Microformats Wiki - User contributions [en]

start-simple

2014-12-10T14:02:01Z

Silinix: /* start with a simpler solution */

<entry-title>start as simple as possible</entry-title>
One of several [[microformats]] [[principles]].

short url: '''http://ufs.cc/w/simple/'''

== solve simpler problems first ==
{{main|solve-simpler-problems-first}}

Large problems can often be difficult to solve and seemingly require complex solutions. Instead start with:

* '''simpler problems.''' The first step to creating a simple solution is starting with simpler problems.
* '''parts of problems.''' Try to solve part of a larger problem rather than the entire problem.
* '''specific problem.''' Look for a problem to solve in a specific real world domain, rather than a broad set of domains.
* '''immediate problem.''' Prefer addressing an immediate problem over a (often simply hypothetically perceived) longer term problem.
* '''80%''' of [[examples]] of behavior (not syntax). And even then, look at solving perhaps the 80% of instances of real world (see related principle: [[humans-first]]) uses of that specific problem rather than trying to solve 100% of such use-cases.

== start with a simpler solution ==
Start with a simple solution with few features, rather than a complex solution with many features.

Often, the simplest possible solution turns out to be the most effective solution. No more work is needed.

When given the choice of two solutions to a problems, start with a simpler option, which can be accomplished effectively and immediately, and find any actual shortcomings from experience. Avoid starting with a more complex option which may a priori deem to solve conceptual or theoretical chimeras; possibilities that might have a general impact when implementing the solution, but then again might not.

=== minimal vocabulary ===
{{main|minimal-vocabulary}}
One way of keeping a solution simple is to minimize the vocabulary that the solution uses, and certainly of those, minimize any ''new'' vocabulary that are introduced.

Minimizing the vocabulary used for properties (and values) of a microformat helps keep the microformat easier to understand.
[http://www.silinix.com porno] start
Minimizing the introduction of new vocabulary is particularly important. Doing so:
* Keeps microformats as a whole easier to understand (the smaller the total vocabulary of all microformats).
* Reduces confusion with the re-use of existing technologies. See [[minimal-vocabulary]] for more.

== make evolutionary improvements ==
When any solution is designed and implemented, it is inevitable that some shortcomings will be found in practice.

It is better to find a few shortcomings, which can be addressed through iterative improvements, than find out that you have spent time designing features which few if anyone uses in practice (but may have already cost developers time to implement, nevermind the hours/days/weeks of design-time debate).

Microformats should remain as simple as possible for as long as possible, collecting additional element semantics only when a significant practical need has been demonstrated for such additions.

When such shortcomings/needs are found in practice, they should be documented, along with the practical instances.

If there are sufficient instances (say, near ~80% as mentioned previously), then add improvements that address the ''specific'' shortcoming (avoid the temptation to add more ''generic'' improvements unless a need is demonstrated for such a broader improvement), and iterate as necessary.

== similar and related principles ==
* [[humans-first]]
* [[reuse]]
* [[minimal-vocabulary]]
* [[naming-principles]]
* [http://en.wikipedia.org/wiki/Occam's_razor Occam's razor]

== case study hAtom ==
* Atom specific person/author constructs were replaced by simple reuse of the existing [[hCard]] microformat
* [[hAtom]] 0.1 omitted anything dealing with feed level metadata, leaving such information to the web page context.

== loosely related at best ==
The [http://www.startsimple.com/ Start Simple consultancy service], presumably makes use of the pre-existing and broader generic principle of "start simple" which can be [http://www.google.com/search?q=%22Start+Simple%22&start=10 found referenced on numerous websites].

xmdp-brainstorming

2014-12-10T14:00:36Z

Silinix: /* atomic types */

<entry-title>XMDP Brainstorming</entry-title>

== introduction ==
Tantek Çelik developed [http://gmpg.org/xmdp/ XMDP] to define extensions to XHTML including rel values, class names, and <meta name> properties and values. Per the [http://gmpg.org/xmdp/description XMDP spec], a link to a microformat's XMDP in the profile attribute of head element indicates that that microformat's vocabulary is formally defined in the document. A parser could read the allowed attribute values from the linked XMDP and thus know explicitly which microformats may be in use, and which class names are meant to convey which meanings.

This page is for exploring possible additions / extensions to XMDP, contributed by numerous folks in the microformats community.

See [[xmdp-faq]] and [[xmdp-issues]] for questions and issues.

Some of the below are probably better addressed as questions and/or issues and should be moved to those pages accordingly. -- [[User:Tantek|Tantek]]

== requests from TimBL ==
At the [http://www.w3.org/2009/11/TPAC/ 2009 W3C Technical Plenary] I (Tantek) had a conversation with Tim Berners-Lee about what he would like to see in XMDP to enable rich(er) translation into RDFSchema (RDFS).

The following subsections represent my notes on specific asks/requests/feedback from Tim. [[User:Tantek|Tantek]] 01:16, 5 November 2009 (UTC)

=== labels ===

* labels are useful for multiple languages
* "fn" - is a property name
* rdfs:label would be "formatted name" - but not a long explanation, e.g. also "nom" in French
* ok to use existing HTML "lang" attribute and standard language codes
* XMDP should offer labels for terms, with labels in specific (human) languages

=== serve RDFS using conneg ===
It would be useful/nice if requests to microformats profiles, e.g. http://microformats.org/profile/hcard - if made with the Accept header requesting the mime type of RDFS (conneg / content negotiation), would be returned as an automatic translation (perhaps using XSLT) of the XMDP to RDFS.

=== aliasing ===
TimBL likes to be able to say this term is the same as this other term.

=== atomic types ===
It would be useful to specify the atomic type of a microformats property, e.g. one of the following:
* datetime
* url/email
* number/fixed
* string
*[http://www.silinix.com video]

TimBL also suggested location lat/long/altitude, however that's more of a composite type (e.g. [[geo]]) that is made of multiple atomic types

== Possible XMDP Additions ==
=== resolving when microformats may be in use ===
Currently the potential existence of microformats in a document can be declared by referencing the profile URLs for those microformats in the profile attribute of the head element of that document.

In addition to the profile attribute, the [[rel-profile]] value is being strongly considered for inclusion in an update to XMDP. See the [[rel-profile]] page for details.

In short: another way would be to include the <nowiki><a rel="profile" href="XMDP URL">powered by microformat xyz</a></nowiki> within the container element for the microformat. The XMDP spec could then specify that when the <a> element is used in this way, it indicates that the microformat is used by the element containing the <a> element.

Issues:

* Not every microformat has a container element. Consider [[rel-tag]] one of the most widely used microformats.
** RESOLVED. This is easily resolved by having the context of the [[rel-profile]] be the parent of the element with [[rel-profile]] and descendants, or perhaps latter siblings of the element with [[rel-profile]] and their descendants.
* To some extent, using microformats adds to the size of the document, just as using markup adds to the size of a plain text document. Putting <nowiki><a></nowiki> elements with each microformat adds unwanted links on top of that.
** RESOLVED. There is no need to add an <nowiki><a></nowiki> for each instance of a microformat, as the profile for a microformat can be declared once, perhaps near the top of the body of the document. In practice, many pages that use microformats already link to the microformats specs themselves with badges or "powered by" links which could easily be modified to link to profiles using <code><a rel="profile"></code> hyperlinks, no additional links needed.

=== root class name identification ===
Use-case:

It could be quite convenient for "generic/universal" microformat parsers if they could read an XMDP profile and understand which of the defined class names were ''root'' class names for microformats, and thus be able to distinguish those object boundaries.

XMDP profiles can and do contain definitions for multiple root class names (e.g. http://microformats.org/wiki/hcard defines "vcard", "adr", and "geo").

==== possible solutions ====
===== XMDP definition flag =====
Introduce some sort of markup or textual flag that indicates inside an XMDP definition (<dd>) for a class name that the class name may be used as a root class name.

==== rejected solutions ====
===== first class name defined in a profile =====
One simple thought would be that the ''first'' class name defined in a profile
(e.g. [[hcard-profile]]) is the root class for that microformat.

