U.S. patent application number 08/552648 was filed with the patent office on 2002-01-03 for computer controlled display system using a graphical replay device to control playback of temporal data representing collaborative activities.
Invention is credited to CHIU, PATRICK, KURTENBACH, GORDON P., MORAN, THOMAS P., VAN MELLE, WILLIAM J..
Application Number | 20020002562 08/552648 |
Document ID | / |
Family ID | 24206209 |
Filed Date | 2002-01-03 |
United States Patent
Application |
20020002562 |
Kind Code |
A1 |
MORAN, THOMAS P. ; et
al. |
January 3, 2002 |
COMPUTER CONTROLLED DISPLAY SYSTEM USING A GRAPHICAL REPLAY DEVICE
TO CONTROL PLAYBACK OF TEMPORAL DATA REPRESENTING COLLABORATIVE
ACTIVITIES
Abstract
A system for controlling the playback of a recorded session.
Timestream and event information for the session is captured by one
or more recording devices. Playback of a session is performed under
the control of a session access device. A session access device
utilizes event information to create a user interface for
controlling session replay. In the present invention, a window
acting as a player for playing back a timestream for a shared
representation media (e.g. an electronic whiteboard) is also used
for controlling playback of the session. Each graphical object in
the window is associated with one or more events (e.g. a creation
event, an editing event, a move event or a deletion event).
Selection of a graphical object enables playback time to be moved
to the time for one of the associated events. The selection made
may also be on an area of the window. This will enable the user to
view all events related to graphical objects in the selected area
(as some graphical objects may be erased or moved).
Inventors: |
MORAN, THOMAS P.; (PALO
ALTO, CA) ; VAN MELLE, WILLIAM J.; (LOS ALTOS,
CA) ; KURTENBACH, GORDON P.; (TORONTO, CA) ;
CHIU, PATRICK; (MENLO PARK, CA) |
Correspondence
Address: |
RONALD ZIBELLI
XEROX CORPORATION
ZEROX SQUARE 020
ROCHESTER
NY
14644
|
Family ID: |
24206209 |
Appl. No.: |
08/552648 |
Filed: |
November 3, 1995 |
Current U.S.
Class: |
715/203 ;
707/E17.009 |
Current CPC
Class: |
G06F 16/40 20190101 |
Class at
Publication: |
707/500 |
International
Class: |
G06F 015/00 |
Claims
1. A computer controlled display system for controlling the replay
of a session captured on a plurality of media capture devices,
wherein at least one of said plurality of media capture devices is
a shared representation media, said shared representation media for
creating and displaying graphical objects, said computer controlled
display system coupled to one or more players for replaying said
session, said computer controlled display system comprising: a
display; session input means for receiving temporal data of said
captured session, said temporal data comprising timestreams and
events; user input means for enabling a user to interact with said
computer controlled display system; synchronization means for
synchronizing playback of said session by said one or more players;
processing circuitry for generating display information from a
timestream representing operations performed on said shared
representation media, said display information for display in a
window on said display, said window operating as a player for
replaying the temporal sequence of operations performed on said
shared representation media, said replay causing one or more
graphical objects to be displayed in said window, and said window
further operating as a user interface for controlling the playback
of said session; window control circuitry for detecting a user
interaction on one or more graphical objects in said window and
generating a playback control signal to said synchronization means,
said playback control signal corresponding to said user
interaction.
2. The computer controlled display system as recited in claim 1
wherein said window operating as a player has an operating mode
that recreates the interactions with the shared representation
media in the same temporal sequence that they occurred.
3. The computer controlled display system as recited in claim 1
wherein said window operating as a player has an operating mode
that starts with an end state of the graphical objects on the
shared representation media and moves a cursor to point to the
graphical objects in the same temporal sequence that an event
occurred with respect to said marking
4. The computer controlled display system as recited in claim 3
wherein said visual representation of said cursor will change in
accordance with the event occurring with respect to a graphical
object pointed to.
5. The computer controlled display system as recited in claim 1
wherein one of said operations performed on said shared
representation is an erase operation for erasing graphical objects
and which are subsequently represented by a ghost graphical
object.
6. The computer controlled display system as recited in claim 1
wherein said window control circuitry further comprises: means for
identifying a graphical object that a cursor is pointing to; means
for identifying events associated with said pointed to graphical
object, said events having associated therewith a time said event
occurred in said session; means for determining which event to move
playback to; and wherein said playback control signal is one that
moves playback to the time associated with said determined
event.
7. The computer controlled display system as recited in claim 6
wherein said means for determining Which event to move playback to
is comprised of means for displaying a menu of all the events
associated with said graphical object and means for detecting an
event selected from said menu.
8. The computer controlled display system as recited in claim 1
wherein said window control circuitry further comprises: means for
identifying a graphical object that a cursor is pointing to; means
for identifying a creation event for said graphical object; and
said playback control signal is one that moves playback to the time
associated with said creation event.
9. In a computer controlled display system for controlling playback
of a session, a method for changing the playback time of said
session, said session captured on a plurality of media capture
devices, wherein at least one of said plurality of media capture
devices is a shared representation media, said shared
representation media for creating and displaying graphical objects,
said method comprising the steps of: a) analyzing a timestream of
said shared representation media to identify a plurality of events,
each of said plurality of events corresponding to an object created
on the shared representation media during said session, each of
said events having a corresponding a point in time in said session;
b) replaying said timestream of said shared representation media in
a window on a display coupled to said computer controlled display
system; c) detecting that a user has selected a graphical object in
said window, said graphical object representing a marking made on
said shared representation media; d) identifying events associated
with said graphical object; e) determining which of said events
will be used to more playback time to; and f) cueing players to
move playback of said session to the time associated with said
event determined in step e).
10. The method as recited in claim 9 wherein said step of replaying
a representation of said shared representation media in a window on
a display coupled to said computer controlled display system is
further comprised of the steps of: b1) displaying objects in said
window representing an end state of the shared representation media
at the end of said session; and b2) moving a cursor to point to an
object that is associated with an event during the playback of said
session.
11. The method as recited in claim 10 further comprising the step
of: b3) changing the visual representation of said cursor to
correspond to the type of event occurring on an object.
12. The method as recited in claim 9 wherein said step of replaying
said timestream of said shared representation media in a window on
a display coupled to said computer controlled display system is
further comprised of the step of displaying graphical objects in
said window in the temporal sequence that they were created.
13. The method as recited in claim 12 wherein said step of
replaying said timestream of said shared representation media in a
window on a display coupled to said computer controlled display
system is further comprised of the step of displaying a ghost
object at the spatial location where an object is deleted.
14. The method as recited in claim 9 wherein said step of
determining which of said events will be used to move playback time
to is further comprised of the steps of: e1)displaying a list of
events associated with said graphical object so that a user may
select one of said events; e2) detecting that a user has selected
one of the events in said list of events; and e3) providing said
selected event as said determined event.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is directly related to an invention
that is the subject matter of a concurrently filed, commonly
assigned U.S. patent application having the following serial
numbers and titles:
[0002] Ser. No. ______, entitled "Computer Controlled Display
System Using A Timeline To Control Playback Of Temporal Data
Representing Collaborative Activities", herein incorporated by
reference;
[0003] Ser. No. ______, entitled "System For The Capture and Replay
Of Temporal Data Representing Collaborative", herein incorporated
by reference;
[0004] Ser. No. ______, entitled "Computer Controlled Display
System Activities Using Correlated Graphical and Timeline
Interfaces For Controlling Replay Of Temporal Data Representing
Collaborative Activities", herein incorporated by reference.
FIELD OF THE INVENTION
[0005] The present invention is related to the field of multi-media
capture, replay and editing of sessions.
BACKGROUND OF THE INVENTION
[0006] Much of the work of groups, even in such orderly settings as
structured meetings, takes the form of casual interaction the give
and take of conversational exchanges whereby a group comes to a
shared understanding of the technical, process, and relational
facets of their work. This casual activity is poorly supported by
most computational tools, which tend to focus on the outcomes of
such activity, while ignoring much of how the group arrived at
those outcomes. Further, attempts to gather such information
typically end tip formalizing the activity, making the participants
conform to a way of working that suits the information gathering
tool rather than supporting their natural work practices.
[0007] Collecting audio, video, and computational recording of a
meeting provides a rich, reviewable record of group processes.
Unfortunately, the benefits of such a record has tended to be
unwieldy, oftentimes because of the required sequential access.
With the advent of digital recordings of such information the
ability to instantly access such information is possible. However,
instant access is only useful if you know where to go. Thus, it is
necessary and desirable to index such records based on meaningful
elements or events.
[0008] One approach to indexing is termed Real-Time notetaking,
where a person takes notes during the meeting using a system that
timestamps the various individual elements of the notes. This
provides a comprehensible index into the recording of the meeting.
By simply selecting any element of the notes, the system can
retrieve and play the part of the AV recording that corresponds to
the timestamp of the note element.
[0009] The simplest example is a textual transcription system, in
which the user simply types text as the meeting proceeds (the text
can be a literal transcription of what is being said or arbitrary
notes about the meeting). The notes consist of a string of text,
and the timestamped note elements are the individual characters of
the text. After the notetaking is complete, the user can select a
character and the corresponding part of the meeting recording will
be retrieved and played.
[0010] Notetaking systems allow users to construct a visual
representation (i.e. the notes), whose visible elements function as
indices into the meeting recording. Each index element has a time
associated with it, which is the time at which the user created it.
Since each index element is visible, the user can select it by
simply pointing to it and, since it has an associated time,
obtaining an address into the meeting recording.
[0011] Notetaking systems work fine as long as the construction of
the visual representation only consists of a sequence of element
creating events. Problems arise when the representation is allowed
to be edited during the course of the meeting, i.e. there are also
element-altering and element-deleting events. The source of the
problems is that the indices are the visible elements and not the
events.
[0012] A downside of the notetaking approach is that a person must
be devoted to the notetaking task. Thus, it would be desirable to
create an index into the meeting recording without dedicating a
person to the task of notetaking, and which is a by-product of the
natural meeting activity itself.
[0013] Related Works Include
[0014] Pedersen, E., K. McCall, T. Moran, and F. Halasz, "Tivoli:
An Electronic Whiteboard for Informal Workgroup Meetings",
Proceedings of the INTERCHI '93 Conference on Human Factors in
Computing Systems, pp. 391-389, April 1993 which describes an
electronic whiteboard application called Tivoli: The paper
describes the operation of Tivoli and the motivations for its
design. Several design issues are discussed including the need to
reconsider the basic assumptions behind the standard desktop
Graphical User Interface, the use of strokes as the fundamental
object in the system, the generalized wipe interface technique, the
use of meta-strokes as gestural commands.
[0015] Wolf, C., J. Rhyne, and L. Briggs, "Communications and
Information Retrieval with a Pen-based Meeting Support Tool",
Proceedings of the Conference on Computer-Supported Cooperative
Work, pp. 322-329, November 1992 which describes a system called
We-Met (Window Environment-Meeting Enhancement Tools) for
supporting communication and information retrieval needs of small
group meetings. We-Met runs on workstations with an attached
LCD/digitizing tablet over a local area network. We-Met provides a
shared drawing area in which the participants may each work in. The
shared drawing area is presented on the workstations. The reference
describes the results of a user study of We-Met in group settings
to better understand how it is used and a study that did not
involve We-Met conducted for the purpose of better understanding
how it can be used to facilitate information retrieval of recorded
meeting content.
