TOC 
Network Working GroupS. Pfeiffer
Internet-DraftC. Parker
Expires: December 7, 2003CSIRO
 June 8, 2003

Specification of the Continuous Media Markup Language (CMML), Version 1.0
draft-pfeiffer-cmml-00

Status of this Memo

This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026 except that the right to produce derivative works is not granted.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt.

The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html.

This Internet-Draft will expire on December 7, 2003.

Copyright Notice

Copyright (C) The Internet Society (2003). All Rights Reserved.

Abstract

This specification defines the Continuous Media Markup Language (CMML), version 1.0, an XML-based[1] markup language for time-continuous data. It is a sister document to the specification of the ANNODEX(TM)[12] 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)[12] 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[3].

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.



 TOC 

Table of Contents




 TOC 

1. Introduction

Please note that this document assumes that the reader has a fluent working knowledge of XML[1], HTML[2], XHTML[3] and the World Wide Web. Knowledge about the ANNODEX(TM)[12] 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:

   ----------
   |stream  | CMML
   ---------- instance
   | head   | document
   ----------
   |anchor_1|     ----------------------------------------------------
   ----------     | media bitstream in packets                       |
   | ...    |     ----------------------------------------------------
   ----------          |
   |anchor_n|          |
   ----------          |
       |               |
       ------->-<-------
               |
          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.



 TOC 

2. The CMML data types

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.

2.1 URIs

A "URI" is a character string that conforms to the specification of the Uniform Resource Identifier as defined in RFC 2396[4]. The currently proposed temporal URI fragment identifier specification[11] is supported, too. A URI generally points to a Web resource.

2.2 Internationalisation support

The "LanguageCode" defines a collection of constant strings that each identify a specific language as defined in RFC 1766[6]. 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).

2.3 Time specifications

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:

Thus, the available time schemes are:

"npt=" NPT time with a second or subsecond basis

Specification as BNF:

npt-spec    =  "npt=" npt-time
npt-time    =  npt-sec | npt-hhmmss
npt-sec     =   1*DIGIT [ "." *DIGIT ]
npt-hhmmss  =   npt-hh ":" npt-mm ":" npt-ss [ "." *DIGIT ]
npt-hh      =   1*DIGIT
npt-mm      =   1*2DIGIT
npt-ss      =   1*2DIGIT
        

"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:

smpte-spec  = smpte-type "=" smpte-time
smpte-type  = "smpte-24" | "smpte-24-drop" | "smpte-25" |
              "smpte-30" | "smpte-30-drop" | "smpte-50" |
              "smpte-60" | "smpte-60-drop"
smpte-time  =  1*2DIGIT ":" 1*2DIGIT ":" 1*2DIGIT [ ":" 1*2DIGIT ]
        

"clock=" UTC time with a second or subsecond basis

Specification as BNF:

utc-spec    = "clock=" utc-time
utc-time    =   utc-date "T" utc-hhmmss "Z"
utc-date    =   8DIGIT
utc-hhmmss  =   6DIGIT [ "." *DIGIT ]
        

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.



 TOC 

3. The preamble and the 'cmml' root element

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:

<?xml version="1.0"encoding="UTF-8"?>
<!DOCTYPE cmml SYSTEM "cmml.dtd">
	    

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

<!ELEMENT cmml (stream?, head, a*)>
<!ATTLIST cmml
  id          ID             #IMPLIED
  xmlns       %URI;          #FIXED 'http://www.annodex.net/cmml'
  >
	    

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[12].

Attributes of the "cmml" element are the usual xml root tag attributes: an identifier "id" and a namespace "xmlns".



 TOC 

4. The cmml 'stream' tag

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

<!ELEMENT stream (media*)>
<!ATTLIST stream
  id          ID             #IMPLIED
  timebase    %Playbacktime; "npt=0"
  utc         %UTCtime;      #IMPLIED
  >
	    

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.

4.1 The 'media' tag

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.