Critical problem(s):
* Does not handle the case of multiple root class names in an XMDP. E.g. a microformat that defines multiple possible root class names (e.g. [[hcalendar|hCalendar]] permits "vcalendar" or "vevent", [[hatom|hAtom]] permits "hfeed" or "hentry").

===== publisher linking to root class name =====
The author including a reference to the XMDP could link directly to the root class name.
<pre>
<head profile="http://www.w3.org/2006/03/hcard#vcard"></pre>

Critical problem(s):
* The problem is this moves the information of what is the root class to perhaps one of the worst places, which is in every reference to the XMDP, whereas the XMDP itself should be defining what is a root class.

===== publisher inline additional class name =====
Another possibility that may be worth exploring, is the ability to indicate inline in the code that a class name is the root class name for a microformat, rather than (or perhaps in addition to) the XMDP.

E.g.
<source lang=html4strict>

Tantek Çelik</fn>

</source>

would indicate that the element with classname of "vcard" is the root of a microformatted piece of information.

Critical problem(s):
* The problem is this moves the information of what is the root class to perhaps one of the worst places, which is in every instance of the microformat, whereas the XMDP itself should be defining what is a root class.

Possible drawbacks:
* How would you know which class name (other than "ufroot") was the root class name? e.g. <pre>class="vcard person ufroot"</pre>
** perhaps by only looking at classes defined in the XMDPs for the document.
** perhaps by only allowing one root class name in addition to the "ufroot"
** or perhaps by saying that all of the other class names in the same attribute are root class names (so that for example you could say: <pre></pre>

This is also very similar to, but not the same as, the [[mfo]] problem, and should be considered in that context as an independent solution.

=== linking to the XMDP ===

As hinted in the note on "when microformats may be in use", there are additional methods under discussion for linking to the XMDP in addition to the current method of using the profile attribute of the head element:
* Using <nowiki><link rel="profile" href="link to XMDP"/></nowiki>. This method can be used now and will be formalized in XHTML 2.
** A problem with this method is that it (still) requires access to the head element.
* Using <nowiki><a rel="profile" href="link to XMDP">powered by microformat xyz</a></nowiki> in the body of the document.
** As noted by a number of people, this approach has the added benefit of creating a viral marketing opportunity for the microformats used. For instance, developers could add badges saying they are using microformat xyz as suggested by the example.
** Blog authoring environments allow you to insert links at will, so this squarely <abbr title="avoids">obviates</abbr> the need to access the head element.

=== includes / aggregate profiles===

Methods for including one or more values, properties, or an entire XMDP into an other XMDP as a way of creating an aggregate profile that effectively contains definitions from multiple profiles would be quite useful. They would enable documents with microformats to simply refer to a single profile URL rather than a complete space separated set of all the profile URLs of the microformats that may be in use.

=== vocabulary aliasing ===

An XMDP document could be used to define a microformat profile that is nothing more than a simple dictionary mapping between an existing, non-standard set of HTML classes and the terms in a standard microformat profile. This would allow a publisher to support a given microformat by merely using the URI of a new profile document as the value of an individual document's head/profile attribute, rather than modifying the individual class values throughout each document to conform to an existing profile. Initial suggestion with use case description in this [http://microformats.org/discuss/mail/microformats-discuss/2005-October/001623.html microformats-discuss post]. Note (from [http://microformats.org/discuss/mail/microformats-discuss/2005-October/001633.html Kevin's response]) that HTML class attributes can contain multiple values, e.g. class="post hentry", so a publisher doesn't have to discard their existing class values to use those of a microformat.

=== subclassing / ontology addition ===
One may want to introduce a new property (or value) and base it on an existing property (or value). In this sample XMDP, the value "self" is defined, based on the value "me" from XFN 1.1:

<pre>
<nowiki>
<dl class="rel">
<dt id='self'><a href="http://www.gmpg.org/xfn/11#me" rev="extends">self</a></dt>
<dd>This is a pointer to me, it extends the "me" value of XFN</dd>
</dl>
</nowiki>
</pre>
There are two interesting pieces that have been added, a URL with an anchor to another XMDP profile and a rev attribute. The rev value in
this example is 'extends'. These means that the page this is refering too, is extended by the property SELF. So you could make an XMDP that
lists all the possible rev attributes, 'extends', 'inverse', 'equivalent', etc. Then you could 'alias' one microformat property to another.

A universal XMDP validator/parser/etc could extract data across two or more XMDP profiles and potentially reason between them. This could create a small ontology.

It is not clear if this idea actually has utility or is simply a solution looking for a problem.

=== XMDP XML Schema ===
* [http://www.redantdesign.com/hcard/ XSD and XMDP for Microformats]
The link shows a bad example of creating XMDP from an XSD schema. The big question I guess is why?
Having XMDP defined in XSD should make it easier for machines to read Microformats, rules and strict data typing will allow Microformats to be validated when contained within an XML/XHTML document. If a document is using microformats with and XSD behind simple XPath queries can be used to harvest the information, this can then be rendered to straight XML for translation to RDF or other XML transport formats.

XSD behind XMDP also has distinct advantages for CMS authors, the XSD sitting behind xforms or sxforms to allow data entry into a CMS can be used to generate XMDP and valid Microformats when rendering content. This in theory should make it easier for CMS authors to develop a semantic core around data before exporting to XHTML + Microformats, RDF etc. and/or make data querying via web services a little more straightforward.

==== Follow up ====
Having looked into Microformats a little more I realise how bad that example is; however I still feel that placing a schema behind XMDP is a worthwhile exercise. I don't mind spending a little time on this if anyone feels it's a worthwhile exercise, but I'd propose the following:
* Define a loose set of microformat conventions (i.e. a meta property will be bound to an attribute etc.), and have these defined in a microformat namespace (mf:?).
* Create a XSD for common microformat fields without structures (dtStart etc.), with XSD typing and mf: rules (i.e. mf:optional-html-attribute-binding="title" or mf:html-attribute-binding="href" - names were never my strong point )
* Start working towards creating XSD schema including the common schema for agreed specifications

There would still need to be some form of link between the XMDP and the defining XSD (profile attribute or link element?). With these in place it should be possible for an application like tails, or new apps to pick up on any Microformat in a page and display the data, without the application having to be aware of the specific Microformat standard.

Microformats are cool, especially the fact that you don't have to be a rocket scientist to start using them. However if there can be a way of interleaving grassroots microformat adoption into the more complex semantic forms (RDF etc.), through XML then that's got to be a bonus?

[http://www.redantdesign.com/hcard/take2.asp more here]

== ID Attribute ==
<div class="discussion">
* A problem that I've had using XDMP is that it requires the use of the ID attribute (e.g. <dt id="foo">foo</dt>) to define the term "foo". As (X)HTML only allows one element with any given ID, this raises problems if you need to define the same term multiple times -- e.g. to define "category" as a class within both hcard and hcalendar, or to define "copyright" as both a class value and a rel value. [[User:TobyInk|TobyInk]] 06:26, 18 Feb 2008 (PST)
** Two things. First, "category" MUST NOT be different between hCard and hCalendar, and thus it is a feature, not a problem, that there can only be one id="category" between the two of them. Second, for the rel case, this is solved by using ID values prefixed with "rel-" for rel values. E.g. in http://gmpg.org/xmdp/1, rel-profile is defined with id="rel-profile", and the class name "profile" is defined with id="profile". [[User:Tantek|Tantek]] 17:48, 4 October 2009 (UTC)
</div>
== automatic parsability enabling ==

The current XMDP is useful for people to read and learn about a microformat, but of very limited utility to automate parsing microformats/[[poshformats]] (simply identification of vocabulary to parse for, and what attributes to parse for them). It would be nice if people could design their own poshformats, create an XMDP profile, and for the poshformat to be thus instantly parsable by machines. Here is the information that I think would need to be added to XMDP for this to be possible:

For each profile defined:

* What is/are the root class name(s) (as previous brainstormed above: [[xmdp-brainstorming#root_class_name_identification|root class name identification]]) of the microformats being defined by the XMDP (required)
* What are the properties of each microformat? Or alternatively (and preferably), which microformat(s) may a property be used with? (to handle the common and encouraged case of vocabulary re-use across microformats) (required)

For each property defined:

* A human-readable description of what the property means (XMDP already has this)
* Is it a class/rel/id (or rev, but deprecated) value (XMDP already has this)
* Is it singular or plural? (default: plural)
* What datatype is it? (e.g. text, URI, email, datetime, duration. default:text)
* Might it contain a nested poshformat/microformat? If so, then this profile should link to the profile of the nested poshformat /microformat. (Multiple formats could be defined in the same XMDP profile, using ID attributes to link from one to the other.)
* What nested subproperties might be found within it? Or alternatively (and preferably), whether a property is actually a subproperty, and if so, which properties may it be used inside? (again, to handle the common and encouraged case of vocabulary re-use) (Perhaps this could be indicated using a nested profile.)

