JP4855417B2 - Video encoding device, video decoding device - Google Patents

Description

  The present invention relates to a moving image encoding apparatus and a moving image decoding apparatus for realizing a high-efficiency encoding technique for moving image data.

  As a conventional technique for realizing high-efficiency encoding of moving image data, the H.264 / AVC moving image encoding technology described in Non-Patent Document 1 can be cited.

  A moving picture coding apparatus to which the H.264 / AVC moving picture coding technique is applied will be described with reference to the drawings.

  FIG. 13 is a block diagram of a conventional video encoding apparatus.

  In FIG. 13, reference numeral 1 is a frame memory for storing encoded images, reference numeral 2 is a prediction method control unit for determining a prediction method and a prediction parameter used for an image to be encoded, and reference numeral 3 is a frame memory 1. A prediction image generation unit that generates a prediction image from the encoded image stored in the image, reference numeral 4 is a difference image generation unit that generates a difference image between the image to be encoded and the prediction image, and reference numeral 5 is an orthogonality of the difference image. An orthogonal transform unit for transforming, 6 is a quantizing unit that quantizes the output data of the orthogonal transform unit 5 and outputs prediction residual data, and 7 is an inverse quantization of input data by an operation reverse to that of the quantizing unit 6 The inverse quantization unit, 8 is an inverse transform unit that performs inverse orthogonal transform of input data by the reverse operation of the orthogonal transform unit 5, and 9 is an image composition unit that synthesizes the output data of the inverse transform unit 8 and the predicted image. , 10 is A data scanning unit 11 that rearranges the two-dimensional data output from the sub-unit 6 into a one-dimensional data string by zigzag scanning. Reference numeral 11 denotes a variable length of the prediction method, the prediction parameter, and the prediction residual data for each element. It is a variable length encoding part to encode.

  The operation of the moving picture encoding apparatus having the above configuration will be described with reference to the operation flowchart of FIG. 14 in addition to FIG. Note that the moving image encoding apparatus performs the following processing for each macroblock composed of a 16 × 16 pixel rectangular area.

  STEP 1) The prediction method control unit 2 determines a prediction method and a prediction parameter used for the encoding target macroblock (S101).

  Here, as the prediction method, one of intra prediction and inter prediction (forward prediction, backward prediction, bidirectional prediction) is selected.

  In addition, as a prediction parameter, a prediction unit (macroblock division pattern), in the case of intra prediction, which of a plurality of intra prediction methods is applied, in the case of inter prediction, a motion vector is used for prediction. A combination of reference images is determined. Note that the prediction method and the prediction parameter determination method use a method in which a prediction image is generated by the prediction image generation unit 3 using a combination of all prediction methods and prediction parameters and has the highest correlation with the image to be encoded. However, since the processing amount is enormous, the prediction method and the prediction parameter that are candidates for selection are limited in advance, and the prediction method and the prediction parameter from which the predicted image with the highest correlation is obtained among the candidates are selected. It does not matter.

  STEP 2) The variable length coding unit 11 performs variable length coding on the prediction scheme and the prediction parameter determined by the prediction scheme control unit 2 for each element (S102).

  STEP 3) The predicted image generation unit 3 generates a predicted image of the macroblock based on the prediction method and the prediction parameter determined by the prediction method control unit 2 (S103).

  STEP 4) The difference image generation unit 4 generates a difference image between the macroblock image and the predicted image (S104).

  STEP 5) The orthogonal transformation unit 5 performs orthogonal transformation on the difference image of the macroblock for each 4 × 4 pixel block (S105).

  STEP 6) The quantization unit 6 quantizes the 4 × 4 block data output from the orthogonal transform unit 5 (S106).

  STEP 7) The inverse quantization unit 7 performs inverse quantization on the prediction residual data output from the quantization unit 6 (S107).

  STEP 8) The inverse transform unit 8 performs inverse orthogonal transform on the 4 × 4 block data output from the inverse quantization unit 7 (S108).

  STEP 9) The data scanning unit 10 performs zigzag scanning on the prediction residual data output from the quantization unit 6 and rearranges it into a one-dimensional data string (S109).

  STEP 10) The variable length coding unit 11 performs variable length coding on each element of the one-dimensional prediction residual data (S110).

  STEP 11) STEP 5 to 10 are repeated for all 4 × 4 pixel blocks constituting the macro block (S111).

  STEP12) The image composition unit 9 synthesizes the output data of the inverse transform unit 8 and the prediction image generated by the prediction image generation unit 3, encodes the combined image, and uses it as an encoded image for subsequent encoding. Therefore, it is stored in the frame memory 1 (S112).

