JP2002280980A - Data broadcast transmitter, receiver, transmission method, and reception method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data broadcast transmitter, receiver, a transmission method and a reception method that can transmit firing of an event message at an NPT(normal play time) used for data broadcast near a discontinuity point, at which a current STC(system time clock) returns to zero. SOLUTION: The data broadcast transmitter 10 has a function of transmitting an event firing signal according to the NPT to receivers, and a control section 18 sets an STC value (STCr) which becomes a reference source in a way that it stays within a range of a past value (STCw1) or a future value (STCw2) by a predetermined value, with respect to a current STC value (STCc) where the NPT is continuous at all times, in the case of transmitting an NPT reference signal. Thus, in the transmission of the NPT reference signal, the problem of being unable to tell to which cycle the STC value belongs in the relation between the STC and the NTP is avoided and proper transmission reception in data broadcast can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data broadcasting in digital broadcasting in which reference time information is transmitted together with MPEG-encoded video data and audio data, and the receiving side uses the reference time information to MPEG-decode video and audio data. The present invention relates to a transmitting device, a receiving device, a transmitting method, and a receiving method.

[0002]

2. Description of the Related Art In digital broadcasting, video data and audio data obtained from an image pickup device are MPEG-encoded on a transmission side, and PCR (Program Clock Reference) which is reference time information together with the encoded data. The receiving side performs MPEG decoding of video data and audio data using the reference time information.

[0003] MPEG (Moving P
Picture Expert Group) has MPEG2. MPE
G2 stands for ISO (International Organization for Stand)
ardization) and IEC (International Electrotechica)
l Commission) Joint Technical Committe (JTC)
This is an encoding standard that has been standardized as ISO / IEC 13818 in e).

[0004] On the other hand, data broadcasting of digital broadcasting differs from conventional data multiplex broadcasting in which data is multiplexed on a television broadcasting signal, in which not only characters and figures but also various expressions such as still images, moving images, and voices are possible. is there. In data broadcasting, various types of information can be extracted and viewed on a screen integrated with a digital broadcast being viewed.

[0005] In data broadcasting in such digital broadcasting, event messages are used. The purpose of operating the event message is to generate an interrupt event in the multimedia content asynchronously or at a specified time, and to simultaneously transmit data accompanying the event, the event message including the general event message descriptor (general event message). Event message), use of NPT (Normal Play Time) as time designation in a general-purpose event message, or NP in multimedia content.
When using T, NPT and STC (System Time Cl
An event message (hereinafter, referred to as an NPT reference message) including an NPT reference descriptor is used to inform a receiver of a relation with a reference synchronization signal (short for ock).

[0006] The purpose of operating the NPT is to specify the time when the content of the data broadcasting service does not need to be corrected even when the program is time-shifted due to an extension of baseball or extraordinary news, or when the CM period is changed during rebroadcasting. This is for use as

[0007] The above-mentioned standards and operating rules for data broadcasting in digital broadcasting are defined by the Association of Radio Industries and Businesses
ation of Radio Industries and Business, hereafter ARI
B), standards and operational rules, AR
IB STD-B24 (data broadcasting encoding and transmission standard in digital broadcasting) and ARIBTR
-It is stipulated in B15 (BS Digital Broadcasting Operation Regulations) and the like.

FIG. 7 shows the count value of an STC counter used in a digital broadcast transmitting / receiving apparatus.
The horizontal axis represents time t, and the vertical axis represents the count value of the STC counter. The case where an upper 33-bit counter is used as the STC counter is shown. STC corresponds to a time count corresponding to real time, and is reset at a period of time T. Accordingly, the STC counter is reset when the count operation is performed for the time T, and the count operation is restarted from there. 2 ^{3-1 on the} vertical axis indicates the STC maximum value to be reset.

