WO2012102023A1

WO2012102023A1 - Decoding method and encoding method

Info

Publication number: WO2012102023A1
Application number: PCT/JP2012/000428
Authority: WO
Inventors: 陽司柴原; 西　孝啓; 寿郎笹井; 敏康杉尾
Original assignee: パナソニック株式会社
Priority date: 2011-01-26
Filing date: 2012-01-24
Publication date: 2012-08-02

Abstract

A decoding method with which the amount of calculation can be reduced involves: a step (S208) of performing entropy decoding and generating a plurality of quantization coefficients; a step (S209) of dequantizing the plurality of quantization coefficients and generating a decoding-transformation output; a step (S204) of performing a second inverse transformation with respect to a second decode transformation output that constitutes a portion of said decoding-transformation output; a step (S207) of performing, by a single operation, a first inverse transformation with respect to said second decode transformation output, which has been subjected to said second inverse transformation, and a second decode portion which is a portion that was not subjected to said second inverse transformation; and a control step (S210) of controlling, on a block-by-block basis and in accordance with the bit length of the decoding-transformation output, the shift amount obtained after the matrix multiplication of the transformation coefficient for the second inverse transformation in a manner such that the maximum bit length of internal variables necessary for the matrix multiplication of said first inverse transformation does not exceed a predetermined value.

Description

Decoding method and encoding method

The present invention relates to audio encoding and decoding, still image encoding and decoding, or moving image encoding and decoding, and more particularly, to a method of converting a space-time domain signal vector to a frequency domain, and the like. .

In order to compress voice data and moving picture data, a plurality of voice coding standards and moving picture coding standards have been developed. As an example of the video coding standard, H.264 ITU-T standard called 26x and ISO / IEC standard called MPEG-x. The latest video coding standard is H.264. H.264 / MPEG-4AVC.

FIG. 1 is a block diagram of an encoding apparatus that encodes these audio data or moving image data at a low bit rate. The conversion unit 120 converts an input signal, which is various data, or a converted input obtained by performing some processing on the input signal from the space-time domain to the frequency domain, and outputs a converted output with reduced correlation. The quantization unit 130 quantizes the conversion output output from the conversion unit 120 and outputs a quantization coefficient with a small total data amount. The entropy encoding unit 190 encodes the quantization coefficient output from the quantization unit 130 using an entropy encoding algorithm, and outputs an encoded signal.

The conversion process in the conversion unit 120 will be described in detail. As shown in (Expression 1), a vector of N points (N-dimensional signal) input to the conversion unit 120 is a conversion input vector ^xn, and an output of a certain conversion T is a conversion output vector (Transform Output) vector. ^Let y be ⁿ .

If the transformation T is a linear transformation, the transformation T can be expressed by a matrix product of a transformation coefficient A that is an N × N matrix and a transformation input vector ^xn , as shown in (Equation 2). Therefore, the element y _i of the transform output vector y ⁿ is expressed as shown in (Equation 3) using the transform coefficient a _ik that is each element of the transform coefficient A.

The conversion coefficient A is designed to reduce the correlation of input signals and concentrate low-dimensional energy. In designing the conversion coefficient A, a conversion coefficient derivation method or conversion method called KLT (Karhunen Loeve transform) is known. KLT is a method for deriving an optimum transform coefficient based on the statistical properties of an input signal, or a transform method using the derived optimum transform coefficient (refer to Non-Patent Document 1 for details). KLT is known to eliminate the correlation of input signals completely and to concentrate energy to a low frequency most efficiently.

However, the conventional encoding method and decoding method using KLT has a problem that the amount of calculation increases.

Specifically, the conversion to the frequency domain optimized based on statistical properties in the conventional image encoding device and image decoding device requires multiplication, and the operation for multiplication There is a problem that the amount is large. That is, the conversion using the conversion coefficient calculated based on the statistical properties of the input signal has a problem that the amount of calculation is large and the total number of conversion coefficients is large.

Therefore, the present invention has been made in view of such a problem, and an object thereof is to provide a decoding method and an encoding method capable of reducing the amount of calculation.

In order to solve the above problem, a decoding method according to an aspect of the present invention includes an entropy decoding step of performing entropy decoding on an encoded signal to generate a plurality of quantized coefficients, and the plurality of quantum An inverse quantization step of inversely quantizing the quantization coefficient to generate a decoded transformed output signal, and a transform coefficient of the second inverse transform is used for the first partial signal constituting a part of the decoded transformed output signal A second inverse transform step for performing a second inverse transform and generating a first partial signal subjected to the second inverse transform, and a first partial signal subjected to the second inverse transform. And a second partial signal that is a portion that has not been subjected to the second inverse transformation, the first inverse transformation is performed using the transform coefficient of the first inverse transformation in a lump. The inverse transformation step and the internal variable necessary for matrix multiplication of the first inverse transformation. A control step of controlling the shift amount after matrix multiplication of the transform coefficient of the second inverse transform according to the bit length of the decoded transform output signal in units of blocks so that the bit length does not exceed a predetermined value; including.

According to the above configuration, it is possible to reduce the amount of calculation and the total number of transform coefficients (elements) by using the second inverse transform step with a reduced number of dimensions.

The encoding method according to an aspect of the present invention includes a conversion step of performing frequency conversion on an input signal to generate a conversion output signal having coefficient values of a plurality of frequency components, and quantizing the conversion output signal. A quantization step for generating a plurality of quantized coefficients, an entropy encoding step for generating an encoded signal by entropy encoding the plurality of quantized coefficients, and a decoding transform by dequantizing the plurality of quantized coefficients An inverse quantization step for generating an output signal, and a second inverse transform is performed on a first partial signal constituting a part of the decoded transformed output signal using a transform coefficient of the second inverse transform, A second inverse transformation step for generating a first partial signal subjected to the second inverse transformation, a first partial signal subjected to the second inverse transformation, and the second inverse transformation. The second part that was not done A first inverse transform step for performing a first inverse transform on a partial signal using a transform coefficient of the first inverse transform in a lump, and an internal necessary for matrix multiplication of the first inverse transform Control for controlling the shift amount after matrix multiplication of the transform coefficient of the second inverse transform according to the bit length of the decoded transform output signal for each block so that the maximum bit length of the variable does not exceed a predetermined value Steps.

According to the above configuration, it is possible to reduce the amount of calculation and the total number of transform coefficients (elements) in encoding of an input signal using inverse transform.

The present invention can be realized not only as such an encoding method or decoding method, but also as a device for processing according to the method, an integrated circuit, and a program for causing a computer to execute processing according to the method. It can also be realized as a storage medium for storing the program.

The decoding method or the encoding method of the present invention can reduce the amount of calculation of conversion and reduce the total number of transform coefficients.

FIG. 1 is a block diagram of an AV data encoding apparatus. FIG. 2 is a block diagram of the conversion unit of the encoding apparatus according to Embodiment 1 of the present invention. FIG. 3A is a conceptual diagram showing a data flow of the conversion unit in Embodiment 1 of the present invention. FIG. 3B is a conceptual diagram showing another data flow of the conversion unit in Embodiment 1 of the present invention. FIG. 4A is a flowchart of the conversion process in the first embodiment of the present invention. FIG. 4B is a flowchart of another conversion process according to Embodiment 1 of the present invention. FIG. 5 is a block diagram of an AV data decoding apparatus according to Embodiment 2 of the present invention. FIG. 6 is a block diagram of the inverse transform unit of the decoding apparatus according to Embodiment 2 of the present invention. FIG. 7A is a diagram conceptually showing the data flow of the inverse transform unit in Embodiment 2 of the present invention. FIG. 7B is a diagram conceptually illustrating another data flow of the inverse transform unit in Embodiment 2 of the present invention. FIG. 7C is a diagram conceptually showing another data flow of the inverse transform unit in Embodiment 2 of the present invention. FIG. 8A is a flowchart of the inverse conversion process in Embodiment 2 of the present invention. FIG. 8B is a flowchart of another inverse conversion process according to Embodiment 2 of the present invention. FIG. 9 is a block diagram of a decoding apparatus according to Embodiment 3 of the present invention. FIG. 10 is a flowchart showing processing operations of the decoding apparatus according to Embodiment 3 of the present invention. FIG. 11A is a diagram for describing a shift amount determination method according to Embodiment 3 of the present invention. FIG. 11B is a diagram for explaining a shift amount determination method according to Embodiment 3 of the present invention. FIG. 12 is a block diagram of a decoding apparatus according to Embodiment 4 of the present invention. FIG. 13 is a diagram for explaining a shift amount determination method according to Embodiment 4 of the present invention. FIG. 14 is a diagram for explaining another method for determining the shift amount according to the fourth embodiment of the present invention. FIG. 15 is a block diagram of a decoding apparatus according to Embodiment 5 of the present invention. FIG. 16A is a flowchart of the pre-shift down process in the inverse transform process according to Embodiment 5 of the present invention. FIG. 16B is a flowchart of another pre-shift down process in the inverse transform process according to Embodiment 5 of the present invention. FIG. 17 is an overall configuration diagram of a content supply system that implements a content distribution service. FIG. 18 is an overall configuration diagram of a digital broadcasting system. FIG. 19 is a block diagram illustrating a configuration example of a television. FIG. 20 is a block diagram illustrating a configuration example of an information reproducing / recording unit that reads and writes information from and on a recording medium that is an optical disk. FIG. 21 is a diagram illustrating a structure example of a recording medium that is an optical disk. FIG. 22A illustrates an example of a mobile phone. FIG. 22B is a block diagram illustrating a configuration example of a mobile phone. FIG. 23 is a diagram showing a structure of multiplexed data. FIG. 24 is a diagram schematically showing how each stream is multiplexed in the multiplexed data. FIG. 25 is a diagram showing in more detail how the video stream is stored in the PES packet sequence. FIG. 26 is a diagram illustrating the structure of TS packets and source packets in multiplexed data. FIG. 27 is a diagram illustrating a data structure of the PMT. FIG. 28 is a diagram illustrating an internal configuration of multiplexed data information. FIG. 29 shows the internal structure of stream attribute information. FIG. 30 shows steps for identifying video data. FIG. 31 is a block diagram illustrating a configuration example of an integrated circuit that realizes the moving picture coding method and the moving picture decoding method according to each embodiment. FIG. 32 is a diagram showing a configuration for switching the drive frequency. FIG. 33 is a diagram showing steps for identifying video data and switching between driving frequencies. FIG. 34 is a diagram showing an example of a look-up table in which video data standards are associated with drive frequencies. FIG. 35 is a diagram illustrating an example of a configuration for sharing a module of the signal processing unit. FIG. 36 is a diagram illustrating another example of a configuration for sharing a module of a signal processing unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. The numerical values, shapes, materials, constituent elements, arrangement positions and connecting forms of the constituent elements, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. The present invention is limited only by the claims. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are not necessarily required to achieve the object of the present invention. It will be described as constituting a preferred form.