STEP 13) STEPs 1 to 12 are repeated for all macroblocks constituting the image to be encoded (S113).
ITU-T Recommendation H.264: "Advanced Video Coding for generic audiovisual services" (2003)

  As described above, in the conventional moving image encoding apparatus, encoding information (prediction method, prediction parameter, prediction residual data, etc.) is encoded using a macroblock composed of a rectangular area of 16 × 16 pixels as a processing unit. Done. The macroblock size is constant both when encoding an image with a low spatial resolution and when encoding an image with a high spatial resolution. However, in general, the higher the spatial resolution, the higher the spatial correlation of the image to be encoded, and the encoded information tends to show a high correlation between adjacent macroblocks.

  Therefore, in the case of encoding a high-resolution image in which high correlation appears in a wider range than the macroblock size, the conventional moving image encoding device performs encoding utilizing a spatial correlation in a wide range. The problem of being unable to do so occurs.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to cover a wide range even when encoding a high-resolution image in which high correlation appears in a wider range than the macroblock size. It is an object of the present invention to provide a moving picture coding apparatus capable of performing coding utilizing the spatial correlation.

  In order to solve the above-described problem, the moving picture coding apparatus according to the present invention is a moving picture coding apparatus that divides and codes an image into a plurality of blocks, and encodes information necessary for coding each block. Temporary storage means for storing the encoding means, and encoding means for encoding a plurality of pieces of encoded information stored in the temporary storage means in units of M × N blocks (M and N are arbitrary integers). It is characterized by having.

  Specifically, the encoding means scans the M × N block encoding information stored in the temporary storage means by a predetermined scanning procedure and converts it into a one-dimensional data string; and A data string generating means for generating a plurality of one-dimensional data strings from the converted one-dimensional data string according to a predetermined rule; a data rearranging means for rearranging the generated one-dimensional data strings according to a predetermined sorting rule; It is preferable to include variable length encoding means for performing variable length encoding on the rearranged one-dimensional data string.

  Further, the data string converting means may perform conversion into a one-dimensional data string in a different scanning order for each type of the encoded information.

  Further, the data rearranging means may rearrange the one-dimensional data string using BWT (Burrows-Wheeler Transform).

  The data rearranging unit rearranges the one-dimensional data sequence for each M1 × N1 block when the spatial resolution to be encoded is less than a predetermined threshold, and the spatial resolution to be encoded is equal to or higher than a predetermined threshold. In this case, when the one-dimensional data string is rearranged for each M2 × N2 block, the relationship between the block sizes may satisfy M1 × N1 <M2 × N2.

  The encoding information includes data indicating a prediction method to be applied to a moving image to be encoded, a prediction parameter used together with the prediction method, and a prediction obtained by applying the prediction method to a moving image to be encoded Desirably at least one of the residual data.

  In order to solve the above-described problem, a moving image decoding apparatus according to the present invention is a moving image decoding apparatus that decodes moving image data encoded by the moving image encoding device. It is characterized by comprising decoding means for decoding the encoded information encoded with an arbitrary integer) as a unit.

  Further, the decoding means includes variable length decoding means for variable length decoding the encoded information, data string generation means for generating a plurality of one-dimensional data strings from the variable length decoded encoding information, A data rearranging means for rearranging the plurality of one-dimensional data strings according to a predetermined rearrangement rule, and a one-dimensional data string obtained by scanning the rearranged one-dimensional data string with encoding information of M × N blocks And a data string converting means for converting the data into the data string.

  The data string converting means may convert the data into a one-dimensional data string in a different reverse scanning order for each type of encoded information.

  The data rearranging means may rearrange the one-dimensional data string using inverse BWT (Burrows-Wheeler Transform).

  The data rearranging unit rearranges the one-dimensional data sequence for each M1 × N1 block when the spatial resolution to be encoded is less than a predetermined threshold, and the spatial resolution to be encoded is equal to or higher than a predetermined threshold. In this case, when the one-dimensional data string is rearranged for each M2 × N2 block, it is preferable that the relationship between the block sizes satisfies M1 × N1 <M2 × N2.

  The encoding information includes data indicating a prediction method to be applied to a moving image to be encoded, a prediction parameter used together with the prediction method, and a prediction obtained by applying the prediction method to a moving image to be encoded Desirably at least one of the residual data.