FIG. 8 shows the relationship between STC and NPT. As described above, the STC is reset (= 0) at every count value corresponding to the fixed time T, but in FIG. 8, for simplicity, the repetition of each reset of the STC is extended in the horizontal axis direction to form a repetitive waveform. Is represented in In addition, the NPT counter (which is provided on the receiver side) is generally reset for each program or each content, but FIG. 8 shows one program or one program for explaining the conventional problems. The time required for one program or one content without any intervention such as CM or extra news in the content is the maximum value of STC (time T for one round)
It is assumed that it continues beyond

However, conventionally, as shown in FIG.
When there is no intervention such as CM or extra news in a program or one content, and the time required for one program or one content continues beyond the maximum value of the STC (time T to make one round), or the maximum value of the STC Even if a plurality of programs or contents are broadcasted within the program, if a certain program or content is broadcast over a time corresponding to the maximum value of the STC, the STC has the maximum value (time T for one round).
(That is, when the STC is reset), the NPT is also reset at the same time as shown in FIG. 8, even though the program or content has not ended at that time.

Therefore, the NP used in data broadcasting is
Regarding the event time designation by T, the current STC is 0
Since the NPT count is reset at the same time near the discontinuity point returning to the above, even if an event message (time designation such as interruption of the explanation screen) is instructed by the NPT value during reproduction of one program or one content, There was a problem that the event message could not be fired.

[0012]

As described above, the NPT used in the conventional data broadcasting has the current ST.
In the vicinity of the discontinuity point where C returns to zero, there is a problem that a dead zone exists and an event message cannot be fired.

Accordingly, the present invention has been made in view of the above problems, and has been developed for NPT used in data broadcasting.
It is an object of the present invention to provide a data broadcast transmitting device, a receiving device, a transmitting method, and a receiving method that can ignite an event message near a discontinuous point where the signal returns to zero.

[0014]

According to the first aspect of the present invention, an NP
In a data broadcast transmitting apparatus having a means for transmitting an event firing signal based on a T reference signal and an NPT, when transmitting an NPT reference signal, an STC value (STCr) as a reference source is always set to a current STC value (STCc). On the other hand, a predetermined value (S
(TCw) and a means for setting the value to be in the range of the past value (STCw1) or the future value (STCw2).

According to the first aspect of the present invention, in the transmission of the NPT reference signal, the relationship between the STC and the NPT is as follows:
It is possible to solve the problem that the STC time value of which cycle is not known, and it is possible to perform appropriate transmission and reception in data broadcasting.

According to a second aspect of the present invention, the NPT reference signal and the NP
In the data broadcast transmitting apparatus provided with a means for transmitting an event firing signal by T, when transmitting an event firing signal by NPT, a valid firing designation NPT value is always set to a current STC value (STCc). Value in the future (STCw
Means for setting 2) in a range of values converted into NPT.

According to the second aspect of the present invention, it is possible to solve the problem that in the transmission of the event firing signal by the NPT, it is not possible to determine which cycle the NPT time value is in relation to the STC and the NPT, and the data broadcasting is performed. It is possible to perform appropriate transmission and reception.

According to a fifth aspect of the present invention, the NPT reference signal and the NP
In a data broadcast receiving apparatus provided with a means for receiving an event firing signal due to T, when performing NPT stepping based on the received NPT reference signal,
An STC maximum value (STCma) during a future time (STCw2) by a predetermined value in a range where NPTs are continuous.
In the case where x) is visited, the NPT is provided with a means to continuously advance even if there is a discontinuity in which the STC returns to zero after the STC maximum value.

According to the fifth aspect of the present invention, the NPT used in the data broadcasting continuously advances near the discontinuous point where the current STC returns to zero, for example, without returning the NPT to zero. Therefore, it is possible to prevent a problem that the event message cannot be fired based on the NPT discontinuity.

In the data broadcast transmitting method according to the present invention, when transmitting the NPT reference signal, the STC value (STCr) as the reference source is always the current STC value (STCr).
Cc), in a range in which the NPT is continuous, setting a predetermined value (STCw) in the range of the past (STCw1) or the future (STCw2), and an NPT reference signal and an event firing signal by the NPT. And sending the data.

According to the sixth aspect of the present invention, in the transmission of the NPT reference signal, the relationship between the STC and the NPT is as follows:
It is possible to solve the problem that the STC time value of which cycle is not known, and it is possible to perform appropriate transmission and reception in data broadcasting.

In the data broadcast transmission method according to the present invention, when transmitting an event firing signal by NPT, a valid firing designation NPT value is always set to a current STC value (S
TCc), a step of setting a future value (STCw2) by a predetermined value in a range in which NPT is continuous to a range of values obtained by NPT conversion, and an NPT reference signal and NP
Sending an event firing signal by T.

