KR100565651B1 - Apparatus for decoding video user data in DTV and for the same - Google Patents

Abstract

The present invention relates to a video decoder of a digital TV, and more particularly, to an apparatus and method for decoding a video of a digital TV video user data. The present invention initializes the digital TV so that the host processor selectively sets the user data decoding mode; Detecting start code when user data is input; If the start code is detected, determine whether or not the setting mode is matched, and if so, decode the user data and temporarily store the decoded user data in a FIFO in units of bytes; Storing user data of a predetermined size in the FIFO and storing it in a memory; By checking the sequence of user data stored in the memory and selectively reading out specific user data to the host processor at the end, the user data can be decoded to suit the needs of the host processor and only the necessary data can be decoded selectively. It can reduce the memory to store the data, and also allows the host processor to efficiently manage and control the entire system.

Syntax Parser, User Data, Decode, FIFO

Description

Apparatus for decoding video user data in DTV and for the same}

1 is a diagram showing an apparatus for decoding video user data of a digital TV according to the present invention.

2 is a flowchart illustrating a method of decoding video user data of a digital TV according to the present invention.

* Brief description of drawings *

11: syntax parser 12: host processor

13: user data decoder 14: FIFO

15: memory 16: video decoder

The present invention relates to a video decoder of a digital TV, and more particularly, to an apparatus and method for decoding a video of a digital TV video user data.

 Currently, a movie sequence compressed to the Moving Picture Expert Group (MPEG) standard includes various user data such as closed caption, display information, and 3: 2 pull-down information. data) is included.

The decoding of such user data and the decoding method corresponding to the received information are implemented differently depending on the receiving system and decoded by hardware or software as necessary.

The user data does not have much data compared with video or audio data, and thus the bit rate transmitted is not very high.

Accordingly, most video decoders handle hardware search and decoding of video data at the video level, and control of each component block in terms of system processing by data processing or information processing by detailed data analysis is performed by software.

According to the MPEG standard, user data on a video bit stream can be transmitted in various levels.

That is, it is inserted and transmitted in the sequence header level, the GOP header level, the picture header level, and the like. The insertion level is determined according to the purpose.

For example, text information indicating characteristics of a video sequence is transmitted at a sequence level, and information of a closed caption (DTV-CC), which is caption information of each picture, is transmitted at a picture level.

User data may be transmitted by inserting different information according to the characteristics of each digital TV broadcasting standard in addition to different transmission methods according to the level.

When inserting user data according to other broadcasting standards, it is common to insert valid data after inserting a specific identifier.

As examples of the use of video user data, first of all, DSS (Digital Satellite System), a North American satellite digital broadcasting standard, has a problem of compatibility between SD transmission method, HD transmission method, and existing content. The user data is used as a method for ensuring compatibility as a new broadcast standard is transmitted.

For example, if the content that was created is not appropriate for 3: 2 pulldown information to adjust the frame rate or pan-scan information indicating the display offset, this information may be added to the picture level user data. Insert and send

In another example, in the DTV-CC standard, which is a digital caption broadcasting of ATSC (Advanced Television Standard Committee), a terrestrial digital broadcasting standard in North America, subtitle information data corresponding to each picture is inserted after inserting an ATSC identifier into a user data area of each picture level. Insert

For example, in the European Digital Broadcasting Standard (DVB) standard, the aspect ratio, screen size, and the like, which are display indication information of each video screen, are displayed in the user data area of the picture level with AFD (Active Format). Descriptor) Inserted with identifier.

As such, user data is inserted at various levels of the MPEG sequence, and various types of information are transmitted according to its contents and uses.

Accordingly, an object of the present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to quickly and error-freely obtain various types of user data for a host processor to control a receiver system or display corresponding data. Disclosed is an apparatus and method for decoding a video user data of a digital TV that are stably transmitted.

According to an aspect of the present invention for achieving the above object, a syntax parser for retrieving the video sequence received from the transmitter to extract the video signal and the user data; A video decoder for reconstructing a moving picture from the video signal encoded compressed data extracted from the syntax parser; A user data decoder which decodes user data extracted by the syntax parser; A FIFO for temporarily storing user data decoded by the user data decoder; A memory for collecting and storing data stored in the FIFO in predetermined units; When the user data decoding mode is set during initialization, and a start code is detected from the user data input from the syntax parser, the user data decoding unit is configured to determine whether or not the setting mode is matched and to decode the user data if it is matched. And a host processor for controlling and checking a sequence of user data stored in the memory and selectively reading specific user data in the last case.
The host processor controls the function of the user data decoder in units of levels or reads caption information of user data stored in the memory and transfers the caption information to the video decoder to display on the display screen.
The video decoder unit receives decoding information or subtitle broadcasting included in the user data from the processor to the host to adjust or change the configuration of each screen element for the display screen or to adjust the screen size.
The user data has a start code for distinguishing each data, and preferably, data until the second start code is detected from the byte data after the first start code of the user data is divided into one user data.

