KR100988010B1 - Method and Apparatus for Coding and Decoding using Bit-Precision - Google Patents

Abstract

Disclosed are a method and apparatus for encoding / decoding using decision bits. According to an embodiment of the present invention, an adaptive determination bit calculator for calculating an adaptive determination bit and an adaptive bit string for each symbol; A decision bit calculator for calculating decision bits for each predetermined field; And an encoder which encodes input data using at least one of the adaptive determination bit and the determination bit according to a type of a target field. Accordingly, by encoding / decoding the image data using the decision bits calculated by a plurality of methods, the compression efficiency can be improved.

Decision bits, adaptive decision bits, macroblocks, encoding, decoding

Description

Method and apparatus for encoding / decoding using decision bits {Method and Apparatus for Coding and Decoding using Bit-Precision}

The present invention relates to an apparatus for encoding and decoding image data (hereinafter referred to as " decoding / decoding "), and more particularly, to an encoding / decoding method and apparatus for increasing compression efficiency of image data. It is about.

As the amount of data transmission per second over the Internet increases, the amount of multimedia data such as moving pictures and photos is increasing compared to the past when simple text data is being transmitted. Accordingly, the demand for image compression technology is also increasing.

In order to compress an image, an entropy coding process of transforming a bit string representing a symbol included in data into another form is required. Entropy coding methods include Huffman coding and Arithmetic coding. In particular, Huffman coding is used in many video compression codecs because it guarantees an adequate level of compression efficiency and decoding complexity. Arithmetic geometry coding is used in fields requiring high compression efficiency because of its high decoding complexity but relatively high compression efficiency.

Recently, with the advent of various mobile media devices using limited power and composed of low-performance hardware, an entropy coding method with low decoding complexity is required. However, there is a problem in that research on a method of reducing decoding complexity is insufficient compared to a method for increasing the compression efficiency of an image.

On the other hand, as a method for reducing decoding complexity, an entropy coding scheme using bit precision has recently been proposed. However, the coding scheme has a problem in that compression efficiency is lowered by additionally inserting one decision bit per VOP or macroblock into the bitstream.

An object of the present invention is to provide a method and apparatus for encoding / decoding using decision bits that can improve compression efficiency by encoding / decoding video data using decision bits selected by a plurality of methods.

An object of the present invention is to provide a method and apparatus for encoding / decoding using decision bits that can improve compression efficiency by encoding / decoding video data using different methods of calculating decision bits for each field.

According to one aspect of the present invention, there is provided an apparatus capable of encoding input data using one or more of an adaptive decision bit and a decision bit.

According to an embodiment of the present invention, an adaptive determination bit calculator for calculating an adaptive determination bit and an adaptive bit string for each symbol; A decision bit calculator for calculating decision bits for each predetermined field; And an encoder which encodes input data using at least one of the adaptive determination bit and the determination bit according to a type of a target field.

According to another aspect of the present invention, there is provided an apparatus capable of decoding a bitstream using one or more of an adaptive decision bit and a decision bit.

According to an embodiment of the present invention, an adaptive determination bit calculator for calculating an adaptive determination bit and an adaptive bit string for each symbol; A decision bit extraction unit for extracting a decision bit from a received bitstream for each predetermined field; And a decoder which decodes the bitstream using one or more of the adaptive determination bit and the determination bit according to a type of a target field.

According to another aspect of the present invention, there is provided a method capable of encoding input data using at least one of an adaptive decision bit and a decision bit, and a recording medium having recorded thereon a program for performing the method.

According to an embodiment of the present invention, the method includes: calculating an adaptive determination bit and an adaptive bit string for each symbol; Calculating a decision bit for each predetermined field; And encoding the input data using at least one of the decision bit and the adaptive decision bit according to the type of the target field.

According to another embodiment of the present invention, a program of instructions, which can be executed by a digital processing apparatus, is tangibly implemented to perform a method capable of encoding input data, and the program can be read by the digital processing apparatus. A recording medium having recorded thereon, the method comprising: calculating an adaptive determination bit and an adaptive bit string for each symbol; Calculating a decision bit for each predetermined field; And a recording medium on which a program for performing input encoding of the input data using at least one of the decision bit and the adaptive decision bit according to a type of a target field is recorded.

According to another aspect of the present invention, there is provided a method capable of decoding a bitstream using at least one of an adaptive decision bit and a decision bit, and a recording medium on which a program for executing the method is recorded.

According to an embodiment of the present invention, the method includes: calculating an adaptive determination bit and an adaptive bit string for each symbol; Extracting a decision bit from the bitstream for each predetermined field; And decoding the bitstream using at least one of the adaptive determination bit and the determination bit according to a type of a target field.

According to another embodiment of the present invention, a program of instructions that can be executed by a digital processing apparatus for performing a method of decoding a bitstream is tangibly embodied, and a record recording a program that can be read by the digital processing apparatus. A medium, comprising: calculating an adaptive decision bit and an adaptive bit string for each symbol; Extracting a decision bit from the bitstream for each predetermined field; And a recording medium on which a program for performing the step of decoding the bitstream using at least one of the adaptive determination bit and the determination bit according to the type of a target field may be provided.

The present invention has an effect of improving compression efficiency by encoding / decoding video data using decision bits or / and adaptive decision bits calculated by a plurality of methods.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for encoding / decoding using decision bits, which can improve compression efficiency by encoding / decoding video data using different methods of calculating decision bits for each field.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to an encoding technique using decision bits. More particularly, the present invention relates to a technique for encoding a symbol using decision bits or adaptive decision bits. First, for convenience of understanding and explanation, the concept of an encoding scheme using decision bits according to the present invention will be described, and then the decision bits and the adaptive decision bits will be described.

The encoding method according to the present invention specifies a decision bit for symbols of input data. At this time, the symbol is each word unit constituting the input data. The decision bit is a value representing the length of a unit bit string for encoding symbols using bits, which are binary codes. That is, when the decision bit is n, the input symbols are represented in binary using n unit bit strings and are encoded accordingly. For example, assume that the input symbols are {2, 1, 0, 4, 5, 3} and the decision bit is 2. A value that can be represented by two bits (ie, a unit bit string) may represent a value from 0 to 3. However, if the symbol is larger than 3, it is impossible to express it with two bits, and thus additionally allocate two more bits to represent a value larger than three. This will be described in more detail as follows. Symbol 2 is represented by '10' when the value is binarized as it is, symbol '1' is represented by '01' when binarized, and symbol '0' is represented by '00' when binarized. However, since the symbol '4' is larger than 3, which is the maximum value represented by 2 bits, the symbol '4' cannot be represented by only 2 bits of the unit bit string. Therefore, the maximum value that can be represented by the first two bit values is expressed as '11', and the insufficient value 1 is expressed as the additional unit bit string '01' to connect the two results. That is, the symbol '4' may be represented by '1101'. Similarly to symbol 4, symbol 5 is represented by '1110' by combining the maximum value 3 and the surplus value 2 using 2 bits. In the case of symbol 3, it can be represented by 2 bits, but in this case, it is indistinguishable from the case of expressing a value greater than 3, and thus additional 2 bits are added to represent '1100' when the surplus value is 0. do.