According to the seventh aspect of the present invention, in the transmission of an event firing signal by the NPT, it is possible to solve the problem that it is not possible to determine which cycle the NPT time value is in relation to the STC and the NPT, and the data broadcasting is performed. It is possible to perform appropriate transmission and reception.

In the data broadcast receiving method according to the present invention, the step of receiving the NPT reference signal and the event firing signal based on the NPT, and the step of performing the NPT step based on the received NPT reference signal, are performed based on a current STC value. NP
When the STC maximum value (STCmax) comes during a future time (STCw2) by a predetermined value in a range where T is continuous, even if there is a discontinuity in which the STC returns to zero after the STC maximum value, the NPT becomes Continuously stepping.

According to the eighth aspect of the present invention, the NPT used in the data broadcasting continuously advances near the discontinuity point where the current STC returns to zero, for example, without returning the NPT to zero. Therefore, it is possible to prevent a problem that the event message cannot be fired based on the NPT discontinuity.

[0026]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of a digital broadcasting system according to the present invention.

In the digital broadcasting system shown in FIG. 1, on the transmitting side, video data and audio data obtained from the image pickup device 11 are input to the MPEG encoder 12 and the encoder 13 encodes (compresses and encodes) the data by the MPEG system. Generate In FIG. 1, the MPEG encoder 12
It operates with a clock (27 MHz) from one clock generator. The encoded data from the MPEG encoder 12 includes PCR as reference time information from the PCR unit 13.
(Program Clock Reference: a program clock reference value) is added by the adder 14 and sent to the multiplexing circuit 15. The PCR section 13 is for adding the time information lost by the encoding of the MPEG encoder 12 to the encoded data, and transmits a value obtained by counting the transmission side clock of 27 MHz by the STC counter at a predetermined cycle. The receiver has a 27 MHz clock generation circuit 27 which generates a 27 MHz clock by periodically comparing and referring to the incoming PCR, and the value of the STC counter on the receiver is intended by the MPEG encoder. Set and calibrate to the set value. Then, the encoded data to which the PCR is added is multiplexed with other encoded data by a multiplexing circuit.
The signal is multiplexed at 15 and sent to the modulation circuit 16, where the carrier is digitally modulated and transmitted from the antenna 17 to the satellite 20. A microcomputer (CPU for operation control, R for program)
OM and data RAM)
Reference numeral 18 controls the MPEG encoder 12, the multiplexing circuit 15, and the modulation circuit 16, and has functions necessary for transmitting a data service of data broadcasting.
It has a counting function, an NPT time designation function, and the like.

In the satellite 20, the transmitted digital modulated wave is amplified by a transponder and retransmitted. On the receiving side, the carrier wave by the digital modulation wave is received by the antenna 31 and supplied to the digital broadcast receiving device 30.

The digital broadcast receiving apparatus 30 receives and demodulates a digitally modulated wave transmitted by a carrier wave of a predetermined frequency by a demodulation circuit (including a tuner) 32 and supplies the demodulated signal stream to a demultiplexing circuit 33. Then, one program data is selected (separated) from the stream, the video data and the audio data are decoded by the MPEG decoder 34 in the MPEG system, and the MPEG-decoded video signal and the audio signal are transmitted to the TV receiver 36. Output and play. MP
The STC unit 35 is connected to the EG decoder 34. STC
The unit 35 counts the 27 MHz clock generated with reference to the PCR coming from the transmitting side, and
This is for performing the MPEG decoding process at the same timing as the G encoding process. A control unit 37 composed of a microcomputer (including an arithmetic control CPU, a program ROM, and a data RAM) controls the demodulation circuit 32, the demultiplexing circuit 33, and the MPEG decoder 34. Data storage, reception, and communication functions required to receive data broadcasting data services
In addition to having a presentation function, it has an NPT counting function and the like. The NPT counting function is equivalent to a 33-bit counter.

Here, a case will be described in which an explanation screen corresponding to a scene linked to a digital broadcast program is transmitted by data broadcast. For example, when a certain screen is viewed while watching a movie program (this screen can be considered as a scene corresponding to a specific time in a standard full movie playback time), the description of the specific screen is simultaneously displayed. The case will be described. As shown in FIG. 2, the standard total playback time of the movie body is 2 hours, and if a CM is added as an event during the playback time, the actual broadcast time of this movie program (ie, the actual time by the STC count) Is 2 hours + CM time. However, on the receiving side, the time counting by the NPT is stopped by the NPT reference message from the transmitting side for the CM period, and only the reproduction time of the movie body is counted. After that, it is assumed that the transmitting side has transmitted a time designation NPT1 by NPT for displaying an explanation screen for a specific screen.