<!ELEMENT media EMPTY>
<!ATTLIST media 
  id          ID             #IMPLIED
  granulerate CDATA          #IMPLIED
  mimetype    CDATA          #IMPLIED
  location    %URI;          #REQUIRED
  start       %Timestamp;    "npt=0"
  end         %Timestamp;    #IMPLIED
>
	    

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[7] 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[11] 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.



 TOC 

5. The cmml 'head' element

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:

<!ELEMENT head (meta*,
                ((title, meta*, (base, meta*)?) |
                 (base, meta*, (title, meta*)?)))>
<!ATTLIST head
  id          ID             #IMPLIED
  %i18n;
  defltlang   %LanguageCode; #IMPLIED
  defltdir    (ltr|rtl)      #IMPLIED
  profile     %URI;          #IMPLIED
  >
	    

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.

5.1 The 'title' element

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

<!ELEMENT title (#PCDATA)>
<!ATTLIST title
  id          ID       #IMPLIED
  %i18n;
>
	    

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

5.2 The 'base' element

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:

<!ELEMENT base EMPTY>
<!ATTLIST base
  id      ID       #IMPLIED
  href    %URI;    #REQUIRED
>
	    

The "href" attribute contains the base URI.

5.3 The 'meta' element

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:

<!ELEMENT meta EMPTY>
<!ATTLIST meta
  id       ID       #IMPLIED
  %i18n;
  name     NMTOKEN  #IMPLIED
  content  CDATA    #REQUIRED
  scheme   CDATA    #IMPLIED
>
	    

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.



 TOC 

6. The cmml 'a' tag

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.

<!ELEMENT a (meta*, desc*)>
<!ATTLIST a
  id          ID             #IMPLIED
  %i18n;
  track       CDATA          "default"
  href        %URI;          #IMPLIED
  hrefdesc    CDATA          #IMPLIED
  image       %URI;          #IMPLIED
  start       %Timestamp;    #REQUIRED
  end         %Timestamp;    #IMPLIED
>
	    

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.

6.1 The 'meta' element

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.

6.2 The 'desc' element

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:

<!ELEMENT desc  (#PCDATA)>
<!ATTLIST desc
  id          ID       #IMPLIED
  %i18n;
>
	    

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.



 TOC 

7. The mapping of CMML to ANNODEX(TM) format bitstreams

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.



 TOC 

8. MIME media type registration for 'text/cmml'

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[8]).

Encoding Considerations: as appropriate for the charset and the transport mechanism (see text/xml media type[8]).

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[8]) and will also have the string '<cmml' 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[11] can be used as a fragment address and then relates to the last anchor whose start time is just before the given temporal offset.



     TOC 

    9. Security considerations

    As CMML is a markup language created by using XML, the same security considerations that apply to XML[8], 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.



     TOC 

    References

    [1] World Wide Web Consortium, "Extensible Markup Language (XML) 1.0", W3C XML, October 2000.
    [2] World Wide Web Consortium, "HTML 4.01 Specification", W3C HTML, December 1999.
    [3] World Wide Web Consortium, "XHTML(TM) 1.0 The Extensible Hyper Text Markup Language", W3C XHTML, January 2000.
    [4] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998.
    [5] Schulzrinne, H., Rao, A. and R. Lanphier, "Real Time Streaming Protocol (RTSP)", RFC 2326, April 1998.
    [6] Alvestrand, H., "Tags for the Identification of Languages", RFC 1766, March 1995.
    [7] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types", RFC 2046, November 1996.
    [8] Whitehead, E. and M. Murata, "XML Media Types", RFC 2376, July 1998.
    [9] The Society of Motion Picture and Television Engineers, "SMPTE STANDARD for Television, Audio and Film - Time and Control Code", ANSI 12M-1999, September 1999.
    [10] ISO, TC154., "Data elements and interchange formats -- Information interchange -- Representation of dates and times", ISO 8601, 2000.
    [11] Pfeiffer, S. and C. Parker, "Syntax of temporal URI fragment specifications (work in progress)", I-D draft-pfeiffer-temporal-fragments-00.txt, Feburary 2003.
    [12] Pfeiffer, S. and C. Parker, "Specification of the ANNODEX(TM) annotation and indexing format for time-continuous data files, Version 1.0 (work in progress)", I-D draft-pfeiffer-annodex-00.txt, June 2003.


