U.S. patent application number 12/135794 was filed with the patent office on 2008-10-02 for method and system for devices efficiently sharing information regarding the content of a digital television bit-stream.
This patent application is currently assigned to SONY CORPORATION. Invention is credited to Sho Kou.
Application Number | 20080243760 12/135794 |
Document ID | / |
Family ID | 39643398 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080243760 |
Kind Code |
A1 |
Kou; Sho |
October 2, 2008 |
METHOD AND SYSTEM FOR DEVICES EFFICIENTLY SHARING INFORMATION
REGARDING THE CONTENT OF A DIGITAL TELEVISION BIT-STREAM
Abstract
A method and system for efficiently allowing a controller device
to receive information from a tuner device regarding the content of
a digital television bit-stream. The present invention first
receives a digital television bit-stream at a tuner device. The
digital television bit-stream comprises video, audio, and data
information, as well as tables that describe the content of the
bit-stream. Next, to obtain a table, a controller device sets a
value specifying a desired table in an attribute field of a
command. Next, the controller sets at least one flag in a flag
field of the command. The setting of the flag indicates the table
which is being requested. Additionally, because a single attribute
field may hold different types of information, the flags indicate
which type of information is in the attribute field for this
issuance of the command. The controller, then issues the command to
the tuner, which determines what table is being requested, based
upon the flags set. The tuner then returns that table to the
controller.
Inventors: |
Kou; Sho; (Saratoga,
CA) |
Correspondence
Address: |
SONY C/O MURABITO, HAO & BARNES LLP
TWO NORTH MARKET STREET, THIRD FLOOR
SAN JOSE
CA
95113
US
|
Assignee: |
SONY CORPORATION
Tokyo
NJ
SONY ELECTRONICS INC.
Parkridge
|
Family ID: |
39643398 |
Appl. No.: |
12/135794 |
Filed: |
June 9, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09596853 |
Jun 19, 2000 |
7406706 |
|
|
12135794 |
|
|
|
|
60146071 |
Jul 28, 1999 |
|
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Current U.S.
Class: |
1/1 ; 348/E7.063;
707/999.001; 707/E17.001 |
Current CPC
Class: |
H04N 21/2362 20130101;
H04N 21/4104 20130101; H04N 21/43615 20130101; H04N 7/165 20130101;
H04N 21/4345 20130101 |
Class at
Publication: |
707/1 ;
707/E17.001 |
International
Class: |
G06F 17/30 20060101
G06F017/30 |
Claims
1. A method of providing information related to a digital media
bit-stream, said method comprising: accessing a command requesting
data associated with a first table from said digital media
bit-stream, said command comprising: an attribute field associated
with a plurality of attributes, wherein a first attribute of said
plurality of attributes is associated with said first table, and
wherein a second attribute of said plurality of attributes is
associated with a second table; and a flag field operable to assign
said first attribute to said attribute field, said flag field
further operable to associate said first attribute field with said
first table; accessing said data associated with said first table
from said digital media bit-stream, wherein said data comprises
information associated with said first attribute; and communicating
said data to a device issuing said command.
2. The method of claim 1 further comprising: executing said
command; and in response to an execution of said command, accessing
said data associated with said first table from said digital media
bit-stream.
3. The method of claim 1, wherein said first table is associated
with information selected from a group consisting of system
information and event information.
4. The method of claim 1, wherein said first table is selected from
a group consisting of a rating region table, an event information
table, and an extended text table.
5. The method of claim 1, wherein said first table is selected from
a group consisting of a system time table, master guide table,
terrestrial version channel table, and a cable version channel
table.
6. The method of claim 1, wherein said command comprises a direct
select data command.
7. The method of claim 1, wherein said command further comprises a
second attribute field associated with a third attribute and a
fourth attribute, wherein said flag field is further operable to
assign said third attribute to said second attribute field, and
wherein said flag field is further operable to associate said third
attribute field with said first table.
8. The method of claim 1, wherein said first attribute is selected
from a group consisting of a most significant bit, a second most
significant bit, a third most significant bit, and a least
significant bit.
9. A data structure for identifying requested information from a
digital media bit-stream, said data structure comprising: an
attribute field associated with a plurality of attributes, wherein
a first attribute of said plurality of attributes is associated
with said first table, and wherein a second attribute of said
plurality of attributes is associated with a second table; and a
flag field operable to assign said first attribute to said
attribute field, said flag field further operable to associate said
first attribute field with said first table; and wherein said
attribute field and said flag field are for requesting data from
said digital media bit-stream associated with said first table.
