used anywhere a "value" needs to be stored or communicated, to allow +implementations to be polymorphic and extensible.</p> + +<p>Atoms (the start of the LV2_Atom header) MUST be 32-bit aligned.</p> + +<p>Atoms can be communicated in many ways. Since an Atom is the payload of an +Event, an <a href="http://lv2plug.in/ns/ext/event#EventPort">EventPort</a> can +be used for communicating Atoms in realtime with sub-sample time stamp +accuracy. This extension also defines two port types for connecting directly +to a single Atom: atom:ValuePort and atom:MessagePort, which both have the same +buffer format but different semantics (with respect to how the run() callback +interprets the Atom).</p> + +<p>Implementing this extension requires a facility for mapping URIs to +integers, such as the <a href="http://lv2plug.in/ns/ext/urid">LV2 URID</a> +extension.</p> +""" . + +atom:Atom + a rdfs:Class ; + rdfs:label "Atom" ; + atom:cType "LV2_Atom" ; + lv2:documentation """ +<p>Abstract base class for all atoms. An LV2_Atom has a 32-bit +<code>type</code> and <code>size</code> followed by a <code>body</code> of +<code>size</code> bytes.</p> + +<p>All concrete Atom types (subclasses of this class) MUST define a precise +binary layout for <code>body</code>.</p> + +<p>The <code>type</code> field is the URI of a subclass of Atom mapped to an +integer using the <a href="http://lv2plug.in/ns/ext/uri-map">URI Map</a> +extension's LV2_URI_Map_Feature::uri_to_id() with +<code>map = "http://lv2plug.in/ns/ext/event"</code>. If a plugin or host +does not understand <code>type</code>, that atom SHOULD be gracefully ignored +(or copied if it does not have type 0).</p> + +<p>All atoms are POD by definition except references, which as a special case +have <code>type = 0</code>. An Atom MUST NOT contain a Reference. It is safe +to copy any non-reference Atom with a simple <code>memcpy</code>, even if the +implementation does not understand <code>type</code>. Though this extension reserves +the type 0 for references, actual specification of how references are used is left +to another extension.</p> +""" . + +atom:String + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "String" ; + atom:cType "LV2_Atom_String" ; + lv2:documentation """ +<p>A UTF-8 encoded string.</p> + +<p>The body of an LV2_Atom_String is a C string in UTF-8 encoding, i.e. an +array of bytes (<code>uint8_t</code>) terminated with a NULL byte +(<code>'\\0'</code>).</p> + +<p>This type can be used for free-form strings, but in most cases it is better to +use atom:Literal since this supports a language tag or datatype. Implementations +SHOULD NOT use atom:String unless translating the string does not make sense and +the string has no meaningful datatype.</p> +""" . + +atom:Literal + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "String Literal" ; + atom:cType "LV2_Atom_Literal" ; + lv2:documentation """ +<p>A UTF-8 encoded string literal, with an optional datatype or language.</p> + +<p>This type is compatible with rdf:Literal and is capable of expressing a +string in any language, or a value of any type. A Literal has a +<code>datatype</code> and <code>lang</code> followed by string data in UTF-8 +encoding. The length of the string data in bytes is <code>size - +sizeof(LV2_Atom_Literal)</code>, including the terminating NULL character. The +<code>lang</code> field SHOULD be a URI of the form +<http://lexvo.org/id/term/LANG> where LANG is an <a +href="http://www.loc.gov/standards/iso639-2/">ISO 693-2</a> or <a +href="http://www.loc.gov/standards/iso639-2/">ISO 693-3</a> language code.</p> + +<p>For compatibility, a Literal MUST have either a <code>datatype</code> +or a <code>lang</code>, but never both.</p> + +<p>For example, a Literal can be "Hello" in English:</p> +<pre class="c-code"> +void set_to_hello_in_english(LV2_Atom_Literal* lit) { + lit->type = map(expand("atom:Literal")); + lit->size = 14; + lit->datatype = 0; + lit->lang = map("http://lexvo.org/id/term/en"); + memcpy(lit->str, "Hello", sizeof("Hello")); // Assumes enough space +} +</pre> + +<p>or a Turtle string:</p> +<pre class="c-code"> +void set_to_turtle_string(LV2_Atom_Literal* lit, const char* ttl) { + lit->type = map(expand("atom:Literal")); + lit->size = 64; + lit->datatype = map("http://www.w3.org/2008/turtle#turtle"); + lit->lang = 0; + memcpy(lit->str, ttl, strlen(ttl) + 1); // Assumes enough space +} +</pre> +""" . + +atom:URID + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Integer ID mapped from a URI" ; + atom:cType "LV2_Atom_ID" ; + lv2:documentation """ +<p>An unsigned 32-bit integer mapped from a URI using the <a +href="http://lv2plug.in/ns/ext/uri-map">URI Map</a> extension's +LV2_URI_Map_Feature::uri_to_id() with <code>map = NULL</code>.