APPARATUS AND METHOD FOR TRANSMITTING MOVING PICTURE EXPERTS GROUP (MPEG)-2 TRANSPORT STREAM (TS) BROADCASTING DATA
20170257468 · 2017-09-07
Inventors
Cpc classification
H03M13/1102
ELECTRICITY
H04N21/4345
ELECTRICITY
H04L67/565
ELECTRICITY
H03M13/09
ELECTRICITY
H04N21/2383
ELECTRICITY
H04N21/4382
ELECTRICITY
International classification
H03M13/09
ELECTRICITY
H04N21/434
ELECTRICITY
Abstract
An apparatus and method for transmitting moving picture experts group (MPEG)-2 transport stream (TS) broadcasting data for a broadcasting service based on a physical layer transmission standard defined in a Data over Cable Service Interface Specification (DOCSIS) 3.1. The apparatus includes a converter configured to receive an input of broadcasting data including a plurality of MPEG-2 TS packets and to convert the broadcasting data to a first file with a forward error correction (FEC) codeword structure, and an encoder configured to encode the first file.
Claims
1. A broadcasting data transmission apparatus comprising: a converter configured to receive an input of broadcasting data comprising a plurality of moving picture experts group (MPEG)-2 transport stream (TS) packets and to convert the broadcasting data to a first file with a forward error correction (FEC) codeword structure; and an encoder configured to encode the first file.
2. The broadcasting data transmission apparatus of claim 1, wherein the FEC codeword structure comprises at least one of a CW header, an extended header, a payload, a Bose-Chaudhri-Hocquenghem (BCH) parity and a low-density parity-check (LDPC) parity.
3. The broadcasting data transmission apparatus of claim 1, wherein the converter is configured to remove a sync byte from at least one of the plurality of MPEG-2 TS packets included in the broadcasting data, to perform a cyclic redundancy check (CRC) operation and to form a payload of the first file.
4. The broadcasting data transmission apparatus of claim 1, wherein the converter is configured to generate a CW header of the first file so that the CW header includes at least one of a frame pointer field indicating a byte location of a first packet included in a payload of the first file among the plurality of MPEG-2 TS packets, a type field indicating a type of data of the first file, and a valid field indicating whether a value of the frame pointer field is valid.
5. The broadcasting data transmission apparatus of claim 1, wherein the converter is configured to generate an extended header of the first file so that the extended header includes a null packet deletion field indicating whether a null packet is deleted from the plurality of MPEG-2 TS packets, a timestamp field indicating whether a timestamp of a time at which each of the plurality of MPEG-2 TS packets is input is used, and a logical channel number field indicating a number of virtual channels that are logically distinguished.
6. The broadcasting data transmission apparatus of claim 1, wherein the encoder is configured to perform at least one of BCH encoding, LDPC encoding and bit interleaving on the first file.
7. The broadcasting data transmission apparatus of claim 1, further comprising: a transmitter configured to transmit the first file using at least one virtual channel.
8. A broadcasting data transmission method comprising: receiving an input of broadcasting data comprising a plurality of moving picture experts group (MPEG)-2 transport stream (TS) packets and converting the broadcasting data to a first file with a forward error correction (FEC) codeword structure; and encoding the first file.
9. The broadcasting data transmission method of claim 8, wherein the FEC codeword structure comprises at least one of a CW header, an extended header, a payload, a Bose-Chaudhri-Hocquenghem (BCH) parity and a low-density parity-check (LDPC) parity.
10. The broadcasting data transmission method of claim 8, wherein the converting comprises removing a sync byte from at least one of the plurality of MPEG-2 TS packets included in the broadcasting data, performing a cyclic redundancy check (CRC) operation, and forming a payload of the first file.
11. The broadcasting data transmission method of claim 8, wherein the converting comprises generating a CW header of the first file so that the CW header includes at least one of a frame pointer field indicating a byte location of a first packet included in a payload of the first file among the plurality of MPEG-2 TS packets, a type field indicating a type of data of the first file, and a valid field indicating whether a value of the frame pointer field is valid.
12. The broadcasting data transmission method of claim 8, wherein the converting comprises generating an extended header of the first file so that the extended header includes a null packet deletion field indicating whether a null packet is deleted from the plurality of MPEG-2 TS packets, a timestamp field indicating whether a timestamp of a time at which each of the plurality of MPEG-2 TS packets is input is used, and a logical channel number field indicating a number of virtual channels that are logically distinguished.
