U.S. patent application number 09/729660 was filed with the patent office on 2002-05-30 for method and apparatus for delivering and displaying information for a multi-layer user interface.
Invention is credited to Bayrakeri, Sadik, Comito, John P., Gordon, Donald F..
Application Number | 20020066101 09/729660 |
Document ID | / |
Family ID | 26943234 |
Filed Date | 2002-05-30 |
United States Patent
Application |
20020066101 |
Kind Code |
A1 |
Gordon, Donald F. ; et
al. |
May 30, 2002 |
Method and apparatus for delivering and displaying information for
a multi-layer user interface
Abstract
Techniques for transmitting multiple "slices" of information for
a particular location of a user interface, which can be used to
present more information to a viewer for a limited-size viewing
area. Multiple slices can be associated with a particular slice
location of a user interface. In a first slice delivery and
presentation scheme, multiple slices for a particular location of
an interactive program guide (IPG) page are transmitted from the
head-end at different times, and the slices can be appropriately
time stamped for presentation at the designated times. In a second
scheme, multiple slices are concurrently transmitted for a
particular location of an IPG page, and one of the multiple slices
can be selected for processing and display. In a third scheme, one
slice is transmitted for each slice location, and additional slices
can be transmitted for a particular location upon receiving a
request from the terminal.
Inventors: |
Gordon, Donald F.; (Los
Altos, CA) ; Bayrakeri, Sadik; (Foster City, CA)
; Comito, John P.; (Redwood City, CA) |
Correspondence
Address: |
Truong T. Dinh
DINH & ASSOCIATES
2506 Ash Street
Palo Alto
CA
94306
US
|
Family ID: |
26943234 |
Appl. No.: |
09/729660 |
Filed: |
December 4, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60253417 |
Nov 27, 2000 |
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Current U.S.
Class: |
725/43 ;
348/E5.103; 348/E5.104; 348/E5.105; 348/E5.108; 348/E5.112;
375/240.01 |
Current CPC
Class: |
H04N 21/426 20130101;
H04N 21/44222 20130101; H04N 21/43074 20200801; H04N 21/4316
20130101; H04N 21/845 20130101; H04N 21/25883 20130101; H04N 21/482
20130101; H04N 21/4821 20130101; H04N 21/6581 20130101; H04N
21/42204 20130101; H04N 21/4314 20130101; H04N 21/234 20130101;
H04N 21/47 20130101; H04N 5/45 20130101; H04N 21/25891 20130101;
H04N 21/262 20130101 |
Class at
Publication: |
725/43 ;
375/240.01 |
International
Class: |
H04N 005/445 |
Claims
What is claimed is:
1. A method for providing information for a user interface having
included therein a plurality of regions, the method comprising:
defining a plurality of slice locations for a guide region of the
user interface, wherein each slice location corresponds to a
respective area and location in the guide region; associating a
plurality of guide slices for each of at least one slice location
in the guide region; encoding one or more guide slices for each
slice location in the guide region; and transmitting one or more
encoded guide slices for each slice location in the guide
region.
2. The method of claim 1, further comprising: associating one guide
slice for each slice location in the guide region not associated
with a plurality of guide slices.
3. The method of claim 1, wherein a plurality of sets of guide
slices are transmitted for the plurality of slice locations in the
guide region.
4. The method of claim 3, wherein the plurality of sets of guide
slices are transmitted via time division multiplexing.
5. The method of claim 3, wherein one set of guide slices is
transmitted for each group of pictures (GOP).
6. The method of claim 3, further comprising: time-stamping each
set of guide slices for presentation at a designated time.
7. The method of claim 3, wherein at least one set of guide slices
comprises a partial set of guide slices in the guide region.
8. The method of claim 3, wherein the plurality of sets of guide
slices are transmitted with a common packet identifier (PID).
9. The method of claim 3, wherein each of the plurality of sets of
guide slices is transmitted with a respective packet identifier
(PID).
10. The method of claim 1, wherein the transmitting includes p1
continually transmitting a first set of guide slices for the
plurality of slice locations in the guide region.
11. The method of claim 10, wherein the transmitting further
includes transmitting one or more additional guide slices at a
designated time
12. The method of claim 11, wherein the one or more additional
guide slices are transmitted in response to a received request for
the additional guide slices.
13. The method of claim 1, wherein the guide slices transmitted for
the guide region are intra-coded.
14. The method of claim 1, wherein each transmitted guide slice
includes a header indicative of a start location and a stop
location for the guide slice.
15. The method of claim 1, wherein each transmitted guide slice
includes a guide listing for a particular channel in the user
interface.
16. A method for providing information for a user interface,
comprising: defining a plurality of slice locations for at least a
portion of the user interface, wherein each slice location
corresponds to a respective area and location in the user
interface; associating a plurality of slices for each of at least
one slice location in the user interface; encoding one or more
slices for each slice location in the user interface; and
transmitting one or more encoded slices for each slice location in
the user interface.
17. The method of claim 16, wherein the one or more encoded slices
for each slice location includes guide data for an interactive
program guide.
18. A method for providing a user interface having included therein
a plurality of regions, the method comprising: receiving a
bitstream comprising packets for a plurality of slices for a guide
region of the user interface, wherein each slice is designated for
presentation at a particular slice location in the guide region,
and wherein multiple slices are transmitted for each of at least
one slice location in the guide region; retrieving from the
bitstream packets for a set of slices for the guide region; and
decoding the retrieved packets to form the guide region of the user
interface.
19. The method of claim 18, wherein a plurality of sets of slices
are received for the guide region, the method further comprising:
decoding packets for the plurality of sets of slices; and
presenting the plurality of sets of slices in the guide region at
times designated by the a header associated with the slices.
20. The method of claim 18, wherein the plurality of sets of slices
are presented in the user interface via time division
multiplexing.
21. The method of claim 18, further comprising: receiving a user
selection for a particular slice location of the guide region;
retrieving from the bitstream packets for an additional slice
associated with the selected slice location; and decoding the
retrieved packets for the additional slice to form an updated user
interface having included therein the additional slice.
22. The method of claim 18, wherein each slice includes a header
indicative of a start location and a stop location for the
slice.
23. The method of claim 22, wherein the header for each slice is a
slice start code defined by MPEG-2 standard.
24. The method of claim 22, wherein each decoded slice is presented
at a location identified by the header.
25. The method of claim 22, further comprising: modifying a
particular property of each of one or more decoded slices for
presentation at locations on the user interface different from
locations identified by headers of the decoded slices.
26. The method of claim 18, further comprising: recombining the
slices for the guide region with slices for at least one additional
region in the user interface.
27. The method of claim 26, wherein the recombining is performed in
accordance with a splicing syntax defined by MPEG-2 standard.
28. A method for providing a user interface, comprising: receiving
a bitstream comprising packets for a plurality of slices for the
user interface, wherein each slice is designated for presentation
at a particular slice location in the user interface, and wherein
multiple slices are transmitted for each of at least one slice
location in the user interface; retrieving from the bitstream
packets for a set of slices for the user interface; and decoding
the retrieved packets to form the user interface having included
therein the set of slices.
29. The method of claim 28, wherein the one or more encoded slices
for each slice location includes guide data for an interactive
program guide.
30. A terminal configured to provide a user interface having
includes therein a plurality of regions, comprising: a demodulator
operative to receive and demodulate a modulated signal to provide a
transport stream; a transport de-multiplexer coupled to the
demodulator and operative to receive and process the transport
stream to provide a sequence of packets for a plurality of slices
for a guide region of the user interface, wherein each slice is
designated for presentation at a particular slice location in the
guide region, and wherein multiple slices are transmitted for each
of at least one slice location in the guide region; and at least
one video decoder coupled to the transport de-multiplexer and
operative to receive and decode the sequence of packets to form the
guide region of the user interface.
31. The terminal of claim 30, further comprising: a controller
operative to receive a user selection for a particular slice
location in the guide region and to direct the transport
de-multiplexer to retrieve, from the transport stream, packets for
an additional slice associated with the selected slice location,
and wherein the at least one video decoder is further operative to
decode the retrieved packets for the additional slice to form an
updated user interface having included therein the additional
slice.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional
application Ser. No. (Attorney Docket No. 19880-003800), entitled
"METHOD AND APPARATUS FOR INTERACTIVE PROGRAM GUIDE AND ADVERTISING
SYSTEM," filed Nov. 27, 2000, which is incorporated herein by
reference in its entirety for all purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to communication systems in
general. More specifically, the invention relates to techniques to
efficiently deliver interactive program guide (IPG) and other
multimedia information in a server-centric system.