[0016] EPO Publication 0 495 612 A2 entitled "A Data Access
System", Michael G. Lamming, published Jul. 22, 1992 describes a
note-taking system based on a notepad computer with an integrated
audio/video recorder. As the user types on the keyboard or writes
with the stylus or similar input instrument on the notepad
computer, each character or stroke that is input by the user is
invisibly time-stamped by the computer. This activity results in
the creation of meeting "notes". The audio/video stream is also
continuously time-stamped during recording. When playback is
desired, the meeting notes as finally created are presented to the
user. To play a section of recording back, the user selects part of
command. The computer then examines the time-stamp and "winds" the
record to the corresponding place in the audio/video recording,
where it starts playing --so that the user hears and/or sees what
was being recorded at the instant the selected text or strokes were
input. With a graphical user interface, the user may input key
"topic" words and subsequently place check marks by the appropriate
word as the conversation topic veers into that neighborhood.
SUMMARY
[0017] The present invention is directed to a user interface for
controlling playback of temporal data representing a collaborative
activity such as a meeting. Such temporal data is captured by one
or more capture devices (e.g. audio recordings or an electronic
whiteboard). Temporal data is comprised of timestreams and events.
Timestreams are sets of timestamped data which represent some
recordable aspect of the meeting. Audio and video recordings, or a
stored history of the actions on an electronic whiteboard are
examples of timestreams. Events are occurrences within a
timestream. For example, an event may be a particularly significant
action taken on the electronic whiteboard, or a change in speaker
during the session. Events are used to create indices which provide
direct access to a point or span in time during the collaborative
activity. Timestreams may inherently define events, or
alternatively, may be analyzed to identify events. Event
information is comprised of a timestamp, an event type and a list
of various properties of the instance of the event.
[0018] Playback of the temporal data is desirable to recall
conversations and/or other activities that occurred during the
meeting by both those present and by those who did not attend the
collaborative activity. The timestreams of a session are played
back contemporaneously. Such contemporaneous playback is desirable
since it best conveys the dynamics of the meeting.
[0019] Playback of a session is performed under the control of a
session access device. Coupled to the session access device are a
plurality of players for playing back timestreams. The session
access device utilizes event information to create a user interface
for controlling session replay. The user interface is comprised of
a plurality of windows. Each window may represent a player, a
playback controller or an editor (which would permit a user to
create additional timestream information). In the present
invention, a window acting as a player for playing back a
timestream for a shared representation media (e.g. the electronic
whiteboard) is also used for controlling playback of the session.
Each graphical object displayed in the window is associated with
one or more events (e.g. a creation event, an editing event, a move
event or a deletion event). Selection of a graphical object enables
playback time to be moved to the time for one of the associated
events. The selection made may also be on an area of the window.
This will enable the user to view all events related to markings
made in the selected area (as some markings may be erased or
moved).
BRIEF DESCRIPTION OF THE FIGURES
[0020] FIG. 1 is a block diagram of a system for capture and replay
of temporal data in the currently preferred embodiment of the
present invention.
[0021] FIG. 2 is a block diagram of a session access workstation as
may be utilized in the currently preferred embodiment of the
present invention.
[0022] FIG. 3 is a simplified pseudo-state of the operation of the
session access workstation of the currently preferred embodiment of
the present invention.
[0023] FIG. 4 is an illustration of a visual user interface of the
display coupled to a session access workstation in the currently
preferred embodiment of the present invention.
[0024] FIG. 5 is an illustration of a timeline user interface
display for a session in the currently preferred embodiment of the
present invention
[0025] FIG. 6 is a simplified illustration of a timeline interface
highlighting the relationship between the overview time track
display area and the focus time track display area.
[0026] FIG. 7 is an illustration showing the result of an operation
where the focus bar of FIG. 6 is stretched and the focus time track
display area scaled accordingly.
[0027] FIG. 8 is an illustration of the timeline user interface
display system for controlling playback of two sessions.
[0028] FIG. 9 is an illustration of a timeline interface wherein
two non-contiguous focus segments are presented in the overview
time track area and the focus time track area contains the detail
of each focus segment.
[0029] FIG. 10 is an illustration of a timeline interface showing
the result of re-sizing one of the focus time track areas of FIG.
9.
[0030] FIG. 11 is an example of a timeline interface for replay of
a session recorded with a plurality of capture devices, including a
Selection Track resulting from a selection operation on a LiveBoard
window.
[0031] FIG. 12 is further illustration of the timeline user
interface display showing the results of merging the audio tracks
of FIG. 11 onto a single track.
[0032] FIG. 13 is a further illustration of the timeline user
interface display of FIG. 11 showing the results of opening a note
on a note track.
[0033] FIG. 14 is an illustration of a meeting player for the same
session used to create the timeline user interface of FIG. 11.
[0034] FIG. 15 is an illustration of LiveBoard window in the
currently preferred embodiment of the present invention.
[0035] FIG. 16 is an illustration of correlation between the
LiveBoard window and the timeline interface, namely graphical
object to timeline indexing.
[0036] FIG. 17 is an illustration of correlation between the
LiveBoard window and the timeline interface, namely a synchronized
display state wherein both the LiveBoard window and the timeline
interface reflect the same instant in time.
[0037] FIG. 18 is an illustration of correlation between the
LiveBoard window and the timeline interface, namely temporal to
spatial indexing.
[0038] FIG. 19 is an illustration of correlation between the
LiveBoard window and the timeline interface, namely multiple events
per graphical object.
[0039] FIG. 20 is an illustration of correlation between the
LiveBoard window and the timeline interface, namely indexing by
location in the objects area.
[0040] FIGS. 21 and 22 provide an example of LiveBoard window
operating in the "bouncing-ball" playback mode before and after the
LiveBoard window has been edited.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0041] A portion of the disclosure of this patent document contains
material which is subject to copyright protection. The copyright
owner has no objection to the facsimile reproduction by anyone of
the patent document or the patent disclosure, as it appears in the
Patent and Trademark Office patent file or records, but otherwise
reserves all copyright rights whatsoever.
[0042] The present invention provides for the replay of records of
collaborative activities, such as meetings, and other
non-collaborative activities. While the currently preferred
embodiment is naturally described in the setting of a meeting, the
present invention is not limited to such activities.
Non-collaborative activities include presentations, speeches,
training sessions, and the like. Meetings amongst groups of people
are held for various reasons (e.g. brainstorming, project review,
etc.). Often, a participant, or some other designated person will
take "minutes" of the meeting to report the "output" or results of
the meeting. The creation of such minutes will typically require
that written notes be maintained. However, such written notes of
the meeting themselves may be incomplete, or may interfere with the
meeting itself. Other meeting artifacts (e.g. diagrams or lists)
are also created through use of some shared representation medium,
e.g. a whiteboard. In any event, it is often desirable to go back
and look at such notes and/or artifacts to prepare the minutes.
[0043] Another aid in creating meetings minutes is an audio or
video recording. Unfortunately, such recordings are purely
sequential and often very difficult to efficiently retrieve
information from.
[0044] An object of the present invention is to create indices into
the meeting recording of a collaborative activity that are a
natural by-product of the activity itself. This provides an
intuitive way for people to gain direct access to portions of the
recorded session. Events such as the change of a speaker, writing
on and manipulating markings on a whiteboard or the taking of a
note are examples of such natural by-products of a meeting that
provide useful index points.
[0045] A use of the present invention is to permit a person, either
an attendee or a non-attendee of the activity, to replay the
activity and add their own written or verbal comments. These
comments are created in the form of new events having a temporal
frame of reference identical to that of the original activity.
[0046] The present invention may be used to support collaborative
activities having different formats. One such format is where a
prepared agenda is presented and the collaborative activity
addresses the points on the agenda. The present invention may
support such a format by enabling the agenda to be "saved" in a
digital form, displaying the agenda during the course of the
activity and enabling annotations to be made on the displayed
agenda. Such annotations may subsequently be used as indices to the
record of the activity (e.g. if someone wanted to hear the
discussion about a particular agenda item discussed during the
activity). Another format is brainstorming. Here, a general topic
is discussed and through the synergy of the group, ideas are
generated. These ideas are typically written onto a shared medium
like a whiteboard for discussion. Later, a user may view a
"re-creation" of the writings on the whiteboard and use the
markings to go directly to points of interest.
[0047] The currently preferred embodiment of the present invention
is implemented on a computer controlled display system having a
Graphical User Interface (GUI) which allows multiple concurrent
"windows" to be displayed. A "window" refers to a visual
representation of an executing task. As will be described in
greater detail below, a window may be programmed to function as one
or more of a player, playback controller, or an editor. Windows and
operation thereof is well known in the art, so no further
discussion of windows or their operation is deemed necessary. Such
a GUI will also support operations such as "point and click" and
"drag and drop". A "point and click" operation is one where a
cursor on a display screen is positioned over a desired portion of
the display, such as an icon, using a cursor control device such as
a mouse or trackball. Once the cursor is appropriately positioned,
a button/switch associated with the cursor control device is
quickly depressed and released. This creates a signal which causes
a predetermined and context dependent operation to occur. Other
operations may require a "double click" where the button/switch is
depressed and released rapidly, twice in succession. A "drag and
drop" operation is one where the cursor is positioned on an object,
the button associated with cursor control device held down, and the
object moved or stretched until the button is released (or the
movement exceeds some predetermined boundary).
[0048] The system of the present invention is described with
reference to a software based timestream architecture and to a
systems architecture. The timestream architecture describes the
software framework in which the currently preferred embodiment is
implemented. The system architecture describes the functional
components of the present invention
[0049] Terms used in the description of the timestream and system
architecture are now defined.
[0050] Timestream refers to timestamped media data captured on a
capture device and which can be played back on a player.
[0051] Events are data representing an occurrence, e.g. a switch in
speakers or writing on a whiteboard, that happen at some point or
interval during an activity being captured.
[0052] Temporal Data refers to the combination of Timestreams and
Events.
[0053] Sessions are named collections of Temporal Data, which
represent coherently captured activities such as meetings.
[0054] Players are devices which can playback a timestream in its
original form or in a form which is indicative of the dynamics of
the timestream.
[0055] Editors refer to user interfaces through which changes may
be made to visual indicators or by which Events and timestreams may
be added to a session.
[0056] Playback Controllers refer to user interfaces through which
playback of a session is controlled.
[0057] Capture Devices are devices which capture and store temporal
data. Different types of capture devices will capture different
media (e.g. audio, video or writing on a whiteboard) of a
session.
[0058] Timestream Architecture
[0059] The timestream architecture supports the use of extensible
sets of tools for coordinated recording and playback. It is based
on a distributed object system that allows users to easily build
object which exist in one address space on a particular machine but
have "proxy" objects that exist in the same or different address
spaces on the same or other machines in a network is utilized. This
distributed objects system is termed Inter-Language Unification
(ILU) and is described by Janssen in "ILU Manual", Xerox Technical
Report, ISTL-CSA-94-01-02, January 1994. The basic data components
of the timestream architecture are Events, Timestreams and
Sessions.
[0060] Events consist of a start time, a duration (possibly zero
for `point` events), a type, and possible properties which may
depend upon the type. (For example a LiveBoard page event might
have `page-number` and `page-heading` properties.) The interface to
Event objects looks like this
1 TYPE Event = CLASS SUPERCLASS PersistentObject END METHODS
getType():String, getStartTime():Time, getDuration():Time END
[0061] The interface specifications described herein are in the
style of the specification language of ILU system described above,
but are not intended to be literal or exact, and should be easily
interpretable by one familiar with object oriented programming. The
meaning of datatypes String and Time are taken as self evident.
