Abstract:
A digital broadcast protocol conversion system including: a PSIP/PSI extractor for demultiplexing a transport stream of an ATSC broadcast standard to extract PSIP/PSI data; an SI/PSI extractor for demultiplexing a transport stream of a DVB broadcast standard to extract SI/PSI data; a protocol converter for converting the PSIP/PSI data to SI′/PSI′ data corresponding to a broadcast protocol of the DVB broadcast standard or converting the SI/PSI data to PSIP′/PSI′ data corresponding to a broadcast protocol of the ATSC broadcast standard; and a multiplexer for multiplexing the SI′/PSI′ data and the transport stream having the PSIP/PSI data extracted therefrom, or multiplexing the PSIP′/PSI′ data and the transport stream having the PSIP/PSI data extracted therefrom, thereby converting the broadcast protocol between different broadcast standards.

Description:
BACKGROUND OF THE INVENTION 
     (a) Field of the Invention 
     The present invention relates to a system for digital broadcast protocol conversion. 
     (b) Description of the Related Art 
     European countries and the Unites States have respectively adopted ATSC (Advanced Television Systems Committee) and DVB (Digital Video Broadcasting) digital broadcast standards, and hence they use different broadcast protocols for transmission of broadcasting programs and system information. As the broadcast protocol depends on the broadcast system, contents produced in a specific standard cannot be used in a broadcast system of a different standard in the case of full-scale digital broadcasts. 
     In a broadcast system of the ATSC broadcast standard, broadcast programs and system information including electronic program guide (EPG) information and channel information are transmitted by way of MPEG (Motion Picture Experts Group) PSI (Program Specific Information) and PSIP (Program and System Information Protocol) based on the ATSC A/65 standard. Contrarily, in a broadcast system of the DVB broadcast standard, broadcast programs and system information are transmitted by MPEG PSI and SI (System Information) based on the DVB EN 300 468 standard. For conversion of the broadcast protocol between ATSC and DVB, therefore, PSIP, PSI, and SI tables have to be converted according to the system standard. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a system for conversion between the PSIP broadcast protocol of an ATSC broadcasting system and the SI broadcast protocol of a DVB broadcasting system. 
     To achieve the object of the present invention, the present invention is directed to extracting a broadcast protocol from a transport stream and converting and multiplexing the extracted broadcast protocol. 
     In one aspect of the present invention, there is provided a system for digital broadcast protocol conversion that includes a first protocol extractor for demultiplexing a transport stream of an ATSC broadcast standard to extract first PSIP/PSI data as a broadcast protocol; and a second protocol extractor for demultiplexing a transport stream of a DVB broadcast standard to first SI/PSI data as a broadcast protocol. The first PSIP/PSI data and the first SI/PSI data are transferred to a protocol converter. The protocol converter converts the first PSIP/PSI data to second SI/PSI data corresponding to a broadcast protocol of the DVB broadcast standard, or converts the first SI/PSI data to second PSIP/PSI data corresponding to a broadcast protocol of the ATSC broadcast standard. A multiplexer multiplexes the second SI/PSI data and the transport stream having first PSIP/PSI data extracted therefrom, or multiplexes the second PSIP/PSI data and the transport stream having the first SI/PSI data extracted therefrom. 
     Preferably, the system further includes a transport stream analyzer for receiving the transport stream of the ATSC or DVB broadcast standard to determine a broadcast protocol conversion pattern, and sending the transport stream to the first or second protocol extractor. 
     The system further includes a controller for controlling a data transport path according to the broadcast protocol conversion pattern determined by the transport stream analyzer. The data transport path includes a path for sending the transport stream from the transport stream analyzer to the first or second protocol extractor, a path for sending the first PSIP/PSI data or the first SI/PSI data from the first or second protocol extractor to the protocol converter, and a path for sending the second SI/PSI data or the second PSIP/PSI data from the first or second protocol extractor to the multiplexer. 