  As described above, the moving picture coding apparatus according to the present invention stores coding information necessary for coding each block in the moving picture coding apparatus that divides and codes an image into a plurality of blocks. Temporary storage means, and encoding means for encoding a plurality of pieces of encoded information stored in the temporary storage means with M × N blocks (M and N are arbitrary integers) as a unit. Therefore, it is possible to perform encoding in consideration of the high correlation between adjacent blocks due to the difference in spatial resolution. As a result, it is possible to perform encoding widely from low resolution images to high resolution images. Play.

  The moving picture decoding apparatus according to the present invention can decode and reproduce the highly efficient moving picture encoded data encoded by the moving picture encoding apparatus according to the present invention.

[Embodiment 1]
A video encoding apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a moving picture coding apparatus according to this embodiment.

  In FIG. 1, reference numeral 12 denotes a buffer memory for temporarily storing encoding information (prediction method, prediction parameter, prediction residual data) of a plurality of macroblocks, and reference numeral 13 denotes encoding information ( A data sort unit that rearranges prediction methods, prediction parameters, and prediction residual data) by a predetermined method, and a reference numeral 14 is a variable length encoding unit that performs variable length encoding on the output result of the data sort unit 13. The M × N block (M, N) is applied to a plurality of pieces of encoding information (prediction method, prediction parameter, prediction residual data) stored in the buffer memory 12 by the data sorting unit 13 and the variable length encoding unit 14. Constitutes an encoding unit (encoding means) 100 that performs encoding with an arbitrary integer) as a unit.

  In addition, about a block which has the same function as the moving image encoder (FIG. 13) of a prior art, the name and code | symbol are the same and description is abbreviate | omitted.

  An outline of the operation of the moving picture encoding apparatus having the above configuration will be described with reference to an operation flowchart of FIG. 2 in addition to FIG.

  STEP 1) The prediction method control unit 2 determines a prediction method and a prediction parameter used for the encoding target macroblock (S1).

  The prediction method and the prediction parameter determination method are the same as those of the conventional video encoding device, and the description thereof will be omitted. The determined prediction method and prediction parameter are recorded in the buffer memory 12.

  STEP 2) The predicted image generation unit 3 generates a predicted image of the macroblock based on the prediction method and the prediction parameter determined by the prediction method control unit 2 (S2).

  STEP 3) The difference image generation unit 4 generates a difference image between the macroblock image and the predicted image (S3).

  STEP 4) The orthogonal transformation unit 5 performs orthogonal transformation on the difference image of the macroblock for each 4 × 4 pixel block (S4).

  STEP 5) The quantization unit 6 performs quantization on the 4 × 4 block data output from the orthogonal transform unit 5. The output prediction residual data is recorded in the buffer memory 12 (S5).

  STEP 6) The inverse quantization unit 7 performs inverse quantization on the prediction residual data output from the quantization unit 6 (S6).

  STEP 7) The inverse transform unit 8 performs inverse orthogonal transform on the 4 × 4 block data output from the inverse quantization unit 7 (S7).

  STEP 8) STEPs 4 to 7 are repeated for all 4 × 4 pixel blocks constituting the macro block (S8).

  STEP 9) The image synthesis unit 9 synthesizes the output data of the inverse transformation unit 8 and the predicted image generated by the predicted image generation unit 3, and stores the generated image in the frame memory 1 for use in subsequent encoding. (S9).

  STEP 10) Steps 1 to 9 are repeated for all macroblocks constituting the image to be encoded (S10).

  STEP 11) The data sorting unit 13 includes each of a prediction method, a prediction parameter, and prediction residual data recorded in the buffer memory 12 in units of macro blocks each including M × N macro blocks (M and N are predetermined integers). Are rearranged in a predetermined procedure (S11). Details of the data sorting unit 13 will be described later.

  STEP 12) The variable length encoding unit 14 performs variable length encoding on each prediction method, prediction parameter, and prediction residual data output from the data sorting unit 13 in units of macroblock groups (S12). Details of the variable length coding unit 14 will also be described later.

  STEP 13) Steps 1 to 12 are repeated until encoding of all macroblock groups constituting the image to be encoded is completed (S13).

  With the above procedure, the moving image encoding apparatus according to the present embodiment encodes moving image data. In the above description, in STEPs 11 and 12, it has been described that the prediction scheme, the prediction parameter, and the prediction residual data are rearranged in units of macroblock groups, and each of them is variable length encoded. For example, prediction residual data) is input from the buffer memory 12 to the variable-length encoding unit 14 for each macroblock without passing through the data sorting unit 13, and is encoded in units of macroblocks as in the prior art. It does not matter.

