JP3782006B2 - Broadcast data transmission system, broadcast data transmission method, and data conversion apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a broadcast data transmission system, a broadcast data transmission method, and a data conversion device for broadcasting broadcast data composed of a video signal and a data signal broadcasted at a transmitting station at a receiving station.
[0002]
[Prior art]
Conventional analog terrestrial broadcasting employs a system in which a broadcast program broadcast at a central main station or the like is also broadcast at a local local station. On the other hand, digital broadcasting has been started as a new form of broadcasting. In this digital broadcasting, a data broadcasting method for broadcasting contents such as characters, still images, moving images, and programs as digital data is adopted.
[0003]
In this data broadcasting, broadcast data composed of a video signal and a data signal is broadcast in a predetermined band, and a VBR system is adopted as a system for transmitting these data. In this VBR method, a predetermined band is divided into a video signal band and a data signal band, and each signal is transmitted in each band. When the data amount of the video signal decreases, A function for variably adjusting the band such as decreasing the band for the video signal and increasing the band of the data signal is provided.
[0004]
[Problems to be solved by the invention]
However, in the conventional data carousel VBR system, as described above, since the data broadcasting band is variably controlled in accordance with the reduction in the video bit rate, there is a case where video is replaced at a local station such as a local broadcasting station. The VBR-TS from the originating station could not be used as it is.
[0005]
In addition, as another method for transmitting broadcast data, there is a method in which a data signal and a video signal are transmitted through different paths and methods. According to this, it is necessary to synchronize the data signal and the video signal in the local station. However, since the conventional data carousel method is characterized by the lack of time synchronization, time synchronization with the video stream is difficult, and a video data broadcast synchronization method at a local station in terrestrial digital broadcasting has not been established. It was.
[0006]
Therefore, an object of the present invention is to make it possible to use broadcast data broadcast at the main station as it is at the local station, to effectively use the content, and to reduce the burden on the content production at the local station.
[0007]
[Means for Solving the Problems]
The invention according to the present application has been made to solve the above-described problems, and transmits video signals and data signals when transmitting broadcast data composed of video signals and data signals broadcasted at the originating station to the receiving station. Time information on the transmission time to be added to the video signal and the data signal, respectively, the video signal and the data signal are transmitted to the receiving station, and the time information added to the video signal and the data signal is acquired at the receiving station, respectively. The video signal and the data signal are multiplexed at the timing based on the verification result, and the transmission timing of the video signal and the data signal sent on the lines with different transmission speeds is automatically determined by the receiving station according to the transmission time. It is characterized by adjusting. The time information includes, for example, the system time at the originating station and the time calculated based on the system time (real time, NPT (Normal Play Time) time, STC (System Time Clock), PCR (Program Clock).
Reference) or a combination thereof).
[0008]
According to the present invention, time information is added to each of the video signal and the data signal at the originating station, and multiplexing is performed while synchronizing the video signal and the data signal at the receiving station based on this time information. This makes it easy to use broadcast data at the receiving station.
[0009]
In the present invention, received at 受局, it replicated the respective data signals temporarily stored in a plurality of buffer means, based on the time information, the data signal from one of the buffer means of said plurality of buffer means Is output at a fixed rate, a band surplus signal is output when an unused part of the band is detected, and a data signal is output from the buffer means at a variable rate according to the unused part of the band based on the band surplus signal. It is characterized by that.
[0010]
According to the present invention, when the video signal and the data signal are multiplexed at the receiving station, the unused band can be effectively used by using the fixed bit rate and the variable bit rate in combination. .
[0011]
In the present invention, at the originating station, the transmission time unique to the originating station is added to the video signal and the data signal as time information, and at the receiving station, the sending time unique to the receiving station is generated as time information, and in the multiplexing process at the receiving station The time information on the originating side is replaced with the time information on the receiving side.
[0012]
According to the present invention as described above, the transmitting station and the receiving station can perform multiplexing and broadcasting with unique time information, respectively, and can effectively use the contents while adapting to the environment of each station. .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
(Configuration of data broadcasting system)
Embodiments of the present invention will be described with reference to the drawings. 1 and 2 are explanatory diagrams showing an outline of the data broadcasting method according to the present embodiment.