Additionally, as a subclass of PersistentObject, Events inherit the
methods
2 getPropertyNames():StringSequence setProperty(name:String,
value:String) getProperty(name:String):S- tring,
[0062] Events are created by calls to Session objects as described
below.
[0063] Timestream objects are used to reference stored data for a
given media type. Generally speaking the data associated with a
timestream allow time based access of the recorded media. Although
for many digital media, such as recorded audio, this consists of
time sampled data which could be treated as events, the high volume
and highly media (and even device) dependent interpretation of the
sampled data make it more practical to view the timestream as
`opaque`. That is, timestream data is normally manipulated only by
special tools related to the media and format of the timestream. In
particular, the data is created by a Recorder object and played
back by a Player object. Also, it may possibly be analyzed by media
specific tools to produce Events. (e.g. speaker segments,
silence/pause, scene change, etc.) Note also, that treating a
timestream object as opaque allows the architecture to accommodate
analog media. (e.g. the recorder and player might be a VCR under
computer software control, and the timestream might provide the
software with information about which tape should be used, and an
absolute time that should be associated with the beginning of the
tape.) The interface to Timestream objects looks as follows:
3 TYPE Timestream = CLASS SUPERCLASS PersistentObject END METHODS
mediaType():String, e.g. audio format():String, e.g. sun au
startTime():Time, duration():Time, END
[0064] Sessions are hierarchical collections which may contain
events, timestreams and other sessions. This use of the term
`Session` is broader than one sometimes encounters, and it should
be noted that a `Session` in the narrower sense of data associated
with say a given meeting or discussion, would be a special case.
Sessions are essentially a general purpose bookkeeping mechanism
for organizing Timestream data. The interface to Session objects
looks something like this
4 TYPE Session = CLASS SUPERCLASS PersistentObject END METHODS
getTimestreamByName(name:S- tring):Timestream,
getAllTimestreams():Timestream Sequence,
getSessionByName(name:Session):Session, getAllSessions():Session
Sequence, createEvent(start:Time, dur:Time, type String, props:
Property List):Event END
[0065] Players, Recorders and Media Servers
[0066] The timestreams architecture is extensible in the sense that
Player and Recorder objects share a common interface independent of
media type, and that no fixed set of supported media types is
assumed. A simplified interface to Player and Recorder objects
is:
5 TYPE Player = CLASS METHODS seek(t:Time), Change playback time to
t location():Time, Return current playback time play(s:Speed), Play
with speed factor s (1 = normal) stop(), Stop playing ...
attach(timestream:Timestream) Set player to play given timestream
END; TYPE Recorder = CLASS METHODS record(), pause(),
createRecording(session:Sessi- on, name:Name):Timestream,
finishRecording(), END;
[0067] Player and Recorder objects for a given media type are
implemented by a `MediaServer` associated with that media type. Of
course supporting a new media type requires the implementation of a
new MediaServer, but no change to the architecture (i.e. to the
interfaces necessary for creating or controlling recorders and
players) are required. This means that generic applications (e.g.
recording control programs or access and playback control programs)
can be written which will automatically support new media types, or
new implementations of service for existing media types. A
simplified description of the interface to MediaServer objects is
given by
6 TYPE MediaServer = CLASS METHODS getRecorder(format:String,
context:String):Recorder, getPlayer(format:String,
context:String):Player END
[0068] The context argument specifies information about the Player
or Recorder. For example, it could specify the host and device name
used for audio input/output.
[0069] Analyzers can be used to process the data associated with
one or more timestreams and produce events. Two such analyzers used
in the currently preferred embodiment are described below. A
simplified description of the interface to an analyzer is given
by
7 TYPE Analyzer = CLASS METHODS produceEvents(session:Session,
specs:String) END
[0070] The analyzer accesses the data in timestreams of the given
session, and creates events associated with the session. Which
types of timestream (e.g. audio, video, etc.) are accessed by the
analyzer depend on the type of analyzer. The `specs` argument
provides any necessary information about how the analysis is to be
performed. For example the analyzer might be an audio word spotter
which creates an event every time a given word (which would be part
of the specs string) is spoken. Note that the Analyzer could be
running after a session has been recorded, or in real time during
the recording process. In real time, the events produced by the
analyzer, can be `observed` by other processes (see event
notification described below) such as a process that implements a
user interface.
[0071] To further facilitate this extensibility, the architecture
provides a broker object which locates MediaServers appropriate for
supporting media of a specified type. The broker can also help
locate other kinds of objects such as analyzers. The brokers can
use information stored in shared network files to keep track of
which running processes implement a given object type (e.g. an
audio MediaServer), and/or of which programs must be run to create
those processes. Other network based name services could also be
used. A simplified description of the interface to a broker is
given by
8 TYPE Broker = CLASS METHODS
getMediaServer(media:String):MediaServer getAnalyzer(type:String-
):Analyzer END
[0072] Basic Control
[0073] Events, timestream and session data are stored in a
timestream database. Application programs using the timestream
database first obtain a timestream master object, which has methods
for creating or locating other objects. The master object may be
obtained from a timestream server running in another process
(perhaps on another host) through the same mechanisms as used by
Brokers described above. Alternatively, the program code which
implements the Timestreams server (and the master object) may be
included directly in an application process.
[0074] The basic steps necessary for a simple recording application
in pseudo code are:
9 . . . get top level timestream object called `master`. . .
session = master.getSessionByName(`Recordings`) broker =
master.getBroker() mserver = broker.getMediaServer(`audio`)
recorder = mserver.getRecorder(`mu law`, `default audio device`)
recorder.createRecording(session, `recording1`) recorder.record() .
. . some code which looks for user interface events indicating that
recording should be pauses, resumed, or completed. . . . call
routine to close recording recording.finishRecording() exit
[0075] The above pseudo-code fragment describes the steps needed to
create an audio recording named `recording1` in an existing session
called Recordings.
[0076] The pseudo-code necessary for playing back the recording
would be . . . get top level timestream object called `master`
[0077] session=master.getSessionByName(`Recordings`)
[0078] timestream=session.getTimestreamByName(`recording1`)
[0079] broker=master.getBroker( )
[0080] mserver=broker.getMediaServer(`audio`)
[0081] player=mserver.getPlayer(`mu law`, `default audio device`)
player.play(1)
[0082] . . . wait for user interface events indicating playback
should be stopped, or that a seek to a different time should be
called.
[0083] Confederations--Coordinated Playing and Recording
[0084] The timestreams architecture provides several mechanisms
which help applications coordinate with one another in general, and
which help coordinate control of multiple players and recorders in
particular. One mechanism is the Confederation object which is a
collection of Players and/or Recorders which act as a single Player
and/or Recorder. Players or Recorders may be dynamically added to
or removed from a confederation. A simplified description of the
interface to a Confederation is given by
10 TYPE Confederation = CLASS SUPERCLASSES Player, Recorder END
METHODS registerPlayer(player:Play- er),
unregisterPlayer(player:Player),
registerRecorder(recorder:Recorder), unregisterRecorder(recorder-
:Recorder), ... END
[0085] As a subclass of Player and Recorder, it is implied that a
Confederation supports the methods of those classes such as Play
and Record. The Confederation also supports additional methods
implementing such behaviors as the playing of sequences of time
ranges.
[0086] Using confederations, simplified code for setting up and
controlling playback of all media recorded for a session called
`ProjectMeeting#3` would look like
11 top level timestream object called `master` . . . session =
master.getSessionByName(`ProjectMeeting#3`) . . . broker =
master.getBroker() . . . conf = master.getConfederation(`xyz`) . .
. timestreams = session.getAllStreams() for each timestream in
timestreams do begin . . . mserver =
broker.getMediaServer(timestream.mediaType()) . . . player =
mserver.getPlayer(timestream.format(), `host1`) . . .
conf.registerPlayer(player) end conf.play() . . . . . .
[0087] wait for user interface events indicating how playback
should be controlled.
[0088] Note that the confederation is given the name `xyz`. Other
programs could get this confederation from the master object and
use it to control playback. This allows several programs running on
the same host, but perhaps with very different interfaces to
jointly control playback. Furthermore the same program as described
above, but running on a different host could create players
associated with that host, and register them with the `xyz`
configuration. The result would be a shared distributed playback
tool, requiring essentially no additional programming burden to
implement.
[0089] Event Notification--Interclient Communication
[0090] Another coordination mechanism is event notification. A
program can implement an EventNotifier, which is an object having a
method called `noticeEvent`. The notifier may be registered with a
session object, and then whenever an event is added to that
session, the noticeEvent method is called with the event as an
argument. For example when a selection is made of some objects in
on a LiveBoard Window, events can be created indicating times
associated with the selected objects, and a timeline interface with
a registered EventNotifier can be contacted (i.e. the noticeEvent
method called) allowing it to graphically indicate those times.
This example is described in greater detail below.
[0091] Synchronization
[0092] Synchronization issues arise at a variety of junctures and
in numerous forms. First, during capture, there is the need to keep
timestreams sufficiently aligned so that errors will not be
perceptually annoying during playback. In the case of audio and
video, this means that video and sounds must stay aligned to
approximately {fraction (1/30)} second (before annoying lip-sync
problems arise, for instance). Since the two timestreams may be
captured independently, on different machines, it is necessary to
use (or reconstruct) some common clock among the various sources.
In the currently preferred embodiment, when running fully
connected, the Network Time Protocol (NTP) described in RFC-1769 is
used among the distributed machines to keep the clocks accurate to
within milliseconds (this is an adaptive protocol and will usually
yield even better results by learning how to adapt to the machine's
drift, not simply by resynchronizing to a common standard).
Preferably, each quanta of a timestream's data would be timestamped
(as with the Real-Time Protocol packets used in the video), but
system assurances that the data will be sampled at a precise clock
rate is also adequate.
[0093] In other cases, e.g., textual annotations indexing other
media timestreams, requirements for such strict synchronization may
be relaxed. Again, the metric of needing sufficient accuracy that
any errors will not be annoying during playback is applied. For a
textual note, this means that the note must index the timestream at
a location sufficiently close to that which the user intended so
that the mark is a functional pointer to the recorded material. In
some circumstances, seconds of slop may be allowable, in others,
fractions of a second may be intolerable. If the user is running
NTP on the hardware that's running the annotation software, that
measure will generally provide sufficient accuracy. Other options
include making a call a time server to get the current time from an
NTP-equipped machine whenever an annotation is made, or synching
the clocks at the outset of the meeting to calculate an offset
between the annotation machine and NTP time. This last form of
correction may take the form of a special "synchronization
event"--one that is noted in (or can be analyzed out of) the data
of two or more of the distributed resources.
[0094] Almost regardless of the degree of precise synchronization
required, provisions can be made that will permit fully
disconnected operation of various capture devices. This is
desirable in cases where a recording is made in a setting where
connection (computational, audio, video, etc.) is undesirable or
impossible. Handheld computers or commercial camcorders are
acceptable capture devices, provided that means are provided for
eventually aligning the disparate clocks of the equipment. An
example of a technique to align a disconnected laptop with an audio
recording is to hit a laptop key noisily; this is an effective
synchronizing event. The keystroke is picked up by the laptop and
timestamped by its clock; the audio is analyzed to find the audio
event representing the key hit, this event being timestamped with
the audio recorder's clock. From this the offset between the the
clocks can be computed, and one of the sets of timestamps adjusted
to the other.