  Next, details of the data sorting unit 13 will be described.

  The data sorting unit 13 converts input data of a predetermined macroblock group into a data string that can be efficiently variable-length encoded using BWT (Burrows-Wheeler Transform).

  BWT is a conversion for a one-dimensional data string. For example, when a data string in which the same pattern repeatedly appears, such as “0,1,0,1,0,1, ...”, the output data In the column, the conversion has the property that elements having the same value are more likely to be continuous than the input data sequence. Therefore, efficient variable length coding can be performed by performing code assignment (for example, run-length code) collectively on elements having a series of identical values.

  When handling data consisting of one element for one macroblock as in the prediction method, if the macroblock group is processed as, for example, 4 × 4 macroblocks (MB0 to MB15) as shown in FIG. If the input data is converted into a one-dimensional data string using any one of the scanning patterns shown in FIGS. 3B to 3G, the same pattern is likely to appear repeatedly due to the correlation between adjacent macroblocks. Therefore, by applying BWT, elements having the same value in the output data string can be easily continued, and efficient encoding becomes possible.

  Similarly, if the macroblock group is processed as an 8 × 8 macroblock, the output data string after BWT can be obtained by using any one of the scanning patterns shown in FIGS. 4 (a) to 4 (f). Thus, it can be expected that elements having the same value are likely to continue.

  Note that the strength of the correlation of the encoding information between adjacent macroblocks differs depending on the spatial resolution of the image to be encoded, so the size and scan pattern of the macroblock group that is the processing unit of the data sort unit 13 It is desirable to perform encoding simulation of a plurality of images in advance and use the combination with the best performance. For example, when encoding a low-resolution image, a macroblock group that processes 4 × 4 macroblocks is used as a high-resolution image. In the case of encoding an image of (2), if a macroblock group that processes 8 × 8 macroblocks is used, efficient encoding can be performed in consideration of the high correlation between adjacent macroblocks due to differences in spatial resolution. In addition, since the correlation level of the encoded information varies depending on the image to be encoded, a plurality of combinations may be prepared in advance, and a configuration that can adaptively select a combination to be used for encoding according to the image may be used. Absent. In addition, since the strength of the correlation is different for each element of the encoded information (prediction method, prediction parameter, prediction residual data), the size of the macroblock group and the scanning pattern are used for each element of the encoded information. It doesn't matter.

  FIG. 5 shows a specific operation example of the data sorting unit. FIG. 5A shows an example of input data to the data sorting unit 13, and here, an example in which data having element values 0 to 2 exists in each of 4 × 4 macroblocks. . For example, each element value represents a prediction method, and indicates 0: forward prediction, 1: backward prediction, 2: intra prediction.

  STEP1) When the scanning pattern shown in FIG. 3B is applied to FIG. 5A, the one-dimensional data string S0 shown in FIG. 5B is obtained.

  STEP2) Shift the elements of S0 to the left one element at a time and cycle the head element to the tail to generate a one-dimensional data string S1. Similar operations are repeated to generate S1 to S15 (FIG. 5C).

  STEP 3) Sort S0 to S15 in ascending order under the following conditions (FIG. 5 (d)).

For two one-dimensional data strings Sa: = Ea0, Ea1, Ea2,..., Ea15, Sb: = Eb0, Eb1,.
Condition 1: Sa <Sb if Ea0 <Eb0
Condition 2: Eai = Ebi (any i satisfying 0 ≦ i <i <j), and if Eaj <Ebj, Sa <Sb
STEP 4) The last element of the sorted S0 to S15 is used as an output data string in order, and the rank of S0 in the sorted result is output as additional information necessary for decoding (FIG. 5 (e)).

  In the above description, the case where the data sort unit 13 handles data consisting of one element in one macroblock has been described. However, data having a plurality of elements in one macroblock can be handled in the same manner.

  For example, a prediction method that is a prediction parameter in intra prediction is performed for each sub macroblock obtained by dividing one macro block into 4 × 4 sub macro blocks (B0 to B15) as in the example illustrated in FIG. Although there is data, the patterns shown in FIGS. 6B to 6G may be used in consideration of the correlation between adjacent sub-macroblocks as in the scanning pattern in units of macroblocks.

