EP1820340A1

EP1820340A1 - Apparatus for splicing of terrestrial dmb signal

Info

Publication number: EP1820340A1
Application number: EP05856392A
Authority: EP
Inventors: Jin-Hwan 110-403 Hanul Apt. Sinseong-dong LEE; Yong-Hoon 304 Yerim Villa 122-2 LEE; Byung-Jun 104-1506 Dungji Apt. BAE; Young-Kwon 133-101 Hanbit Apt. Eoeun-dong HAHM
Original assignee: Electronics and Telecommunications Research Institute ETRI
Current assignee: Electronics and Telecommunications Research Institute ETRI
Priority date: 2004-12-10
Filing date: 2005-09-28
Publication date: 2007-08-22
Also published as: CN101116334B; KR20060065361A; KR100789365B1; EP1820340A4; WO2006080660A1; CN101116334A

Abstract

Provided is an apparatus for splicing a terrestrial DMB signal. The apparatus includes: a first media data analyzing and correcting unit for analyzing a first media data which is a current broadcasted MPEG transport stream (TS), extracting first splicing information required for splicing, and correcting the first media data to be proper to a MPEG system standard after splicing; a second media data analyzing and correcting unit for analyzing a second media data, which is a MPEG TS to be inserted through splicing, extracting second splicing information required for splicing, and correcting the second media data to be proper to a MPEG system standard after splicing; and a stream multiplexing unit for selecting a stream of the corrected second media data to be inserted through splicing at a time of splicing while transmitting streams of the corrected first media data, and outputting the selected stream.

Description

APPARATUS FOR SPLICING OF TERRESTRIAL DMB SIGNAL

Technical Field

[1] The present invention relates to an apparatus for splicing a terrestrial DMB video signal, and more particular to an apparatus for splicing a terrestrial DMB video signal to constantly provide an uninterrupted broadcasting service although a program is inserted and transmitted while another program is transmitting in a terrestrial DMB transmitting system.

[2]

Background Art

[3] An Eureka- 147 based digital audio broadcasting (DAB) transmitting system is developed to process and transmit audio data or small amount of data because an object of the Eureka- 147 based DAB transmitting system is digitalization of analog audio broadcasting. However, a new standard and technology for a terrestrial digital multimedia broadcasting (DMB) standard is developed in Korea and European Telecommunications Standards Institute (ETSI) in order to use the Eureka- 147 based DAB transmitting system to provide a moving image multimedia service.

[4] Fig. 1 is a block diagram illustrating the conceptual architecture of the DMB video multiplexer.

[5] The conceptual architecture of the DMB video multiplexer is shown in Fig.1 includes an IOD generator 101, an OD/BIFS generator 102, an MPEG-4 video encoder 103, an MPEG-4 audio encoder 104, a SL (Sync layer) packetizer 106, an additional data block 105, a section generator 107, a PES (Packetizer Elementary Stream) packetizer 108, a TS (transport stream) multiplexer 109 and an outer-encoder 110. That is stated in the ETSI TS (Technical Specification) 102 428 as follows.

[6] The IOD generator 101 creates IODs that comply with the ISO/IEC 14496-1. The

OD/BIFS generator 102 creates OD/BIFS streams that comply with the ISO/IEC 14496-1. The MPEG-4 video encoder 103 generates an encoded bitstream compliant with the ISO/IEC 14496-10. The MPEG-4 audio encoder 104 generates an encoded bitstream compliant with the ISO/IEC 14496-3. The additional data block 105 is selectively used only when auxiliary information is transported or synchronized interactive services are provided. The SL packetizer 106 generates a SL packet stream, compliant with ISO/IEC 14496-1. The section generator 107 creates sections compliant with ISO/IEC 13818-1 for the input IOD/OD/BIFS. The PES packetizer 108 generates a PES packet stream compliant with ISO/IEC 13818-1 for SL packet Stream. The TS multiplexer 109 combines the input sections and PES packet streams into a single MPEG-2 TS complying with ISO/IEC 13818-1. The outer-encoder 110 generates RS (Reed-Solomon) encodes for error correction to the packet in the MPEG- 2 TS multiplexed data stream and the RS encoded data stream is convolutional interleaved.