</p> +""" . + +atom:BlankID + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Integer ID for a blank node" ; + atom:cType "LV2_Atom_ID" ; + lv2:documentation """ +<p>An unsigned 32-bit integer identifier for a blank node. A BlankID is only +meaningful within a limited scope (e.g. the Atom in which it appears), and +MUST NOT be used as a global identifier. In particular, a BlankID is NOT a +URID, and can not be mapped to/from a URI.</p> +""" . + +atom:Vector + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Vector" ; + atom:cType "LV2_Atom_Vector" ; + lv2:documentation """ +<p>A homogeneous sequence of atoms with equivalent type and size.</p> + +<p>An LV2_Atom_Vector is a 32-bit <code>elem_count</code> and +<code>elem_type</code> followed by <code>elem_count</code> atom bodies of type +<code>elem_type</code>. The element type must be a fixed size atom:Atom type, +i.e. the size of each element is the vector's <code>size / +elem_count</code>.</p> + +<p>For example, an atom:Vector containing 42 elements of type atom:Float:</p> +<pre class="c-code"> +struct VectorOf42Floats { + uint32_t type; // map(expand("atom:Vector")) + uint32_t size; // sizeof(LV2_Atom_Vector) + (42 * sizeof(float); + uint32_t elem_count; // 42 + uint32_t elem_type; // map(expand("atom:Float")) + float elems[32]; +}; +</pre> + +<p>Note that it is possible to construct a valid Atom for each element +of the vector, even by an implementation which does not understand +<code>elem_type</code>.</p> +""" . + +atom:Tuple + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Tuple" ; + lv2:documentation """ +<p>A sequence of lv2:Atom with varying <code>type</code> +and <code>size</code>.</p> + +<p>The body of a Tuple is simply a sequence of complete atoms, each aligned to +32 bits.</p> +""" . + +atom:Thing + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Thing" ; + atom:cType "LV2_Thing" ; + lv2:documentation """ +<p>Abstract base class for a "Thing", i.e. an atom:Atom with a +number of <a href="#Property">properties</a>. An LV2_Object is an unsigned +32-bit integer <code>context</code> and <code>id</code> followed by a sequence +of LV2_Atom_Property .</p> + +<p>The <code>context</code> is mapped using the <a +href="http://lv2plug.in/ns/ext/uri-map">URI Map</a> extension's +LV2_URI_Map_Feature::uri_to_id() with <code>map = NULL</code>, and may be 0 +(the default context).</p> + +<p>Note this is an abstract class, i.e. no Atom can exist with <code>type = +uri_to_id(atom:Thing)</code>. An Object is either an atom:Resource or an +atom:Blank, but the <code>body</code> always has the same binary format, +LV2_Object. Thus, both named and anonymous objects can be handled with common +code using only a 64-bit header for both.</p> +""" . + +atom:Resource + a rdfs:Class ; + rdfs:subClassOf atom:Thing ; + atom:cType "LV2_Thing" ; + lv2:documentation """ +<p>An atom:Thing where <code>id</code> is the URI of the resource mapped to an +atom:URID.</p> +""" . + +atom:Blank + a rdfs:Class ; + rdfs:subClassOf atom:Thing ; + atom:cType "LV2_Thing" ; + lv2:documentation """ +<p>An atom:Thing where <code>id</code> is the blank node ID of the object, +which is only meaningful within a certain limited scope (e.g. the container of +the Blank) and MUST NOT be used as a global ID. In particular, <code>id</code> +is NOT an <a href="ID">ID</a>.</p> +""" . + +atom:Message + a rdfs:Class ; + rdfs:subClassOf atom:Thing ; + atom:cType "LV2_Thing" ; + lv2:documentation """ +<p>A atom:Thing where <code>id</code> is a message type ID. Conceptually, a +Message is identical to a Blank, but is a distinct type with a single type +field to allow simple and fast dispatch by handling code.</p> + +<p>A Message may be serialised as a Blank by adding an rdf:type property with +the value <code>id</code> unmapped to a URI.</p> +""" . + +atom:Event + a rdfs:Class ; + rdfs:label "Event" ; + atom:cType "LV2_Atom_Event" ; + lv2:documentation """ +<p>An atom with a time stamp header prepended, typically for sample accurate +transmission via LV2 ports. See struct LV2_Atom_Event.