Commonwealth Scientific and Industrial Research Organisation CSIRO, Australia

Locked Bag 17 North Ryde NSW 2113 Australia +61 2 9325 3141 Silvia.Pfeiffer@csiro.au http://www.cmis.csiro.au/Silvia.Pfeiffer/

Commonwealth Scientific and Industrial Research Organisation CSIRO, Australia

Locked Bag 17 North Ryde NSW 2113 Australia +61 2 9325 3133 Conrad.Parker@csiro.au http://www.cmis.csiro.au/Conrad.Parker/

This specification defines the Continuous Media Markup Language (CMML), version 1.0, an XML-based markup language for time-continuous data. It is a sister document to the specification of the ANNODEX(TM) annotation and indexing format for time-continuous data. The CMML is an authoring language for annotating, indexing and hyperlinking time-continuous data in the ANNODEX(TM) format. Its tags provide for the creation of structured and unstructured annotations as well as hyperlinks and addressable named anchor points for fragments of time-continuous data. The tag names in use in CMML are similar to the ones in XHTML. At this point in time, the right to produce derivative works is not granted to the IETF as the authors are uncertain about the necessity to create a working group. The specification is not encumbered by patents. The ANNODEX(TM) format is protected by a trademark to prevent the use of the term "annodex" for any related but non-conformant and therefore non-interoperable technology.

Please note that this document assumes that the reader has a fluent working knowledge of XML, HTML, XHTML and the World Wide Web. Knowledge about the ANNODEX(TM) sister document is also presumed. Time-continuous data in the ANNODEX(TM) format contains XML-based annotations and hyperlinking information that enables it to be browsed by client applications, and crawled and indexed by search engines. The Continuous Media Markup Language CMML is a simple markup language for authoring the XML data to be multiplexed with the time-continuous data given in binary bitstreams. This process eventually creates ANNODEX(TM) format bitstreams. The CMML has much in common with XHTML. The CMML can describe one or several time-continuous media bitstreams. It is used to create all the tags required for authoring the annotation information for the ANNODEX(TM) format. It therefore basically contains the same tags as the annotation bitstream in ANNODEX(TM) format bitstreams, but also has some additional tags required for identifying and synchronising one or several time-continuous bitstreams that will be multiplexed together for the creation of one conherent ANNODEX(TM) format bitstream. The following picture illustrates the multiplexing activity:

-<------- | Multiplexing | v ---------------------------------------------------------------------- |stream|head|anchor_1| media packets |anchor_2| media packets ... ---------------------------------------------------------------------- ]]>

The file extension of CMML files is ".cmml". This document also applies for registration of the mime-type "text/cmml" for CMML files. The CMML is technically fully specified through its DTD as given in the Appendix. The semantic meaning of each of the tags, their content and their attributes is specified in the following sections. The Appendix also contains an example of a CMML (instance) document.

At the beginning of the CMML DTD, several parameter entities are defined that are used throughout the DTD as data types. This section gives a brief overview of them and refers to the relevant standards in which they are defined.

A "URI" is a character string that conforms to the specification of the Uniform Resource Identifier as defined in RFC 2396. The currently proposed temporal URI fragment identifier specification is supported, too. A URI generally points to a Web resource.

The "LanguageCode" defines a collection of constant strings that each identify a specific language as defined in RFC 1766. It is used to provide internationalisation support. To that end, the i18n entity draws together a language given by a "LanguageCode" with the directionality of that language in "dir" given either as ltr (left-to-right) or rtl (right-to-left).

There are three different time specifications in use in CMML: "Timestamp", "Playbacktime" and "UTCtime". A "Timestamp" is generally a name-value pair which defines a time point. The time point value is interpreted according to the time scheme given in the name. If the name is ommitted, it defaults to "npt=". The available time specifications stem from different sources: "npt" is "normal playback time" as used in the RTSP standard. "smpte" are several frame-based time labels as defined by the Society of Motion Pictures and Television Engineers. As fractional frames are meaningless for video and ambiguous for audio in the drop-frame situations, they are not used. The drop-frame algorithms for calculating the exact times can be found in the mentioned SMPTE standard. "utc" is the "universal time code" as specified in the ISO 8601 standard. Thus, the available time schemes are: "npt=" NPT time with a second or subsecond basis Specification as BNF: "smpte-24=" SMPTE time with a 24 fps basis "smpte-24-drop=" SMPTE time with a 24/1.001 fps basis "smpte-25=" SMPTE time with a 25 fps basis "smpte-30=" SMPTE time with a 30 fps basis "smpte-30-drop=" SMPTE time with a 30/1.001 fps basis "smpte-50=" SMPTE time with a 50 fps basis "smpte-60=" SMPTE time with a 60 fps basis "smpte-60-drop=" SMPTE time with a 60/1.001 fps basis Specification as BNF: "clock=" UTC time with a second or subsecond basis Specification as BNF: The "Playbacktime" entity is a data type that just specifies a SMPTE or a NPT time. It is therefore equal to the Timestamp entity without the UTC specification. The "UTCtime" entity is a data type that just specifies a UTC time without an identifier. UTC time is specified as in the Timestamp entity, but without the "clock=" identifier.