Next, referring to the above example, the transmission of the NPT reference message will be described with reference to FIG. FIG.
Indicates an association between the STC and the NPT. this is,
This is related to the description in “5.3.4.4. Transmission of NPT reference message” in ARIB TR-B15. The horizontal axis is the STC time axis, and the vertical axis is the NPT time axis. As described above, the NPT reference message is transmitted from the transmitting side to notify the receiver of the association between the NPT and the STC.

The descriptor of the NPT reference message sent from the transmitting side is represented by (STC value, NPT value, NPT value increase / STC value increase).

In FIG. 3, a movie program is started when the STC count is 100. At this time (point a in the figure), (100, 0, 1/1) is transmitted from the transmitting side as an NPT reference message. When the receiver receives this, it stores the rule that the STC count is 100, the NPT count is 0, and the STC increases by 1 to increase the NPT by 1, and the movie program proceeds according to the rule. The above NPT reference descriptor (100, 0, 1/1) is sent from the transmitting side to the receiving side every second. And the STC count corresponding to point b is
At the time of 500 (2 seconds before actually becoming 500), the transmitting side sends an NPT reference descriptor (500, 400, 0/1). This means that when the STC count reaches 500 and the NPT count reaches 400, the NPT value increase is set to 0 (that is, an instruction to stop the progress of the movie program), and 0 /
During the period 1, a CM is inserted instead of a movie program. Then, when the STC count corresponding to the point c is 700 (actually, 2 seconds before reaching 700), the NPT reference descriptor (700, 400, 1/1) is transmitted from the transmitting side. When the receiver receives this, the STC count is increased from 700 and the NPT count is increased from 400, and the movie program continues to be resumed from the interrupted state and proceeds according to the rule that when the STC increases by 1, the NPT increases by 1. Then, when a program is progressing with the NPT reference descriptor (700, 400, 1/1), an event message called NPT1 (for example, NP
An instruction to display an explanation screen when the time T1 comes) is given (marked by X in FIG. 3), and the receiver receives and takes it in. When the execution time NPT1 shown on the NPT time axis comes, the data The explanation screen received by broadcasting is output on the movie program screen.

In data broadcasting in such a digital broadcasting system, the relationship between STC and NPT is shown in FIG.
It is shown as follows. In FIG. 4, as in FIG.
C is reset (= 0) for each count value corresponding to a fixed time (time for one round) T, and the repetition of each reset of the STC is extended in the horizontal axis direction and is represented as a repetitive waveform. First, one of the conventional problems will be described with reference to FIG.

The transmitting side sends (1) an NPT reference message (hereinafter referred to as an NPT reference signal) for associating the STC with the NPT as described in FIG.
(2) Consider a case where an event message (hereinafter, referred to as an event firing signal) NPT1 by NPT is sent.

(1) For example, an NPT reference signal is transmitted from the transmission side, and the reception side receives the NPT reference signal at time A (see FIG. 4) (this reception time is almost equal to the time transmitted from the transmission side), and receives it. Message content is the current S
It is assumed that a time B which is earlier than the time A of the TC is specified, and the control is performed at the time B. In such a case, there is a problem that the receiver cannot know whether the time to be controlled is point B, point C in the previous cycle, or point D in the next cycle.
For example, when interpreting as point D in the next cycle, STC1
Control is performed at a time earlier than the number of laps.

(2) Further, for example, an event firing signal NPT1 is sent from the transmitting side, and the receiver receives it at time E (see FIG. 4) (the received time is almost equal to the time sent from the transmitting side). Assume that the content of the received message is to execute an instruction at a point F in the future (see FIG. 4) (that is, to fire at the time F). In such a case, the receiver does not know whether the instruction execution time (time to fire) is the point F, the point G in the previous cycle, or the point H in the next cycle. There's a problem. For example, H in the next cycle
If it is interpreted as a point, it will be executed at a time earlier than one round of the STC.

