School of Computer Science & Information Technology G6DPMM - Lecture 18 Synchronized Multimedia Integration Language (SMIL)

SMIL Synchronized Multimedia Integration Language Synchronized Multimedia Integration Language XML application for multimedia XML application for multimedia Hence all the advantages of XML - interoperability, internationalization, transformable, XML tools, etc. Hence all the advantages of XML - interoperability, internationalization, transformable, XML tools, etc. W3C recommendation W3C recommendation SMIL SMIL SMIL SMIL Allows the description of temporal and spatial coordination of one or more media objects. Allows the description of temporal and spatial coordination of one or more media objects. May be delivered locally or streamed over the Internet. May be delivered locally or streamed over the Internet. SMIL 2.0 is much more sophisticated than SMIL 1.0 SMIL 2.0 is much more sophisticated than SMIL 1.0 SMIL 1.0 spec is c. 30 pages SMIL 1.0 spec is c. 30 pages SMIL 2.0 spec is c. 540 pages SMIL 2.0 spec is c. 540 pages

SMIL 1.0 Deliberately simple language to: Deliberately simple language to: describe the temporal behavior of a presentation describe the temporal behavior of a presentation describe the layout of the presentation on a screen describe the layout of the presentation on a screen associate hyperlinks with media objects associate hyperlinks with media objects SMIL does not contain media content, it describes relations between media objects SMIL does not contain media content, it describes relations between media objects Clean separation between content and structure Clean separation between content and structure All the advantages of an XML application All the advantages of an XML application

SMIL 2.0 Extends the capability of SMIL 1.0 Extends the capability of SMIL 1.0 Sophisticated animation Sophisticated animation DOM compliance DOM compliance Incorporation of SMIL into other XML applications (eg XHTML+SIML) Incorporation of SMIL into other XML applications (eg XHTML+SIML) Incorporation of SVG Incorporation of SVG Advanced streaming capability (eg preload, download etc) Advanced streaming capability (eg preload, download etc) The SMIL 2.0 language is modular The SMIL 2.0 language is modular

SMIL 2.0 Modules Modules are parts of the language dealing with specific areas of functionality. Implementations do not need to deal with all modules. Modules are parts of the language dealing with specific areas of functionality. Implementations do not need to deal with all modules. Much easier to create specialist implementations Much easier to create specialist implementations Modules Modules Timing & Synchronisation (19 modules) Timing & Synchronisation (19 modules) Time manipulation (1 module - speed of media) Time manipulation (1 module - speed of media) Animation (2 modules - basic & spline) Animation (2 modules - basic & spline) Content control (4 modules for content selection and optimized delivery) Content control (4 modules for content selection and optimized delivery) Layout (4 modules) Layout (4 modules) Linking (3 modules) Linking (3 modules) Media objects (7 modules) Media objects (7 modules) Metainformation (1 module) Metainformation (1 module) Structure (1 module) Structure (1 module) Transition effects (3 modules - fades, wipes etc) Transition effects (3 modules - fades, wipes etc)

SMIL 2.0 Profiles Profiles are languages for a specific purpose that conform to the SMIL 2.0 specification. SMIL software implements specific profiles. Profiles are languages for a specific purpose that conform to the SMIL 2.0 specification. SMIL software implements specific profiles. Profiles consist of a selection of SMIL 2.0 modules, and may incorporate other XML applications. Profiles consist of a selection of SMIL 2.0 modules, and may incorporate other XML applications. SMIL 2.0 Language Profile SMIL 2.0 Language Profile Usually called SMIL, contains most of the features of the full SMIL 2.0 specification. Usually called SMIL, contains most of the features of the full SMIL 2.0 specification. SMIL 2.0 Basic Language Profile SMIL 2.0 Basic Language Profile Intended for mobile devices - PDA/Phone etc Intended for mobile devices - PDA/Phone etc XHTML+SMIL XHTML+SMIL Not a part of the SMIL 2.0 specification (it is a separate W3C project) - this adds timing features to XHTML. Not a part of the SMIL 2.0 specification (it is a separate W3C project) - this adds timing features to XHTML. SMIL for backwards compatibility SMIL for backwards compatibility

SMIL Implementations Real Networks Real Networks G2 Player implemented SMIL 1.0 G2 Player implemented SMIL 1.0 RealOne Player implements (most of) SMIL 2.0 language profile RealOne Player implements (most of) SMIL 2.0 language profile Proprietary extensions - RealPix and RealText Proprietary extensions - RealPix and RealText Microsoft Microsoft IE 6 implements XHTML+SMIL IE 6 implements XHTML+SMIL Apple Apple Quicktime 4.1+ supports SMIL 1.0 Quicktime 4.1+ supports SMIL 1.0 SOJA SOJA SMIL 1.0 implementation as a Java Applet SMIL 1.0 implementation as a Java Applet Oratrix products Oratrix products GRiNS Pro (full SMIL 2.0 language profile) authoring system GRiNS Pro (full SMIL 2.0 language profile) authoring system GRiNS Editor for RealOne GRiNS Editor for RealOne GRiNS Player (full SMIL 2.0 language profile) GRiNS Player (full SMIL 2.0 language profile) GRiNS Mobile Player (SMIL Basic language profile) GRiNS Mobile Player (SMIL Basic language profile)

Specifications for a SMIL presentation Content Content whole or partial media objects whole or partial media objects Spatial layout Spatial layout where do media items appear on screen? where do media items appear on screen? Temporal layout Temporal layout when do they appear? when do they appear? Alternative content Alternative content eg for different bandwidth, different purposes or different users eg for different bandwidth, different purposes or different users Links Links uses Xlink and Xpointer to provide sophisticated linking uses Xlink and Xpointer to provide sophisticated linking Metadata Metadata semantic information semantic information