If the above-described encoding method using the decision bit is applied to the case where the data symbol is 0 to 9, it can be expressed as shown in Table 1 below.

symbol Decision bits
One Decision bits
2 Decision bits
3 Decision bits
4 Decision bits
5 0 0 00 000 0000 00000 One 10 01 001 0001 00001 2 100 10 010 0010 00010 3 1000 1100 011 0011 00011 4 10000 1101 100 0100 00100 5 100000 1110 101 0101 00101 6 1000000 111100 110 0110 00110 7 10000000 111101 111000 0111 00111 8 100000000 111110 111001 1000 01000 9 1000000000 11111100 111010 1001 01001

As shown in Table 1, the bit string in which the symbol is encoded varies according to the decision bit. Therefore, it is necessary to select which one of several types of decision bits to encode before performing the encoding process, and the encoding compression rate varies according to the selected decision bits.

According to the present invention, a separate decision bit (hereinafter referred to as an adaptive decision bit) for each symbol is calculated in addition to the decision bits illustrated in Table 1. Here, the adaptation determination bit represents the length of the unit bit string for encoding each symbol. Hereinafter, the adaptive decision bit will be described in detail.

According to an embodiment of the present invention, each symbol may be represented by a bit string (hereinafter, referred to as an 'adaptive bit string') encoded using the adaptive decision bit and the adaptive decision bit and inserted into the bitstream. Table 2 below illustrates the adaptation decision bit and the adaptation bit string for each symbol.

symbol Adaptive decision bits  Adaptive bit string 0 0 - One One - 2 2 - 3 3 00 4 3 01 5 3 10 6 3 11 7 4 000 8 4 001

The length of each adaptation bit string is determined by subtracting 1 from the adaptation decision bits. For example, if the adaptation determination bit is 3, the length of the adaptation bit string is determined to be 2 (ie, 2 bits). At this time, when the adaptation decision bit is 0 to 2, the symbol is represented by only the adaptation decision bit without using the adaptation bit string. Since the length of each adaptation bit string is one obtained by subtracting one from the adaptation determination bits, each adaptation determination bit may represent as many symbols as n squares of two (n is the adaptation determination bit minus one). For example, adaptation decision bit 3 may represent four symbols and adaptation decision bit 4 may represent eight symbols. If the adaptation decision bit is 3, 00, 01, 10, 11 match symbols 3-6, as illustrated in Table 2. If the adaptation decision bit is 4, 000, 001, 010, 011, 100, 101, 110, and 111 are matched with symbols 7 to 14, respectively. The above-described adaptive decision bit and the adaptive bit string are inserted into the bitstream and transmitted to the decoder. In this case, the adaptation determination bit may be inserted into the bitstream through a separate process. This will be described in detail later with reference to FIGS. 2 to 7.

According to the present invention, a decision bit to be encoded is selected from candidate decision bits using values of target symbols (symbols belonging to a target macroblock or a target VOP-Video Object Plane).

The method of calculating the decision bit according to the present invention will be described in detail as follows. First, symbols to be encoded in a predetermined unit (VOP, macro block, or block unit) are encoded by using candidate decision bits in a predetermined range (1 to n), and then a decision bit having the best compression efficiency is selected as a decision bit to be encoded. do. For example, assuming that encoding bits having a value of 1 to 3 are encoded in a VOP unit, all symbols included in the corresponding VOP are encoded using 1 to 3 candidate decision bits. At this time, if the capacity of the VOP encoded using the candidate decision bits 1 to 3 is 3, 2, and 1 [Mbyte], respectively, decision bit 3 is finally selected as the decision bit of the corresponding VOP. According to the present invention according to the above-described method it is possible to select and use the decision bit having the highest compression ratio.

1 is a block diagram of an encoding apparatus using decision bits according to an embodiment of the present invention.

Referring to FIG. 1, the encoding apparatus 100 using decision bits according to an exemplary embodiment may include an input unit 110, an adaptive determination bit calculator 120, a determination bit calculator 130, and an encoder 140. ).

The input unit 110 receives input data from the outside and extracts and outputs symbols to be encoded. In this case, the input unit 110 may output the classification information, which divides the extracted symbols into a VOP unit and a macroblock unit (or a block unit of a predetermined size) together with the symbol. In addition, the input unit 110 extracts and outputs field information from the input data. Here, the field information is information indicating the type (or type) of the field in the input data. That is, the input unit 210 outputs field information, division information, and symbols to the decision bit calculator 230 and the encoder 240.

At this time, the input data is mcbpc (Macroblock type & Coded block pattern for chorminance), cbpy (Coded block pattern for luminance), motion vector (mv-x, mv-y) and DCT (DCT-luma, DCT-chroma) fields It may include one or more of. Mcbpc, cbpy, motion vector, and DCT fields are fields used in the encoding / decoding process according to the MPEG standard. Since this is obvious to those skilled in the art, a detailed description thereof will be omitted.

The adaptation determination bit calculator 220 calculates an adaptation determination bit and an adaptation bit string for a specific symbol according to a request signal of the encoder 240, and outputs the adaptation determination bit to the encoder 240. Here, since the method for calculating the adaptive determination bit and the adaptive bit string has been described above with reference to Table 2, a detailed description thereof will be omitted.

Of course, when the adaptation determination bit calculator 220 stores the adaptation determination bit and the adaptation bit string for a specific symbol, a separate calculation process may be omitted. For example, when the adaptation determination bit and the adaptation bit string for a specific symbol are stored in advance, when the request signal corresponding to the specific symbol is input from the encoder 240, the adaptation determination bit calculator 220 may apply to the symbol. Correspondingly, the pre-stored adaptive determination bit and the adaptive bit string may be extracted and output to the encoder 240.

In addition, according to an implementation method of the encoding apparatus, the adaptive determination bit and the adaptive bit string corresponding to each symbol may be calculated in advance and stored in the encoder 240. In this case, the adaptive decision bit calculator 220 may be omitted in the encoding apparatus 100.

The decision bit calculator 230 divides the received symbols by a VOP (or macro block) unit, calculates a decision bit, and outputs the decision bit to the encoder 240. The detailed calculation process of the decision bit is as described above.

The encoder 240 encodes the symbol by using the adaptive decision bit or the decision bit received from the adaptive decision bit calculator 220 and / or the decision bit calculator 230. Also, the encoder 240 may encode symbols differently according to field information input through the input unit 210. That is, the encoder 240 may encode any symbol by selecting any one of a plurality of encoding processes according to the input field information. This will be described in detail with reference to FIGS. 2 to 6.

2 is a flowchart illustrating an encoding process using decision bits and adaptive decision bits for each field according to an embodiment of the present invention. Each step described below is performed in each component of the encoding apparatus according to an embodiment of the present invention, but will be collectively described as an encoding apparatus for the convenience of understanding and explanation.

In operation 210, the encoding apparatus 100 extracts field information from input data. As described above, the field information is information indicating the type (or type) of the field in the input data.

In step 215, the encoding apparatus 100 inserts the extracted field information into the bitstream according to the encoding method according to the present invention. For example, the encoding apparatus 100 may insert field information into the header portion of the bitstream.

In operation 220, the encoding apparatus 100 determines whether a field to be currently encoded (hereinafter, referred to as a 'target field' for convenience of understanding and description) is a DCT field using extracted field information.