[0014]
As shown in FIG. 1, the broadcast data transmission system according to the present embodiment transmits broadcast data between an originating station 1 that is a key station and a receiving station 2 that is a local station. Specifically, the originating station 1 includes a real time generator 11, an STC generator 12, an SDI auxiliary signal encoder 13, an NPT time generator 14, an NPT reference descriptor generator 15, a video encoder 16, And a data broadcast stream packetizer 17.
[0015]
The real time generator 11 measures the absolute time and outputs the transmission time to the SDI auxiliary signal encoder 13 and the NPT time generator 14 as time information. The STC generator 12 measures an STC (System time clock) that is a system time unique to the system of the originating station 1 and outputs the STC value to the NPT reference descriptor generator 15 and the video encoder 16.
[0016]
The SDI auxiliary signal encoder 13 adds real time to the SDI auxiliary signal area included in the video signal, and the real time added to the SDI auxiliary signal area is output to the video encoder 16.
[0017]
The NPT time generator 14 generates an NPT time based on the time information input from the real time generator 11, and this NPT time is output to the NPT reference descriptor generator 15. The NPT reference descriptor generator 15 generates an NPT reference descriptor based on information from the NPT time generator 14 and the STC generator 12. The NPT reference descriptor is correspondence table data that associates the NPT time with the STC. Then, the generated NPT reference descriptor is output to the data broadcast stream packetizer 17. In this NPT reference descriptor generator 15, the NPT time is the same as the actual transmission time.
[0018]
The video encoder 16 encodes and converts the video signal into a broadcastable MPG-2TS, and the converted TS is broadcast via the multiplexer 18 and transmitted to the receiving station 2. In addition, the video encoder 16 generates a PCR (Program Clock Reference) and outputs it to the data broadcast stream packetizer 17. The video encoder 16 has a function of adding the STC generated by the STC generator 12 to the encoded video signal.
[0019]
The data broadcast stream packetizer 17 packetizes the data broadcast stream in a broadcastable format, sends the packet through the multiplexer 18 and transmits the packet to the receiving station 2. The NPT reference descriptor generator 15 The NPT reference descriptor input from the video encoder 16 and the PCR from the video encoder 16 are multiplexed and converted to a TS. The multiplexer 18 multiplexes signals from the video encoder 16 and the data broadcast stream packetizer 17 and broadcasts them to the receiver in the service area of the originating station.
[0020]
On the other hand, the receiving station 2 includes a video decoder 22, an SDI auxiliary signal decoder 23, a video encoder 24, an STC generator 25, a multiplexer 26, and a VBRTS buffer 21.
[0021]
The video decoder 22 decodes and converts the encoded data transmitted from the originating station 1, and sends the converted video to the SDI auxiliary signal decoder 23. The SDI auxiliary signal decoder 23 decodes the SDI auxiliary signal included in the composite video signal, extracts the time information included in the SDI auxiliary signal, and uses this as a read NPT value as the VBRTS buffer 21. Output to. The video encoder 24 re-encodes the video signal that has been decoded and converted, and this encoding depends on the conversion rate and the system time determined independently by the receiving station 2.
[0022]
The STC generator 25 generates a net station master STC that is an STC unique to the receiving station 2 and outputs it to the VBRTS buffer 21. The multiplexer 26 multiplexes the video signal encoded by the video encoder 24 to generate a TS that can be broadcast. The multiplexer 26 transmits a band surplus signal for each service when there is a margin in the band of the broadcast service.
[0023]
The VBRTS buffer 21 buffers the data broadcast stream transmitted from the originating station 1 and converts it into a VBR suitable for the receiving station 2. The VBRTS buffer 21 according to the present embodiment includes a TS separation unit 31, an original STC playback unit 32, an NPT playback unit 33, a TS buffer 34, a carousel buffer 35, a local station PCR generation unit 36, and an STC replacement unit 37. And a TS synthesis unit 38.
[0024]
The TS separation 31 separates the data broadcast stream transmitted from the originating station 1 into a PCR, an NPT reference descriptor, a data carousel, and an event message.
[0025]
The original STC reproduction unit 32 generates an STC in the originating station 1 based on the PCR input from the TS separation unit 31, and outputs this to the NPT reproduction unit 33 and the TS buffer 34 as an STC value.