[0095] Drift (very low frequency errors) is also an issue during
recording sessions. Depending on the degree of accuracy needed in
sessions where independent clocks are employed, it may be necessary
to take readings at the start and end of the session to compensate
for systematic gains or losses or check the clock repeatedly for
offset corrections. Drift in those elements of the system that are
clocking themselves (e.g., an audio device running at a reported
8000 samples/sec that turns out to be 8057 samples/sec) may require
additional tweaking during playback, if data can be gathered to
suggest corrective action (e.g., play at 8057/8000 when normal
speed playback is desired).
[0096] Jitter (higher frequency errors) are generally handled by
buffering at appropriate places in the system.
[0097] Synchronization issues in timestreams playback sessions
(which often coincide with capture sessions, or may be sort of
"nested" in a capture setting) are closer to those typically dealt
With in multimedia systems.
[0098] To set context it is assumed that a variety of media
timestreams (audio, video, computing logs) have been captured and
are now charged with playing back all or a desired subset of those
timestreams in close synchrony so that a captured activity may be
re-experienced. It is further assumed that all of the records were
captured with perfect data, no drift, jitter, or offsets to
compensate for.
[0099] In the currently preferred embodiment the various timestream
players operate in a free-wheeling mode, using well-synchronized
and drift-free system clocks to stay reasonably closely
synchronized. This means that each player is responsible for
playing its timestream in a manner that matches the passage of
system time. In normal playback speed, this means that exactly one
second of playback (and system time passage) should occur for each
second of the original disk recording; faster and slower playback
rates simply represent more and less of the recording being played
back. Note that the best representation of these higher and lower
speed playbacks may be customized for a user's needs--high-speed,
pitch-preserved speech may be desired for skimming a meeting, or
quarter-second video clips chained together from appropriate
intervals might best convey very-high speed video playback.
[0100] Two aspects of using free-wheeling synchronization are
worthy of note--good startup and pause opportunity. The first is
simply that correct behavior of such an approach is dependent upon
the players all starting at the same time, regardless of
transmission time, buffering, etc. This means that the players
should honor the request for a scheduled start (e.g., initiate
playback at X system time (some small but adequate time (fractions
of seconds) into the future) at 100% normal speed of material
recorded at Y system time). This mode of startup assures a
coordinated start where subsequent real-time clock adherence will
produce the desired behavior. Pause opportunity simply means that
particular user actions give the players an additional opportunity
for minute synchronization corrections (e.g., declaring one player
to be the master and having all child players sync to it whenever
the user stops or pauses the playback).
[0101] System Architecture
[0102] A block diagram view of the hardware architecture of the
present invention is illustrated with reference to FIG. 1.
Referring to FIG. 1, a session start-up module 101 performs various
"housekeeping" functions in preparation for recording a session.
The session start-up module is preferably embodied as software
executing on a computer based system that is coupled to the various
recording components. Among its tasks, the Session start-up module
must make sure that session storage device 103 has enough available
storage capacity for storing the temporal data that is to be
created. This is accomplished by providing an estimate as to the
length of the session to be recorded and the number/types of
capture devices being used. The capture session start-up module 101
will also synchronize the start of "recording" by each of the
capture devices 102a-c. Each of the capture devices may commence
recording at the same or at different times.
[0103] The capture devices 102a-c capture the timestreams of the
various media and in some instances create events. The capture
device 102a generates timestream and event data 107. In the
currently preferred embodiment, an example of capture device 102a
is an electronic whiteboard such as the commercially available
LiveBoard TM product available from LiveWorks TM, a Xerox Company,
of San Jose, Calif. The timestream data being captured from the
LiveBoard is generated asynchronously as interactions occur. An
event may also be generated by invocation of a predetermined
function (e.g. changing a page on the LiveBoard.)
[0104] The capture device 102b generates a timestream 108. In such
a type of capture device, the capture device is continually in a
mode of capturing timestream data. Typical examples of capture
device 102b are video and audio recorders. Another example of such
a capture device 102b is a pointer. A pointer capture device is one
that captures the movement of a pointer, e.g. laser pointers that
are typically used during a presentation to point out something on
a projected slide or other visual. A pointer capture device is
particularly useful for formal presentations when the commonly
viewed material is prepared beforehand. The replay of a pointer
timestream would thus show the movements of the pointer during the
replay of a presentation.
[0105] The capture device 102c only generates events 109. An
example of the capture device 102c is a button. A button is a
device which causes the creation of an event in a button timestream
associated with a user operating the button. Button events may be
created by the user to indicate various activities such as the
beginning of a topic of interest, a particularly useful dialog or
the switching of a topic. Another example is a slide projector.
Events in a slide projector timestream would indicate the changing
of slides.
[0106] The capture devices 102a-b preferably capture the timestream
in a digital format. It is desirable to store the timestream in a
digital format to facilitate direct and random access to the
various carts of the timestream. However, it is within the scope of
the present invention to capture and store timestream data in an
analog format. The format of a timestream will correspond to the
capture device used to create the timestream. For example, an audio
timestream is comprised of a set of audio samples taken at some
regular interval, while a LiveBoard timestream is a history file of
timestamped primitive operations (described in more detail below).
Management of the captured timestream data is performed by various
Media Servers which can choose to store their data in whatever way
they deem most appropriate.
[0107] The created temporal data is stored in session storage
device 103. The session storage device 103 provides permanent
storage for different types of data: session data, event data, and
timestream data. The session storage device 103 is, in practice,
distributed over different physical storage devices and managed by
different components of the Timestream Architecture (described
below).
[0108] Also coupled to the session storage device 103 is a temporal
data analyzer 104. The temporal data analyzer 104 is a processing
means (e.g. a computer based system) that is used to analyze
temporal data 111 to identify events 110. The event information is
also stored in the session storage device 103.
[0109] Access to a recorded session is accomplished through a
session access workstation 105. This access may be over a network
(e.g. in a client-server architecture), or it could be through a
direct connection. Access session start-up module 109 performs the
various "housekeeping" functions necessary for replaying a session.
The functionality of the access session start-up module is
typically performed by the session access workstation 105. The
session access workstation 105 is typically a computer controlled
display system wherein control of session playback is accomplished
through a graphical user interface presented on a display. Such a
graphical user interface is described below. In the currently
preferred embodiment, the session access workstation is a SUN
SparcStation-10 running the Sun OS 4.1 operating system with an
X-Windows graphical user interface, available from SUN Microsystems
Inc., of Mountain View, Calif.
[0110] Further coupled to the session access workstation 105 are
players 106, playback controllers 107 and editors 108. Each of the
various players, playback controllers, and editors is integrated
within the session access workstation. So playback of an electronic
whiteboard timestream is accomplished through a first window on the
display of the workstation, a video timestream through a second
window on the display of the workstation and an audio timestream
via an audio subsystem of the workstation. However, it would be
apparent to one of skill in the art that the players need not be
integrated within a session access workstation, and may be discrete
playback devices. Further, in the currently preferred embodiment, a
single window may perform the function of a player, playback
controller and editor. The organization of windows and their
accompanying functionality in the currently preferred embodiment is
described in greater detail below with reference to FIG. 3.
[0111] Finally, new temporal data 112 created through use of an
editor is stored in session storage device 103.
[0112] LiveBoard Operation
[0113] The primary function of the LiveBoard in a collaborative
activity is to provide a "shared representation" which each user
can view and interact with. It should be noted that the LiveBoard
and its operating software are designed so that such a "shared
representation" need not be on a single LiveBoard device. Multiple
LiveBoards can be coupled together via networks such that the
actual collaborative activity may take place at different physical
locations.
[0114] The LiveBoard as used in the currently preferred embodiment
is not primarily intended to be a means for creating indices to the
session recording. However, as will be discussed in greater detail
below, the LiveBoard has unique capabilities which make it a useful
tool for controlling subsequent playback of a recorded session. The
LiveBoard operates under the control of the Tivoli application. The
Tivoli application is described in detail by Pedersen, E., K.
McCall, T. Moran, and F. Halasz in "Tivoli: An Electronic
Whiteboard for Informal Workgroup Meetings", Proceedings of the
INTERCHI '93 Conference on Human Factors in Computing Systems, pp.
391-389, April 1993. It should be noted that a version of the
Tivoli application is commercially available from LiveWorks under
the name Meeting Desk, for operation on a personal computer class
system.
[0115] Tivoli has a user interface that is similar to the class of
image creation programs known as "draw" programs. An example of a
draw program is MacDraw available from Claris Corporation of Santa
Clara, Calif. Draw programs create and manipulate images as
collections of graphical objects. Tivoli drawings are represented
as graphical objects. Graphical objects include:
[0116] strokes: "digital ink" objects created with a pen input
device
[0117] characters: created via keyboard or imported from text
files
[0118] images/icon objects: created by import or copying
[0119] structured objects: imported from databases
[0120] clocks: created with a clock gesture. Clocks are special
marks created on the LiveBoard that appear as a circular analog
clock face showing its creation time.
[0121] Tivoli maintains a history list of executed primitive
operations, e.g. add an object, delete an object, create an object,
change an object, select an object(s) or change a page. Every
primitive operation in the history list is timestamped and is
associated with an object. As will be described in greater detail
below, it is this history list that is analyzed to identify
events.
[0122] The graphical objects appearing on the LiveBoard may be
either made during the course of a meeting or loaded from some
memory media (e.g. a floppy disk) in a fashion similar to opening a
word-processing file on a personal computer. This latter instance
is particularly useful when the session is a formal
presentation.
[0123] Another important aspect of the operation of the LiveBoard
is the use of gestures. A gesture is an interaction with a
LiveBoard that is created like any other "inkstroke", but is
interpreted as a command (e.g. editing commands). For example, if a
particular object is to be "deleted", the objects are selected by
an encircling gesture with the pen and a delete command (e.g. a
pigtail gesture) invoked. After the deletion occurs, the marking
caused by the gesture no longer appears on the LiveBoard (however,
as will be described later, in the present invention a "ghost"
image may be retained when the session is replayed).
[0124] Further aspects of the Tivoli user interface are illustrated
below with respect to the LiveBoard Window.
[0125] Session Storage Device
[0126] As described above, the Session Storage Device is the
functional component of the Timestream Architecture that provides
permanent storage for different types of data: Session data, Event
data, and Timestream data. The Session Storage Device is, in
practice, distributed over different physical storage devices and
managed by different components of the Timestream Architecture. It
is most practical to divide up the Session Storage Device into a
Timestream Database (for Session and Event data) and Bulk
Timestream Storage (for Timestream data).
[0127] Bulk Timestream Storage is where the actual data of
Timestreams are stored and managed. In the case of video, this
consists of long, bulky sequences of digitized and compressed video
frames. In the Timestream Architecture, the management of
Timestream data is relegated to the various Media Servers, which
can choose to store their data in whatever way they deem most
appropriate. In the currently preferred embodiment, most of the
Media Servers store their data in ordinary Unix files; but Media
Servers for other storage mechanisms (e.g., a computer-controlled
VCR for analog storage of audio/video timestreams) have also been
implemented. It is even possible for a Media Server to use the
Timestream Database for its Timestream data, which may be the most
expedient mechanism for a Timestream with intermittent, low-bulk
data (e.g., the textual notes produced by a laptop computer).