     The protocol converter further includes a database for storing the first PSIP/PSI data and the first SI/PSI data. Preferably, the protocol converter further includes PSIP, SI, and PSI reconstructors for respectively reconstructing PSIP, SI, and PSI data from the first PSIP/PSI data and the first SI/PSI data stored in the database. Thus the protocol converter further includes a GUI (Graphic User Interface) receiver for receiving use data necessary for reconstruction of the PSIP, SI, and PSI data. 
     In a second aspect of the present invention, there is provided a method for digital broadcast protocol conversion. The digital broadcast protocol conversion method includes: (a) receiving a first transport stream of an ATSC broadcast standard or a second transport stream of a DVB broadcast standard to determine a protocol conversion pattern; (b) extracting, as a broadcast protocol, first PSIP/PSI data from the first transport stream when the protocol conversion pattern is PSIP-to-SI conversion, or extracting first SI/PSI data from the second transport stream when the protocol conversion pattern is SI-to-PSIP conversion; (c) reconstructing the first PSIP/PSI data to a table suitable for a broadcast protocol of the DVB broadcast standard to generate second SI/PSI data, or reconstructing the first SI/PSI data to a table suitable for a broadcast protocol of the ATSC broadcast standard to generate second PSIP/PSI data; and (d) multiplexing the second SI/PSI data and the first transport stream having the first PSIP/PSI extracted therefrom, or multiplexing the second PSIP/PSI data and the second transport stream having the first SI/PSI data extracted therefrom. 
     Preferably, the first PSIP/PSI data and the first SI/PSI data extracted are sorted and stored in a database. 
     In a third aspect of the present invention, there is provided a system for digital broadcast protocol conversion including: a first protocol extractor for extracting a first broadcast protocol representing program information and system information from a first transport stream of a first digital broadcast standard; a second protocol extractor for extracting a second broadcast protocol representing program information and system information from a second transport stream of a second digital broadcast standard; and a protocol converter for reconstructing the first broadcast protocol into a broadcast protocol of the second digital broadcast standard to generate a third broadcast protocol, or reconstructing the second protocol into a broadcast protocol of the first digital broadcast standard to generate a fourth broadcast protocol; and a multiplexer for multiplexing the fourth broadcast protocol and the first transport stream having the first broadcast protocol extracted therefrom by the first protocol extractor, or multiplexing the third broadcast protocol and the second transport stream having the second broadcast protocol extracted therefrom by the second protocol extractor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, serve to explain the principles of the invention: 
         FIG. 1  is a block diagram showing a broadcast protocol conversion system in accordance with an embodiment of the present invention; 
         FIG. 2  is a block diagram showing a conversion processor of the broadcast protocol conversion system in accordance with the embodiment of the present invention; 
         FIG. 3  is a block diagram showing a protocol converter of the broadcast protocol conversion system in accordance with the embodiment of the present invention; and 
         FIG. 4  is a flow chart showing a process of digital broadcast protocol conversion. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description, only the preferred embodiment of the invention has been shown and described, simply by way of illustration of the best mode contemplated by the inventor(s) of carrying out the invention. As will be realized, the invention is capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not restrictive. 
     Hereinafter, a detailed description will be given to a broadcast protocol conversion system and method according to an embodiment of the present invention with reference to the accompanying drawings. 
     Now, the broadcast protocol conversion system according to the embodiment of the present invention will be described with reference to  FIG. 1 . 
       FIG. 1  is a block diagram showing a broadcast protocol conversion system in accordance with the embodiment of the present invention. 
     The broadcast protocol conversion system according to the embodiment of the present invention comprises, as shown in  FIG. 1 , a conversion processor  100  and a modulation controller  200 . The broadcast protocol conversion system further comprises a vestigial side band (VSB) demodulator  300 , an orthogonal frequency division multiplexing (OFDM) demodulator  400 , and a storage unit  500 , for sending a demodulated broadcast transport stream (hereinafter, referred to as “TS”) to the conversion processor  100 ; and a VSB modulator  600 , an OFDM modulator  700 , and a storage unit  800 , for sending or storing the TS output from the conversion processor  100 . 
