JP6126676B1 - Private section packet structure, null packet structure and receiving modem - Google Patents

Abstract

An apparatus and method for generating a null packet including additional information in a video coding system are provided. In a video coding system, a private section 450, a TID field for identifying the type of the table section, an SSI field that defines the format of the table section, and whether the format of the table section conforms to the format of the private section A PRI field that represents the RES field for the table section to maintain the size of the private section data, a private data field that contains the data or information that is to be attached to the private section, and the data contained in the private data field or A TIE field and a private data field for classifying information types and a PSL field representing the data size of the TIE field are included. [Selection] Figure 4b

Description

  The present invention relates to an apparatus and method for transmitting additional information using a Null Packet in an MPEG-2 system.

  The contents described in this specification merely provide background information for this embodiment and do not constitute prior art.

  In the MPEG-2 system, a video signal and an audio signal are received by a video encoder and an audio encoder, and then compressed with a video elementary stream (ES) and an audio elementary stream according to a preset algorithm. The basic stream is decomposed into a plurality of PES (Packetized Elementary Stream) payloads by packetizing means, and PES headers are added before each payload to form a group of PES packets.

  By the multiplexer, each PES packet becomes a 188-byte TS (Transport Stream) packet, and each TS packet includes a 4-byte TS packet header and a 184-byte TS payload. However, a null packet is added between TS packets in order to adjust the transmission rate appropriate for the standard. The null packet simply has meaningless data as a packet inserted to match the transmission rate. Each null packet also includes a 4-byte TS packet header and a 184-byte payload. TS packets and null packets are distinguished from the TS packet header. The TS packet classified in this way is received by the receiving end, and after confirming that it is a TS packet, it is decoded by the decoder (Decoder), and the null packet is removed after being received by the receiving end. The

FIG. 1a is a diagram illustrating a configuration of a conventional null packet, and FIG. 1b is a diagram illustrating a configuration of a conventional private section.
As shown in FIG. 1a, the conventional null packet (110) includes a TS packet header (120) and a payload (130).
The TS packet header (120) includes a synchronization byte (121), TI (122), PI (123), TP (124), PID (125), SC (126), AF (127), and CC (128).

  The synchronization byte (synchronization byte, 121) is a fixed 8-bit sequence having the value “01000111” (0 × 47). The sequence is used to detect alerts between packets from systems that do not have other means of signaling the packets.

  TI (Transport Error Indicator) (122) confirms the field value of the transmission error indicator, and if the value is not 0, the corresponding TS packet cannot confirm the position and size. This indicates that the above bit error has been inserted.

  PI (Payload_Unit_Start_Indicator, payload unit start indicator) (123) indicates that the private section is started with a TS packet. Since no meaningful data is stored in the payload in the null packet, the PI field value has 0.

  A TP (Transport_Priority, transmission priority indicator) (124) makes it possible to distinguish high and low priority packets among packets having the same PID (packet identifier). A null packet has a TP field value of zero.

  The PID (Packet Identifier) (125) identifies the data source of the TS packet. The PID field is used by the decoder to extract the necessary TS packets. At this time, the null packet has a 0x1fff value as the PID field value. Thereby, a null packet and a TS packet can be distinguished.

SC (Transport Scrambling Control) (126) signals whether scramble is applied and what kind of scramble is applied. Here, scramble means information for encrypting and controlling an arbitrary approach. The SC field value is 0 in a null packet.
AF (Adaptation_Field_Control) (127) displays whether an adaptation field and / or payload is present in the TS packet. Since a null packet also has a payload, it has an AF field value of 1.

  CC (Countinuity Counter) (128) is the sequence number of the TS packet. The CC field value is incremented by 1 for each TS packet having the same PID. However, it is not defined for null packets.

  The payload means a part filled with broadcast data to be transmitted. The payload of the TS packet may include a private section having data recorded by the user for transmission. However, since the null packet is used only for the purpose of simply matching the transmission rate between the TS packets, the payload (130) of the null packet is filled with data having no meaning of 0xff.