(Embodiment 1)
FIG. 2 is a diagram illustrating a configuration of a conversion unit in the encoding apparatus according to the present embodiment. The conversion unit of the present invention performs a second conversion on the first conversion output and the first conversion unit 200 that generates the first conversion output by performing the first conversion on the conversion input (input signal). A second conversion target determining unit 210 that divides the target part (first part) and a non-target part (second part) into two parts, and performs the second conversion on the first part Accordingly, the second conversion unit 220 that generates the second conversion output and the integration unit 230 that generates the conversion output by integrating the second conversion output and the second part are included. The integration unit 230 is conceptually described in the sense that the signals that have been conceptually divided are not in a divided state but in the original dimension, and is a special case of integration in actual information processing. There is no need to perform an action. The same applies to the following embodiments.

Signals such as audio, still images, or moving images are input to the encoding device. The signal to be encoded (Original Signal) that is this signal, or a prediction error signal that is a difference between this signal and a prediction signal that is created based on the previously input encoding target signal is used as the conversion input. Input to the conversion unit 200. In general, a prediction error signal is often input as a conversion target, but prediction is not performed when prediction is not performed assuming that an error is mixed in the transmission path or when energy is small. In addition, an encoding target signal is input as a conversion target. Such a conversion input (Transform Input) is represented by a vector ^xn as shown in (Expression 4).

FIG. 3A is a diagram conceptually illustrating a data flow of the conversion unit in the encoding device of the present embodiment. First, in the first conversion unit 200, is reduced correlation of the transform input x ^n, it converts the input x ⁿ is transformed into a first conversion output y ₁ ^n, which concentrates the energy in the low frequency band. The first conversion output y ₁ ⁿ is divided into a first part (first partial signal) and a second part (second partial signal) by the second conversion target determining unit 210. The division into the first part and the second part is performed so that the correlation energy of the first part is larger than the correlation energy of the second part based on the division integration information. The division integration information is information that causes the second conversion target determination unit 210 to perform control to divide the low frequency band as the first part and the high frequency band as the second part. In addition, the division integration information may be information instructing dynamic control according to input. For example, the division integration information may be information instructing to distribute a component having a large energy to a first portion and to distribute a component having a small energy to a second portion.

The first part (each element included in the first part) generated as described above is rearranged in one dimension by the second conversion target determining unit 210. Further, the second conversion unit 220 reduces the correlation of the first portion, and the first portion is converted into a _second conversion output y ₂ ⁿ in which energy is concentrated in a lower frequency band. In the integration unit 230, the second conversion output y ₂ ⁿ (each element included in the second conversion output) is rearranged in the dimension before being rearranged by the second conversion target determination unit 210, and the second part Integrated with.

In FIG. 3A, the second conversion target is illustrated as an arbitrary area, but is not limited thereto, and may be a rectangular area. In addition, since the second conversion is a non-separable type, the second conversion target determining unit 210 performs the rearrangement to one dimension.

FIG. 3B is a conceptual diagram showing another data flow of the conversion unit in the present embodiment.

As shown in FIG. 3B, when the second conversion has a separation type configuration, the second conversion target determining unit 210 does not perform the rearrangement to one dimension.

FIG. 4A is a flowchart of conversion processing by the conversion unit of the present embodiment. First, in the first conversion unit 200, a first conversion coefficient is determined based on the conversion input ^xn (step S101). Next, the first conversion unit 200 performs the first conversion using the determined first conversion coefficient (step S102). Next, division integration information is determined (step S103). If this division integration information controls the second conversion target determination unit 210 to perform predetermined division, this division integration information is read from the memory or the like of the encoding device. In addition, if the division integration information controls the second conversion target determination unit 210 to perform division according to the first conversion output, the distribution of energy states is considered based on the first conversion output. Thus, the division integration information is derived. Based on the division integration information determined in this way, the first conversion output is divided in the second conversion target determination unit 210 (step S108), and in the second conversion unit 220, based on the first part. Thus, the second conversion coefficient is determined (step S105). Next, the second conversion unit 220 performs second conversion using the determined second conversion coefficient (step S106). In the integration unit 230, the second conversion output and the second part are integrated and output as a conversion output (step S107). Further, the entire operation of steps S101 to S107 in FIG. 4A is defined as step S100.

Note that a predetermined conversion coefficient and division integration information may be used, and the operation in that case is as shown in FIG. 4B.

FIG. 4B is a flowchart of another conversion process by the conversion unit of the present embodiment.

The conversion unit performs the first conversion in the first conversion unit 200 (step S102), determines the second conversion target from the first conversion output (step S105), and sets the determined second conversion target. On the other hand, the second conversion is performed (step S106), and a second conversion output is generated. Further, the conversion unit integrates the second conversion output and the portion of the first conversion output to which the second conversion is not applied (step S107), thereby converting the conversion output of the conversion processing of the present invention. Generate.

Although the second conversion target determining unit 210 and the integrating unit 230 perform the rearrangement of the dimensions of the first part and the second conversion output, the respective rearrangements are performed by the second conversion unit 220. You may go on. Further, when the encoding target is a one-dimensional signal such as audio data, the rearrangement process is not necessary. Further, in the separation-type processing of each dimension that can be regarded as one-dimensional signal processing, the conversion input ^xn input to the conversion unit is a one-dimensional signal, so that the rearrangement processing is not necessary. Note that the second conversion unit 220 may substantially substitute the processing of the second conversion target determination unit 210 and the integration unit 230 by setting the coefficient to zero. The same applies to the following embodiments.

(Embodiment 2)
FIG. 5 is a block diagram of an AV data decoding apparatus according to the present embodiment. This decoding apparatus includes an entropy decoding unit 240, an inverse quantization unit 140, and an inverse conversion unit 150, and decodes an encoded signal obtained by encoding audio data or moving image data at a low bit rate. The decoding process is substantially the reverse process of the encoding process described with reference to FIG. 1 in which entropy decoding is performed on the encoded signal, inverse quantization is performed, and inverse transform is performed. Hereinafter, the inverse transform unit 150 in the present embodiment will be described in detail.

FIG. 6 is a block diagram showing a configuration of the inverse transform unit 150 of the decoding device according to the present embodiment. The inverse transform unit 150 according to the present embodiment has two decoded transform outputs that are a part to be subjected to the second inverse transform (decoded second converted output) and a part that is not the target (decoded second part). A second inverse transformation target determination unit 215 that divides the data into two parts, a second inverse transformation unit 260 that generates a decoded first part by performing a second inverse transformation on the decoded second transformation output, and a decoding An integration unit 235 that generates a decoded first converted output by integrating the first part and the decoded second part, and a decoding conversion input by performing a first inverse conversion on the decoded first converted output. And a first inverse conversion unit 250 to be generated. The integration unit 235 is conceptually described in the sense that the signals generated by conceptually dividing the signals are not in a divided state but in the original dimension, and in actual information processing. It is not necessary to perform a special operation of integration. The same applies to the following embodiments.

An encoded signal obtained by encoding a signal such as a voice, a still image, or a moving image is input to the decoding device. The encoded signal is entropy-decoded and the inversely quantized signal is input to the second inverse transform target determining unit 215 as a decoded transform output y ^.

7A, 7B, and 7C are diagrams conceptually showing the data flow of inverse transform section 150 in the decoding apparatus of the present embodiment. The entropy decoding unit 240 generates a plurality of decoded quantized coefficients by decoding the encoded signal, and the inverse quantizing unit 140 inversely quantizes the plurality of decoded quantized coefficients to obtain the decoded transform output y ^. Generate. The decoded conversion output y ^ is divided into two regions by the second inverse conversion target determination unit 215. The second inverse transform unit 260 performs the second inverse transform on the decoded second transform output y ^ ₂ in one of the two regions, and the decrypted first part becomes Generated. The decoded second part y ^ _{2H in the} other region is not converted, and is integrated with the decoded first part by the integrating unit 235. As a result, a decoded first conversion output ＾ ₁ is generated, and the first reverse conversion unit 250 performs the first reverse conversion on the decoded first conversion output ＾ ₁ . As shown in FIGS. 7B and 7C, when the second inverse transformation takes a separation type configuration, the second inverse transformation target determining unit 215 and the integrating unit 235 do not perform the one-dimensional rearrangement. May be.