[First Embodiment] Then, the above (1)
As a solution to the above problem, the range of the STC value (STCr) as a reference source that can be specified by the NPT reference signal is set to a certain width (range) with respect to the current STC value (STCc) as shown in FIG. Make it possible to specify only the values you have. For this purpose, as shown in FIG. 4, a range W (hereinafter referred to as a window W) including a past range W1 and a future range W2 around the current STC value (STCc) is set.

In transmitting the NPT reference signal, the STC value (STCr) serving as the reference source of the NPT reference signal is included in the window W. That is, the transmitted N
Before the STCr of the PT reference signal goes out of the window,
A new NPT reference signal that meets the above conditions is transmitted. Window W has a current STC value (ST
Along with Cc), it moves on the STC time axis while maintaining a certain range W around the current STC value (STCc). However, the sum W of the time frames set in the past (W1) and the future (W2) with respect to the present (that is, the window W) does not exceed the STC maximum value (STCmax). Further, the effective ranges W1 and W2 of the STC time pointed to by the NPT reference signal need to be set within a time period during which the NPT is continuous. Since the same STC value (STCr) is never taken in the range of the frame of the window W, the problem that the user cannot know which cycle time is specified as described in the above (1) is solved. You. If the STC counter configured in the control unit 18 is 33 bits, the STC maximum value (STCma
x) is 2 ³³ −1, so the window W in that case is
Is within a range not exceeding (2 ³³ -1).

Therefore, in the first embodiment of the present invention, the control unit 18 on the transmitting side has a means for transmitting an NPT reference signal and an event firing signal based on the NPT to the receiver, and transmits the NPT reference signal to the receiver. When transmitting, the STC value (STCr) as the reference source is always the current STC value.
The value (STCw) is a predetermined value (STCw) in the range where the NPT continues with respect to the value (STCc).
1) Or a configuration including means for setting the value to be in the range of the future value (STCw2). Here, the predetermined value (STCw) means the width of the window W corresponding to the sum of the past value (STCw1) and the future value (STCw2).

[Second Embodiment] As a solution to the above-mentioned problem (2), when an event firing signal is transmitted by the NPT, an effective firing designation NP
The T value is entered. In other words, it waits until a valid firing designation NPT value to be designated enters the window W, and then indicates the NPT value. The window W includes the current STC value (STCc) together with the current STC value as shown in FIG.
A predetermined future time W2 determined in advance from the C value (STCc)
(That is, the window W) is kept and moves on the STC time axis. However, the time frame W2 (that is, the window W) set in the future with respect to the present does not exceed the STC maximum value (STCmax). The effective range W2 of the NPT time pointed by the event firing signal is NP
It is necessary that T be set within a continuous time. In the range of such a window W frame, the same NPT
Since the value is never taken, the problem described in (2) above that the user cannot know which cycle time is specified is solved. If the STC counter configured in the control unit 18 is 33 bits, the STC maximum value (S
(TCmax) is 2 ³³ −1, and the width of the window W in that case is within a range not exceeding (2 ³³ −1).

Accordingly, in the second embodiment of the present invention, the control unit 18 on the transmitting side has a means for transmitting an NPT reference signal and an event firing signal based on NPT to the receiver, and also includes an event firing based on NPT. When transmitting a signal, always set a valid firing designation NPT value to the current STC
With respect to the value (STCc), there is provided a means for setting a future value (STCw2) by a predetermined value within a range in which NPT is continuous in a range of values converted into NPT. The future value (STCw2) by a predetermined value means the window W. In the second embodiment, the past value (STCw1) in the first embodiment is set to 0, and the predetermined value (STCw) is set to only the future value (STCw2).

[Third Embodiment] On the other hand, the STC shown in FIG.
As described in the relationship between the NPT and the NPT, the NPT used in the data broadcasting is near a discontinuous point where the current STC value returns to zero, so that the NPT also returns to zero, so that the NPT becomes a dead zone and the event message cannot be fired. There was a problem.