[0003] Over the past few years, the television industry has seen a
transformation in a variety of techniques by which programming is
distributed to consumers. Cable television systems are doubling or
even tripling system bandwidth with the migration to hybrid fiber
coax (HFC) cable plant. Direct broadcast satellite (DBS) systems
have also emerged as a viable alternative to customers unwilling to
subscribe to local cable systems. A variety of other approaches
have also been attempted, which focus primarily on high bandwidth
digital technologies, intelligent two-way set top terminals, or
other methods to try to offer service differentiated from standard
cable and over-the-air broadcast systems.
[0004] With this increase in bandwidth, the number of programming
choices has also increased. Leveraging off the availability of more
intelligent set top terminals (STTs), several companies have
developed elaborate systems for providing an interactive listing of
a vast array of channel offerings, expanded textual information
about individual programs, and the ability to look forward as much
as several weeks in advance to plan television viewing.
[0005] Unfortunately, the existing program guides have several
drawbacks. First, these guides tend to require a significant amount
of memory at the set top terminal. Second, the terminals may be
very slow to acquire the current database of programming
information when they are turned on for the first time or are
subsequently restarted (e.g., a large database may be downloaded to
a terminal using only a vertical blanking interval (VBI) data
insertion technique). Such slow database acquisition may
disadvantageously result in out of date information or, in the case
of services such as pay-per-view (PPV) or video-on-demand (VOD),
limited scheduling flexibility for the information provider. Third,
the user interface of existing program guides do not usually look
like a typical television control interface; rather the user
interface looks like a 1980's style computer display (i.e., having
blocky, ill-formed text and/or graphics).
[0006] Therefore, efficient and effective techniques to deliver
interactive program guide and other multimedia information to a
large number of viewers, and which that ameliorate the
above-described problems, are highly desirable.
SUMMARY OF THE INVENTION
[0007] The present invention provides techniques for transmitting
multiple "slices" of information for a particular location of a
user interface. These techniques can be used to present more
information to a viewer on a limited-size viewing area, and are
well suited for interactive program guide (IPG) commonly used for
television and broadcast distribution systems. The techniques
described herein may also be advantageously used for other
applications and other guides such as, for example, dining guide,
local shopping, news, and others.
[0008] In accordance with an aspect of the invention, multiple
slices can be associated with a particular slice location of the
IPG page. These multiple slices can be used to present more
information (i.e., content) at the slice location. Various schemes
can be used to deliver and present the multiple slices in an
intelligible manner while reducing the amount of clutter.
[0009] In a first slice delivery and presentation scheme, multiple
slices for a particular location of an IPG page are transmitted
from the head-end at different times. For example, the multiple
slices can be transmitted at different GOP times, and the slices
can be appropriately time stamped for presentation at the desired
GOP times. In a second scheme, multiple slices are concurrently
transmitted for a particular location of an IPG page. In this
scheme, a terminal can receive the transmitted slices, select one
of the multiple slices for processing, and process and display the
selected slice. In a third scheme, one slice is transmitted for
each slice location, and additional slices can be transmitted for a
particular location by the head-end upon receiving a request from
the terminal.
[0010] An embodiment of the invention provides a method for
delivering information for a user interface that includes a number
of regions. In accordance with the method, which is generally
performed at a head-end of an information distribution system, a
number of slice locations for a first (e.g., guide) region of the
user interface are defined, with each slice location corresponding
to a respective area and location in the guide region. A number of
(e.g., guide) slices are associated with each of at least one slice
location in the guide region. One or more guide slices are encoded
for each slice location in the guide region and transmitted.
[0011] A number of sets of guide slices can be transmitted for the
slice locations in the guide region, for example, in a time
division multiplexed manner in which one set of guide slices is
transmitted for each group of pictures (GOP). Alternatively, one
set of guide slices may be continually transmitted and additional
sets may be transmitted as requested. The transmitted slices can be
time-stamped for presentation at the designated times.
[0012] Another embodiment of the invention provides a method for
presenting a user interface that includes a number of regions. In
accordance with the method, which is generally performed at a
terminal, a bitstream comprising packets for a number of slices for
a first (e.g., guide) region of the user interface is received.
Each slice is designated for presentation at a particular slice
location of the guide region, and multiple slices are transmitted
for each of at least one slice location of the guide region.
Packets for a set of slices for the guide region are retrieved from
the bitstream and decoded to form the guide region of the user
interface.
[0013] A number of sets of slices may be received for the guide
region. In this case, the sets of slices may be decoded and
presented at times designated by a header associated with the
slices. The sets of slices can be presented in a time division
multiplexed manner, or upon receiving a directive to update the
slices in the guide region.
[0014] The invention further provides other methods and system
elements (i.e., terminal and server) that implement various
aspects, embodiments, and features of the invention, as described
in further detail below.
[0015] The foregoing, together with other aspects of this
invention, will become more apparent when referring to the
following specification, claims, and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The teachings of the invention can be readily understood by
considering the following detailed description in conjunction with
the accompanying drawings.
[0017] FIG. 1 is a block diagram of an embodiment of an information
distribution system that can be used to provide interactive program
guide (IPG) and is capable of implementing various aspects of the
invention;
[0018] FIG. 2A is a diagram of a specific design of an IPG page
used to present a program listing and other information to
viewers;
[0019] FIGS. 2B and 2C are diagrams of an embodiment of a
background video and a guide video, respectively, for the IPG page
shown in FIG. 2A;
[0020] FIGS. 3A through 3C are diagrams of data structures (i.e.,
matrices) of program guide data for a group of IPG pages, and which
may be used in conjunction with picture-based encoding, slice-based
encoding, and temporal slice persistence encoding,
respectively;
[0021] FIG. 3D is a diagram that shows an implementation of
demand-cast with the use of temporal slice persistence
technique;
[0022] FIG. 4 is a diagram of a specific design of a channel
information window (i.e., a spotlight window) that can also be used
to efficiently provide IPG information;
[0023] FIG. 5 is a block diagram of an embodiment of terminal
capable of providing a display of a user interface and implementing
various aspects of the invention;
[0024] FIG. 6 is a diagram of a specific design of an IPG page that
can be used to illustrate various aspects and embodiments of
multiple slices transmission; and
[0025] FIGS. 7A through 7C are diagrams that illustrate various
slice delivery and presentation schemes whereby multiple slices are
transmitted for a particular location of an IPG page.
[0026] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common within a figure.
DESCRIPTION OF THE SPECIFIC EMBODIMENTS
[0027] A. System
[0028] FIG. 1 is a block diagram of an embodiment of an information
distribution system 100 that can be used to provide interactive
program guide (IPG) and is capable of implementing various aspects
of the invention. Distribution system 100 includes a head-end 102,
(optional) local neighborhood equipment (LNE) 104, one or more
distribution nodes 106 (e.g., a hybrid fiber-coax network), and a
number of terminals 108 (e.g., set top terminals). Each LNE 104 may
serve one or more distribution nodes 106, and each distribution
node 106 is typically associated with a respective neighborhood
that includes a number of terminals 108.
[0029] Head-end 102 produces a number of digital streams that
contain encoded information in (e.g., MPEG-2) compressed format.
These digital streams are then modulated using a modulation
technique that is compatible with a communication channel 162 that
couples head-end 102 to LNE 104 and/or distribution node 106. LNE
104 is typically located away from head-end 102. LNE 104 selects
data for viewers in the LNE's neighborhood and re-modulates the
selected data into a form suitable for transmission to the
associated distribution node(s) 106. Although system 100 is
depicted as having head-end 102 and LNE 104 as separate elements,
the functions of LNE 104 may be incorporated into head-end 102.
Also, the elements of system 100 can be physically located
anywhere, and need not be near each other.
[0030] In distribution system 100, program streams may be
continually transmitted from the head-end to the terminals (i.e.,
broadcast) or may be addressed to particular terminals that
requested the information via an interactive menu (referred to
herein as "demand-cast"). An interactive menu structure suitable
for requesting video-on-demand (VOD) is disclosed in commonly
assigned U.S. patent application Ser. No. 09/533,006, entitled
"METHOD AND APPARATUS FOR PROVIDING A MENU STRUCTURE FOR AN
INTERACTIVE INFORMATION DISTRIBUTION SYSTEM," and incorporated
herein by reference. Another example of an interactive menu
suitable for requesting multimedia services is an interactive
program guide disclosed in commonly assigned U.S. patent
application Ser. No. 09/293,526, entitled "DATA STRUCTURE AND
METHODS FOR PROVIDING AN INTERACTIVE PROGRAM GUIDE," filed Apr. 15,
1999, and incorporated herein by reference.