FIG. 8A is a flowchart of the inverse conversion process by the inverse conversion unit 150 of the present embodiment. First, division integration information is acquired (step S201). The second inverse transformation target determination unit 215 divides the decoding transformation output y ^ described above into a decoding second transformation output including a low frequency band and a decoding second portion including a high frequency band ( Step S208). The division into the decoded second converted output and the decoded second part is performed based on the division integration information so that the correlation energy of the decoded second converted output is larger than the correlation energy of the decoded second part. Is called. The division integration information is the same as that described in the first embodiment, and the acquisition of the division integration information may be to read out information stored in a predetermined memory or the like, depending on the decoding conversion output. It may be determined dynamically.

The decoded second conversion output (each element included in the decoded second conversion output) generated as described above is rearranged one-dimensionally by the second inverse conversion target determination unit 215, and the second inverse output Input to the converter 260. The transform coefficient of the inverse transform performed by the second inverse transform unit 260 is the inverse matrix of the transform coefficient of the second transform described in the first embodiment or a matrix approximated thereto. The transform coefficient of the inverse matrix is obtained based on the set _SD including the decoded second transform output using, for example, KLT as in the first embodiment (step S203). The second inverse transform unit 260 performs the second inverse transform on the decoded second transform output using the transform coefficient thus obtained, and outputs the decrypted first part (step S204). ). The integration unit 235 rearranges the decoded first part (each element included in the decoded first part) into the dimension before being rearranged by the second inverse transformation target determination unit 215, and outputs the decoded second partial signal. Are integrated with each other to generate a decoded first conversion output y ₁ and output it to the first inverse conversion unit 250 (step S205).

The transform coefficient of the inverse transform performed by the first inverse transform unit 250 is the inverse matrix of the first transform described in the first embodiment or a matrix approximated thereto. The transform coefficient of the inverse matrix is obtained based on the set S _E including the decoded first transform output ＾ ₁ using, for example, KLT as in the first embodiment (step S206). The first inverse transform unit 250 performs the first inverse transform on the decrypted first transform output y ^ ₁ using the transform coefficient thus obtained, and outputs the decoded transform input x ^. (Step S207). Further, the entire operation from step S201 to step S207 in FIG. 8A is defined as step S200.

FIG. 8B is a flowchart of another inverse conversion process by the inverse conversion unit 150 of the present embodiment.

When using a predetermined inverse transform coefficient and division integration information, as shown in FIG. 8B, it is not necessary to explicitly perform the derivation process.

Note that the set S _D and the set S _E are in the relationship between the set S _C and the set S _{A in} the first embodiment, and the set S _D is a smaller set with a smaller number of samples than the set S _E. As described above, the decoding apparatus provided with the inverse transform unit 150 according to the present embodiment can achieve both high-efficiency conversion and reduction in the calculation amount and the data amount as in the first embodiment. .

Note that the second inverse transformation target determination unit 215 and the integration unit 235 perform the rearrangement of the respective dimensions of the decoded second conversion output and the decoded first part. The inverse conversion unit 260 may perform this. That is, a separation type conversion may be used, or a conversion including a zero coefficient may be used. When the decoding target is a one-dimensional signal such as audio data, the rearrangement process is not necessary. Further, since a signal of each dimension when a multi-dimensional signal is configured as a separation type can be regarded as a one-dimensional signal, the decoded transform output y ^ input to the inverse transform unit 150 is a one-dimensional signal, and the above-described dimension arrangement is performed. The process of replacement (rearrangement to one dimension in the second inverse conversion target determination unit 215 and rearrangement to the original dimension in the integration unit 235) is not necessary.

In this embodiment, the decoded conversion output, the decoded conversion input, the decoded signal, and the prediction signal are P-dimensional signals (P is an integer of 2 or more). That is, the decoded conversion output, the decoded second part, the decoded first converted output, and the decoded converted input are P-dimensional signals. The second inverse transform unit 260 may input / output P-dimensional signals or input / output one-dimensional signals.

The second inverse transform target determining unit 215 divides the P-dimensional signal (decoded transform output) into a decoded second converted output and a decoded second part according to the division integration information, and then further outputs a decoded second converted output ( Each element included in the decoded second conversion output is rearranged in one dimension. Rearrangement order information is additionally stored in the division integration information. The integration unit 235 integrates the decoded first part and the decoded second part according to the division integration information, and generates a decoded first conversion output. At this time, the integration unit 235 rearranges the decoded first part (each element included in the decoded first part), which is a one-dimensional signal, into the P dimension based on the rearrangement information stored in the divided integration information. After that, integrate.

Note that, as shown in FIG. 7B, the second inverse transform unit 260 may input and output P-dimensional signals and do not rearrange them into one-dimensional signals. In this case, as shown in FIG. 7C, the second inverse conversion unit 260 may be a separation type (two-stage conversion in the horizontal axis direction and the vertical axis direction). That is, the second inverse transformation unit 260 performs the inverse transformation (first coordinate axis transformation of the second inverse transformation) in the horizontal direction in units of rows, and the inverse transformation in the vertical direction (second coordinate of the second inverse transformation). Coordinate axis conversion). The order of horizontal and vertical may be reversed. A row- or column-by-column conversion with one element is equivalent to not performing the actual processing, so the conversion may be skipped, or the norm correction processing in the subsequent stage may be replaced with the conversion. You may go to The transform coefficient of the inverse transform of the row transform and the transform coefficient of the inverse transform of the column transform may be the same or different. By using the same conversion coefficient for all rows, the data amount of the conversion coefficient may be reduced, or by using different conversion coefficients for each row, the row conversion is performed due to the difference in statistical properties for each row. May be applied to improve the conversion performance. The column conversion is similar to the row conversion, and the same conversion coefficient may be used for all the columns, or different conversion coefficients may be used.

(Embodiment 3)
The decoding apparatus according to the present embodiment performs a shift described later that performs processing after the second inverse transform for each block according to the bit length of the input signal of the second inverse transform or the bit length of the output signal. And a shift unit (to be described later) that performs processing after the first inverse transformation adaptively downshifts or upshifts the signal (bit length), and the circuit resources necessary for the first inverse transformation are constant. The following is to be suppressed.

FIG. 9 is a block diagram of the decoding apparatus according to the present embodiment. Signals and components having the same meaning as in FIGS. 5 and 6 are given the same reference numerals, and description of the same parts of operation is omitted. FIG. 10 is a flowchart showing the processing operation of the decoding apparatus according to the present embodiment.

The entropy decoding unit 240 performs entropy decoding on the encoded signal to generate a plurality of quantized coefficients (step S208). The inverse quantization unit 140 inversely quantizes the plurality of quantized coefficients and outputs a decoded transform output (decoded transform output signal) (step S209). The second inverse transformation target determination unit 215 uses the decoded second transformation output (first partial signal) as a part for performing the second inverse transformation and the decoded second as a part for which the second inverse transformation target determination unit 215 does not perform the decoding transformation output. (Second partial signal). The bit length control unit 301 detects the bit length of the decoded second conversion output for each input block, and shifts SA for each of the second inverse transform shift unit 303 and the first inverse transform shift unit 305. And SB are output (step S210). The second inverse transform shift unit 303 and the first inverse transform shift unit 305 are the above-described shift units.

The second inverse transformation unit 260 in FIG. 6 shifts down the multiplication result (bit length) by a predetermined amount, with the second inverse transformation matrix multiplication unit 302 that performs multiplication of the matrix of transformation coefficients shown in FIG. This corresponds to the second inverse transform shift unit 303. Expressing the inverse transformation process as a matrix multiplication followed by a shift-down is conceptual, and the multiplication and shift-down processes are performed sequentially for frequency position units, frequency position rows and columns, etc. You may go. Alternatively, the downshifting may be performed in a plurality of downshifts instead of at once. For example, when performing 2N-bit shift-down, the 2N-bit shift-down may be performed twice, such as N-bit shift-down and N-bit shift-down.

The second inverse transformation matrix multiplication unit 302 performs matrix multiplication on the decoded second transformation output with a matrix of transformation coefficients of the second inverse transformation to generate a second inverse transformation multiplication output. It is assumed that the maximum effective bit length that can be processed by the second inverse transformation matrix multiplication unit 302 is MK, and the bit length increased by the matrix operation is K. The second inverse transform shift unit 303 shifts down or up according to the shift amount SA of the second inverse transform multiplication output, and outputs the decoded first part (step S204). The integration unit 235 integrates the decoded second part and the decoded first part, and outputs a decoded first conversion output. The first inverse transformation matrix multiplication unit 304 and the first inverse transformation shift unit 305 correspond to the first inverse transformation unit 250 shown in FIG. 6 and perform a transform coefficient multiplication process and a subsequent downshift process. These processes are similar to the above-described second inverse transformation and are conceptual. The first inverse transformation matrix multiplication unit 304 performs matrix multiplication on the decoded first transformation output with a matrix of transformation coefficients of the first inverse transformation, and outputs a first inverse transformation multiplication output (step S207). The first inverse transform shift unit 305 shifts down or up the first transform multiplication output according to the shift amount SB, and outputs a decoded transform input.