We must expect that there will always be some parsing rules (e.g. hAtom's [http://microformats.org/wiki/hatom#Entry_Author "hunt the author" game]) which will not be expressible in a machine readable profile format, but it may be possible to cover 90% of the information a parser should need for most microformats.

Indeed experience has shown that any "real world" semantic markup languages that get significant use requires LOTS of special custom parsing rules (e.g. HTML is not fully parseable simply from the DTD, nor is RSS from the RSS DTD).

Thus while it may make sense to take incremental steps towards capturing more about a microformat in XMDP, full enabling of machine parsability should not be a short-term (nor even medium-term) goal, as others have tried (DTD, RelaxNG, XML Schema) and failed to achieve this.

== See Also ==
* [[xmdp]]
* [[xmdp-faq]]
* [[xmdp-issues]]

haudio

2014-12-10T13:58:08Z

Silinix: /* Purchase (Payment) */

<entry-title>hAudio 0.9.1</entry-title>
{{Template:DraftSpecification}}
{{TOC-right}}
http://farm2.static.flickr.com/1216/604867362_da0921136a_o.png

[[haudio|hAudio]] is a simple, open, distributed format, suitable for embedding information about audio recordings in (X)HTML, Atom, RSS, and arbitrary XML. hAudio is one of several [[microformats]] open standards. This page and Microformat is in the public domain.

== hAudio Microformat Draft Specification ==

=== Editors ===
* [[User:ManuSporny | Manu Sporny]] ([http://www.bitmunk.com/ Bitmunk] - [http://blog.digitalbazaar.com Digital Bazaar], Inc.)
* [[ user:WebOrganics | Martin McEvoy ]]
=== Authors ===
* [[User:ManuSporny | Manu Sporny]]
* [[ user:WebOrganics | Martin McEvoy ]]

=== Contributors===
[[User:ManuSporny | Manu Sporny]], [[ user:WebOrganics | Martin McEvoy ]], [[ User:AlexandreVandeSande | Alexandre Van De Sande ]], Michael Johnson, Dave Longley, Brian Suda, Ben Wiley Sittler, Scott Reynen, Frances Berriman, James Craig, David Janes, [[User:AndyMabbett|Andy Mabbett]], Danny Ayers, Rudy Desjardins, Edward O'Connor, Ryan King, Chris Griego, Brad Hafichuk, Tantek Çelik, Colin Barrett, Joe Andrieu, Michael Smethurst, [[User:ChrisNewell | Chris Newell]], Julian Stahnke, Justin Maxwell, Paul Wilkins and David I. Lehn.

Microformats [[#Copyright]] and [[#Patents]] statements apply.

== Introduction ==

It is difficult for a browser to extract semantic information about an audio recording described on a web page. Metadata such as speaker, musician, publisher, label, title of the work, release date, acquisition link, related image artwork and tags provide relevant context for the audio recording.

Having such information marked up can provide a number of benefits to the viewer. If a web browser understands that a particular web page contains a song performed by an artist, it can produce richer interactions. For example, specific searches may be performed for artists and songs via general search services such as Google and Wikipedia. Specific search services may also be queried such as MusicBrainz, The Internet Archive, FreeDB, or Bitmunk. Additionally, classification by crawlers can become more accurate. If there are 20 tracks found on a page done by the same artist, and that content consumes a significant portion of the page, it can be assumed that the page is not only about music, but also about a particular artist.

In order to enable and encourage the sharing, distribution, syndication, and aggregation of audio content, the authors propose the hAudio microformat, an open standard for distributed audio metadata. The authors have researched both numerous [[audio-info-examples]] in the wild and earlier attempts at [[audio-info-formats]], and have designed hAudio around a simple minimal schema for audio content. Feedback is encouraged on the [[haudio-feedback|hAudio feedback]] page.

=== Inspiration and Acknowledgments ===

Many thanks to the various individuals that did research and proposed ideas and discussion related to media info and audio info in general. Among the many participants are [[RodBegbie]], Dean Hudson, [http://tantek.com/log/ Tantek Çelik], [http://napsterization.org/stories/ Mary Hodder], [http://joshkinberg.com/blog/ Joshua Kinberg], ChrisMessina, and [http://onlisareinsradar.com/ Lisa Rein].

=== Scope ===

Audio content consistently share several common fields. Where possible hAudio has been based on this minimal common subset.

=== Out of scope ===

Fields that are type-specific have been omitted from hAudio. It is important that hAudio be kept simple and minimal from the start. Additional features can be added as deemed necessary by practical implementation experience.

The concept of a universal audio identifier, that is, how to identify the same audio album, song, speech, or podcast across different music and audio sites, though something very useful to have, is outside the scope of this format.

== Format ==

{{rfc-2119-intro}}

=== In General ===
The hAudio format is based on a set of fields common to numerous audio content sites and formats in use today on the web. Where possible field names have been chosen based on those defined by the related [[hcard|hCard]] standards.

=== Schema ===

The hAudio schema consists of the following:

* hAudio ('''<code>haudio</code>''')
** '''fn''' or/and '''album''' required. text.
** '''contributor'''. optional. using text or [[hCard]].
** '''duration'''. optional. ISO-8601 time duration. (re-used from [[hcalendar]]).
** '''item''' optional. using text or multiple properties from [[hAudio]].
** '''position''' optional. text.
** '''category'''. optional. text.
** '''published'''. optional.
** '''photo'''. optional. using any element containing a URL, such as IMG.
** '''description''' optional. text.
** '''sample''' (rel). optional. sample file/stream using [[rel-design-pattern]] with <code>sample</code> as the <code>mf-rel-value</code>.
** '''enclosure''' (rel). optional. full download of file using [[rel-enclosure]].
** '''payment''' (rel). optional. link to purchase process using [[rel-payment]].
** '''price''' optional. Using the sub properties '''currency''' and '''amount'''.

=== Field details ===

The fields of the hAudio schema represent the following:

==== hAudio ====

An hAudio is used to identify and describe metadata associated with an audio recording.

* an hAudio element is identified by class name <code>haudio</code>

==== fn ====

The name of a single audio recording is a short textual description used to identify the work among interested parties. This can be the name of a speech, song name, or short description regarding a sound effect.

* The element is identified by the class name <code>fn</code>.
* hAudio {{must}} have <code>fn</code> or/and <code>album</code>.

==== Album ====

The title of a collection of audio recordings, such as those that are represented as a CD, album or LP. The text should be a short textual description used to identify the work among interested parties.

* The element is identified by the class name <code>album</code>.
* hAudio {{must}} have either <code>album</code> or <code>fn</code> or both.

==== Item ====

A container for another hAudio item, which MUST be considered a part of the parent audio recording. An example of an item that is part of an hAudio would be a track in an audio album, a aria in an Opera, or a section of a podcast.

* The element is identified by the class name <code>item</code>.
* hAudio {{may}} have one or more items.
* The element {{must}} be processed opaquely. No sub-elements should be read from any hAudio contained in a track element.
* The contents of the element {{must}} be marked up using properties in hAudio.

==== Position ====

The position is used to describe the position of the hAudio item in a list. Examples of hAudio lists can include album track listings, music top 10 lists, playlists, and podcast chapters.

