KR20020014958A - PSI data filtering device for MPEG-2 system and control method thereof - Google Patents

Abstract

PURPOSE: An additional data filtering device of an MPEG-2(Moving Picture Expert Group-2) and a control method thereof are provided to enhance the filtering efficiency by performing section filtering by systematically relating with a PID(Packet Identification) and by preparing for a periodically repeated characteristic and an error based on modes. CONSTITUTION: An additional data filtering device of an MPEG-2 comprises a synchronous detector(1) receiving the input of a transport packet, a TS(Transport) header analyzer(2) analyzing the header of the transport stream inputted from the synchronous detector, a memory interface(3) for interface with an external memory(4), an STC controller(5), a controller(6) storing the data having a packetized element stream format in the external memory and storing the data having other formats in the external memory after section filtering, a section filtering unit(7), and a PES(Packetized Element Stream) header analyzer(8) analyzing the header of the packetized element stream and outputting the result to a video decoder(9) and an audio decoder(10). Therefore, the efficiency of data filtering is enhanced.

Description

PSI data filtering device for MPEG-2 system and control method

The present invention relates to an apparatus for filtering additional information data of an MPEG-2 system and a method of controlling the same. More specifically, the present invention relates to a method for filtering section information and to perform section filtering in organic connection with the packet identification. The present invention relates to an additional information data filtering device of an MPG-2 system and a method of controlling the same, which improves the filtering efficiency by being able to prepare for a periodically repeated characteristic and an error in transmission.

In general, when the audio signal or the video signal is reproduced digitally, the digital method is increasingly preferred because the quality of reproduction is higher and more faithful than the analog method. However, since the digital method has a larger amount of data to be transmitted than the analog method, research has been made on a method of reducing the amount of data to be transmitted by compressing and encoding a transmission data signal. The Joint Photographic Expert Group (JPEG) and the Moving Picture Expert Group (MPEG), which are international standardization standards for video signal encoding methods under the International Organization for Standardization and the International Electrotechnical Commission, have been working to standardize the compression encoding method for video signals.

In the case of MPEG-2, which is widely known as a moving picture compression method, in addition to moving picture data, audio data compression and system layers for changing them to be suitable for transmission are also defined.

In MPEG-2, image data and audio data are encoded in respective elements to create an elementary stream (ES), and then packaged again to form a packetized elementary stream (PES). Make. Attaching a pack header to store this makes the program stream used for the DVD. When the packet is packetized into a size of 188 bytes to transmit the packet, a transport packet having a structure as shown in FIG. 1 is formed, and a stream for transmitting the packet is called a transport stream.

The transport stream includes program specification information such as a program associative table (PAT) and a program map table (PMT) together with main data such as video data and audio data. Information, PSI) additionally. In addition, the American Advanced Television Systems Committee (ATSC) standard and the European Digital Video Broadcasting (DVB) standard have expanded the program specification information (PSI) according to each standard. The video audio data is transmitted by being contained in the packetized element stream (PES) mentioned above in a transport stream, but the program specification information (PSI) data is transmitted in a format called a section.

Packets with payload for each video data, packets with payload for audio data, and packets with payload for various additional information are packet identifications (Packet IDentification (PID)) of 13 bits in the header. Separated by.

The demultiplexer in the MPEG-2 system first looks for the Program Assistance Table (PAT) when the above transport stream is input. The above program association table (PAT) is transmitted in the above-mentioned section format, and the packet identification (PID) of this packet is 0x0000.

When the program association table PAT is found, the packet identification PID including the program map table PMT is found by decoding the information of the program association table PAT. The program map table (PMT) describes a packet identification (PID) list and accessory information of a transport packet in which individual bit strings such as video and audio constituting a program are transmitted.

In this case, unlike the packetized element stream (PES) that handles the element stream (ES) encoding video or audio data, in the case of the program additional information (PSI), in order to enable fast access to include information related to a program You will have redundancy. That is, the same information is frequently sent so that the decryption can be started quickly at any time. For example, the US ATSC standard requires information to be sent within at least 0.1 seconds for the Program Assistance Table (PAT) and within 0.4 seconds for the Program Map Table (PMT). Therefore, if the program association table (PAT) is not present, the packet identification (PID) of the program map table (PMT) cannot be known. Accordingly, the packet identification (PID) of video and audio cannot be known. The system becomes inoperable.