A CMML file is an XML instance document of the CMML DTD. An example is given in the Appendix. It starts with the usual xml directive and the DTD specification (see http://www.w3.org/TR/REC-xml#sec-prolog-dtd). This is an example preamble:

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After the preamble, the CMML tags follow. A CMML file has a "cmml" tag as the root element. It embraces all the other tags.

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The "cmml" tag encloses at most one "stream" element, exactly one "head" element, and as many "a" elements as the document author requires. An "a" element describes a fragment of the to be created ANNODEX(TM) bitstream. The ANNODEX(TM) bistream is created by multiplexing the bitstreams given in the "location" attributes of the "media" tags of the "stream" element together with the CMML annotations in a time-synchronous manner, as specified in the ANNODEX(TM) format. Attributes of the "cmml" element are the usual xml root tag attributes: an identifier "id" and a namespace "xmlns".

The "stream" element contains information about the input time-continuous bitstreams that are to be multiplexed together on authoring the ANNODEX(TM) format bitstreams.

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The "timebase" attribute contains a playback time in seconds associated with that first data packet. All other times in the CMML file MUST be calculated relative to this timebase. For example, a timebase of 300 seconds npt for a video file implies that the first frame is related to a play time of 300 seconds, and an anchor with a start time of 350 seconds is to be included 50 seconds into the ANNODEX(TM) bitstream. If no timebase is given, the timebase defaults to 0 npt. The timebase can be given as a SMPTE or NPT time, not as a utc time. The "utc" attribute associates a calendar date and a wall-clock time with the timebase. It therefore provides a mapping of the timebase to a real-world clock time and is given as a UTC time. If it is omitted, the start attribute in the media tag, and the start and end attributes in anchor tags MUST NOT be specified as UTC times. The content model of the "stream" tag then proposes an arbitrary number of input bitstreams. These are described one by one in the "media" element.

A "media" tag contains information on one of the input bitstreams for the multiplexing process. The relevant bitstream (fragment) is referenced through the "location" attribute. The location is a URI and may thus also contain a temporal URI fragment specification which narrows down the input file to that given subpart. That resource is multiplexed into the ANNODEX(TM) format bitstream starting at the time given in the "start" attribute and ending at the latest at the time given in the "end" attribute. The "start" and "end" attributes are interpreted relative to the timeline of the ANNODEX(TM) format bitstream.

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The "granulerate" attribute contains the base temporal resolution in Hz of the input bitstream refered in the "location" attribute. It depends on the encoding format of the input bitstream and typically contains the framerate for video (e.g. 25 frames/sec) and the samplerate for audio (e.g. 44100 samples/sec), but may contain any rational number given with an integer denominator larger than 1 sec (e.g. 25 frames on 2 seconds). Each bitstream has its own granulerate dependent on its specific encoding. This attribute is implied as it can be determined automatically during the multiplexing process when the headers of the encoded media bitstream contain this information. For bitstreams without header, such as uncompressed audio, the author of the CMML file can provide the granulerate to the multiplexer in this attribute. The "mimetype" attribute specifies the MIME type of the input bitstream refered in the "location" attribute. It is optional as the MIME type can often be derived easily from the file name or file header of the media source during multiplexing. The "location" attribute specifies a URI to the input bitstream. Commonly used URI schemes are "file" and "http". For specifying temporal subsets of the input bitstream, use the temporal URI fragment specification. The "start" attribute specifies a time in the output ANNODEX(TM) bitstream at which the media bitstream will be inserted. This time is specified with respect to the "timebase" attribute given in the "stream" element. The "end" attribute specifies a time in the output ANNODEX(TM) bitstream at which the media bitstream stop at the latest. This time is also specified with respect to the "timebase" attribute given in the "stream" element. This attribute is not required when the full bitstream is used.

