KR100698149B1 - Method and Apparatus for Section data filtering - Google Patents

Abstract

The present invention relates to a method and apparatus for filtering section data. The present invention provides a filter input controller that edits and rearranges only fields used for actual filtering among input section data, registers storing field-specific information for byte filtering by PID for reordering, and the actual section filtering. An apparatus for filtering section data comprising a FIFO storing only a reference data field used in the and a section filter for comparing the rearranged input section data with reference data stored in the FIFO and outputting matching data. Therefore, according to the present invention, it is possible to reduce the storage of unnecessary reference data by reconfiguring and filtering only necessary fields from the input section data during section filtering, thereby minimizing the cost of hardware saving.

Section Data, Filtering, PID, Reference Data, Filter Input Controllers

Description

Method and apparatus for filtering section data {Method and Apparatus for Section data filtering}

1 shows a private section as defined in ISO / IEC 13818-1.

2 is a diagram illustrating a section filtering method according to the prior art.

3 is a diagram illustrating a structure of a PSIP used in a general ATSC

4 is a view showing the configuration of a section filter according to the present invention.

5 is a diagram illustrating an example of setting a section filter field setting register according to the present invention.

6 is a diagram showing the configuration of data edited in a filter input controller according to the present invention.

-Explanation of symbols for the main parts of the drawings-

100: filter input controller 200: section filter field setting register

300: section filter 400: reference data FIFO

The present invention relates to filtering of section data, and more particularly, to a method and apparatus for reconstructing and filtering only necessary fields from input section data when filtering MPEG 2 section data.

Recently, many digital broadcasts use the MPEG 2 standard for video compression and transmission and reception. In the MPEG 2 system standard (ISO / IEC 13818-1), which is a standard for transmitting compressed video or audio data, the PSI (Program Specific Information) is also transmitted as program information on transmitted audio, video, and other data. It is prescribed to do.

In addition, in order to transmit various types of program information in addition to the PSI data defined in the MPEG 2, ATSC (Advanced Television System Committee) uses PSIP (Program and System Information Protocol), and DVB (Digital Video Broadcast) (SI) Etc. are prescribed.

Unlike the audio and video data, such program data transmits the same information periodically so that a user can obtain accurate program information at any time.

Therefore, in order to avoid redundant decoding of program data, a system decoder of a receiver installs a filter and selects only desired data.

Such program information is transmitted in the section data format defined in the MPEG 2 system standard. Filtering this data is called section filtering.

1 is a view showing a private section defined in ISO / IEC 13818-1.

The section format as shown in FIG. 1 is a format that all broadcasts following the MPEG 2 standard take. Of course, the PSI data also follows the private section by default, although the purpose of each field is different.

According to the private section of FIG. 1, the length of the section header excluding the “data_byte” field part may vary according to the value of “section_syntax_indicator”.

However, most section filters filter 8 bytes of data from the "table_ID" field, or a few more bytes in addition to 8 bytes, depending on the separate format specified in the PSIP or SI.

This filtering method will be described with reference to the accompanying drawings.

2 is a diagram illustrating a section filtering method according to the prior art.

As shown in FIG. 2, the section filtering apparatus includes a section filter 10 that compares a transmitted input section with stored reference data and outputs a matching section, and reference data and mask data. ) Includes a stored first in first out (FIFO) (storage medium such as memory, register, etc.) 20.

The filtering device configured as described above receives data to be used for filtering for 8 bytes or more from the “table_id” field among the sections input by the section filter 10, and compares the data with the data stored in the reference data FIFO 20 to match the data. The filtering is performed by outputting the.

In this case, the data input to the section filter 10 is a collection of continuous data starting from the "table_id" field, and most of the continuous data from the "table_id" is not used for filtering. Therefore, in order to display data to be used for filtering among the data input to the section filter 10, a mask is stored together with the reference data and used.

In addition, the "Private_data_byte" field part, which is used differently for each broadcast standard, is stored after filtering, and then parsed by software (S / W) as necessary.