  The same applies to the case where there is a parameter for each sub-macroblock of variable size, such as designation of a motion vector or a reference image that is a prediction parameter for inter-frame prediction. For example, when variable-sized sub-macroblocks B0 to B4 as shown in FIG. 7A exist, the scanning pattern itself is determined in the same manner as in the example of the fixed-size sub-block (FIG. 6), and overlapping sub-blocks. When the macroblock is scanned, the second and subsequent scans may be ignored. For example, in the case of the scanning pattern of FIG. 7B, B0, B1, B2, B3, and B4 are output. In the case of FIG. 7C, B0, B4, B1, B2, and B3 are output. In the case of (d), B0, B1, B4, B3, and B2 are output.

  Similarly, in the case of prediction residual data, it is considered that there is a high correlation in the same frequency component between adjacent blocks, so that four adjacent blocks (B0, B1, B4, As shown in the order of numerical values in the figure, the operation sequence of the prediction residual data of 16 × 4 elements existing in B5) is scanned from the low frequency component to the high frequency component, and the same scanning is applied to the remaining blocks. good.

  Next, details of the variable length coding unit 14 will be described. As described above, the variable length encoding unit 14 of the present embodiment uses the property that the data strings output from the data sorting unit 13 have the same value easily and can be efficiently changed by run length encoding. Perform long coding. In the run-length encoding, variable length encoding such as Goram code, Huffman code, or arithmetic code shown in Table 1 below may be used for encoding each element.

  As a specific operation example of the variable length encoding unit 14, a case will be described in which the output result of FIG. 5 used in the description of the data sorting unit 13 is variable length encoded. For explanation, the Goram code of Table 1 is used for encoding each element. In addition, when encoding using the Goram code of Table 1, it is efficient by predetermining that the appearance probability of each element value is the highest when the element value is 0, and the appearance probability decreases as the element value increases. Encoding becomes possible.

When the data string "2, 2, 2, 2, 0 , 0 , 0 , 0 , 0 , 0 , 0, 2, 1 , 1 , 1 , 0 " is expressed by repetition of element values and run lengths, "2, 4, 0, 7, 2, 1, 1, 3, 0, 1 ". On the other hand, the code words in Table 1 are assigned. However, since run length 0 does not exist, when codewords are assigned using run length −1 as an element value,
"011, 00100, 1, 00111, 011, 1, 010, 011, 1, 1 ". Furthermore, 0 which is the rank of the sorting result of S0 is applied to Table 1 and encoded,
A total of 27 bits “011, 00100 , 1, 00111, 011 , 1, 010, 011 , 1, 1, 1” is the output of the variable length coding unit 14.

  For reference, as in the prior art, the input data string S0 = “0, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 0, 0, 2, 2” in FIG. When each element of the above is individually variable-length-coded using Table 1, "1, 1, 010, 011, 1, 1, 010, 011, 1, 1, 010, 011, 1, 1, 011, 011 Therefore, it can be seen that the variable length coding by the moving picture coding apparatus of this embodiment has better 5-bit coding efficiency.

  Further, by predicting the element values that appear, further improvement in encoding efficiency can be expected.

  For example, the encoding procedure using prediction is as follows.

  STEP1) Initialize the candidate column of predicted values in descending order of element values. The candidate string of predicted values indicates that the closer to the head, the higher the probability of appearance, and the closer to the tail, the lower the probability of appearance.

  STEP2) Search for the number in the candidate column of the predicted value that the first element value of the input data sequence appears.

  STEP3) Output the index and run length-1 of the predicted value obtained by the search, and variable-length encode each.

  STEP 4) The prediction candidates from the beginning of the prediction value candidate sequence to the prediction value index obtained in STEP 2 are moved to the end of the prediction candidate sequence.

  STEP 5) Repeat steps 2 to 4 until all data strings in the input data string are encoded.

FIG. 9 shows that the above-described data string “2, 2, 2, 2 , 0 , 0 , 0 , 0 , 0 , 0 , 0, 2, 1 , 1 , 1 , 0 ” is encoded according to the above-described procedure. In this example, “1, 00100 , 010, 00111 , 1, 1 , 1, 011 , 1, 1 ” are obtained as output results. If the result of encoding 0, which is the order of the sorting result of S0, is added to this, it becomes 23 bits in total, “1, 00100 , 010, 00111 , 1, 1, 1, 011 , 1, 1, 1”. It can be seen that more efficient encoding is performed than simple run-length encoding.

   As described above, in the video encoding device of the present embodiment, variable length encoding is performed using the correlation between macroblocks or sub-macroblocks. Efficiency can be increased.

[Embodiment 2]
Next, as another embodiment of the present invention, a moving picture decoding apparatus for decoding encoded data encoded by the moving picture encoding apparatus of the first embodiment will be described.

  FIG. 10 is a block diagram showing the video decoding device of the present embodiment.