  As shown in FIG. 1b, the conventional private section (140) includes TID (141), SSI (143), PRI (145), PSL (147) and private data bytes (149). TID (Table_Identifier) (141) indicates a value indicating that the section belongs to a private table.

  In SSI (Section_Syntax_Indicator) (143), when the SSI field value is 0, the private data byte (149) field follows the PSL (Private Section Length) (147) field. It shows that.

  PRI (Private Indicator) (145) indicates whether the table format conforms to the private section format. PSL (Private Section Length) (147) indicates the overall size of data transmitted from the next of the PSL field.

  The private data byte (149) is an area that can be defined and used by the user, and data to be transmitted can be recorded in the area.

  This embodiment is to provide an apparatus and a method for generating a null packet including additional information in an MPEG (Moving Pictures Exports Group) -2 system.

  According to one aspect of the present embodiment, a TID (Table Identification) field for identifying the type of a table section (Table Section) in a private section packet structure in a video coding system (Video Coding System). Field), an SSI (Section Syntax Indicator) field that defines the table section format, a PRI (Private Indicator) field that indicates whether the table section format conforms to the private section format, and the table section is the data of the private section. A RES (Reserved) field for maintaining the size, a private data (Data) field including data or information to be attached to the private section, and a type of data or information included in the private data field Provided is a packet structure of a private section including a TIE (Table Identification Extension) field, a private data field, and a PSL (Private Section Length) field indicating a data size of the TIE field.

  According to another aspect of the present embodiment, in a method for generating a null packet in a video coding system, a data packet embodied in a TS (Transport Stream) packet form is selected. TS packet header (Header) for judging whether to include data of contents, payload (Payload) including private section (Private Section) including data or information to be attached, and between the TS packet header and the payload A null packet packet structure including a PF (Pointer Field) for indicating that new data starts after the TS packet header is provided.

  In addition, according to another aspect of the present embodiment, AC data, TMCC data, and applications received from a video coding system transmitter are periodically monitored in a receiving modem of a video coding system receiver. A private section generation unit for generating a private section to which additional information including any one of the state information registers of the chips that require the data is attached, and a null packet including the private section generated by the private section generation unit. There is provided a receiving modem including a null packet generator for generating.

  As described above, according to this embodiment, AC (Auxiliary Channel) data, TMCC (Transmission and Multiplexing Configuration Control) data, and additional information such as chip status information are included in a null packet and transmitted together. be able to. This eliminates the need to additionally design each additional information buffer or the like necessary for transmitting such additional information by an application such as a decoder. Further, since the additional information is transmitted together with the null packet, there is no need for a separate path (Path) for transmitting the additional information. This simplifies the software structure for processing additional information.

FIG. 1a shows the structure of a conventional null packet. FIG. 1b shows the configuration of a conventional private section. FIG. 2a shows a conventional transmission stream transmission system. FIG. 2b shows a transmission system for a transmission stream according to one embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of the receiving modem according to one embodiment of the present invention. FIG. 4a shows the structure of a null packet according to one embodiment of the present invention. FIG. 4b shows the configuration of a private section according to one embodiment of the present invention. FIG. 5 illustrates a method for including AC data in a plurality of private sections according to an embodiment of the present invention. FIG. 6a shows a system for transmitting chip status information between a conventional receiving modem and an application. FIG. 6b shows a system for transmitting chip status information between a receiving modem and an application according to one embodiment of the present invention. FIG. 7a shows a system in which a conventional receiving modem transmits TS packets and additional information in an application. FIG. 7b shows a system in which a receiving modem transmits a TS packet and additional information in an application according to an embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Reference numerals are added to components in each drawing, and the same components are denoted by the same reference numerals as much as possible even if they are displayed in other drawings. In the description of the present invention, when it is determined that a specific description of a related known configuration or function gives a reverse evaluation to the present invention, a detailed description thereof is omitted.

  In all the specifications, when a component “includes” or “comprises” a part, this does not exclude other components, but excludes other components unless specifically stated to the contrary. It is meant to further include. In addition, terms such as '...' and 'module' described in the specification mean a unit for processing at least one function or operation, which is hardware or software or a combination of hardware and software. Can be embodied.