[0031] To assist a viewer to select programming, head-end 102
produces information that can be assembled to create an "IPG page"
such as that shown in FIG. 2A. Head-end 102 produces the components
of the IPG page as bitstreams that are compressed prior to
transmission. Terminals 108 thereafter receive and demodulate the
transmission from head-end 102 and decode the compressed bitsteams
to retrieve the IPG pages.
[0032] Within distribution system 100, a video source 112 supplies
one or more video sequences for a video portion of the IPG pages
(also referred to herein as "barker" videos), an audio source 114
supplies one or more audio signals associated with the video
sequences, and a guide data source 116 provides program guide data
for a guide portion of the IPG pages. The guide data is typically
stored and provided in a particular (e.g., text) format, with each
guide entry describing a particular program by its title,
presentation time, presentation date, descriptive information,
channel, and program source. The video sequences, audio signals,
and program guide data are provided to an encoder unit 120 within
head-end 102.
[0033] Encoder unit 120 (which is described in further detail
below) compresses the received video sequences into one or more
elementary streams, the audio signals into one or more elementary
streams, and the guide videos produced from the guide data into one
or more elementary streams. The elementary streams can be produced
using a number of encoding techniques such as, for example,
"picture-based" encoding, "slice-based" encoding, "temporal slice
persistence" (TSP) encoding, "strobecast", as well as other types
of encoding, or a combination thereof.
[0034] Picture-based encoding is described in detail in U.S. patent
application Ser. No. 09/384,394, entitled "METHOD AND APPARATUS FOR
COMPRESSING VIDEO SEQUENCES," filed Aug. 27, 1999. Slice-based
encoding is described in detail in U.S. patent application Ser. No.
09/428,066, entitled "METHOD AND APPARATUS FOR TRANSMITTING VIDEO
AND GRAPHICS IN COMPRESSED FORM," filed Oct. 27, 1999. Temporal
slice persistence encoding is described in detail in U.S. patent
application Ser. No. (Attorney Docket No. 19880-003410), entitled
"TEMPORAL SLICE PERSISTENCE METHOD AND APPARATUS FOR DELIVERY OF
INTERACTIVE PROGRAM GUIDE," filed Oct. 10, 2000. Strobecast
encoding and delivery is described in detail in U.S. patent
application Ser. No. 09/687,662, entitled "EFFICIENT DELIVERY OF
INTERACTIVE PROGRAM GUIDE USING DEMAND-CAST," filed Oct. 12, 2000.
These applications are assigned to the assignee of the invention
and incorporated herein by reference.
[0035] In the specific embodiment shown in FIG. 1, encoder unit 120
includes a guide data grid generator 122, a compositor unit 124,
video encoders 126a and 126b, and an audio encoder 128. Additional
video and/or audio encoders may also be included within encoder
unit 120, depending on the particular head-end design. Guide data
grid generator 122 receives and formats the guide data into a
"guide grid", e.g., guide grid region 212 in FIG. 2A.
[0036] Compositor unit 124 receives and combines the guide grid
from grid generator 122 and a video sequence from video source 112,
and may further insert advertising video, advertiser or service
provider logos, still graphics, animation, other information, or a
combination thereof. In an embodiment, compositor unit 124 provides
a background video (e.g., as shown in FIG. 2B) to a first video
encoder 126a and a guide video (e.g., as shown in FIG. 2C) to a
second video encoder 126b. For picture-based encoding, compositor
unit 124 provides a composed video (e.g., as shown in FIG. 2A) to
one video encoder. A number of encoders can be used to encode in
parallel a number of composed videos for a number of IPG pages,
with each IPG page including different guide content.
[0037] In an embodiment, video encoder 126a is a real-time (e.g.,
MPEG-2) encoder that encodes the background video using a
particular encoding technique, and provides one or more (e.g.,
MPEG-2 compliant) bitstreams for the background portion of the IPG
page. In an embodiment, video encoder 126b is a (e.g.,
software-based) encoder that encodes the guide video using a
particular encoding technique, and provides one or more bitstreams
that collectively represent all or a portion of the guide grid.
Each video encoder 126 is designed to efficiently and effectively
encode the respective input video, and may be operated in
accordance with slice-based, picture-based, temporal slice
persistence, or some other encoding technique. Audio encoder 128
(e.g., an AC-3 encoder) receives and encodes the audio signals to
form a bitstream for the audio signals. The video and audio
encoders provide a number of elementary streams containing (e.g.,
picture-based or slice-based) encoded video and audio
information.
[0038] For some applications such as picture-in-picture (PIP) or
picture-in-application (PIA), compositor unit 124 may receive a
number of video sequences and form a composed video having included
therein the video sequences in scaled form (i.e., reduced in size).
For example, nine video sequences may be compressed and arranged
into a 3.times.3 grid. Video encoder 126a then receives and (e.g.,
slice-based) encodes the composed video and produces a number of
elementary streams, one stream for each video sequence. Each video
sequence can thereafter be individually transmitted from the
head-end and flexibly recombined with other (e.g., guide) data
and/or video at the terminal (e.g., to implement PIP or PIA). PIP
and PIA are described in further detail in U.S. patent application
Ser. No. 09/635,508, entitled "METHOD AND APPARATUS FOR
TRANSITIONING BETWEEN INTERACTIVE PROGRAM GUIDE (IPG) PAGES," filed
Aug. 9, 2000, assigned to the assignee of the invention and
incorporated herein by reference.
[0039] A controller 130 couples to encoder unit 120 and manages the
overall encoding process such that the video encoding process is
temporally and spatially synchronized with the grid encoding
process. For slice-based encoding, this synchronization can be
achieved by defining the slice start and stop (macroblock)
locations for each slice and managing the encoding process based on
the defined slices. Slices may be defined, for example, according
to the objects in the IPG page layout.
[0040] The encoding process generates a group of pictures (GOP)
structure having "intra-coded" (I) pictures and "predicted" (P and
B) pictures. For slice-based encoding, the I pictures include
intra-coded slices and the P and B pictures include
predictive-coded slices. In an embodiment, the intra-coded slices
are separated from the predictive-coded slices and transmitted from
the head-end via separate packet identifiers (PIDs). Although not
shown in FIG. 1, the coded slices may be stored in a storage unit.
The individual slices can thereafter be retrieved from the storage
unit as required for transmission from the head-end.
[0041] A transport stream generator (TSG) 140 receives and
assembles the elementary streams from the video and audio encoders
into one or more transport streams. Transport stream generator 140
further manages each transport stream and communicates with a
session manager 150 to form and/or tear down transport streams. In
an embodiment, each transport stream is an MPEG-compliant transport
stream. In this case, transport stream generator 140 may send
program tables to terminals 108 in a private section of the MPEG
transport stream. Such table may include a list of available
streams along with the address of the source transport stream
generator and other information to identify the particular
transport stream to which the table belongs.
[0042] Session manager 150 manages the delivery of IPG pages to
terminals 108 located on one or more distribution nodes 106. In an
embodiment, each distribution node 106 is served by a respective
set of one or more transport streams generated by a transport
stream generator assigned to that node. The transport streams for
each distribution node include broadcast streams (e.g., for IPG
pages continually sent from the head-end) and demand-cast streams
(e.g., for IPG pages sent from the head-end in response to requests
from the terminals). For some implementations, session manager 150
may monitor the demand-cast streams and usage by terminals 108 and
direct the appropriate transport stream generator to generate or
tear down demand-cast streams.
[0043] An in-band delivery system 160 (e.g., a cable modem)
receives and modulates the transport streams from transport stream
generator 140 using a modulation format suitable for transmission
over communication channel 162, which may be, for example, a fiber
optic channel that carries high-speed data from the head-end to a
number of LNE and/or distribution nodes. Each LNE selects the
programming (e.g., the IPG page components) that is applicable to
its neighborhood and re-modulates the selected data into a format
suitable for transmission over the associated distribution
node(s).
[0044] Although not shown in FIG. 1 for simplicity, LNE 104 may
include a cable modem, a slice combiner, a multiplexer, and a
modulator. The cable modem demodulates a signal received from the
head-end and extracts the coded video, guide, data, and audio
information from the received signal. The coded information is
typically included in one or more transport streams. The slice
combiner may recombine the received video slices with the guide
slices in an order such that a decoder at the terminals can easily
decode the IPG without further slice re-organization. The
multiplexer assigns PIDs for the resultant combined slices and
forms one or more (e.g., MPEG-compliant) transport streams. The
modulator then transmits the transport stream(s) to the
distribution node(s).