* The element is identified by the class name <code>position</code>.
* hAudio {{may}} include one <code>position</code> element.
* The contents of the element {{must}} be a number or other sequential identifier.
* The sequential identifier {{may}} be specified out-of-sequence.

==== Contributor ====

A Contributor is any entity that takes part in the creation and distribution of an audio recording. Examples include: artist, composer, publisher, guitarist, vocalist, violinist, lead singer, backup singer, bassist, drummer, manager, and roadie.

* The element is identified by the class name <code>contributor</code>.
* hAudio {{may}} include one or more contributors.
* The contributor's name SHOULD also be marked up as a valid hCard Microformat. [[hcard]]
*# The <code>role</code> attribute {{should}} be used to specify the contributor's responsibility related to the audio recording if hCard is utilized.
* The contributor's name {{may}} be specified in plain-text without being enclosed in a hCard Microformat.

==== Published ====

The published date specifies the date that the audio recording was made available to the public. Examples include: The airing date of a radio broadcast, the day a speech was given, or the day a music album was made available for sale.

* The element is identified by the class name <code>published</code>.
* hAudio {{may}} include one or more <code>published</code> elements.
* The contents of the element {{may}} include a date format compliant with the [[datetime-design-pattern]].

==== Sample ====

A Sample URI specifies from where an excerpt of the audio recording may be retrieved.

* The element is identified by a URI fitting the [[rel-design-pattern]], the rel content being <code>sample</code>.
* hAudio {{may}} include one or more URI <code>sample</code>s.
* The URI {{should}} point to a directly accessible stream or file.
* The type of the sample {{may}} be specified by using the <code>type</code> specifier for a URI.

==== Full Download (Enclosure) ====

A Full Download URI specifies from where the full version of an audio recording may be retrieved. The URI {{must}} point to a direct link to a file retrieval process (FTP, HTTP, BitTorrent URI, etc).

* The element is identified by a URI fitting the [[rel-design-pattern]], the rel content being <code>enclosure</code>.
* hAudio {{may}} include one or more <code>enclosure</code> URIs.
* The type of the file {{should}} be specified by using the <code>type</code> specifier for a URI.

==== Purchase (Payment) ====

A Purchase URI specifies from where the full version of an audio recording may be purchased. The URI {{must}} point to the beginning of a purchase process for the hAudio.

* The element is identified by a URI fitting the [[rel-design-pattern]], the rel content being <code>payment</code>.
* hAudio {{may}} include one or more <code>payment</code> URIs.[http://www.silinix.com silinix]
* The type of the file {{may}} be specified by using the <code>type</code> specifier for a URI.

==== Photo ====

A photo specifies an image that should be used to summarize the audio recording. Examples include: the image of a speaker, an audio album cover image, or a picture from a concert.

* The element is identified by the class name <code>photo</code>.
* hAudio {{may}} include one or more <code>photo</code> elements.
* The element {{should}} use an <img> element.
* The element {{may}} use any other element that contains a URL, such as <a> or <object>, but it is not recommended.

==== Category ====

The Category specifies the genre or style used to classify the audio recording. Examples include: blues, rock, motivational, spoken word, or sound effect.

* The element is identified by the class name <code>category</code>.
* hAudio {{may}} include one or more <code>category</code> elements.
* This element {{may}} be expressed using the [[rel-tag]] elemental microformat. When a category is expressed using rel-tag, the content of the element is used as the text for the category. For example: <code><a class="category" rel="tag" href="/tags/symphony">Symphonic</a></code> would have "Symphonic" as the text for the category.

==== Duration ====

The Duration specifies the length in time of the audio recording. Examples include: 104 seconds, 3:23, and 4 minutes.

* The element is identified by the class name <code>duration</code>.
* hAudio {{may}} include one <code>duration</code> element.
* The contents of the element {{may}} use the [[abbr-design-pattern]] whose title attribute contains an ISO-8601 formatted duration. An example of 3:23 (i.e 3 minutes 23 seconds) would be "PT3M23S" in ISO 8601 format.
* The element {{may}} contain the following sub properties:
** '''h''' Hour.
** '''min''' Minute.
** '''s''' Second.
Example:
<pre>
1:
3:
23
</pre>

==== Price ====

The Price specifies the amount of currency that must be exchanged for acquisition of a full specimen of the audio recording.

* The element is identified by the class name <code>price</code>.
* hAudio {{may}} include one or more <code>price</code> elements.
* The contents of the element {{may}} also use plain text with a currency symbol.
* The contents {{may}} contain the following sub properties:
** '''currency''' an [http://en.wikipedia.org/wiki/ISO_4217#Active_codes ISO 4217] currency name.
** '''amount''' a numerical value.
Example:
<pre>
<abbr class="currency" title="GBP">£</abbr>
4.99
</pre>

==== Description ====

An explanation of the contents of the hAudio item. This could explain the significance of a speech, the full-text description of a sound effect, or the meaning of a song or album.

* The element is identified by the class name <code>description</code>.
* hAudio {{may}} include one or more <code>description</code> elements. If more than one description element is defined, the full description for the hAudio is the concatenation, in order, of all <code>description</code> elements.

=== Parser Processing Notes ===

* It is important to understand that ITEM is an opaque element. When processing the ITEM element, none of the properties of the child hAudio should be pulled into the parent hAudio. However, it is recommended that child hAudio {{should}} inherit the following parent hAudio properties, if they are not specified on the child:
** album
** contributor
** category
** published
** photo

=== Semantic XHTML Design Principles ===

{{semantic-xhtml-design-principles}}

==== More Semantic Equivalents ====

For some properties there is a more semantic equivalent, and therefore they get special treatment, e.g.:

* For "photo", use <code><img class="photo" src="..." alt="" /></code>
* If only 'album' is specified, then the hAudio is an album.
* If only 'fn' is specified, then the hAudio is a song, audio track, sound effect, speech, or other atomic/singular work.
* If both 'album' and 'fn' are specified, then the hAudio is a atomic/singular work that is part of an album.
** Example: <code><nowiki>Side two of Meddle opens with One of These Days</nowiki></code>
* If 'fn' and one or more 'items's are specified, the hAudio is an audio recording containing multiple sections. Each item is assumed to be an hAudio that is part of the parent hAudio. None of the 'item' properties should implicitly be added to the containing hAudio. In other words, the parser shouldn't parse the contents of the 'item' into the higher-level hAudio object.

==== Language ====

* To explicitly convey the natural language that an hAudio is written in, use the standard (X)HTML 'lang' or 'xml:lang' attribute on the element with class="haudio"
**e.g. <code><nowiki>I like Das Lied von der Erde best.</nowiki></code>
*If portions of an hAudio (e.g. the item name) are in a different language to the rest of the hAudio, use the 'lang' or 'xml:lang' attribute on those portions.
* hAudio parsers which need to handle the native language of hAudio {{must}} process the standard (X)HTML 'lang' or 'xml:lang' attribute as specified.
* hAudio parsers which need to handle native language {{may}} traverse up the DOM to discover the native language of the page and apply that to the hAudio if no other language is specified on the hAudio.

==== Human vs. Machine Readable ====

If an <code><abbr></code> element is used for a property, then its '<code>title</code>' attribute is used for the value of the property, instead of the contents of the element, which can then be used to provide a user-friendly alternate presentation of the value.

If an <code><a></code> element is used for one or more properties, it {{must}} be treated as follows:
# For the 'photo' property and any other property that takes a URL as its value, the <code>href="..."</code> attribute provides the property value.
# For other properties, the element's content is the value of the property.

If an <code><img></code> element is used for one or more properties, it {{must}} be treated as follows:
# For the 'photo' property and any other property that takes a URL as its value, the <code>src="..."</code> attribute provides the property value.
# For other properties, the <code><img></code> element's '<code>alt</code>' attribute is the value of the property.

If an <code><object></code> element is used for one or more properties, it {{must}} be treated as follows:
# For the 'photo' property and any other property that takes a URL as its value, the <code>data="..."</code> attribute provides the property value.
# For other properties, the element's content is the value of the property.

=== Notes ===

This section is informative.