In most cases, however, this information is unchanged and will send the same information that was sent before. Therefore, the ordinary transport decoder has an algorithm for effectively processing such redundant side information data, and there is a section filtering prescribed in the European Digital Video Broadcasting (DVB) standard as a widely known method. Indeed, the Digital Video Broadcasting (DVB) specification stipulates more than 32 section filters of more than 8 bytes.

The conventional method of filtering additional information data is based on data of a table ID, a version number, a section number, and the like among inputted section data. Section filtering is performed continuously without any help, i.e. without any load on the microcontroller.

However, in the conventional method of filtering additional information data, the size of hardware can be reduced slightly because the source ID cannot be checked decisively, but the ATSC standard PSIP information, the ETSI DVB SI information, and the like can be used. There is a problem in that the filtering efficiency is lowered because it cannot filter properly.

An object of the present invention is to solve such a conventional problem, and checks packet identification (PID) and performs section filtering in organic connection with this. The present invention provides an apparatus for filtering additional information data of an MPEG-2 system and a method of controlling the same, which improves the filtering efficiency by preparing for a transmission error.

1 is a block diagram of a general transport packet.

2 is a block diagram of an additional information data filtering device of an MPEG-2 system according to an embodiment of the present invention.

3 is a flowchart illustrating a method of controlling an apparatus for filtering additional information data of an MPG-2 system according to an embodiment of the present invention.

4 is a block diagram of a register of an additional information data filtering device of an MPEG-2 system according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

1: Sync detector 2: TS header analyzer

3: memory interface 4: external memory

5: STC control unit 6: control unit

7: section filtering unit 8: PES header analysis unit

9: video decoder 10: audio decoder

As a means for achieving the above object, the configuration of the apparatus of the present invention comprises: synchronous detecting means for accepting an input of a transport packet; TS header analyzing means for analyzing and outputting the header of the transport stream inputted from the synchronous detecting means; Memory interface means for interfacing with external memory; Check the packet identification so that the payload is stored in the external memory through the memory interface means if the payload is data in the form of packetized element stream such as video and audio. Control means for storing only necessary data in the external memory after filtering; Section filtering means for section filtering; And PES header analyzing means for reading the section data stored in the external memory, analyzing the header of the packetized element stream, and outputting the header to the video decoder and the audio decoder.

As a means for achieving the above object, the configuration of the method of the present invention comprises the steps of: analyzing a transport stream header by inputting a packet when operation begins; Checking the packet identification and reading the section filter control register at the position mapped to the bit position of the current packet identification in the case of section data; Checking each bit of the section filter control register sequentially by checking whether the current bit value is 1 or 0, and if the current bit value is 0, increasing the bit value by 1 to check the next bit; Reading a filter mode value to determine a method for filtering data and mask corresponding to the position of the bit value if the current bit value is 1; Checking whether the read filter mode value is 1 or 0; If the filter mode value is 1, the data corresponding to the current bit position of the section filter control register and the mask are read. If the data of the input section and the stored section data are the same, it is the section to be accepted. Checking the next bit of the filter control register; If the filter mode value is 0 and the data corresponding to the current bit position of the section filter control register and the data of the input section and the stored section data are different, the section to be accepted is stored. And checking the next bit of the section filter control register.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings in order to describe in detail enough to enable those skilled in the art to easily carry out the present invention. .

For reference, the embodiments disclosed herein are only presented by selecting the most preferred examples to help those skilled in the art from the various possible examples, the technical spirit of the present invention is not necessarily limited or limited only by this embodiment. .

