JP6717562B2 - Image coding method, image decoding method, image coding device, and image decoding device - Google Patents

Description

The present invention relates to an image coding method and an image decoding method.

As a technique related to an image encoding method for encoding an image (including a moving image) or an image decoding method for decoding an image, there is a technique described in Non-Patent Document 1.

Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC JTC1/SC29/WG11 12th Meeting: Geneva, J., 14-23. 2013 JCTVC-L1003_v34. doc, High Efficiency Video Coding (HEVC) text specification draft 10 (for FDIS & Last Call) http: //phenix. it-suparis. eu/jct/doc_end_user/documents/12_Geneva/wg11/JCTVC-L1003-v34. zip

However, in the image encoding method or the image decoding method according to the related art, inefficient processing may be used.

Therefore, the present invention provides an image coding method for efficiently coding an image or an image decoding method for efficiently decoding an image.

An image coding apparatus according to an aspect of the present invention is an image coding method for performing arithmetic coding on an image signal, wherein a context used for the arithmetic coding, a Range indicating a section, and a minimum position of the section. A coding step for coding information for deriving at least any one of the Low positions indicating the following, and an initialization step for initializing the arithmetic coding based on the information at the start of the arithmetic coding of the image signal. including.

An image decoding method according to an aspect of the present invention is an image decoding method for performing arithmetic decoding on a bitstream generated by encoding an image, and is a Range indicating a context and a section used for the arithmetic decoding. And a decoding step of decoding information for deriving at least one of a Low position indicating the minimum position of the section, and an initialization for initializing the arithmetic decoding based on the information at the start of the arithmetic decoding of the bitstream. And steps.

Note that these general or specific aspects may be realized by a recording medium such as a system, a method, an integrated circuit, a computer program or a computer-readable CD-ROM, and the system, the method, the integrated circuit, the computer program. It may be realized by any combination of the recording medium and the recording medium.

The image encoding method and the image decoding method of the present invention can efficiently encode or decode an image.

3 is a block diagram of an image coding apparatus according to Embodiment 1. FIG. 7 is a flowchart of an image encoding process according to the first embodiment. 4 is a block diagram of a variable length coding unit according to the first embodiment. FIG. 6 is a flowchart of a variable length coding process according to the first embodiment. 5 is a flowchart of a context initial value setting process according to the first embodiment. FIG. 6 is a diagram showing an example of a context index according to the first embodiment. 5 is a flowchart of arithmetic encoder initial value setting processing according to the first embodiment. 5 is a flowchart of context storage processing according to the first embodiment. 5 is a flowchart of arithmetic encoder data storage processing according to the first embodiment. FIG. 6 is a diagram showing syntax related to initial values of context, Range and Low positions according to the first embodiment. 7 is a block diagram of an image decoding device according to Embodiment 2. FIG. 9 is a flowchart of image decoding processing according to the second embodiment. FIG. 6 is a block diagram of a variable length decoding unit according to the second embodiment. 9 is a flowchart of a variable length decoding process according to the second embodiment. 9 is a flowchart of a context initial value setting process according to the second embodiment. 7 is a flowchart of arithmetic decoder initial value setting processing according to the second embodiment. 1 is an overall configuration diagram of a content supply system that realizes a content distribution service. 1 is an overall configuration diagram of a digital broadcasting system. It is a block diagram which shows the structural example of a television. FIG. 3 is a block diagram showing a configuration example of an information reproducing/recording unit that reads and writes information from and on a recording medium that is an optical disc. It is a figure which shows the structural example of the recording medium which is an optical disk. It is a figure which shows an example of a mobile telephone. It is a block diagram which shows the structural example of a mobile telephone. It is a figure which shows the structure of multiplexed data. It is a figure which shows typically how each stream was multiplexed in the multiplexed data. It is a figure which showed in more detail how a video stream is stored in a PES packet sequence. It is a figure which shows the structure of the TS packet and source packet in multiplexed data. It is a figure which shows the data structure of PMT. It is a figure which shows the internal structure of multiplexed data information. It is a figure which shows the internal structure of stream attribute information. It is a figure which shows the step which identifies video data. It is a block diagram which shows the structural example of the integrated circuit which implement|achieves the moving image encoding method and moving image decoding method of each embodiment. It is a figure which shows the structure which switches a drive frequency. It is a figure which shows the step which identifies video data and switches a drive frequency. It is a figure which shows an example of the look-up table which matched the standard and drive frequency of video data. It is a figure which shows an example of the structure which shares the module of a signal processing part. It is a figure which shows another example of the structure which shares the module of a signal processing part.

(Findings that form the basis of the present invention)
The present inventor has found that the following problems occur in the image coding apparatus that codes an image or the image decoding apparatus that decodes an image described in the “Background Art” section.

2. Description of the Related Art In recent years, technological advances in digital video equipment have been remarkable, and video signals (a plurality of pictures arranged in chronological order) input from a video camera or a TV tuner are compression-coded, and the obtained data is a recording medium such as a DVD or a hard disk. The chances of being recorded in are increasing. The image encoding standard is H.264. Although there is H.264/AVC (MPEG-4 AVC), the HEVC (High Efficiency Video Coding) standard (Non-Patent Document 1) has been standardized as a next-generation standard.

An image encoding method according to the HEVC standard (Non-Patent Document 1) includes a step of predicting an encoded image, a step of obtaining a difference between a predicted image and an image to be encoded, and a step of converting the difference image into a frequency coefficient. Arithmetically encoding the frequency coefficient and the prediction information. In arithmetic coding, an image coding apparatus first converts (binarizes) a signal to be coded from a multi-valued signal into a binary signal (a signal of 0 and 1) and arithmetically codes a binary signal (bin). By doing so, a code string is generated. In arithmetic coding, the image coding apparatus selects a context for each signal to be coded, sets a section based on the symbol occurrence probability according to the context, and sends the code string. Further, the image coding apparatus updates the symbol occurrence probability of the context according to the value of the coded target signal, and at the same time, indicates the width of the section in the arithmetic encoder and the Low indicating the position below the section. Position and update.

Here, in the arithmetic coding, parallel processing is difficult because the context, the Range, and the Low position are sequentially updated as described above. In recent years, the size of an image has increased to 4K or 8K, and since there are many multi-core processors, there are many demands for distributed processing to realize high-speed processing. In the HEVC standard, there are tools for slicing, tile partitioning, and WPP (wavefront parallel processing) as means for solving this. Slice division and tile division are tools that enable parallel processing by eliminating the context, slice and tile position dependency between slices or tiles.

WPP is a tool for copying the coded context of the upper right code block and using it when the code block is at the left end of the screen. In WPP, the code block at the left end of the screen can start encoding after the code block at the upper right is encoded. Thereby, the learning efficiency of context and parallel processing can be compatible. There is also a tool called non-independent slice segment, which is a tool for slice division while leaving context dependency.

However, since the slice division and the tile division eliminate the context dependency, the previously learned symbol occurrence probability cannot be used. As a result, there is a problem that the coding efficiency is reduced. Further, in WPP, the Range and Low positions must be updated independently for each code block string, and therefore the bit discharge process inside the arithmetic encoder is required at the end of the code block string (the right end block of the screen). As a result, there is a problem that the coding efficiency is reduced.

An image coding method according to an aspect of the present invention is an image coding method that performs arithmetic coding on an image signal, and includes a context used for the arithmetic coding, a range indicating a section, and a minimum position of the section. A coding step for coding information for deriving at least any one of the Low positions indicating the following, and an initialization step for initializing the arithmetic coding based on the information at the start of the arithmetic coding of the image signal. including.

For example, the information includes an index that specifies one of a plurality of sets of initial values of the context, and the initialization step uses the set of initial values specified by the index to perform the initialization. Good.

For example, the information includes a flag for switching between a mode for setting an initial value by a predetermined fixed value and a mode for setting an initial value based on the information in the code string, and in the initialization step, The initialization may be performed using a mode designated by the flag.

An image decoding method according to an aspect of the present invention is an image decoding method for performing arithmetic decoding on a bitstream generated by encoding an image, and is a Range indicating a context and a section used for the arithmetic decoding. And a decoding step of decoding information for deriving at least one of a Low position indicating the minimum position of the section, and an initialization for initializing the arithmetic decoding based on the information at the start of the arithmetic decoding of the bitstream. And steps.

For example, the information includes an index that specifies one of a plurality of sets of initial values of the context, and the initialization step uses the set of initial values specified by the index to perform the initialization. Good.

For example, the information includes a flag for switching between a mode for setting an initial value by a predetermined fixed value and a mode for setting an initial value based on the information in the code string, and in the initialization step, The initialization may be performed using a mode designated by the flag.

An image coding apparatus according to an aspect of the present invention is an image coding apparatus that performs arithmetic coding on an image signal, and includes a context used for the arithmetic coding, a Range indicating a section, and a section indicating the section. An encoding unit that encodes information for deriving at least one of a Low position indicating a minimum position, and an initialization unit that initializes the arithmetic coding based on the information when the arithmetic coding of the image signal is started. And a section.