13. The broadcasting data transmission method of claim 8, wherein the encoding comprises performing at least one of BCH encoding, LDPC encoding and bit interleaving on the first file.
14. A method of converting a first packet among a plurality of moving picture experts group (MPEG)-2 transport stream (TS) packets included in input broadcasting data to a forward error correction (FEC) codeword structure, the method comprising: removing a sync byte from the first packet, performing a cyclic redundancy check (CRC) operation and forming a payload; generating a CW header comprising a byte location of the first packet included in the payload; and performing FEC encoding on the payload and the CW header.
15. The method of claim 14, further comprising: generating an extended header comprising information about whether a null packet is deleted from the first packet and whether a timestamp of a time at which the first packet is input is used.
16. The method of claim 15, wherein the performing comprises: generating a Bose-Chaudhri-Hocquenghem (BCH) parity by performing BCH encoding on a data block comprising the payload, the CW header and the extended header; and generating a low-density parity-check (LDPC) parity by performing LDPC encoding on the data block.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] These and/or other aspects, features, and advantages of the invention will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which:
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
DETAILED DESCRIPTION
[0036] Particular structural or functional descriptions of embodiments according to the concept of the present disclosure disclosed in the present disclosure are merely intended for the purpose of describing embodiments according to the concept of the present disclosure and the embodiments according to the concept of the present disclosure may be implemented in various forms and should not be construed as being limited to those described in the present disclosure.
[0037] Though embodiments according to the concept of the present disclosure may be variously modified and be several embodiments, specific embodiments will be shown in drawings and be explained in detail. However, the embodiments are not meant to be limited, but it is intended that various modifications, equivalents, and alternatives are also covered within the scope of the claims.
[0038] Although terms of “first,” “second,” etc. are used to explain various components, the components are not limited to such terms. These terms are used only to distinguish one component from another component. For example, a first component may be referred to as a second component, or similarly, the second component may be referred to as the first component within the scope of the right according to the concept of the present disclosure.
[0039] When it is mentioned that one component is “connected” or “accessed” to another component, it may be understood that the one component is directly connected or accessed to another component or that still other component is interposed between the two components. Also, when it is mentioned that one component is “directly connected” or “directly accessed” to another component, it may be understood that no component is interposed therebetween. Expressions used to describe the relationship between components should be interpreted in a like fashion, for example, “between” versus “directly between,” or “adjacent to” versus “directly adjacent to.”
[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components or a combination thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0041] Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments belong. It will be further understood that terms, such as those defined in commonly-used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0042] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The scope of the right, however, should not be construed as limited to the embodiments set forth herein. Regarding the reference numerals assigned to the elements in the drawings, it should be noted that the same elements will be designated by the same reference numerals.
[0043]
[0044] Referring to
[0045] A frame pointer field 123 of a codeword header 111 indicates a location of a first byte of a new MAC frame that starts in the payload 112. In the present disclosure, a codeword header may be referred to as a “CW header.” A data block of 1,779 bytes obtained by combining the CW header 111 and the payload 112 for FEC encoding may generate a Bose-Chaudhri-Hocquenghem (BCH) parity 113 of 21 bytes and a low-density parity-check (LDPC) parity 114 of 225 bytes through BCH encoding and LDPC encoding, and accordingly a final FEC codeword 110 may be formed. Information included in fields in the CW header 111 may be defined as shown in Table 1 below.
TABLE-US-00001 TABLE 1 Field name Length Value Valid 121 1 bit ‘0’ = Value of a frame pointer field is not valid ‘1’ = Value of a frame pointer field is valid Reserved 122 .sup. 4 bits “0000” = Reserved for future use Frame 11 bits.sup. Indicates a location of a first byte of a Pointer 123 DOCSIS MAC frame starting in a payload
[0046] As shown in
[0047]
[0048] The broadcasting data transmission apparatus 200 may be configured to transmit MPEG-2 TS broadcasting data for a broadcasting service based on a physical layer transmission standard defined in the DOCSIS 3.1. Referring to
[0049] The converter 210 may receive an input of broadcasting data including a plurality of MPEG-2 TS packets and may convert the broadcasting data to a first file with an FEC codeword structure. The FEC codeword structure may include at least one of a CW header, an extended header, a payload, a BCH parity and an LDPC parity.