  FIG. 2a illustrates a conventional transmission stream transmission system, and FIG. 2b illustrates a transmission stream transmission system according to an embodiment of the present invention.

  2a includes a transmitter (210) and a receiver (220), and the receiver (220) includes a receiving modem (230), modem software (240), and decoder (250). Including.

  The transmitter (210) uses a receiver (220) to transmit a stream including TS packets and null packets and AC (Auxiliary Channel) data or TMCC (Transmission and Multiplexing Configuration Control) data or a chip that requires periodic monitoring. Additional information of (Chip) state information is transmitted. The transmission stream and each additional information are transmitted by the receiver 220 in a separate process.

  The receiver (220) refers to a device that receives data transmitted by a transmitter and extracts and processes the received data.

  The receiving modem (230) serves to receive data transmitted by the transmitter. Each of the transmission stream and the additional information is separately received, and each of them is transmitted by the modem software (240).

  The modem software (240) serves to analyze each of the transmission stream and additional information received from the receiving modem and perform necessary processing according to each information. The transmission stream is transmitted to the decoder (250).

  The decoder 250 plays a role of decoding according to the transmission stream received from the modem software.

  In the conventional transmission stream transmission system in the MPEG-2 standard, when the receiver receives a null packet, since the null packet contains only meaningless data in the conventional transmission stream transmission system, the reception module receives the null packet. It can be removed or transmitted by modem software without removing null packets. If the null packet is not removed by the receiving module and is transmitted to the modem software, the modem software can also remove the null packet or transmit by the decoder without removing the null packet. When transmitting by the decoder without removing the null packet by the modem software, the decoder discards the null packet without using the null packet because there is no data to be decoded into the null packet.

  As shown in FIG. 2b, a transmission system for a transmission stream according to an embodiment of the present invention includes a transmitter and a receiver as in the conventional transmission system, and the receiver includes a receiving modem (260), modem software, and the like. Includes a decoder.

  The receiving modem 260 receives the TS packet and the additional information received from the transmitter by the transmission system of the transmission stream according to one embodiment of the present invention. After the reception, the modem software transmits a null packet in which additional information having additional information is included in the null packet without transmitting by the modem software. As a result, since the null packet is transmitted together with the additional information, a separate buffer for the additional information for transmitting the additional information by the modem software is not required. Also, as shown in FIG. 2a, in order to transmit each additional information by modem software, a path for each additional information is required. According to one embodiment of the present invention, both are included in a null packet. Since transmission is performed, a separate passage for additional information is not required, and the structure is simplified. This also has the same effect on chip status information. When the status information of the chip that needs to be periodically monitored is required by an application including a decoder or the like, the conventional transmission system transmits using a separate path for the status information of the chip. According to the embodiment, since a null packet is included and transmitted together, a separate path is not required.

  The reason for attaching the additional information to the null packet is as follows. First, when additional information such as AC, TMCC, and chip status information is transmitted along with the transmission stream, there is no method capable of distinguishing from damaged data received by the receiving modem. When the transmitter and the receiver communicate using the transmission stream, the receiver checks and grasps the synchronization byte of the header for the transmission stream. At this time, if the additional information is attached to the transmission stream, the header information can be changed, which may cause the packet not to be used by the receiver, and thus is difficult to attach to the transmission stream. Second, if additional information is transmitted in the form of TS packets, it is inappropriate because it may be mistaken for a different packet identifier (PID) existing inside the receiver (In-Band). On the other hand, since the null packet is not used separately from other packet information, the above-described problem is not included. Since the null packet is not used in the processing process, any change in the null packet does not cause a problem in the receiver, particularly the decoder. For this reason, even if the null packet defined in the MPEG-2 standard is changed according to the embodiment of the present invention, the null packet according to the embodiment of the present invention causes a problem in the MPEG-2 standard system. There is no fear.

FIG. 3 shows a configuration of a receiving modem according to one embodiment of the present invention.
As shown in FIG. 3, the receiving modem 260 according to an embodiment of the present invention includes a private section generator 310 and a null packet generator 320.

  The private section generation unit 310 serves to generate a private section including a register (Register) that stores received AC data, TMCC data, and chip state information. Since the data or information to be transmitted is transmitted in the private section, it is different from the MPEG-2 standard private section format.