An image decoding device according to an aspect of the present invention is an image decoding device that performs arithmetic decoding on a bitstream generated by encoding an image, and is a Range indicating a context and a section used for the arithmetic decoding. And a decoding unit for decoding information for deriving at least one of a Low position indicating the minimum position of the section, and an initialization for initializing the arithmetic decoding based on the information when the arithmetic decoding of the bitstream is started. And a section.

Note that these general or specific aspects may be realized by a recording medium such as a system, a method, an integrated circuit, a computer program or a computer-readable CD-ROM, and the system, the method, the integrated circuit, the computer program. It may be realized by any combination of the recording medium and the recording medium.

Hereinafter, embodiments will be specifically described with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of constituent elements, steps, order of steps, and the like shown in the following embodiments are examples, and are not intended to limit the present invention.

(Embodiment 1)
<Overall structure>
FIG. 1 is a block diagram showing the configuration of image coding apparatus 100 according to the present embodiment. The image coding apparatus 100 shown in FIG. 1 includes a code block division unit 101, a subtraction unit 102, a conversion unit 103, a variable length coding unit 104, an inverse conversion unit 105, an addition unit 106, and a frame memory 107. And a prediction unit 108.

<Operation (overall)>
Next, the flow of the entire encoding process will be described with reference to FIG.

First, the code block division unit 101 divides the input image into code blocks, and sequentially outputs the code blocks to the subtraction unit 102 and the prediction unit 108 (S111).

Next, the prediction unit 108 generates a prediction block (S112). The subtraction unit 102 generates a difference block by subtracting the prediction block from the code block (S113). The conversion unit 103 frequency-converts the difference block to generate quantized coefficients (S114). The inverse transform unit 105 generates a decoded difference block by performing inverse frequency transform on the quantized coefficient (S115).

The addition unit 106 generates a decoded block by adding the prediction block and the decoded difference block (S116). This decoded block is stored in the frame memory 107 and used for the prediction process by the prediction unit 108. Also, the variable length coding unit 104 variable length codes the quantized coefficient to generate a code string (S117). In addition, the image coding apparatus 100 repeats S112 to S117 until the coding of all code blocks in the coding target image is completed (S118).

Hereinafter, the characteristic variable length coding unit 104 will be described in detail.

<Structure of variable length coding unit 104>
FIG. 3 is a block diagram showing the configuration of the variable length coding unit 104. The variable length coding unit 104 includes a binarization unit 111, an arithmetic coding unit 112, a context storage unit 113, a context initial value setting unit 114, an arithmetic encoder data storage unit 115, and an arithmetic encoder. An initial value setting unit 116 and a Golomb coding unit 117 are provided.

Arithmetic encoding is encoding using the occurrence probability (context value) of each bit in a binary signal to be encoded, and realizes high compression of a signal by dividing and updating an interval with a probability value. .. For example, when the probability that a certain bit of a binary signal is "0" is 0.7 and the probability that it is "1" is 0.3, if "0" is encoded, the bit is encoded. A 70% portion from the bottom of the used section is set to a new section. When "1" is encoded, the upper 30% of the section is set as a new section. In arithmetic coding, the intervals are sequentially shortened by repeating this interval update, and the output signal of the arithmetic coding unit 112 is generated using the binary representation of the real value included in the final interval.

<Variable length coding processing>
Next, the variable length coding process (S117) will be described with reference to FIG.

First, the context initial value setting unit 114 sets the initial value of the context corresponding to the probability of use in arithmetic coding (S131). The arithmetic encoder initial value setting unit 116 sets an initial value of Range indicating a section used during arithmetic encoding and an initial value of a Low position indicating a minimum position of the section (S132).

Next, the binarizing unit 111 binarizes the syntax element to be encoded to generate a binary signal (S133). The arithmetic coding unit 112 arithmetically codes the binary signal (S134). In the arithmetic coding, the arithmetic coding unit 112 updates the Range, the Low position and the context, and normalizes (transmits bits).

Next, the context storage unit 113 and the arithmetic encoder data storage unit 115 store the updated context, Range and Low position (S135 and S136).

The variable-length coding unit 104 repeats S131 to S136 until coding of all syntax elements in the code block is completed (S137).

The characteristic context initial value setting process (S131), arithmetic coder initial value setting process (S132), context storing process (S135), and arithmetic coder data storing process (S136) will be described in detail below.

<Context initial value setting process>
The context initial value setting process (S131) will be described with reference to FIG.

First, if the syntax element to be processed is the first syntax element of the independent slice segment or tile (Yes in S141), the context initial value setting unit 114 sets a context index (S142). This context index is encoded by the Golomb encoding unit 117 (S143). The context initial value setting unit 114 sets a value corresponding to the context index in the arithmetic coding unit 112 as a context initial value (S144).

Here, the independent slice segment is a slice segment that is not the above-described non-independent slice segment and has no context dependency relationship with the previously encoded slice segment. The context index is information indicating which of the set of initial values of the provided context groups is used.

FIG. 6 is a diagram showing an example of the context index. In this example, when the context index is 0, initial values “153”, “200”, and “185” are used for contexts having context numbers “0”, “1”, and “2”. The value of the context indicates information including MPS (symbol (0 or 1) with high occurrence probability) (HEVC standard valMps) and a number for deriving the occurrence probability (HEVC standard pStateIdx).

The context initial value setting unit 114 determines the context index using the characteristics of the input image and the like. Also, the context initial value setting unit 114 may provisionally perform the once encoding, and determine the context index based on the degree of efficient context to some extent.

On the other hand, if the syntax element to be processed is the first syntax element of the screen leftmost code block at the time of WPP (Yes in S145), or the first syntax element of the non-independent slice segment (Yes in S146). ), the storage context stored in the context storage unit 113 is set in the arithmetic coding unit 112 as a context initial value (S147). The context storage process will be described later.

<Arithmetic encoder initial value setting process>
The arithmetic coder initial value setting process (S132) will be described with reference to FIG.

Arithmetic if the syntax element to be processed is the first syntax element of the slice segment or tile (Yes in S151) or the first syntax element of the leftmost code block of the screen at WPP (Yes in S152) The encoder initial value setting unit 116 sets the arithmetic engine initialization type flag (S153) and sends the bits of the arithmetic engine initialization type flag to the code string (S154). Here, the slice segment includes both independent and non-independent slice segments. The arithmetic engine initialization type flag is a flag for switching between the HEVC method and the method of copying and using the stored Range and stored Low positions. For example, the arithmetic coder initial value setting unit 116 determines the arithmetic engine initialization type flag using the number of slices or tile divisions and the characteristics of the input image. The arithmetic engine initialization type flag may be arbitrarily set by the user who performs the encoding.

Next, when the arithmetic engine initialization type flag is “0” (Yes in S155), the arithmetic encoder initial value setting unit 116 sets “510” as the Range initial value and “0” as the Low position initial value. It is set in the arithmetic coding unit 112 (S156 and S157). That is, the arithmetic encoder initial value setting unit 116 sets the fixed value to the initial value of the Range and Low positions.

On the other hand, when the arithmetic engine initialization type flag is “1” (No in S155), the Golomb coding unit 117 sets the stored Range stored in the arithmetic coder data storage unit 115 as the Range initial value and sets the arithmetic code. Golomb coding is performed using the stored Low position stored in the digitizer data storage unit 115 as the Low position initial value (S158 and S159). The arithmetic encoder data storage processing will be described later.

Next, the arithmetic encoder initial value setting unit 116 sets the Range initial value and the Low position initial value in the arithmetic encoder 112 (S160 and S161).

<Context storage processing>
The context storing process (S135) will be described with reference to FIG.

When the syntax element to be processed is the last syntax element of the second code block from the left end in WPP (Yes in S161), or the last syntax element of the slice segment (Yes in S162) The context storage unit 113 copies (saves) the updated context to the storage context (S163). This is because this storage context is used at the head block (left end block) of the next code block sequence at the time of WPP or the head of the next non-independent slice segment. This storage context is used as a context initial value in S147 of FIG.

<Arithmetic encoder data storage processing>
The arithmetic encoder data storage processing (S136) will be described with reference to FIG.

When the syntax element to be processed is the last syntax element of the slice segment or tile (Yes in S171), or the last syntax element of the rightmost code block in WPP (Yes in S172). If there is and the arithmetic engine initialization type flag is 0 (Yes in S173), the arithmetic encoder data storage unit 115 performs a transmission process for ejecting the bits remaining in the arithmetic encoder (S174). When the arithmetic engine initialization type flag is not 0 (1) (No in S173), the arithmetic encoder data storage unit 115 copies the updated Range and Low positions to the stored Range and stored Low positions. (Evacuation) (S175 and S176). This is because the storage Range and storage Low positions are used at the head of the next slice segment or the head block (left end block) of the next code block sequence at the time of WPP. The stored Range and the stored Low position are used as the Range initial value and the Low position initial value in S158, S159, S160, and S161 of FIG.