[0050] The converter 210 may remove a sync byte from at least one of the plurality of MPEG-2 TS packets included in the broadcasting data, may perform a cyclic redundancy check (CRC) operation, and may form a payload of the first file. For example, an 8-bit checksum generated by performing a CRC-8 operation on 187 bytes remaining after a sync byte with a value of “0x47” is removed from the at least one packet may be added to each of the at least one packet, and the at least one packet may be sequentially mapped to the payload.
[0051] The converter 210 may generate a CW header of the first file so that the CW header may include at least one of a frame pointer field, a type field and a valid field. The frame pointer field may indicate a byte location of a first packet included in the payload of the first file among the plurality of MPEG-2 TS packets. The type field may indicate a type of data of the first file, and the valid field may indicate whether a value of the frame pointer field is valid.
[0052] Also, the converter 210 may generate an extended header of the first file so that the extended header may include a null packet deletion field, a timestamp field and a logical channel number field. The null packet deletion field may indicate whether a null packet is deleted from the plurality of MPEG-2 TS packets. The timestamp field may indicate whether a timestamp of a time at which each of the plurality of MPEG-2 TS packets is input is used. The logical channel number field may indicate a number of virtual channels that are logically distinguished.
[0053] The encoder 220 may encode the first file. The encoder 220 may perform at least one of BCH encoding, LDPC encoding and bit interleaving on the first file.
[0054] The transmitter 230 may transmit the first file using at least one virtual channel.
[0055] The broadcasting data transmission apparatus 200 may effectively transmit MPEG-2 TS broadcasting data based on a physical layer standard defined in the DOCSIS 3.1. Unlike existing DOCSIS, a physical layer input interface format is defined as a DOCSIS MAC frame in the DOCSIS 3.1, and accordingly communication data may be efficiently transmitted based on the physical layer standard. However, there is a limitation on a transmission of an MPEG-2 TS that is broadcasting data. The broadcasting data transmission apparatus 200 may compensate for the above limitation and may enable the MPEG-2 TS to be directly transmitted in a physical layer of the DOCSIS 3.1. Thus, it is possible to enhance a broadcasting data transmission efficiency.
[0056]
[0057] An input MPEG-2 TS 300 may include a row of MPEG-2 TS packets, for example, MPEG-2 TS packets 301, 302 and 303, with 188 bytes. An 8-bit checksum generated by performing a CRC-8 operation on 187 bytes remaining after a sync byte with a value of “0x47” is removed from each of the MPEG-2 TS packets may be added to a rear portion of each of MPEG-2 TS packets 311, 312 and 313. The MPEG-2 TS packets 311, 312 and 313 may be sequentially located in a payload 323 of an FEC codeword 320. Also, a portion of the MPEG-2 TS packets may be mapped to a payload of a next FEC codeword. A BCH parity 324 and an LDPC parity 325 of
[0058] A frame pointer field 333 of a CW header 321 may indicate a location of a first byte of a first MPEG-2 TS packet starting in a payload, and may correspond to a location of a CRC checksum of a previous packet. A reserved field of the CW header 321 may be redefined and used as a type field 332 to identify data to be transmitted. For example, “0001” of the type field 332 may indicate that an MPEG-2 TS is transmitted.
[0059] An extended header 322 of 2 bytes may be generated by extending from a rear portion of the CW header 321. Due to the extended header 322, a length of the payload 323 may be 1,775 bytes that is reduced by 2 bytes. The CW header 321 and the extended header 322 generated as described above may be defined as shown in Table 2 below.