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According to another aspect of the present invention for achieving the above object, the step of initializing the digital TV to the host processor to selectively set the user data decoding mode; Detecting a start code when user data is input; If the start code is detected, determining whether the set mode is matched, and if the start code is matched, decoding the user data and temporarily storing the decoded user data in a FIFO in units of bytes; Storing user data of a predetermined size in the FIFO; And checking the sequence of user data stored in the memory to selectively read specific user data into the host processor when the last time.
The user data decoding mode includes at least one of whether to decode according to a user data level, whether to decode according to a selected identifier, an identifier setting, a location of a memory to store user data, and whether to insert a user data header.
When the transmission level does not belong to the set level, at least one or more of a sequence start code, a group start code, and a picture start code, which are levels at which user data can be transmitted, are separated and detected.
Checking the sequence of user data and determining whether to continue collecting user data in a FIFO on a predetermined basis.
The host processor checks the memory location and the number of user data in which the user data is stored and reads it from the memory to use for system control.
When storing the user data in the memory, a header for displaying error prevention and characteristics of each user data is further inserted and stored.
Hereinafter, the configuration and operation according to an embodiment of the present invention will be described with reference to the accompanying drawings.

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1 is a diagram illustrating an apparatus for decoding video user data of a digital TV according to the present invention.

Referring to FIG. 1, the apparatus for decoding video user data of a digital TV according to the present invention includes a syntax parser 11 which searches for a video sequence received from a transmitter and extracts a video signal and user data, and the encoding extracted from the syntax parser. A video decoder unit 16 for restoring a moving picture from the compressed data, a user data decoder 13 for decoding the extracted user data, a FIFO 14 for temporarily storing the decoded user data, and the FIFO ( And a host processor 12 which controls the user data decoder 13 and reads out the data stored in the memory 15.

Referring to the video user data decoding apparatus of the digital TV configured as described above is as follows.

The syntax parser 11 retrieves a video sequence and extracts various data necessary for video decoding. Video data such as DCT coefficients, motion vectors, and header information necessary for actual video reconstruction are transmitted to the video decoder 16, and the video user data is transferred to the user data decoder 13.

The host processor 12 is responsible for the basic function setting of the syntax parser 11, the user data decoder 13, and the video decoder 16, and the organic function setting of each element for a desired operation of the entire system. For example, settings for controlling the function of the user data decoder 13 in units of levels or caption information of user data stored in the memory 15 are read and transmitted to the video decoder 16 and displayed on the display screen. .

The video decoder 16 reconstructs and displays a moving image from compressed data, which is encoding, which is main data transmitted from the syntax parser 11. In addition, the decoding information or subtitle broadcast included in the user data is input from the host processor 12, and the configuration of each screen element is adjusted or changed for the display screen, or the screen size is adjusted.

In addition, the FIFO 14 temporarily stores the user data decoded by the user data decoder 13 in units of bytes. It is possible to efficiently arbitrate and adjust the memory access authority when the data is collected in a certain unit to access the memory 15 when there are several memory access blocks.

Here, the user data decoded by the user data decoder 13 has a start code value defined as shown in Table 1 below. The start code has 23 bits of '0' followed by '1'. It represents a 32-bit value consisting of a start code leading value consisting of a value and an 8-bit start code value.

The start of the user data indicates data until the next start code is detected from the byte data following the user data start code. In addition, user data should always be encoded in byte units.
Name Start Code Value (Hexadecimal) picture_start_code 00 slice_start_code 01-AF reserved B0 reserved B1 user_data_start_code B2 sequence_start_code B3 sequence_start_code B4 extension_error_code B5 reserved B6 sequenced B7 group_start_code B8 system start code B9-FF

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2 is a flowchart illustrating a method of decoding video user data of a digital TV according to the present invention.

First, when the digital TV is initialized, the host processor 12 sets the user data decoding mode (S11).

In this case, the user data decoding mode set by the host processor 12 may be decoded according to a user data level, decoded according to a selected identifier, identifier setting, a location of a memory to store user data, or whether to insert a user data header. And the like.

When the user data decoding mode is set (S11), the start code is detected to check the user data start code to decode the user data (S12) to (S13).

If the result of the check (S13) or the user data start code, the user data start code is checked whether the input user data belongs to the set level according to the decoding level set in step S11 (S14). Inspect again (S12)

Subsequently, if the check result (S14), the input user data belongs to the set level, it is checked whether the selected identifier (S15).

The identifier check determines whether to decode the identifier separately and checks whether the identifier matches.