  The null packet generator (320) generates a null packet including the private section generated by the private section generator. The null packet is different from the MPEG-2 standard null packet format because it includes a private section generated by one embodiment of the present invention.

  FIG. 4a shows the configuration of a null packet according to one embodiment of the present invention, and FIG. 4b shows the configuration of a private section according to one embodiment of the present invention.

As shown in FIG. 4a, a null packet (410) according to an embodiment of the present invention includes a TS packet header (420), a PF (430), and a payload (440).
TS packet header (420) includes synchronization byte (421), TI (422), PI (423), TP (424), PID (425), SC (426), AF (427) and CC (428) .

  As described above, since attaching the additional information to the null packet (410) causes no problem in the process, the null packet (410) has a conventional null packet format. It has the same format and has 4 bytes with the TS packet header of the conventional null packet. Each field value of the TS packet header of the null packet (410) is the same as that of the conventional null packet. However, since the private section is disclosed in the payload (440) of the null packet (410), the null packet (410) has 1 in the PI (423) field value. Thereby, the null packet (410) and the conventional null packet can be distinguished. In order to distinguish between the null packet (410) and the conventional null packet, a method of changing fields other than the PI field can be considered, but if other fields than the PI field are changed, the null packet (410) is changed. The receiving modem software or decoder cannot guarantee whether it works properly. Therefore, each null packet is divided by changing the PI field in the TS packet header of the null packet.

The null packet (410) includes a PF (Poiner_Field) (430). The PF (430) corresponds to a field that exists when a packet includes data in a section form after the PF. In the case of the conventional null packet, there is no PF field because it does not include data. However, since the null packet (410) has a private section in the payload (440) next, a PF field exists. The PF field value has 0x00. The PF field has 1 byte.
The payload (440) includes information to be attached to the null packet. The payload includes a personal section. The null packet (410) has the same size as the conventional null packet. The null packet (410) has 188 bytes, but the payload (440) of the null packet (410) has 183 bytes because it further includes a different PF field from the conventional null packet.

  As shown in FIG. 4b, a private section according to one embodiment of the present invention, (450) is TID (451), SSI (452), PRI (453), RES (454), PSL (455), TIE (456). ) And private data (457).

  TID (451) has 0xff as a TID field value. Thereby, the TID field value has 0xff as follows. When the PID field value of the TS packet header is 0x1fff, the modem software recognizes the null packet, removes it, or transmits it by the decoder or application without passing. However, since the null packet according to the present embodiment has a PI field value of 1 in the TS packet header, the modem software searches for such a null packet and passes it. However, there is a possibility that the data is not passed by the modem software and transmitted without being processed by a decoder or an application like a conventional null packet. At this time, it is normal that the decoder or application does not process the received null packet. However, since the null packet according to the present embodiment has a PI field value of 1 in the TS packet header, an attempt can be made to pass it by a decoder or an application. At this time, if the PF field value of the null packet is 0 and the TID field value that is the next field of the PF field is 0xff, the decoder or application does not process any more data. That is, even if the PI field value of the TS packet header of the null packet is set differently from that of the standard null packet, the PF field has 0x00 and the private section TID field has 0xff, so the decoder or application No problem occurs because it is not processed.

  SSI (452) and PRI (453) play the same role as the SSI and PRI fields of the conventional personal section. Since Private Data is added to SSI (452), it has 0 as a field value, and PRI (453) has 1 as a field value.

RES (Reserved) (454) currently has a field value of 3 as a field whose use was not defined.
PSL (455) represents the size of the data of the additional information attached to the TIE field as a field indicating the size of field data appearing next to the PSL field.

  TIE (Table_Identifier_extension) (456) is an identifier for distinguishing the type of data positioned next to the TIE field. Since the TIE is an agreement between the receiving modem and the modem software, any identifier can be used as long as the type of data can be distinguished. For example, by confirming the TIE, it is possible to confirm whether the data located next to the TIE field is AC data recognition, TMCC data, or chip status information.