TABLE-US-00002 TABLE 2 Classification Field name Length Value CW Valid 331 1 bit ‘0’ = Value of a frame pointer header 321 field is not valid (2 bytes) ‘1’ = Value of a frame pointer field is valid Type 332 .sup. 4 bits “0000” = Transmission of DOCSIS MAC frame “0001” = Transmission of MPEG-2 TS “0010”~“1111” = Reserved for future use Frame 11 bits.sup. Indicates a location of a first pointer 333 byte of a DOCSIS MAC frame starting in a payload Extended Null packet 1 bit ‘0’ = Null packet deletion is header 322 deletion 334 not used (2 bytes) ‘1’ = Null packet deletion is used Timestamp 1 bit ‘0’ = Timestamp is not used 335 ‘1’ = Timestamp is used Reserved .sup. 2 bits Reserved for future use 336 Logical 12 bits.sup. Indicates channels that are channel logically distinguished from number 337 each other (the channels are the same as a virtual channel used in digital broadcasting)
[0060] A null packet deletion field 334 defined in the extended header 322 may indicate whether a null TS packet is removed from input MPEG-2 TS packets. A timestamp field 335 defined in the extended header 322 may indicate whether information on a time at which an MPEG-2 TS packet is input is added to a packet. The FEC codeword 320 may indicate that a null packet is not deleted and a timestamp is not added, because both the null packet deletion field 334 and the timestamp field 335 have a value of zero. An FEC codeword 420 of
[0061] Referring to
[0062] Generally, an MPEG-2 TS may include a meaningless null packet to maintain a transmission rate over a predetermined level. To increase an efficiency for transmission, a meaningless packet may not be transmitted. However, since a predetermined transmission rate needs to be maintained in the MPEG-2 TS, a null packet may be included in the MPEG-2 TS and may be transmitted. For example, when a null packet is deleted in a transmitter, a receiver may need to generate the deleted packet again. Accordingly, information about whether a null packet is deleted may be provided based on the null packet deletion field 334 and a null packet deletion field 435 of an extended header 422. Also, an “N” field with a length of 1 byte may be added to a rear portion of each of the MPEG-2 TS packets 412 and 413 that are additionally transmitted, and may indicate a number of null packets deleted from a front portion of a corresponding packet.
[0063] In addition, since a predetermined transmission rate of an MPEG-2 TS needs to be maintained, a predetermined time interval between packets included in the MPEG-2 TS may need to be maintained. Since the MPEG-2 TS includes packets to transfer information associated with time for playback of video and audio, it may be difficult to play back video and audio when jitter occurs in a transmission time of packets during transmission. To solve the above problem, the timestamp field 335 and a timestamp field 434 of the extended header 422 may be used to notify whether a timestamp of each packet is used, and a “T” field with a length of 3 bytes may be added to a rear portion of each of the MPEG-2 TS packets 412 and 413 and may indicate a time at which a corresponding packet is input.
[0064] Null packet deletion and use of a timestamp may be selectively performed in examples of
[0065] Logical channel number fields 337 and 437 included in the extended headers 322 and 422, respectively, may indicate a number of channels that are logically distinguished, and the logical channels may be understood to be the same as a virtual channel used in digital broadcasting. Since the DOCSIS 3.1 is a standard based on transmission of a large quantity of data using a broad channel, it is possible to provide a large number of video services in a single broad channel. In an existing transmission system using 6 megahertz (MHz) as a single broadcasting channel, about five or six video services may be multiplexed and provided by distinguishing virtual channels. Since the multiplexing may be performed in an MPEG-2 TS layer, there is no relevance to a physical layer of transmission. In the present disclosure, services may be classified in a physical layer so that a large number of video services may be distinguished within a single broad channel, and accordingly the logical channel number fields 337 and 437 may be defined.
[0066] A BCH parity 424 and an LDPC parity 425 of
[0067]
[0068] Referring to
[0069] When a timestamp is used, a timestamp for the input TS packet 510 may be inserted in operation 520, a “T” field 531 of 3 bytes may be added to a rear portion of a TS packet 530, and may indicate a time at which a corresponding packet is input.
[0070]
[0071] Referring to
[0072] The input processing block 610 may include an input interface sub-block 611, a CW payload forming sub-block 612 and a CW header generating sub-block 613. The input processing block 610 may be used to process a codeword conversion process of a MAC frame described above with reference to
[0073]
[0074] In the physical layer transmission structure of
[0075] Also, in the physical layer transmission structure of
[0076] When the FEC encoding is performed, the DOCSIS MAC frame may be processed by a QAM constellation mapping block 730, a time-frequency interleaving block 740, and an OFDM signal generating block 750, and the processed DOCSIS MAC frame may be transmitted, similarly to the basic physical layer downstream transmission structure of
[0077]
[0078] In
[0079]
[0080] The broadcasting data transmission method may be performed by a broadcasting data transmission apparatus to transmit MPEG-2 TS broadcasting data for a broadcasting service based on a physical layer transmission standard defined in the DOCSIS 3.1.