FIG. 11A and FIG. 11B are diagrams for explaining a method of determining the shift amounts SA and SB. First, an example of the bit length when the shift amount SA is 0, that is, when neither downshifting nor upshifting is performed in the second inverse transform shift unit 303 will be described with reference to FIG. 11A. Note that FIG. 11A describes information on the bit length of each processing unit from left to right in correspondence with the flow of processing during decoding. It is assumed that the bit length of the output signal of each processing unit matches the bit length of the variable inside the processing unit.

Suppose that the decoding conversion output of the inverse quantization unit 140 is A bits. If the second inverse transform matrix multiplication unit 302 increases the bit length by K bits by multiplication, the second inverse transform multiplication output becomes A + K bits. Next, since the second inverse transform shift unit 303 outputs the input signal without shifting up or down in this example, the bit length of the second inverse transform multiplication output that is the first decoded portion is A + K bits. Remains. If the first inverse transformation matrix multiplication unit 304 increases D bits by multiplication, the bit length of the first inverse transformation multiplication output (and the internal variable of the first inverse transformation matrix multiplication unit 304) that is the output is A + K + D. .

Here, assuming that the maximum bit length that can be processed by first inverse transformation matrix multiplication section 304 is MD, the decoding apparatus according to the present embodiment determines shift amount SA and shift amount SB so that A + K + D is equal to or less than MD. To do. That is, the shift amount SA of the second inverse transform shift unit 303 is determined by the bit length control unit 301 as SA = MD− (A + K + D). For example, when K = 8, D = 10, MD = 24, if the bit length A of the decoding conversion output of the block is 12 bits, the shift amount SA = 24− (12 + 8 + 10) = − 6, and the second inverse conversion shift The unit 303 performs 6-bit shift down. If the bit length A of the decoding conversion output of the block is 2 bits, the shift amount SA = 24− (2 + 8 + 10) = 4, and the second inverse conversion shift unit 303 performs 4-bit shift-up. When the shift amount SA is zero, the second inverse transform shift unit 303 does not shift up or down.

The bit length when this determination method is used will be described with reference to FIG. 11B. When the second inverse transform shift unit 303 shifts up or down MD− (A + K + D), the bit length of the output is A + K + (MD− (A + K + D)) = MD−D. Since the first inverse transformation matrix multiplication unit 304 increases D bits by multiplication, the bit length of the output is MD−D + D = MD. This bit length matches (that is, does not exceed) the MD that is the maximum bit length of the first inverse transformation matrix multiplication unit 304.

By this method, the bit length control unit 301 controls the shift amount SA of the second inverse transform shift unit 303 according to the bit length of each block, so that the first inverse transform matrix multiplication unit 304 has a bit length to be supported. A certain MD can be kept low, and the circuit scale can be reduced. In addition to the effect of reducing the circuit scale, when the shift amount SA is positive, the bit length of the input signal to the first inverse transformation matrix multiplication unit 304 increases, so the first inverse transformation matrix multiplication unit 304 and The effect of the calculation error that may occur in the first inverse transformation shift unit 305 is reduced, and the effect of increasing the accuracy of the first inverse transformation (inverse transformation with respect to the decoded first transformation output) is also obtained. If the effect of increasing the calculation accuracy is not required, the second inverse transform shift unit 303 may set the shift amount SA to 0 when the bit length control unit 301 determines the positive shift amount SA. Further, for example, the target maximum bit length is given to the bit of the decoding conversion input due to the relationship with the process (prediction process or filter process) following the inverse conversion. Assuming that it is E bits, the bit length control unit 301 determines the shift amount SB of the first inverse transform shift unit 305 as E-MD. Similar to the second inverse transform shift unit 303, the first inverse transform shift unit 305 shifts up if the E-MD is a positive number and shifts down if the E-MD is a negative number.

In addition, for the decoded second portion that does not pass through the second inverse transformation matrix multiplication unit 302, the second partial shift is performed so that the bit accuracy of the decoded second portion matches the bit accuracy of the decoded first portion. The unit 306 shifts the decoded second part, and outputs the shifted decoded second part to the integrating unit 235. The bit length control unit 301 determines and outputs the shift amount SA2 of the second partial shift unit 306. The shift amount SA2 is determined by subtracting the increased bit amount K of the second inverse transform matrix multiplication unit 302 from the shift amount SA, that is, SA2 = SA−K = MD− (A + D).

Note that the bit length control unit 301 and the second inverse conversion target determination unit 215 may interchange the processing order. The bit length of the second conversion target coefficient may be controlled as described so far, or all the coefficients may be replaced regardless of whether it is the second conversion target. The bit length may be controlled.

Note that the bit length control unit 301 calculates the bit length for each coefficient (element) of the input decoded transform output, and sets the maximum value as the bit length of the block. Since the decoded transform output is before inverse transform, it includes many zero coefficients. These zero coefficients may be excluded from the target of the bit length calculation to reduce the calculation amount of the bit length calculation. As described above, the bit length control unit 301 detects the bit length of the decoding conversion output of the block.

(Embodiment 4)
FIG. 12 is a block diagram of the decoding apparatus according to the present embodiment.

As shown in FIG. 12, the decoding apparatus according to the present embodiment performs the second inverse transform (processing by the second inverse transform matrix multiplier 302 and the second inverse transform shift unit 303) and the first inverse transform (first Norm correction is performed between the 1 inverse transformation matrix multiplication unit 304 and the first inverse transformation shift unit 305). The norm correction is a process for correcting a mismatch in the size (norm) of the conversion base that occurs when the multiplication process is reduced by using shift and addition in the conversion coefficient of the first inverse transform. This process is realized by a norm correction multiplication unit 310 that performs multiplication processing for each frequency position, and a norm correction shift unit 311 that performs subsequent shift processing. Similar to the above-described relationship between inverse multiplication and shift, this order relationship is conceptual, and multiplication and shift may be performed with a small granularity such as a frequency position. In this configuration, the bit length control unit 301 determines the shift amount SA so that the bit length required for norm correction does not exceed the maximum bit length of the norm correction multiplication unit 310, and the shift amount of the norm correction shift unit 311. Determine the SC.

FIG. 13 is a diagram for explaining a shift amount calculation method (determination method) in the present embodiment. It is assumed that the maximum bit length that can be processed by the norm correction multiplication unit 310 is MN, and the increased bit length by the multiplication processing is N. The bit length of the output of the second inverse transform matrix multiplier 302 is A + K, and the norm correction multiplier 310 increases N bits. Therefore, in order to prevent A + K + N from exceeding the maximum bit length MN of the norm correction multiplication unit 310, the bit length control unit 301 determines the shift amount SA = + MN− (A + K + N) of the second inverse transform shift unit 303. . Thereby, the bit length of the output (and internal processing) of the norm correction multiplication unit 310 is MN. The norm correction shift unit 311 performs a shift so that the number of bits necessary for the first inverse transformation on the output does not exceed the maximum bit length MD of the first inverse transformation matrix multiplication unit 304. That is, D bits are increased by multiplication of the first inverse transformation by the first inverse transformation matrix multiplication unit 304 and the current bit length is MN. Therefore, the bit length control unit 301 includes the shift amount SC of the norm correction shift unit 311. Is determined to be MD− (D + MN). The output shifted by the shift amount SC by the norm correction shift unit 311 is MD-D bits, and is input to the first inverse transformation matrix multiplication unit 304, and is increased by D bits to become MD bits. Therefore, it is possible to prevent the output from exceeding the maximum bit length MD of the circuit of the first inverse transformation matrix multiplication unit 304. The subsequent processing is the same as in the third embodiment.

FIG. 14 is a diagram for explaining another calculation method (determination method) of the shift amount in the present embodiment. The bit length of the input signal (decoded second conversion output) to the second inverse transformation matrix multiplication unit 302 may be controlled in advance. That is, as shown in FIG. 14, the A bit may be shifted by + MK− (K + A). Thereby, the number of bits necessary for the second inverse transformation can be suppressed to be equal to or less than the maximum bit length MK of the second inverse transformation matrix multiplication unit 302. Subsequent processing is equivalent to the above-described processing, and thus description thereof is omitted. Note that such a calculation method, that is, a method of controlling the bit length in advance for the decoded second conversion output may be applied to the third embodiment.

Further, the decoding methods in

Embodiments

3 and 4 are also used when the quantization coefficient is inversely quantized and inversely transformed in an encoding device that encodes an input signal. That is, the encoding device performs a frequency conversion on an input signal, generates a conversion output signal having coefficient values of a plurality of frequency components, and quantizes the conversion output signal to generate a plurality of quantization coefficients. An entropy encoding step for entropy encoding the plurality of quantized coefficients to generate an encoded signal, and an inverse for dequantizing the plurality of quantized coefficients to generate a decoded transform output signal. A second inverse transform using a transform coefficient of a second inverse transform on the first partial signal that constitutes a part of the decoded transform output signal; and the second inverse transform In the second inverse transform step for generating the first partial signal, the first partial signal subjected to the second inverse transform, and the portion not subjected to the second inverse transform Pair with some second partial signal The first inverse transform step for performing the first inverse transform using the transform coefficient of the first inverse transform collectively and the maximum bit length of the internal variable required for the matrix multiplication of the first inverse transform And a control step for controlling the shift amount after matrix multiplication of the transform coefficient of the second inverse transform in accordance with the bit length of the decoded transform output signal so as not to exceed a predetermined value. To do. Note that the result of the inverse transformation process including the inverse quantization step, the second inverse transformation step, the first inverse transformation step, and the control step is an input signal (for example, a prediction error signal) to be transformed in the transformation step. ).