     TOC 

    Authors' Addresses

      Silvia Pfeiffer
      Commonwealth Scientific and Industrial Research Organisation CSIRO, Australia
      Locked Bag 17
      North Ryde, NSW 2113
      Australia
    Phone:  +61 2 9325 3141
    EMail:  Silvia.Pfeiffer@csiro.au
    URI:  http://www.cmis.csiro.au/Silvia.Pfeiffer/
      
      Conrad D. Parker
      Commonwealth Scientific and Industrial Research Organisation CSIRO, Australia
      Locked Bag 17
      North Ryde, NSW 2113
      Australia
    Phone:  +61 2 9325 3133
    EMail:  Conrad.Parker@csiro.au
    URI:  http://www.cmis.csiro.au/Conrad.Parker/


     TOC 

    Appendix A. CMML DTD

    <?xml version="1.0" encoding="UTF-8" ?>
    
    <!--
    
       Continuous Media Markup Language CMML version 1.0 DTD
       Authoring language for ANNODEX(TM) media.
    
       Namespace = http://www.annodex.net/cmml
    
       Copyright (c) 2001 
       Commonwealth Scientific and Industrial Research Organisation
       (CSIRO), Australia.
       All Rights Reserved. 
    
       This DTD module is identified by the PUBLIC and SYSTEM identifiers:
    
       PUBLIC "-//CSIRO//DTD CMML 1.0//EN"
       SYSTEM "http://www.annodex.net/DTD/cmml_1_0.dtd"
    
       $Revision: 1.0 $
       $Date: 2003/06/01 24:00:00 $
    -->
    
    <!-- **************************** -->
    <!-- Definition of Imported Names -->
    <!-- **************************** -->
    
    <!-- a Uniform Resource Identifier, see [RFC2396] -->
    <!ENTITY % URI "CDATA">
    
    <!-- a language code, as per [RFC1766] -->
    <!ENTITY % LanguageCode "NMTOKEN">
    
    <!-- internationalization attributes
      xml:lang    language code (as per XML 1.0 spec)
      dir          direction for weak/neutral text
    -->
    <!ENTITY % i18n
     "lang    %LanguageCode; #IMPLIED
      dir         (ltr|rtl)      #IMPLIED"
      >
    
    <!-- timestamps similar to [RFC2326] 
     "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
     "npt=" npt-time
     "clock=" utc-time
    
     Playbacktime is specified as a smpte-time 
     or npt-time only.
    
     UTCtime is specified as in [RFC2326], but
     without the "clock" identifier
    -->
    <!ENTITY % Timestamp    "CDATA">
    <!ENTITY % Playbacktime "CDATA">
    <!ENTITY % UTCtime      "CDATA">
    
    
    <!-- **************************** -->
    <!-- Document Structure           -->
    <!-- **************************** -->
    
    <!-- ROOT ELEMENT: -->
    <!-- cmml tag containing sequence of head and a tags -->
    <!-- =============================================== -->
    <!-- xmlns   = namespace of the cmml tags -->
    <!-- (language of this is covered by the default language 
          given in the head element) -->
    <!ELEMENT cmml (stream?, head, a*)>
    <!ATTLIST cmml
      id          ID             #IMPLIED
      xmlns       %URI;          #FIXED 'http://www.annodex.net/cmml'
      >
    
    
    <!-- **************************** -->
    <!-- Definition of stream element -->
    <!-- **************************** -->
    
    <!-- STREAM tag providing timing information for the ANNODEX file -->
    <!-- (will be stored in the binary headers of the ANX bitstreams) -->
    <!-- ============================================================ -->
    <!-- timebase   = base time associated with the first frame of the media 
                      document from which subsequent time references (such as 
                      in anchor tags) will be taken relative to -->
    <!-- utc        = a mapping of the first frame to clock time; 
                      specifications of utc time offsets into the document as
                      in a URI will be taken relative to this -->
    <!ELEMENT stream (media*)>
    <!ATTLIST stream
      id          ID             #IMPLIED
      timebase    %Playbacktime; "npt=0"
      utc         %UTCtime;      #IMPLIED
      >
    