Here, most user data have different identifiers depending on the broadcast standard and the type of information to be inserted. In general, the identifier inserts a 32-bit specific bit after the user data start code.

For example, in the ATSC standard, a 32-bit identifier of 0x47413934 is inserted after a user data start code, and an identifier of 0x44544731 is inserted into an AFD (Active Format Descriptor) transmitted to control display information of the DVB standard.

Subsequently, if the check result (S15), if the selected identifier, the user data is decoded (S16), the decoded user data is collected in a FIFO in units of bytes (S17) and stored in the memory (S18).

The size of the FIFO is selected in units that can efficiently use the memory.

In operation S19, it is determined whether the stored sequence of the current user data is finished and whether to continue collecting the user data in the FIFO.

If the check result (S19), the last sequence user data, an interrupt is generated to inform the host that decoding is completed (S20), and if not the last sequence user data, the user data is continuously collected in the FIFO.

After the decoding is completed, the host checks the memory location where the user data is stored and the number of user data, and reads it from the memory to use the system for control.

As a means for preventing error and displaying characteristics of each user data in transferring the user data to the host processor, a header shown in Table 2 is inserted when the data is stored in the memory.

User data header Field width Description temporal count 8 bit  count value incremented by 1 for each user data user data level 2 bits  the level containing the user data  "00" Sequence level  "01" GOP level  "10" Picture level  "11" reserved picture coding type 3bits  It is valid for the user data included in the picture level.  "001"  I picture  "010"  Ppicture  "011"  Bpicture  "100"  Dpicture  other  reserved

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As shown in Table 2, a temporal counter is a sequentially increasing 8-bit count value inserted for the purpose of distinguishing between user data. If the host processor does not handle user data interrupts properly, determine the number of data that has a transfer error.

The user data level is information about the level of the video sequence in which the user data is transmitted. It is used when the host analyzes user data without setting the decoding mode to decoding according to the level.

In addition, a picture coding type is a value that is meaningful when the picture level is user data, and in the case of closed captioning, synchronization between each picture and the caption to be displayed is synchronized.

As described above, the present invention can decode user data to suit the needs of the host processor and selectively decode only necessary data, thereby reducing the memory for storing user data and allowing the host processor to efficiently manage and control the entire system. It can work.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.

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Claims (11)

A syntax parser for retrieving a video sequence received from a transmitting end and extracting a video signal and user data; A video decoder for reconstructing a moving picture from the video signal encoded compressed data extracted from the syntax parser; A user data decoder which decodes user data extracted by the syntax parser; A FIFO for temporarily storing user data decoded by the user data decoder; A memory for collecting and storing data stored in the FIFO in predetermined units; When the user data decoding mode is set during initialization, and a start code is detected from the user data input from the syntax parser, the user data decoding unit is configured to determine whether or not the setting mode is matched and to decode the user data if it is matched. And a host processor for controlling and checking a sequence of user data stored in the memory to selectively read specific user data when the last time. The method of claim 1, The host processor, Control the function of the user data decoder in units of levels; And subtitle information of the user data stored in the memory is transferred to the video decoder to be displayed on a display screen. The method of claim 1, The video decoder unit, Digital TV video user data decoding apparatus characterized in that for receiving the decoding information or subtitle broadcast included in the user data from the processor to adjust the configuration of each screen element or adjust the screen size for the display screen . The method of claim 1, The user data Digital user video user data decoding apparatus characterized by having a start code for distinguishing each data The method of claim 4, wherein Digital video video user data decoding apparatus characterized by dividing the data until the second start code is detected from the byte data after the first start code of the user data into one user data Initializing the digital TV to selectively set a user data decoding mode by the host processor; Detecting a start code when user data is input; If the start code is detected, determining whether the set mode is matched, and if the start code is matched, decoding the user data and temporarily storing the decoded user data in a FIFO in units of bytes; Storing user data of a predetermined size in the FIFO; And inspecting the sequence of user data stored in the memory to selectively read specific user data into a host processor when it is the last. The method of claim 6, The user data decoding mode is At least one of whether to decode according to a user data level, whether to decode according to a selected identifier, an identifier setting, a location of a memory in which to store user data, and whether to insert a user data header. User data decoding method. The method of claim 7, wherein The transmission level is And at least one of a sequence start code, a group start code, and a picture start code, which are levels at which user data can be transmitted, is separately detected when not belonging to a set level. The method of claim 6, And determining whether to continue the operation of collecting user data in the FIFO on a predetermined basis by examining the sequence of user data. The method of claim 6, The host processor checks the memory location and the number of user data in which the user data is stored, and reads it from the memory to use for system control. The method of claim 6, And storing the user data in the memory, further inserting and storing respective headers indicating error prevention and characteristics of each user data.

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