[0045] LNE 104 can be programmed to extract specific information
from the signal transmitted by the head-end. As such, the LNE can
extract video and guide slices that are targeted to the viewers
served by the LNE. For example, the LNE can extract specific
channels for representation in the guide grid that can be made
available to the viewers served by that LNE. In such case,
unavailable channels to a particular neighborhood would not be
depicted in a viewer's IPG. The IPG may also include targeted
advertising, e-commerce, program notes, and others. To support such
features, each LNE may recombine different guide slices with
different video slices to produce IPG pages that are prepared
specifically for the viewers served by that particular LNE. Other
LNEs may select different IPG component information that is
relevant for their associated viewers. A detailed description of
LNE 104 is described in the aforementioned U.S. patent application
Ser. No. 09/635,508.
[0046] For a server-centric distribution system, the program guide
resides at the head-end and a two-way communication system, via a
back channel 164, is utilized to support communication with the
terminals for delivery of the program guide. Back-channel 164 can
be used by the terminals to send requests and other messages to the
head-end, and may also be used by the head-end to send messages and
certain types of data to the terminals. An out-of-band delivery
system 170 facilitates the exchange of data over the back channel
and forwards terminal requests to session manager 150.
[0047] Other elements within head-end 102 may also interface with
out-of-band delivery system 170 to send information to terminal 108
via the out-of-band network. Fort example, a spotlight server that
produces a spotlight user interface (described below) may interface
with out-of-band delivery system 170 directly to send spotlight
data to terminals 108. Off the shelf equipment including network
controllers, modulators, and demodulators such as those provided by
General Instrument Corporation can be used to implement out-of-band
delivery system 170.
[0048] Distribution system 100 is described in further detail in
the aforementioned U.S. patent application Ser. Nos. 09/687,662 and
(Attorney Docket No. 19880-003410). One specific implementation of
head-end 102 is known as the DIVA.TM. System provided by DIVA
Systems Corporation.
[0049] B. Interactive Program Guide
[0050] A unique way of providing programming schedule and listing
to viewers is a server-centric approach. In this approach, the
complete program guide information spanning a particular time
period (e.g., two weeks of programming) is generated at a head-end
and sent to the terminals in a display-ready compressed video
format.
[0051] FIG. 2A is a diagram of a specific design of an IPG page 200
used to present a program listing and other information to viewers.
In this design, IPG page 200 includes a guide region 210, a video
region 220, an icon region 240, a program description region 250, a
logo region 260, and a time-of-day region 270. Other designs for
the IPG page with different layouts, configurations, and
combinations and arrangements of regions and objects can be
contemplated and are within the scope of the invention. In an
embodiment, guide region 210 includes a guide grid region 212 and a
time slot region 218. Time slot region 218 includes a first time
slot object 218a and a second time slot object 218b that indicate
the (e.g., half-hour) time slots for which program guide is being
provided on the IPG page. Guide grid region 212 is used to display
program listing for a group of channels. In the design shown in
FIG. 2A, the program listing shows the available programming in two
half-hour time slots. Guide grid region 212 includes a number of
channel objects 214a through 214j used to display program
information for the group of channels. A pair of channel indicators
216a and 216b within guide grid region 212 identifies the current
cursor location.
[0052] Program description region 250 is used to present
descriptive information relating to a particular program selected
from the program listing, or may be used to present other
information. Video region 220 may be used to display images,
videos, text, or a combination thereof, which may be used for
advertisements, previews, or other purposes. In the design shown in
FIG. 2A, video region 220 displays a barker video. Logo region 260
may include a logo of a service operator or other entity, and may
be optionally displayed. Time-of-day region 270 may be configured
by the user and may also be optionally displayed.
[0053] Icon region 240 is used to display various icons. Each icon
can represent a filter or a link to either another IPG page or a
particular interface. Each filter selects a particular type of
programming to be included in the program listing shown in guide
region 210. For example, a "Pay Per View" (PPV) icon 241 may be a
filter that selects only PPV programming to be included in the
program listing. A "Favorites" icon 242 may be a filter that
selects only channels designated by the viewer to be among his or
her favorites. A "Movies" icon 243 may be a filter that selects
only movies or movie channels. A "Kids" icon 244 may be a filter
that selects only channels for children or programming appropriate
or produced for viewing by children. A "Sports" icon 245 may be a
filter that selects only sports channels or sports-related
programming. A "Music" icon 246 may be a link to a music interface.
And an "Options" icon 247 may be a link to a menu of IPG options
that the viewer may select amongst. Such options may include (1)
configuration and selection/deselection information of IPG related
services, (2) custom information for deactivating some of the
filters or accessing a custom condensed listing menus, and (3)
other features and functionality.
[0054] FIG. 2B is a diagram of an embodiment of a background video
280 for IPG page 200. In this embodiment, background video 280
includes video region 220, icon region 240, program description
region 250, and logo region 260. As noted above, background video
280 can be efficiently (slice-based) encoded by a video encoder. In
other designs, background video 280 may include additional and/or
different regions than that shown in FIG. 2B.
[0055] FIG. 2C is a diagram of an embodiment of a guide video 290
for IPG page 200. In this embodiment, guide video 290 includes
guide region 210, which includes guide grid region 212 and time
slot region 218. Guide video 290 can also be efficiently
(slice-based) encoded by a video encoder. In other designs, guide
video 290 may include additional and/or different regions than that
shown in FIG. 2C.
[0056] As shown in FIG. 2C, two program titles are provided for
each channel object 214 in guide grid region 212, with each title
corresponding to a respective half-hour time slot. In an
embodiment, a "mask or reveal" feature can be used to display
(i.e., reveal) a desired program title and hide (i.e., mask) the
other program title. For example, channel 12 includes the program
titles "Hemingway" and "Dragon Tails". If the 9:00-9:30 time slot
is selected (as shown in FIG. 2A), the program title "Hemingway"
can be revealed and the other program title "Dragon Tails" can be
masked from view. And if the 9:30-10:00 time slot is selected, the
program title "Hemingway" can be masked and the other program title
"Dragon Tails" can be revealed. The underlying video frame to be
encoded can thus include various objects and items, some of which
may be shown and others of which may be hidden. This mask or reveal
technique can be used for any region of the IPG page.
[0057] The mask or reveal feature and the user interaction
processing are described in the aforementioned U.S. patent
application Ser. Nos. 09/293,526 and 09/533,006.
[0058] A program guide for a large number of channels for a long
time period can be very extensive. For example, 480 IPG pages would
be needed to provide program guide for two weeks of programming for
200 channels, if each IPG page includes a program listing for 10
channels in two half-hour time slots as shown in FIG. 2A. A large
amount of system resources (e.g., bandwidth) would be needed to
continually transmit the complete program guide.
[0059] In an embodiment, to conserve system resources, only a
limited number of IPG pages are continually sent (broadcast) by the
head-end, and remaining IPG pages may be sent as requested by
viewers. The specific number of IPG pages to be broadcasted and
their selection are dependent on the particular system
implementation, and may be defined by a time depth and a program
depth for the program guide. The time depth refers to the amount of
time programming for a particular channel group is provided by the
broadcast video PIDs. And the channel depth refers to the number of
channels available through the program guide (in comparison to the
total number of channels available in the system).
[0060] In an embodiment, a number of video PIDs can be used to send
the program guide for the current and (possibly) near look-ahead
time slots, one or more audio PIDs can be used to send an audio
barker, and (optionally) one or more data PIDs (or other data
transport method) can be used to send the program description data,
overlay data, and/or other data. The elementary streams carrying
the IPG are sent in one or more transport streams.
[0061] For the portion of the program guide that is broadcasted by
the head-end, a viewer is able to quickly retrieve and display IPG
pages formed from the broadcast streams whenever desired.
[0062] If the viewer desires a program listing or other contents
that is not provided by the broadcast streams, then a demand-cast
session may be initiated, for example, as described in the
aforementioned U.S. patent application Ser. No. 09/635,508 and
(Attorney Docket No. 19880-003410). For this demand-cast session,
the terminal sends a message to the head-end, via the back channel,
requesting the desired contents. The head-end processes the
request, retrieves the desired contents from an appropriate source,
generates a video stream for the desired contents and assigns it
with another video PID (and related audio and data PIDs, if any),
and incorporates the video stream into a transport stream.