[0128] The Timestream Database is a repository for storing and
retrieving Session and Event data, i.e., the data that organizes
all the information into Sessions and describes the constituents of
Sessions. The Timestream Database supports the user in locating a
desired Session, determining which Timestreams are associated with
that Session, and finding Events that are associated with the
Session and its Timestreams. The Timestream Database should not
onlv support the browsing of the Session data, but also a database
querying capability to allow selective retrieval of Sessions and
Events. Session and Event information must persist for months and
years, and thus must be stored on non-volatile devices (usually
disks). Since the Timestream Architecture is object-oriented, an
object-oriented database is appropriate as a persistent object
store for the Timestream Database. However, the timestream database
may also be implemented on top of a standard relational database.
In the currently preferred embodiment, the Timestream Database is
implemented on top of the Unix file system.
[0129] Analyzers
[0130] Temporal data analysis is particular to the information
captured by the timestream and the desirable events to be
extracted. In the case of a timestream of audio information, one
useful form of an event is knowing when a particular person is
speaking. Thus, it is desirable to analyze the audio stream to 1)
segment the timestream to indicate when different persons are
speaking, and 2) assign the various segments to the person
speaking. These segments would then represent events in the
timestream. Techniques for performing such an analysis on an audio
stream are described in co-pending applications Ser. No. 08/226,525
entitled "Unsupervised Speaker Clustering For Automatic Speaker
Indexing Of Recorded Audio Data", and Ser. No. 8/226,519 entitled
"Segmentation Of Audio Data For Indexing Of Conversational Speech
For Real-Time Or Postprocessing Applications", both of which are
assigned to the same assignee of the present application. In any
event, once such analysis is performed, the list of events for an
audio timestream will comprise a plurality of data items each
containing a timestamp, duration and speaker identifier.
[0131] In the case of analysis of a timestream captured by a
LiveBoard, an event may be the drawing of a figure or the writing
of a word, a page change, erasures of figures or words, annotations
made on existing markings, or the entering of a particular command
to the LiveBoard user interface. As described above, the LiveBoard
operates under the control of the Tivoli application. The
timestream generated by Tivoli is a history list of timestamped
primitive operations recorded in temporal order. The analysis of
such a timestream involves parsing the sequence of primitive
operations to identify significant events.
[0132] Each marking on the LiveBoard is referred to as an object.
Each object has one or more events associated with it. It is
fundamental to the present invention that all the events related to
an object are identified and provided to a user as an index into
the session. Accordingly, temporal data analysis in the present
invention identifies the various events on objects and stores the
events. For every object there is an object-creation event. The
object may also have object-altering events and an object-deletion
event. Further aspects of the LiveBoard timestream are discussed
below with respect to the LiveBoard window.
[0133] Session Access Workstation
[0134] In the currently preferred embodiment, the session access
workstation is a computer controlled display system operating under
the control of program instructions stored on a storage medium and
is described with reference to FIG. 2. Referring to FIG. 2, the
computer based system is comprised of a plurality of components
coupled via a bus 201. The bus 201 illustrated here is simplified
in order not to obscure the present invention. The bus 201 may
consist of a plurality of parallel buses (e.g. address, data and
status buses) as well as a hierarchy of buses (e.g. a processor
bus, a local bus and an I/O bus). In any event, the computer system
is further comprised of a processor 202 for executing instructions
provided via bus 201 from Internal memory 203 (note that the
Internal memory 203 is typically a combination of Random Access or
Read Only Memories). When in operation, program instructions for
carrying out the various functional components of the present
invention are stored in internal memory 203. The processor 202 and
Internal memory 203 may be discrete components or a single
integrated device such as an Application Specification Integrated
Circuit (ASIC) chip. The processor 202 and internal memory 203
comprise circuitry for performing the various processing functions
described herein.
[0135] Also coupled to the bus 201 are a keyboard 204 for entering
alphanumeric input, external storage 205 for storing data, a cursor
control device 206 for manipulating a cursor, and a display 207 for
displaying visual output. The keyboard 204 would typically be a
standard QWERTY keyboard but may also be a telephone like keypad.
The external storage 205 may be a fixed or removable magnetic or
optical disk drive. The cursor control device 206 will typically
have a button or switch associated with it to which the performance
of certain functions can be programmed. Further coupled to the bus
201 is audio output means 208. The audio output means 208 is
typically comprised of some audio signal generation means (e.g. a
Digital to Analog Converter) and a speaker. The audio output means
208 may also act as a player. Finally, coupled to the bus 201 is a
video output means 209. The video output means is typically a
commercially available processing means, e.g. a video board, for
enabling a video signal to be displayed on display 207.
[0136] While the session access workstation is embodied on a
computer based system operating pursuant to programmed instructions
stored on a storage medium, the present invention could be
practiced on any computer controlled display system, such as a
fixed function terminal or a LiveBoard.
[0137] The session access workstation operates using program
instructions for playback and control as described above with
reference to the timestream architecture. FIG. 3 is a simplified
state diagram illustrating the basic low-level operation of the
session access workstation. Referring to FIG. 3, the session access
workstation is initially in a start state 301 when a request to
playback a session is received. A session start-up state 302 is
then entered. During the session start-up state 302, the session or
sessions to be played back are selected by the user. The temporal
data of the selected sessions are retrieved and the various
players, controllers and editors are synchronized. Note that the
various players may be integrated into the same physical device as
the session access workstation, or they may be separate devices.
The various windows (i.e. players, playback controllers and
editors) are then displayed on the display coupled to the session
access workstation. At this point, what is termed an "operate"
state 303 is entered. The operate state 303 described here is used
to convey the notion that the session access workstation is
interactive and that the various functions of the user interface
for the session access workstation can be invoked at any time. In
any event, when the "operate" state 303 is initially entered, the
session is cued to playback the session from the beginning. While
in "operate" state 303 various primitive functions are performed
responsive to user input. Invocation of a "play" command or
equivalent graphical user interface input (e.g. clicking on a
particular icon) will cause playback of the session to commence
(box 304). This causes a playstate to be set to "play". Invocation
of a "stop" command will cause playback of the session to cease and
the playstate to be set to "stop" (box 305). Invocation of "display
modification" commands or controls while in a particular window
will cause the window to be modified (box 306). Such modifications
may be to change the tracks displayed in a timeline interface.
Invocation of playback controls will cause the playback point to
change (box 307). This will cause the replay of the session to be
cued at a new point. Invocation of edit commands will cause either
modifications to existing temporal data, or the creation of new
temporal data (box 308). Upon initiating the operations in the
various states, returning to the operate state 303 occurs.
[0138] It should be noted that multiple of such operations may be
invoked in order to accomplish a particular function on the session
access workstation. For example, an operation to select objects in
the LiveBoard window may invoke a "stop" followed by a "modify
display."
[0139] Finally, invocation of an "exit" command while in operate
state 303 will cause the access session to be halted (stop state
309).
[0140] Display of Session Access Workstation
[0141] FIG. 4 illustrates the screen display of the session access
workstation. The screen display of FIG. 4 shows a plurality of
windows that are open concurrently. As for most windows oriented
graphical user interfaces, the size and placement of the windows is
at the choice of the user. Referring to FIG. 4, what is
concurrently displayed is a LiveBoard Window 401, video window 402,
timeline interface window 403, notes windows 404-405, audio window
406, multi-media editor window 407 and meeting player window 408.
The LiveBoard window 401 may operate as a player, playback
controller or as an editor. As a player it is used to playback a
LiveBoard timestream. As a controller it enables control of the
replay of the session through interaction with objects displayed
therein (described in greater detail below). As an editor, a user
may create new objects or make specific annotations relating to the
session which may be displayed in subsequent replays of the
session.
[0142] The Video Window 402 is a player that is used to playback a
video timestream. Notes windows 404 and 405 are players used to
playback notes that may have been taken on a laptop computer, or
like device, that was enabled as a capture device during the course
of the meeting.
[0143] The Meeting player window 408 is a player and playback
controller. The meeting player window 408 provides a simulation of
the dynamics of the meeting as it is played back, using the events
of the various other temporal data. Playback is controlled though
interaction with various icons presented in the meeting player
window 408. The meeting player window is described in greater
detail below.
[0144] Audio window 406 is a controller used to control the replay
of the audio timestream, in particular the speaker volume for the
audio replay of the session.
[0145] Multi-media editor 407 is an editor that is used to create
notes, event or other information which may be introduced back into
the session as a timestream. Further, the multi-media editor 407
may be used to create multi-media documents that do not require the
session access workstation to be viewed.
[0146] The timeline interface window 403 is a playback controller.
The timeline interface window 403 embodies a temporal based view of
the events as they occurred during a session. The timeline
interface window 403 is described in greater detail below.
[0147] Timeline Interface
[0148] The timeline interface of the currently preferred embodiment
of the present invention provides playback control through
interaction with a representation of events along a timeline.
Events may be either of a fixed duration, or be open ended (wherein
only the creation time is of significance). During session
start-up, event data is loaded into the session access workstation.
The event data is used to create visual indicators that are scaled
on a timeline. These visual indicators may be used as index points
to move replay directly into corresponding time points of the
session. The internal structure for organizing the event data into
the timeline representation is now described.
[0149] The loaded event data is organized to give a user a simple
way to control the event data. This organization is defined by a
Type Map, an Event Menu and a Track Map. All event type have
hierarchic names called Htypes. For example:
[0150] Speaker/Adam
[0151] LiveBoard/Edit/Move
[0152] Button/Betty
[0153] Note/Laptop/Charlie.
[0154] A user defined Type Map is used for creating such Htypes.
The Type Map is a set of rules that takes the parameters of each
Event and produces an Htype. The set of Htypes are then arranged
into a simple hierarchic event menu that is presented to the user
in the label area of a time track area. All events may be displayed
to the user onto Tracks. The layout is defined by the Track Map.
The Track Map is a list of Tracks, each with a list of Htypes that
are represented on the corresponding Track.
[0155] Visual indicators are created for each of the Htypes. Visual
indicators can be of any graphical styles, but two general classes
of visual indicators are most commonly used. The first class is
termed segments. Segments are displayed on the timeline, as
rectangular boxes that are sized and scaled to correspond to the
duration over which the event occurs. The second class is termed
startpoints. These are displayed on the timeline as triangles whose
left edges are vertically positioned at the points in time that the
events began, and whose rights sides "point" to the right to
indicate that the activity corresponding to the events continue
indefinitely. For such events, there is no concern about the
duration of the event (e.g. an event indicating that a person is
beginning to take notes). Various operations may be performed with
respect to the Visual Indicators. Operations on Visual Indicators
include:
[0156] Create Visual Indicator (given type or Typed by default)
[0157] Select Visual Indicator(s)
[0158] Unselect Visual Indicator(s)
[0159] Move Visual Indicator to different Track (times stay
same)
[0160] Copy Visual Indicator to different Track (times stay
same)
[0161] View more information about Event represented by Visual
Indicator
[0162] Edit selected Visual Indicator's display parameters
[0163] Edit Visual Indicator times
[0164] Adjust Visual Indicator begin time
[0165] Adjust Visual Indicator (segment) end time
[0166] Adjust Visual Indicator time position
[0167] FIG. 5 illustrates the basic areas in the timeline window.
Referring to FIG. 5, the timeline window 501 is comprised of a
plurality of display areas. An overview time track area 502 is used
to provide an overview of the session, and a focus time track area
503 provides more detailed information over a duration less than or
equal to the entire session. It should be noted that operation of
each of the track areas can provide the same type of temporal
information. The difference is the scale which the information is
intended to detail (i.e. the entire session versus a portion of the
session).