  Since the payload of the null packet according to this embodiment has 183 bytes, the private section according to this embodiment must also have 183 bytes. At this time, looking at the size of each field data of the private section, the TID field has 1 byte, and the SSL field, PRI field, RES field, and PSL field have 2 bytes as a whole. The TIE field has 2 bytes. Thus, the Private Data field of the private section has 178 bytes.

  Private Data (457) is a field including additional information to be attached. That is, it includes additional information to be attached to the Private Data field. Here, the additional information includes AC data, TMCC data, and a chip status information register. Since the size of the TMCC data or chip status information register does not exceed 178 bytes, it is not a problem to attach it to the Private Data field of the private section, but the situation is different for AC data. Since AC data has a small size of 204 bits and a large size of 2040 bytes, if the size of the AC data exceeds 178 bytes, it becomes difficult to attach to the Private Data field. Therefore, a separate method is required to attach AC data whose size exceeds 178 bytes to the Private Data field. This will be described with reference to FIG.

  FIG. 5 illustrates a method for including AC data in multiple private sections according to one embodiment of the present invention.

  The AC data (510) has a size exceeding 178 bytes. On the other hand, the AC data is divided for attachment to the Private Data field of the private section. That is, AC data having a size exceeding 178 bytes is divided into a plurality of data pieces having a maximum size of 178 bytes. An AC data piece having a size of 178 bytes is attached to the Private Data field of the private section, and since a plurality of AC data pieces are generated, they are attached to the Private Data field of the plurality of private sections. The data size of the AC data piece has 178 bytes excluding the last data piece, and the last data piece may be smaller than 178 bytes.

  TIE separates AC data divided and attached in multiple pieces from AC data so that the first piece of AC data has a TIE field value representing AC data, This piece has a value obtained by adding 1 to the TIE field value of the previous piece. That is, the first piece of AC data has a TIE field value representing AC data, and the second piece of AC data has a value obtained by adding 1 to the TIE field value representing AC data. This method informs that the AC data exceeds 178 bytes, and distinguishes each AC data piece exceeding 178 bytes.

  FIG. 6a illustrates a conventional system for transmitting chip status information between a receiving modem and an application, and FIG. 6b illustrates a system for transmitting chip status information between a receiving modem and an application according to an embodiment of the present invention. Indicates.

  As shown in FIG. 6a, in the conventional system, when the application requires the chip status information, the status information is periodically read out using the control path. Therefore, the modem software requires a separate software configuration for processing the status information and transmitting it. However, as in the embodiment of the present invention, if the null packet is attached to the chip status information register and transmitted together, the modem software does not require a separate software configuration as shown in FIG. Do not need. Along with this, the structure of the modem software is further simplified.

  FIG. 7a illustrates a system in which a conventional receiving modem transmits TS packets and additional information in an application, and FIG. 7b illustrates a system in which a receiving modem according to an embodiment of the present invention transmits TS packets and additional information in an application. .

  As shown in FIG. 7a, in the conventional system, in order to transmit the transmission stream data, the TMCC data, and the AC data by the receiving modem by the receiving modem, each data buffer must be provided separately. If a buffer for the transmission stream data is used without providing each data buffer, the transmission stream data, TMCC data, and AC data are all mixed and transmitted in a mixed state. In this case, there is no way to separate each data in the application. Therefore, in order to transmit each data according to an application in the conventional system, it is necessary to provide each buffer. However, in an embodiment of the present invention, when additional information can be attached to a null packet and transmitted, each data buffer is not required. Since the transmission stream data and the null packet can be distinguished, only one buffer of the transmission stream data may be used. Accordingly, the application can obtain necessary data by passing the transmitted null packet.

  The above description is merely an example of the technical idea of the present embodiment, and various modifications and variations can be made by those skilled in the art to which the present embodiment belongs without departing from the essential features of the present embodiment. can do. Therefore, the present embodiment is not intended to limit the idea of the present embodiment, but is for explanation, and the scope of the technical idea of the present embodiment is not limited by such an embodiment. The protection scope of this embodiment should be construed by the following claims, and all technical ideas within the equivalent scope should be included in the scope of rights of this embodiment.