</p> +""" . + +atom:Bang + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Bang (activity) (size = 0)" . + +atom:Number + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Number (abstract class)." . + +atom:Int32 + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "Signed 32-bit integer" ; + atom:cType "LV2_Atom_Int32" . + +atom:Int64 + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "Signed 64-bit integer" ; + atom:cType "LV2_Atom_Int64" . + +atom:Bool + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "An atom:Int32 where 0 is false and all other values true" ; + atom:cType "LV2_Atom_Int32" . + +atom:Float + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "32-bit IEEE-754 floating point number" ; + atom:cType "LV2_Atom_Float" . + +atom:Double + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "64-bit IEEE-754 floating point number" ; + atom:cType "LV2_Atom_Double" . + +atom:blobSupport + a lv2:Feature ; + rdfs:label "Blob support" ; + lv2:documentation """ +<p>Support for dynamically allocated blobs. If a host supports this feature, +it MUST pass a LV2_Feature with <code>URI</code> +http://lv2plug.in/ns/ext/atom#blobSupport and <code>data</code> pointing to a +LV2_Blob_Support.</p> +""" . + +atom:AtomPort + a rdfs:Class ; + rdfs:subClassOf lv2:Port ; + rdfs:label "Atom Port" ; + lv2:documentation """ +<p>A port which contains an lv2:Atom. Ports of this type will +be connected to a 32-bit aligned LV2_Atom immediately followed by +<code>size</code> bytes of data.</p> + +<p>This is an abstract port type, i.e. a port MUST NOT only be an AtomPort, +but must be a more descriptive type that is a subclass of AtomPort which +defines the port's semantics (typically atom:ValuePort or atom:MessagePort). +</p> + +<p>Before calling a method on the plugin that writes to an AtomPort output, +the host MUST set the size of the Atom in that output to the amount of +available memory immediately following the Atom header. The plugin MUST +write a valid Atom to that port (leaving it untouched is illegal). If there +is no reasonable value to write to the port, the plugin MUST write NULL +(the Atom with both <code>type = 0</code> and <code>size = 0</code>).</p> +""" . + +atom:ValuePort + a rdfs:Class ; + rdfs:subClassOf atom:AtomPort ; + rdfs:label "Value Port" ; + lv2:documentation """ +<p>An AtomPort that interprets its data as a persistent and time-independent +"value".</p> +<ul> +<li>If a plugin has fixed input values for all ports, all ValuePort outputs +are also fixed regardless of the number of times the plugin is run.</li> +<li>If a plugin has fixed input values for all ports except a ValuePort, +each value V of that ValuePort corresponds to a single set of outputs +for all ports.</li> +<li>If a ValuePort contains a reference then the blob it refers to is +constant; plugin MUST NOT modify the blob in any way.</li> +</ul> +<p>Value ports can be thought of as purely functional ports: if a plugin +callback has only value ports, then the plugin callback is a pure function.</p> +""" . + +atom:MessagePort + a rdfs:Class ; + rdfs:subClassOf atom:AtomPort ; + rdfs:label "Message Port" ; + rdfs:comment """ +An AtomPort that "receives", "consumes", "executes", or "sends" its value. +The Atom contained in a MessagePort is considered transient and/or +time-dependent, and is only valid for a single run invocation. Unlike a +ValuePort, a MessagePort may be used to manipulate internal plugin state. + +Intuitively, a MessagePort contains a "message" or "command" or "event" +which is reacted to, NOT a "value" or "signal" (which is computed with). +""" . + +atom:cType + a rdf:Property , + owl:DatatypeProperty ; + rdfs:label "C type" ; + rdfs:domain rdfs:Class ; + rdfs:range xsd:string ; + rdfs:comment """ +The identifier for a C type describing the in-memory representation of +an instance of this class. +""" . + +atom:EventPort + a rdfs:Class ; + rdfs:label "Event port" ; + rdfs:subClassOf lv2:Port ; + lv2:documentation """ +<p>A port used for communicating time-stamped atoms in the audio context. +Ports of this type are connected to an LV2_Atom_Buffer, which contains a flat +time-stamped sequence of atom:Event.</p> + +<p>This port type is intended as a simpler and atom compatible successor to <a +href="http://lv2plug.in/ns/ext/event#EventPort">ev:EventPort</a>.</p> +""" . + +atom:supports + a rdf:Property ; + rdfs:domain lv2:Port ; + rdfs:range atom:Atom ; + rdfs:label "supports" ; + lv2:documentation """ +<p>Indicates that a Port supports a certain atom:Atom type. This is distinct from +the port type - e.g. the port type ValuePort can hold atoms with many different +types. This property is used to describe which Atom types a Port expects to +receive or send.</p> +""" . |