<Effect>
As described above, according to the present embodiment, by encoding the Range and Low positions, it is possible to suppress a decrease in encoding efficiency when slice division, tile division, or WPP is used. More specifically, encoding the Range and Low positions allows the internal state of the arithmetic encoder to continue to be used for the next slice, tile or code block sequence to be encoded. As a result, the internal bit discharging process at the end of the slice, tile, or code block sequence becomes unnecessary. It is possible to reduce the amount of generated codes by eliminating the process of discharging internal bits, and it is possible to suppress the deterioration of coding efficiency even when there are many slices, tiles, or code block sequences.

In addition, by increasing the types of context initial values, it is possible to suppress a decrease in coding efficiency when slice division, tile division, or WPP is used. More specifically, the initial value of the context has variations according to the context index. By switching the context index according to the input image, it is possible to use the symbol occurrence probability that better matches the image. As a result, the generated code amount can be suppressed even when the number of slices, tiles, or code block sequences is large, and the context learning efficiency cannot be improved.

The arithmetic engine initialization type flag makes it possible to switch the method for setting the initial values of the Range and Low positions, and it is possible to select a method with a small generated code amount according to the situation. This makes it possible to select one of the generated code amount due to the bit discharge processing inside the arithmetic encoder and the generated code amount when encoding the Range and Low positions, whichever has the smaller generated code amount. It is possible to improve the conversion efficiency.

FIG. 10 shows the syntax regarding the initial values of the context, the Range and the Low position. Here, first_syntax_element_in_independent_slice is a flag that becomes 1 when the target syntax element is the first syntax element in the independent slice segment. first_syntax_element_in_tile is a flag that becomes 1 when the target syntax element is the head syntax element of the tile. cabac_context_index indicates a context index. first_syntax_element_in_slice_segment is a flag that becomes 1 when the target syntax element is the first syntax element of a slice segment including independent/non-independent. first_syntax_element_in_left_block_WPP is a flag that becomes 1 when the target syntax element is the head syntax element of the leftmost code block of the screen at the time of WPP. init_cabac_engine_type_flag is an arithmetic engine initialization type flag. init_cabac_engine_range indicates a Range initial value. init_cabac_engine_low indicates a low position initial value. Descriptor represents a code string descriptor, ue represents an unsigned Golomb code, and u represents an unsigned integer value. The numerical value in the parentheses indicates the bit amount, and v indicates the variable length.

In the present embodiment, the arithmetic engine initialization is performed when the syntax element to be processed is the first syntax element of the slice segment or tile or the first syntax element of the leftmost code block of the screen at WPP. Although the type flag is encoded, the arithmetic engine initialization type flag is set once at the beginning of the picture or once at the beginning of the sequence, and the arithmetic engine initialization type flag is set for all slices, all tiles, or all code block strings. May be commonly used. By doing so, the number of times the arithmetic engine initialization type flag is coded can be reduced, so that the code amount can be reduced.

Further, in the above description, the image coding apparatus 100 uses the context of the upper right code block as the context initial value at the time of WPP, but this is not the only option, and the context of the upper code block or the code block at an arbitrary location is used. May be used. The coding efficiency can be improved by using the context of the code block having a high correlation with the code block to be coded.

Further, in the above description, the image encoding apparatus 100 Golomb-encodes the context index, the Range initial value, and the Low position initial value in S143 of FIG. 5 and S158 and S159 of FIG. 6, but other encoding methods may be used. It may be used, for example, it may be encoded with a fixed length. Further, the image coding apparatus 100 may code the difference from a specific value. For example, the image coding apparatus 100 may code a numerical value obtained by subtracting the Range initial value from “510”. The image coding apparatus 100 may set a specific value to be subtracted in a picture unit, a slice unit, or a tile unit, or may use a prediction unit to obtain a context index, a Range initial value, and a Low. The position initial value may be predicted and the predicted value may be set to a specific value to be subtracted. By doing so, the data to be encoded can be biased, so that the data with high occurrence frequency can be encoded with a short code length.

Further, in the above description, the image coding apparatus 100 sets the storage context to the context initial value at the time of WPP or in the case of a non-independent slice segment, but using the context index similarly to the independent slice segment or tile. The context initial value may be set. If the correlation between the code block or slice segment at the upper right of the copy target and the code block of the coding target is different, the coding efficiency can be improved by doing so.

Further, the processing in this embodiment may be realized by software. Then, this software may be distributed by downloading or the like. Also, this software may be recorded in a recording medium such as a CD-ROM and distributed. Note that this also applies to other embodiments in this specification.

(Embodiment 2)
<Overall structure>
FIG. 11 is a block diagram showing the configuration of image decoding apparatus 200 in the present embodiment. The image decoding device 200 shown in FIG. 11 includes a variable length decoding unit 201, an inverse conversion unit 202, an addition unit 203, a decoding block combination unit 204, and a frame memory 205.

<Operation (overall)>
Next, the flow of the entire decoding process will be described with reference to FIG.

First, the variable length decoding unit 201 acquires a frequency-converted code block by performing variable length decoding on a code string (S211).

Next, the inverse transform unit 202 generates a decoded difference block by inverse frequency transforming the frequency-transformed code block (S212). The addition unit 203 generates a decoded block by adding the decoded difference block and the motion compensation block (S213). The image decoding apparatus 200 repeats S211 to S213 until the decoding of all code blocks in the image to be decoded is completed (S214).

Next, the decoding block combination unit 204 decodes the image by combining the decoding blocks in the decoding target image (S215). Further, the obtained image and decoded block are stored in the frame memory 205.

Hereinafter, the characteristic variable length decoding unit 201 will be described in detail.

<Configuration of variable length decoding unit 201>
FIG. 13 is a block diagram showing the internal configuration of the variable length decoding unit 201. As shown in FIG. 13, the variable length decoding unit 201 includes a Golomb decoding unit 211, an arithmetic decoder initial value setting unit 212, an arithmetic decoding unit 213, a context storage unit 214, a context initial value setting unit 215, and a multi-value decoding unit. And a digitization unit 216.

<Variable length decoding process>
Next, the variable length decoding process will be described with reference to FIG.

First, the context initial value setting unit 215 sets the initial value of the context used during arithmetic decoding (S231). The arithmetic decoder initial value setting unit 212 sets the initial value of Range and the initial value of the Low position used at the time of arithmetic decoding (S232).

Next, the arithmetic decoding unit 213 generates a binary signal by arithmetically decoding the code string (S233). The multi-level conversion unit 216 acquires the syntax element that is a multi-level signal from the binary signal (S234). The arithmetic decoding unit 213 updates, normalizes, and acquires bits in Range, Low position, and context in arithmetic decoding.

Next, the context storage unit 214 stores the updated context (S235).

The variable length decoding unit 201 repeats S231 to S235 until the decoding of all syntax elements in the code block is completed (S236).

The characteristic context initial value setting process (S231) and the arithmetic decoder initial value setting process (S232) will be described in detail below. Note that the context storage process (S235) is the same as the context storage process of the first embodiment, so description will be omitted.

<Context initial value setting process>
The context initial value setting process (S231) will be described with reference to FIG.

When the syntax element to be processed is the first syntax element of the independent slice segment or tile (Yes in S241), the Golomb decoding unit 211 decodes the context index by Golomb decoding (S242). The context initial value setting unit 215 sets a value corresponding to the context index in the arithmetic decoding unit 213 as a context initial value (S243).

On the other hand, when the syntax element to be processed is the first syntax element of the leftmost code block of the screen at the time of WPP (Yes in S244) or the first syntax element of the non-independent slice segment (Yes in S245). ), the context initial value setting unit 215 sets the storage context stored in the context storage unit as the context initial value in the arithmetic decoding unit 213 (S246).

<Arithmetic decoder initial value setting processing>
The arithmetic decoder initial value setting process (S232) will be described with reference to FIG.

When the syntax element to be processed is the first syntax element of the slice segment or tile (Yes in S251), or the first syntax element of the screen leftmost code block at the time of WPP (Yes in S252), The arithmetic decoder initial value setting unit 212 acquires the arithmetic engine initialization type flag from the code string (S253). Here, the slice segment includes both independent and non-independent slice segments.

Next, when the arithmetic engine initialization type flag is “0” (Yes in S254), the arithmetic decoder initial value setting unit 212 uses “510” as the Range initial value and “0” as the Low position initial value. It sets in the decoding part 213 (S255 and S256). That is, the arithmetic decoder initial value setting unit 212 sets the fixed value as the initial value of the Range and Low positions.

When the arithmetic engine initialization type flag is "1" (No in S254), the Golomb decoding unit 211 Golomb-decodes the Range initial value and the Low position initial value (S257 and S258). The arithmetic decoder initial value setting unit 212 sets the Range initial value and the Low position initial value in the arithmetic decoding unit 213 (S259 and S260).