Preferably, the desired video stream is inserted into the transport
stream currently being tuned/selected by the requesting terminal or
sent in another transport stream. The head-end further informs the
terminal which PID should be received and from which transport
stream the demand-cast video stream should be demultiplexed. The
terminal then retrieves the desired video PID from the transport
stream.
[0063] C. Data Structures and Encoding Techniques
[0064] FIG. 3A is a diagram of a data structure 300 (i.e., a
matrix) of program guide data for a group of IPG pages, and which
may be used in conjunction with picture-based encoding. In this
representation, the horizontal axis represents the video sequences
for different IPG pages to be transmitted, and the vertical axis
represents time indices for the video sequences. In this specific
example, ten video sequences are generated and labeled as IPG pages
1 through 10. Each video sequence is composed of a time sequence of
pictures. In this specific example, each group of 15 pictures for
each video sequence forms a group of pictures (GOP) for that video
sequence. Matrix 300 is illustratively shown to include ten GOPs
for ten IPG pages, but can be designed to have any defined
M.times.N dimension.
[0065] As shown in FIG. 3A, matrix 300 is a two-dimensional array
of elements, with each element representing a picture (or frame).
For simplicity, each element in matrix 300 is illustratively shown
to include a guide portion and a video portion on the left and
right halves of the picture, respectively. The element in the first
column of the first row represents the guide portion (g.sub.1) and
video portion (v.sub.1) of IPG page 1 at time index t.sub.1, the
element in the second column of the first row represents the guide
portion (g.sub.2) and video portion (v.sub.1) of IPG page 2 at time
index t.sub.1, and so on. In the specific example shown FIG. 3A,
the guide portion for each IPG page is different (i.e., g.sub.1,
g.sub.2, . . . , g.sub.10) but the video portion (e.g., v.sub.1) is
common for all ten IPG pages.
[0066] Each of the ten video sequences in matrix 300 can be coded
as a GOP. For example, the video sequence for IPG page 1 can be
coded as a GOP comprised of the coded picture sequence: I1, B1, B1,
P1, B1, B1, P1, B1, B1, P1, B1, B1, P1, B1,and B1, where I
represents an intra-coded picture, P represents a uni-directionally
predictive-coded picture, and B represents a bi-directionally
predictive-coded picture.
[0067] In the example shown in FIG. 3A, matrix 300 includes a group
of intra-coded pictures 312 and a group of predictive-coded
pictures 314 that can be used to fully represent the ten IPG pages.
In an embodiment, intra-coded picture group 312 includes ten
intra-coded pictures at time index t.sub.1 for the ten IPG pages.
These intra-coded pictures can be assigned to PIDs 1 through 10,
which may also be referred to as I-PIDs 1 through 10 to denote that
these PIDs include intra-coded pictures. In an embodiment,
predictive-coded picture group 314 includes 14 predictive-coded
pictures of one of the IPG pages for time indices t.sub.2 through
t.sub.15. Predictive-coded picture group 314 is also assigned a
PID, and may also be referred to as the base-PID or PRED-PID to
denote that this PID includes predictive-coded pictures. The
base-PID may comprise the following picture sequence: B1, B1, P1,
B1, B1, P1, B1, B1, P1, B1, B1, P1, B1, and B1.
[0068] For each IPG page, between time t.sub.1 to t.sub.15, the
guide portion does not change and only the video portion changes.
In each column, the 14 prediction error frames contain zero data
for the guide portion and video prediction error for the video
portion. Therefore, the content of the base-PID is the same for
each IPG page and may be sent only once per group of EPG pages in
the matrix for each GOP period.
[0069] If a viewer wants to view the guide data for a particular
group of channels (i.e., a particular IPG page), a demultiplexer at
the terminal selects the I-PID for the selected IPG page and
recombines the selected I-PID with the base-PID to produce a
recombined stream, which is then decoded by the video decoder.
Picture-level recombination is described in further detail in the
aforementioned U.S. patent application Ser. No. (Attorney Docket
No. 19880-003410).
[0070] FIG. 3B depicts an embodiment of a data structure 320 that
may be used in conjunction with slice-based encoding. In this
example, ten IPG pages are available, with each page represented by
a respective guide portion (g) and a common video portion (v). For
example, IPG page 1 is represented as (g.sub.1/v.sub.1), IPG page 2
is represented as (g.sub.2/v.sub.1), and so on. In data structure
320, ten guide portions g.sub.1 through g.sub.10 are associated
with the video portion (v.sub.1). Slice-based encoding is described
in the aforementioned U.S. patent application Ser. Nos. (Attorney
Docket No. 19880-003410) and 09/635,508.
[0071] As shown in FIG. 3B, the coded slices for the guide and
video portions of the IPG pages can be assigned to a number of
PIDs. In FIG. 3B, only the content that is assigned a PID is
delivered to the terminals. The intra-coded guide portions g.sub.1
through g.sub.10 are assigned to PID 1 through PID 10,
respectively. One of the common intra-coded video portion v.sub.1
(e.g., for IPG page 10) is assigned to PID 11. In this form,
substantial bandwidth saving is achieved by delivering the
intra-coded video portion v.sub.1 only once. Finally, the
predictive-coded pictures g.sub.1/v.sub.2 through g.sub.1/v.sub.15
are assigned to PID 12. Again, a substantial saving in bandwidth is
achieved by transmitting only one group of fourteen
predictive-coded pictures, g.sub.1/v.sub.2 through
g.sub.1/vI.sub.15. The PID assignment and decoding processes are
described in the aforementioned U.S. patent application Ser. No.
(Attorney Docket No. 19880-003410).
[0072] FIG. 3C is a diagram of a data structure 340 that can be
used in conjunction with temporal slice persistence encoding. Data
structure 340 is a matrix representation for program guide data for
a number of IPG pages based on the partitioning of the IPG page
shown in FIGS. 2B and 2C. As shown by the shaded portions in FIG.
3C, a video sequence is formed which contains only the video
portion of the IPG page (i.e., the portion containing time-varying
information). In an embodiment, the coded video sequence contains
only slices that belong to the video region. The coded video
sequence is assigned a particular PID (e.g., V-PID) and transmitted
from the head-end.
[0073] For each IPG page, the guide portion (i.e., the portion
containing the information specific to that IPG page) is sent in a
separate picture frame. Since the guide portion does not change
over time, only one picture for each GOP is coded and transmitted.
The coded guide frame contains only the slices that belong to the
guide portion of a frame. The slice-coded guide portion for each
IPG page is assigned a respective PID (e.g., G-PID) and also
transmitted from the head-end.
[0074] The presentation times of the guide frames and motion video
frames are assigned in accordance with a "temporal slice
persistence" fact. In an embodiment (not represented in FIG. 3C),
the guide PIDs (i.e., G-PID 1, G-PID 2, and so on) are time stamped
to be presented at the end of each GOP at t=15. At t=15, the last
motion video frame in the GOP is dropped and the viewer-selected
guide page is presented. To achieve this, the video decoder
re-combines the selected guide G-PID (e.g., G-PID 1) and the video
V-PID via one of the picture-based recombination methods described
in the aforementioned U.S. patent application Ser. No. (Attorney
Docket No. 19880-003410).
[0075] The selected guide page is decoded and displayed at t=15,
with only the region that contains the guide portion slices being
updated on the screen. From that time on, the guide portion of the
screen is not updated (i.e., the guide slices temporally persist on
the screen) until the viewer selects another guide page. This
selection then updates the slices in the guide portion and rewrites
the new guide portion on the screen. Similarly, the V-PID frames
only change the video portion of the screen and do not update the
guide portion, since these motion video frames do not include
slices in the guide portion.
[0076] The embodiments disclosed with respect to FIG. 3C can be
used for broadcast of IPG pages and can further be used for a
demand-cast of IPG pages in response to viewer requests. For
demand-cast, the head-end can time stamp the requested page to be
processed and quickly displayed on the screen in a suitable time
index within a GOP to reduce delays. The guide frames and motion
video frames can be encoded, delivered, decoded, and displayed in
various manners, as described in the aforementioned U.S. patent
application Ser. No. (Attorney Docket No. 19880-003410).