The CMML "head" element contains annotation information on the complete ANNODEX(TM) bitstream, which the CMML file is used to create. It therefore contains header-type information such as a title for the bitstream, and meta information describing the bitstream. The "head" element is declared as the following:

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The "head" tag must contain a "title" tag. It may contain one "base" tag before or after the "title" tag and any number of "meta" tags at any position. The "%i18n;" attribute specifies the base language of the "head" tag's attribute values. The "defltlang" and "defltdir" attributes specify the default language (language and directionality) of the anchor tags. The value of the "profile" attribute is a space-separated list of base URIs specifying locations of "meta" tag schemes. These schemes may be used in the "meta" elements of the "head" or the "a" tags.

The "title" tag gives a descriptive title for the ANNODEX(TM) bitstream. The "title" element is declared as the following:

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The "%i18n;" attribute specifies the base language of the "title" text.

The "base" element defines the base URI of the ANNODEX(TM) bitstream. All relative URIs of the bitstream get interpreted relative to this base. The "base" element is empty, but its attributes contain the base URI. It is declared as follows:

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The "href" attribute contains the base URI.

The "meta" element defines structured annotations for the complete ANNODEX(TM) bitstream. A "meta" element is empty, but its attributes contain the name-value pairs of a structured annotation. The "meta" element is declared as follows:

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The "%i18n;" attribute specifies the default language of the meta attribute and content texts. The "name" attribute identifies a property name. It does not list legal values for this attribute. The "content" attribute specifies a property's value. It does not list legal values for this attribute. The "scheme" attribute names a scheme to be used to interprete the property's value. The scheme can be located via the "profile" attribute in the "head" element.

A CMML file typically contains a number of anchors given in "a" tags. The CMML "a" tag contains information about a fragment of the ANNODEX(TM) bitstream. This is expressed in a number of elements and attributes annotating, indexing, and hyperlinking the fragment. The "start" and "end" attributes are used to give the insertion time for the anchor into the ANNODEX(TM) bitstream.

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Any number of "meta" and "desc" elements may appear in an anchor page, but the "meta" elements must all appear first and en bloc, while the "desc" elements must all appear last and also en bloc. An "a" element defines a name for the fragment in the "id" attribute. This name can be used in URIs that point either to the CMML file or the ANNODEX(TM) bitstream created from it. It will be used as a fragment identifier and point straight to the fragment defined by the "a" tag. The "%i18n;" attribute specifies the default language used by all the "desc" elements of the "a" tag. The "track" attribute specifies the track that this anchor belongs to. An annotation track is a set of "a" pages that belong together from a semantic point of view. Anchors in the same track must not overlap temporally. A default track must be available always. This track is the one a client (such as a Web browser plugin) will display by default. Other annotation tracks may be created by the document author to describe a more specific content. An example use are different annotation tracks for each speaker in an audio recording of a meeting. The "href" attribute specifies the location of a Web resource given by a URI. It thus defines a link between the current fragment and a resource which the author believes to be connected closely to this fragment's content. This might be a html page or another ANNODEX(TM) bitstream fragment or an image etc. The "hrefdesc" attribute gives a short textual description of the link specified through the "href" attribute. It explains why the connection between the current fragment and the destination URI is made. It may e.g. encourage the viewer to follow the link to "Get more information on blah". This attribute value can be specified only if the "href" attribute has been specified. The "image" attribute specifies the location of an image on the Web given by a URI. This image should be quite small as it is the representative image (known as "keyframe") for the current fragment. This image may be used to visually summarise the content of the fragment when a link to it is displayed, e.g. by a search engine or in a table of contents. The "start" and "end" attributes specify the time range during which the anchor element is defined. This time range is specified with respect to the "timebase" and "utc" attributes given in the "stream" tag. If the "stream" tag does not contain a "utc" specification, "start" and "end" times are not allowed to be given in UTC time. "start" is a required attribute because an achor without a start time is useless. "end" is optional and only required where anchors cannot continue on to the following anchor.

The "meta" element is specified above in the "head" section. While a "meta" element in the "head" tag provides meta information for the complete ANNODEX(TM) bitstream, the "meta" elements in an "a" tag only provide meta information for the anchor.