[0168] Defined within overview time track area 502 is clock area
512 and defined within focus time track area 503 is clock area 513.
Each of the clock areas 512 and 513 present the clock times and
tick marks to indicate the time span and scale of the corresponding
time track area. The overview time track area 502 has defined
within it a special track termed the focus track 508. Lying on the
focus track 508 is a focus segment 509. The focus segment 509
corresponds to a duration of the session detailed in the focus time
track area 503. Further associated with each time track area is a
label area. Each label area is for identifying the "tracks" which
are displayed in the corresponding time track area. The label area
504 corresponds to the overview time track area 502 and the label
area 505 corresponds to the focus time track area 503. The
relationship between the overview time track area 502 and the focus
time track area 503 is indicated in focus area 507. This
relationship is made visually apparent by arms 510 and 511 which
extend from the ends of the focus segment 509 to the ends of the
focus time track area 503.
[0169] Also illustrated in FIG. 5 is a button area 506. The button
area 506 is a static area that contains "soft" buttons for invoking
various playback control functions. Such buttons are invoked by
using a cursor control device in a point and click fashion. The
arrangement and functions of the buttons is exemplary and is
intended to provide simple access to specific commonly used
functions.
[0170] The button 520 is used to cause playback to skip back in
time 10 seconds and the button 521 causes playback to skip forward
in time 10 seconds. The directional arrows in button group 522
provide for context sensitive movement or scrolling. The button 523
provides for stopping the replay of the session. The button 524
initiates the playing of the session. The button 525 permits
skipping to next events on a selected track or set of selected
tracks. The button 526 provides for entering an Edit mode to modify
the timeline interface or the visual indicators displayed thereon.
The button group 527 provides for context sensitive deleting or
copying (e.g. copy or delete a visual indicator). The button group
528 provides for context sensitive expand and collapse (e.g.
collapse a set of tracks into a single track, or expand a collapsed
set of tracks) The button 529 is used to display a session menu.
The session menu enables the user to load data for sessions, save
sessions or quit sessions.
[0171] As noted above, the portion of the session being shown in
the focus time track display area is indicated by a focus segment
contained on a focus track of the overview time track area. In
order to change the span of focus in the focus time track area, the
focus segment is re-sized by the user. This is illustrated in FIGS.
6-7. In FIG. 6, the focus segment 601 indicates a portion of the
session that is shown in focus time track area 602. Other visual
cues identifying this relationship include the changes to the
respective clock areas 603 and 604, namely the re-sizing of tick
marks and the respective beginning and end times for the time track
areas, and the relative positioning of the time indicators 605 and
606. Also, indicated in FIG. 6 is playback time indicator 607 which
indicates the current playback time.
[0172] Re-sizing the focus segment is accomplished by various
cursor control operations. In the currently preferred embodiment, a
button depressed on the mouse while the cursor is positioned on the
right edge of the focus segment causes the focus segment to be
stretched in the direction of movement of the cursor. The left side
of the focus segment is manipulated in the same manner.
[0173] FIG. 7 is an illustration of the result of the right side of
the focus segment 701 having been stretched to the right to
increase the span shown in the focus time track area. This
increased span is also reflected by changes in the clock areas 702
and 703 (re-scaling of tick marks and a change in the end time for
the focus time track area.)
[0174] The timeline interface can be used to control playback of
multiple sessions or to focus on multiple spans of a single
session. FIG. 8 is an illustration of a timeline interface for two
sessions. The two sessions may represent the morning half and
afternoon half of an all-day meeting. Or they may represent
different occurrences of a regularly scheduled meeting such as a
weekly project review meeting. Typically, the two sessions will
have some commonality. Referring to FIG. 8, the timeline interface
window 801 is comprised of two overview time track areas 802 and
803 and corresponding focus time track areas 804 and 805. Focus
segment 806 indicates a span in the session corresponding to
overview time track area 802 and the detail for that span in focus
time track area 804. Similarly, focus segment 807 indicates a span
in the session corresponding to overview time track area 803 and
the detail for that span in focus time track area 805. The actual
tracks show in the respective focus time track areas 804 and 805
need not be the same. If they are different, separate label areas
would be needed. This may be undesirable as taking up too much
space in the display area.
[0175] FIG. 9 is a further illustration that indicates that the
detail of multiple spans of a single session may be displayed in
the focus time track area. This causes multiple focus segments to
be displayed on the focus track of the overview time track area.
Referring to FIG. 9, a first focus segment 901 has detail shown in
a corresponding area 903 in the focus time track area while a
second focus segment 902 has a corresponding area 904 in the focus
time track area. Such a display may be desirable when it has been
determined that there are certain areas where there is no interest
in replaying (e.g. if you know beforehand that you only want to
review discussion relating to particular pages on the LiveBoard).
By default, the focus time track area will be divided evenly
between the two focus segments and be on the same scale. However,
as illustrated in FIG. 10, the portion of the focus time track
display allocated to a session duration can be modified. Here, the
area 904 of FIG. 9 has been increased to the area 1001 of FIG. 10,
and the area 903 of FIG. 9 has been decreased to area 1002 of FIG.
10. This increase of size may be performed by a drag operation
moving the left side of the area 904 to the left.
[0176] FIGS. 11-14 illustrate variations on a timeline interface
display for a system comprising the following capture devices: a
LiveBoard, an audio recorder, two user taking notes on personal
computers, a video recorder and a button for each user. Of course,
other combinations of capture devices may be utilized or events
from some capture devices may be omitted, which would result in a
different timeline interface display. The session attendees for
this example are named Adam, Betty and Charlie.
[0177] Referring to FIG. 11, overview time track area 1101 displays
information for the entire session and has a focus segment
indicating the entire session. Thus, focus time track area 1102
displays the detail of the entire session. Playback indicators 1113
and 1114 indicate the current playback location within their
respective time duration's.
[0178] Further associated with the session area 1101 is session
identifier 1103. The session identifier identifies the session
being played back.
[0179] Information provided related to the overview session time
track area, and thus the entire session includes the session start
time 1104, and the session end time 1105. Each of the session start
time 1104 and session end time 1105 may indicate the actual time of
day that the session occurred or be relative to a session start
time of 0:0:0 (as illustrated in FIG. 11).
[0180] Information related to the focus time track area 1102
includes the span start time 1106 and the span end time 1107. Each
of the span start time 1134 and span end time 1135 may be in terms
of the actual time of day of the particular span, or be relative to
a session start time of 0.
[0181] The focus time track area 1102 includes a track label
section 1111 for providing information about what each track
represents. Tracks 1117 and 1118 indicate editing events performed
on the LiveBoard. Track 1118 is generated responsive to a selection
operation performed in the LiveBoard window and is described in
greater detail below. The track 1117 indicates various editing
operations performed on objects on the LiveBoard. On track 1117,
each editing operation has a unique color coded visual indicator.
So the color red may represent the deletion of an object, the color
green the addition of an object and the color blue the movement of
an object.
[0182] Tracks 1119-1121 indicate audio events. The track 1119
indicates segments where "Adam" is speaking, the track 1120
indicates segments where "Betty" is speaking, and the track 1121
indicates segments where "Charlie" is speaking. Each of the visual
indicators of segments when a participant is speaking is visually
distinct (typically by color or texturing).
[0183] Tracks 1122-1123 indicate the start point of notes that were
taken by meeting participants Adam and Charlie. The notes were
taken on a personal computer or other text creation device that is
operating as a capture device.
[0184] Track 1124 indicates instances of the event of "button"
pressing. Each meeting participant has a button that may be
depressed when the participant feels that something significant is
being discussed. Again, the visual indicators are color coded to
identify the person who depressed the button. So for example blue
indicates Betty depressed her button and green indicates that
Charlie depressed his button.
[0185] Track 1125 indicates instances of events relating to the
video timestream. Such events may include a person standing to
speak, or some type of gesturing with respect to a whiteboard. Such
events would be identified through analysis of the video
timestream.
[0186] As described above, the selection track 1118 is
automatically generated as a result of a selection interaction in
the LiveBoard window. The selection interaction is one where
various objects (e.g. words, or diagrams) that are displayed on the
LiveBoard are selected. Events relating to the selected object(s)
are then displayed on the timeline window. It should also be noted
that selection may occur with respect to a spatial area. In such a
selection, an area is selected and events for objects that were
located in the selected area are displayed on the timeline. This
would be particularly useful to replay portions of a session where
markings were erased from the LiveBoard (e.g. during the process of
replaying, a skip is made and it is noticed that an object has been
erased, or it has been replaced with another object.) Referring
back to FIG. 11, various selection events are illustrated. Again,
preferably the visual indicators are color coded to indicate the
type of event. A creation event 1127 indicates a point in time
where an object was created, a move event 1128 indicates the point
in time where the object was moved on the LiveBoard, a change color
event 1129 indicates that the object color was changed, and a
delete event 1130 indicates that the object was deleted.
[0187] The content of each of the time track areas is user
modifiable. Tracks may be merged, added, hidden or moved. In order
to modify the contents of a time track area operations are
performed within the corresponding label section. For example, with
reference to FIG. 11 the audio tracks 1119-1121 may be selected and
merged. The results of such merged tracks is illustrated in FIG.
12, where merged track 1201 has been created. Selection of tracks
may be accomplished by operating the cursor control device by
depressing a switch associated with the cursor control device and
moving the cursor in a manner such that it passes over the labels
of the track. Indication of selection of labels is accomplished
through some visual stimulus such as presenting the selected labels
in a reverse video mode. Confirmation of selected labels is
accomplished by releasing the switch. At this point various track
operation options may be presented. The user would then select the
desired operation (in this case a merge operation). This is but one
way in which track display operations could be performed. Other
techniques could be invocation through pull down menus or through
commands entered on a command line.
[0188] Operations on Tracks include:
[0189] Select Track(s)
[0190] Unselect Track(s)
[0191] Create Track (given Htypes)
[0192] Reposition selected Track
[0193] Delete selected Track(s)
[0194] Collapse selected Tracks (into one Track)
[0195] Expand selected Track (into a sequence of Tracks based on
its Htypes)
[0196] Edit Display Parameters of selected Track(s)
[0197] Edit Track Label
[0198] A point and click operation on the different visual
indicators may cause different things to occur. In each case, the
subsequent playback of the timestreams will be set to the time
corresponding to the beginning of the visual indicator. In the case
of Notes, a window containing the text in the note is opened. The
occurrence of such an operation is illustrated in FIG. 13.
Referring to FIG. 13, the visual indicator 1301 has been pointed to
and the switch on the cursor control device clicked. This causes a
text window 1302 to be opened containing the text generated during
the meeting (here the text "Good Point Made By Betty. Need to Use
that Argument in Meeting With the Boss"). It should be noted that
the text window may also be presented in a different location
outside the time track display area.
[0199] It should be noted that the timeline may be displayed with a
vertical or horizontal orientation, or used in combination with
other visualization techniques for showing long strings of
sequenced data.
[0200] Meeting Player/Controller
[0201] The form of a player is not limited to playback of the
temporal data of a session in the exact same form as it was
created. An example of such a player is the meeting player. A
meeting player is used to visually represent various meeting
dynamics. This may be useful for example when a person may not be
able to recognize the voices being replayed, but wishes to identify
the speaker. The meeting player of the present invention simulates
the activities as they are taking place during the meeting. FIG. 14
illustrates a window 1400 displaying a meeting player. Referring to
FIG. 14, the meeting contains visual indicators 1401-1403 each
representing a meeting participant, visual indicators 1404 and 1405
represent note taking devices (e.g. laptop computers) and the
visual indicators 1406-1408 represent "buttons". During play back,
the icons representing current events that are occurring are
highlighted. Here, the icon 1401 is highlighted so the speaker
represented by icon 1401 is speaking. Likewise, when someone
presses a button, the corresponding button icon would be displayed
as highlighted.