[0081] In operation 910, a converter of the broadcasting data transmission apparatus may receive an input of broadcasting data including a plurality of MPEG-2 TS packets and may convert the broadcasting data to a first file with an FEC codeword structure. The FEC codeword structure may include at least one of a CW header, an extended header, a payload, a BCH parity and an LDPC parity.
[0082] In operation 910, the converter may remove a sync byte from at least one of the plurality of MPEG-2 TS packets included in the broadcasting data, may perform a cyclic redundancy check (CRC) operation, and may form a payload of the first file. For example, an 8-bit checksum generated by performing a CRC-8 operation on 187 bytes remaining after a sync byte with a value of “0x47” is removed from the at least one packet may be added to each of the at least one packet, and the at least one packet may be sequentially mapped to the payload.
[0083] In operation 910, the converter may generate a CW header of the first file so that the CW header may include at least one of a frame pointer field, a type field and a valid field. The frame pointer field may indicate a byte location of a first packet included in the payload of the first file among the plurality of MPEG-2 TS packets. The type field may indicate a type of data of the first file, and the valid field may indicate whether a value of the frame pointer field is valid. Also, the converter may generate an extended header of the first file so that the extended header may include a null packet deletion field, a timestamp field and a logical channel number field. The null packet deletion field may indicate whether a null packet is deleted from the plurality of MPEG-2 TS packets. The timestamp field may indicate whether a timestamp of a time at which each of the plurality of MPEG-2 TS packets is input is used. The logical channel number field may indicate a number of virtual channels that are logically distinguished.
[0084] In operation 920, an encoder of the broadcasting data transmission apparatus may encode the first file obtained in operation 910. In operation 920, the encoder may perform at least one of BCH encoding, LDPC encoding and bit interleaving on the first file.
[0085] When operation 920 is performed, a transmitter of the broadcasting data transmission apparatus may transmit the first file using at least one virtual channel.
[0086] The units and/or modules described herein may be implemented using hardware components and software components. For example, the hardware components may include microphones, amplifiers, band pass filters, audio to digital convertors, and processing devices. A processing device may be implemented using one or more hardware device configured to carry out and/or execute program code by performing arithmetical, logical, and input/output operations. The processing device(s) may include a processor, a controller and an arithmetic logic unit, a digital signal processor, a microcomputer, a field programmable gate array, a programmable logic unit, a microprocessor or any other device capable of responding to and executing instructions in a defined manner. The processing device may run an operating system (OS) and one or more software applications that run on the OS. The processing device also may access, store, manipulate, process, and create data in response to execution of the software. For purpose of simplicity, the description of a processing device is used as singular; however, one skilled in the art will appreciated that a processing device may include multiple processing elements and multiple types of processing elements. For example, a processing device may include multiple processors or a processor and a controller. In addition, different processing configurations are possible, such as parallel processors.
[0087] The software may include a computer program, a piece of code, an instruction, or some combination thereof, to independently or collectively instruct and/or configure the processing device to operate as desired, thereby transforming the processing device into a special purpose processor. Software and data may be embodied permanently or temporarily in any type of machine, component, physical or virtual equipment, computer storage medium or device, or in a propagated signal wave capable of providing instructions or data to or being interpreted by the processing device. The software also may be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. The software and data may be stored by one or more non-transitory computer readable recording mediums.
[0088] The methods according to the above-described embodiments may be recorded in non-transitory computer-readable media including program instructions to implement various operations of the above-described embodiments. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The program instructions recorded on the media may be those specially designed and constructed for the purposes of embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of non-transitory computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM discs, DVDs, and/or Blue-ray discs; magneto-optical media such as optical discs; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory (e.g., USB flash drives, memory cards, memory sticks, etc.), and the like. Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The above-described devices may be configured to act as one or more software modules in order to perform the operations of the above-described embodiments, or vice versa.
[0089] A number of embodiments have been described above. Nevertheless, it should be understood that various modifications may be made to these embodiments. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claim.