If the target field is not the DCT field, in step 225, the encoding apparatus 100 calculates the adaptive determination bit and the determination bit and uses the same to perform encoding on a symbol of a field corresponding to the target field. This will be described in more detail with reference to FIG. 3 below. In the present specification, a field other than the DCT field may be, for example, an mcbpc, cbpy, or motion vector field.

However, if the target field is a DCT field, in step 230, the encoding apparatus 100 calculates an adaptation determination bit corresponding to a symbol of the DCT field, and performs encoding on the symbol of the target field using this. This will be described in more detail with reference to FIG. 4 below.

3 is a flowchart illustrating an encoding process using decision bits and adaptive decision bits according to an embodiment of the present invention. Hereinafter, a method of encoding input data using an adaptive decision bit and a decision bit when the target field is not a DCT field will be described in detail. The following description is a flowchart illustrating a detailed description of one embodiment of step 225 of FIG. Each step described below is performed in each component of the encoding apparatus 100, but will be collectively described as an encoding apparatus for the convenience of understanding and explanation. In the following description, a method of classifying or extracting data in units of VOP from input data is obvious to those skilled in the art, and thus description thereof will be omitted. The encoding method described below may be used to encode symbols of mcbpc, cbpy or motion vector field.

First, the encoding apparatus 100 calculates the determination bit of the VOP (305). At this time, the decision bit is calculated for the index of the Huffman table of each field. For example, the encoding apparatus 100 may calculate decision bits using probability information of the VLC table of the MPEG standard. Here, the Huffman table is a table used in the Huffman coding scheme and lists the bit strings to be encoded according to the frequency of symbols to be encoded. Huffman table is obvious to those skilled in the art, detailed description thereof will be omitted.

In step 310, the encoding apparatus 100 sets the calculated decision bit as a temporary decision bit and inserts it into the bitstream. Hereinafter, the temporary decision bit herein is another term for the adaptive decision bit. It is therefore natural in the description of the present invention that the temporary decision bit should be interpreted and / or understood as an adaptive decision bit.

In this specification, the temporary decision bit is defined as a variable that stores the decision bit. The temporary decision bit is used for encoding in the following process.

In operation 315, the encoding apparatus 100 calculates determination bits for symbols of the target macroblock, the upper macroblock, and the left macroblock, respectively.

In the present specification, the target macroblock refers to a macroblock in which an encoding process is currently performed, the upper macroblock refers to a macroblock located above the target macroblock, and the left macroblock refers to a macroblock located to the left of the target macroblock. Refers to.

In operation 320, the encoding apparatus 100 compares the decision bits of the left macroblock with the decision bits of the upper macroblock and determines whether they are the same.

Hereinafter, in the present specification, the decision bit of the macro block and the decision bit of the symbol of the macro block should be understood to have the same meaning.

If it is determined to be the same, in step 325, the encoding apparatus 100 determines whether the decision bit of the left macroblock and the decision bit of the target macroblock are the same.

If it is determined to be the same, in step 330, the encoding apparatus 100 inserts a first bit value (eg, '1') into the bitstream.

In operation 335, the encoding apparatus 100 sets the decision bit of the target macroblock as a temporary decision bit. The encoding apparatus 100 inserts the decision bits of the target macroblock into the bitstream (335).

If the determination result of step 325 is not the same, in step 340, the encoding apparatus 100 inserts a second bit value '0' in the bitstream.

If the determination result of step 320 is not the same, in step 345, the encoding apparatus 100 determines whether the decision bit of the left macro block and the decision bit of the target macro block is the same.

If it is determined to be the same, flow proceeds to step 340.

However, if it is determined that they are not the same, in step 350, the encoding apparatus 100 determines whether the decision bit of the upper macroblock and the decision bit of the target macroblock are the same.

If it is determined that they are not the same, in step 355, the encoding apparatus 100 inserts a third bit value (eg, '11') into the bitstream.

In operation 360, the encoding apparatus 100 sets the decision bit of the target macroblock as a temporary decision bit. The encoding apparatus 100 inserts the decision bits of the target macroblock into the bitstream.

However, if each decision bit is determined to be the same, in step 365, the encoding apparatus 100 inserts a fourth bit value (eg, '10') into the bitstream.

In operation 370, the encoding apparatus 100 determines whether the bit value of the temporary decision bit is greater than or equal to a threshold (eg, 3).

If it is greater than or equal to the threshold, in step 375, the encoding apparatus 100 encodes a symbol of the target macroblock using the temporary decision bit.

For example, the encoding apparatus 100 may consider the temporary decision bit as an adaptive decision bit, calculate an adaptive bit string corresponding to the temporary decision bit, and encode the corresponding symbol by using the temporary decision bit.

In operation 380, the encoding apparatus 100 inserts an encoded bit string (that is, an adaptive bit string) into the bitstream.

If the determination result of step 370 is less than the threshold value, the encoding apparatus 100 ends the encoding process of the target macroblock.

Although the above-described encoding process has been described as encoding symbols included in one macro block for clarity of the invention, the encoding apparatus repeats the steps 315 to 380 until all the symbols of each frame or VOP are encoded. Of course it can be done.

Hereinafter, a process of encoding the symbols of the DCT field will be described.

4 is a flowchart illustrating a process of encoding symbols of a DCT field using an adaptive decision bit according to an embodiment of the present invention. Below is a detailed flowchart of one embodiment of 230 of FIG. 2. Each step described below is performed by each internal component of the encoding device 100 according to the present invention, but will be collectively described as an encoding device for the convenience of understanding and explanation.

In operation 405, the encoding apparatus 100 calculates an adaptation determination bit for a target symbol. Here, the target symbol refers to a symbol for which current encoding is performed among symbols of the DCT field.

In operation 410, the encoding apparatus 100 inserts an adaptation decision bit into the bitstream corresponding to the target symbol.

In operation 415, the encoding apparatus 100 generates an adaptive bit string by encoding a target symbol by using the adaptive determination bit.

In operation 420, the encoding apparatus 100 inserts the generated adaptive bit stream (that is, the encoded target symbol) into the bitstream.

Although the above-described encoding process has been described as encoding one symbol for clarity of the invention, the encoding apparatus 100 may repeat the process of steps 410 to 420 until all the symbols of the frame or the VOP are encoded. Can be.

FIG. 5 is a flowchart illustrating a process of encoding using a decision bit and an adaptive decision bit for each field according to another embodiment of the present invention. Each step described below is performed by each internal component of the encoding device 100, but will be collectively described as an encoding device for the convenience of understanding and explanation.

In operation 510, the encoding apparatus 100 inserts field information into a bitstream (450).

For example, the encoding apparatus 100 may extract field information from the input data and insert the corresponding field information into the header portion of the bitstream. Therefore, the field information may be extracted and used in the process of decoding each symbol thereafter.

In operation 515, the encoding apparatus 100 may determine that a field currently encoded using the extracted field information (hereinafter, referred to as a “target field” for convenience of understanding and description) includes a DCT field, a motion vector field, and the like. Determine which of the fields. As described above, the field information may be information indicating the type (or type) of the corresponding field.

