Trace: • descriptor
Table of Contents

The <descriptor> Element

Definition and Usage

The <descriptor> element defines the initial values for properties of <media> elements. These initial values are defined in attributes of the element, or in child <descriptorParam> elements.

Syntax

Element Attributes Content Parent
<descriptor> id, player, explicitDur, region, freeze, moveLeft, moveRight, moveUp, moveDown, focusIndex, focusBorderColor, focusBorderWidth, focusBorderTransparency, focusSrc, focusSelSrc, selBorderColor, transIn, transOut (<descriptorParam>)* <descriptorBase>

Attributes

Name Value Description
id It may receive any string value that begins with a letter or an underscore and that only contains letters, digits, “.”, and “_”. The id attribute uniquely identifies the element within a document.
player String. If not specified, the player is determined by the object type, defined by the type attribute of the <media> element, or is inferred by the file extension used in the src attribute of the <media> element. Identifies the presentation tool to be used.
explicitDur

The delay attribute is be specified according with one of the following syntax:

  1. “Hours:Minutes:Seconds.Fraction”, where “Hours” is an integer in the [0,23] interval, “Minutes” is an integer in the [0,59] interval, “Seconds” is an integer in the 0,59 interval, and “Fraction” is a positive integer,
  2. Seconds“s”, where “Seconds” is a positive real number.

For continuous media, the default value shall be set to the natural duration, otherwise it must be set to nil.

 Gives the duration of an object.
region IDREF. The region attribute identifies a <region> element used to initialize the left, right, top, bottom, height, width, and zIndex properties of the <media> element that refers to the <descriptor> element.
freeze

“true” or “false”.

The default value is “false”.

 The freeze attribute defines what will happen with an object at the end of its presentation, if the end content is frozen (“true”) or not (“false”).
moveLeft Positive integer. The moveLeft attribute specifies a value equal to the focusIndex value associated to an element to which the focus should be applied when the “left-arrow” key is pressed.
moveRight Positive integer. The moveRight attribute specifies a value equal to the focusIndex value associated to an element to which the focus should be applied when the “right-arrow” key is pressed.
moveUp Positive integer. The moveUp attribute specifies a value equal to the focusIndex value associated to an element to which the focus should be applied when the “up-arrow” key is pressed.
moveDown Positive integer. The moveDown attribute specifies a value equal to the focusIndex value associated to an element to which the focus should be applied when the “down-arrow” key is pressed.
focusIndex Positive integer The focusIndex attribute specifies an index for the <media> element to which the focus may be applied. When the corresponding property is not defined, the object is considered as if no focus could be set.
focusBorderColor

“white”, “black”, “silver”, “gray”, “red”, “maroon”, “fuchsia”, “purple”, “lime”, “green”, “yellow”, “olive”, “blue”, “navy”, “aqua”, or “teal”.

The default value is given by the “default.focusBorderColor” property of the settings object.

 Defines the color to decorate the screen region where the object on focus is being presented, before it is selected.
focusBorderWidth

Integer.

The default value is defined by the “default.focusBorderWidth” property of the settings object.

 Width, in pixels, applied to the border of an element in focus.
focusBorderTransparency

A real number in the [0,1] interval, or a real number in the [0,100] interval ending with the character “%” (e.g. “30%”).

The default value is defined by the “default.focusTransparency” property of the settings object.

 Transparency applied to the border of an element in focus, with 1 or 100% meaning full transparency and 0 or 0% meaning no transparency.
focusSrc

The following are valid values:

  • “file:///file_path/#fragment_identifier” – for local files,
  • “http://server_identifier/file_path/#fragment_identifier” – for remote files downloaded using the HTTP protocol,
  • “https://server_identifier/file_path/#fragment_identifier” – for remote files downloaded using the HTTPS protocol,
  • “rtsp://server_identifier/file_path/#fragment_identifier” – for streams downloaded using the RTSP protocol,
  • “rtp://server_identifier/file_path/#fragment_identifier” – for streams downloaded using the RTP protocol,
  • “ncl-mirror://media_element_identifier” – for a content flow identical to the one in presentation by another <media> element,
  • “sbtvd-ts:” or “isdb-ts:” or “ts://program_number.component_tag” – for elementary streams received from the transport stream.

For src attribute whose value identifies the “sbtvd-ts”, “isdb-ts”, or “ts” scheme, the “program_number.component_tag”, can be substituted by the following reserved words:

  • “video” – corresponding to the primary video ES being presented on the video plan,
  • “audio” – corresponding to the primary audio ES,
  • “text” – corresponding to the primary text ES,
  • “video(i)” – corresponding to the i-th smaller video ES “component_tag” listed in the PMT of the tuned services,
  • “audio(i)” – corresponding to the i-th smaller audio ES “component_tag” listed in the PMT of the tuned services, or
  • “text(i)” – corresponding to the i-th smaller text ES “component_tag” listed in the PMT of the tuned services.
 The focusSrc attribute can specify an alternative media source to be presented, instead of the current presentation, if an element receives the focus. This attribute follows the same rules of the src attribute of the <media> element.
focusSelSrc Same as for focusSrc. When an element on focus is selected, by pressing the activation (“SELECT” or “ENTER”) key, the focusSelSrc property can specify an alternative media source to be presented, instead of the current presentation. This attribute follows the same rules of the src attribute of the <media> element.
selBorderColor

“white”, “black”, “silver”, “gray”, “red”, “maroon”, “fuchsia”, “purple”, “lime”, “green”, “yellow”, “olive”, “blue”, “navy”, “aqua”, or “teal”.

The default value is given by the “default.selBorderColor” property of the settings object.

 Defines the color to decorate the screen region where the object on focus is being presented, after it is selected.
transIn Semicolon-separated list of IDREFs. The transIn attribute is a semicolon-separated list of <transition> element identifiers.
transOut Semicolon-separated list of IDREFs. The transOut attribute is a semicolon-separated list of <transition> element identifiers.
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