However, the method of collecting and filtering continuous fixed length data from the "table_id" field not only collects data that will not be used for filtering, but also occupies reference data corresponding to the same location. This leads to waste of the reference data FIFO 20.

In addition, if additional filtering is required for the "Private_data_byte" field portion after the data filtered by the hardware, scalability is reduced, and the processing of the data is a burden on the CPU.

On the other hand, Figure 3 is a diagram showing the structure of the PSIP used in the general ATSC.

As shown in FIG. 3, the PSIP structure of ATSC basically defines a header area of 9 bytes excluding the data area by placing a "Protocol_version" field after the "Last_section_number" field defined in the private section of ISO / IEC 13818-1.

As such, each broadcasting standard may have a different format, and the data portion may also require additional filtering according to the type of program information.

However, in the conventional method, for example, when only the "table_id" and the "Protocol_version" are to be filtered out, fields such as "section_number" and "last_section_number" between them are also collected from the input section and input to the section filter 10. In addition to the reference data FIFO 20, data of various formats must be input to match the byte position. That is, in order to store the reference data of "table_id" in the first byte of the reference data FIFO 20 and to store the "Protocol_version" data, the byte positions corresponding to the fields existing therebetween are also transmitted in the FIFO 20. Since it must be secured will be a waste of the FIFO (20).

In addition, extending the filtering to the data domain in the same manner further increases the waste.

Therefore, there is a need for a new filtering method that can efficiently use the reference data FIFO 20 and extend the filtering to the data portion.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to allow a user to directly designate data to be used for section filtering among inputted section data, thereby improving hardware utilization in a section filter and for more data. It is an object of the present invention to propose a section filtering method and apparatus for performing filtering.

In order to achieve the above object, the present invention provides a filter input controller for editing and reordering only fields used for actual filtering among input section data, and information for specifying a field for section filtering by PID for byte reordering is stored. A section data including a register, a FIFO storing only a reference data field used for the actual section filtering, and a section filter for comparing the rearranged input section data with reference data stored in the FIFO and outputting matching data. Provides a filtering device.

The register is set for each PID, and each bit of the register set for each PID indicates each byte of the input section data.

The filter input controller generates and outputs a masking signal corresponding to the length of the rearranged section filter data.

The reference data FIFO may include and store mask data for distinguishing the rearranged section data.

According to the present invention, there is provided a method of storing information for rearranging only fields used for actual filtering among input section data, editing and rearranging the input section data according to the stored information, and using the actual section filtering. And storing the reference data field, and comparing the rearranged input section data with the reference data field and outputting matching data.

In order to reorder only fields used for actual filtering among the input section data, a field for section filtering for each PID may be designated and stored for each byte.

Therefore, according to the present invention, it is possible to reduce the storage of unnecessary reference data by reconfiguring and filtering only necessary fields from the input section data during section filtering, thereby minimizing the cost of hardware saving.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

In addition, the term used in the present invention was selected a general term that is widely used at present, but according to the emergence of a new technology, the term that the applicant deemed most appropriate in the present invention was arbitrarily used, and the meaning of the term in the corresponding description. It will be explained clearly. Therefore, in the understanding of the present invention, it is intended that the present invention should be understood as the meaning of terms rather than simple names of terms.

4 is a view showing the configuration of a section filter according to the present invention. Where the more detailed description of the present invention is required before the description will be described with reference to the accompanying drawings.

As shown in FIG. 4, the section filtering apparatus according to the present invention includes a filter input controller 100 for editing input section data for section filtering, and a field for section filtering for each PID (Packet IDentifier). And a section filter 300 and a reference data FIFO 400.

The section filtering apparatus configured as described above maximizes the efficiency of the FIFO 400 by storing only the fields used for actual section filtering in the reference data FIFO 400.

To this end, the input section data is also required to reconstruct the same pattern as the pattern stored in the FIFO 400, the filter input controller 100 performs this operation.