* By marking up audio content with the hAudio microformat, the expectation is communicated that information about the content {{may}} be indexed. This has no impact on the copyright of the content itself which the publisher may explicitly specify using the [[rel-license]] microformat.

== XMDP Profile ==
See: [[haudio-profile]].

== Examples ==

This section is informative.

Here are a few examples of text about, and links to, audio content, from real web sites, showing how they could be easily enhanced to use hAudio.



=== Simple Song Example ===

Display:

(This is a live example, detectable in parsers)

<div class="haudio">
Start Wearing Purple by Gogol Bordello
</div>

Microformatted XHTML:

<pre>
<div class="haudio">
Start Wearing Purple by
Gogol Bordello
</div>
</pre>

=== Speech Example ===

(This is a live example, detectable in parsers)

Display:

<div class="haudio">
I Have a Dream, a speech by Martin Luther King, Jr.
</div>

Microformatted XHTML:
<pre>
<div class="haudio">
I Have a Dream, a
speech by



Martin
Luther
King,
Jr.



</div>
</pre>

Note the use of [[hcard|hCard]].

=== Song and Album Example ===

(This is a live example, detectable in parsers)

Display:

<div class="haudio">
Start Wearing Purple by Gogol Bordello found on Underdog World Strike
</div>

Microformatted XHTML:

<pre>
<div class="haudio">
Start Wearing Purple by


Gogol Bordello


found on
Underdog World Strike
</div>
</pre>

Note that for bands, hCard's ''[[hcard#Implied_.22organization-name.22_Optimization|Implied "organization-name" Optimization]]'' is used.

=== Complete Album Example ===

An example that uses every element of hAudio:

[Image] Live Phish, Volume 15 by Phish 
Released: October 31, 2002 
Acquire: Sample, Live Recording, Buy High Quality Track 
Category: [http://www.example.org/tags/live live] 
Duration: 145 minutes, 27 seconds 
Price: $14.99 
 
Tracks: 
1. Sanity (5:48) 
2. Highway To Hell (3:39)

Here is the hAudio Microformat markup:

<pre>
<div class="haudio">
<img class="photo" src="images/live_phish_vol_15.jpg" alt="" />
Live Phish, Volume 15


Phish


 
Released on:
<abbr class="published" title="2002-10-31">October 31, 2002</abbr>
 
Acquire:
<a rel="sample" href="/samples/live_phish_vol_15_sample.mp3">Sample</a>,
<a rel="enclosure" href="/live/phish_live_phish_vol_15.mp3">Live Recording</a>,
<a rel="payment" href="/buy/phish_live_phish_vol_15">Buy High Quality Track</a>
Category: <a class="category" rel="tag" href="http://www.example.org/tags/live">live</a>
Duration: <abbr class="duration" title="PT145M27S">145 minutes, 27 seconds</abbr>
Price: <div class="price"><abbr class="currency" title="USD">$</abbr>14.99</div>
Tracks:
<div class="item">
1.
Sanity
(<abbr class="duration" title="PT5M48S">5:48</abbr>)
</div>
<div class="item">
2.
Highway To Hell
(<abbr class="duration" title="PT3M39S">3:39</abbr>)
</div>
</div>
</pre>

=== Multi-part Podcast Example ===

DigitalPlanet Podcast: 29 Oct 07

Forensic computing: is it really possible to delete data from your machine? Grand plans for getting broadband into Africa, checking out the sky at night via the internet and answering your emails to the programme.

Download MP3

<pre>
<div class="haudio">

DigitalPlanet Podcast
:
<abbr class="published" title="20071029">29 Oct 07</abbr>


<div class="item">
Forensic computing: is it really possible to delete data from your machine?
</div>
<div class="item">
Grand plans for getting broadband into Africa
</div>
,
<div class="item">
checking out the sky at night via the internet
</div>
and
<div class="item">
answering your emails
</div>
to the programme.


<a rel="enclosure" href="/download/episode/DigitalPlanet-2007-10-29">Download MP3</a>

</div>
</pre>

=== Opera Example ===

(This is a live example, detectable in parsers)

<div class="haudio" lang="en">
La Bohème is an opera in four acts by Giacomo Puccini to an Italian liberetto by Luigi Illica and Giuseppe Giacosais. I saw it performed last week and found Act III to be pretty interesting, especially the "Sa dirmi, scusi" and "O buon Marcello, aiuto!" arias.
</div>

<pre>
<div class="haudio" lang="en">
La Bohème
is an
opera
in four acts by
Giacomo Puccini
to an
Italian liberetto
by
Luigi Illica
and
Giuseppe Giacosais.
I saw it performed last week and found

Act III
to be pretty interesting, especially the

"Sa dirmi, scusi"

and

"O buon Marcello, aiuto!"

arias.

</div>
</pre>

== Examples in the wild ==

This section is '''informative'''.

* [http://en.wikipedia.org/wiki/Category:Articles_with_hAudio_microformats Wikipedia] has 119,555 songs and albums marked up in hAudio format.
* [http://weborganics.co.uk/haudio-rss/ hAudio-RSS] uses hAudio 0.9.1 and XSLT to generate an RSS2 Playlist.
* Tara Hunt of [http://openmediaweb.org/index.php/2008/01/13/publishing-my-workout-music-in-haudio/ Open Media Web] Published her workout Music in hAudio
* Grabb.it The web music player now uses hAudio 0.9 in its [http://grabb.it/users/greg user pages]
* [http://soundcloud.com/ SoundCloud] has hAudio in its pages.
* [http://populizer.com/ Populizer] also has hAudio in its pages.
* The [http://www.numblog.de/ New Urban Music Blog] has hAudio marked up in its pages.
* [http://alpha.libre.fm/ Libre.fm] has marked up on all its user pages in hAudio see : [http://alpha.libre.fm/user/weborganics example]

== Implementations ==

This section is '''informative'''.

*[http://weborganics.co.uk/files/js/haudio.js hAudio 0.9 script] for [[operator|Operator]], updated version of the original hAudio script by David Lehn.
* Matthias Pfefferle has made some [http://notizblog.org/projects/haudio-icons/ hAudio Icons]
* [http://microform.at/ Microformat TransFormr] extracts hAudio 0.9.1 as a RSS2 Podcast.
* [http://buzzword.org.uk/cognition/ Cognition] 0.1-α11 and above will parse hAudio 0.9 and export as RDF/XML or RDF/JSON. As of 0.1-α12, it will also export in M3U playlist format and Turtle.
* [http://weborganics.co.uk/mo-haudio/ hAudio Microformat to RDF Music Ontology], a [http://www.w3.org/TR/grddl/ GRDDL] profile for hAudio 0.9.1, producing [http://musicontology.com/ Music Ontology] RDF.
* The [http://singpolyma.net/plugins/actionstream/ wp-diso-actionstream] plugin produces hAudio for last.fm scrobbles
*...


== References ==
=== Normative References ===
* [http://www.w3.org/TR/2002/REC-xhtml1-20020801/ XHTML 1.0 SE]
* [http://gmpg.org/xmdp/ XMDP]
* [[hcard|hCard]]
* [[abbr-design-pattern]]
* [[currency-proposal]]
* [[datetime-design-pattern]]
* [[rel-design-pattern]]
* [[ISO-31-1|ISO-31-1/ISQ]]

=== Informative References ===
* [http://www.w3.org/TR/REC-CSS1 CSS1]
* ISO.8601.1988
** International Organization for Standardization, "Data elements and interchange formats - Information interchange - Representation of dates and times", ISO Standard 8601, June 1988.
* [http://www.w3.org/TR/1998/NOTE-datetime-19980827 W3C NOTE-datetime-19980827]
* [http://www.w3.org/Consortium/Patent-Policy-20040205/ W3C Patent Policy]
* Other audio metadata efforts. See [[audio-info-formats]].

==== Similar Work ====
* [[media-info]]
* [[grouping-examples]]
* [[grouping-brainstorming]]
* [[xoxo|XOXO]]

=== Copyright ===

This document and hAudio specification was placed into the public domain on 2008-11-14 by the authors. There are no usage, distribution, re-printing, or any other restrictions of any kind with regards to the text or content of this specification.