The "desc" tag contains a human readable, textual description (or annotation) of the content of the fragment. The "desc" element is declared as the following:

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For extracting a short text from the "desc" element as needs to be displayed in a table of contents or as caption, the first few characters of the description will be taken. It therefore is recommended to place a short meaningful summary sentence at the beginning of the description when authoring annotations. The "%i18n;" attribute specifies the actual language of the text in the description. So, if it is required to give a mixed language description, the default language will be given in the "%i18n;" attribute of the "a" tag and the actually used language in a specific "desc" tag is given there.

As CMML is an authoring format for ANNODEX(TM) format bitstreams, there is a simple way to map the annotations and meta information contained in a CMML instance document to the annotation bitstreams and header fields of an ANNODEX(TM) format bitstream. There is a direct mapping between a CMML "head" element and an ANNODEX(TM) "head" page as they both contain the same elements and the same attributes. The additional namespace attribute "xmlns" in the "head" page of an ANNODEX(TM) format bitstream will be filled from the "xmlns" attribute of the "cmml" tag of the CMML file and defaults to the same namespace default. There is also a direct mapping between a CMML "a" element and an ANNODEX(TM) "a" page as they also both contain the same elements and the same attributes, except for the "start" and "end" attributes. The "start" attribute tells the multiplexer that creates the ANNODEX(TM) format bitstream at what time to insert the "a" page into the bitstream. The "end" attribute (if present) leads to the creation of an "empty" "a" page on the same track at the given time in the ANNODEX(TM) format bitstream unless another "a" page apears on the same track beforehand. The "empty" "a" page contains no attribute values for any of the implied attributes and no "meta" or "desc" elements, but has a copy of the "track" attribute. Again, the "xmlns" attribute is filled from the "xmlns" attribute of the "cmml" tag of the CMML file and defaults to the same namespace default. The information contained in a CMML "stream" element is partly relevant to authoring only and partly required in different binary header fields of an ANNODEX(TM) format bitstream. The "stream" attributes "timebase" and "utc" are stored in the bos page of the ANNODEX(TM) media mapping bitstream. Each of the encapsulated media bitstreams is described by one of the "media" tags in the CMML. Their "id", "granulerate" and "mimetype" attributes are stored in the bos page of the respective bitstreams. The other attributes of the "media" tag are used for authoring only and therefore not mapped to a field in the ANNODEX(TM) format bitstream.

This section contains the registration information for the 'text/cmml' media type. While this media type is not approved by the IANA, 'text/x-cmml' may be used to identify CMML instance documents. To: ietf-types@iana.org Subject: Registration of MIME media type 'text/cmml' MIME media type name: text MIME subtype name: cmml Required parameters: none Optional parameters: charset (as in the text/xml media type). Encoding Considerations: as appropriate for the charset and the transport mechanism (see text/xml media type). Security considerations: see next section. Interoperability considerations: CMML is a free specification that is independent of any media encoding format. It is designed to provide interoperability with existing XML tools and systems. Its specification is not patented and can be implemented by third parties without patent considerations. Additional information: Magic numbers: none. However, CMML files start with the XML preamble as any XML document) and will also have the string near the beginning of the file. File extension: .cmml Macintosh File Type Code: "TEXT" Intended usage: COMMON Fragment identifiers: Any named element, i.e. element that contains an "id" attribute, may be referenced through a fragment identifier of a URI. However, the values of the id attribute of the anchor tags are the most important ones used for addressing media fragments. Also, the generic temporal addressing scheme proposed for standardisation can be used as a fragment address and then relates to the last anchor whose start time is just before the given temporal offset.

As CMML is a markup language created by using XML, the same security considerations that apply to XML, apply to CMML. As the CMML is an authoring language for ANNODEX(TM) format bitstreams, there is no executable code attached to this language. The implementation of a multiplexer to actually create an ANNODEX(TM) bitstream must be careful when handling input bitstreams, which are binary data.