[0077] In another embodiment that is supported by FIG. 3C, the
V-PID is encoded to include P and B pictures (e.g., a GOP of
I-B-B-P-B-B-P-B-B-P-B-B-P-B-B), and any B picture in the V-PID can
be dropped and replaced with a B-coded guide frame that includes
"intra-coded" macroblocks. This can be achieved by adjusting the
encoding threshold selection that decides whether a macroblock is
better to be encoded as intra-coded or as predictive-coded. Any
B-coded frame can be dropped and replaced since it is not used as a
reference for prediction by any other pictures in a GOP. The guide
page frames can be time stamped to be presented, for example, at
t=2. Other embodiments for encoding and decoding the guide frames
are described in the aforementioned U.S. patent application Ser.
No. (Attorney Docket No. 19880-003410).
[0078] FIG. 3D is a diagram that shows an implementation of
demand-cast with the use of temporal slice persistence technique.
In the example shown in FIG. 3D, a viewer request is received and
processed by the head-end, and the requested guide PID is time
stamped to be displayed at t=3. In this example, the V-PID is coded
to include B frames (e.g., I-B-B-P-B-B-P . . . ), and the B frame
at t=3 is dropped and replaced with a B-coded requested guide PID
that includes intra-coded macroblocks. The B frame of the V-PID can
be dropped at anytime in a GOP since it is not used as a reference
for prediction by any other frame in the GOP.
[0079] The temporal slice persistence technique can be
advantageously employed in a broadcast scenario whereby a large
number of guide PIDs (in the order of hundreds) can be efficiently
delivered. Since the guide PIDs do not carry full motion barker
video, huge bandwidth savings can be achieved. The barker video can
be sent as a separate video stream (e.g., V-PID or another PID).
The temporal slice persistence technique can also be used to
implement other combinations of coding and decoding of guide
frames, full motion video frames, and (possibly) other multimedia
information in a GOP. The temporal slice persistence technique
employs picture-based recombination techniques with slice-based
sub-picture updating mechanisms, as described in the aforementioned
U.S. patent application Ser. No. (Attorney Docket No.
19880-003410).
[0080] By exploiting known characteristics of the IPG pages and the
temporal slice persistence technique, the transmission of redundant
information can be minimized, for example, by employing efficient
client-server communication and acknowledgement techniques. For
example, the guide portion of a requested IPG page may be sent a
limited number of times (e.g., once) in response to a viewer
request for the page. This "strobecast" of IPG pages can greatly
reduce the load for demand-cast, and may (possibly) be used for the
delivery of other contents from the head-end. Strobecast techniques
are described in detail in the aforementioned U.S. patent
application Ser. No. 09/687,662.
[0081] D. Spotlight Window
[0082] FIG. 4 is a diagram of a specific design of a channel
information window 400 (also referred to as a "spotlight window")
that can also be used to efficiently provide IPG information. The
spotlight window can be generated and overlay on top of a video
display (e.g., whenever selected by a viewer). In this design,
spotlight window 400 includes a specific portion 410, a local
portion 420, and a common portion 430. Specific portion 410
includes information specific to a particular broadcast channel
being described by spotlight window 400. Local portion 420 includes
information targeted for delivery to the terminals within a
particular locality. And common portion 430 includes features that
are common for a number of spotlight windows (i.e., the background
that is common for all broadcast channels and localities). FIG. 4
shows a specific design, and additional and/or different
information, layouts, configurations, and arrangements may also be
provided for each portion of spotlight window 400.
[0083] In the design shown in FIG. 4, specific portion 410 includes
the channel number (e.g., "13"), the broadcast channel name (e.g.,
"USA"), the program title (e.g., "Tremors II: . . . "), the time
period of the program (e.g., "9:00-11:00"), the program rating
(e.g., "PG"), the copyright or release year (e.g., "1998"), and a
brief description (e.g., "The creature from . . . ").
[0084] Local portion 420 includes, for example, a logo for the
service provider or other branding related information. A different
logo may be provided for each region served by a different service
provider. Local portion 420 may also be partitioned into a number
of smaller sub-portions, with each sub-portion being used to
provide different information (e.g., targeted advertisements,
locality specific announcements) and may further be associated with
a particular localization level (e.g., an entire region, a
neighborhood, or a set of terminals).
[0085] Common portion 430 includes a filter icon region 440 and an
operational icon region 450. Filter icon region 440 includes a
number of filter icons used to filter the programs to be displayed
in the program guide, e.g., an "All" filter icon, a "Fav" or
favorites filter icon, a "Movies" filter icon, a "Kids" filter
icon, and a "Sports" filter icon. These filter icons can be
designed to provide filtering functionality. Operational icon
region 450 includes a close caption icon ("CC"), a secondary audio
programming icon ("SAP"), and a stereo icon ("Z,900 ").
[0086] In an embodiment, all or portions of the spotlight window
are generated at the head-end and sent to the terminals. In this
manner, the head-end has control over the particular arrangement
(i.e., the layout and configuration) for the spotlight window and
the information to be included in the various fields and portions
of the spotlight window. Bitmap for all or portions the spotlight
window may be encoded at the head-end, packetized, and sent to the
terminals (e.g., via an out-of-band network). The spotlight data
can be processed by a separate spotlight server that does not
interfere with the operations of the session manager or the
transport stream processor to send the spotlight data via the
out-of-band network.
[0087] Techniques for generating, encoding, and delivering
spotlight window is described in U.S. patent application Ser. No.
09/691,495, entitled "SYSTEM AND METHOD FOR LOCALIZED CHANNEL
INFORMATION WINDOW," filed Oct. 18, 2000, assigned to the assignee
of the invention and incorporated herein by reference.
[0088] E. Terminal
[0089] FIG. 5 is a block diagram of an embodiment of terminal 108,
which is also referred to as a set top terminal (STT) or user
terminal. Terminal 108 is capable of producing a display of a user
interface and implementing various aspects of the invention.
Terminal 108 includes a tuner 512, a demodulator 514, a transport
demultiplexer (DEMUX) 518, an audio decoder 520, a video decoder
530, an on-screen display (OSD) processor 532, a video compositor
534, a frame store memory 536, a controller 550, and a modulator
570. User interaction is supported via a remote control unit 580.
Tuner 512 receives a radio frequency (RF) signal comprising, for
example, a number of quadrature amplitude modulated (QAM) signals
from a downstream (forward) channel. In response to a control
signal TUNE, tuner 512 tunes to and processes a particular QAM
signal to provide an intermediate frequency (IF) signal.
Demodulator 514 receives and demodulates the IF signal to provide
an information stream (e.g., an MPEG transport stream) that is sent
to transport stream demultiplexer 518.
[0090] Transport stream demultiplexer 518, in response to a control
signal TD produced by controller 550, demultiplexes (i.e.,
extracts) an audio stream A and a video stream V. The audio stream
A is provided to audio decoder 520, which decodes the audio stream
and provides a decoded audio stream to an audio processor (not
shown) for subsequent processing and presentation. The video stream
V is provided to video decoder 530, which decodes the compressed
video stream V and provides an uncompressed video stream VD to
video compositor 534. OSD processor 532, in response to a control
signal OSD produced by controller 550, produces a graphical overlay
signal VOSD that is provided to video compositor 534.
[0091] Video compositor 534 merges the graphical overlay signal
VOSD and the uncompressed video stream VD to produce a composed
video stream (i.e., the underlying video images with the graphical
overlay). Frame store unit 536 receives and stores the composed
video stream on a frame-by-frame basis according to the frame rate
of the video stream. Frame store unit 536 thereafter provides the
stored video frames to a video processor (not shown) for subsequent
processing and presentation on a display device. In an embodiment,
during transitions between streams for a user interface, the
buffers in the terminal are not reset, and the user interface
seamlessly transitions from one screen to another.
[0092] Controller 550 includes an input/output (I/O) module 552, a
processor 554, support circuitry 556, an infrared receiver (I/R)
558, and a memory 560. Input/output module 552 provides an
interface between controller 550 and tuner 512, demodulator 514
(for some designs), transport demultiplexer 518, OSD processor 532,
frame store unit 536, modulator 570, and a remote control unit 580
via infrared receiver 558.
[0093] Processor 554 interfaces with I/O module 552, support
circuitry 556 (which may include power supplies, clock circuits,
cache memory, and the like), and a memory 560. Processor 554 also
coordinates the execution of software routines stored in memory 560
to implement the features and perform the functions supported by
the terminal.
[0094] Memory 560 stores software routines that support various
functions and features, and further stores data that may be used
for the user interface. In the embodiment shown in FIG. 5, memory
560 includes a user interaction routine 562, a PID mapping table
564, an overlay storage 566, and a stream processing routine 568.