10. The data structure of claim 9, wherein said attribute field and
said flag field further comprise executable information for
accessing said data associated with said first table from said
digital media bit-stream.
11. The data structure of claim 9, wherein said first table is
associated with information selected from a group consisting of
system information and event information.
12. The data structure of claim 9, wherein said first table is
selected from a group consisting of a rating region table, an event
information table, and an extended text table.
13. The data structure of claim 9, wherein said first table is
selected from a group consisting of a system time table, master
guide table, terrestrial version channel table, and a cable version
channel table.
14. The data structure of claim 9, wherein said attribute field and
said flag field comprise a direct select data command.
15. The data structure of claim 9 further comprising: a second
attribute field associated with a third attribute and a fourth
attribute; and wherein said flag field is further operable to
assign said third attribute to said second attribute field, and
wherein said flag field is further operable to associate said third
attribute field with said first table.
16. The data structure of claim 9, wherein said first attribute is
selected from a group consisting of a most significant bit, a
second most significant bit, a third most significant bit, and a
least significant bit.
17. A system comprising: a first device operable to access a
digital media bit-stream; a second device coupled to said first
device, said second device for generating a command requesting data
associated with a first table from said digital media bit-stream,
said command comprising: an attribute field associated with a
plurality of attributes, wherein a first attribute of said
plurality of attributes is associated with said first table, and
wherein a second attribute of said plurality of attributes is
associated with a second table; and a flag field operable to assign
said first attribute to said attribute field, said flag field
further operable to associate said first attribute field with said
first table; and wherein said first device, in response to
accessing said command, is operable to access said data associated
with said first table from said digital media bit-stream, wherein
said data comprises information associated with said first
attribute, and wherein said first device is further operable to
communicate said data to said second device.
18. The system of claim 17, wherein said first device comprises a
tuner operable to receive and decode a digital television
signal.
19. The system of claim 17, wherein said second device comprises a
controller for issuing commands to said first device, and wherein
said second device is further operable to process information
received from said first device.
20. The system of claim 17, wherein said first device is further
operable to execute said command, and wherein said first device, in
response to an execution of said command, is further operable to
access said data associated with said first table from said digital
media bit-stream.
21. The system of claim 17, wherein said first table is associated
with information selected from a group consisting of system
information and event information.
22. The system of claim 17, wherein said first table is selected
from a group consisting of a rating region table, an event
information table, an extended text table, a system time table,
master guide table, terrestrial version channel table, and a cable
version channel table.
23. The system of claim 17, wherein said command further comprises
a second attribute field associated with a third attribute and a
fourth attribute, wherein said flag field is further operable to
assign said third attribute to said second attribute field, and
wherein said flag field is further operable to associate said third
attribute field with said first table.
24. The system of claim 17, wherein said first attribute is
selected from a group consisting of a most significant bit, a
second most significant bit, a third most significant bit, and a
least significant bit.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation application of
U.S. patent application Ser. No. 09/596,853, filed Jun. 19, 2000,
naming Sho Kou as the inventor, and having attorney docket number
SONY-50N3456.01, which claims the benefit of U.S. Provisional
Patent Application No. 60/146,071, filed Jul. 28, 1999. These
applications are incorporated herein by reference in their entirety
and for all purposes.
BACKGROUND OF THE INVENTION
[0002] The process of transmitting digital television signals,
whether terrestrially or over cable, involves digitizing,
compressing, and multiplexing video and audio signals into a single
bit-stream before transmitting them. The bandwidth in a typical
terrestrial broadcast is wide enough to transmit a number of
compressed digitized television channels over the same bit-stream.
Additionally, data such as, weather reports, stock prices, news,
pay-per-view information, and classified advertisements may be
multiplexed into the bit-stream.
[0003] Because the bit-stream contains a variety of information,
there must be a way for the receiving end to know the content of
the bit-stream. Therefore, Program and System Information Protocol
(PSIP) tables are multiplexed into the bit-stream to describe both
system information and event information of the signal within the
bit-stream. System information allows navigation and access to each
of the television channels within the bit-stream. Event (or program
guide) information describes content information for browsing and
selection. The Program and System Information Protocol (PSIP)
describes a protocol for transmission of a collection of such data
tables within the bit-stream. (See, e.g., the specification
entitled, "Program and System Information Protocol for Terrestrial
Broadcast and Cable", Advanced Television System Committee,
Document A65, Dec. 23, 1997).