=== Patents ===

{{MicroFormatPatentStatement}}

=== Public Domain Release ===

The authors and editors of this page due hereby relinquish their copyright on the document and release the text of this page into the public domain.

* Manu Sporny - Signature /Manu Sporny/
* Alexandre Van de Sande
* [[User:WebOrganics|Martin McEvoy]]
* [[User:DavidLehn|David Lehn]] - Signature /David Lehn/
* [[User:AndyMabbett|Andy Mabbett]]

== Work in progress ==
This specification is a work in progress. As additional aspects are discussed, understood, and written, they will be added.

== Related Pages ==
{{haudio-related-pages}}
* [[audio]] (other pages about Audio on this wiki)

[[Category:Draft Specifications]]

haudio

2014-12-10T13:57:36Z

Silinix: /* Purchase (Payment) */

<entry-title>hAudio 0.9.1</entry-title>
{{Template:DraftSpecification}}
{{TOC-right}}
http://farm2.static.flickr.com/1216/604867362_da0921136a_o.png

[[haudio|hAudio]] is a simple, open, distributed format, suitable for embedding information about audio recordings in (X)HTML, Atom, RSS, and arbitrary XML. hAudio is one of several [[microformats]] open standards. This page and Microformat is in the public domain.

== hAudio Microformat Draft Specification ==

=== Editors ===
* [[User:ManuSporny | Manu Sporny]] ([http://www.bitmunk.com/ Bitmunk] - [http://blog.digitalbazaar.com Digital Bazaar], Inc.)
* [[ user:WebOrganics | Martin McEvoy ]]
=== Authors ===
* [[User:ManuSporny | Manu Sporny]]
* [[ user:WebOrganics | Martin McEvoy ]]

=== Contributors===
[[User:ManuSporny | Manu Sporny]], [[ user:WebOrganics | Martin McEvoy ]], [[ User:AlexandreVandeSande | Alexandre Van De Sande ]], Michael Johnson, Dave Longley, Brian Suda, Ben Wiley Sittler, Scott Reynen, Frances Berriman, James Craig, David Janes, [[User:AndyMabbett|Andy Mabbett]], Danny Ayers, Rudy Desjardins, Edward O'Connor, Ryan King, Chris Griego, Brad Hafichuk, Tantek Çelik, Colin Barrett, Joe Andrieu, Michael Smethurst, [[User:ChrisNewell | Chris Newell]], Julian Stahnke, Justin Maxwell, Paul Wilkins and David I. Lehn.

Microformats [[#Copyright]] and [[#Patents]] statements apply.

== Introduction ==

It is difficult for a browser to extract semantic information about an audio recording described on a web page. Metadata such as speaker, musician, publisher, label, title of the work, release date, acquisition link, related image artwork and tags provide relevant context for the audio recording.

Having such information marked up can provide a number of benefits to the viewer. If a web browser understands that a particular web page contains a song performed by an artist, it can produce richer interactions. For example, specific searches may be performed for artists and songs via general search services such as Google and Wikipedia. Specific search services may also be queried such as MusicBrainz, The Internet Archive, FreeDB, or Bitmunk. Additionally, classification by crawlers can become more accurate. If there are 20 tracks found on a page done by the same artist, and that content consumes a significant portion of the page, it can be assumed that the page is not only about music, but also about a particular artist.

In order to enable and encourage the sharing, distribution, syndication, and aggregation of audio content, the authors propose the hAudio microformat, an open standard for distributed audio metadata. The authors have researched both numerous [[audio-info-examples]] in the wild and earlier attempts at [[audio-info-formats]], and have designed hAudio around a simple minimal schema for audio content. Feedback is encouraged on the [[haudio-feedback|hAudio feedback]] page.

=== Inspiration and Acknowledgments ===

Many thanks to the various individuals that did research and proposed ideas and discussion related to media info and audio info in general. Among the many participants are [[RodBegbie]], Dean Hudson, [http://tantek.com/log/ Tantek Çelik], [http://napsterization.org/stories/ Mary Hodder], [http://joshkinberg.com/blog/ Joshua Kinberg], ChrisMessina, and [http://onlisareinsradar.com/ Lisa Rein].

=== Scope ===

Audio content consistently share several common fields. Where possible hAudio has been based on this minimal common subset.

=== Out of scope ===

Fields that are type-specific have been omitted from hAudio. It is important that hAudio be kept simple and minimal from the start. Additional features can be added as deemed necessary by practical implementation experience.

The concept of a universal audio identifier, that is, how to identify the same audio album, song, speech, or podcast across different music and audio sites, though something very useful to have, is outside the scope of this format.

== Format ==

{{rfc-2119-intro}}

=== In General ===
The hAudio format is based on a set of fields common to numerous audio content sites and formats in use today on the web. Where possible field names have been chosen based on those defined by the related [[hcard|hCard]] standards.

=== Schema ===

The hAudio schema consists of the following:

* hAudio ('''<code>haudio</code>''')
** '''fn''' or/and '''album''' required. text.
** '''contributor'''. optional. using text or [[hCard]].
** '''duration'''. optional. ISO-8601 time duration. (re-used from [[hcalendar]]).
** '''item''' optional. using text or multiple properties from [[hAudio]].
** '''position''' optional. text.
** '''category'''. optional. text.
** '''published'''. optional.
** '''photo'''. optional. using any element containing a URL, such as IMG.
** '''description''' optional. text.
** '''sample''' (rel). optional. sample file/stream using [[rel-design-pattern]] with <code>sample</code> as the <code>mf-rel-value</code>.
** '''enclosure''' (rel). optional. full download of file using [[rel-enclosure]].
** '''payment''' (rel). optional. link to purchase process using [[rel-payment]].
** '''price''' optional. Using the sub properties '''currency''' and '''amount'''.

=== Field details ===

The fields of the hAudio schema represent the following:

==== hAudio ====

An hAudio is used to identify and describe metadata associated with an audio recording.

* an hAudio element is identified by class name <code>haudio</code>

==== fn ====

The name of a single audio recording is a short textual description used to identify the work among interested parties. This can be the name of a speech, song name, or short description regarding a sound effect.

* The element is identified by the class name <code>fn</code>.
* hAudio {{must}} have <code>fn</code> or/and <code>album</code>.

==== Album ====

The title of a collection of audio recordings, such as those that are represented as a CD, album or LP. The text should be a short textual description used to identify the work among interested parties.

* The element is identified by the class name <code>album</code>.
* hAudio {{must}} have either <code>album</code> or <code>fn</code> or both.

==== Item ====

A container for another hAudio item, which MUST be considered a part of the parent audio recording. An example of an item that is part of an hAudio would be a track in an audio album, a aria in an Opera, or a section of a podcast.

* The element is identified by the class name <code>item</code>.
* hAudio {{may}} have one or more items.
* The element {{must}} be processed opaquely. No sub-elements should be read from any hAudio contained in a track element.
* The contents of the element {{must}} be marked up using properties in hAudio.

==== Position ====

The position is used to describe the position of the hAudio item in a list. Examples of hAudio lists can include album track listings, music top 10 lists, playlists, and podcast chapters.

* The element is identified by the class name <code>position</code>.
* hAudio {{may}} include one <code>position</code> element.
* The contents of the element {{must}} be a number or other sequential identifier.
* The sequential identifier {{may}} be specified out-of-sequence.

==== Contributor ====

A Contributor is any entity that takes part in the creation and distribution of an audio recording. Examples include: artist, composer, publisher, guitarist, vocalist, violinist, lead singer, backup singer, bassist, drummer, manager, and roadie.

* The element is identified by the class name <code>contributor</code>.
* hAudio {{may}} include one or more contributors.
* The contributor's name SHOULD also be marked up as a valid hCard Microformat. [[hcard]]
*# The <code>role</code> attribute {{should}} be used to specify the contributor's responsibility related to the audio recording if hCard is utilized.
* The contributor's name {{may}} be specified in plain-text without being enclosed in a hCard Microformat.