<Effect>
As described above, the image decoding device 200 according to the present embodiment can achieve the same effects as those of the first embodiment.

Although the image coding method and the image decoding method according to the embodiment have been described above, the present invention is not limited to this embodiment.

Further, each processing unit included in the image encoding device and the image decoding device according to the above embodiments is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.

Further, the integrated circuit is not limited to the LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure connection and settings of circuit cells inside the LSI may be used.

In each of the above-described embodiments, each component may be configured by dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded in a recording medium such as a hard disk or a semiconductor memory.

In other words, the image encoding device and the image decoding device include a processing circuit and a storage device electrically connected to the processing circuit (accessible from the processing circuit). The processing circuit includes at least one of dedicated hardware and a program execution unit. Further, when the processing circuit includes a program execution unit, the storage device stores the software program executed by the program execution unit. The processing circuit uses the storage device to execute the image encoding method or the image decoding method according to the above-described embodiment.

Further, the present invention may be the above software program or a non-transitory computer-readable recording medium in which the above program is recorded. Needless to say, the above program can be distributed via a transmission medium such as the Internet.

Further, all the numbers used above are examples for specifically explaining the present invention, and the present invention is not limited to the exemplified numbers.

Also, the division of functional blocks in the block diagram is an example, and multiple functional blocks are realized as one functional block, one functional block is divided into multiple, and some functions are moved to other functional blocks. May be. Further, the functions of a plurality of functional blocks having similar functions may be processed in parallel or in time division by a single piece of hardware or software.

Further, the order in which the steps included in the predictive image generation method, the encoding method, or the decoding method described above are executed for the purpose of specifically describing the present invention, and may be other than the order described above. May be. In addition, some of the above steps may be executed simultaneously (in parallel) with other steps.

The processing described in each embodiment may be realized by centralized processing using a single device (system), or may be realized by distributed processing using a plurality of devices. Good. Moreover, the computer that executes the program may be a single computer or a plurality of computers. That is, centralized processing may be performed or distributed processing may be performed.

Although the prediction image generation device, the encoding device, and the decoding device according to one or more aspects of the present invention have been described above based on the embodiment, the present invention is not limited to this embodiment. Absent. As long as it does not depart from the spirit of the present invention, various modifications made by those skilled in the art may be applied to the present embodiment, or a configuration constructed by combining components in different embodiments may be one or more of the present invention. It may be included in the range of the aspect.

(Embodiment 3)
By recording a program for realizing the configuration of the moving picture coding method (picture coding method) or the moving picture decoding method (picture decoding method) shown in each of the above embodiments in a storage medium, each of the above embodiments can be performed. It is possible to easily carry out the processing shown in the above form in an independent computer system. The storage medium may be a magnetic disk, an optical disk, a magneto-optical disk, an IC card, a semiconductor memory, or any other medium capable of recording a program.

Further, application examples of the moving picture coding method (picture coding method) and the moving picture decoding method (picture decoding method) shown in each of the above-described embodiments and a system using the same will be described. The system is characterized by having an image encoding/decoding device including an image encoding device using the image encoding method and an image decoding device using the image decoding method. Other configurations in the system can be appropriately changed depending on the case.

FIG. 17 is a diagram showing the overall configuration of a content supply system ex100 that realizes a content distribution service. A communication service providing area is divided into desired sizes, and base stations ex106, ex107, ex108, ex109, and ex110, which are fixed wireless stations, are installed in each cell.

This content supply system ex100 includes a computer ex111, a PDA (Personal Digital Assistant) ex112, a camera ex113, a mobile phone ex114, and a game machine ex115 via the Internet ex101 via an Internet service provider ex102, a telephone network ex104, and base stations ex106 to ex110. Each device such as is connected.

However, the content supply system ex100 is not limited to the configuration shown in FIG. 17, and any element may be combined and connected. Also, each device may be directly connected to the telephone network ex104 without going through the base stations ex106 to ex110 which are fixed wireless stations. In addition, the devices may be directly connected to each other via short-range wireless communication or the like.

The camera ex113 is a device such as a digital video camera capable of shooting moving images, and the camera ex116 is a device such as a digital camera capable of shooting still images and moving images. In addition, the mobile phone ex114 has a GSM (registered trademark) (Global System for Mobile Communications) system, a CDMA (Code Division Multiple Access) system, a W-CDMA (Wideband-Code Division Multiple Access) system, or an LTE (Long Term Evolution) system. System, HSPA (High Speed Packet Access) mobile phone, PHS (Personal Handyphone System), or the like.

In the content supply system ex100, the camera ex113 and the like are connected to the streaming server ex103 through the base station ex109 and the telephone network ex104, so that live distribution and the like can be performed. In the live distribution, the encoding process is performed as described in each of the above embodiments on the content (for example, the image of the live music) that the user shoots with the camera ex113 (that is, according to one embodiment of the present invention. (Functions as the image encoding device), and transmits to the streaming server ex103. On the other hand, the streaming server ex103 streams the content data transmitted to the requesting client. Examples of clients include a computer ex111, a PDA ex112, a camera ex113, a mobile phone ex114, a game console ex115, and the like that can decode the encoded data. Each device that receives the distributed data decodes and plays the received data (that is, functions as an image decoding device according to one aspect of the present invention).

The captured data may be coded by the camera ex113, the streaming server ex103 that performs the data transmission process, or the coding processes may be shared. Similarly, the decoding process of the distributed data may be performed by the client, the streaming server ex103, or the processes shared by the clients. Further, not limited to the camera ex113, still images and/or moving image data captured by the camera ex116 may be transmitted to the streaming server ex103 via the computer ex111. The encoding process in this case may be performed by any of the camera ex116, the computer ex111, and the streaming server ex103, or may be shared by the other.

Further, these encoding/decoding processes are generally processed by the computer ex111 and the LSI ex500 included in each device. The LSI ex500 may be a single chip or may be configured by a plurality of chips. It should be noted that the moving picture coding/decoding software is installed in some recording medium (CD-ROM, flexible disk, hard disk, etc.) that can be read by the computer ex111 and the like, and the coding/decoding processing is performed using the software. May be. Furthermore, when the mobile phone ex114 has a camera, the moving image data acquired by the camera may be transmitted. The moving image data at this time is data encoded by the LSI ex500 included in the mobile phone ex114.

Further, the streaming server ex103 may be a plurality of servers or a plurality of computers, and may decentralize data for processing, recording, or distributing.

As described above, in the content supply system ex100, the client can receive and reproduce the encoded data. As described above, in the content supply system ex100, the client can receive, decode, and reproduce the information transmitted by the user in real time, and a user who does not have a special right or facility can realize personal broadcasting.

Note that not only the example of the content supply system ex100, but also the digital broadcasting system ex200, as shown in FIG. 18, at least the moving image encoding device (image encoding device) or the moving image decoding device according to each of the above embodiments. Any of the devices (image decoding device) can be incorporated. Specifically, in the broadcast station ex201, multiplexed data in which music data and the like are multiplexed with video data is communicated or transmitted to the satellite ex202 via radio waves. This video data is data encoded by the moving image encoding method described in each of the above-described embodiments (that is, data encoded by the image encoding device according to one aspect of the present invention). Receiving this, the broadcasting satellite ex202 emits a radio wave for broadcasting, and the antenna ex204 of the home capable of receiving the satellite broadcast receives this radio wave. The received multiplexed data is decoded and reproduced by a device such as a television (receiver) ex300 or a set top box (STB) ex217 (that is, functions as an image decoding device according to one embodiment of the present invention).

In addition, a reader/recorder ex218 that reads and decodes multiplexed data recorded on a recording medium ex215 such as a DVD or a BD, or encodes a video signal on the recording medium ex215, and in some cases, writes the multiplexed signal together with a music signal. The moving picture decoding apparatus or the moving picture coding apparatus shown in each of the above embodiments can be mounted. In this case, the reproduced video signal is displayed on the monitor ex219, and the video signal can be reproduced in another device or system by the recording medium ex215 in which the multiplexed data is recorded. Further, the moving picture decoding apparatus may be mounted in the set top box ex217 connected to the cable ex203 for cable television or the antenna ex204 for satellite/terrestrial broadcasting, and this may be displayed on the monitor ex219 of the television. At this time, the moving picture decoding apparatus may be incorporated in the television instead of the set top box.

FIG. 19 is a diagram showing a television (receiver) ex300 using the moving picture decoding method and the moving picture coding method described in the above embodiments. The television ex300 obtains or outputs the multiplexed data in which the audio data is multiplexed with the video data via the antenna ex204 or the cable ex203 for receiving the broadcast, and the tuner ex301, and demodulates the received multiplexed data, Alternatively, a modulation/demodulation unit ex302 that modulates the multiplexed data to be transmitted to the outside, and the demodulated multiplexed data is separated into video data and audio data, or video data and audio data encoded by the signal processing unit ex306. And a multiplexing/demultiplexing unit ex303 for multiplexing.