World Wide Web Consortium

MIT Laboratory for Computer Science 545 Technology Square Cambridge MA 02139 US + 1 617 253 2613 + 1 617 258 5999 timbl@w3.org http://www.w3c.org

World Wide Web Consortium

MIT Laboratory for Computer Science 545 Technology Square Cambridge MA 02139 US + 1 617 253 2613 + 1 617 258 5999 timbl@w3.org http://www.w3c.org

World Wide Web Consortium

MIT Laboratory for Computer Science 545 Technology Square Cambridge MA 02139 US + 1 617 253 2613 + 1 617 258 5999 timbl@w3.org http://www.w3c.org

World Wide Web Consortium

MIT Laboratory for Computer Science 545 Technology Square Cambridge MA 02139 US +1 617 253 5702 +1 617 258 8682 timbl@w3.org

University of California, Irvine

Department of Information and Computer Science University of California, Irvine Irvine CA 92697-3425 US +1 949 824 7403 +1 949 824 1715 fielding@ics.uci.edu

Xerox PARC

3333 Coyote Hill Road Palo Alto CA 94304 US +1 650 812 4365 +1 650 812 4333 masinter@parc.xerox.com

Columbia University

Dept. of Computer Science 1214 Amsterdam Avenue New York NY 10027 US schulzrinne@cs.columbia.edu

Netscape Communications Corp.

501 E. Middlefield Road Mountain View CA 94043 US anup@netscape.com

RealNetworks

1111 Third Avenue Suite 2900 Seattle WA 98101 US robla@real.com

UNINETT

Pb. 6883 Elgeseter Trondheim 7002 Norway Harald.T.Alvestrand@uninett.no

Innosoft Internationl, Inc.

1050 East Garvey Avenue South West Covina CA 91790 USA ned@innosoft.com

First Virtual Holdings

25 Washington Avenue Morristown NJ 07960 USA nsb@nsb.fv.com

University of California, Irvine

Department of Information and Computer Science Irvine CA 92697-3425 USA ejw@ics.uci.edu

Fuji Xerox Information Systems

KSP 9A7, 2-1, Sakado 3-chome, Takatsu-ku Kawasaki-shi Kanagawa-ken 213 Japan murata@fxis.fujixerox.co.jp

The Society of Motion Picture and Television Engineers

595 W. Hartsdale Ave. White Plains NY 10607 USA smpte@smpte.org

International Organization for Standardization

1 rue de Varembre Case Postale 56 Geneva 20 1211 CH central@iso.org

Commonwealth Scientific and Industrial Research Organisation

Locked Bag 17 North Ryde NSW 2113 Australia + 61 2 9325 3100 + 61 2 9325 3200 Silvia.Pfeiffer@csiro.au http://www.annodex.net

Commonwealth Scientific and Industrial Research Organisation

Locked Bag 17 North Ryde NSW 2113 Australia + 61 2 9325 3100 + 61 2 9325 3200 Conrad.Parker@csiro.au http://www.annodex.net

Commonwealth Scientific and Industrial Research Organisation

Locked Bag 17 North Ryde NSW 2113 Australia + 61 2 9325 3100 + 61 2 9325 3200 Silvia.Pfeiffer@csiro.au http://www.annodex.net

Commonwealth Scientific and Industrial Research Organisation

Locked Bag 17 North Ryde NSW 2113 Australia + 61 2 9325 3100 + 61 2 9325 3200 Conrad.Parker@csiro.au http://www.annodex.net

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There is no spoon: Neo is waiting to see the Oracle in a room full of children doing seemingly impossible things. One is making spoons bend through telekenesis. Neo tries to do it himself, but fails. Spoon boy: "Do not try and bend the spoon that's impossible, instead only try to realize the truth." Neo: "What truth?" Spoon boy: "There is no spoon." Neo: "There is no spoon?" Spoon boy: "Then you'll see that it is not the spoon that bends, it is only yourself." Neo tries again... Den Löffel gibt es nicht: Neo entdeckt beim Besuch des Orakels wie unwirklich seine Welt ist. Beim Versuch, einen Löffel durch Telekinese zu verbiegen, bekommt er von dem Kind den Rat: "Den Löffel gibt es nicht." ]]>

A subpart of a resource covering some temporal interval. XML tags and their content used to describe a media document. the task of giving textual descriptions to fragments of media documents. the task of identifying index points for media documents or fragments thereof. the task of linking from one Web resource to another. If a link has a fragment offset into the resource, this is sometimes called deep hyperlinking. a set of Anchor pages representing semantically correlated annotations of a time-continuous resource. A specific file format for storing annotation, hyperlinking, and indexing information multiplexed together with the time-continuous data bitstreams they describe. a sequence of data containing samples of time-continous data.

Annotated and indexed bitstream format. Continuous Media Markup Language. Document Type Declaration. eXtensible Markup Language. World Wide Web. Unified Resource Identifier.

The authors greatly acknowledge the contributions of Andre Pang, Andrew Nesbit, and Simon Lai in developing this standard.