==== Published ====

The published date specifies the date that the audio recording was made available to the public. Examples include: The airing date of a radio broadcast, the day a speech was given, or the day a music album was made available for sale.

* The element is identified by the class name <code>published</code>.
* hAudio {{may}} include one or more <code>published</code> elements.
* The contents of the element {{may}} include a date format compliant with the [[datetime-design-pattern]].

==== Sample ====

A Sample URI specifies from where an excerpt of the audio recording may be retrieved.

* The element is identified by a URI fitting the [[rel-design-pattern]], the rel content being <code>sample</code>.
* hAudio {{may}} include one or more URI <code>sample</code>s.
* The URI {{should}} point to a directly accessible stream or file.
* The type of the sample {{may}} be specified by using the <code>type</code> specifier for a URI.

==== Full Download (Enclosure) ====

A Full Download URI specifies from where the full version of an audio recording may be retrieved. The URI {{must}} point to a direct link to a file retrieval process (FTP, HTTP, BitTorrent URI, etc).

* The element is identified by a URI fitting the [[rel-design-pattern]], the rel content being <code>enclosure</code>.
* hAudio {{may}} include one or more <code>enclosure</code> URIs.
* The type of the file {{should}} be specified by using the <code>type</code> specifier for a URI.

==== Purchase (Payment) ====

A Purchase URI specifies from where the full version of an audio recording may be purchased. The URI {{must}} point to the beginning of a purchase process for the hAudio.

* The element is identified by a URI fitting the [[rel-design-pattern]], the rel content being <code>payment</code>.
* hAudio {{may}} include one or more <code>payment</code> URIs.[http://www.silinix.com silinix title]
* The type of the file {{may}} be specified by using the <code>type</code> specifier for a URI.

==== Photo ====

A photo specifies an image that should be used to summarize the audio recording. Examples include: the image of a speaker, an audio album cover image, or a picture from a concert.

* The element is identified by the class name <code>photo</code>.
* hAudio {{may}} include one or more <code>photo</code> elements.
* The element {{should}} use an <img> element.
* The element {{may}} use any other element that contains a URL, such as <a> or <object>, but it is not recommended.

==== Category ====

The Category specifies the genre or style used to classify the audio recording. Examples include: blues, rock, motivational, spoken word, or sound effect.

* The element is identified by the class name <code>category</code>.
* hAudio {{may}} include one or more <code>category</code> elements.
* This element {{may}} be expressed using the [[rel-tag]] elemental microformat. When a category is expressed using rel-tag, the content of the element is used as the text for the category. For example: <code><a class="category" rel="tag" href="/tags/symphony">Symphonic</a></code> would have "Symphonic" as the text for the category.

==== Duration ====

The Duration specifies the length in time of the audio recording. Examples include: 104 seconds, 3:23, and 4 minutes.

* The element is identified by the class name <code>duration</code>.
* hAudio {{may}} include one <code>duration</code> element.
* The contents of the element {{may}} use the [[abbr-design-pattern]] whose title attribute contains an ISO-8601 formatted duration. An example of 3:23 (i.e 3 minutes 23 seconds) would be "PT3M23S" in ISO 8601 format.
* The element {{may}} contain the following sub properties:
** '''h''' Hour.
** '''min''' Minute.
** '''s''' Second.
Example:
<pre>
1:
3:
23
</pre>

==== Price ====

The Price specifies the amount of currency that must be exchanged for acquisition of a full specimen of the audio recording.

* The element is identified by the class name <code>price</code>.
* hAudio {{may}} include one or more <code>price</code> elements.
* The contents of the element {{may}} also use plain text with a currency symbol.
* The contents {{may}} contain the following sub properties:
** '''currency''' an [http://en.wikipedia.org/wiki/ISO_4217#Active_codes ISO 4217] currency name.
** '''amount''' a numerical value.
Example:
<pre>
<abbr class="currency" title="GBP">£</abbr>
4.99
</pre>

==== Description ====

An explanation of the contents of the hAudio item. This could explain the significance of a speech, the full-text description of a sound effect, or the meaning of a song or album.

* The element is identified by the class name <code>description</code>.
* hAudio {{may}} include one or more <code>description</code> elements. If more than one description element is defined, the full description for the hAudio is the concatenation, in order, of all <code>description</code> elements.

=== Parser Processing Notes ===

* It is important to understand that ITEM is an opaque element. When processing the ITEM element, none of the properties of the child hAudio should be pulled into the parent hAudio. However, it is recommended that child hAudio {{should}} inherit the following parent hAudio properties, if they are not specified on the child:
** album
** contributor
** category
** published
** photo

=== Semantic XHTML Design Principles ===

{{semantic-xhtml-design-principles}}

==== More Semantic Equivalents ====

For some properties there is a more semantic equivalent, and therefore they get special treatment, e.g.:

* For "photo", use <code><img class="photo" src="..." alt="" /></code>
* If only 'album' is specified, then the hAudio is an album.
* If only 'fn' is specified, then the hAudio is a song, audio track, sound effect, speech, or other atomic/singular work.
* If both 'album' and 'fn' are specified, then the hAudio is a atomic/singular work that is part of an album.
** Example: <code><nowiki>Side two of Meddle opens with One of These Days</nowiki></code>
* If 'fn' and one or more 'items's are specified, the hAudio is an audio recording containing multiple sections. Each item is assumed to be an hAudio that is part of the parent hAudio. None of the 'item' properties should implicitly be added to the containing hAudio. In other words, the parser shouldn't parse the contents of the 'item' into the higher-level hAudio object.

==== Language ====

* To explicitly convey the natural language that an hAudio is written in, use the standard (X)HTML 'lang' or 'xml:lang' attribute on the element with class="haudio"
**e.g. <code><nowiki>I like Das Lied von der Erde best.</nowiki></code>
*If portions of an hAudio (e.g. the item name) are in a different language to the rest of the hAudio, use the 'lang' or 'xml:lang' attribute on those portions.
* hAudio parsers which need to handle the native language of hAudio {{must}} process the standard (X)HTML 'lang' or 'xml:lang' attribute as specified.
* hAudio parsers which need to handle native language {{may}} traverse up the DOM to discover the native language of the page and apply that to the hAudio if no other language is specified on the hAudio.

==== Human vs. Machine Readable ====

If an <code><abbr></code> element is used for a property, then its '<code>title</code>' attribute is used for the value of the property, instead of the contents of the element, which can then be used to provide a user-friendly alternate presentation of the value.

If an <code><a></code> element is used for one or more properties, it {{must}} be treated as follows:
# For the 'photo' property and any other property that takes a URL as its value, the <code>href="..."</code> attribute provides the property value.
# For other properties, the element's content is the value of the property.

If an <code><img></code> element is used for one or more properties, it {{must}} be treated as follows:
# For the 'photo' property and any other property that takes a URL as its value, the <code>src="..."</code> attribute provides the property value.
# For other properties, the <code><img></code> element's '<code>alt</code>' attribute is the value of the property.

If an <code><object></code> element is used for one or more properties, it {{must}} be treated as follows:
# For the 'photo' property and any other property that takes a URL as its value, the <code>data="..."</code> attribute provides the property value.
# For other properties, the element's content is the value of the property.

=== Notes ===

This section is informative.

* By marking up audio content with the hAudio microformat, the expectation is communicated that information about the content {{may}} be indexed. This has no impact on the copyright of the content itself which the publisher may explicitly specify using the [[rel-license]] microformat.

== XMDP Profile ==
See: [[haudio-profile]].

== Examples ==

This section is informative.

Here are a few examples of text about, and links to, audio content, from real web sites, showing how they could be easily enhanced to use hAudio.



=== Simple Song Example ===

Display:

(This is a live example, detectable in parsers)

<div class="haudio">
Start Wearing Purple by Gogol Bordello
</div>

Microformatted XHTML:

<pre>
<div class="haudio">
Start Wearing Purple by
Gogol Bordello
</div>
</pre>

=== Speech Example ===

(This is a live example, detectable in parsers)

Display:

<div class="haudio">
I Have a Dream, a speech by Martin Luther King, Jr.
</div>

Microformatted XHTML:
<pre>
<div class="haudio">
I Have a Dream, a
speech by



Martin
Luther
King,
Jr.