[7] The multiplexed (and outer-coded) stream is transmitted by the Main Service

Channel (MSC) stream mode data channel of Eureka- 147 DAB defined in ETSI EN 300 401.

[8] A terrestrial DMB transmitting system generates an ensemble signal of the Eureka-

174 based DAB standard and transmits the generated ensemble signal.

[9] The general digital broadcasting system including the terrestrial DMB transmitting system may not provide an uninterrupted broadcasting service when a current broadcasting digital signal inputted from a first broadcasting signal source is spliced with a new broadcasting digital signal inputted from a second broadcasting signal source while transmitting the current broadcasting digital signal from the first broadcasting source differently from a conventional analog broadcasting system.

[10] In order to prevent such an interruption program, the broadcasting digital signals from the first and the second broadcasting digital signal source are decoded to broadcasting analog signals, the broadcasting analog signals are spliced, the spliced broadcasting analog signal is encoded to a broadcasting digital signal again, and then the encoded digital signal is transmitted. Therefore, high-cost encoding equipment is required to encode and decode the digital broadcasting signals, and an image quality is degraded by the decoding and the encoding process.

[H]

Disclosure of Invention

Technical Problem

[12] It is, therefore, an object of the present invention to provide an apparatus for splicing a terrestrial DMB signal to provide an uninterrupted broadcasting service although other program is inserted and transmitted while a terrestrial DMB transmitting system is transmitting a predetermined program.

[13] It is another object of the present invention to provide an apparatus for splicing a terrestrial DMB signal to provide an uninterrupted broadcasting service when a commercial program is inserted and transmitted while a terrestrial DMB transmitting system is transmitting a predetermined program, the predetermined program is inserted and transmitted again while the terrestrial DMB transmitting system is transmitting the commercial program, a local broadcasting program is inserted and transmitted while the terrestrial DMB transmitting system is transmitting a central broadcasting program, or the central broadcasting program is inserted and transmitted while the terrestrial DMB transmitting system is transmitting the local broadcasting program. [14]

Technical Solution

[15] In accordance with one aspect of the present invention, there is provided an apparatus for splicing a terrestrial digital multimedia broadcasting (DMB) signal including: a first media data (not outer-encoded DMB video TS) analyzing and correcting unit for analyzing a first media data which is a current broadcasted MPEG transport stream (TS), extracting first splicing information required for splicing, and correcting the first media data to be proper to a MPEG system standard after splicing; a second media data analyzing and correcting unit for analyzing a second media data, which is a MPEG TS to be inserted through splicing, extracting second splicing information required for splicing, and correcting the second media data to be proper to a MPEG system standard after splicing; and a stream multiplexing unit for selecting a stream of the corrected second media data to be inserted through splicing at a time of splicing while transmitting streams of the corrected first media data, and outputting the selected stream.

[16]

Advantageous Effects

[17] An apparatus for splicing a terrestrial DMB signal according to the present invention provides an uninterrupted broadcasting service when a terrestrial DMB transmitting system inserts and transmits a local broadcasting program or a commercial program while re-transmitting a central broadcasting program.

[18] The apparatus for splicing a terrestrial DMB signal according to the present invention does not require expensive encoding equipments and prevents degradation of image quality since the apparatus according to the present invention dose not require to encode digital broadcasting signals to analog broadcasting signals for splicing and to decode the spliced analog broadcasting signal to the digital broadcasting signal for transmitting.