[0026]
The NPT playback unit 33 collates the NPT reference descriptor based on the STC value of the originating station 1 input from the original STC playback unit 32, and generates an NPT value corresponding to the input STC value. The generated NPT value is output to the TS buffer 34. In addition, the NPT playback unit 33 sends the NPT reference descriptor received from the TS separation unit 31 to the STC replacement unit 37.
[0027]
The TS buffer 34 reads the data carousel from the TS separation unit 31 based on the STC value from the original STC reproduction unit 32 and the read NPT value from the NPT reproduction unit 33 and the SDI auxiliary signal decoder 23. This data carousel is sent to the TS synthesis unit 38.
[0028]
Specifically, the TS buffer 34 stores a plurality of data carousels ES from the TS separation 31 in a section data format. At this time, the original STC value and the NPT value are recorded as attribute values in the section data. Then, the TS buffer 34 compares the read NPT value input from the SDI auxiliary signal decoder 23 with the NPT value of the originating station 1, which is the attribute value of the PES recorded in the TS buffer, and outputs matching section data. . If there is no PES having a matching NPT value, a null packet is output.
[0029]
The carousel buffer 35 converts the data carousel separated by the TS separation unit 31 into a VBR (variable bit rate). The data carousel converted to VBR is sent to the TS synthesis unit 38. Specifically, the carousel buffer 35 separates the data carousel ES for each ES, stores each ES in a buffer in a section format according to the module ID, and receives a band surplus signal from the multiplexer 26. The section is sent to the TS synthesis unit 38 according to the rule according to the signal. This band surplus signal is transmitted when an unused band is detected in the multiplexer 26. The multiplexer 26 monitors NUL data in the data transmitted from the TS combiner 26, and An unused band is detected, and a band surplus signal corresponding to the unused band amount is sent to the carousel buffer 35.
[0030]
More specifically, this section is sent in accordance with the DII included in the section. First, the carousel buffer 35 extracts the DII in the section, acquires the module configuration of the data carousel, and stores the module ID as an attribute value in the buffer. When the carousel buffer 35 detects a change in the transaction ID of the DII transmitted by the ES, the carousel buffer 35 determines that the contents of the carousel have been updated, and clears the data in the buffer.
[0031]
The local station PCR generation unit 36 generates a PCR unique to the receiving station 36, and generates a PCR based on the net station master STC input from the STC generator 25. The STC replacement unit 37 changes the NPT reference descriptor from the NPT playback unit 33 based on the net station master STC from the STC generator 25 and outputs it to the TS synthesis unit 38.
[0032]
The TS synthesizing unit 38 synthesizes the TS from the PCR, NPT reference descriptor, data carousel, and event message sent from each of the above units, and the synthesized TS is output to the multiplexer 26.
[0033]
(Operation)
The broadcast data transmission system according to this embodiment having the above-described configuration operates as follows.
[0034]
First, when a video signal is input at the originating station 1, real-time information is added to the SDI auxiliary signal at the SDI auxiliary signal encoder 13, and the video signal is encoded at the video encoder 16. At the time of this encoding, the DTS value and PTS value obtained from the STC are added. In addition, a PCR value is generated in synchronization with the encoding of the video signal, and this is input to the data broadcast stream packetizer 17.
[0035]
On the other hand, for the data signal, first, an NPT value is generated from real-time information in the NPT time generator 14 and input to the NPT reference descriptor generator 15, and the STC value generated by the STC generator 12 is The NPT reference descriptor generator 15 inputs the NPT reference descriptor, which is a correspondence table between NPT and STC.
[0036]
This NPT reference descriptor is input to the data broadcast stream packetizer 17. The data broadcast stream packetizer 17 packetizes the data signal after adding the NPT reference descriptor and the PCR value to the data signal.
[0037]
The video signal encoded by the video encoder 16 is transmitted to the receiving station 2 at a fixed bit rate or a variable rate, and is input to the multiplexer 18. Further, the data signal packetized by the data broadcast stream packetizer 17 is transmitted to the receiving station 2 by CBR and input to the multiplexer 18. In the multiplexer 18, the video signal and the data signal are multiplexed and broadcast.