[0004] Some examples of the tables are the System Time Table (STT)
which carries time information needed for an application requiring
synchronization. The Master Guide Table (MGT) lists version
numbers, length in bytes, and Packet Identifiers (PIDs) for all of
the PSIP tables except the System Time Table. The Virtual Channel
Table (VCT) contains a list of attributes for all channels carried
in the bit-stream. This table has a terrestrial version (TVCT) and
a cable version (CVCT). The Rating Region Table (RRT) carries
rating information, e.g., G, PG, R, etc. for various geographic
regions. The Event Information Table (EIT) contains information
regarding events on channels in the bit-stream, such as titles and
start times. The Extended Text Table (ETT) contains detailed
information about channels and events in the bit-stream.
[0005] When one device in a digital television receiving system
needs information about the bit-stream from another device, it
issues a Direct Select Data (DSD) command. This command is part of
the AV/C (Audio Video Control) Tuner Model and Command Set
Specification and allows event and navigational information
provided by the service providers to be understood. The information
includes the tables discussed above.
[0006] In particular, the DSD command has a
dsd_selection_specification[n] field, which is used to specify
which table is to be accessed. FIG. 1 illustrates a
dsd_selection_specification[n] field 200. The byte at offset 00
comprises flags 251. When a flag 251 is set, the value in the
associated attribute field 260, is valid. For example, when the
table_id flag 252 is set, the associated table_id attribute field
262 contains a valid table_id. If the table_id flag 252 is not set,
then whatever value that may be in the table_id attribute field 262
is invalid, but a space is nevertheless reserved for it. The same
applies to the flags 254-258 and their respective associated
attribute fields 264-271.
[0007] For the issuing device to request the MGT, TVCT, CVCT, or
STT table, the table_id flag 252 is set and the table_id is
specified in the table_id attribute field 262. Selecting the Rating
Regions table is accomplished by setting the table_id flag 252 and
rating region 256 flag, as well as specifying the table_id 262 and
the rating_region 267. Selecting the Event Information Table is
accomplished by setting the table_id flag 252 and source_id flag
254, as well as specifying the table_id attribute 262 and the
source_id attributes 264-265. Selecting the Extended Text Table is
accomplished by setting the table_id flag 252 and ETM_id flag 258,
as well as specifying the table_id attribute 262 and the ETM_id
attributes 268-271.
[0008] The issuer of the DSD command requests just one table at a
time. Therefore, a separate command 200 must be issued for each
table. Unfortunately, many bytes in the DSD command data structure
are not used. For example, when the issuer requests an event
information table, attribute fields 266-271 are not used at all.
Therefore, the command structure 200 is inefficient, and many of
these command structures are issued during the normal course of
system activity. Consequently, memory space on the devices is
wasted. Additionally, bandwidth is wasted transmitting a command
200 with bytes that have no meaning or use.
SUMMARY OF THE INVENTION
[0009] Therefore, it would be advantageous, then, to provide a
method and system for efficiently allowing a controller device to
receive information from a tuner device regarding the content of a
digital television bit-stream. What is further needed is a method
and system which does not require substantial memory space in the
devices. What is even further needed is a method and system which
takes a minimum of bandwidth to transfer the information between
the devices.
[0010] The present invention provides a method and system for
efficiently allowing a controller device to receive information
from a tuner device regarding the content of a digital television
bit-stream. The present invention does so with an efficient command
structure which does not waste memory space in the devices.
Furthermore, the present invention provides for a method and system
which uses bandwidth efficiently. Further still, the present
invention is compatible with existing standards. The present
invention provides these advantages and others not specifically
mentioned above but described in the sections to follow.
[0011] A method and system for efficiently allowing a controller
device to receive information from a tuner device regarding the
content of a digital television bit-stream is disclosed. The
present invention first receives a digital television bit-stream at
a tuner device. The digital television bit-stream comprises video,
audio, and data information, as well as tables that describe the
content of the bit-stream. Next, to obtain a table, a controller
device sets a value specifying a desired table in an attribute
field of a command. Next, the controller sets at least one flag in
a flag field of the command. The setting of the flag indicates the
table which is being requested. Additionally, because a single
attribute field may hold different types of information, the flags
indicate which type of information is in the attribute field for
this issuance of the command. The controller, then issues the
command to the tuner, which determines what table is being
requested, based upon the flags set. The tuner then returns that
table to the controller. Using the present invention, the command
data structure only reserves space for valid data and does not
require the allocation of data space for invalid data, thereby
making the present invention more efficient over the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention is illustrated by way of example, and
not by way of limitation, in the figures of the accompanying
drawings and in which like reference numerals refer to similar
elements.