(Embodiment 5)
The amount of information (information accuracy) is lost for each shift-down process. That is, if a downshift is performed each time in individual processes such as prediction, inverse quantization, and inverse transformation, the amount of information (information accuracy) disappears each time. Therefore, there is a method of ensuring bit accuracy rather frequently and concentrating the downshift processing for each time as much as possible only at the final stage to suppress the loss of information amount (information accuracy). This is sometimes called an internal bit extension technique (IBDI: Internal Bit Depth Increase). This IBDI method is the opposite of the design philosophy of trying to suppress the maximum bit length of the inverse conversion circuit as much as possible. If the IBDI method is applied, the following processing is performed to control the required bit length so as not to exceed the maximum value of the circuit scale. The IBDI bit extension may be inserted in an arbitrary processing step. Here, it is assumed that the output value of the inverse quantization unit 140 is extended by a predetermined bit.

FIG. 15 is a block diagram of the decoding apparatus according to the present embodiment. The decoding device in the present embodiment includes a second inverse transform preshift unit 321 and a second inverse transform control unit 320. The second inverse transform control unit 320 operates the control signal CtrlA for instructing the operation of the second inverse transform matrix multiplication unit 302 based on a flag signal that is linked with the in-plane prediction mode or is multiplexed separately in the stream. decide. The instruction indicated by the control signal CtrlA includes an instruction hx for performing only horizontal reverse conversion, an instruction xv for performing only vertical reverse conversion, an instruction hv for performing both horizontal reverse conversion and vertical reverse conversion, and both horizontal reverse conversion and vertical reverse conversion. There may be four types of instructions xx that do not perform. The bit increase due to the second inverse transformation is maximized in the case of the instruction hv. Therefore, only in this case, the second inverse transform preshift unit 321 receives the input signal of the second inverse transform matrix multiplication unit 302 (that is, the decoded second signal) so that the required bit length does not exceed the maximum length of the circuit. The conversion output) is shifted down by a predetermined value in advance (no special processing is required for the second decoding portion).

Specifically, when the bit length of IBDI is 4 bits and the transformation matrix of the second inverse transformation by the second inverse transformation matrix multiplication unit 302 is 7 bits, the second inverse transformation preshift unit 321 Only when it is shifted down by 3 bits in advance. In the case of the instructions hx, xv, and xx, the second inverse transform preshift unit 321 does not perform this downshift. When N bits of pre-shift down are performed, the shift down amount of the second inverse transform shift unit 303 following the second inverse transform is reduced by N. As described above, when the decoded second conversion output is input to the second inverse transformation matrix multiplication unit 302, the bit length required for the second inverse transformation is changed to the second inverse transformation by IBDI by performing the downshift. Control can be performed so as not to exceed the maximum value of the circuit of the matrix multiplication unit 302, and further, downshifting is limited to the case of the instruction hv in which the increase in bit length is maximum (when both horizontal reverse conversion and vertical reverse conversion are performed) By applying, loss of information amount due to shift down application can be minimized. The

above bit lengths

4, 7, and 3 are examples, and the present invention is not limited to these.

FIG. 16A is a flowchart showing processing operations of the second inverse transform control unit 320 and the second inverse transform preshift unit 321. The second inverse transform control unit 320 determines the presence / absence of each of the horizontal inverse transform (H) and the vertical inverse transform (V) in conjunction with the in-plane prediction mode. Alternatively, it is determined based on flag information in the encoded stream. Or it determines using these combinations etc. (step S220). The second inverse transform pre-shift unit 321 determines whether to perform both vertical inverse transform and horizontal inverse transform based on the control signal CtrlA indicating the determined content (step S221). When performing, the 2nd inverse transformation preshift part 321 performs the preshift down of predetermined bit length (step S222). If not, the second inverse transform preshift unit 321 does not perform preshift down (step S223).

FIG. 16B is a flowchart showing another processing operation of the second inverse transform control unit 320 and the second inverse transform preshift unit 321. The second inverse transform preshift unit 321 determines the presence or absence of each of the horizontal inverse transform and the vertical inverse transform based on the control signal CtrlA indicating the content determined in step S220 (step S221), and the horizontal inverse transform and the vertical inverse When it is determined that both conversions are present (H = V = 1), pre-shift down is performed (step S224). When it is determined in step S221 that both are not present but only one is present (H = 1, V = 0 || H = 0, V = 1), the second inverse transform preshift unit 321 Performs a pre-shift down by a small amount compared to step S224 (step S225). If it is determined in step S221 that neither is present, the second inverse transform preshift unit 321 does not perform preshift down (step S226).

By controlling in this way, even when IBDI is applied, appropriate second inverse transformation can be performed within the maximum bit range of the circuit of the second inverse transformation matrix multiplication unit 302, and adaptive By the control, it is possible to minimize a decrease in calculation accuracy due to the preshift down.

(Embodiment 6)
By recording a program for realizing the configuration of the moving image encoding method (encoding method) or the moving image decoding method (decoding method) described in each of the above embodiments on a storage medium, The processing shown in the form can be easily performed in an independent computer system. The storage medium may be any medium that can record a program, such as a magnetic disk, an optical disk, a magneto-optical disk, an IC card, and a semiconductor memory.

Furthermore, application examples of the moving picture encoding method (encoding method) and moving picture decoding method (decoding method) shown in the above embodiments and a system using the same will be described. The system has an image encoding / decoding device including an image encoding device using an image encoding method and an image decoding device using an image decoding method. Other configurations in the system can be appropriately changed according to circumstances.

FIG. 17 is a diagram showing an 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, a game machine ex115 via the Internet ex101, the Internet service provider ex102, the telephone network ex104, and the base stations ex106 to ex110. Etc. are connected.

However, the content supply system ex100 is not limited to the configuration shown in FIG. 17, and may be connected by combining any one of the elements. In addition, each device may be directly connected to the telephone network ex104 without going from the base station ex106, which is a fixed wireless station, to ex110. In addition, the devices may be directly connected to each other via short-range wireless or the like.

The camera ex113 is a device that can shoot moving images such as a digital video camera, and the camera ex116 is a device that can shoot still images and movies such as a digital camera. The mobile phone ex114 is 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). It is possible to use any of the above-mentioned systems, 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, thereby enabling live distribution and the like. In live distribution, the content (for example, music live video) captured by the user using the camera ex113 is encoded as described in the above embodiments (that is, the encoding device of the present invention). ) To the streaming server ex103. On the other hand, the streaming server ex103 stream-distributes the content data transmitted to the requested client. Examples of the client include a computer ex111, a PDA ex112, a camera ex113, a mobile phone ex114, and a game machine ex115 that can decode the encoded data. Each device that receives the distributed data decodes the received data and reproduces it (that is, functions as the decoding device of the present invention).

Note that the captured data may be encoded by the camera ex113, the streaming server ex103 that performs data transmission processing, or may be shared with each other. Similarly, the decryption processing of the distributed data may be performed by the client, the streaming server ex103, or may be performed in common with each other. In addition 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 performed in a shared manner.

Further, these encoding / decoding processes are generally performed in the computer ex111 and the LSI ex500 included in each device. The LSI ex500 may be configured as a single chip or a plurality of chips. It should be noted that moving image encoding / decoding software is incorporated into some recording medium (CD-ROM, flexible disk, hard disk, etc.) that can be read by the computer ex111, etc., and encoding / decoding processing is performed using the software. May be. Furthermore, when the mobile phone ex114 is equipped with a camera, 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 process, record, and distribute data in a distributed manner.

As described above, in the content supply system ex100, the encoded data can be received and reproduced by the client. Thus, in the content supply system ex100, the information transmitted by the user can be received, decrypted and reproduced by the client in real time, and personal broadcasting can be realized even for a user who does not have special rights or facilities.

In addition to the example of the content supply system ex100, as shown in FIG. 18, the digital broadcast system ex200 also includes at least the video encoding device (encoding device) or the video decoding device according to each of the above embodiments. Any of (decoding device) can be incorporated. Specifically, in the broadcast station ex201, multiplexed data obtained by multiplexing music data and the like on video data is transmitted to a communication or satellite ex202 via radio waves. This video data is data encoded by the moving image encoding method described in the above embodiments (that is, data encoded by the encoding apparatus of the present invention). Receiving this, the broadcasting satellite ex202 transmits a radio wave for broadcasting, and this radio wave is received by a home antenna ex204 capable of receiving satellite broadcasting. The received multiplexed data is decoded and reproduced by an apparatus such as the television (receiver) ex300 or the set top box (STB) ex217 (that is, functions as the decoding apparatus of the present invention).