[0202] Note that it would be possible to include within the speaker
icon a thumbnail image of the speaker. It may also be desirable
that each of the associated icons may maintain the same visual
characteristic as the corresponding track on the timeline. So if
the speaker icon 1401, button icon 1406, and personal computer icon
1404 Were associated with Adam, who had a visual characteristic of
blue, these icons would be blue. However, it is recognized that
there may be situations where this would not be possible due to
limitations in the number of displayable colors or other
factors.
[0203] Further displayed in the meeting player window are a
LiveBoard page and title indicator 1410 and a clock 1411. The page
and title indicator 1410 indicates the "page" that is currently
being viewed on the LiveBoard at this instant of the playback. The
clock 1411 indicates the playback time. A table 1409 is also
displayed to provide a visual cue as to the fact that the session
represents a meeting.
[0204] The meeting player may also be used to change playback to a
different speaker. This enables the user to easily traverse the
meeting by a particular speaker. Switching to the different
speakers is accomplished by a "point and click" operation on the
icon of the desired speaker. This will cause the playback to jump
to the next point in time for the selected speaker. Moreover, this
operation may work for any icon, where a jump to the next instance
of an event associated with the selected icon is made (e.g. the
Page and title indicator 1410 could be subject to a "point and
click" operation to skip the replay to the beginning of the next
page of the LiveBoard). Thus, the meeting player in this instance
further operates to control playback of the session.
[0205] The meeting player may be designed to indicate various other
events that can be analyzed. For example, a "laughter" icon 1412 or
"applause" icon 1413 can be provided to indicate when laughter or
applause is occurring, or to skip to a next temporal occurrence of
laughter or applause. Further, while the preferred embodiment is
used to represent a meeting, other types of activities, e.g.
presentations, could be represented in a similar fashion.
[0206] LiveBoard Window
[0207] The LiveBoard Window of the currently preferred embodiment
simultaneously operates as a player of the LiveBoard timestream, a
playback controller, and an editor. The LiveBoard window is based
on the aforementioned Tivoli software. The LiveBoard window
operates in different playback modes: an animated mode
reconstructing the exact appearance of a past state, a
"bouncing-ball" mode, where a cursor points to the area where
marking/editing is happening and a "null" mode. In the animated
mode, the LiveBoard window replays the LiveBoard timestream (i.e.
the timestamped history list), in the sequence recorded. In the
"bouncing-ball" mode, the state of the LiveBoard at the end of the
session (or end state of a page) is displayed and as events related
to objects occur, the objects are highlighted and pointed to by the
cursor. In the "bouncing-ball" mode the shape of the cursor changes
to indicate the type of event (e.g. a pen for creating the object;
a hand for moving the object; an eraser for deleting the object).
In the "null" mode the end state of the LiveBoard at the end of a
session (or end state of a page) is displayed. The null mode is
used when updating of the LiveBoard window is undesirable (e.g. it
would be distracting to the user).
[0208] In each playback mode, an additional feature called ghosts
leaves a faint version of an object (its ghost) on the display even
after it is deleted. This feature can be turned on or off by the
user. A ghost object can be used as an index into the session.
[0209] The animation mode and bouncing-ball mode each indicate the
type of event occurring at a particular time. In bouncing ball
mode, the cursor tells the type of event, whereas in full animation
mode the animation shows the type of event by how it is
animated.
[0210] Playback control occurs through interaction with the objects
displayed during playback. As a simple example, a user may select
an object and invoke a play command directly on the LiveBoard to
cause immediate playback at the most significant event relating to
the phrase (e.g. the time it was written on the LiveBoard). Other
playback control features are described below.
[0211] The LiveBoard window may be operated as an editor because
all the LiveBoard functionality is available. So a user may perform
their own manipulation of the objects displayed, or add to the
drawings. Such manipulations will generate their own
timestream.
[0212] It is significant that the LiveBoard window operates as both
a player and a playback controller. As opposed to known notetaking
systems, the LiveBoard window provides a playback control means
which is not strictly based on the end state of the notetaking
medium. A user may interact with the LiveBoard at any point during
the playback. So for example, a user may be replaying the session
and skip ahead to a point in the session (e.g. by a point and click
operation on a clock) and notices that a word was erased from the
LiveBoard. This could trigger a user to review the portion of the
playback related to the erasure of the word in greater detail.
[0213] FIG. 15 illustrates the LiveBoard Window of the currently
preferred embodiment "Copyright 1991-1995 Xerox Corporation" 17
U.S.C. 401). Referring to FIG. 15, the LiveBoard Window 1501 is an
instance of the user interface for the Tivoli application running
on the session access workstation. The LiveBoard Window is
comprised of a controls area 1502 which borders an objects area
1503 on two sides. The various controls in the controls area 1502
are active in the LiveBoard Window 1501. It is the markings
displayed in the objects area 1503 which are active and selectable
objects. Also illustrated is a Playback Tool 1504. The Playback
Tool 1504 is used to initiate playback at a point relevant to a
selected object.
[0214] The example of an interaction with the LiveBoard to select
an object and listen to its earliest point is possible because of
the created history list. As described above, the history list is a
listing of primitive operations performed and each primitive
operation is timestamped and associated with an object. The object
is typically defined spatially and as the function performed. For
example, draw a line from point X1, Y1 to X2, Y2. So when a
selection of an object is made, it is a simple matter of looking at
the spatial location, finding the objects at that location, finding
the primitive objects associated with the objects and then choosing
the time of the most salient event. In the general case, the most
salient event will be the "creation" event. However, other times
may be interesting to the user so a selection operation is provided
which enables as user to select the most salient event (described
below).
[0215] LiveBoard timestreams can be generally categorized into 2
types: monotonic and non-monotonic. A monotonic timestream has
primarily "create" events. The only thing that happens is that new
objects are created (no moves, changes or erases). In a monotonic
timestream, the overwhelming majority of objects have just one
event associated with it (its creation event).
[0216] A non-monotonic timestream is comprised of creation, change,
move and delete events. Thus, each object can have more than one
event associated with it. It is useful to distinguish changes that
change the positions of objects (i.e., moves) and those that don't.
If a timestream does not have any position-changing events, then
each object has a unique position on the display. If there are
movement events, then an object may occupy multiple positions
during the session. Finally, if a timestream has deletion events,
then the objects may disappear at some time during the session.
[0217] The LiveBoard window may be used as a playback controller
stand-alone or in correlation with the Timeline interface. The
correlation with the Timeline interface is described below. In
standalone mode, for a monotonic timestream selection of an object
and invocation of the playtool w ill cause replay at the time of
the "creation" event for the object (since this is the only event
related to the object).
[0218] In the case of non-monotonic timestreams, the issue is what
"event" to use to commence playback time for a selected object.
When the user points to an object with the Playback tool, the
system plays the session at the time of the earliest event
associated with the object. However, other times for an object
might be significant, e.g., the times at which an object was moved
might be important. There are alternative ways to access other
event times for an object. For example, an event menu may be
provided which lists all the events associated with the object. The
user just selects the event desired and playback would commence at
the time associated with the event.
[0219] Another technique is to use a play-next-event button, which
skips the playback time to the next event associated with the
current object. Yet another technique using timeline correlation is
described below.
[0220] Clocks
[0221] The notion of clocks on a LiveBoard and in the LiveBoard
window were described above. A clock is useful in replaying the
session in that it provides a temporal reference of when activities
took place in the LiveBoard window. Recall that clocks are
graphical objects created by a clock gesture. Clocks may be
manipulated and edited in the same fashion as all graphical
objects. But a clock object is special: it contains a special
property in its data structure that represents its own private
"internal" time. When a playback tool touches a clock, the play
point is set to the clock's internal time, not to the time of some
event associated with the clock (e.g. its creation time). Thus, the
clock can be used to deal with time independently of its own
history. By default the clock's internal time is the same time as
the creation operation for the clock. But it doesn't have to be,
and this leads to various useful functions.
[0222] The clock's internal time may be altered. In the currently
preferred embodiment, when an edit gesture (currently, point and
hold) is made on a clock, a menu pops up which allows the user to
change the clock's internal time. These change can be either
relative (e.g. move the internal time forward or backward by N
seconds) or absolute (i.e. change the internal time to a specified
time T). The former is most useful, because it allows a clock's
internal time to be adjusted slightly to be more accurate for
indexing.
[0223] For example, in a meeting an interesting issue is raised and
discussed. A user at the LiveBoard can index this discussion by
creating a clock and writing a note. But usually the clock will be
created somewhat after the discussion began. Thus the clock can be
edited to adjust its time backwards a bit to more accurately index
the start of the discussion. This edit can be made during the
meeting or later during an access session. The latter is most
useful, because it is convenient to replay the meeting from the
current clock setting to determine if the setting is accurate. In
the current implementation, this is made convenient for the user by
having replay commence automatically after an edit is made, giving
the user immediate feedback on the appropriateness of the time
setting.
[0224] Users can create clocks during an access session by adding
them via the LiveBoard window (see the LiveBoard Window as an
Editor below). But in this situation the internal time of the clock
is set to the current playpoint of the playback tools, not to it's
creation time in the access session (which is not at all useful).
For example, consider a user accessing an earlier meeting. He
listens to the audio of the meeting and hears an important idea
that was not indexed during the meeting. So at this point in the
playback he creates a clock and then types a note next to it. This
clock is a new index into the meeting. Thus the quality and
quantity of indexing can be enhanced at access time by being able
to create objects that hold times in the original meeting.
[0225] LiveBoard and Timeline Correlation
[0226] It is often desirable to view all the events associated with
an object. For example, a user may wish to know when and if an
object was altered or deleted. As described above, all the events
associated with an object selected in the LiveBoard are displayed
on a selection track of the Timeline interface. This provides a
means for displaying user specified relevant indices into a session
through correlation between the LiveBoard and Timeline
interfaces.
[0227] Other features of the correlation through interaction with
the LiveBoard Window are illustrated in the following scenario
described with reference to FIGS. 16-20. It should be noted that
the representation of the LiveBoard Window and the timeline
interface have been simplified. In particular, the control areas on
the LiveBoard window and the overview time track area of the
timeline interface are not shown in the Figures.
[0228] Graphical Object to Timeline Indexing.
[0229] Referring to FIG. 16, the user sees a word in the LiveBoard
Window 1601 and wants to replay the conversation when this word was
written. The user selects the word 1602 "redundancy" utilizing a
suitable selection technique (here by circling the word with a
gesture using the pen/mouse). The timeline interface 1603 is then
updated on the Select track to show all events related to the
selected word. Here, the visual indicator 1604 is displayed on
select track 1605. The visual indicator 1604 represents the event
of writing the word. In this instance, no other events are
associated with the word "redundancy".
[0230] Also illustrated in the timeline interface 1603 is playback
time indicator 1606. So it is noted that at this time, the playback
is at a point "after" the word "redundancy" has been written.