User interaction routine 562 processes user interactions to perform
various functions to provide the desired user interface menu. For
example, user interaction routine 562 can implement a mask or
reveal feature to display (reveal) the desired portion of the IPG
page and hide (mask) the undesired portion. User interaction
routine 562 may further perform various functions to achieve a
demand-cast for a desired IPG page. The mask or reveal is described
in U.S. patent application Ser. Nos. 09/293,526 and 09/533,006.
[0095] Stream processing routine 568 coordinates the recombination
of video streams to form the desired video sequences. Stream
processing routine 3468 employs a variety of methods to recombine
slice-based streams, some of which are described in the
aforementioned U.S. patent application Ser. No. (Attorney Docket
No. 19880-003410). In one recombination method, a PID filter 516
within demodulator 514 is utilized to filter the undesired PIDs and
retrieve the desired PIDs from the transport stream. The packets to
be extracted and decoded to form a particular IPG page are
identified by PID mapping table 564. For most recombination
methods, after stream processing routine 568 has processed the
streams into the proper order, the slices are sent to video decoder
530 (e.g., an MPEG-2 decoder) to form uncompressed IPG pages
suitable for display.
[0096] Although controller 550 is depicted as a general-purpose
processor that may be programmed to perform specific control
functions to implement various aspects of the invention, the
controller may also be implemented in hardware as an application
specific integrated circuit (ASIC).
[0097] In a specific design, remote control unit 580 includes an
8-position joystick, a numeric pad, a "Select" key, a "Freeze" key,
and a "Return" key. User manipulations of the joystick or keys on
the remote control device are transmitted to controller 550 via an
infrared (IR) link or an RF link. Controller 550 is responsive to
the user manipulations and executes the appropriate portion of user
interaction routine 562 to process the user manipulations.
[0098] FIG. 5 shows a specific design of terminal 108. Other
designs of the terminal can also be implemented to perform the
functions described herein, and these alternative designs are
within the scope of the invention.
[0099] F. Multi-layer User Interface
[0100] An aspect of the invention provides techniques for
transmitting multiple "slices" of information for a particular
location of a video screen. These techniques can be used to provide
more information to a viewer for a given limited-size viewing area,
and are well suited for interactive program guide (IPG) commonly
used for television and broadcast distribution systems. However,
the techniques described herein may also be advantageously used for
other applications and other guides such as, for example, dining
guide, local shopping, news, and others.
[0101] For clarity, many aspects and embodiments of the invention
are described below in the context of an interactive program guide
provided via a number of IPG pages. Referring back to FIG. 2A, an
IPG page can be designed having a number of regions (or portions).
Each region can be used to provide a different type of information.
Each region is typically defined to be of a specific size and shape
and is further placed at a specific location on the IPG page. The
specific size, shape, and location of each region and the
arrangement of the regions on the IPG page are typically selected
based on the desired IPG page design.
[0102] FIG. 6 is a diagram of a specific design of an IPG page 600
that can be used to illustrate various aspects and embodiments of
the invention. As shown in FIG. 6 and described above, the LPG page
can be partitioned into a number of regions including a guide
region 610, a video region 620, a filter icon region 640, and a
program description region 650.
[0103] As described in the aforementioned U.S. patent application
Ser. No. (Attorney Docket No. 19880-003410), various techniques can
be used to reduce the amount of data to be transmitted from the
head-end to the terminals for the IPG page. For example, a video
stream for video region 620 can be continually transmitted from the
head-end to the terminals, guide data for guide region 610 can be
transmitted continually (e.g., once for each GOP) or a limited
number of times, and the data in program description region 650 can
be transmitted via a data stream.
[0104] To efficiently encode and transmit the regions of the IPG
page, each transmitted region can be defined with a set of slices.
As shown in FIG. 6, guide region 610 can be defined with a set of M
guide slices and video region 620 can be defined with a set of N
video slices. Other regions may also be defined with their
respective sets of slices, and arbitrary slice shapes can be
defined for any region. Note that in MPEG-2, a slice cannot be
defined exceeding a macroblock row and this is within the scope of
the invention. Slice-based encoding, temporal slice persistence
encoding, or strobecast encoding method can then be applied to
encode and transmit the content from the head-end.
[0105] For the IPG page design shown in FIG. 2A, the guide listing
214 for each channel, which is also referred to as a channel
element, can be defined as a guide slice. Each guide slice is
associated with a specific location in the guide region of the page
and typically includes a slice start code that identifies the start
and the end of the slice. The M guide slices for the M channel
elements of the guide region can be encoded (e.g., a priori) at the
head-end, stored in a storage unit, and transmitted to the terminal
as needed. By processing the slice start code, a decoder at the
terminal is able to determine where to place the decoded slice on
the IPG page, which can be used in any of slice-based, temporal
slice-persistence, and strobecast encoding methods.
[0106] In accordance with an aspect of the invention, multiple
slices can be associated with a particular location of the IPG
page. These multiple slices can be used to present more information
(i.e., content) in a given spatial area of the IPG page.
[0107] Multiple slices can be defined for each channel element of
the guide region to provide additional information about program
titles or selectively different information. In one embodiment,
each channel element may first be associated with a respective
slice that provides the guide data for the channel (e.g., the
channel number, channel short name, and program title, as shown in
FIG. 2A). Each channel element may further be associated with
another slice that provides, for example, a short description of
the program that may be initiated, e.g., upon the viewer selecting
a related object.
[0108] Multiple slices may be interchangeably provided for the
channel listings to provide a slow-moving listing. This same
"slice-looping" behavior may be applied to banners or other objects
in other regions of the user interface (e.g., to catch the
attention of the viewer). In general, for each slice location,
multiple slices of information can be encoded to provide
alternative or additional information.
[0109] Various techniques can be used to present the multiple
slices in an intelligible manner while reducing the amount of
clutter. The presentation of the additional slices can also be in
different manner, such as looping and text extension depending on
the desired user interface functionality.
[0110] 1. Delivery and Presentation Schemes
[0111] The delivery and presentation of the multiple slices for a
particular location of the IPG page can be achieved based on
numerous schemes, some of which are described below.
[0112] FIG. 7A is a diagram that illustrates a first slice delivery
and presentation scheme whereby multiple slices for a particular
location of an IPG page are transmitted from the head-end at
different times. In the example shown in FIG. 7A, a video sequence
containing only slices that belong to the video region of the IPG
page (i.e., the portion containing time-varying information) is
coded, assigned a particular PID, and transmitted from the
head-end. The guide portion (i.e., the portion containing the
information specific to that IPG page) is coded as a set of slices,
assigned another PID, and also transmitted from the head-end.
[0113] Each of the multiple slices can be used to provide different
information to the terminals. The multiple slices can be
transmitted at different GOP times, and the slices can be
appropriately time stamped for presentation at the desired GOP
times. In the example shown in FIG. 7A, two different slices are
alternately provided for a particular channel element of the IPG
page (i.e., a particular slice location) at different GOP times.
For the first guide slice location, a first slice (e.g., slice 1 in
set A) can be time stamped for presentation at a first GOP time, a
second slice (e.g., slice 1 in set B) can be time stamped for
presentation at the next GOP time, the first slice (e.g., slice 1
in set A) can be time stamped for presentation at the following GOP
time, and so on. Any number of slice sets (e.g., A, B, C, and so
on) can be time division multiplexed (TDM) and this is within the
scope of the invention. Moreover, the TDM can be achieved based on
any particular transmission pattern, and needs not be a regular
repeating pattern. For example, the second slice may be transmitted
for every P times the first slice is transmitted.
[0114] In an embodiment, each transmission (e.g., at each GOP) for
a particular IPG page may include a complete set of guide slices
for the guide region of the IPG page (e.g., guide slices 1 through
M, for slice locations 1 through M, respectively). Alternatively, a
transmission may include a partial set of guide slices for the
guide region (e.g., just the guide slices that are new for the
GOP). For guide slices transmitted once per GOP, these slices can
be intra-coded in the manner described above in the aforementioned
U.S. patent application Ser. No. (Attorney Docket No.
19880-003410).
[0115] In an embodiment, the terminal processes the received guide
slices and can continually update the IPG page as new slices are
received for the page. As described above, since the guide data is
typically static over time, one set of intra-coded slices for the
guide data can be transmitted by the head-end for each GOP. In this
case, the processing at the terminal for the guide region can be
achieved on a GOP-by-GOP basis. For each GOP, the terminal
recombines the guide slices with other slices for the IPG page
(e.g., the video slices), decodes the recombined slices, and
displays the decoded slices. If a particular guide slice is not
transmitted for the current GOP, the terminal can skip the
non-transmitted slice and not update the slice previously decoded
for this location, as described in the aforementioned U.S. patent
application Ser. No. (Attorney Docket No. 19880-003410). By
presenting multiple slices for a particular location in a time
division multiplexed manner, more content can be displayed within a
particular spatial region.