In FIG. 10, code 15 is a variable-length code decoding unit that performs variable-length decoding of encoded data, and code 16 rearranges a one-dimensional data sequence obtained by variable-length decoding by a predetermined operation, and data for each macroblock. It is a data reverse sort part which restores to.
In addition, about a block which has the same function as the moving image encoder of Embodiment 1, the name and code | symbol are the same and description is abbreviate | omitted.

  Next, the operation of the moving picture decoding apparatus of the present embodiment will be described below with reference to the operation flow of FIG. 11 in addition to FIG.

  STEP 1) The variable length code decoding unit 15 performs variable length decoding on the encoded data, and restores the prediction method, prediction parameters, and prediction residual data of the output state of the data sorting unit 13 in the moving image encoding device shown in FIG. . Details of the variable-length code decoding unit 15 will be described later (S1).

  STEP 2) The data reverse sorting unit 16 rearranges the one-dimensional data sequence (encoded information) input from the variable length decoding unit 15 into a two-dimensional data sequence by a predetermined procedure and records it in the buffer memory 12 (S2). Note that the data storage format recorded in the buffer memory is the same as the data storage format in the buffer memory in the video encoding apparatus of Embodiment 1, and details of the operation of the data reverse sort unit 16 will be described later.

  STEP 3) STEPs 1 and 2 are repeated until the data of all the macroblock groups constituting the screen are restored (S3).

  STEP 4) The inverse quantization unit 7 receives the prediction residual data from the buffer memory 12 and performs inverse quantization (S4).

  STEP 5) The inverse transform unit 8 performs inverse orthogonal transform on the 4 × 4 block data output from the inverse quantization unit 7 (S5).

STEP 6) STEPs 4 to 5 are repeated for all 4 × 4 pixel blocks constituting the macro block (S6).
STEP 7) The predicted image generation unit 3 reads the prediction method and the prediction parameters from the buffer memory 12, and generates a predicted image based on the decoded images stored in the frame memory 1 (S7).
STEP 8) The image synthesis unit 9 synthesizes the output data of the inverse transformation unit 8 and the predicted image generated by the predicted image generation unit 3 and stores the generated image in the frame memory 1 for use in subsequent decoding. And output to the outside (S8).
STEP 9) Repeat STEPs 4 to 8 for all macroblocks constituting the image (S9).

  Next, the variable length code decoding unit 15 will be described in detail.

  The operation of the variable length code decoding unit 15 performs the reverse operation of the variable length coding unit 14 in the first embodiment.

When decoding the encoded data that has been encoded by the simple run length described above, the input encoded data string "011, 00100 , 1, 00111 , 011 , 1, 010 , 011 , 1, 1, 1" Applying to Table 1 above, "2, 3, 0, 6, 2, 0, 1, 3, 0" is obtained, and the restoration of the run and the order of S0 are separated, and the data string "2, 2, 2 , 2, 0 , 0 , 0 , 0 , 0 , 0 , 0 , 2, 1 , 1 , 1 , 0 ", S0 rank: 0 is completely decoded.

  In addition, when encoding using a predicted value is performed, decoding is performed according to the following procedure.

  STEP1) Initialize the candidate sequence of predicted values in the descending order of the element values, similar to encoding.

  STEP2) Decode the predicted index and run length based on the code assignments in Table 1.

  STEP 3) The value pointed to by the index of the prediction value obtained in STEP 2 in the prediction candidate string is decoded as an element value.

  STEP 4) The prediction candidate sequence is updated based on the prediction value index as in the case of encoding.

  STEP5) Repeat steps 1 to 4 until all elements are decoded.

  STEP 6) Decode the order of S0 based on the code assignment in Table 1 to complete the decoding.

Next, the operation of the data reverse sort unit 16 will be described with reference to FIG. 12 in the case where the example (FIG. 5) used in the description of the operation of the data sort unit is restored. In the following description, it is assumed that the data reverse sort unit 16 receives the data string shown in FIG. 12A and the order of S0. Note that this input data is the same as the output result of FIG. 5E described above.
STEP 1) The last element value of S0 to S15 in FIG. 5D is restored by assigning the input data string in the order of ranks 0 to 15 (FIG. 12B).

 Further, the head elements of S0 to S15 in FIG. 5D are obtained by rearranging the input data string in ascending order. It should be noted that the order of S1 to S15 other than S0 is unknown at this point.