    <!-- MEDIA tag giving descriptions on a media bitstream (empty content) -->
    <!-- ================================================================== -->
    <!-- granulerate = the base temporal resolution of the bitstream (.e.g.
                       its framerate for video or samplerate for audio) -->
    <!-- mimetype    = encoding format of the media document (a MIME type) -->
    <!-- location    = URI to the media document -->
    <!-- start       = the start time of the media bitstream specified
                       in location  -->
    <!ELEMENT media EMPTY>
    <!ATTLIST media 
      id          ID             #IMPLIED
      granulerate CDATA          #IMPLIED
      mimetype    CDATA          #IMPLIED
      location    %URI;          #REQUIRED
      start       %Timestamp;    "npt=0"
      end         %Timestamp;    #IMPLIED
      >
    
    
    <!-- **************************** -->
    <!-- Definition of document head  -->
    <!-- **************************** -->
    
    <!-- head tag containing description of a specific media document -->
    <!-- ============================================================ -->
    <!-- profile = space-separated list of URIs to locate meta tag schemes -->
    <!-- i18n    = the base language of the head's attribute values and text 
                   content -->
    <!-- defltlang & defltdir  = the default language for the whole document -->
    <!ELEMENT head (meta*,
                    ((title, meta*, (base, meta*)?) |
    		 (base, meta*, (title, meta*)?)))>
    <!ATTLIST head
      id          ID             #IMPLIED
      %i18n;
      defltlang   %LanguageCode; #IMPLIED
      defltdir    (ltr|rtl)      #IMPLIED
      profile     %URI;          #IMPLIED
      >
    
    <!-- TITLE tag giving descriptive title of the media document  -->
    <!-- ========================================================= -->
    <!-- i18n  = the base language of the title -->
    <!ELEMENT title (#PCDATA)>
    <!ATTLIST title 
      id          ID             #IMPLIED
      %i18n;
      >
    
    <!-- BASE URI of the document (empty content) --> 
    <!-- ======================================== -->
    <!-- href = URI associated with the document; all relative URI references
                get interpreted relative to this base -->
    <!ELEMENT base EMPTY>
    <!ATTLIST base
      id          ID             #IMPLIED
      href        %URI;          #REQUIRED
      >
    
    <!-- META description tags of the document (empty content) -->
    <!-- ===================================================== -->
    <!-- i18n    = the default language for the meta attribute and content text -->
    <!-- name    = identifies a property name; does not list legal values for this 
                   attribute --> 
    <!-- content = specifies a property's value; does not list legal values for 
                   this attribute -->
    <!-- scheme  = names a scheme to be used to interpret the property's value 
                   (see the profiles tag in the head element for locating these) -->
    <!ELEMENT meta EMPTY>
    <!ATTLIST meta
      id          ID             #IMPLIED
      %i18n;
      name        NMTOKEN        #IMPLIED
      content     CDATA          #REQUIRED
      scheme      CDATA          #IMPLIED
      >
    
    
    <!-- **************************** -->
    <!-- Definition of anchor tags    -->
    <!-- **************************** -->
    
    <!-- A tag containing information for a specific fragment -->
    <!-- ==================================================== -->
    <!-- i18n     = default language for all the desc tags in the anchor -->
    <!-- track    = defines different sets of anchor tags; anchor tags of same 
                    type cannot overlap temporally-->
    <!-- href     = specifies the location of a Web resource, thus defining a 
                    link between the current element (the source anchor) and the 
                    destination anchor given by this attribute -->
    <!-- hrefdesc = textual description of the link between the current element 
                    (the source anchor) and the destination anchor given by the 
                    href attribute -->
    <!-- image    = link to an image that is representative for this fragment -->
    <!-- start    = specifies the start time of the fragment; specified in 
                    time relative to the timebase of the header 
                    [NOT INCLUDED IN ANNODEXED DOCUMENT] -->
    <!-- end      = specifies the end time of the fragment; specified in 
                    time relative to the timebase of the header 
                    [NOT INCLUDED IN ANNODEXED DOCUMENT] -->
    <!ELEMENT a (meta*, desc*)>
    <!ATTLIST a
      id          ID             #IMPLIED
      %i18n;
      track       CDATA          "default"
      href        %URI;          #IMPLIED
      hrefdesc    CDATA          #IMPLIED
      image       %URI;          #IMPLIED
      start       %Timestamp;    #REQUIRED
      end         %Timestamp;    #IMPLIED
      >
    
