Multiplex communications – Communication techniques for information carried in plural... – Combining or distributing information via frequency channels
Reexamination Certificate
2001-03-27
2003-12-09
Nguyen, Kim (Department: 3713)
Multiplex communications
Communication techniques for information carried in plural...
Combining or distributing information via frequency channels
C348S423100
Reexamination Certificate
active
06661808
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an apparatus for coding and multiplexing multimedia information such as, digitalized video signals, aural signals, and other information, and transmitting the information or accumulating the information therein. Specific examples that the present invention can be applied to include a digital broadcasting system, a video on demand, a community antenna television system, and a video conference system or the like with a transmission path such as a satellite and a ground wave, a coaxial cable, and an optical fiber.
BACKGROUND OF THE INVENTION
FIG. 13
is a block diagram showing a transport stream (described as TS herein after) multiplexing transmission device for multiplexing and transmitting information as a transport stream which is an example of a multiplexed bit stream disclosed in, for instance, “Image and information engineering and broadcasting technology” issued by Institute of Television Engineers of Japan, Vol. 49, No. 4, (Whole Number 560), special number MPEG “3-4 system” (April, 1995 number thereof).
In
FIG. 13
, designated at the reference numeral
1
is a clock generating section, at
2
a video coding section, at
3
an aural coding section, at
4
a information coding section, at
5
a program-specific information generating section, at
6
a media multiplexing section, at
7
a
,
7
b
, . . . ,
7
n
a program generating section respectively, at
8
an all program control information generating section, and at
9
a program multiplexing section.
Next description is made for a method of generating a program-a in the program generating section
7
a
of the TS multiplexing transmission device as operations of an example thereof based on the conventional technology. A video signal
102
, an aural signal
103
, various information signals
104
are coded as an information source in the video coding section
2
, the aural coding section
3
, and the information coding section
4
respectively, so that video coded information
106
, aural coded information
107
, information coded information
108
can be obtained. The inputted coded information is contained in packets which are multiplexed as a bit stream by the media multiplexing section
6
.
Description is made herein for a transport stream packet (described as a TS packet hereinafter) with a fixed length comprising 188 bytes as an example of packetizing.
FIG. 14
shows configuration of a TS packet, in the figure, designated at the reference numeral at
113
is a packet header with a 4-byte length, at
114
a packet ID number (described as a PID number hereinafter), and at
115
packet information with a 184-byte length. The video coded information
106
, aural coded information
107
, and information coded information
108
each coded according to the information source are putted into packet information
115
of the TS packet which has different PID numbers
114
respectively. As an example herein, it is assumed that the video coded information
106
is transmitted with a packet having a PID number of PID-aV, the aural coded information
107
with a packet having a PID number of PID-aA, and the information coded information
108
with a packet having a PID number of PID-aD. On the other hand, the coded information in the packet information
115
is identified as each of media types according to the PID numbers
114
in the packet header
113
in the receiving side.
On the other hand, the clock generating section
1
generates, for instance, as a system clock source, a 27-MHz system clock from a 13.5-MHz clock signal
101
used for sampling of a video signal
102
, and outputs clock information
105
for the generated clock at a specified time interval. The clock information
105
is putted in the TS packet in the media multiplexing section
6
for transmission, and is used for regeneration of the clock in the receiving side. Herein, it is assumed that clock information
105
is transmitted with a packet having a PID number of PD-aC. Detailed description will be made later for a clock regenerating method using this clock information
105
.
In the program-specific control information generating section
5
, program-specific control information
109
shown in
FIG. 15
is generated. In the information, PID numbers of a packet each used for transmitting the video coded information
106
, the aural coded information
107
, the information coded information
108
and the clock information
105
, media types to each of the coded information, and a coding system are described as information for packet ID numbers. This program-specific control information
109
is also designated as a program map table (PMT).
The media multiplexing section
6
generates TS packets having PID numbers corresponding to inputted video coded information
106
, aural coded information
107
, and information coded information
108
respectively, and in addition, by containing the program-specific control information
109
in a TS packet, the media multiplexing section
6
generates a program-specific control information packet with a PID number of PID-aM. In this case, the clock information
105
generated by the clock generating section
1
is included in the packet with a PID number of PID-aC. Finally, the media multiplexing section
6
multiplies all the packets for the generated video/audio/information/program-specific control information, and generates a packet of program information
110
a
for the program-a. Similarly, each of the program generating sections
7
b
to
7
n
generates each program information
110
b
, . . . ,
110
n
for each program.
All program control information
111
as shown in
FIG. 16
is generated by the all program control information generating section
8
. Information for all programs contained in program multiplexed information
112
is written in the all program control information
111
, and, for instance, a number of programs, all titles of the program, a PID number of each of the program-specific control information packets, and view ability restricting information or the like are included therein. PID-aM, PID-bM, . . . , PID-nM as PID numbers of program-specific control information packets for the programs a, b, . . . , n are written in the example shown in FIG.
16
. This all program control information
111
is also called as Program Association Table (PAT).
Then, the program multiplexing section
9
packetizes the all program control information
111
generated by the all program control information generating section
8
to generate an all program control information packet with PID-P (e.g. 0×00) as a prespecified PID number, multiplexes the generated packet with the TS packets for the program information
110
a
,
110
b
, . . . ,
110
n
generated by the program generating sections
7
a
,
7
b
, . . . ,
7
n
, and outputs the multiplexed packets as the program multiplexed information
112
. In a case where a information generating speed for information to be transmitted (in this case, the program information
110
a
,
110
b
, . . . ,
110
n
and all program control information
111
) is slower than an output rate (speed) of the program multiplexed information
112
specified at a speed in the transmission path, a null packet (packet information
115
in a TS packet is dummy information) is inserted into the program multiplexed information to match the processing speed by the program multiplexing section
9
.
Description is made for operations of a TS receiver for receiving the program multiplexed information
112
transmitted from the TS multiplexing transmission device and regenerating the received information in accordance with the flow of a media regenerating processing shown in FIG.
17
.
The TS receiver, when starting to receive program multiplexed information
112
after starting up, at first, fetches thereinto a packet with the prespecified PID number of PID-P, and obtains all program control information.
Then, it is known that programs a, b, . . . , n are contained in the program multiplexed information
112
according to the obtain
Fujita Yuka
Kato Yoshiaki
Murakami Tokumichi
Mitsubishi Denki & Kabushiki Kaisha
Nguyen Kim
LandOfFree
Remultiplexing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Remultiplexing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Remultiplexing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3145089