In addition, the television ex300 includes an audio signal processing unit ex304 and a video signal processing unit ex305 that decode audio data and video data, respectively, or code the respective information (the image coding device or the image according to one embodiment of the present invention). A signal processing unit ex306 having a function as a decoding device), a speaker ex307 for outputting a decoded audio signal, and an output unit ex309 having a display unit ex308 such as a display for displaying the decoded video signal. Furthermore, the television ex300 has an interface unit ex317 having an operation input unit ex312 and the like for receiving an input of a user operation. Further, the television ex300 includes a control unit ex310 that controls each unit in an integrated manner, and a power supply circuit unit ex311 that supplies electric power to each unit. The interface unit ex317 is, in addition to the operation input unit ex312, a bridge unit ex313 connected to an external device such as a reader/recorder ex218, a slot unit ex314 for mounting a recording medium ex216 such as an SD card, and an external recording such as a hard disk. It may have a driver ex315 for connecting to a medium, a modem ex316 for connecting to a telephone network, and the like. Note that the recording medium ex216 is capable of electrically recording information by a non-volatile/volatile semiconductor memory element that stores the information. The respective units of the television ex300 are connected to each other via a synchronous bus.

First, a configuration in which the television ex300 decodes and reproduces multiplexed data acquired from the outside by the antenna ex204 or the like will be described. The television ex300 receives a user operation from the remote controller ex220 and the like, and under the control of the control unit ex310 having a CPU and the like, the multiplexing/demultiplexing unit ex303 separates the multiplexed data demodulated by the modulation/demodulation unit ex302. Further, in the television ex300, the separated audio data is decoded by the audio signal processing unit ex304, and the separated video data is decoded by the video signal processing unit ex305 using the decoding method described in each of the above embodiments. The decoded audio signal and video signal are output from the output unit ex309 to the outside. When outputting, these signals may be temporarily stored in the buffers ex318, ex319, etc. so that the audio signals and the video signals are reproduced in synchronization. Further, the television ex300 may read the multiplexed data from the recording media ex215 and ex216 such as a magnetic/optical disk and an SD card, not from broadcasting or the like. Next, a configuration in which the television ex300 encodes an audio signal or a video signal and transmits the signal externally or writes the signal on a recording medium will be described. The television ex300 receives a user operation from the remote controller ex220 or the like, and under the control of the control unit ex310, the audio signal processing unit ex304 encodes the audio signal, and the video signal processing unit ex305 converts the video signal into the above-described embodiments. Encoding is performed using the encoding method described in. The encoded audio signal and video signal are multiplexed by the multiplexer/demultiplexer ex303 and output to the outside. When multiplexing, these signals may be temporarily stored in the buffers ex320 and ex321 so that the audio signals and the video signals are synchronized. Note that a plurality of buffers ex318, ex319, ex320, and ex321 may be provided as illustrated, or one or more buffers may be shared. Further, other than the illustrated one, data may be stored in the buffer as a buffer material for avoiding system overflow and underflow, for example, between the modulation/demodulation unit ex302 and the multiplexing/demultiplexing unit ex303.

In addition, the television ex300 has a configuration for receiving AV input of a microphone or a camera, in addition to acquiring audio data and video data from broadcasting or recording media, and performs an encoding process on the data acquired from them. Good. Note that, here, the television ex300 has been described as a configuration capable of the above-described encoding processing, multiplexing, and external output, but these processing cannot be performed, and only the above-described reception, decoding processing, and external output are possible. It may be configured.

When the reader/recorder ex218 reads or writes the multiplexed data from the recording medium, the decoding process or the encoding process may be performed by either the television ex300 or the reader/recorder ex218, or the television ex300. The reader/recorder ex218 may share the work with each other.

As an example, FIG. 20 shows the configuration of the information reproducing/recording unit ex400 when reading or writing data from the optical disc. The information reproducing/recording unit ex400 includes elements ex401, ex402, ex403, ex404, ex405, ex406, ex407 described below. The optical head ex401 irradiates a laser spot on the recording surface of the recording medium ex215, which is an optical disc, to write information, detects the reflected light from the recording surface of the recording medium ex215, and reads information. The modulation recording unit ex402 electrically drives a semiconductor laser incorporated in the optical head ex401 to modulate the laser light according to the recording data. The reproduction demodulation unit ex403 amplifies the reproduction signal obtained by electrically detecting the reflected light from the recording surface by the photodetector built in the optical head ex401, separates the signal component recorded in the recording medium ex215, and demodulates it. To reproduce the correct information. The buffer ex404 temporarily holds information to be recorded on the recording medium ex215 and information reproduced from the recording medium ex215. The disk motor ex405 rotates the recording medium ex215. The servo control unit ex406 moves the optical head ex401 to a predetermined information track while controlling the rotation drive of the disk motor ex405, and performs a laser spot tracking process. The system control unit ex407 controls the entire information reproducing/recording unit ex400. The system control unit ex407 uses the various types of information held in the buffer ex404 for the above-mentioned read/write processing, and also generates/adds new information as necessary, and also the modulation recording unit ex402 and the reproduction/demodulation unit. This is realized by recording/reproducing information through the optical head ex401 while operating the ex403 and the servo control unit ex406 in cooperation. The system control unit ex407 is composed of, for example, a microprocessor, and executes these processes by executing a read/write program.

Although the optical head ex401 has been described above as irradiating a laser spot, it may be configured to perform recording with higher density by using near-field light.

FIG. 21 shows a schematic diagram of a recording medium ex215 which is an optical disc. A guide groove (groove) is formed in a spiral shape on the recording surface of the recording medium ex215, and address information indicating an absolute position on the disc is recorded in advance on the information track ex230 due to a change in the shape of the groove. This address information includes information for specifying the position of the recording block ex231 which is a unit for recording data, and specifies the recording block by reproducing the information track ex230 and reading the address information in the device for recording or reproducing. You can The recording medium ex215 includes a data recording area ex233, an inner peripheral area ex232, and an outer peripheral area ex234. The area used for recording the user data is the data recording area ex233, and the inner peripheral area ex232 and the outer peripheral area ex234 arranged on the inner or outer circumference of the data recording area ex233 are used for a specific purpose other than the recording of the user data. Used. The information reproducing/recording unit ex400 reads/writes encoded audio data, video data, or multiplexed data obtained by multiplexing these data from/into the data recording area ex233 of the recording medium ex215.

In the above description, an optical disc such as a single-layer DVD or BD has been described as an example, but the optical disc is not limited to these and may be an optical disc that has a multi-layer structure and is capable of recording other than the surface. Also, an optical disc having a structure for performing multi-dimensional recording/reproduction, such as recording information on the same place of the disc by using lights of various different wavelengths or recording layers of different information from various angles. May be

Further, in the digital broadcasting system ex200, it is also possible for a car ex210 having an antenna ex205 to receive data from a satellite ex202 or the like and reproduce a moving image on a display device such as a car navigation ex211 included in the car ex210. Note that the configuration of the car navigation ex211 may be, for example, a configuration including a GPS receiving unit in the configuration shown in FIG. 19, and the same may be considered in the computer ex111, the mobile phone ex114, or the like.

FIG. 22A is a diagram showing a mobile phone ex114 that uses the moving picture decoding method and the moving picture coding method described in the above embodiments. The mobile phone ex114 has an antenna ex350 for transmitting and receiving radio waves to and from the base station ex110, a camera unit ex365 that can take a video image and a still image, an image captured by the camera unit ex365, an image received by the antenna ex350, and the like. Is provided with a display unit ex358 such as a liquid crystal display for displaying the decoded data. The mobile phone ex114 further includes a main body unit having an operation key unit ex366, a voice output unit ex357 that is a speaker for outputting voice, a voice input unit ex356 that is a microphone for inputting voice, a captured image, A memory unit ex367 for storing encoded data or decoded data such as a still image, recorded voice, or received video, still image, mail, or the like, or an interface unit with a recording medium for storing data. A certain slot part ex364 is provided.

Furthermore, a configuration example of the mobile phone ex114 will be described with reference to FIG. 22B. The mobile phone ex114 has a power supply circuit unit ex361, an operation input control unit ex362, and a video signal processing unit ex355 with respect to a main control unit ex360 that integrally controls each unit of the main body including a display unit ex358 and an operation key unit ex366. The camera interface unit ex363, the LCD (Liquid Crystal Display) control unit ex359, the modulation/demodulation unit ex352, the multiplexing/demultiplexing unit ex353, the audio signal processing unit ex354, the slot unit ex364, and the memory unit ex367 are connected to each other via a bus ex370. ing.

When the call ends and the power key is turned on by the user's operation, the power supply circuit unit ex361 activates the mobile phone ex114 by supplying power from the battery pack to each unit.