In the present specification, other fields except for the motion vector field and the DCT field will be referred to as other fields for the convenience of understanding and explanation. For example, the other fields may be mcbpc and cbpy fields.

If it is determined that the target field is the other field, in step 530, the encoding apparatus 100 calculates the adaptive determination bit and the determination bit corresponding to the target field, respectively. The encoding apparatus 100 may encode the symbol of the target field by using the calculated adaptive decision bit and the decision bit. Since the encoding of the symbol of the target field by using the adaptive determination bit and the determination bit is the same as the encoding of the symbol of the target macroblock of FIG. 3, a redundant description will be omitted.

However, if the target field is determined to be a motion vector field, in step 540, the encoding apparatus 100 calculates a decision bit for a symbol of the target field and encodes the symbol of the target field using the calculated decision bit. This will be described in more detail with reference to FIGS. 6 to 8 below.

However, if the target field is a DCT field, in step 550, the encoding apparatus 100 calculates an adaptation determination bit for a symbol of the target field. The encoding apparatus 100 encodes the symbol of the target field by using the calculated adaptive decision bit. Since this is the same as described above in FIG. 4, redundant descriptions will be omitted.

6 is a flowchart illustrating a process of encoding a symbol of a motion vector field using decision bits according to an embodiment of the present invention. This is a detailed flowchart of one embodiment of step 540 of FIG. Each step described below is performed by each internal component of the encoding device 100, but will be collectively described as an encoding device for the convenience of understanding and explanation.

In operation 610, the encoding apparatus 100 may determine an X-axis motion vector (hereinafter referred to as 'MV-X' for convenience of understanding and explanation) or a Y-axis motion vector (hereinafter for convenience of understanding and explanation). The decision bit for the target VOP in the field 'MV-Y' is calculated. For example, the encoding apparatus 100 may calculate decision bits for a symbol (ie, a motion vector) belonging to the target VOP, corresponding to the target VOP.

In operation 615, the encoding apparatus 100 inserts the calculated decision bits into the bitstream.

In operation 620, the encoding apparatus 100 encodes an absolute value of a motion vector that is currently encoded (hereinafter, referred to as a 'target motion vector' for convenience of understanding and description) using the calculated decision bits.

In operation 625, the encoding apparatus 100 inserts the encoded absolute value into the bitstream.

In operation 630, the encoding apparatus 100 determines whether the target motion vector is '0'.

If the target motion vector is 0, the encoding apparatus 100 ends the encoding of the target motion vector.

However, if the target motion vector is not '0', in step 635, the encoding apparatus 100 inserts the bit value of the sine bit of the target motion vector into the bitstream.

Although the above-described encoding process has been described as encoding symbols included in one macro block for clarity, the encoding apparatus may repeat steps 610 to 635 until all symbols of the frame or VOP are encoded. Can be.

7 is a flowchart illustrating a process of encoding a symbol of a motion vector field using decision bits according to another embodiment of the present invention. This is a detailed flowchart of another embodiment of step 540 of FIG. Each step described below is performed by each internal component of the encoding device 100, but will be collectively described as an encoding device for the convenience of understanding and explanation.

In operation 710, the encoding apparatus 100 calculates a decision bit for the target VOP of the motion vector (MV-X or MV-Y) field. At this time, the decision bit is calculated for a value excluding a sign of a symbol (that is, a motion vector) belonging to the index or VOP of the Huffman table of each field and a value less than or equal to the decimal point.

In operation 715, the encoding apparatus 100 inserts the calculated decision bits into the bitstream.

In operation 720, the encoding apparatus 100 calculates an absolute value by removing a value below the decimal point of the target symbol (that is, the target motion vector).

In operation 725, the encoding apparatus 100 encodes the calculated absolute value using the calculated determination bits.

In operation 730, the encoding apparatus 100 inserts the encoded absolute value into the bitstream.

In operation 735, the encoding apparatus 100 determines whether the calculated absolute value is zero.

If the calculated absolute value is '0', the encoding apparatus 100 indicates that there are no values below the sign and the decimal point corresponding to the target symbol, and thus ends the encoding process corresponding to the target symbol.

However, if the calculated absolute value is not '0', in step 740, the encoding apparatus 100 inserts a sine bit of the target symbol into the bitstream. Here, the sine bit is a bit value indicating the sign of the target symbol. For example, the sign bit may be '0' if the target symbol is negative, and the sign bit may be '1' if it is positive.

In operation 745, the encoding apparatus 100 inserts a value after the decimal point removed corresponding to the target symbol (that is, the target motion vector) into the bitstream.

Although the above-described encoding process has been described as encoding symbols included in one macro block for clarity, the encoding apparatus may repeat steps 710 to 745 until all symbols of the corresponding frame or VOP are encoded. Can be.

8 is a flowchart illustrating a process of encoding a symbol of a motion vector field using decision bits according to another embodiment of the present invention. Each step described below is a detailed flowchart of yet another embodiment of 540 of FIG. 5. Each step described below is performed by each internal component of the encoding apparatus 100, but will be collectively described as the encoding apparatus 100 for the convenience of understanding and explanation.

In operation 810, the encoding apparatus 100 calculates a decision bit for the target VOP of the motion vector (MV-X or MV-Y) field. At this time, the decision bit is calculated for a value excluding a sign of a symbol (that is, a motion vector) belonging to the index or VOP of the Huffman table of each field and a value less than or equal to the decimal point.

In operation 815, the encoding apparatus 100 inserts the calculated decision bit into the bitstream.

In operation 820, the encoding apparatus 100 calculates an absolute value of the target motion vector, and then determines whether the absolute value of the target motion vector is equal to or less than a threshold (eg, '3').

If the absolute value of the target motion vector is less than or equal to the threshold, in step 825, the encoding apparatus 100 encodes the absolute value of the target motion vector using the calculated decision bits.

In operation 830, the encoding apparatus 100 inserts an encoded bit string (that is, an encoded absolute value) into the bitstream.

In operation 835, the encoding apparatus 100 determines whether the absolute value of the target motion vector is '0'.

If the absolute value of the target motion vector is '0', the encoding apparatus 100 recognizes that the target motion vector does not include a sign and a value below the decimal point, and ends the encoding process of the target motion vector.

However, if the absolute value of the target motion vector is not '0', in step 840, the encoding apparatus 100 inserts a sine bit of the target motion vector into the bitstream. At this time, the sine bit is a bit value indicating the sign of the motion vector.

If the absolute value of the target motion vector exceeds the threshold as a result of the determination in step 820, the encoding apparatus 100 calculates the absolute value after removing the decimal point of the target motion vector in step 845.

In operation 850, the encoding apparatus 100 encodes the calculated absolute value using the decision bit.

In operation 855, the encoding apparatus 100 inserts an encoded bit string (that is, an absolute value calculated by removing a decimal point) into the bitstream.

In operation 860, the encoding apparatus 100 determines whether an absolute value calculated corresponding to the target motion vector is '0'.

If the calculated absolute value is '0', the encoding apparatus 100 recognizes that the target motion vector does not include a sign and a value below the decimal point, and ends the encoding process of the target motion vector.

However, if the calculated absolute value is not '0', in step 865, the encoding apparatus 100 inserts a sine bit of the target motion vector into the bitstream.