Therefore, in the present application, as a solution, only a value having a certain width (range) with respect to the current STC value (STCc) can be specified as shown in FIG.
For this purpose, the transmitting side sets a future time W2 (ie, window W) by a predetermined value from the current STC value (STCc) as shown in FIG. The window W displays the current STC value (STCc) together with the current STC value (STCc).
STC while maintaining a predetermined time W2 in the future from c)
It moves on the time axis. However, the time frame W2 set in the future with respect to the present is the STC maximum value (STC
max). Incidentally, if the STC counter is 33 bits configured in the control unit 18, since the STC maximum value (STCmax) is ² 33 -1, the width of the window W in this case does not exceed ⁽² 33 -1) Range. Further, the effective range W2 of the NPT time pointed by the NPT reference signal needs to be set within a time period in which the NPT is continuous. On the other hand, on the receiving side, the received NPT
When performing the NPT step based on the reference signal, during the predetermined future time W2 from the current STC value,
If the TC maximum value (STCmax) comes,
Even if there is a discontinuity where STC returns to zero after the maximum value, NPT
Is to be continuously advanced.

The NPT step will be described with reference to FIG. 6 using a movie program as an example. The solid line in FIG.
At the discontinuity point where C returns to zero, the NPT continuously advances without returning to zero. Consider from the start of the movie (= 0) to the end of the movie on the NPT time axis. When the movie starts when the STC has a certain value (start point), the STC
As the value elapses, the NPT value increases from 0,
When the STC counter reaches the maximum value (STCmax),
The STC value is reset to 0. At this time, in the related art, for example, the NPT value is also reset to return to 0, but in the embodiment of the present invention, the NPT value is continuously advanced without resetting even if the STC value is reset. Control. This is equivalent to the case where the NPT proceeds continuously as shown by the dotted line in FIG.

Therefore, in the third embodiment of the present invention, the control section 37 on the receiving side has a means for receiving the NPT reference signal and the event firing signal by the NPT, and has the NPT step based on the received NPT reference signal. In performing the advance, the STC maximum value (S
If TCmax) is reached, ST
Even if there is a discontinuity in which C returns to zero, the NPT has a structure provided with means for continuously moving forward.

In this manner, the NPT used in the data broadcasting is continuously advanced without returning to 0 at the discontinuity point where the current STC returns to zero. It is possible to eliminate the problem that the event message cannot be fired based on the event message.

[0048]

As described above, according to the present invention, the current STC is used for the NPT used in the data broadcasting.
In the vicinity of the discontinuity point at which the NPT returns to zero, the NPT continuously advances without returning to 0, so that it is possible to prevent the event message based on the NPT discontinuity from being fired. Further, in the transmission of the NPT reference signal and the event firing signal by the NPT, it is possible to solve the problem that the STC and the NPT time value of the cycle are not known in relation to the STC and the NPT, and it is possible to solve the problem in the data broadcasting. Transmission and reception are possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of a digital broadcasting system according to the present invention.

FIG. 2 is a diagram illustrating a time schedule when an explanation screen is transmitted by data broadcasting in conjunction with a digital broadcast program.

FIG. 3 is a diagram showing a method of transmitting an NPT reference message.

FIG. 4 is a view for explaining the operation of the data broadcast transmitting apparatus according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating an operation of the data broadcast transmitting device according to the second embodiment of the present invention.

FIG. 6 is a diagram illustrating an operation of the data broadcast receiving device according to the third embodiment of the present invention.

FIG. 7 is an STC used in a digital broadcast transmitting / receiving apparatus.
The figure which shows the count value of a counter.

FIG. 8 is a diagram showing a relationship between STC and NPT.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Digital broadcast transmitting apparatus (including a data broadcasting transmitting function) 18 ... Control part (receiving side) 30 ... Digital broadcasting receiving apparatus (including a data broadcasting receiving function) 37 ... Control part (transmitting side)

Claims (16)