[0038]
The video signal transmitted to the receiving station 2 is decoded by the video decoder 22 and the SDI auxiliary signal decoder 23 extracts the SDI auxiliary signal. The SDI auxiliary signal decoder 23 obtains real time information from the extracted SDI auxiliary signal, generates an NPT value based on the real time information, and inputs the NPT value to the VBRTS buffer 21. Thereafter, the video signal is encoded by the video encoder and input to the multiplexer 26.
[0039]
On the other hand, the data signal transmitted to the receiving station 2 is input to the VBRTS buffer 21. In this VBRTS buffer 21, it is separated into PCR, NPT reference descriptor, data carousel and event message.
[0040]
The PCR is input to the original STC playback 32, where an STC value is generated, and this STC value is input to the NPT playback unit 33 and the TS buffer 34, respectively. The NPT reference descriptor is input to the NPT playback unit 33. The NPT playback unit 33 collates the NPT reference descriptor with the STC value to generate an NPT value, and this NPT value is input to the TS buffer 34. Further, the NPT playback unit 33 transfers the NPT reference descriptor to the STC replacement unit 37.
[0041]
The data carousel is duplicated and input to the TS buffer 34 and the carousel buffer 35. The TS buffer 34 accumulates the received data carousel in the buffer, and also stores the accumulated data carousel on the basis of the NPT value from the NPT playback unit 33 and the NPT value from the SDI auxiliary signal decoder 23. Output to.
[0042]
The carousel buffer 35 accumulates the received data carousel in the buffer and outputs the accumulated data carousel to the TS synthesizing unit 38 at a variable bit rate according to the band surplus signal from the multiplexer 26.
[0043]
Specifically, when the carousel buffer 35 receives a band surplus signal from the multiplexer 26, the carousel buffer 35 transmits sections in the following order and rule based on the presence or absence of DII (Data Information Initiative) in the carousel.
[0044]
(1) When DII has been acquired If DII is present in the data carousel and has already been acquired in the carousel buffer 35, first, DII is sent to the TS synthesis unit 38, followed by DDB. (DDI description order) is sent out. When this DDB is sent, the last sent DDB (final send DDB) is stored in the memory (final send DDB memory). When the next DDB is sent, the DDB for the module closest to and larger than the value of the last send DDB memory is sent.
[0045]
Thereafter, when the largest module ID (final DDB) described in DII matches the module ID of the final transmission DDB, DDI is transmitted and the final transmission DDB memory is set to NUL. In addition, DII is transmitted at a period defined in the broadcast operation regulations.
[0046]
(2) When the DII is not acquired On the other hand, when the DII does not exist and the DII is not acquired, the acquired modules are transmitted in the order of acquisition.
[0047]
The event message passes through the buffer and is directly input to the TS synthesis unit 38.
[0048]
(effect)
According to the broadcast data transmission system according to the present embodiment described above, time information (STC value, NPT value, PCR value) is added to each of the video signal and the data signal at the originating station 1, and based on this time information. Since the receiving station 2 can perform multiplexing while synchronizing the video signal and the data signal, the broadcast data in the receiving station 2 can be easily used.
[0049]
In the present embodiment, when the video signal and the data signal are multiplexed in the receiving station 2, the data carousel is converted to a variable bit rate by the carousel buffer 35, so that an unused band can be effectively used. it can.
[0050]
Furthermore, in the present embodiment, the STC reassigning unit 37 reassigns the system time information (STC value) of the NPT reference descriptor to the unique time information of the originating station 1 and the unique time information of the receiving station 2. Thus, multiplexing and broadcasting can be performed, and content can be effectively used while adapting to the environment of each station.
[0051]
【The invention's effect】
As described above, according to the present invention, it is possible to use broadcast data broadcast at the main station as it is at the local station, to effectively use the content, and to reduce the burden on content production at the local station. Can do. Further, according to the present invention, since the video signal and the data signal can be synchronized between the originating station and the receiving station, the use of content by the receiving station can be facilitated.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a broadcast data transmission system according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of a VBRTS buffer in the broadcast data transmission system according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Origination station, 2 ... Reception station, 11 ... Real time generation part, 12 ... STC generation part, 13 ... SDI auxiliary signal encoder, 14 ... NPT time generator, 15 point NPT reference descriptor generator, 16 ... Video encoder , 17 ... Data broadcast stream packetizer, 18 ... Multiplexer, 21 ... VBRTS buffer, 22 ... Video decoder, 23 ... SDI auxiliary signal decoder, 24 ... Video encoder, 25 ... STC generator, 26 ... Multiplexer

Claims (9)

A broadcast data transmission system for transmitting broadcast data composed of a video signal and a data signal broadcast at a station to a receiving station,
Time information adding means for adding time information related to a transmission time for sending the video signal and the data signal to the video signal and the data signal, respectively.