Also, 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, multiplexes and writes it with a music signal. It is possible to mount the moving picture decoding apparatus or moving picture encoding apparatus described in the above embodiments. 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 using the recording medium ex215 on which the multiplexed data is recorded. Alternatively, a moving picture decoding apparatus may be mounted in a set-top box ex217 connected to a cable ex203 for cable television or an antenna ex204 for satellite / terrestrial broadcasting and 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 illustrating a television (receiver) ex300 that uses the video decoding method and the video encoding method described in each of the above embodiments. The television ex300 obtains or outputs multiplexed data in which audio data is multiplexed with video data via the antenna ex204 or the cable ex203 that receives the broadcast, and demodulates the received multiplexed data. Alternatively, the modulation / demodulation unit ex302 that modulates multiplexed data to be transmitted to the outside, and the demodulated multiplexed data is separated into video data and audio data, or the video data and audio data encoded by the signal processing unit ex306 Is provided with a multiplexing / demultiplexing unit ex303.

Also, the television ex300 decodes each of audio data and video data, or encodes each information, an audio signal processing unit ex304, a video signal processing unit ex305 (functions as an encoding device or a decoding device of the present invention). ), A speaker ex307 for outputting the 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 includes an interface unit ex317 including an operation input unit ex312 that receives an input of a user operation. Furthermore, the television ex300 includes a control unit ex310 that performs overall control of each unit, and a power supply circuit unit ex311 that supplies power to each unit. In addition to the operation input unit ex312, the interface unit ex317 includes a bridge unit ex313 connected to an external device such as a reader / recorder ex218, a recording unit ex216 such as an SD card, and an external recording unit such as a hard disk. A driver ex315 for connecting to a medium, a modem ex316 for connecting to a telephone network, and the like may be included. Note that the recording medium ex216 is capable of electrically recording information by using a nonvolatile / volatile semiconductor memory element to be stored. Each part of the television ex300 is 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 and the like will be described. The television ex300 receives a user operation from the remote controller ex220 or the like, and demultiplexes the multiplexed data demodulated by the modulation / demodulation unit ex302 by the multiplexing / demultiplexing unit ex303 based on the control of the control unit ex310 having a CPU or the like. Furthermore, 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. At the time of output, these signals may be temporarily stored in the buffers ex318, ex319, etc. so that the audio signal and the video signal are reproduced in synchronization. Also, the television ex300 may read multiplexed data from recording media ex215 and ex216 such as a magnetic / optical disk and an SD card, not from broadcasting. Next, a configuration in which the television ex300 encodes an audio signal or a video signal and transmits the signal to the outside or to a recording medium will be described. The television ex300 receives a user operation from the remote controller ex220 and the like, encodes an audio signal with the audio signal processing unit ex304, and converts the video signal with the video signal processing unit ex305 based on the control of the control unit ex310. Encoding is performed using the encoding method described in (1). The encoded audio signal and video signal are multiplexed by the multiplexing / demultiplexing unit ex303 and output to the outside. When multiplexing, these signals may be temporarily stored in the buffers ex320, ex321, etc. so that the audio signal and the video signal 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, in addition to the illustrated example, data may be stored in the buffer as a buffer material that prevents system overflow and underflow, for example, between the modulation / demodulation unit ex302 and the multiplexing / demultiplexing unit ex303.

In addition to acquiring audio data and video data from broadcasts, recording media, and the like, the television ex300 has a configuration for receiving AV input of a microphone and a camera, and performs encoding processing on the data acquired from them. Also good. 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 a configuration.

In addition, when reading or writing multiplexed data from a recording medium by the reader / recorder ex218, the decoding process or the encoding process may be performed by either the television ex300 or the reader / recorder ex218, The reader / recorder ex218 may share with each other.

As an example, FIG. 20 shows a configuration of the information reproducing / recording unit ex400 when data is read from or written to an optical disk. The information reproducing / recording unit ex400 includes elements ex401, ex402, ex403, ex404, ex405, ex406, and ex407 described below. The optical head ex401 irradiates a laser spot on the recording surface of the recording medium ex215 that is an optical disk to write information, and detects reflected light from the recording surface of the recording medium ex215 to read the information. The modulation recording unit ex402 electrically drives a semiconductor laser built in the optical head ex401 and modulates the laser beam according to the recording data. The reproduction demodulator 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 and demodulates the signal component recorded on the recording medium ex215, and is necessary To play back 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 controller ex406 moves the optical head ex401 to a predetermined information track while controlling the rotational drive of the disk motor ex405, and performs a laser spot tracking process. The system control unit ex407 controls the entire information reproduction / recording unit ex400. In the reading and writing processes described above, the system control unit ex407 uses various kinds of information held in the buffer ex404, and generates and adds new information as necessary, and the modulation recording unit ex402, 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 a coordinated manner. The system control unit ex407 is composed of, for example, a microprocessor, and executes these processes by executing a read / write program.

In the above, the optical head ex401 has been described as irradiating a laser spot. However, a configuration in which higher-density recording is performed using near-field light may be used.

FIG. 21 shows a schematic diagram of a recording medium ex215 that is an optical disk. Guide grooves (grooves) are formed in a spiral shape on the recording surface of the recording medium ex215, and address information indicating the absolute position on the disc is recorded in advance on the information track ex230 by changing the shape of the groove. This address information includes information for specifying the position of the recording block ex231 that is a unit for recording data, and the recording block is specified by reproducing the information track ex230 and reading the address information in a recording or reproducing apparatus. Can do. Further, 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 user data is the data recording area ex233, and the inner circumference area ex232 and the outer circumference area ex234 arranged on the inner or outer circumference of the data recording area ex233 are used for specific purposes other than user data recording. Used. The information reproducing / recording unit ex400 reads / writes encoded audio data, video data, or multiplexed data obtained by multiplexing these data with respect to the data recording area ex233 of the recording medium ex215.

In the above description, an optical disk such as a single-layer DVD or BD has been described as an example. However, the present invention is not limited to these, and an optical disk having a multilayer structure and capable of recording other than the surface may be used. Also, an optical disc with a multi-dimensional recording / reproducing structure, such as recording information using light of different wavelengths in the same place on the disc, or recording different layers of information from various angles. It may be.

Also, in the digital broadcasting system ex200, the car ex210 having the antenna ex205 can receive data from the satellite ex202 and the like, and the moving image can be reproduced on a display device such as the car navigation ex211 that the car ex210 has. The configuration of the car navigation ex211 may be, for example, a configuration in which a GPS receiving unit is added in the configuration shown in FIG.

FIG. 22A is a diagram showing the mobile phone ex114 using the moving picture decoding method and the moving picture encoding method described in the above embodiment. The mobile phone ex114 includes an antenna ex350 for transmitting and receiving radio waves to and from the base station ex110, a camera unit ex365 capable of capturing video and still images, a video captured by the camera unit ex365, a video received by the antenna ex350, and the like Is provided with a display unit ex358 such as a liquid crystal display for displaying the decrypted data. The mobile phone ex114 further includes a main body unit having an operation key unit ex366, an audio output unit ex357 such as a speaker for outputting audio, an audio input unit ex356 such as a microphone for inputting audio, a captured video, In the memory unit ex367 for storing encoded data or decoded data such as still images, recorded audio, received video, still images, mails, or the like, or an interface unit with a recording medium for storing data A slot 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 part ex361, an operation input control part ex362, and a video signal processing part ex355 with respect to a main control part ex360 that comprehensively controls each part of the main body including the display part ex358 and the operation key part ex366. , A camera interface unit ex363, an LCD (Liquid Crystal Display) control unit ex359, a modulation / demodulation unit ex352, a multiplexing / demultiplexing unit ex353, an audio signal processing unit ex354, a slot unit ex364, and a memory unit ex367 are connected to each other via a bus ex370. ing.

When the end of call and the power key are turned on by a user operation, the power supply circuit unit ex361 starts up the mobile phone ex114 in an operable state by supplying power from the battery pack to each unit.

The cellular phone ex114 converts the audio signal collected by the audio input unit ex356 in the voice call mode into a digital audio signal by the audio signal processing unit ex354 based on the control of the main control unit ex360 having a CPU, a ROM, a RAM, and the like. Then, this is subjected to spectrum spread processing by the modulation / demodulation unit ex352, digital-analog conversion processing and frequency conversion processing are performed by the transmission / reception unit ex351, and then transmitted via the antenna ex350. The mobile phone ex114 also amplifies the received data received via the antenna ex350 in the voice call mode, performs frequency conversion processing and analog-digital conversion processing, performs spectrum despreading processing by the modulation / demodulation unit ex352, and performs voice signal processing unit After being converted into an analog audio signal by ex354, this is output from the audio output unit ex357.

Further, when an e-mail is transmitted in the data communication mode, the text data of the e-mail input by operating the operation key unit ex366 of the main unit is sent to the main control unit ex360 via the operation input control unit ex362. The main control unit ex360 performs spread spectrum processing on the text data in the modulation / demodulation unit ex352, performs digital analog conversion processing and frequency conversion processing in the transmission / reception unit ex351, and then transmits the text data to the base station ex110 via the antenna ex350. . In the case of receiving an e-mail, almost the reverse process is performed on the received data and output to the display unit ex358.

When transmitting video, still images, 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 encoding method described in the above embodiments. Encode (that is, function as the encoding apparatus of the present invention), and send the encoded video data to the multiplexing / demultiplexing unit ex353. The audio signal processing unit ex354 encodes the audio signal picked up by the audio input unit ex356 while the camera unit ex365 images a video, a still image, etc., and sends the encoded audio data to the multiplexing / separating unit ex353. To do.