As shown in Fig. 2, the configuration of the additional information data filtering device of the MPEG-2 system according to the embodiment of the present invention includes a synchronization detector 1 for accepting an input of a transport packet and the synchronization described above. TS header analyzer 2 for analyzing and outputting the header of the transport stream input from detector 1, memory interface 3 for interfacing with external memory 4, STC controller 5, and packets If the packet is not received and the packet is not accepted, it is discarded. If the packet is not received, the packet is processed according to the characteristics of the packet. If the payload is data having a packetized element stream (PES) type such as video audio, the memory interface 3 To be stored in the external memory (4) via section), and the data having a section form is subjected to section filtering and only necessary data is stored in the external memory (4). The control unit 6, the section filtering unit 7 for section filtering, the section data stored in the external memory 4, and read the header of the packetized element stream to analyze the header of the packetized element stream. The PES header analyzing unit 8 outputs the decoder 10.

As shown in FIG. 3, the configuration of the method for controlling the additional information data filtering device of the MPG-2 system according to an embodiment of the present invention includes the steps of starting operation (S1) and inputting a packet ( S2), analyzing the TS header (S3), checking the packet identification (PID) (S4), and 32 bit positions of the current packet identification (PID) in the case of section data. (S5) reading a section filter control register at a position mapped with (S5), checking each 32 bits from 0 to 31 sequentially to determine whether the current bit value is 1 or 0 (S6), and the current bit. If the value is 0, checking the next bit by increasing the bit value by 1 (S7), and if the current bit value is 1, the filter to determine a method for filtering the data and mask corresponding to the position of the bit value described above. Step (S8) of reading a mode value and reading Checking whether the on filter mode value is 1 or 0 (S9); reading data and mask corresponding to the current bit position of the section filter control register when the filter mode value is 1 (S10); If the 8 bytes of the input section and the stored section data are the same, the value must be taken into consideration. Therefore, storing the result in external memory and checking the next bit of the section filter control register (S11), and the value of the filter mode register. If 0, the step of reading data and mask corresponding to the current bit position of the section filter control register (S12), and considering the mask value, if the 8 bytes of the input section and the stored section data are different, they should be accepted. Since it is a section, it is stored in the external memory and if it is the same, checking the next bit of the section filter control register (S13) and storing it in the external memory (S1). 4) is made, including.

With the above configuration, the functions of the additional information data filtering device of the MPG-2 system and its control method are as follows.

When power is applied and operation starts (S1), a transport packet is input to the synchronization detector 1 (S2).

The transport packet input to the synchronous detection unit 1 is output to the TS header analyzer 2 via the synchronous detector 1, and the header of the transport stream TS is transmitted by the TS header analyzer 2 to the header. It is analyzed (S3). In this case, a sync byte constituting the header of the transport stream TS, a transport error indicator, a payload unit start indicator, and a transport priority ), Packet identification (PID), transport scrambling control, adaptation field control, continuity counter, adaptation field and the like are extracted.

Video, audio, and side information each have a packet identification (PID). Accordingly, there are 32 packet identifications (PIDs) that can be identified as shown in FIG. Each of the 32 packet identifications (PIDs) is one-to-one mapped with the section filter control register. That is, there are 32 checkable packet identifications (PIDs) in total from 0 to 31, and the positions of each packet identification (PID) are one-to-one mapping with the section filter control registers.

Next, the control unit 6 checks the packet identification (PID) and discards any packets that are not accepted. If the packets are not to be received, the control unit 6 processes the packets according to the characteristics of the packets. In the case of the data having the form of), the data having the form of section is stored in the external memory 4 via the memory interface 3, and the data having the section form is subjected to section filtering so that only necessary data is stored in the external memory 4.

The above-described section filtering process is described in detail as follows.

The control unit 6 reads the value of the section filter control register at the position mapped to 32 positions from 0 to 31 of the current packet identification PID (S5). The position of each bit of the 32-bit section filter control register read in this way represents the positions of the 32-bit 64-bit data register and the mask register. That is, if the value of the 0th bit of the 32 bits of the section filter control register is 1, the data and mask of the 0th data register and the mask register among the 32 data registers and the mask registers are read, and the first 8 bytes of the currently input section are read. To filter.

The control section 6 sequentially checks each of the 32 bits I of the section filter control register from 0 to 31, whether the current value is 1 or 0 (S6).

If the current value of each bit I of the section filter control register is 0, the control section checks the next bit by incrementing the bit I by one (S7).

If the current value of each bit I of the section filter control register is 1, the controller 6 reads and filters the data and mask of the data register and mask register corresponding to the position of the bit I described above. To determine, the filter mode value of the filter mode register is read (S8).