[0013] FIG. 1 is an illustration of a Direct Select Data command
which is issued from a controller device to a tuner device to
request information about a bit-stream of digitized television
data, according to conventional techniques.
[0014] FIG. 2 is an illustration of the components used to form a
bit-stream of digitized television information, which is an input
to an embodiment of the present invention.
[0015] FIG. 3 is an illustration of an audio-visual network, in
which an embodiment of the present invention may be practiced.
[0016] FIG. 4 is a schematic of a computer system, which may be
useful to implement an embodiment of the present invention.
[0017] FIG. 5 is an illustration of a compact Direct Select Data
command which is issued from a controller device to a tuner device
to request information about a bit-stream of digitized television
data, according to an embodiment of the present invention.
[0018] FIG. 6 is a flowchart illustrating the steps of a controller
device requesting and receiving information regarding a bit-stream
of television information, according to an embodiment of the
present invention.
[0019] FIG. 7 is a flowchart illustrating the steps of a tuner
device determining the type of information to send to the
controller, according to an embodiment of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In the following detailed description of the present
invention, a system and method for efficiently allowing a
controller device to receive information from a tuner device
regarding the content of a digital television bit-stream, numerous
specific details are set forth in order to provide a thorough
understanding of the present invention. However, it will be
recognized by one skilled in the art that the present invention may
be practiced without these specific details or with equivalents
thereof. In other instances, well known methods, procedures,
components, and circuits have not been described in detail as not
to unnecessarily obscure aspects of the present invention.
Notation and Nomenclature
[0021] Some portions of the detailed descriptions which follow are
presented in terms of procedures, steps, logic blocks, processing,
and other symbolic representations of operations on data bits that
can be performed on computer memory. These descriptions and
representations are the means used by those skilled in the data
processing arts to most effectively convey the substance of their
work to others skilled in the art. A procedure, computer executed
step, logic block, process, etc., is here, and generally, conceived
to be a self-consistent sequence of steps or instructions leading
to a desired result. The steps are those requiring physical
manipulations of physical quantities. Usually, though not
necessarily, these quantities take the form of electrical or
magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated in a computer system. It has
proven convenient at times, principally for reasons of common
usage, to refer to these signals as bits, values, elements,
symbols, characters, terms, numbers, or the like.
[0022] It should be borne in mind, however, that all of these and
similar terms are to be associated with the appropriate physical
quantities and are merely convenient labels applied to these
quantities. Unless specifically stated otherwise as apparent from
the following discussions, it is appreciated that throughout the
present invention, discussions utilizing terms such as "indexing"
or "processing" or "computing" or "translating" or "calculating" or
"determining" or "scrolling" or "displaying" or "recognizing" or
the like, refer to the action and processes of a computer system,
or similar electronic computing device, that manipulates and
transforms data represented as physical (electronic) quantities
within the computer system's registers and memories into other data
similarly represented as physical quantities within the computer
system memories or registers or other such information storage,
transmission or display devices.
EMBODIMENTS OF THE INVENTION
[0023] The present invention provides for a method and system for
efficiently allowing a controller device to send requests to and
receive information from a tuner device regarding the content of a
digital television bit-stream in a network of audio/video
components. The present invention uses the valid flags from a
direct select data (DSD) command structure from the AV/C Tuner
Model and Command Set Specification to not only indicate that an
attribute field of the command is valid, but to also specify what
type of information is being represented in the attribute fields.
In this fashion, a single attribute field may be used to represent
different types of information, depending on how the flags are
configured. This provides for an efficient DSD command structure
because data spaces do not have to be allocated for unused or
invalid data.
[0024] FIG. 2 illustrates a system 150 for producing a bit-stream
160 of multiplexed digital television information. System 150
inputs analog audio and video signals, which are digitized by A/D
converters 170 and 172. Therefore, multiple television channels may
exist in a single bit-stream. Next, the signals are compressed at
compression stages 180 and 182. The compressed signals are input to
multiplexer 188, along with data 185 to produce a single bit-stream
160. Furthermore, tables 190 are multiplexed into the bit-stream
160 to provide information regarding the content of the bit-stream
160 itself. These tables 190 may be PSIP tables containing
information about the content of the bit-stream, although it will
be understood that the present invention is well-suited to operate
with tables 190 in the bit-stream 160 in other formats, as
well.