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

Decode multiplexed data received via antenna ex350 when receiving video file data linked to a homepage, etc. in data communication mode, or when receiving e-mail with video and / or audio attached Therefore, the multiplexing / separating unit ex353 separates the multiplexed data into a video data bit stream and an audio data bit stream, and performs video signal processing on the video data encoded via the synchronization bus ex370. The encoded audio data is supplied to the audio signal processing unit ex354 while being supplied to the unit ex355. The video signal processing unit ex355 decodes the video signal by decoding using the video decoding method corresponding to the video encoding method shown in each of the above embodiments (that is, functions as the decoding device of the present invention). For example, video and still images included in the moving image file linked to the home page are displayed from the display unit ex358 via the LCD control unit ex359. The audio signal processing unit ex354 decodes the audio signal, and the audio is output from the audio output unit ex357.

In addition to the transmission / reception type terminal having both the encoder and the decoder, the terminal such as the mobile phone ex114 is referred to as a transmission terminal having only an encoder and a receiving terminal having only a decoder. There are three possible mounting formats. Furthermore, in the digital broadcasting system ex200, it has been described that multiplexed data in which music data or the like is multiplexed with video data is received and transmitted, but data in which character data or the like related to video is multiplexed in addition to audio data It may be video data itself instead of multiplexed data.

As described above, the moving picture encoding method or the moving picture decoding method shown in each of the above embodiments can be used in any of the above-described devices / systems. The described effect can be obtained.

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

(Embodiment 7)
The moving picture coding method or apparatus shown in the above embodiments and the moving picture coding method or apparatus compliant with different standards such as MPEG-2, MPEG4-AVC, and VC-1 are appropriately switched as necessary. Thus, it is also possible to generate video data.

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

In order to solve this problem, multiplexed data obtained by multiplexing audio data or the like with video data is configured to include identification information indicating which standard the video data conforms to. A specific configuration of multiplexed data including video data generated by the moving picture encoding method or apparatus shown in 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 a structure of multiplexed data. As shown in FIG. 23, multiplexed data is obtained by multiplexing one or more 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 portion of the movie and the sub-audio mixed with the main audio, and the presentation graphics stream indicates the subtitles of the movie. Here, the main video indicates a normal video displayed on the screen, and the sub-video is a video displayed on a small screen in the main video. The interactive graphics stream indicates an interactive screen created by arranging GUI components on the screen. The video stream is encoded by the moving image encoding method or apparatus shown in the above embodiments, or the moving image encoding method or apparatus conforming to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. 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 for video streams used for movie images, 0x1100 to 0x111F for audio streams, 0x1200 to 0x121F for presentation graphics, 0x1400 to 0x141F for interactive graphics streams, 0x1B00 to 0x1B1F are assigned to video streams used for sub-pictures, and 0x1A00 to 0x1A1F are assigned to audio streams used for sub-audio mixed with the main audio.

FIG. 24 is a diagram schematically showing how multiplexed data is multiplexed. First, a video stream ex235 composed of a plurality of video frames and an audio stream ex238 composed of a plurality of audio frames are converted into PES packet sequences ex236 and ex239, respectively, and converted into TS packets ex237 and ex240. Similarly, the data of the presentation graphics stream ex241 and interactive graphics ex244 are converted into PES packet sequences 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 the video stream. The second level shows a PES packet sequence. As shown by arrows yy1, yy2, yy3, and yy4 in FIG. 25, a plurality of video presentation units in a video stream are divided into pictures, B pictures, and P pictures and stored in the payload of the PES packet. . Each PES packet has a PES header, and a PTS (Presentation Time-Stamp) that is a display time of a picture and a DTS (Decoding Time-Stamp) that is a decoding time of a picture are stored in the PES header.

FIG. 26 shows the format of the TS packet that is 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 a PID for identifying a stream and a 184-byte TS payload for storing data. The PES packet is divided and stored in the TS payload. The In the case of a BD-ROM, a 4-byte TP_Extra_Header is added to a TS packet, forms a 192-byte source packet, and is written in multiplexed data. In TP_Extra_Header, information such as ATS (Arrival_Time_Stamp) is described. 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 head of the multiplexed data is called SPN (source packet number).

In addition, 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 each stream such as video / audio / caption. 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 the PID of each stream such as video / audio / subtitles included in the multiplexed data and the attribute information of the stream corresponding to each PID, and has various descriptors related to the multiplexed data. The descriptor includes copy control information for instructing permission / non-permission of copying of multiplexed data. In order to synchronize the ATC (Arrival Time Clock), which is the ATS time axis, and the STC (System Time Clock), which is the PTS / DTS time axis, the PCR corresponds to the ATS in which the PCR packet is transferred to the decoder. Contains STC time information.

FIG. 27 is a diagram for explaining the data structure of the PMT in detail. A PMT header describing the length of data included in the PMT is arranged at the head of the PMT. After that, a plurality of descriptors related to multiplexed data are arranged. The copy control information and the like are described as descriptors. After the descriptor, a plurality of pieces of stream information regarding each stream included in the multiplexed data are arranged. The stream information includes a stream descriptor in which a stream type, a stream PID, and stream attribute information (frame rate, aspect ratio, etc.) are described to identify a compression codec of the stream. There are as many stream descriptors as the number of streams existing in the multiplexed data.

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

As shown in FIG. 28, the multiplexed data information file is management information of multiplexed data, has a one-to-one correspondence with the multiplexed data, and includes multiplexed data information, stream attribute information, and an entry map.

The multiplexed data information includes a system rate, a reproduction start time, and a reproduction end time as shown in FIG. The system rate indicates a maximum transfer rate of multiplexed data to a PID filter of a system target decoder described later. The ATS interval included in the multiplexed data is set to be equal to or less 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 by adding the playback interval for one frame to the PTS of the video frame at the end of the multiplexed data.

In the stream attribute information, as shown in FIG. 29, 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 the compression codec used to compress the video stream, the resolution of the individual picture data constituting the video stream, the aspect ratio, and the frame rate. It has information such as how much it is. The audio stream attribute information includes the compression codec used to compress the audio stream, the number of channels included in the audio stream, the language supported, and the sampling frequency. With information. These pieces of information are used for initialization of the decoder before the player reproduces it.

In this embodiment, among the multiplexed data, the stream type included in the PMT is used. Also, when multiplexed data is recorded on the recording medium, video stream attribute information included in the multiplexed data information is used. Specifically, in the video encoding method or apparatus shown in each of the above embodiments, the video encoding shown in each of the above embodiments for the stream type or video stream attribute information included in the PMT. 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 discriminate between video data generated by the moving picture encoding method or apparatus described in the above embodiments and video data compliant with other standards.

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 multiplexed data generated by the moving picture encoding method or apparatus described in the above embodiments. To do. When it is determined that the stream type or the video stream attribute information is generated by the moving image encoding method or apparatus described in the above embodiments, in step exS102, the above embodiments are performed. Decoding is performed by the moving picture decoding method shown in the form. If the stream type or video stream attribute information indicates that it conforms to a standard such as conventional MPEG-2, MPEG4-AVC, or VC-1, in step exS103, the conventional information Decoding is performed by a moving image decoding method compliant with the standard.

In this way, by setting a new unique value in the stream type or video stream attribute information, whether or not decoding is possible with the moving picture decoding method or apparatus described in each of the above embodiments is performed. Judgment can be made. Therefore, even when multiplexed data conforming to different standards is input, an appropriate decoding method or apparatus can be selected, and therefore decoding can be performed without causing an error. In addition, the moving picture encoding method or apparatus or the moving picture decoding method or apparatus described in this embodiment can be used in any of the above-described devices and systems.

(Embodiment 8)
The moving picture encoding method and apparatus and moving picture decoding method and apparatus described in the above embodiments are typically realized by an LSI that is an integrated circuit. As an example, FIG. 31 shows a configuration of an LSI ex500 that is made into one chip. The LSI ex500 includes elements ex501, ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 described below, and each element is connected via a bus ex510. The power supply circuit unit ex505 is activated to an operable state by supplying power to each unit when the power supply is on.

For example, when performing the encoding process, the LSI ex500 performs the microphone ex117 and the camera ex113 by the AV I / O ex509 based on the control of the control unit ex501 including the CPU ex502, the memory controller ex503, the stream controller ex504, the drive frequency control unit ex512, and the like. The 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 divided into a plurality of times as appropriate according to the processing amount and the processing speed and sent to the signal processing unit ex507, and the signal processing unit ex507 encodes an audio signal and / or video. Signal encoding is performed. Here, the encoding process of the video signal is the encoding process described in the above embodiments. The signal processing unit ex507 further performs processing such as multiplexing the encoded audio data and the encoded video data according to circumstances, and outputs the result from the stream I / Oex 506 to the outside. The output multiplexed data is transmitted to the base station ex107 or written to the recording medium ex215. It should be noted that data should be temporarily stored in the buffer ex508 so as to be synchronized when multiplexing.

In the above description, the memory ex511 is described as an external configuration of the LSI ex500. However, a configuration included in the LSI ex500 may be used. 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 a plurality of chips.

In the above description, the control unit ex501 includes 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 also in the signal processing unit ex507, the processing speed can be further improved. As another example, the CPU ex502 may be configured to include a signal processing unit ex507 or, for example, 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 a signal processing unit ex507 or a CPU ex502 having a part thereof.

In addition, although it was set as LSI here, it may be called IC, system LSI, super LSI, and ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Furthermore, if integrated circuit technology that replaces LSI emerges as a result of progress in semiconductor technology or other derived technology, it is naturally possible to integrate functional blocks using this technology. Biotechnology can be applied.