[Claims] 1. A data broadcast transmitting apparatus having means for transmitting an NPT reference signal and an event firing signal based on the NPT, wherein when transmitting an NPT reference signal, an STC value (STCr) as a reference source is always set to a current STC value. Value (STC
With respect to c), there is provided a means for setting a predetermined value (STCw) within a range of a past value (STCw1) or a future value (STCw2) by a predetermined value (STCw) in a continuous range of NPT. Data broadcasting transmitting device. 2. A data broadcast transmitting apparatus comprising means for transmitting an NPT reference signal and an event firing signal based on an NPT. In transmitting an event firing signal based on an NPT, a valid firing designation NPT value is always set to a current STC value ( STC
A data broadcast transmitting device comprising: a means for setting a value in the future in which NPT is continuous (STCw2) by a predetermined value in a range in which NPT is continuous, to a range of values converted into NPT. 3. A data broadcast receiving apparatus for receiving a broadcast transmitted by the data broadcast transmitting apparatus according to claim 1. 4. A data broadcast receiving apparatus for receiving a broadcast transmitted by the data broadcast transmitting apparatus according to claim 2. 5. A data broadcast receiving apparatus comprising: means for receiving an NPT reference signal and an event firing signal based on the NPT. In performing the NPT step based on the received NPT reference signal, the NPT is continuously calculated based on the current STC value. If the maximum STC value (STCmax) comes during a future time (STCw2) by a predetermined value within the range
Even if there is a discontinuity where the STC returns to zero after the C maximum value, NP
T is a data broadcast receiving device comprising means for continuously stepping. 6. When transmitting an NPT reference signal, the STC value (STCr) from which the NPT reference signal is referenced is always the current STC value.
The C value (STCc) is a predetermined value (STCw) in the range where the NPT continues, and is a value (STCw)
w1) or a value in the future (STCw2), and a step of transmitting an NPT reference signal and an event firing signal based on the NPT. 7. When sending an event firing signal by the NPT, a valid firing designation NPT value is always set to the current ST value.
For the C value (STCc), a future value (STCw2) by a predetermined value in the range where
A data broadcast transmission method, comprising: setting a value within a range of converted values; and transmitting an NPT reference signal and an event firing signal based on the NPT. 8. A step of receiving an NPT reference signal and an event firing signal based on the NPT, and performing an NPT step based on the received NPT reference signal, from a current STC value to a predetermined value in a range where the NPT is continuous. If the STC maximum value (STCmax) comes during the future time (STCw2), ST
Even if there is a discontinuity where the STC returns to zero after the C maximum value, NP
A method of receiving data broadcast, comprising: T continuously stepping. 9. When NPT is continuous, the sum of the past value (STCw1) and the future value (STCw2) is S
3. The data broadcast transmitting apparatus according to claim 1, wherein the maximum value STCmax of the TC is not exceeded. 10. When NPT is continuous, the sum of the past value (STCw1) and the future value (STCw2) is S
The data broadcast receiving apparatus according to claim 3, wherein the data does not exceed a maximum value STCmax that the TC can take. 11. When NPT is continuous, the sum of the past value (STCw1) and the future value (STCw2) is S
8. The data broadcast transmission method according to claim 6, wherein the maximum value STCmax of the TC is not exceeded. 12. When NPT is continuous, the sum of the past value (STCw1) and the future value (STCw2) is S
9. The data broadcast receiving device according to claim 8, wherein the maximum value STCmax of the TC is not exceeded. 13. The NPT is a time when a program or content is normally reproduced, the STC corresponds to an actually elapsed time (real time), and the NPT reference signal uses the NPT as time designation. NPT and S
Relationship with TC (STC value, NPT value, NPT value increase /
STC value increase).
TCr is an STC value in the NPT reference signal,
10. The data broadcast transmitting apparatus according to claim 1, wherein the STCc is a current STC value. 14. The NPT is a time when a program or a content is normally reproduced, the STC corresponds to an actually elapsed time (real time), and the NPT reference signal uses the NPT as time designation. NPT and S
Relationship with TC (STC value, NPT value, NPT value increase /
STC value increase).
TCr is an STC value in the NPT reference signal,
11. The data broadcast receiving device according to claim 3, wherein the STCc is a current STC value. 15. The NPT is a time when a program or content is normally reproduced, the STC corresponds to an actually elapsed time (real time), and the NPT reference signal uses the NPT as time designation. NPT and S
Relationship with TC (STC value, NPT value, NPT value increase /
STC value increase).
TCr is an STC value in the NPT reference signal,
The method according to any one of claims 6, 7, and 11, wherein the STCc is a current STC value. 16. The NPT is a time when a program or content is normally reproduced, the STC corresponds to an actually elapsed time (real time), and the NPT reference signal uses the NPT as time designation. NPT and S
Relationship with TC (STC value, NPT value, NPT value increase /
STC value increase).
13. The data broadcast receiving method according to claim 8, wherein TCr is an STC value in the description of the NPT reference signal, and the STCc is a current STC value.