In operation 870, the encoding apparatus 100 inserts a value below the decimal point of the target motion vector into the bitstream.

Although the above-described encoding process has been described as encoding symbols included in one macroblock for clarity, the encoding apparatus repeats the processes of steps 810 to 870 until all the symbols of the frame or the VOP are encoded. Can be done.

9 is a block diagram of a decoding apparatus using decision bits according to an embodiment of the present invention.

9, a decoding apparatus 900 according to an embodiment of the present invention includes an input unit 910, an adaptive decision bit calculator 920, a decision bit extractor 930, and a decoder 940. .

The input unit 810 receives the encoded bitstream, extracts field information and encoded data of each field according to a predetermined format, and outputs the extracted bit information to the decision bit extractor 930 and the decoder 940.

The adaptive decision bit calculator 820 calculates an adaptive decision bit and an adaptive bit string corresponding to a specific field according to the request signal of the decoder 840, and then calculates a symbol corresponding to the calculated adaptive decision bit and the adaptive bit string. And output to the decoder 940. Here, since the method for calculating the adaptive determination bit and the adaptive bit string has been described above with reference to Table 2, redundant descriptions thereof will be omitted. Of course, the adaptive decision bit calculator 820 may extract the adaptive decision bits from the bitstream.

In addition, when the adaptive determination bit, the adaptive bit string and the symbol are stored in advance, the adaptive determination bit calculator 920 extracts the corresponding adaptive determination bit, the adaptive bit string and the symbol according to the request signal of the decoder 940. The output may be output to the decoder 940. Of course, according to an implementation method, when the adaptive determination bit, the adaptive bit string, and the symbol are stored in the decoder 940, the adaptive determination bit calculator 920 may be excluded from the decoding apparatus 900. Do.

The decision bit extractor 930 extracts a decision bit from the received encoded bitstream and outputs the decision bit to the decoder 940. Also, the decision bit extractor 930 may calculate the decision bit using the received encoded bitstream.

For example, the decision bit of the upper macro block and the decision bit of the left macro block corresponding to the target macro block are calculated through the encoded bitstream. Here, since the method for calculating the determination bit is the same as described above using Table 1, a separate description thereof will be omitted.

The decoder 940 decodes the encoded bitstream input from the input unit 910 using the adaptive decision bit or the decision bit. The decoder 940 may decode the bitstream encoded differently according to the field information received from the input unit 910. This will be described in detail with reference to the accompanying drawings below.

10 is a flowchart illustrating a process of decoding using a decision bit and an adaptive decision bit for each field according to an embodiment of the present invention. Hereinafter, a method for decoding a bitstream encoded by the encoding method described with reference to FIG. 2 will be described. Each step described below is performed by each internal component of the decoding apparatus 900, but will be collectively described as a decoding apparatus for the convenience of understanding and explanation.

In operation 1010, the decoding apparatus 900 extracts field information from the received encoded bitstream.

In operation 1015, the decoding apparatus 900 determines whether a field for decoding by using the extracted field information (hereinafter referred to as a 'target field' for convenience of understanding and explanation) is a DCT field. .

In the present specification, other fields other than the DCT field will be collectively referred to as other fields. The other fields may be, for example, mcbpc, cbpy, motion vector fields.

If the target field is not the DCT field, in operation 1020, the decoding apparatus 900 performs decoding corresponding to the target field by using the adaptive determination bit and the determination bit. This will be described in more detail with reference to the accompanying drawings below.

However, if the target field is a DCT field, in step 1025, the decoding apparatus 900 decodes the bitstream coded corresponding to the target field into symbols by using the adaptive decision bit. This will be described in more detail with reference to the accompanying drawings below.

11 is a flowchart illustrating a decoding process using decision bits and adaptive decision bits according to an embodiment of the present invention. 11 is a flowchart illustrating an embodiment of step 1020 of FIG. 10 in detail. 11 is a description of a method for decoding a bitstream encoded by the method described above with reference to FIG. 3. In addition, each step described below is performed by each internal functional component of the decoding device 900, but will be collectively described as a decoding device for the convenience of understanding and explanation.

In operation 1110, the decoding apparatus 900 extracts a determination bit corresponding to the VOP from the received encoded bitstream.

In operation 1115, the decoding apparatus 900 calculates determination bits of the upper macro block and the left macro block, respectively.

In operation 1120, the decoding apparatus 900 determines whether the calculated decision bit of the left macroblock and the decision bit of the upper macroblock are the same.

If the decision bit of the left macro block and the decision bit of the upper macro block are the same, the decoding apparatus 900 extracts one bit (1 bit) from the encoded bitstream in step 1125.

In operation 1130, the decoding apparatus 900 determines whether the extracted one bit value is a fifth bit value (eg, '1').

If it is the fifth bit value, in step 1135, the decoding apparatus 900 extracts the decision bit from the encoded bitstream, and sets the extracted decision bit as a temporary decision bit. As described above, it is natural that the temporary decision bit should be understood and interpreted as an adaptation decision bit in another representation that refers to the adaptation decision bit.

However, if it is not the fifth bit value, in step 1140, the decoding apparatus 900 sets the calculated decision bit of the upper macroblock as a temporary decision bit.

If the determination bit of the left macroblock is different from the determination bit of the upper macroblock as a result of the determination in step 1120, the decoding apparatus 900 extracts one bit from the encoded bitstream in step 1145.

In operation 1150, the decoding apparatus 900 determines whether the extracted one bit value is a sixth bit value (eg, '0').

If the sixth bit value, the decoding apparatus 900 in step 1155 sets the decision bit of the left macro block to a temporary decision bit.

However, if it is not the sixth bit value, in operation 1160, the decoding apparatus 900 extracts one bit from the encoded bitstream.

Subsequently, at 1165, the decoding apparatus 900 determines whether the extracted 1 bit is a seventh bit value (eg, '0').

If it is not the seventh bit value, in step 1170, the decoding apparatus 900 extracts the decision bit from the encoded bitstream, and sets the extracted decision bit as a temporary decision bit.

However, if it is the seventh bit value, the decoding apparatus 900 sets the decision bit of the upper macroblock as a temporary decision bit in step 1175.

In operation 1180, the decoding apparatus 900 determines whether the bit value of the temporary decision bit is greater than or equal to a threshold (eg, '3').

If the temporary decision bit is greater than or equal to the threshold, the decoding apparatus 900 decodes the symbol of the target macroblock using the temporary decision bit in step 1185.

For example, the decoding apparatus 900 may calculate an adaptive bit string corresponding to the same adaptive decision bit as the temporary decision bit. The corresponding bit string may be decoded with a symbol corresponding to the calculated adaptive bit string.

However, if the temporary decision bit is less than the threshold, the decoding apparatus 900 terminates the process of decoding the symbol of the target macroblock.

Although the above-described encoding process has been described as decoding symbols included in one macro block for clarity, the encoding apparatus may repeat steps 1110 to 1180 until all symbols of the frame or VOP are decoded. Can be. In addition, the decoding process according to an embodiment of the present invention is a process for decoding the encoded bitstream in a manner suitable for encoding the symbols of the mcbpc, cbpy, MV-x, and MV-y fields. According to the present invention, the symbol of the DCT field may increase the compression efficiency through a separate encoding process. Therefore, a separate process of decoding the symbols of the DCT field is needed. Hereinafter, a process of encoding the symbols of the DCT field will be described.