The control section 6 checks whether the filter mode value read from the filter mode register is 1 or 0 in this way (S9).

When the value of the filter mode register is 1, the controller 6 reads data and masks of the data register and mask register corresponding to the I position of the section filter control register (S10).

Next, the controller 6 considers the mask value, and if the 8 bytes of the input section and the stored section data are the same, it is a section to be accepted, so that it is stored in the external memory 4, and the 8 bytes of the input section are stored. If the section data is different, the next bit of the section filter control register is checked by increasing the I value by one (S11).

On the other hand, when the value of the filter mode register is 0, the controller 6 reads data corresponding to the I position of the section filter control register and data and mask of the mask register (S12).

Next, the control unit 6 considers the mask value and stores the data in the external memory 4 because the 8 bytes of the input section and the stored section data are different. If the section data is the same, the next bit of the section filter control register is checked by increasing the I value by one (S13).

Therefore, section data is classified and stored in the external memory 4 according to the filter mode value read from the filter mode register (S14).

The microcontroller of the PES header analyzer 8 reads the section data stored in the external memory 4, analyzes the packetized element stream (PES) header, and sends the packetized element stream (PES) header to the video decoder 9 and the audio decoder 10, respectively. .

As described above, in the embodiment of the present invention, the section filtering is performed in association with the packet identification check, and the section filtering is also set so that the filtering can be prepared for the characteristics that are periodically repeated and errors in transmission. It is possible to provide an additional information data filtering device of an MPEG-2 system and a method of controlling the same. Such effects of the present invention can be applied to various applications within the scope of the technical idea of the present invention in the field of MPEG-2 systems.

Claims (5)

Synchronous detecting means for accepting an input of a transport packet; TS header analyzing means for analyzing and outputting the header of the transport stream inputted from the synchronous detecting means; Memory interface means for interfacing with external memory; Check the packet identification so that the payload is stored in the external memory through the memory interface means if the payload is data in the form of packetized element stream such as video audio, and the section-type data is sectioned through the one-to-one mapping with the section filter control register. Control means for storing only necessary data in the external memory after filtering; Section filtering means for section filtering; And Additional information data of the MPEG-2 system, comprising: a PES header analyzing means for reading section data stored in an external memory, analyzing a header of a packetized element stream, and outputting the header to a video decoder and an audio decoder. Filtering device. The method of claim 1, And the section filter control register is 32 bits in size. The method of claim 1, The above-described section filter control register is an additional information data filtering device of an MPEG-2 system, wherein each bit position is mapped to a data register and a mask register of the same number of bits. The method of claim 1, The above section filtering is based on the filter mode value of the filtering mode register, and when the filter mode value is 1, the data of the section inputted by reading the data and mask corresponding to the current bit position of the section filter control register and the stored section If the data is the same, it is the section to be accepted. If it is different, save it in external memory and if it is different, check the next bit of the section filter control register. If the filter mode value is 0, read the data and mask corresponding to the current bit position of the section filter control register. 2. The additional information data filtering device of the MP-2 system, characterized in that the section to be accepted if the data of the input section and the stored section data are different, is stored in the external memory and the next bit of the section filter control register is checked if they are the same. Analyzing a transport stream header by inputting a packet when an operation starts; Checking the packet identification and reading the section filter control register at the position mapped to the bit position of the current packet identification in the case of section data; Checking each bit of the section filter control register sequentially by checking whether the current bit value is 1 or 0, and if the current bit value is 0, increasing the bit value by 1 to check the next bit; Reading a filter mode value to determine a method for filtering data and mask corresponding to the position of the bit value if the current bit value is 1; Checking whether the read filter mode value is 1 or 0; If the filter mode value is 1, the data corresponding to the current bit position of the section filter control register and the mask are read. If the data of the input section and the stored section data are the same, it is the section to be accepted. Checking the next bit of the filter control register; And If the filter mode value is 0, the data corresponding to the current bit position of the section filter control register and the mask are read. If the data of the input section is different from the stored section data, it is the section to be accepted. And controlling the next bit of the filter control register.