[19]

Brief Description of the Drawings

[20] The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:

[21] Fig. 1 is a block diagram illustrating the conceptual architecture of the DMB video multiplexer; and

[22] Fig. 2 is a block diagram showing an apparatus for splicing a terrestrial DMB signal in accordance with a preferred embodiment of the present invention. [23]

Best Mode for Carrying Out the Invention

[24] Other objects and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter.

[25] An apparatus for splicing a terrestrial DMB broadcasting signal according to the present invention splices a digital ensemble signal or a digital DMB signal in MPEG-2 TS layer in a terrestrial DMB transmitting system using an Eureka- 147 based DAB transmitting scheme.

[26] Fig. 2 is a block diagram showing an apparatus for splicing a terrestrial DMB signal in accordance with a preferred embodiment of the present invention.

[27] Referring to Fig. 2, the apparatus for splicing a terrestrial DMB signal according to the present embodiment includes ensemble data analyzing units 201, 211 for receiving ensemble data and analyzing the received ensemble data; outer-decoding units 202 and 212 for outer-decoding media data of a sub-channel in order to use the outer-decoded data for splicing in the inputted ensemble data frame; media data analyzing and correcting unit 203, 213 for analyzing outer-decoded MPEG-2 TS media data and correcting the outer-decoded MPEG-2 TS media data to be proper to MPEG-2 and MPEG-4 system standard after splicing; buffers 204, 214 for storing and reading media data; a stream multiplexing unit 205 for selecting one of a current transmitting stream or a new stream to be transmitted and outputting the selected stream; an outer- encoding unit 206 for outer-encoding the spliced media data; an ensemble data composing unit 207 for composing an ensemble data to be suitable to an Eureka- 147 standard and outputting the composed ensemble data; and a buffer 208 for temporally storing data required to compose the ensemble data.

[28] MPEG-2 TS media data or Eureka- 147 ensemble signal may be used as an input signal. According to the present invention, an input signal B is spliced and broadcasted while broadcasting an input signal A, where the input signal A denotes media data A or ensemble data A and the input signal B also denotes media data B or ensemble data B.

[29] The ensemble data analyzing unit 201 or 211 receives ensemble data, analyzes the ensemble data frame, isolates media data of a sub channel to be used for splicing, and outputs the isolated media data to the outer-decoding unit 202 or 212.

[30] The outer decoding unit 202 or 212 outer-decodes the isolated media data, and outputs outer-decoded media data to the corresponding media data analyzing and correcting unit 203 or 213. For outer-decoding, a convolution de-interleaver scheme or a reed Solomon decoding scheme may be used.

[31] The media data analyzing and correcting unit 203 or 213 receives media data from an external unit or the outer-decoding unit 202 or 212, analyzes the received media data, extracts predetermined information for splicing, and corrects the media data to be suitable to MPEG-2 and MPEG-4 system standard after splicing. That is, the media data analyzing and correcting unit 203 or 213 manages stream data not to be cut off in a payload unit at a splicing boundary portion, and corrects the media data to have a consistency in program identifier allocation per an elementary stream, time information PCR, OCR, DTS, CTS, and continuity counter between a previous transmitted stream and a new stream.

[32] Such an operation of the media data analyzing and correcting unit 203 or 213 will be described in detail hereinafter.

[33] The media data analyzing and correcting unit obtains program specific information

(PSI) by analyzing a program association table (PAT) and a program map table (PMT) in the inputted TS packet. The PSI includes PID composing information of each ESs such as BIFS, OD, video and audio. And, if the PSI of the inputted stream is different from PSI of current transmitting stream, the media data analyzing and correcting unit corrects the inputted stream to have a consistency. Also, the media data analyzing and correcting unit manages TS packets having a same PID according to a payload unit not to be cut off in a payload unit. The TS packets may be composed PAT, PMT, BIFS, OD, video ES and audio ES. That is, the media data analyzing and correcting unit 203 or 213 corrects TS packets by orderly selecting a TS packet having "1" as a playload_unit_start_indicator from the TS packets and stores the corrected TS packets in a buffer or reads the TS packets by orderly selecting a TS packet having "1" as a playload_unit_start_indicator from the TS packets and corrects the read TS packets.