Structure of a SMIL document element element Contains metadata and layout information Contains metadata and layout information element element Contains media objects and links Contains media objects and links<smil>... metadata... metadata... layout information... layout information... media objects, timing & links... media objects, timing & links

SMIL Media Objects Media object elements (generic) Media object elements (generic) Attributes Attributes src - the URI of the object src - the URI of the object type - MIME type type - MIME type name - for human readability name - for human readability Media type determined by file extension or type attribute Media type determined by file extension or type attribute Examples Examples Also brush elements Also brush elements paints directly onto screen paints directly onto screen

Temporal / Spatial Existence Text Text Space Space Time - has a duration, but does not change (ie is discrete) Time - has a duration, but does not change (ie is discrete) Image Image Space Space Time - has a duration, but is discrete (usually) Time - has a duration, but is discrete (usually) Video & Animation Video & Animation Space Space Time - has a duration and changes throughout that (ie continuous) Time - has a duration and changes throughout that (ie continuous) Audio Audio Does not exist in space Does not exist in space Time - has a duration and changes throughout that (ie continuous) Time - has a duration and changes throughout that (ie continuous)

Regions Used to define spatial existence Used to define spatial existence Regions are defined by X & Y coordinates (pixels or percentage of the window) and Z coordinate (stacking order - highest integer on top) Regions are defined by X & Y coordinates (pixels or percentage of the window) and Z coordinate (stacking order - highest integer on top) Regions all have a unique ID, and may overlap. Regions all have a unique ID, and may overlap. Regions are contained in the layout element, along with the root-layout which defines the window. Regions are contained in the layout element, along with the root-layout which defines the window.

Positioning of media in regions Regions may overlap or be nested (there is a hierarchy of regions - allowing media objects to be anchored together) Regions may overlap or be nested (there is a hierarchy of regions - allowing media objects to be anchored together) Media objects are placed in regions and positioned relative to them (top, bottom, left, right, height and width). Media objects are placed in regions and positioned relative to them (top, bottom, left, right, height and width). Clipping media objects Clipping media objects May or may not fill their region May or may not fill their region If they are re-sized the aspect ratio may or may not be preserved If they are re-sized the aspect ratio may or may not be preserved Slicing may or may not occur Slicing may or may not occur Scrolling may or may not occur Scrolling may or may not occur Layout is adaptable Layout is adaptable It can change to suite different devices or purposes It can change to suite different devices or purposes Examples Examples Computer vs handheld Computer vs handheld Movies with subtitles Movies with subtitles

Types of Time Media time Media time Time determined by media (eg frame rate of movie, or sampling rate of sound). Time determined by media (eg frame rate of movie, or sampling rate of sound). Document time Document time An object is displayed at a specified time after the document is loaded, for a specied duration. An object is displayed at a specified time after the document is loaded, for a specied duration. Run-time Run-time The timing is dependent upon data transfer over a network The timing is dependent upon data transfer over a network

Duration of Media Objects Intrinsic duration Intrinsic duration derived from media (eg the length of a video) derived from media (eg the length of a video) discrete media has an intrinsic duration of zero discrete media has an intrinsic duration of zero Explicit duration Explicit duration real time - dur attribute is specified in seconds or minutes real time - dur attribute is specified in seconds or minutes Examples: Examples: The repeat attribute may be set to an integer, or set as "indefinite" The repeat attribute may be set to an integer, or set as "indefinite" Paralell vs sequential playing Paralell vs sequential playing elements are played in paralell elements are played in paralell elements are played sequentially elements are played sequentially and elements may be nested and elements may be nested Start and end times can be absolute or relative to other elements Start and end times can be absolute or relative to other elements

Interaction in SMIL SMIL 2.0 responds to DOM events (eg onClick, onMouseOver etc) SMIL 2.0 responds to DOM events (eg onClick, onMouseOver etc) Any timing construct can be set to trigger by any event Any timing construct can be set to trigger by any event Other timing constructs include: Other timing constructs include: Animation (region placement changes over time) Animation (region placement changes over time) Transitions (standard library of transitions is accessed, and their speeds set) Transitions (standard library of transitions is accessed, and their speeds set) Manipulations (mostly media playback speed) Manipulations (mostly media playback speed) Test Attributes - Can deliver alternative content Test Attributes - Can deliver alternative content Language Language Data transfer rate Data transfer rate Screen size Screen size User preferences (eg text/image, closed captions on/off) User preferences (eg text/image, closed captions on/off)

Linking in SMIL Linking can be to other SMIL, or any other web content Linking can be to other SMIL, or any other web content element similar to that of HTML element similar to that of HTML element allows much more sophisticated linking from any spatial or temporal part of a document. element allows much more sophisticated linking from any spatial or temporal part of a document.

SMIL & SVG SMIL & SVG are complementary technologies. SMIL & SVG are complementary technologies. There is some element of overlap, but the emphasis is completely different. There is some element of overlap, but the emphasis is completely different. SVG is incorporated into SMIL 2.0. SVG is incorporated into SMIL 2.0. DOM provides the key to interactive interoperability. DOM provides the key to interactive interoperability. Adobe SVG Viewer is implemented as a RealOne plugin - thus SMIL can render SVG using it. Adobe SVG Viewer is implemented as a RealOne plugin - thus SMIL can render SVG using it.