[0231] Synchronous Display State
[0232] FIG. 17 illustrates the synchronization between the
LiveBoard Window and the timeline interface. The user moves
playback time indicator 1703 in the timeline interface 1702 just
before the visual indicator 1604. The LiveBoard window 1701 is then
updated to display what was on the LiveBoard at that instant in
time. In particular it is noted that when compared to FIG. 16, the
word "redundancy" does not appear in the LiveBoard window.
[0233] When the Play command is invoked, both the LiveBoard window
and timeline interface are updated synchronously. After a while the
word "redundancy" will appear on the LiveBoard.
[0234] Temporal to Spatial Indexing
[0235] Now the user notices that there were some events on the
timeline just before the event on the selection track. he user
selects the visual indicators representing these events on the
timeline, and immediately the corresponding elements of the drawing
are highlighted in the LiveBoard window. That is, the correlation
between the drawing and the timeline is bi-directional.
[0236] This is illustrated in FIG. 18. The visual indicator 1804
are selected from the timeline interface 1803. In the LiveBoard
window 1801, the word "router" 1802 is highlighted (illustrated
here by the dashed circle.) Thus the event corresponding to the
visual indicator 1804 is associated with the word "router".
[0237] Multiple Events Per Graphical Object
[0238] Next, the user sees a bold box on the diagram in the
LiveBoard window and selects the box. Three visual indicators are
displayed on the selection track of the timeline interface
(alternatively, the three visual indicators could have been
highlighted on the Edit track). The first type of visual indicators
designate the creation events for the box, the second type of
visual indicators designate the line-width-changing events when the
box was made bold; and the third type of visual indicators
designate the event of moving the box on the drawing. As noted
above, the visual indicators on the timeline interface are visually
distinct to indicate the kind of events they represent. The user is
interested in why the box is bold and so moves the time marker to
the line-width-changing events and invokes playback using the
playtool.
[0239] This is illustrated in FIG. 19. The box 1902 is highlighted
in LiveBoard window 1901. The visual indicators 1904-1906 are
highlighted in the timeline interface 1903. As described above,
each of these visual indicators represents a particular type of
event associated with the object. Further, in the currently
preferred embodiment, each visual indicator will have some visual
characteristic, typically color, which will correspond to the type
of event.
[0240] The user selects visual indicator 1904 from which to
commence replay.
[0241] Indexing by Location in the Objects Area
[0242] Next, the user considers a diagram on another page of the
drawing. This diagram was drawn, erased, and redrawn several times
throughout the meeting; and the user wants to hear why the earlier
versions were not considered to be correct. The user selects the
area of the drawing where the diagram is located. Now, several
sections of the timeline are highlighted, revealing all the events
for all the objects that were ever in that area of the drawing,
including objects that have been deleted or moved. The user moves
the time marker to the first highlighted deletion visual indicator
to find the discussion of why the first version was changed.
[0243] A visual cue that objects will be or were in a particular
location is ghost objects. Ghost object are faint outlines of
objects used to indicate that at some point in time during the
session, an object was at this particular location. A user may
notice various object ghosts and want to know what was or will be
there (e.g. a list of items where at the end of a session it is
apparent by the ghost object that an item was erased).
[0244] This is illustrated in FIG. 20. Referring to FIG. 20, the
user has selected area 2002 in the diagram of the LiveBoard window
2001. Briefly referring to FIG. 16, the area 2001 corresponds to
the area containing the list of words, "add", "router" and
"redundancy". The timeline interface 2003 has now highlighted
multiple visual indicators 2004-2006 which relate to events that
correspond to events associated with the area 2002, namely events
associated with the words "add", "router" and "redundancy". It
should be noted that this is merely a spatial correlation, namely,
an event representing a word that was erased on the list may also
have been highlighted. Further illustrated in FIG. 20 is "ghost"
object 2007. At this point in the playback, the object at the
location indicated by "ghost" object 2007 has been erased.
[0245] LiveBoard Window as an Editor
[0246] As described above, an editor permits a user to add
timestream and event data after the fact. When the LiveBoard Window
is used as an editor, what is edited is the markings on the
LiveBoard (or new markings added). In this case, additions and or
deletions to the LiveBoard timestream are made as a result of such
editing. Alternatively, a separate timestream may be created.
[0247] The LiveBoard Window when used as an editor provides a very
effective vehicle for enabling a non-participant to efficiently
review the recorded session. This is in part because all the basic
capabilities of the LiveBoard are available during the replay of
the session. This is best described with reference to FIGS. 21 and
22 showing the LiveBoard Window at the end of a session both before
and after an editing session. The LiveBoard in this example is
operating in the bouncing ball playback mode.
[0248] Referring to FIG. 21, various handwritten markings appear on
the LiveBoard window 2101. As discussed above, each of these
handwritten markings may be used to index into the session.
However, during some meetings some of the markings may be
extraneous (e.g. mark 2102), or even illegible (e.g. mark 2103).
Moreover, there may even have been important points that were
discussed, but somehow never made it on to the LiveBoard.
[0249] FIG. 22 illustrates the LiveBoard window of FIG. 21 after
someone has edited it. Referring to FIG. 22, the edited LiveBoard
window 2201 has been expanded to accommodate notations made by the
editor. The edited LiveBoard window 2201 makes use of clocks and
inserted text to provide more indices and information. In FIG. 22,
text has been associated with each clock to indicate what is being
discussed at that point. So for example, the text 2203 can be used
to indicate what the mark 2103 means. The clock/text 2202 indicates
what the collection of markings represent and when creation of the
markings began. Clearly, the edited LiveBoard window would enable a
subsequent viewer to more effectively use the LiveBoard window as a
playback controller.
[0250] As an editor, the existing markings on the LiveBoard window
may be changed. This may done for example to erase the extraneous
marking, e.g. the marking 2102 of FIG. 21 so as to not detract the
subsequent viewer of the window.
[0251] User Control of Captured Timestreams
[0252] Another aspect of the timestream architecture is control of
captured timestreams. Users are very concerned about captured
timestreams, especially timestreams which are "literal" records
like audio and video. They are concerned with who has access to the
literal records of their activities and conversations. They are
concerned with knowing when they are being recorded, and they want
control over this. On the other hand, after an interesting but
unrecorded discussion, users often wish that they had recorded
it.
[0253] User control is supported in the timestream architecture.
However, implementation requires user interface tools to
effectively give control to the user, both during the capture of
sessions as well as afterwards.
[0254] The timestream architecture provides for special treatment
of "Control Events". A Control Event specifies
[0255] a time span (start time and duration),
[0256] which timestreams to control,
[0257] what kind of control (purge level of protection), and
[0258] when the control takes effect.
[0259] Given that captured sessions can have multiple timestreams,
a Control Event can selectively control them. For example, it may
be useful to control just the audio during a sensitive span of a
discussion. A Control Event can also specify all timestreams in the
session.
[0260] There are several kinds of control. The recorded material
can be physically purged from the database. Access to hearing or
viewing the recorded material can be denied or given to specific
users or groups of users. Access can be of different types, such as
access to be able to read only, to be able to append new material,
to be able to fully edit the material, or to be able to change the
access controls. For example, Control Events may specify that only
the chair of a meeting may edit the meeting records, that only the
manager of the group may change the access controls, that only the
meeting's attendees may append new material to the captured
records, and that only a specific set of other individuals may
listen to the captured audio.
[0261] Finally, the timing of the controls can be specified. This
is most useful for purging. Captured records can be purged at
different times, such as immediately upon specification (e.g., to
eradicate a personnel discussion), right after a session (e.g., to
erase an uninteresting meeting), or days or months later (e.g., for
archiving and storage management). But it may also be specified
that access to a meeting's records be denied to non-attendees for a
week, giving the chair time to edit the records.
[0262] While the Timestream architecture makes it possible for
Control Events to specify a variety of controls, the architecture
does not implement them directly, but delegates control to the
various components of the architecture. Many of the specifications
can be encoded in the database to enforce them. The timestream
Players and the Timeline interface can also help enforce some
access controls. The purging usually must be implemented by
Recorders, or by some process that understands a particular
timestream's data format. A purging process can either overwrite
the data to be purged ("zero it out") or actually rewrite and
compress the records by leaving out the data to be purged. The
Timestream architecture does not per se guarantee a full
implementation of the Control Events, but only to do the best it
can with components available in a given situation.
[0263] It has been determined that providing access controls in a
time-based way is very subtle in general. For example, suppose that
the audio/video record of a certain 10-minute span of discussion is
to be purged because it deals with a sensitive decision; and
suppose that the video record showed a whiteboard on the wall. Even
if the 10-minute span is purged from the video, there is no
guarantee that remnants from that discussion do not remain on the
whiteboard after that span. As a practical matter, however,
time-based controls are useful most of the time.
[0264] Control Events are only useful if users can easily create
and edit them. It is natural for users to specify Control Events
with the Timeline Interface after a session.
[0265] In the currently preferred embodiment, a simple set of user
interface tools are provided to give the users unobtrusive control
of audio recording during the session. It is important to make
users aware of when recording is taking place. The red light on a
video camera does this. For the LiveBoard, a flashing "On Record"
is displayed while recording is taking place. Pause and Record
buttons, both hard buttons on physical devices and soft buttons on
either the LiveBoard or computer display allow the users to turn
the recorders on and off. But this control must be anticipated: the
user must know ahead of time that the coming activity is either
interesting or sensitive and therefore to either Record or Pause
the recorders. In practice, this is not effective: users often do
not recognize these situations until well after they are started.
Thus, post-hoc control is needed.
[0266] Our user interface provides for this by implementing a
concept of "On Record" and "Off Record" (in addition to Pause and
Record), which allows users to control recording after the fact,
but within a session in an appropriate manner. The idea is that a
whole session is actually recorded, users are allowed to mark parts
of the session as being On Record or Off Record, and after the
session the Off Record parts of recordings are purged.
[0267] When a session is started for recording, a flashing "On
Record" notice is displayed, along with an Off Record button. When
the Off Record button is pressed, the user can mark the session to
be off the record as of now or as of N minutes ago. For example, if
a discussion starts shifting to a sensitive topic and the
discussants note this after a few minutes, they can then set the
last, say, 5 minutes to be Off Record. Similarly, when the session
is off the record, a flashing "Off Record" is displayed along with
an On Record button, which allows the user to mark the session as
on the record. For example, when the discussion gets interesting,
the last 10 minutes can be put back on the record. These controls
persist to the end of the session, when the users could decide that
the whole session is to be put on or off the record.
[0268] What these user interface tools do is to cause Control
Events to be created during the session (off record segments are
marked as purged and on record segments marked as allowing access).
After the session is closed, a process is run that analyzes the
produced Control Events for conflicting specifications (i.e., spans
of the session are marked as both on and off the record) and then
calls the Recorders to purge the records. One technique for
conflict resolution is to give precedence to more recent Control
Events. However, a user can ask to see the Control Events via the
Timeline interface and edit them before calling for a purge.
[0269] One difficulty in this user interface is that it is
difficult for a user to know how many minutes back in time to
change the record. One improvement for this would be to use our
audio analysis tools to given the user more meaningful time points.
For example, after pressing the Off Record button, a menu of backup
points to recent audio pauses or speaker changes could be
presented. The user could be allowed to playback from these to
determine the correct time point.
[0270] Thus, a computer controlled display system for accessing
contemporaneously timestreams of information is disclosed. While
the present invention is described with respect to a preferred
embodiment, it would be apparent to one skilled in the art to
practice the present invention with other configurations of
information retrieval systems. Such alternate embodiments would not
cause departure from the spirit and scope of the present
invention.
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