12 is a flowchart illustrating a process of decoding symbols of a DCT field using an adaptation decision bit according to an embodiment of the present invention. 12 is a flowchart illustrating an embodiment of 1025 of FIG. 10 in detail. 12 is a description of a method for decoding a bitstream encoded by the method of FIG. Each step described below is performed by each internal component of the decoding device 900, but will be collectively referred to as a decoding device for the convenience of understanding and explanation.

In operation 1210, the decoding apparatus 900 extracts an adaptive determination bit from the received encoded bitstream.

In operation 1215, the decoding apparatus 900 extracts an encoded bit string (that is, an adaptive bit string) from the encoded bit stream.

In operation 1220, the decoding apparatus 900 decodes the adaptive bit string into symbols using the adaptive determination bit (1015).

Although the above-described decoding process has been described as decoding one symbol for clarity of the invention, the decoding apparatus 900 may repeat steps 1210 to 1220 until all the symbols of the frame or the VOP are decoded. .

13 is a flowchart illustrating a process of decoding using a decision bit and an adaptive decision bit for each field according to another embodiment of the present invention. Each step described below is performed by each internal component of the decoding device 900, but will be collectively referred to as a decoding device for the convenience of understanding and explanation.

In operation 1310, the decoding apparatus 900 extracts field information from the received encoded bitstream. As described above, the field information may be information indicating the type (or type) of the corresponding field.

In operation 1315, the decoding apparatus 900 uses the extracted field information as a field for performing current decoding (hereinafter, referred to as a 'target field' for convenience of understanding and explanation) as a DCT field and a motion vector field. And any other field.

For example, the other field refers to the remaining fields except for the DCT field and the motion vector field. For example, the other fields may be mcbpc and cbpy fields.

If the target field is another field, in operation 1320, the decoding apparatus 900 extracts an adaptive decision bit and a decision bit from the encoded bitstream, and then uses the corresponding adaptive decision bit and the decision bit to encode an encoded bit string corresponding to the target field. Extract and decode Since the decoding process is the same as described above with reference to FIG. 11, duplicate description thereof will be omitted.

However, if the target field is a motion vector field, in operation 1325, the decoding apparatus 900 extracts a decision bit corresponding to the target field, and decodes a bit string corresponding to the target field using the extracted determination bit.

However, if the target field is a DCT field, in operation 1330, the decoding apparatus 900 extracts an adaptive determination bit corresponding to the target field and decodes an encoded bit string corresponding to the target field using the extracted adaptive determination bit. . The decoding of the data encoded using the adaptive decision bit into the symbols of the DCT field is the same as the decoding process described above with reference to FIG. 12, and thus a detailed description thereof will be omitted.

14 is a flowchart illustrating a process of decoding data encoded using decision bits into a symbol of a motion vector field according to an embodiment of the present invention. 14 is a detailed flowchart of one embodiment of step 1325 of FIG. 13. FIG. 14 is a diagram for describing a method of decoding a bitstream encoded using the decision bit described with reference to FIG. 6. Each step described below is performed by each internal component of the decoding apparatus 900, but will be collectively described as a decoding apparatus for the convenience of understanding and explanation.

In operation 1410, the decoding apparatus 900 extracts a decision bit from the received encoded bitstream.

In operation 1415, the decoding apparatus 900 extracts an encoded bit string corresponding to the decision bit extracted from the encoded bitstream.

In operation 1420, the decoding apparatus 900 decodes the extracted bit string using the extracted determination bits. Here, the decoded bit string may be a symbol (ie, an absolute value of a motion vector).

In operation 1425, the decoding apparatus 900 determines whether the decoded bit string is '0'.

If the decoded bit string is '0', the decoding apparatus 900 ends the decoding process corresponding to the corresponding bit string.

However, if the decoded bit string is not '0', the decoding apparatus 900 extracts a sine bit from the encoded bitstream in step 1430, and attaches a sine bit to the decoded bit stream to form a final symbol (ie, a motion vector). Decrypt

Although the above-described encoding process has been described as decoding symbols included in one macro block for clarity, the decoding apparatus 900 performs steps 1410 to 1430 until all the symbols of the frame or the VOP are decoded. Can be repeated.

15 is a flowchart illustrating a process of decoding a coded bitstream using decision bits according to another embodiment of the present invention. 15 is a detailed flow chart according to another embodiment of step 1325 of FIG. 15 is a description of a method of decoding a bitstream encoded by the method described above with reference to FIG. 7. In addition, each step described below is performed by each internal component of the decoding device 900, but will be collectively described as a decoding device for the convenience of understanding and explanation. In the following description, it is assumed that the symbols included in one macroblock are decoded.

In operation 1510, the decoding apparatus 900 extracts the decision bit from the encoded bitstream.

In operation 1515, the decoding apparatus 900 extracts an encoded bit string from the encoded bit stream.

In operation 1520, the decoding apparatus 900 decodes the extracted bit string using the extracted determination bits. Here, the decoded bit string may be an absolute value of a motion vector with a decimal point removed.

In operation 1525, the decoding apparatus 900 determines whether the value of the decoded bit string is '0'.

If the value of the decoded bit string is '0', the decoding apparatus 900 determines the decoded bit string as a symbol (ie, a motion vector) and ends the decoding process. For example, if the value of the decoded bit string is '0', the decoding apparatus 900 recognizes that the motion vector does not include a sign or a value below the decimal point and uses the decoded bit string as a symbol (ie, a motion vector). You can output and end the decoding process.

However, if the value of the decoded bit string is not '0', the decoding apparatus 900 extracts a sine bit from the coded bitstream in step 1530.

In operation 1535, the decoding apparatus 900 extracts a bit string below the decimal point from the encoded bitstream.

In operation 1540, the decoding apparatus 900 reconstructs a symbol (ie, a motion vector) by adding a bit string having a decimal point or less to the decoded bit string and attaching a sign corresponding to a sine bit.

Although the above-described decoding process has been described as decoding the symbols included in one macro block for clarity, the decoding apparatus 900 performs steps 1510 to 1540 until all the symbols of the frame or the VOP are decoded. Can be repeated.

16 is a flowchart illustrating a process of decoding a determined bitstream into a symbol according to another embodiment of the present invention. 16 is a detailed flow chart according to another embodiment of 1325 of FIG. 13. Hereinafter, FIG. 16 will be described in detail with respect to a method of decoding a bitstream encoded by the method described with reference to FIG. 8. In addition, each step described below is performed by each internal component of the decoding device 900, but will be collectively described as a decoding device for the convenience of understanding and explanation.

In operation 1610, the decoding apparatus 900 extracts a decision bit from the received encoded bitstream.

In operation 1615, the decoding apparatus 900 extracts an encoded bit string from the encoded bitstream.

In operation 1620, the decoding apparatus 900 decodes the encoded bit string using the extracted determination bits. Here, the decoded bit string may be an absolute value of a motion vector from which a value below the decimal point is removed.

In operation 1625, the decoding apparatus 900 determines whether the value of the decoded bit string is '3' or less.