Means for transmitting the video signal and the data signal to the receiving station;
Means for acquiring each time information added to the video signal and the data signal at the receiving station, and collating these time information;
Multiplexing means for multiplexing the video signal and the data signal at a timing based on the collation result;
A broadcast data transmission system, comprising: means for automatically adjusting a transmission timing of a video signal and a data signal transmitted through lines having different transmission speeds according to a transmission time. A plurality of buffer means for temporarily storing each of the replicated data signals received at the receiving station;
Means for outputting a data signal at a fixed rate from any one of the plurality of buffer means based on the time information;
Means for outputting a band surplus signal when an unused portion of the band is detected;
Based on the bandwidth excess signal, claim 1 of the data signal from the other buffer means of said plurality of buffer means, characterized in that it has a means for outputting at a variable rate in accordance with the unused amount of the band Broadcast data transmission system described in 1 . In the originating station, the originating side time generating means for adding the transmission time unique to the originating station to the video signal and the data signal as time information,
In the receiving station, a receiving side time generating means for generating a receiving time unique to the receiving station as time information,
The broadcast data transmission system according to claim 1, further comprising means for replacing the time information on the originating station side with the time information on the receiving station side in the multiplexing process by the multiplexing means in the receiving station. There is a broadcast data transmission method for broadcasting broadcast data consisting of a video signal and a data signal broadcast at a station, at a receiving station,
Adding time information related to a transmission time at which the video signal and the data signal are transmitted at the originating station to the video signal and the data signal, respectively.
Transmitting the video signal and the data signal to another broadcast station;
Obtaining each time information added to the video signal and the data signal in the receiving station, and collating these time information;
Multiplexing the video signal and the data signal at a timing based on the verification result;
A broadcast data transmission method comprising: a step of automatically adjusting a transmission timing of a video signal and a data signal transmitted on lines having different transmission speeds according to a transmission time. Temporarily storing in each of the plurality of buffer means a data signal received and replicated at the other station;
Outputting a data signal at a fixed rate from any one of the plurality of buffer means based on the time information;
Outputting a band surplus signal when an unused portion of the band is detected;
Based on the bandwidth excess signal, according to claim 4 in which the data signal from the other buffer means of said plurality of buffer means, characterized by a step of outputting a variable rate according to the unused amount of the band Broadcast data transmission method described in 1 . At the originating station, adding a transmission time unique to the originating station to the video signal and data signal as time information;
In the receiving station, generating a sending time unique to the receiving station as time information;
5. The broadcast data transmission method according to claim 4, further comprising the step of replacing the time information on the originating station side with the time information on the receiving station side when performing multiplexing processing by the multiplexing means in the receiving station. A data conversion device for converting broadcast data composed of a video signal and a data signal broadcast at a source station so as to be broadcastable at a receiver station,
Means for receiving the video signal and the data signal to which time information relating to a transmission time for transmitting the video signal and the data signal is added, respectively.
Means for acquiring time information added to the video signal and the data signal, respectively, and collating these time information;
A data conversion apparatus comprising: multiplexing means for multiplexing the video signal and the data signal at a timing based on the collation result. A plurality of buffer means for temporarily storing each of the received and replicated data signals;
Means for outputting a data signal at a fixed rate from any one of the plurality of buffer means based on the time information;
Means for outputting a band surplus signal when an unused portion of the band is detected;
Based on the bandwidth excess signal, according to claim 7 in which the data signal from the other buffer means of said plurality of buffer means, characterized in that it has a means for outputting at a variable rate in accordance with the unused amount of the band The data converter described in 1 . Means for acquiring time information unique to the station added to the video signal and data signal at the station;
Means for generating the receiving time specific to the receiving station as time information;
8. The data conversion apparatus according to claim 7, further comprising means for replacing the time information on the originating station side with the time information on the receiving station side in the multiplexing process by the multiplexing means in the receiving station.

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