    <!-- DESC human-readable, textual description of the anchor (annotation) -->
    <!-- =================================================================== -->
    <!-- i18n = language of the data in the description, as per [RFC1766] -->
    <!ELEMENT desc (#PCDATA)>
    <!ATTLIST desc
      id          ID             #IMPLIED
      %i18n;
      >
    	  


     TOC 

    Appendix B. An example CMML document

    <?xml version="1.0" encoding="UTF-8"?> 
    <!DOCTYPE cmml SYSTEM "cmml_1_0.dtd">
    <cmml>
    <stream timebase="npt=0" utc="19911222T210000.00Z"/>
      <media location="matrix.mpg" mimetype = "video/mpeg" 
             granulerate="25/1" start="npt=0"/>
    </stream>
    <head lang="en" defltlang="de">
      <title lang="en">The Matrix</title>
      <base href="http://www.foo.bar/"/>
      <meta name="Movie"     content="The Matrix"/>
      <meta name="Producer"  content="Joel Silver"/>
      <meta name="Director"  content="Larry Wachowski"/>
      <meta name="Director"  content="Andy Wachowski"/>
      <meta name="Writer"    content="The Wachowski Brothers"/>
    </head>
    <a id="no_spoon" 
       lang="en"
       href="http://www.blah.au/spoons.anx#@bent"
       hrefdesc="More images of the bent spoon"
       image="no_spoon.jpg"
       start="npt=46:5.9"
       end="npt=51:3.4">
      <meta name="Actor"       content="Keanu Reeves"/>
      <meta name="Actor"       content="Rowan Witt"/>
      <meta name="Cast.Reeves" content="Thomas A. Anderson/Neo"/>
      <meta name="Cast.Witt"   content="Spoon boy"/>
      <meta name="Scene"       content="Oracle"/>
      <desc>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...
      </desc>
      <desc lang="de">Den L&ouml;ffel gibt es nicht: Neo entdeckt beim Besuch
      des Orakels wie unwirklich seine Welt ist. Beim Versuch, einen
      L&ouml;ffel durch Telekinese zu verbiegen, bekommt er von dem Kind den
      Rat: "Den L&ouml;ffel gibt es nicht."
      </desc>
    </a>
    </cmml>
    	    


     TOC 

    Appendix C. Definitions of terms and abbreviations

    Anchor:
    A subpart of a resource covering some temporal interval.
    Mark-up:
    XML tags and their content used to describe a media document.
    Annotating:
    the task of giving textual descriptions to fragments of media documents.
    Indexing:
    the task of identifying index points for media documents or fragments thereof.
    Hyperlinking:
    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.
    Track:
    a set of Anchor pages representing semantically correlated annotations of a time-continuous resource.
    ANNODEX(TM) bitstream:
    A specific file format for storing annotation, hyperlinking, and indexing information multiplexed together with the time-continuous data bitstreams they describe.
    Bitstream:
    a sequence of data containing samples of time-continous data.



     TOC 

    Appendix D. Glossary of acronyms

    ANNODEX(TM):
    Annotated and indexed bitstream format.
    CMML:
    Continuous Media Markup Language.
    DTD:
    Document Type Declaration.
    XML:
    eXtensible Markup Language.
    Web:
    World Wide Web.
    URI:
    Unified Resource Identifier.



     TOC 

    Appendix E. Acknowledgements

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



     TOC 

    Intellectual Property Statement

    Full Copyright Statement

    Acknowledgement