That is, only the fields to be actually filtered are extracted from the input data section sequentially inputted from the "table_ID" field and made into the input of the section filter 300.

In addition, for the above operation, the register 200 for specifying the field to be used for filtering, including the header and data of the section filter for each PID, is provided.

The section filter field setting register 200 will be described in more detail as follows.

As described above, the purpose of the register 200 is that the filter input controller 100 extracts only the data to be used for actual filtering from the input section data and passes the data to the section filter 300 so that the input section data is passed to the section filter 300. Is to randomly specify the data to be used for filtering.

To this end, the register 200 is set for each PID, and each bit of the register allocated for each PID indicates each byte of input section data. That is, each bit position of the register 200 indicates a byte position of an input data section. The bits are applied in order of Most Significant Bit (MSB), so that the MSB in register 200 points to the "table_ID" of the input section data.

The total number of bits in the register 200 represents a range from which data to be used for section filtering can be extracted from the input section data. That is, when using a 32-bit register, you can set the desired data among 32 bytes of data starting from the "table_ID" field of the input section data.

Also, the number of enabled bits among the total bits is limited according to the maximum number of bytes that the section filter 300 can filter, that is, the byte width of the reference data FIFO 400 to be used.

For example, if the section filter 300 filters up to 8 bytes, the data width of the reference data FIFO 400 becomes 8 bytes, and the enable bit of each field control register 200 has. The number is limited to eight. In this case, if the number of enable bits of the register 200 is 8 or more, the priority is made in order of MSB.

The contents of the register 200 set for each PID are applied to all sections in the packet even when a plurality of sections are included in one transport packet. In this case, however, a mask of the reference data FIFO 400 is used to apply a different mask to various sections in the packet.

An example of setting an actual register in the section filter field setting register 200 is shown in FIG. 5, which will be described below with reference to FIG. 5.

As shown in FIG. 5, when the section filter field setting register 200 is set, the input data includes "table_id" and 5th byte, 10th byte, 11th byte, 12th byte except the lower 8 bits of "section_length". A total of six bytes of the 13th byte can be used for filtering.

As such, the filter input controller 100 edits data to be used for section filtering from the input section data according to the contents set in the section filter field setting register 200.

To this end, the filter input controller 100 first receives information about which PID the transport packet has passed and which PID filter has passed, and reads the section filter field setting register 200 corresponding thereto.

As described above, the register 200 contains information on fields to be used for actual filtering as shown in FIG. 5.

Therefore, if the setting is the same as that of FIG. 5, the filter input controller 100 may extract data of all 6 bytes of "table_id", 5th byte, 10th byte, 11th byte, 12th byte, and 13th byte from the input section data. It is to construct.

The section filter 300 receiving the data reads and filters the reference data stored in the reference data FIFO 400.

In this case, the length of the section filter 300 should be predetermined, and accordingly, the byte length of the reference data FIFO 400 is determined. However, when the reconstructed data for filtering is 6 bytes, if the filtering length of the section filter 300 is 6 bytes or more, and thus the bytes read from the reference data FIFO 400 are 6 bytes or more, the reconstructed data You do not know where to compare the byte data between the and reference data.

Therefore, together with the reconstructed section data, a control signal for how many bytes of the reconstructed data for the data of the maximum filtering length should also be transmitted to the section filter 300. In other words, if the filtering length is 8 bytes, the masking data, which says that only 6 bytes of the 8 bytes should be compared with the 6 bytes of data, should be passed.

Accordingly, the output of the filter input controller 100 becomes a masking signal for the length of data passed by the filter input controller 100 among the section filter data and the maximum section filtering byte length.

6 is a diagram illustrating a configuration of data edited in the filter input controller according to the present invention.

6 illustrates a data editing example according to the field setting of FIG. 5 described above, and illustrates a case in which the maximum filtering length of the section filter 300 is 8 bytes.