     More specifically, the VSB demodulator  300  demodulates a digital broadcasting signal produced in the ATSC broadcast standard and received via an antenna, and outputs a broadcast TS of the ATSC broadcast standard. The OFDM demodulator  400  demodulates a digital broadcasting signal produced in the DVB broadcast standard and received via the antenna, and outputs a broadcast TS of the DVB broadcast standard. The storage unit  500  stores the broadcast TS of the ATSC/DVB broadcast standard and sends it to the conversion processor  100 . 
     The conversion processor  100  extracts a broadcast protocol from the broadcast TS of the ATSC/DVB broadcast standard received from the VSB demodulator  300 , the OFDM demodulator  400 , and the storage unit  500 , converts the extracted broadcast protocol, and then outputs the converted broadcast protocol and the rest of the extracted broadcast TS. The modulation controller  200  receives information about the determined output type of the broadcast TS from the conversion processor  100  and controls the output type of the broadcast TS output from the conversion processor  100 . The broadcast TS output from the conversion processor  100  is transferred to the VSB modulator  600 , the OFDM modulator  700 , and the storage unit  800 , under the control of the modulation controller  200 . 
     The VSB modulator  600  modulates the broadcast TS output from the conversion processor  100  in the ATSC standard and sends it to subscribers, while the OFDM modulator  700  modulates the broadcast TS output from the conversion processor  100  in the DVB standard and sends it to the subscribers. The storage unit  800  re-stores the broadcast TS output from the conversion processor  100 , and the storage unit  800  may be physically the same as or different from the storage unit  500 . 
     Now, the conversion processor  100  according to the embodiment of the present invention will be described in detail with reference to  FIG. 2 . 
       FIG. 2  is a block diagram showing the conversion processor of the broadcast protocol conversion system in accordance with the embodiment of the present invention. 
     The conversion processor  100  comprises, as shown in  FIG. 2 , a TS analyzer  110 , a protocol extractor  120 , a protocol converter  130 , and a multiplexer  140 . The protocol extractor  120  comprises a controller  122 , a PSIP/PSI extractor  124 , and an SI/PSI extractor  126 . 
     The TS analyzer  110  analyzes the broadcast TS received from the VSB demodulator  300 , the OFDM demodulator  400 , or the storage unit  500 , to determine a broadcast protocol conversion pattern and to send it to the protocol extractor  120 . More specifically, the TS analyzer  100  determines a protocol conversion pattern from PSIP data, i.e., a broadcast protocol of the broadcast TS produced in the ATSC broadcast that is standard to SI data, i.e., a DVB broadcast protocol, or from SI data, i.e., a broadcast protocol of the broadcast TS produced in the DVB broadcast that is standard to PSIP data. 
     The controller  122  of the protocol extractor  120  controls the I/O of the PSIP/PSI and SI/PSI extractors  124  and  126  according to the conversion pattern determined by the TS analyzer  110 . More specifically, the input broadcast TS is transferred to the PSIP/PSI extractor  124  for PSIP-to-SI conversion, or to the SI/PSI extractor  126  for SI-to-PSIP conversion. 
     The PSIP/PSI extractor  124  demultiplexes the broadcast TS of the ATSC broadcast standard to extract PSIP/PSI data, and sends the extracted PSIP/PSI data to the protocol converter  130  under the control of the controller  122 . Likewise, the SI/PSI extractor  126  demultiplexes the broadcast TS of the DVB broadcast standard to extract SI/PSI data, and sends the extracted SI/PSI data to the protocol converter  130  under the control of the controller  122 . The PSIP/PSI and SI/PSI extractors  124  and  126  send the rest of the broadcast TS other than the PSIP/PSI and SI/PSI data to the multiplexer  140 . 
     When the extracted data are PSIP/PSI, the protocol converter  130  converts PSIP data to SI data to reconstruct PSI data, and outputs the reconstructed PSI data to the multiplexer  140 . When the extracted data are SI/PSI data, the protocol converter  130  converts SI data to PSIP data to reconstruct PSI data, and outputs the reconstructed PSI data to the multiplexer  140 . The multiplexer  140  multiplexes the converted broadcast protocol from the protocol converter  130  and the rest of the broadcast TS having the broadcast protocol extracted therefrom. 