</div>
</pre>

Note the use of [[hcard|hCard]].

=== Song and Album Example ===

(This is a live example, detectable in parsers)

Display:

<div class="haudio">
Start Wearing Purple by Gogol Bordello found on Underdog World Strike
</div>

Microformatted XHTML:

<pre>
<div class="haudio">
Start Wearing Purple by


Gogol Bordello


found on
Underdog World Strike
</div>
</pre>

Note that for bands, hCard's ''[[hcard#Implied_.22organization-name.22_Optimization|Implied "organization-name" Optimization]]'' is used.

=== Complete Album Example ===

An example that uses every element of hAudio:

[Image] Live Phish, Volume 15 by Phish 
Released: October 31, 2002 
Acquire: Sample, Live Recording, Buy High Quality Track 
Category: [http://www.example.org/tags/live live] 
Duration: 145 minutes, 27 seconds 
Price: $14.99 
 
Tracks: 
1. Sanity (5:48) 
2. Highway To Hell (3:39)

Here is the hAudio Microformat markup:

<pre>
<div class="haudio">
<img class="photo" src="images/live_phish_vol_15.jpg" alt="" />
Live Phish, Volume 15


Phish


 
Released on:
<abbr class="published" title="2002-10-31">October 31, 2002</abbr>
 
Acquire:
<a rel="sample" href="/samples/live_phish_vol_15_sample.mp3">Sample</a>,
<a rel="enclosure" href="/live/phish_live_phish_vol_15.mp3">Live Recording</a>,
<a rel="payment" href="/buy/phish_live_phish_vol_15">Buy High Quality Track</a>
Category: <a class="category" rel="tag" href="http://www.example.org/tags/live">live</a>
Duration: <abbr class="duration" title="PT145M27S">145 minutes, 27 seconds</abbr>
Price: <div class="price"><abbr class="currency" title="USD">$</abbr>14.99</div>
Tracks:
<div class="item">
1.
Sanity
(<abbr class="duration" title="PT5M48S">5:48</abbr>)
</div>
<div class="item">
2.
Highway To Hell
(<abbr class="duration" title="PT3M39S">3:39</abbr>)
</div>
</div>
</pre>

=== Multi-part Podcast Example ===

DigitalPlanet Podcast: 29 Oct 07

Forensic computing: is it really possible to delete data from your machine? Grand plans for getting broadband into Africa, checking out the sky at night via the internet and answering your emails to the programme.

Download MP3

<pre>
<div class="haudio">

DigitalPlanet Podcast
:
<abbr class="published" title="20071029">29 Oct 07</abbr>


<div class="item">
Forensic computing: is it really possible to delete data from your machine?
</div>
<div class="item">
Grand plans for getting broadband into Africa
</div>
,
<div class="item">
checking out the sky at night via the internet
</div>
and
<div class="item">
answering your emails
</div>
to the programme.


<a rel="enclosure" href="/download/episode/DigitalPlanet-2007-10-29">Download MP3</a>

</div>
</pre>

=== Opera Example ===

(This is a live example, detectable in parsers)

<div class="haudio" lang="en">
La Bohème is an opera in four acts by Giacomo Puccini to an Italian liberetto by Luigi Illica and Giuseppe Giacosais. I saw it performed last week and found Act III to be pretty interesting, especially the "Sa dirmi, scusi" and "O buon Marcello, aiuto!" arias.
</div>

<pre>
<div class="haudio" lang="en">
La Bohème
is an
opera
in four acts by
Giacomo Puccini
to an
Italian liberetto
by
Luigi Illica
and
Giuseppe Giacosais.
I saw it performed last week and found

Act III
to be pretty interesting, especially the

"Sa dirmi, scusi"

and

"O buon Marcello, aiuto!"

arias.

</div>
</pre>

== Examples in the wild ==

This section is '''informative'''.

* [http://en.wikipedia.org/wiki/Category:Articles_with_hAudio_microformats Wikipedia] has 119,555 songs and albums marked up in hAudio format.
* [http://weborganics.co.uk/haudio-rss/ hAudio-RSS] uses hAudio 0.9.1 and XSLT to generate an RSS2 Playlist.
* Tara Hunt of [http://openmediaweb.org/index.php/2008/01/13/publishing-my-workout-music-in-haudio/ Open Media Web] Published her workout Music in hAudio
* Grabb.it The web music player now uses hAudio 0.9 in its [http://grabb.it/users/greg user pages]
* [http://soundcloud.com/ SoundCloud] has hAudio in its pages.
* [http://populizer.com/ Populizer] also has hAudio in its pages.
* The [http://www.numblog.de/ New Urban Music Blog] has hAudio marked up in its pages.
* [http://alpha.libre.fm/ Libre.fm] has marked up on all its user pages in hAudio see : [http://alpha.libre.fm/user/weborganics example]

== Implementations ==

This section is '''informative'''.

*[http://weborganics.co.uk/files/js/haudio.js hAudio 0.9 script] for [[operator|Operator]], updated version of the original hAudio script by David Lehn.
* Matthias Pfefferle has made some [http://notizblog.org/projects/haudio-icons/ hAudio Icons]
* [http://microform.at/ Microformat TransFormr] extracts hAudio 0.9.1 as a RSS2 Podcast.
* [http://buzzword.org.uk/cognition/ Cognition] 0.1-α11 and above will parse hAudio 0.9 and export as RDF/XML or RDF/JSON. As of 0.1-α12, it will also export in M3U playlist format and Turtle.
* [http://weborganics.co.uk/mo-haudio/ hAudio Microformat to RDF Music Ontology], a [http://www.w3.org/TR/grddl/ GRDDL] profile for hAudio 0.9.1, producing [http://musicontology.com/ Music Ontology] RDF.
* The [http://singpolyma.net/plugins/actionstream/ wp-diso-actionstream] plugin produces hAudio for last.fm scrobbles
*...


== References ==
=== Normative References ===
* [http://www.w3.org/TR/2002/REC-xhtml1-20020801/ XHTML 1.0 SE]
* [http://gmpg.org/xmdp/ XMDP]
* [[hcard|hCard]]
* [[abbr-design-pattern]]
* [[currency-proposal]]
* [[datetime-design-pattern]]
* [[rel-design-pattern]]
* [[ISO-31-1|ISO-31-1/ISQ]]

=== Informative References ===
* [http://www.w3.org/TR/REC-CSS1 CSS1]
* ISO.8601.1988
** International Organization for Standardization, "Data elements and interchange formats - Information interchange - Representation of dates and times", ISO Standard 8601, June 1988.
* [http://www.w3.org/TR/1998/NOTE-datetime-19980827 W3C NOTE-datetime-19980827]
* [http://www.w3.org/Consortium/Patent-Policy-20040205/ W3C Patent Policy]
* Other audio metadata efforts. See [[audio-info-formats]].

==== Similar Work ====
* [[media-info]]
* [[grouping-examples]]
* [[grouping-brainstorming]]
* [[xoxo|XOXO]]

=== Copyright ===

This document and hAudio specification was placed into the public domain on 2008-11-14 by the authors. There are no usage, distribution, re-printing, or any other restrictions of any kind with regards to the text or content of this specification.

=== Patents ===

{{MicroFormatPatentStatement}}

=== Public Domain Release ===

The authors and editors of this page due hereby relinquish their copyright on the document and release the text of this page into the public domain.

* Manu Sporny - Signature /Manu Sporny/
* Alexandre Van de Sande
* [[User:WebOrganics|Martin McEvoy]]
* [[User:DavidLehn|David Lehn]] - Signature /David Lehn/
* [[User:AndyMabbett|Andy Mabbett]]

== Work in progress ==
This specification is a work in progress. As additional aspects are discussed, understood, and written, they will be added.

== Related Pages ==
{{haudio-related-pages}}
* [[audio]] (other pages about Audio on this wiki)

[[Category:Draft Specifications]]