That is, according to the masking data stored in the section filtering field setting register 200, the original input section data has a total of 6 bytes of "table_id", 5th byte, 10th byte, 11th byte, 12th byte, and 13th byte. It is edited to the length, and the maximum filtering length is 8 bytes, so the masking data generates and outputs 8-bit masking data having two bits of 0 at the rear end.

On the other hand, since the method according to the present invention generates only the data to be used for the actual filtering through the filter input controller 100, the reference data FIFO 400 also matches the byte position of each reconstructed data, so that only the reference data necessary for the actual filtering is provided. Will be saved.

That is, as shown in FIG. 6, when the input section data is reconstructed, the reference "table_id", the fifth data, the tenth data, the eleventh data, and the twelfth so that the reference data FIFO 400 has the byte position as shown in FIG. Data, and the 13th data must be stored in order.

Therefore, even if the maximum filtering length is 8 bytes, since masking data for this is generated from the filter input controller 100, only 6 bytes of the front end is valid data used for filtering.

The mask data in the reference data FIFO 400 is used to distinguish the masking data generated from the filter input controller 100 by using a mask again in the reconstructed section data.

Meanwhile, the section filter 300 used in the present invention receives section data and masking data obtained by reconstructing only data necessary for filtering from the filter input controller 100. Then, the data is read from the reference data FIFO 400 to determine whether it matches the input section data, and outputs the matched data. At this time, the masking data input from the filter input controller 100 and the mask data stored in the reference data FIFO 400 are in AND relationship with each other.

The present invention is not limited to the above-described embodiments, and can be modified by those skilled in the art as can be seen from the appended claims, and such modifications are within the scope of the present invention. .

The effects of the method and apparatus for filtering section data according to the present invention described above are as follows.

First, by reconfiguring and filtering only necessary fields from the input section data when filtering the section, unnecessary storage of reference data can be reduced, thereby minimizing the cost of hardware saving.

Second, it is easy to expand the range of the section data that can be included in the filtering using limited hardware, thereby reducing the load on the software, thereby freeing up CPU resources.

Claims (9)

In filtering section data, A register having first information specifying a byte of section data input by a predetermined number of bits and second information on enabling of each bit constituting the first information; A filter input controller configured to generate a comparison control signal for the first data reconstructed using the first information and the second information and the first data and the reference data; A FIFO for storing reference data for the byte position of the first data; And And a section filter configured to compare and filter the first data and reference data using the comparison control signal. The method of claim 1, If the length of the first data is longer than the length of the predetermined reference data, the comparison control signal And information for designating a data to be compared with the reference data among the data constituting the first data using bits allocated by the length of the first data. The method of claim 2, The designating apparatus of claim 1, wherein the length of the reference data is specified from the MSB of the first data. The method of claim 1, When the length of the first data is shorter than the length of the predetermined reference data, the comparison control signal may include: And all of the data constituting the first data with the bits allocated by the length of the reference data are designated as data to be compared, and the remaining bits among the allocated bits are designated as not to be compared. . In filtering section data, Generating first information specifying a byte of section data input by a predetermined number of bits and second information about enabling of each bit constituting the first information; Reconstructing section data to be used for filtering by using the generated first information and second information and generating a comparison control signal for the reconstructed section data and reference data; Storing reference data for the byte position of the reconstructed section data; And And comparing and filtering the reconstructed section data with reference data using the comparison control signal. The method of claim 5, If the length of the first data is longer than the length of the predetermined reference data, the comparison control signal And information specifying data to be compared with the reference data among the data constituting the first data using bits allocated by the length of the first data. The method of claim 6, In the specifying, characterized in that for specifying from the MSB of the first data by the length of the reference data. The method of claim 5, When the length of the first data is shorter than the length of the predetermined reference data, the comparison control signal may include: Each data constituting the first data using bits allocated by the length of the reference data is designated as data to be compared, and the remaining bits among the allocated bits are designated as not to be compared. . delete

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