     Next, the protocol converter will be described in detail with reference to  FIG. 3 . 
       FIG. 3  is a block diagram showing the protocol converter of the broadcast protocol conversion system in accordance with the embodiment of the present invention. 
     The protocol converter  130  comprises, as shown in  FIG. 3 , PSI, PSIP, and SI receivers  131 ,  132 , and  133 ; a GUI (Graphic User Interface) receiver  134 ; a database DB  135 ; and PSI, PSIP, and PSI reconstructors  136 ,  137 , and  138 . 
     The PSI receiver  131  analyzes the extracted PSI data from the PSIP/PSI extractor  124  or the SI/PSI extractor  126 , and sends them to the database  135 . The PSIP and SI receivers  132  and  133  analyze the extracted PSIP data from the PSIP/PSI extractor  124  and the extracted SI data from the SI/PSI extractor  126 , respectively, and send them to the database  135 . The GUI receiver  134  receives user data necessary for generation of the PSI/PSIP/SI data from the system operator, and sends them to the database. 
     The database  135  sorts and stores the PSI, PSIP, and SI data received from the PSI, PSIP, and SI receivers  131 ,  132 , and  133 , and the user data from the GUI receiver  135 , according to the respective standards. The PSI, PSIP, and SI reconstructors  136 ,  137 , and  138  receive necessary data from the database to construct a table for the respective standards, and output the table to the multiplexer  140 . 
     For example, for PSIP-to-SI conversion, the SI reconstructor  138  reconstructs the PSIP data received from the PSIP receiver  132  and stored in the database  135  into SI′ data with a table for the SI standard, and sends the SI′ data to the multiplexer  140 . The PSI reconstructor  136  reconstructs the PSI data received from the PSI receiver  131  and stored in the database  135  into PSI′ data, and sends the PSI′ data to the multiplexer  140 . The multiplexer  140  multiplexes the SI′ and PSI′ data and the rest of the transport TS having the broadcast protocol extracted therefrom. Thus the broadcast protocol of the transport TS is converted from PSIP to SI. 
     Likewise, for SI-to-PSIP conversion, the PSIP reconstructor  137  and the PSI reconstructor  136  reconstruct the SI and PSI data stored in the database  135  into PSIP′ and PSI′ data, respectively. The PSIP′ and PSI′ data are then multiplexed at the multiplexer  140 . The SI-to-PSIP conversion is similar to the PSIP-to-SI conversion and will not be described in detail. 
     FIG  4  is a flow chart showing a process  400  of digital broadcast protocol conversion. At block  401 , a first transport stream of an ATSC broadcast standard or a second transport stream of a DVB broadcast standard is received to determine a protocol conversion pattern. When the protocol conversion pattern is a SI-to-PSIP conversion, process  400  proceeds to blocks  402 - 404 . At block  402 , first PSIP/PSI data from the first transport stream is extracted as a first broadcast protocol. At block  403 , the first PSIP/PSI data is reconstructed to a second table suitable for a second broadcast protocol of the DVB broadcast standard to generate second SI/PSI data. At block  404 , the second SI/PSI data and the first transport stream having the first PSIP/PSI extracted therefrom are multiplexed. When the protocol conversion pattern is PSIP-to-SI conversion, process  400  proceeds to blocks  405 - 407 . At block  405 , first SI/PSI data from the second transport stream is extracted as the first broadcast protocol. At block  406 , the first SI/PSI data is reconstructed to a first table suitable for the first broadcast protocol of the ATSC broadcast standard to generate second PSIP/PSI data. At block  407 , the second PSIP/PSI data and the second transport stream having the first SIIPSI data extracted therefrom are multiplexed. 
     Although broadcast protocol conversions between ATSC and DVB broadcast standards have been described in this embodiment, the present invention may also be applied to other broadcast protocol conversions between different broadcast standards, other than ATSC or DVB. 
     While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. 
     According to the present invention, the broadcast protocol of the transport stream may be converted between ATSC and DVB broadcast standards in real time, so that contents produced in a specific standard may be used in a system of a different standard. In addition, the contents stored in a storage unit may also be used in a broadcast system of a different standard.