[0025] FIG. 3 illustrates an audio-visual network 300, in which the
present invention may be practiced, having a number of devices
(302-308) connected by a IEEE 1394 serial bus, which serves as a
communication link. Example devices are television set-top boxes,
camcorders, VCRs, and the like. One of the devices, for example, a
set-top box, acts as a controller 306 and issues commands when the
controller 306 needs event or system information regarding the
bit-stream 160. The target device (e.g., a tuner 308) executes the
command and returns the requested information, for example, a table
190 to the controller 306. The tuner 308 may be any device capable
of receiving the digital bit-stream 160. The present invention is
well-suited to operate with other bus types and device types.
Furthermore, it is not required that a controller device 306 issue
the command and that a tuner device 308 receive the command. For
example, other devices may send and/or receive the command.
[0026] FIG. 4 illustrates circuitry of computer system 100, which
may form a platform upon which to perform an embodiment of the
present invention in one or more of the devices. Namely, any of the
devices in FIG. 3 may include computer system 100. Computer system
100 includes an address/data bus 99 for communicating information,
a central processor 101 coupled with the bus for processing
information and instructions, a volatile memory 102 (e.g., random
access memory RAM) coupled with the bus 99 for storing information
and instructions for the central processor 101 and a non-volatile
memory 103 (e.g., read only memory ROM) coupled with the bus 99 for
storing static information and instructions for the processor 101.
Computer system 100 also includes an optional data storage device
104 coupled with the bus 99 for storing information and
instructions.
[0027] FIG. 5 illustrates a command structure 500 that the
controller device 306 may issue to the tuner device 308 in one
embodiment of the present invention. Command 500 is realized in
computer readable memory and can be broadcast as a digitized
message or "packet" from one device to another. The controller 306
issues this command 500 when information regarding the content of
the bit-stream 160 is needed. The command 500 is comprised of a
flag field 501 comprising the flags: table_id 502, source_id 504,
rating_region 506, and ETM_id (Extended Text Message) 508. In one
embodiment of the invention, flags 504-508 are mutually exclusive.
However, flag 502 may be set with any other flag. The present
invention is suited to using other types of flags or additional
flags in the flag field 501. Also, the order of flags may be
altered, if desired. The settings of these flags defines which
tables 190 the command issuer (e.g., controller 306) wishes the
command receiver (e.g., tuner 308) to send back.
[0028] Command 500 in FIG. 5 also comprises attribute fields 511,
which contain information regarding the type of information which
the issuer of the command 500 seeks. In one embodiment, the type of
information comprises system information such as, the SST, MGT,
TVCT, and CVCT tables, and event information, such as the RRT, EIT,
and ETT tables. In particular, attribute field 521 is the table_id
attribute field. Attribute field 522 may contain three different
types of information. First, the most significant byte (MSB) of the
source_id attribute field, second the MSB of the rating region
attribute field, and third the MSB of the ETM_id attribute field.
By using a single attribute field 522 to represent three different
types of information (one at a time), this embodiment of the
present invention saves memory space in the devices and reduces the
size of the command 500 to be transferred between devices. Also,
the command 500 does not need to reserve data space for invalid
data.
[0029] In a similar fashion, attribute field 523 may comprise three
different types of information. First, the least significant byte
(LSB) of the source_id attribute field, second, the LSB of the
rating region attribute field, and third, the second MSB of the
ETM_id attribute field. Attribute fields 524 and 525 comprise,
respectively, the third MSB and LSB of the ETM_id attribute field.
It will be appreciated that the order of the attribute fields 511
and which attributes are assigned to a given field is not critical
to gaining efficiency. Hence, the present invention is well-suited
to other arrangements of attributes fields 511 in the command
500.
[0030] The issuer of the command 500 selects the desired table as
follows. To select the MGT, the TVCT, the CVCT, or the STT, the
table_id flag 502 is set by the command issuer. Additionally, the
appropriate value is specified in the table_id attribute field 521.
To select the Rating Region Table, the table_id flag 502 is set
along with the rating region flag 506. Additionally, the
appropriate values are set in attribute fields 522 and 523.