The mobile phone ex114 converts the audio signal picked up by the audio input unit ex356 in the audio call mode into a digital audio signal by the audio signal processing unit ex354, under the control of the main control unit ex360 having a CPU, a ROM, a RAM, and the like. The modulation/demodulation unit ex352 performs spread spectrum processing on this, and the transmission/reception unit ex351 performs digital-analog conversion processing and frequency conversion processing, and then transmits via the antenna ex350. In addition, the mobile phone ex114 amplifies the received data received through the antenna ex350 in the voice call mode, performs frequency conversion processing and analog-digital conversion processing, performs spectrum despreading processing in the modulation/demodulation unit ex352, and performs voice signal processing unit. After being converted into an analog audio signal in ex354, this is output from the audio output unit ex357.

Furthermore, when sending an electronic mail in the data communication mode, the text data of the electronic mail input by operating the operation key unit ex366 of the main body unit is sent to the main control unit ex360 via the operation input control unit ex362. The main control unit ex360 transmits the text data to the base station ex110 via the antenna ex350 after the modulation/demodulation unit ex352 performs spread spectrum processing and the transmission/reception unit ex351 performs digital/analog conversion processing and frequency conversion processing. .. When receiving an e-mail, the received data is subjected to almost the opposite process and output to the display unit ex358.

When transmitting video, still image, or video and audio in the data communication mode, the video signal processing unit ex355 compresses the video signal supplied from the camera unit ex365 by the moving image coding method described in each of the above embodiments. The encoded video data is encoded (that is, functions as the image encoding device according to an aspect of the present invention), and the encoded video data is sent to the multiplexing/demultiplexing unit ex353. Further, the audio signal processing unit ex354 encodes the audio signal picked up by the audio input unit ex356 while the video unit, the still image, and the like are being captured by the camera unit ex365, and sends the encoded audio data to the multiplexing/demultiplexing unit ex353. To do.

The multiplexing/demultiplexing unit ex353 multiplexes the coded video data supplied from the video signal processing unit ex355 and the coded audio data supplied from the audio signal processing unit ex354 by a predetermined method, and the result is obtained. Modulation/demodulation unit (modulation/demodulation circuit unit) ex352 performs spread spectrum processing on the multiplexed data, and transmission/reception unit ex351 performs digital-analog conversion processing and frequency conversion processing, and then transmits the data via antenna ex350.

Decode the multiplexed data received via the antenna ex350 when receiving the data of the moving image file linked to the homepage or the like in the data communication mode or when receiving the e-mail with the attached video and/or audio. In order to do so, the demultiplexing/demultiplexing unit ex353 separates the multiplexed data into a bit stream of video data and a bit stream of audio data, and processes the encoded video data via the synchronous bus ex370. In addition to supplying to the unit ex355, the encoded audio data is supplied to the audio signal processing unit ex354. The video signal processing unit ex355 decodes the video signal by performing decoding by the moving picture decoding method corresponding to the moving picture coding method described in each of the above-described embodiments (that is, the image according to one embodiment of the present invention). The display unit ex358 displays, via the LCD control unit ex359, a video image or a still image included in a moving image file linked to a home page, for example. Further, the audio signal processing unit ex354 decodes the audio signal and the audio output unit ex357 outputs the audio.

Further, the terminal such as the mobile phone ex114 is a transmission/reception terminal having both encoders/decoders, as well as the television ex300, as well as a transmission terminal having only an encoder and a receiving terminal having only a decoder. There are three possible implementation formats. Further, in the digital broadcasting system ex200, it has been described that the multiplexed data in which the music data and the like are multiplexed in the video data is received and transmitted, but the data in which the character data and the like related to the video are multiplexed in addition to the audio data. Or the video data itself may be used instead of the multiplexed data.

As described above, it is possible to use the moving picture coding method or the moving picture decoding method shown in each of the above-described embodiments in any of the above-described devices and systems, and by doing so, in each of the above-described embodiments, The effect described can be obtained.

Further, the present invention is not limited to the above-described embodiment, and various changes or modifications can be made without departing from the scope of the present invention.

(Embodiment 4)
The moving picture coding method or device shown in each of the above embodiments and the moving picture coding method or device conforming to different standards such as MPEG-2, MPEG4-AVC, and VC-1 are appropriately switched as necessary. By doing so, it is possible to generate video data.

Here, when a plurality of video data conforming to different standards are generated, when decoding, it is necessary to select a decoding method corresponding to each standard. However, since it is not possible to identify which standard the video data to be decoded complies with, a problem arises in that an appropriate decoding method cannot be selected.

In order to solve this problem, multiplexed data obtained by multiplexing audio data and the like on video data includes identification information indicating which standard the video data complies with. A specific configuration of multiplexed data including video data generated by the moving picture coding method or apparatus shown in each of the above embodiments will be described below. The multiplexed data is a digital stream in the MPEG-2 transport stream format.

FIG. 23 is a diagram showing the structure of multiplexed data. As shown in FIG. 23, the multiplexed data can be obtained by multiplexing at least one of a video stream, an audio stream, a presentation graphics stream (PG), and an interactive graphics stream. The video stream indicates the main video and sub-video of the movie, the audio stream (IG) indicates the main audio part of the movie and the sub-audio that mixes with the main audio, and the presentation graphics stream indicates the subtitle of the movie. Here, the main video refers to a normal video displayed on the screen, and the sub video refers to a video displayed on the small screen in the main video. The interactive graphics stream indicates an interactive screen created by arranging GUI parts on the screen. The video stream is encoded by the moving picture coding method or apparatus shown in each of the above-described embodiments and the moving picture coding method or apparatus conforming to the standards such as the conventional MPEG-2, MPEG4-AVC, VC-1 and the like. ing. The audio stream is encoded by a method such as Dolby AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, or linear PCM.

Each stream included in the multiplexed data is identified by PID. For example, 0x1011 is used for a video stream used for movie images, 0x1100 to 0x111F is used for an audio stream, 0x1200 to 0x121F is used for presentation graphics, and 0x1400 to 0x141F is used for an interactive graphics stream. 0x1B00 to 0x1B1F are assigned to the video stream used for the sub video, and 0x1A00 to 0x1A1F are assigned to the audio stream used for the sub audio mixed with the main audio.

FIG. 24 is a diagram schematically showing how multiplexed data is multiplexed. First, the video stream ex235 including a plurality of video frames and the audio stream ex238 including a plurality of audio frames are converted into PES packet strings ex236 and ex239, respectively, and converted into TS packets ex237 and ex240. Similarly, the data of the presentation graphics stream ex241 and the data of the interactive graphics ex244 are converted into PES packet strings ex242 and ex245, respectively, and further converted into TS packets ex243 and ex246. The multiplexed data ex247 is configured by multiplexing these TS packets into one stream.

FIG. 25 shows in more detail how the video stream is stored in the PES packet sequence. The first row in FIG. 25 shows a video frame sequence of a video stream. The second row shows the PES packet sequence. As shown by arrows yy1, yy2, yy3, and yy4 in FIG. 25, a plurality of Video Presentation Units of I picture, B picture, and P picture in the video stream are divided for each picture and stored in the payload of the PES packet. .. Each PES packet has a PES header, and the PES header stores PTS (Presentation Time-Stamp) which is the display time of the picture and DTS (Decoding Time-Stamp) which is the decoding time of the picture.

FIG. 26 shows the format of TS packets finally written in the multiplexed data. The TS packet is a 188-byte fixed-length packet composed of a 4-byte TS header having information such as PID for identifying a stream and a 184-byte TS payload storing data. The PES packet is divided and stored in the TS payload. It In the case of BD-ROM, TP_Extra_Header of 4 bytes is added to the TS packet to form a source packet of 192 bytes, which is written in the multiplexed data. Information such as ATS (Arrival_Time_Stamp) is described in TP_Extra_Header. ATS indicates the transfer start time of the TS packet to the PID filter of the decoder. Source packets are arranged in the multiplexed data as shown in the lower part of FIG. 26, and the number incremented from the beginning of the multiplexed data is called SPN (source packet number).

The TS packets included in the multiplexed data include PAT (Program Association Table), PMT (Program Map Table), PCR (Program Clock Reference), and the like, in addition to streams such as video, audio, and subtitles. The PAT indicates what the PID of the PMT used in the multiplexed data is, and the PID of the PAT itself is registered as 0. The PMT has PID of each stream such as video/audio/caption included in the multiplexed data and attribute information of the stream corresponding to each PID, and also has various descriptors related to the multiplexed data. The descriptor includes copy control information for instructing permission/prohibition of copying of multiplexed data. The PCR corresponds to the ATS whose PCR packet is transferred to the decoder in order to synchronize the ATC (Arrival Time Clock) which is the time axis of the ATS and the STC (System Time Clock) which is the time axis of the PTS/DTS. Holds STC time information.

FIG. 27 is a diagram for explaining the data structure of the PMT in detail. At the beginning of the PMT, a PMT header describing the length of data included in the PMT and the like is arranged. Behind it, a plurality of descriptors regarding multiplexed data are arranged. The copy control information and the like are described as descriptors. A plurality of stream information regarding each stream included in the multiplexed data is arranged after the descriptor. The stream information is composed of a stream type, a stream PID for identifying a compression codec of the stream, and a stream descriptor in which stream attribute information (frame rate, aspect ratio, etc.) is described. There are as many stream descriptors as there are streams in the multiplexed data.