If the value of the decoded bit string is equal to or less than '3', in operation 1630, the decoding apparatus 900 determines whether the value of the decoded bit string is '0'.

If the value of the decoded bit string is '0', the decoding apparatus 900 determines that the decoded bit string is a motion vector that does not include a sign and a value less than or equal to the decimal point, and thus decodes the decoded bit string. ) And ends the decoding process for the corresponding decoded bit string.

However, if the value of the decoded bit string is not '0', the decoding apparatus 900 extracts a sine bit from the coded bitstream in step 1635. The decoding apparatus 900 restores a symbol (ie, a motion vector) by attaching the extracted sine bits to the decoded bit string.

If the value of the decoded bit string is not '3' or less as a result of the determination in step 1625, the decoding apparatus 900 determines whether the value of the decoded bit string is '0' in step 1640.

If the value of the decoded bit string is '0', the decoding apparatus 900 restores the decoded bit string as a symbol (ie, a motion vector), and ends the decoding process on the decoded bit string.

However, if the value of the decoded bit string is not '0', the decoding apparatus 900 extracts a sine bit from the coded bitstream in step 1645.

In operation 1650, the decoding apparatus 900 extracts a bit string representing a value below the decimal point from the encoded bitstream.

In operation 1655, the decoding apparatus 900 reconstructs a symbol (ie, a motion vector) by adding a value corresponding to the extracted decimal point to the decoded bit string and attaching a sign corresponding to the extracted sine bit.

Although the above-described decoding process has been described as decoding symbols included in one macro block for clarity, the decoding apparatus 900 performs steps 1610 to 1655 until all symbols of the frame or VOP are decoded. Can be repeated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a block diagram of an encoding apparatus using decision bits according to an embodiment of the present invention.

2 is a flowchart illustrating an encoding process using decision bits and adaptive decision bits for each field according to an embodiment of the present invention.

3 is a flowchart illustrating an encoding process using decision bits and adaptive decision bits according to an embodiment of the present invention.

4 is a flowchart illustrating a process of encoding symbols of a DCT field using an adaptive decision bit according to an embodiment of the present invention.

5 is a flowchart illustrating an encoding process using decision bits and adaptive decision bits for each field according to another embodiment of the present invention.

6 is a flowchart illustrating a process of encoding a symbol of a motion vector field using decision bits according to an embodiment of the present invention.

7 is a flowchart illustrating a process of encoding a symbol of a motion vector field using decision bits according to another embodiment of the present invention.

8 is a flowchart illustrating a process of encoding a symbol of a motion vector field using decision bits according to another embodiment of the present invention.

9 is a block diagram of a decoding apparatus using decision bits according to an embodiment of the present invention.

10 is a flowchart illustrating a process of decoding using a decision bit and an adaptive decision bit for each field according to an embodiment of the present invention.

11 is a flowchart illustrating a decoding process using decision bits and adaptive decision bits according to an embodiment of the present invention.

12 is a flowchart illustrating a process of decoding symbols of a DCT field using an adaptive decision bit according to an embodiment of the present invention.

13 is a flowchart illustrating a process of decoding using a decision bit and an adaptive decision bit for each field according to another embodiment of the present invention.

14 is a flowchart illustrating a process of decoding data encoded using decision bits into a symbol of a motion vector field, according to an embodiment of the present invention.

15 is a flowchart illustrating a process of decoding data encoded using decision bits into a symbol of a motion vector field according to another embodiment of the present invention.

16 is a flowchart illustrating a process of decoding data encoded using decision bits into a symbol of a motion vector field according to another embodiment of the present invention.

Claims (38)