[0031] To select the Event Information Table, the table_id flag 502
and the source_id 504 flag are set. Additionally, the appropriate
value is set in attribute fields 522-523. To select the extended
Text Table, the table_id flag 502 and the ETM_id flag 508 are set.
Additionally, the appropriate values are specified in attribute
fields 522-525.
[0032] FIG. 6 illustrates a flowchart of the steps of a process 600
of a controller 306 requesting and receiving information regarding
a bit-stream 160 from tuner 308. At step 610, tuner 308 receives a
bit-stream 160 of digitized television information. This signal
comprises digitized video, digitized audio, as well as data
information. The digitized signal may be in MPEG format, although
the present invention is not limited to signals using this format.
The data information may include data such as weather reports,
stock prices, etc. Additionally, tables which describe the content
of the bit-stream 160 itself may be a part of the bit-stream. One
format for these tables is described in a standard entitled
"Program and System Information Protocol for Terrestrial Broadcast
and Cable," Advanced Television System Committee, Document A65,
Dec. 23, 1997. However, the present invention is well-suited to
operate on bit-streams with tables of other formats.
[0033] In step 620 of this embodiment of the present invention a
controller 306 sets a value in an attribute field 511 in a command
500 for requesting information about the content of the bit-stream
160. The command 500 may be a direct select data (DSD) command,
which is described in the AV/C Tuner Model and Command Set
Specification. The information requested may be a table 190, such
as described herein. Each table 190 has its own attributes to avoid
confusion when selecting the tables 190.
[0034] In step 630, the controller 306 sets flags in the command
flag field 501 to specify which table 190 is desired. These flags
also describe what type of information is being represented in the
attribute field 511. For example, if the rating region flag 506 is
set, then the value in the attribute fields 522-523 represent a
rating region table. In this case, attribute fields 522-523 do not
represent source_id or ETM_id table information. (As these fields
can if other flags are selected.) Thus, an attribute field 511 may
refer to different types of data, depending on the flags 501 which
are set. However, no confusion will exist over the type of
information which is being represented in an attribute field 511
for a given command 500.
[0035] In step 640, the controller 306 issues the command 500 to
the tuner 308. In step 650, the tuner 308 executes the command and
returns the requested table 190 to the controller 306.
[0036] FIG. 7 illustrates a flowchart of a process 700 of the tuner
308 determining what table 190 from the bit-stream 160 to return to
the controller 308. In step 710, the controller 306 issues a
command 500 to the tuner 308. In step 720, the tuner 308 checks to
see if the table_id flag 502 is set. As this embodiment of the
present invention requires this flag to be set for all requests,
the tuner 308 will not return any table 190 if this flag 502 is not
set. If it is set then, at step 730, the tuner 308 checks to see if
the rating region flag 506 is also set. If so, the tuner 308
references, in step 735, the values in attribute fields 522-523.
These values are used to send back rating region table information
to the controller 306. As only one table 190 may be returned per
command 500, the process then goes to the end step.
[0037] If the rating region table flag 506 was not set, then at
step 740, the tuner 308 checks the source_ID flag 504. If it is
set, then the very same attribute fields (522 and 523) used in step
735 for rating region attributes are now used, in step 745 for
event table attributes. The tuner references these attribute fields
522-523 and returns an event table 190 to the controller 306. This
concludes command processing as only one table 190 may be returned
per command 500.
[0038] If the source_ID flag 504 was not set, then the tuner 308
checks for the ETM_id flag 508. If it is set, then the tuner 308
references attribute fields 522-525. Using that information, the
tuner 308 returns an ETM table 190 to the controller 306. Because
the ETM attribute field overlaps with other attribute fields in the
command structure, the command is compact and hence efficient.
Again, the process ends here after the table 190 is returned to the
controller 306.
[0039] If the ETM_id flag 508 was not set, then the tuner 308
refers to the table id attribute field 521 to determine whether
tables 190, such as MGT, TVCT, CVCT, or STT are to be returned. It
will be borne in mind that the order of checking the flags 501 is
not critical and that other flags 501 and attribute fields 511 may
also be used.
[0040] The preferred embodiment of the present invention a method
and system for efficiently allowing a controller device to receive
information from a tuner device regarding the content of a digital
television bit-stream, is thus described. While the present
invention has been described in particular embodiments, it should
be appreciated that the present invention should not be construed
as limited by such embodiments, but rather construed according to
the below claims.
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