[34] After splicing the media data, the media data analyzing and correcting unit corrects the spliced media data to have a consistency between a continuity_counter value of previous transmitted stream and the same of current transmitting stream. That is, the media data analyzing and correcting unit corrects the continuity_counter value in the TS packets having a same PID to be increased from 0 to 15 repeatedly.

[35] The media data analyzing and correcting unit analyzes an adaptation_field, and corrects the adaptation_filed to have a consistency when there is a valid program clock reference (PCR). Also, there is information about a time of splicing, the splicing is performed using a splice_countdown value. The splice_countdown value denotes the number of TS packets having the same PID remained until the splicing is performed. The splicing is performed on TS packets having a same PID right after a TS packet having "0" as the splice_countdown a value.

[36] The media data analyzing and correcting unit corrects parameter values in a SL packet header to have a consistency between a previous transmitted stream and a current transmitting stream. The parameter values in the SL packet header may be an OCR, a DTS and a CTS.

[37] The time of splicing may be decided to use a splicing time information in the adaptation_field or a predetermined method set by broadcasting service providers or broadcasting equipments. After deciding the time of splicing, the media data analyzing and correcting unit manages stream data not to be cur off in a payload unit at a boundary portion around the time of splicing and manages the buffer not to be overflowed.

[38] The stream multiplexing unit 205 substitutes a previous transmitted stream with a new stream inputted from other stream source and outputs the substituted stream by considering the above described conditions. In case of media data A or ensemble data A, a stream stored in the buffer 204 is corrected to be proper to MPEG-2 and MPEG-4 system standards through the media data analyzing and correcting unit 203. In order to use a new substituted stream in the stream multiplexing unit 205 while the corrected media data is used as the input data in the stream multiplexing unit 205, stream stored in the buffer 214 is corrected to be proper to MPEG-2 and MPEG-4 system standard through the media data analyzing and correcting unit 213, and the corrected media data is used as input data in the stream multiplexing unit 205. Right after splicing, the video stream must be transmitted from an I screen.

[39] Accordingly, the I screen of the stream must be stored in the buffer 214 at first before using the steam for broadcasting, and all previous streams are eliminated after starting to store new I screen in the buffer 214. When data is stored in the buffer 204, a Null packet is eliminated and then the data is stored. Also, if an amount data stored in the buffer 204 is insufficient, a Null packet is generated and outputted to an external device or the outer-encoding unit 206.

[40] The outer-encoding unit 206 receives the spliced media data from the stream multiplexing unit 205, performs the outer-encoding on the spliced media data and outputs the outer-encoded data to the ensemble data composing unit 207.

[41] The ensemble data composing unit 207 receives the spliced media data from the outer-encoding unit 206, composing ensemble data to be suitable to the Eureka- 147 standard and outputs the ensemble data. Also, the ensemble data composing unit 207 receives data of other sub channel and fast information channel (FIC) information excepting the spliced media data from the ensemble data analyzing unit 201 or 211, and composing ensemble data with the media data from the outer-encoding unit 206.

[42] Meanwhile, the ensemble data composing unit 207 uses the buffer 208 storing FIC information and sub-channel data to compose the ensemble data. The ensemble data composing unit 207 manages the buffer not to be overflowed, and composes the ensemble frame to be suitable to the Eureka- 147 standard and outputs the ensemble frame. [43] The stream multiplexing unit 205 reads data stored in the buffers 204, 214 or generates Null packets when an amount of data stored in the buffer 208 is insufficient, and outputs one of the read data or the generated Null packet to the outer-encoding unit 206.