[0116] The guide slices can be encoded, time stamped, transmitted,
and decoded in the manner described in the aforementioned U.S.
patent application Ser. No. (Attorney Docket No. 19880-003410).
Encoding and decoding techniques for guide slices transmitted a
limited number of times (e.g., once) is described in the
aforementioned U.S. patent application Ser. No. (Attorney Docket
No. 19880-003410).
[0117] FIG. 7B is a diagram that illustrates a second slice
delivery and presentation scheme whereby multiple slices are
concurrently transmitted for a particular location of an IPG page.
For this scheme, the terminal can receive the transmitted slices,
select one of the multiple slices for processing, and process and
display the selected slice.
[0118] The guide slice to be displayed at a particular location on
the IPG page may be selected, for example, based on user
interaction. In an embodiment, the slices for the channel elements
of the guide listing (e.g., slice set A) can be initially processed
and displayed. The viewer can thereafter highlight a particular
channel element, for example, by clicking on the channel element.
In response to the user selection, the terminal can retrieve,
process, and display another slice (e.g., slice 1 in set B) for the
highlighted channel element. The particular slice selected for
decoding and display may be based, for example, on the particular
key selected by the viewer. In an embodiment, only the highlighted
channel element may be updated in response to the user interaction,
and the other channel elements in the guide region need not be
updated.
[0119] The multiple slices for the particular location may be
transmitted in the same GOP time (as shown in FIG. 7B) or may be
transmitted at different GOP times. Although two slice sets are
illustratively shown in FIG. 7B, any number of slice sets may be
transmitted for the guide region of the IPG page. Furthermore, the
transmission at any particular GOP time may include a full or
partial set of slices for the guide region.
[0120] FIG. 7C is a diagram that illustrates a third slice delivery
and presentation scheme whereby one slice is transmitted for a
particular location, and additional slices can be transmitted by
the head-end upon receiving a request from the terminal. This third
scheme is similar to the second scheme described above, except that
the additional slices are not transmitted from the head-end until
requested by the terminal. This scheme utilizes less bandwidth for
the broadcast slices than the second scheme, but requires (e.g.,
out-of-band or in-band) signaling to send requests for slices.
[0121] At the terminal, the transmitted (e.g., broadcast) slices
are initially received, processed, and displayed. Upon receiving an
indication to display a different slice for a particular location
of the IPG page, the terminal can send a request for the selected
slice to the head-end. The head-end processes the request and sends
the requested slice back to the terminal, which then processes and
presents the slice. The requested slice can be transmitted a
limited number of times (e.g., once) in response to the request, as
described in the aforementioned U.S. patent application Ser. No.
09/687,662.
[0122] In accordance with MPEG-2 standard, each slice typically is
associated with a slice start code that defines the start location
and the stop location for the slice. Typically, the slice is
decoded and presented at a particular location in the screen
identified by the slice start code. In one embodiment, the
transport stream can include multiple of slice start codes for a
particular slice, and the terminal can select one of the slice
start codes for the slice. With this embodiment, the slice can be
placed at the location defined any of the transmitted slice start
codes. In another embodiment, the head-end can defined the slice
start code for a particular slice based on user interaction at the
terminal. In yet another embodiment, the terminal is able to
arrange (i.e., modify) the slice start codes such that the slice
can be placed at any desired location in the screen. Various other
techniques for presenting the slice at a desired location may also
be contemplated and are within the scope of the invention.
[0123] 2. PID Assignment
[0124] For the above-described slice delivery and presentation
schemes, the multiple slices can be assigned to the same or
different PIDs, depending on various factors. In a first
embodiment, the slices for the guide portion for each IPG page can
be assigned to a respective PID. The terminal simply processes the
appropriate PID for the guide portion of the selected IPG page and
displays all slices transmitted with that PID. This embodiment can
be used with the first scheme described above. For example, slices
A and B to be presented at a particular location on the IPG page
but received at different GOP times may be assigned the same
PID.
[0125] In a second embodiment, a set of "primary" slices for the
guide portion for each IPG page can be assigned one PID, and each
set of "secondary" slices for the guide portion for the page can be
assigned another respective PID. The terminal can initially process
and display the primary slices. If a particular primary slice
(e.g., a particular channel element) is highlighted, a second PID
can be processed and the secondary slice for the location
identified for the highlighted primary slice can be retrieved. The
retrieved secondary slice can then be decoded and displayed in
place of the highlighted primary slice. Other primary slices are
not affected and therefore not updated.
[0126] The second embodiment can be used with the second and third
schemes described above. For example, for the second scheme shown
in FIG. 7B, slice set A can be assigned one PID and slice set B can
be assigned another PID. And for the third scheme shown in FIG. 7C,
the broadcast slice set A can be assigned one PID and the
demand-cast slice set B can be assigned another PID.
[0127] For clarity, the use of multiple slices for a particular
location of the IPG page has been specifically described for the
delivery of program guide data for the guide portion of the IPG
page. However, the use of multiple slices can also be applied to
other regions of the IPG page, including the video region, the
filter icon region, and the program description region. Generally,
a primary (or default) set of slices (e.g., slice set A) for a
particular region can be sent to the terminal, which initially
decodes and presents these slices. One or more secondary
(additional) sets of slices (e.g., slice set B) can also be sent
for the region to provide additional information. The secondary
sets of slices may be decoded and presented in a time division
multiplexed manner with the primary set of slices, as shown in FIG.
7A. Alternatively, a particular secondary set of slices (e.g.,
slice set B) may be decoded and presented in response to an event
(e.g., a user interaction).
[0128] In general, depending on the encoding scheme employed (e.g.,
slice-based, termporal slice persistence, strobecast, and so on)
and presentation schedule, different PID assignment schemes can be
utilized and are within the scope of this invention.
[0129] 3. Other Aspects
[0130] As an example of an application using the above-described
aspects of the invention, multiple sets of slices may be sent for
multiple video streams. A primary set of slices may be decoded and
presented for the IPG page. A secondary set of slices may be
decoded and presented, for example, in response to a user selection
of a particular filter icon or a particular channel element. An
audio stream associated with the selected video stream can also be
decoded and presented.
[0131] In an embodiment, each slice transmitted from the head-end
includes a slice start code that identifies the start and stop
locations of the slice. The terminal typically retrieves and
processes the transmitted slice and places the decoded slice at the
specific location identified by the slice start code.
[0132] In an alternative embodiment, the terminal may also elect to
display a received slice at a different location than that
indicated by the slice start code. The presentation of a particular
slice at a different location may be achieved by modifying the
slice start code (or some other property of the slice).
Presentation of a received slice at different locations (e.g., any
location selected by the viewer or terminal) allows the terminal to
flexibly generate multiple views and functionality for the user
interface.
[0133] The viewer or terminal-selected placement of the transmitted
slices may be used, for example, to generate a customized IPG page.
As an example, slices for the guide listing for all channels in the
current time slot may be transmitted. The terminal can generate a
custom IPG page by recombining the slices for the desired channel
elements (in any desired order). The recombined slices can then be
decoded and displayed. The slice start codes may be modified by the
terminal such that the slice for each channel element is recombined
at the appropriate location in the custom IPG page.
[0134] As noted above, the techniques described herein can also be
advantageously used for other applications and other guides. For
example, the techniques described above can be used to deliver
stock quotes, sports scores, headline news, traffic reports, other
guides, and so on, which may be displayed, for example, on a
portion of a screen via the use of multiple slices for each of
these news items. As an example, a first viewer may elect to have
stock quotes continually displayed on the bottom portion of the IPG
page, and a second viewer may elect to have news flashes
continually displayed on the top portion of the IPG page. The news
items can be transmitted via multiple slices, and a particular
slice can be selected by the viewer and displayed at a designated
or viewer-selected location on the IPG page.
[0135] The foregoing description of the preferred embodiments is
provided to enable any person skilled in the art to make or use the
invention. Various modifications to these embodiments will be
readily apparent to those skilled in the art, and the generic
principles defined herein may be applied to other embodiments
without the use of the inventive faculty. Thus, the invention is
not intended to be limited to the embodiments shown herein but is
to be accorded the widest scope consistent with the principles and
novel features disclosed herein.
* * * * *