When recorded on a recording medium or the like, the multiplexed data is recorded together with the multiplexed data information file.

The multiplexed data information file is management information of multiplexed data as shown in FIG. 28, and corresponds to the multiplexed data in a one-to-one correspondence, and is composed of multiplexed data information, stream attribute information, and an entry map.

As shown in FIG. 28, the multiplexed data information includes a system rate, a reproduction start time, and a reproduction end time. The system rate indicates the maximum transfer rate of multiplexed data to the PID filter of the system target decoder described later. The interval between ATSs included in the multiplexed data is set to be equal to or lower than the system rate. The playback start time is the PTS of the first video frame of the multiplexed data, and the playback end time is set to the PTS of the video frame at the end of the multiplexed data plus the playback interval of one frame.

As shown in FIG. 29, as the stream attribute information, attribute information about each stream included in the multiplexed data is registered for each PID. The attribute information has different information for each video stream, audio stream, presentation graphics stream, and interactive graphics stream. The video stream attribute information includes what kind of compression codec the video stream was compressed with, what is the resolution of each picture data that constitutes the video stream, what is the aspect ratio, and what is the frame rate. It has information such as how much it is. The audio stream attribute information includes what compression codec the audio stream was compressed with, what the number of channels included in the audio stream, what language it corresponds to, what sampling frequency, etc. With information. These pieces of information are used for initialization of the decoder before reproduction by the player.

In the present embodiment, of the multiplexed data, the stream type included in the PMT is used. When multiplexed data is recorded on the recording medium, the video stream attribute information included in the multiplexed data information is used. Specifically, in the moving picture coding method or apparatus shown in each of the above embodiments, the moving picture coding shown in each of the above embodiments is applied to the stream type included in the PMT or the video stream attribute information. There is provided a step or means for setting unique information indicating that the video data is generated by the method or apparatus. With this configuration, it is possible to distinguish between the video data generated by the moving picture coding method or apparatus shown in each of the above embodiments and the video data compliant with other standards.

Further, FIG. 30 shows steps of the moving picture decoding method according to the present embodiment. In step exS100, the stream type included in the PMT or the video stream attribute information included in the multiplexed data information is acquired from the multiplexed data. Next, in step exS101, it is determined whether or not the stream type or the video stream attribute information indicates that the data is multiplexed data generated by the moving picture coding method or apparatus described in each of the above embodiments. To do. If it is determined that the stream type or the video stream attribute information is generated by the moving picture coding method or apparatus described in each of the above embodiments, in step exS102, each of the above embodiments is performed. Decoding is performed by the moving picture decoding method shown in the form. If the stream type or the video stream attribute information indicates that the stream type or the video stream attribute information complies with the standard such as the conventional MPEG-2, MPEG4-AVC, or VC-1, in step exS103, the conventional Decoding is performed by a moving image decoding method that conforms to the standard.

In this way, by setting a new eigenvalue in the stream type or the video stream attribute information, it is possible to determine whether the moving image decoding method or device shown in each of the above embodiments can be used for decoding. You can judge. Therefore, even when multiplexed data conforming to different standards is input, an appropriate decoding method or device can be selected, and therefore decoding can be performed without causing an error. Further, the moving picture coding method or apparatus or the moving picture decoding method or apparatus shown in the present embodiment can be used in any of the above-described devices and systems.

(Embodiment 5)
The moving picture coding method and apparatus and the moving picture decoding method and apparatus shown in each of the above embodiments are typically realized by an LSI which is an integrated circuit. As an example, FIG. 31 illustrates a configuration of the LSI ex500 that is made into one chip. The LSI ex500 includes elements ex501, ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509, which are described below, and each element is connected via a bus ex510. The power supply circuit unit ex505 starts up in an operable state by supplying electric power to each unit when the power supply is on.

For example, when performing the encoding process, the LSI ex500 uses the AV I/O ex509 to control the microphone ex117 and the camera ex113 under the control of the control unit ex501 including the CPU ex502, the memory controller ex503, the stream controller ex504, and the drive frequency control unit ex512. AV signal is input from the above. The input AV signal is temporarily stored in an external memory ex511 such as SDRAM. Based on the control of the control unit ex501, the accumulated data is appropriately divided into a plurality of times according to the processing amount and the processing speed, and is sent to the signal processing unit ex507, and the signal processing unit ex507 encodes the audio signal and/or video. The signal is encoded. Here, the encoding process of the video signal is the encoding process described in each of the above embodiments. The signal processing unit ex507 further performs processing such as multiplexing encoded audio data and encoded video data, as the case may be, and outputs the stream I/O ex506 to the outside. The output multiplexed data is transmitted to the base station ex107 or written in the recording medium ex215. Note that data may be temporarily stored in the buffer ex508 so as to be synchronized when multiplexing.

Note that, in the above, the memory ex511 is described as a configuration outside the LSI ex500, but may be a configuration included inside the LSI ex500. The number of buffers ex508 is not limited to one, and a plurality of buffers may be provided. The LSI ex500 may be made into one chip or may be made into a plurality of chips.

In the above description, the control unit ex501 has the CPU ex502, the memory controller ex503, the stream controller ex504, the drive frequency control unit ex512, and the like, but the configuration of the control unit ex501 is not limited to this configuration. For example, the signal processing unit ex507 may further include a CPU. By providing a CPU inside the signal processing unit ex507 as well, the processing speed can be further improved. Further, as another example, the CPU ex502 may be configured to include a signal processing unit ex507 or an audio signal processing unit that is a part of the signal processing unit ex507. In such a case, the control unit ex501 is configured to include the signal processing unit ex507 or the CPU ex502 having a part thereof.

It should be noted that although the name used here is LSI, it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and it may be realized by a dedicated circuit or a general-purpose processor. A field programmable gate array (FPGA) that can be programmed after the LSI is manufactured, or a reconfigurable processor capable of reconfiguring the connection and setting of circuit cells inside the LSI may be used. Such a programmable logic device is typically loaded with a program constituting software or firmware or read from a memory or the like to thereby obtain the moving image coding method or moving image shown in each of the above embodiments. An image decoding method can be performed.

Furthermore, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. There is a possibility that biotechnology will be applied.

(Embodiment 6)
When decoding the video data generated by the moving picture coding method or apparatus shown in each of the above embodiments, the video data complying with the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1 are decoded. It is conceivable that the processing amount will increase as compared with the case. Therefore, in the LSI ex500, it is necessary to set the drive frequency higher than the drive frequency of the CPU ex502 when decoding the video data conforming to the conventional standard. However, when the driving frequency is increased, there is a problem that power consumption increases.

In order to solve this problem, the moving picture decoding apparatus such as the television ex300 and the LSI ex500 is configured to identify which standard the video data complies with and switch the drive frequency according to the standard. FIG. 32 shows a configuration ex800 in the present embodiment. The drive frequency switching unit ex803 sets the drive frequency high when the video data is generated by the moving picture coding method or apparatus shown in each of the above embodiments. Then, the decoding processing unit ex801 that executes the moving picture decoding method described in each of the above embodiments is instructed to decode the video data. On the other hand, when the video data is video data complying with the conventional standard, as compared with the case where the video data is generated by the moving picture coding method or device shown in each of the above embodiments, Set the drive frequency low. Then, the decoding processing unit ex802 conforming to the conventional standard is instructed to decode the video data.

More specifically, the drive frequency switching unit ex803 includes the CPU ex502 and the drive frequency control unit ex512 of FIG. Further, the decoding processing unit ex801 that executes the moving picture decoding method described in each of the above-described embodiments and the decoding processing unit ex802 that conforms to the conventional standard correspond to the signal processing unit ex507 in FIG. The CPU ex502 identifies which standard the video data complies with. Then, the drive frequency control unit ex512 sets the drive frequency based on the signal from the CPU ex502. Further, the signal processing unit ex507 decodes the video data based on the signal from the CPU ex502. Here, for identification of the video data, for example, the identification information described in the fourth embodiment may be used. The identification information is not limited to that described in the fourth embodiment, and may be any information as long as it can identify which standard the video data complies with. For example, it is possible to identify which standard the video data complies with based on an external signal that identifies whether the video data is used for a television or a disc. In some cases, identification may be performed based on such an external signal. Further, it is conceivable that the selection of the driving frequency in the CPU ex502 is performed based on, for example, a look-up table as shown in FIG. The lookup table can be stored in the buffer ex508 or the internal memory of the LSI, and the CPU ex502 can select the drive frequency by referring to the lookup table.