  STEP2) The last elements of S0 to S15 in FIG. 12C are designated as e0, e1,..., E15 from the higher order elements (in order from the top of the figure). The first elements of S0 to S15 having the same element value are searched in order from e0 to e15, and the same symbol is assigned. If there are a plurality of the same element values, the same symbol is assigned to the upper element.

  STEP 3) Shift all elements other than the last of S0 to S15 back to one, and move the last element to the beginning (FIG. 12 (d)). By this operation, it becomes clear which element follows each element of e0, e1,..., E15.

  STEP4) The third to fourteenth elements of S0 are determined based on the information obtained in FIG. 12 (d) (FIG. 12 (e)).

  STEP 5) Replace the symbols assigned to each element of S0 with the corresponding element values (FIG. 12 (f)).

  STEP 6) Using the scanning pattern used in the moving picture coding apparatus of the first embodiment, the one-dimensional data is converted into two-dimensional data on the contrary, each element value of the coding information in the MxN macroblock is restored, and the buffer The data is output to the memory 12 (FIG. 12 (g)).

  The encoded data generated by the video encoding apparatus of Embodiment 1 can be decoded by the operation described above.

  In the above description, the macro block size and the sub macro block size are the same as those in the conventional technology, but a configuration using different sizes may be used. Further, the macroblock group size may be different for each element of the encoding information (prediction method, prediction parameter, prediction residual data).

  The moving image encoding method of the present invention is a moving image encoding method for dividing and encoding an image into a plurality of blocks, and temporarily storing encoding information necessary for encoding each block. And a step of encoding the plurality of pieces of encoded information stored in the above step using M × N blocks (M and N are arbitrary integers) as a unit.

  The encoding step includes a data string conversion step of scanning the temporarily stored encoding information of the M × N block by a predetermined scanning procedure to convert it into a one-dimensional data string; A data sequence raw step for generating a plurality of one-dimensional data sequences from a dimensional data sequence according to a predetermined rule, a data rearrangement step for rearranging the generated one-dimensional data sequences according to a predetermined rearrangement rule, And a variable length encoding step for performing variable length encoding on the one-dimensional data string.

  The moving image decoding method of the present invention is a moving image decoding method for decoding moving image data encoded by the moving image encoding method, wherein M × N blocks (M and N are arbitrary integers) are encoded as a unit. And a step of decoding the encoded information.

  The moving image decoding method of the present invention is a moving image decoding method for decoding moving image data encoded by the moving image encoding method, wherein M × N blocks (M and N are arbitrary integers) are encoded as a unit. A decoding step for decoding the encoded information, wherein the decoding step includes a variable-length decoding step for variable-length decoding the encoded information, and a plurality of one-dimensional data from the variable-length decoded encoding information. A data sequence generation step for generating a data sequence, a data rearrangement step for rearranging the generated one-dimensional data sequences according to a predetermined rearrangement rule, and the rearranged one-dimensional data sequence as an M × N block code And a data string converting step for converting the information into a one-dimensional data string obtained by scanning.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  Finally, each block of the moving picture coding apparatus, in particular, the data sorting unit 13 and the variable length coding unit 14 may be configured by hardware logic, or realized by software using a CPU as follows. Also good.

  That is, the moving image encoding apparatus includes a CPU (central processing unit) that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, and a RAM (random access memory) that expands the program. ), A storage device (recording medium) such as a memory for storing the program and various data. An object of the present invention is a recording medium in which a program code (execution format program, intermediate code program, source program) of a control program of a moving image encoding apparatus, which is software that realizes the functions described above, is recorded in a computer-readable manner. Can also be achieved by reading the program code recorded on the recording medium and executing it by the computer (or CPU or MPU).