110 Null packet
120 TS packet header
121 sync bytes
122 TI
123 PI
124 TP
125 PID
126 SC
127 AF
128 CC
130 payload
140 Private section
141 TID
143 SSI
145 PRI
147 PSL
149 Private data byte
210 Transmitter
220 Receiver
230 Receiving modem
240 modem software
250 decoder
260 receiving modem
310 Private section generator
320 Null packet generator
410 Null packet
420 TS packet header
421 sync bytes
422 TI
423 PI
424 TP
425 PID
426 SC
427 AF
428 CC
430 PF
440 payload
450 Private section
451 TID
452 SSI
453 PRI
454 RES
455 PSL
456 TIE
457 private data
510 AC data

Claims (13)

A data structure used in a video coding system,
The data structure of the private section stored in the packet is
A private data field containing data or information to be attached to the private section; and
A TIE (Table Identification Extension) field for distinguishing the type of data or information contained in the private data field;
PSL (Private Section Length) field representing the data size of the private data field and the TIE field,
As a field whose use was not defined, a RES (Reserved) field for maintaining the data size of the private section;
A PRI (Private Indicator) field indicating whether the format of the table follows the format of the private section;
When the field value is 0, there is the private data field, and when 1, the SSI (Section Syntax Indicator) field indicating that the extension format continues,
A TID (Table Identification) field (Field) indicating a value indicating that the section belongs to a private table, and
It has 0xff as the field value of the TID field,
The data or information to be attached to the private section is divided and attached in multiple pieces, and the field value of the TIE field for the first piece represents the data or information to be attached to the private section. A data structure having a TIE field value, wherein the field value of the TIE field for the next piece has a value obtained by adding 1 to the TIE field value of the previous piece. The video coding system includes:
The data structure according to claim 1, which is an MPEG (Moving Pictures Exports Group) -2 system . The private data field is
The data or information to be attached to the private section is one of AC (Auxiliary Channel) data, TMCC (Transmission and Multiplexing Configuration Control) data, and a chip status information register that the application needs to monitor periodically. The data structure of claim 1, wherein: The private data field is
4. The data according to claim 3, wherein when the data to be attached to the private section is the AC data, the AC data is divided and included so as to fit the data size of the private data field. Data structure. 5. The data structure according to claim 4, wherein each of the divided AC data is divided into a plurality of private data fields of a private section . The TIE field is
When the AC data is divided to fit the data size of the private data field, the TIE field values of the divided AC data pieces are different from each other in order to divide the pieces of the divided AC data. The data structure according to claim 4, wherein the data structure is set as follows . A data structure need use a video coding system (VideoCoding System),
The data structure of the null packet (Null Packet) stored in the packet is
TS packet header (Header) for determining whether or not it contains data having contents data packet embodied in TS (Transport Stream) packet form,
The payload (Payload) including the private section (Private Section) according to any one of claims 1 to 6 including data or information to be attached, and located between the TS packet header and the payload, PF (Pointer Field) for notifying that new data starts following the TS packet header,
A data structure containing The video coding system includes:
8. The data structure according to claim 7, wherein the data structure is an MPEG (Moving Pictures Exports Group) -2 system . The TS packet header is
8. The data structure according to claim 7, wherein the data structure has 1 as a PI (Payload Unit Start Indicator) field value included in the TS packet header . The PF is
8. The data structure according to claim 7 , further comprising 0 as a field value to indicate that new data starts following the TS packet header . The payload is
8. The data structure according to claim 7 , further comprising 0xff as a TID (Table Identification) field value of a private section included in the payload . A receiving modem of a receiver of a video coding system,
AC data received from a transmitter of the video coding system, TMCC data and applications among the status information register of the chip which requires periodic monitoring, claims 1 to 6, additional information including any one is attached A private section generation unit that generates the private section according to any one of the above, a null packet generation unit that generates a null packet including a private section generated from the private section generation unit,
A receiving modem characterized by comprising: The null packet generated by the null packet generator is transmitted by an application that requires one of the additional information, and is generated by the null packet generator using a TS buffer (Transport Stream Buffer). The receiving modem according to claim 12 , wherein a null packet is transmitted by the application.