FIG. 33 shows steps for carrying out the method of the present embodiment. First, in step exS200, the signal processing unit ex507 acquires identification information from the multiplexed data. Next, in step exS201, the CPU ex502 discriminates based on the identification information whether or not the video data is generated by the encoding method or apparatus shown in each of the above embodiments. When the video data is generated by the encoding method or apparatus described in each of the above-described embodiments, in step exS202, the CPU ex502 sends a signal for setting a high drive frequency to the drive frequency control unit ex512. Then, the drive frequency control unit ex512 sets a high drive frequency. On the other hand, when the video data indicates that the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, in step exS203, the CPU ex502 drives a signal for setting the driving frequency low. It is sent to the frequency control unit ex512. Then, in the drive frequency control unit ex512, the drive frequency is set to be lower than that in the case where the video data is generated by the encoding method or apparatus described in each of the above embodiments.

Furthermore, the power saving effect can be further enhanced by changing the voltage applied to the LSI ex500 or a device including the LSI ex500 in conjunction with the switching of the drive frequency. For example, when the drive frequency is set low, the voltage applied to the LSI ex500 or a device including the LSI ex500 may be set lower accordingly as compared with the case where the drive frequency is set high.

Further, the method of setting the driving frequency may be such that when the processing amount for decoding is large, the driving frequency is set high, and when the processing amount for decoding is small, the driving frequency is set low. Not limited to the method. For example, when the processing amount for decoding the video data compliant with the MPEG4-AVC standard is larger than the processing amount for decoding the video data generated by the moving picture coding method or apparatus described in each of the above embodiments. For this, it is conceivable that the setting of the drive frequency is reversed from the case described above.

Furthermore, the method of setting the drive frequency is not limited to the configuration of lowering the drive frequency. For example, when the identification information indicates that it is video data generated by the moving picture coding method or apparatus described in each of the above-described embodiments, the voltage applied to the LSI ex500 or the apparatus including the LSI ex500 is set to be high. However, when it is shown that the video data is based on the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, it may be possible to set a low voltage to be applied to the LSI ex500 or a device including the LSI ex500. To be Further, as another example, when the identification information indicates that the video data is generated by the moving picture coding method or apparatus described in each of the above-described embodiments, the driving of the CPU ex502 is stopped. However, if it indicates that the video data complies with the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, the CPU ex502 must be temporarily stopped because there is enough processing. Can also be considered. Even if the identification information indicates that it is the video data generated by the moving picture coding method or apparatus described in each of the above embodiments, if there is a margin in the processing, the CPU ex502 is temporarily driven. It is possible to stop it. In this case, it is conceivable to set the stop time shorter than that in the case where it is shown that the video data complies with the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1.

In this way, it is possible to save power by switching the drive frequency according to the standard with which the video data complies. Further, when the LSI ex500 or a device including the LSI ex500 is driven by using a battery, it is possible to prolong the life of the battery due to power saving.

(Embodiment 7)
A plurality of video data conforming to different standards may be input to the above-mentioned devices and systems such as a television and a mobile phone. As described above, the signal processing unit ex507 of the LSI ex500 needs to be compatible with a plurality of standards in order to enable decoding even when a plurality of video data conforming to different standards are input. However, if the signal processing units ex507 corresponding to the respective standards are individually used, the circuit scale of the LSI ex500 becomes large and the cost increases.

In order to solve this problem, a decoding processing unit for executing the moving picture decoding method shown in each of the above-described embodiments, and decoding conforming to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. A part of the processing unit is shared. An example of this configuration is shown as ex900 in FIG. 35A. For example, the moving picture decoding method shown in each of the above embodiments and the moving picture decoding method conforming to the MPEG4-AVC standard are processed in processing such as entropy coding, dequantization, deblocking filter, and motion compensation. Some contents are common. For common processing contents, the decoding processing unit ex902 corresponding to the MPEG4-AVC standard is shared, and for other processing contents specific to one aspect of the present invention that do not correspond to the MPEG4-AVC standard, a dedicated decoding processing unit is used. A configuration using ex901 can be considered. In particular, one aspect of the present invention is characterized by entropy coding, and therefore, for example, a dedicated decoding processing unit ex901 is used for entropy coding, and other dequantization, deblocking filter, It is conceivable to share the decoding processing unit for any or all of the motion compensation processes. Regarding the common processing contents regarding the sharing of the decoding processing unit, the decoding processing unit for executing the moving picture decoding method shown in each of the above embodiments is shared, and the processing contents specific to the MPEG4-AVC standard. For, the configuration may be such that a dedicated decoding processing unit is used.

In addition, another example of partially sharing the processing is shown in ex1000 of FIG. 35B. In this example, a dedicated decoding processing unit ex1001 corresponding to the processing content specific to one aspect of the present invention, a dedicated decoding processing unit ex1002 corresponding to the processing content specific to another conventional standard, and one aspect of the present invention The common decoding processing unit ex1003 corresponding to the processing content common to the moving picture decoding method according to the present invention and the moving picture decoding method according to another conventional standard is used. Here, the dedicated decoding processing units ex1001 and ex1002 are not necessarily specialized to the processing contents specific to one aspect of the present invention or other conventional standards, and can execute other general-purpose processing. Good. Further, the configuration of this embodiment can be mounted on the LSI ex500.

As described above, by sharing the decoding processing unit with respect to the processing content common to the moving image decoding method according to one aspect of the present invention and the conventional standard moving image decoding method, the circuit scale of the LSI is reduced, In addition, it is possible to reduce the cost.

The present invention can be applied to an image processing device, an image capturing device, and an image reproducing device. Specifically, the present invention can be applied to a digital still camera, a movie, a mobile phone with a camera function, a smartphone, and the like.

100 image coding apparatus 101 code block division unit 102 subtraction unit 103 conversion unit 104 variable length coding unit 105 inverse conversion unit 106 addition unit 107 frame memory 108 prediction unit 111 binarization unit 112 arithmetic coding unit 113 context storage unit 114 Context initial value setting unit 115 Arithmetic encoder data storage unit 116 Arithmetic encoder initial value setting unit 117 Golomb encoding unit 200 Image decoding device 201 Variable length decoding unit 202 Inverse conversion unit 203 Adder unit 204 Decoding block combining unit 205 frames Memory 211 Golomb decoding unit 212 Arithmetic decoder initial value setting unit 213 Arithmetic decoding unit 214 Context storage unit 215 Context initial value setting unit 216 Multivalued unit

Claims (6)

An image coding method for performing arithmetic coding on an image signal, comprising:
An encoding step of encoding information for deriving at least one of a Range indicating a section used for the arithmetic encoding and a Low position indicating a minimum position of the section;
At the start of arithmetic encoding of the image signal, including an initialization step of performing initialization of the arithmetic encoding based on the information,
The information is a mode for setting an initial value of at least one of the Range and the Low position by a predetermined fixed value, and an initial value of at least one of the Range and the Low position based on information in a code string. Includes a flag to switch between setting mode and
The image encoding method, wherein in the initialization step, the initialization is performed using a mode designated by the flag. The information includes an index that specifies one of a plurality of initial value sets for the context,
The image encoding method according to claim 1, wherein in the initialization step, the initialization is performed using a set of initial values specified by the index. An image decoding method for performing arithmetic decoding on a bitstream generated by encoding an image,
A decoding step of decoding information for deriving at least one of a Range indicating a section used for the arithmetic decoding and a Low position indicating a minimum position of the section;
At the start of arithmetic decoding of the bitstream, including an initialization step of initializing the arithmetic decoding based on the information,
The information is a mode for setting an initial value of at least one of the Range and the Low position by a predetermined fixed value, and an initial value of at least one of the Range and the Low position based on information in a code string. Includes a flag to switch between setting mode and
The image decoding method, wherein in the initialization step, the initialization is performed using a mode designated by the flag. The information includes an index that specifies one of a plurality of initial value sets for the context,
The image decoding method according to claim 3, wherein in the initialization step, the initialization is performed using a set of initial values specified by the index. An image encoding device for performing arithmetic encoding on an image signal, comprising:
An encoding unit that encodes information for deriving at least one of a Range indicating a section used for the arithmetic encoding and a Low position indicating a minimum position of the section,
At the start of arithmetic coding of the image signal, an initialization unit that initializes the arithmetic coding based on the information,
The information is a mode for setting an initial value of at least one of the Range and the Low position by a predetermined fixed value, and an initial value of at least one of the Range and the Low position based on information in a code string. Includes a flag to switch between setting mode and
The image encoding device, wherein the initialization unit performs the initialization using a mode designated by the flag. An image decoding device for performing arithmetic decoding on a bitstream generated by encoding an image,
A decoding unit that decodes information for deriving at least one of a Range indicating a section used for the arithmetic decoding and a Low position indicating a minimum position of the section;
At the start of arithmetic decoding of the bitstream, an initialization unit that initializes the arithmetic decoding based on the information,
The information is a mode for setting an initial value of at least one of the Range and the Low position by a predetermined fixed value, and an initial value of at least one of the Range and the Low position based on information in a code string. Includes a flag to switch between setting mode and
The image decoding device, wherein the initialization unit performs the initialization using a mode designated by the flag.

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