An adaptive determination bit calculator configured to calculate an adaptive determination bit and an adaptive bit string for each symbol; A decision bit calculator for calculating decision bits for each predetermined field; And An encoder which encodes input data using at least one of the adaptive determination bit and the determination bit according to a type of a target field, The determination bit is a bit representing a length of a unit bit string for encoding the input data, And the adaptive determination bit is a bit indicating a length of a unit bit string having an optimal coding efficiency corresponding to the symbol among the lengths of the unit bit strings. According to claim 1, And the adaptive bit string is a bit string obtained by encoding the input data using the adaptive determination bit. According to claim 1, The decision bit calculator is The encoding device characterized in that the decision bit having the highest compression efficiency among the predetermined candidate decision bits (1 to n) is selected as the decision bit. According to claim 1, The adaptive decision bit calculator is The encoding device characterized in that the decision bit having the highest compression efficiency among the predetermined candidate decision bits (1 to n) is selected as the adaptive decision bit. According to claim 1, The encoder, And when the target field is an mcbpc field or a cbpy field, encoding the input data using the adaptive decision bit and the decision bit. According to claim 1, The encoder, And encoding the input data by using the adaptive decision bit when the target field is a DCT field. The method of claim 1, The encoder, If the target field is a motion vector field, the absolute value of the motion vector field data among the input data is encoded using the determination bit, And a sign bit representing a sign of the motion vector field data, into a bitstream. According to claim 1, The encoder, When the target field is a motion vector field, a truncation value of an absolute value of motion vector field data among the input data is encoded using the determination bit, Inserting a sine bit and a value below the decimal point indicating a sign of the motion vector field data into a bitstream, And the truncation value is a value obtained by truncating a decimal point below the absolute value. The method of claim 1, The encoder, When the target field is a motion vector field, the absolute value or the truncated value of the absolute value is encoded using the determination bit according to an absolute value of the motion vector field data among the input data. At least one of a sine bit representing a sign of the motion vector field data and a value below a decimal point is inserted into a bitstream, And the truncation value is a value obtained by truncating a decimal point below the absolute value. According to claim 1, The encoder, If the target field is another field, an adaptive decision bit equal to the decision bit of the target macroblock or the decision bit of the VOP is determined according to whether the decision bit corresponding to the target macroblock, the upper macroblock and the left macroblock is the same. And encoding the input data by using the encoding device. Calculating an adaptive determination bit and an adaptive bit string for each symbol; Calculating a decision bit for each predetermined field; And Encoding input data using at least one of the determination bit and the adaptive determination bit according to a type of a target field; The determination bit is a bit representing a length of a unit bit string for encoding the input data, And the adaptation determination bit is a bit indicating a length of a unit bit string having an optimal coding efficiency corresponding to the symbol among the lengths of the unit bit strings. 12. The method of claim 11, And the adaptive bit string is a bit string obtained by encoding the input data using the adaptive determination bit. 12. The method of claim 11, Computing the decision bit, An encoding method characterized in that the decision bit having the highest compression efficiency among the predetermined candidate decision bits (1 to n) is selected as the decision bit. 12. The method of claim 11, Computing the adaptation decision bit, An encoding method characterized in that the decision bit having the highest compression efficiency among the predetermined candidate decision bits (1 to n) is selected as the decision bit. 12. The method of claim 11, Encoding the input data, And encoding the input data using the adaptive determination bit and the determination bit when the target field is an mcbpc or cbpy field. 12. The method of claim 11, Encoding the input data, If the target field is a DCT field, encoding the data of the DCT field among the input data by using the adaptive determination bit; 12. The method of claim 11, Encoding the input data, If the target field is a motion vector field, encoding an absolute value of motion vector field data among the input data by using the determination bit; And And inserting a sine bit representing a sign of the motion vector field data into a bitstream. 12. The method of claim 11, Encoding the input data, If the target field is a motion vector field, encoding a truncated value of an absolute value of motion vector field data among the input data using the determination bit; And Inserting a sign bit representing a sign of the motion vector field data and a value below a decimal point into a bitstream, And the truncation value is a value obtained by truncating the absolute value to a value less than or equal to the decimal point. 12. The method of claim 11, Encoding the input data, If the target field is a motion vector field, encoding the absolute value or the truncated value of the absolute value using the determination bit according to an absolute value of the motion vector field data among the input data; And Inserting at least one of a sine bit representing a sign of the motion vector field data and a value below a decimal point into a bitstream, And the truncation value is a value obtained by truncating the absolute value to a value less than or equal to the decimal point. 12. The method of claim 11, Encoding the input data, If the target field is any one of an mcbpc field, a cbpy field, and a motion vector field, Determining whether the determination bits corresponding to the target macroblock, the upper macroblock, and the left macroblock are the same; And And encoding the input data using the decision bit of the target macroblock or the decision bit of the VOP according to the same. In the recording medium on which a program of instructions that can be executed by a digital processing apparatus is tangibly implemented to perform a method capable of encoding input data. Calculating an adaptive determination bit and an adaptive bit string for each symbol; Calculating a decision bit for each predetermined field; And Encoding input data using at least one of the determination bit and the adaptive determination bit according to a type of a target field; The determination bit is a bit representing a length of a unit bit string for encoding the input data, And the adaptation determination bit is a bit indicating a length of a unit bit string having an optimal coding efficiency corresponding to the symbol among the lengths of the unit bit strings. An adaptive determination bit calculator configured to calculate an adaptive determination bit and an adaptive bit string for each symbol; A decision bit extraction unit for extracting a decision bit from a received bitstream for each predetermined field; And A decoder which decodes the bitstream using at least one of the adaptive determination bit and the determination bit according to a type of a target field, The determination bit is a bit representing a length of a unit bit string for encoding the input data, And the adaptation determination bit is a bit representing a length of a unit bit string having an optimal coding efficiency corresponding to the symbol among the lengths of the unit bit strings. 23. The method of claim 22, And the adaptive bit string is a bit string obtained by encoding the input data by decoding the bit stream using the adaptive determination bit. 23. The method of claim 22, Further comprising an input unit for extracting field information from the bitstream, The decoder decodes the bitstream differently according to the field information. And the field information is information indicating a type of each field included in the bitstream. 23. The method of claim 22, The decoding unit, If the target field is any one of an mcbpc field, a cbpy field, and a motion vector field, Bitstream using an adaptive decision bit equal to one of a decision bit for a VOP, a decision bit for an upper macroblock, or a decision bit for a left macroblock, depending on whether the decision bit corresponding to an upper macroblock and a left macroblock is the same. Decoding apparatus characterized in that for decoding. 23. The method of claim 22, The decoding unit And if the target field is a DCT field, decoding a bit string of a DCT field in the bitstream using an adaptive determination bit. 23. The method of claim 22, The decoding unit When the target field is a motion vector field, the bit string for the motion vector field in the bitstream is decoded into an absolute value of the motion vector using the determination bit.  And extracting a sine bit from the bitstream and restoring a motion vector by adding a sign corresponding to the extracted sine bit to an absolute value of the motion vector. 23. The method of claim 22, The decoding unit When the target field is a motion vector field, the bit string for the motion vector field in the bitstream is decoded using the decision bit. A value below the decimal point is added to the value of the decoded bit string to calculate an absolute value of the motion vector, Restoring the motion vector by attaching the sign according to the sine bit to the absolute value of the motion vector, And a value less than the decimal point and the sign bit are extracted from a bitstream. 23. The method of claim 22, The decoding unit When the target field is a motion vector field, decoding a bit string corresponding to the motion vector field in the bitstream using the determination bit; Calculating an absolute value of a motion vector using at least one of the decoded bit string and a value below a decimal point according to an analysis result of the decoded bit string, A motion vector is calculated by attaching a sign corresponding to a sine bit to an absolute value of the calculated motion vector, And a value less than the decimal point and the sign bit are extracted from a bitstream. Calculating an adaptive determination bit and an adaptive bit string for each symbol; Extracting a decision bit from the bitstream for each predetermined field; And Decoding the bitstream using at least one of the adaptive determination bit and the determination bit according to a type of a target field; The determination bit is a bit representing a length of a unit bit string for encoding the input data, And the adaptation determination bit is a bit indicating a length of a unit bit string having an optimal coding efficiency corresponding to the symbol among the lengths of the unit bit strings. The method of claim 30, And the adaptive bit string is a bit string obtained by encoding input data using the adaptive determination bit. The method of claim 30, Decoding the bitstream, Extracting field information from the bitstream; Decoding the bitstream differently according to the field information; And the field information indicates a field to which encoded data belongs. The method of claim 30, Decoding the bitstream, If the target field is any one of an mcbpc field, a cbpy field, and a motion vector field, Calculating whether the decision bit corresponding to an upper macro block and a left macro block are the same; And And decoding the bitstream using any one of a decision bit for a VOP, a decision bit of an upper macroblock, and a decision bit of a left macroblock according to whether the same. The method of claim 30, Decoding the bitstream, And decoding the bit string for the DCT field in the bitstream using the adaptive decision bit when the target field is the DCT field. The method of claim 30, Decoding the bitstream, If the target field is a motion vector field, Decoding a bit string for the motion vector field in the bitstream into an absolute value of a motion vector using the decision bit; And Extracting a sine bit from the bitstream and restoring a motion vector by adding a sign corresponding to the extracted sine bit to an absolute value of the motion vector. The method of claim 30, Decoding the bitstream, If the target field is a motion vector field, Decoding a bit string for the motion vector field in the bitstream using the decision bit; Calculating an absolute value of a motion vector by adding a value less than a decimal point to the value of the decoded bit string; And Restoring a motion vector by adding a sign according to a sine bit to an absolute value of the motion vector, A value below the decimal point and the sign bit are extracted from a bitstream. The method of claim 30, Step (c) is, Decoding the bitstream, If the target field is a motion vector field, decoding a bit string corresponding to the motion vector field in the bitstream using the decision bit; Calculating an absolute value of a motion vector using at least one of the decoded bit string and a value below a decimal point according to an analysis result of the decoded bit string; And Calculating a motion vector by attaching a sign corresponding to a sign bit to an absolute value of the calculated motion vector, A value below the decimal point and the sign bit are extracted from a bitstream. In the recording medium in which a program of instructions that can be executed by a digital processing apparatus is tangibly embodied to perform a decoding method of a bitstream, and which records a program that can be read by the digital processing apparatus, Calculating an adaptive determination bit and an adaptive bit string for each symbol; Extracting a decision bit from the bitstream for each predetermined field; And Decoding the bitstream using at least one of the adaptive determination bit and the determination bit according to a type of a target field; The determination bit is a bit representing a length of a unit bit string for encoding the input data, And the adaptation determination bit is a bit indicating a length of a unit bit string having an optimal coding efficiency corresponding to the symbol among the lengths of the unit bit strings.

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