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  Further, the moving image encoding apparatus may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Further, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The present invention can also be applied to a device that requires high-efficiency encoding of high-definition moving image data, such as a recording / playback device such as an HDTV.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of the present invention, and is a block diagram illustrating a main configuration of a moving image encoding device. It is a flowchart which shows the flow of the encoding process by the moving image encoder shown in FIG. (A) is a figure which shows an example of a 4x4 macroblock, (b)-(g) is a figure which shows the scanning pattern of the macroblock shown by (a). (A)-(f) is a figure which shows the scanning pattern of an 8x8 macroblock. (A)-(d) is a flowchart which shows the flow of the data sort process by the data sort part with which the moving image encoder shown in FIG. 1 was equipped. (A) is a figure which shows an example of a 4x4 fixed size macroblock, (b)-(g) is a figure which shows the scanning pattern of the macroblock shown by (a). (A) is a figure which shows an example of a variable size macroblock, (b)-(g) is a figure which shows the scanning pattern of the macroblock shown by (a). It is a figure which shows the example of the scanning pattern of prediction residual data. It is a figure which shows an example of the variable length encoding method by the variable length encoding part with which the moving image encoding apparatus shown in FIG. 1 was equipped. FIG. 29, showing another embodiment of the present invention, is a block diagram illustrating a main configuration of a video decoding device. It is a flowchart which shows the flow of the decoding process of the moving image decoding apparatus shown in FIG. (A)-(g) is a figure which shows the flow of the data reverse sort process by the data reverse sort part with which the moving image decoding apparatus shown in FIG. 10 was equipped. It is a block diagram which shows the principal part structure of the conventional moving image encoder. It is a flowchart which shows the flow of the encoding process of the moving image encoder shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Frame memory 2 Prediction system control part 3 Predictive image generation part 4 Difference image generation part 5 Orthogonal transformation part 6 Quantization part 7 Inverse quantization part 8 Inverse transformation part 9 Image composition part 12 Buffer memory (temporary storage means)
13 Data sorting part (data sorting means)
14 Variable length encoding unit 15 Variable length code decoding unit 16 Data reverse sort unit (data rearrangement means)
100 Encoding unit (encoding means)

Claims (8)

In a moving image encoding apparatus that divides and encodes an image into a plurality of blocks,
Temporary storage means for storing encoding information necessary for encoding each block;
Encoding means for encoding a plurality of pieces of encoded information stored in the temporary storage means with M × N blocks (M and N are arbitrary integers) as a unit;
The encoding means includes
Data sequence conversion means for scanning the M × N block encoding information with a predetermined scanning procedure and converting it into a one-dimensional data sequence for a plurality of pieces of encoding information stored in the temporary storage means;
Data string rearranging means for rearranging the converted one-dimensional data string according to a predetermined sorting rule;
Variable length encoding means for performing variable length encoding on the rearranged one-dimensional data string ,
The data string conversion means includes:
When the block size relationship satisfies M1 × N1 <M2 × N2,
When the spatial resolution to be encoded is less than a predetermined threshold, the encoding information is converted into a one-dimensional data string for each M1 × N1 block ,
An apparatus for encoding a moving picture, wherein the encoding information is converted into a one-dimensional data sequence for each M2 × N2 block when the spatial resolution to be encoded is equal to or greater than a predetermined threshold. The data string conversion means includes:
The moving image encoding apparatus according to claim 1 , wherein conversion into a one-dimensional data string is performed in a different scanning order for each type of the encoded information. The data string rearranging means includes:
Using BWT (Burrows-Wheeler Transform), the moving picture coding apparatus according to claim 1, characterized in that rearranging of one-dimensional data sequence. The encoding information includes data indicating a prediction method to be applied to a moving image to be encoded, a prediction parameter used together with the prediction method, and a prediction obtained by applying the prediction method to a moving image to be encoded The moving picture encoding apparatus according to any one of claims 1 to 3 , wherein there is at least one residual data. In a video decoding device that decodes video data divided into a plurality of blocks ,
A decoding means for decoding encoded information encoded with M × N blocks (M and N are arbitrary integers) as a unit;
The decoding means includes
Variable-length decoding means for variable-length decoding encoded encoding information;
Data sequence rearranging means for rearranging a plurality of one-dimensional data sequences from the variable length decoded encoded information according to a predetermined rearrangement rule;
Data string conversion means for converting the rearranged one-dimensional data string into a one-dimensional data string obtained by scanning the encoded information of M × N blocks ,
The data string conversion means includes:
When the block size relationship satisfies M1 × N1 <M2 × N2,
When the spatial resolution to be encoded is less than a predetermined threshold, the encoding information is converted into a one-dimensional data string for each M1 × N1 block ,
A moving picture decoding apparatus, wherein the encoding information is converted into a one-dimensional data sequence for each M2 × N2 block when the spatial resolution to be encoded is equal to or greater than a predetermined threshold. 6. The moving picture decoding apparatus according to claim 5 , wherein the data string converting means converts the data into a one-dimensional data string in a different reverse scanning order for each type of the encoded information. 6. The moving picture decoding apparatus according to claim 5 , wherein the data string rearranging means rearranges the one-dimensional data string using inverse BWT (Burrows-Wheeler Transform). The encoding information includes data indicating a prediction method to be applied to a moving image to be encoded, a prediction parameter used together with the prediction method, and the prediction method to a moving image to be encoded. The moving picture decoding apparatus according to claim 5 , wherein at least one prediction residual data obtained by application is at least one.

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