[44] The above described method according to the present invention can be embodied as a program and stored on a computer readable recording medium. The computer readable recording medium is any data storage device that can store data which can be thereafter read by the computer system. The computer readable recording medium includes a read-only memory (ROM), a random-access memory (RAM), a CD-ROM, a floppy disk, a hard disk and an optical magnetic disk.

[45] The present application contains subject matter related to Korean patent application

No. 2004-0104471, filed with the Korean Intellectual Property office on December 10, 2004, the entire contents of which is incorporated herein by reference.

[46] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

Claims

[1] An apparatus for splicing a terrestrial digital multimedia broadcasting (DMB) signal comprising: a first media data analyzing and correcting means for analyzing a first media data which is a current broadcasted MPEG transport stream (TS), extracting first splicing information required for splicing, and correcting the first media data to be proper to a MPEG system standard after splicing; a second media data analyzing and correcting means for analyzing a second media data, which is a MPEG TS to be inserted through splicing, extracting second splicing information required for splicing, and correcting the second media data to be proper to a MPEG system standard after splicing; and a stream multiplexing means for selecting a stream of the corrected second media data to be inserted through splicing at a time of splicing while transmitting streams of the corrected first media data, and outputting the selected stream.

[2] The apparatus as recited in claim 1, further comprising a first ensemble data analyzing means for analyzing a first ensemble data, isolating media data of a sub-channel, and outputting the isolated media data to the first media data analyzing and correcting means.

[3] The apparatus as recited in claim 2, further comprising a first outer-decoding means for performing an outer-decoding on a media data of a sub-channel to be used for splicing in a frame of the first ensemble data.

[4] The apparatus as recited in claim 1, further comprising a second ensemble data analyzing means for analyzing a second ensemble data, isolating media data of a sub-channel to be used for splicing, and outputting the isolated media data to the second media data analyzing and correcting means.

[5] The apparatus as recited in claim 4, further comprising: an outer-encoding means for performing an outer-encoding on media data outputted from the stream multiplexing means; an ensemble data composing means for re-composing ensemble data to be proper to a DMB broadcasting standard using the analyzing results of the first ensemble data analyzing means and the second ensemble data analyzing means; and a storing means for storing data required for composing the ensemble data.

[6] The apparatus as recited in claim 4, further comprising a second outer-decoding means for performing an outer-decoding on media data of a sub-channel to be used for splicing in a frame of the second ensemble data.

[7] The apparatus as recited in claim 6, further comprising: an outer-encoding means for performing an outer-encoding on media data outputted from the stream multiplexing means; an ensemble data composing means for recomposing ensemble data to be proper to a DMB broadcasting standard using the analyzing results of the first ensemble data analyzing means and the second ensemble data analyzing means; and a storing means for storing data required for composing the ensemble data.

[8] The apparatus as recited in claim 4, wherein the first media data analyzing and correcting means and the second media analyzing and correcting means obtains program specific information (PSI) by analyzing a program allocation table (PAT) and a program map table (PMT) of inputted media data, and corrects the PSI of the inputted media data to be identical to a PSI of a current broadcasted media data.

[9] The apparatus as recited in claim 4, wherein the first media data analyzing and correcting means and the second media analyzing and correcting means manages packets of media data having a same program identifier (PID) according to a payload unit, and corrects parameter values to maintain a consistency of the parameter values compared to parameter values of previous transmitted media data after splicing.

[10] The apparatus as recited in claim 9, wherein the parameters include time information and a continuity_counter.

[11] The apparatus as recited in claim 4, wherein the first media data analyzing and correcting means and the second media analyzing and correcting means use splicing time information in the media data or a predetermined method set by broadcasting service providers or broadcasting systems to decide a time of splicing.

[12] The apparatus as recited in claim 4, wherein the first media data analyzing and correcting means and the second media analyzing and correcting means store and manage the media data in an additional buffer, store the media data in the buffer after eliminating a Null packet, and if an amount of data stored in the buffer is insufficient when the media data is read from the buffer, a Null packet is generated and used.