(Embodiment 9)
When decoding the video data generated by the moving picture encoding method or apparatus shown in the above embodiments, the video data conforming to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1 is decoded. It is conceivable that the amount of processing increases compared to the case. Therefore, in LSI ex500, it is necessary to set a driving frequency higher than the driving frequency of CPU ex502 when decoding video data compliant with the conventional standard. However, when the drive frequency is increased, there is a problem that power consumption increases.

In order to solve this problem, moving picture decoding devices such as the television ex300 and LSI ex500 are configured to identify which standard the video data conforms to and switch the driving frequency in accordance with 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 image encoding method or apparatus described in 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 compliant with the conventional standard, compared to the case where the video data is generated by the moving picture encoding method or apparatus shown in the above embodiments, Set the drive frequency low. Then, it instructs the decoding processing unit ex802 compliant with the conventional standard to decode the video data.

More specifically, the drive frequency switching unit ex803 includes the CPU ex502 and the drive frequency control unit ex512 in FIG. Also, the decoding processing unit ex801 that executes the moving picture decoding method shown in each of the above embodiments and the decoding processing unit ex802 that complies with the conventional standard correspond to the signal processing unit ex507 in FIG. The CPU ex502 identifies which standard the video data conforms to. Then, based on the signal from the CPU ex502, the drive frequency control unit ex512 sets the drive frequency. Further, based on the signal from the CPU ex502, the signal processing unit ex507 decodes the video data. Here, for the identification of the video data, for example, it is conceivable to use the identification information described in the seventh embodiment. The identification information is not limited to that described in Embodiment 7, and any information that can identify which standard the video data conforms to may be used. For example, it is possible to identify which standard the video data conforms to based on an external signal that identifies whether the video data is used for a television or a disk. In some cases, identification may be performed based on such an external signal. In addition, the selection of the driving frequency in the CPU ex502 may be performed based on, for example, a lookup table in which video data standards and driving frequencies are associated with each other as shown in FIG. The look-up table is 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 look-up table.

FIG. 33 shows steps for executing 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 identifies whether the video data is generated by the encoding method or apparatus described in each of the above embodiments based on the identification information. When the video data is generated by the encoding method or apparatus shown in the above embodiments, in step exS202, the CPU ex502 sends a signal for setting the drive frequency high to the drive frequency control unit ex512. Then, the drive frequency control unit ex512 sets a high drive frequency. On the other hand, if it 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 the signal for setting the drive frequency low. This 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 the above embodiments.

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

In addition, the setting method of the driving frequency may be set to a high driving frequency when the processing amount at the time of decoding is large, and to a low driving frequency when the processing amount at the time of decoding is small. It is not limited to the method. For example, the amount of processing for decoding video data compliant with the MPEG4-AVC standard is larger than the amount of processing for decoding video data generated by the moving picture encoding method or apparatus described in the above embodiments. It is conceivable that the setting of the driving frequency is reversed to that in the case described above.

Furthermore, the method for setting the drive frequency is not limited to the configuration in which the drive frequency is lowered. For example, when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in the above embodiments, the voltage applied to the LSIex500 or the apparatus including the LSIex500 is set high. However, when it is shown that the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc., it is also possible to set the voltage applied to the LSIex500 or the device including the LSIex500 low. It is done. As another example, when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in the above embodiments, the driving of the CPU ex502 is stopped. If the video data conforms to the standards such as MPEG-2, MPEG4-AVC, VC-1, etc., the CPU ex502 is temporarily stopped because there is room in processing. Is also possible. Even when the identification information indicates that the video data is generated by the moving image encoding method or apparatus described in each of the above embodiments, if there is a margin for processing, the CPU ex502 is temporarily driven. It can also be stopped. In this case, it is conceivable to set the stop time shorter than in the case where the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1.

Thus, it is possible to save power by switching the drive frequency according to the standard to which the video data conforms. In addition, when the battery is used to drive the LSI ex500 or the device including the LSI ex500, it is possible to extend the life of the battery with power saving.

(Embodiment 10)
A plurality of video data that conforms to different standards may be input to the above-described 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 support a plurality of standards in order to be able to decode even when a plurality of video data complying with different standards is input. However, when the signal processing unit ex507 corresponding to each standard is used individually, there is a problem that the circuit scale of the LSI ex500 increases 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 embodiments and a decoding conforming to a standard such as MPEG-2, MPEG4-AVC, or VC-1 The processing unit is partly 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 compliant with the MPEG4-AVC standard are processed in processes such as entropy coding, inverse quantization, deblocking filter, and motion compensation. Some contents are common. For the common processing content, the decoding processing unit ex902 corresponding to the MPEG4-AVC standard is shared, and for the other processing content unique to the present invention not corresponding to the MPEG4-AVC standard, the dedicated decoding processing unit ex901 is used. Configuration is conceivable. In particular, since the present invention is characterized by inverse quantization, for example, a dedicated decoding processing unit ex901 is used for inverse quantization, and other entropy coding, deblocking filter, motion compensation, and the like are used. For any or all of the processes, it is conceivable to share the decoding processing unit. Regarding the sharing of the decoding processing unit, regarding the common processing content, the decoding processing unit for executing the moving picture decoding method described in each of the above embodiments is shared, and the processing content specific to the MPEG4-AVC standard As for, a configuration using a dedicated decoding processing unit may be used.

Further, ex1000 in FIG. 35B shows another example in which processing is partially shared. In this example, a dedicated decoding processing unit ex1001 corresponding to processing content unique to the present invention, a dedicated decoding processing unit ex1002 corresponding to processing content specific to other conventional standards, and a moving picture decoding method of the present invention A common decoding processing unit ex1003 corresponding to processing contents common to other conventional video decoding methods is used. Here, the dedicated decoding processing units ex1001 and ex1002 are not necessarily specialized in the processing content specific to the present invention or other conventional standards, and may be capable of executing other general-purpose processing. Also, the configuration of the present embodiment can be implemented by LSI ex500.

As described above, by sharing the decoding processing unit with respect to the processing contents common to the moving picture decoding method of the present invention and the moving picture decoding method of the conventional standard, the circuit scale of the LSI is reduced, and the cost is reduced. It is possible to reduce.

INDUSTRIAL APPLICABILITY The encoding method and decoding method according to the present invention have the effect of reducing the amount of calculation, and are applied to, for example, a video camera, a mobile phone having a video shooting and playback function, a personal computer, or a recording / playback apparatus. Can do.

140 Inverse quantization unit 215 Second inverse transform target determination unit 235 Integration unit 240 Entropy decoding unit 250 First inverse transform unit 260 Second inverse transform unit 301 Bit length control unit 302 Second inverse transform matrix multiplication unit 303 2 inverse transformation shift unit 304 first inverse transformation matrix multiplication unit 305 first inverse transformation shift unit 306 second partial shift unit 310 norm correction multiplication unit 310
311 norm correction shift unit 311
320 Second inverse transformation control unit 321 Second inverse transformation preshift unit

Claims

An entropy decoding step for entropy decoding the encoded signal to generate a plurality of quantized coefficients;
An inverse quantization step of inversely quantizing the plurality of quantized coefficients to generate a decoded transformed output signal;
A second inverse transform is performed on a first partial signal constituting a part of the decoded transform output signal using a transform coefficient of a second inverse transform, and the second inverse transform is performed. A second inverse transform step for generating a partial signal of 1;
The first inverse transform is collectively performed on the first partial signal that has been subjected to the second inverse transform and the second partial signal that has not been subjected to the second inverse transform. A first inverse transform step for performing a first inverse transform using the transform coefficients of:
The shift amount after matrix multiplication of the transform coefficient of the second inverse transform is set in block units so that the maximum bit length of the internal variable necessary for matrix multiplication of the first inverse transform does not exceed a predetermined value. A control step for controlling according to the bit length of the decoded conversion output signal;
A decoding method including:
Calculating the bit length of the decoded conversion output signal in units of blocks;
In the control step,
The bit length calculated for a predetermined block is A, the increased bit length by matrix multiplication of the second inverse transformation is K, the increased bit length by matrix multiplication of the first inverse transformation is D, the first When the maximum bit length in the inverse transformation of MD is MD, the shift amount of MD− (A + D + K) is adjusted after matrix multiplication of the second inverse transformation.
The decoding method according to claim 1.
A conversion step of performing frequency conversion on the input signal and generating a converted output signal having coefficient values of a plurality of frequency components;
A quantization step of quantizing the transformed output signal to generate a plurality of quantization coefficients;
An entropy encoding step of entropy encoding the plurality of quantized coefficients to generate an encoded signal;
An inverse quantization step of inversely quantizing the plurality of quantized coefficients to generate a decoded transformed output signal;
A second inverse transform is performed on a first partial signal constituting a part of the decoded transform output signal using a transform coefficient of a second inverse transform, and the second inverse transform is performed. A second inverse transform step for generating a partial signal of 1;
The first inverse transform is collectively performed on the first partial signal that has been subjected to the second inverse transform and the second partial signal that has not been subjected to the second inverse transform. A first inverse transform step for performing a first inverse transform using the transform coefficients of:
The shift amount after matrix multiplication of the transform coefficient of the second inverse transform is set in block units so that the maximum bit length of the internal variable necessary for matrix multiplication of the first inverse transform does not exceed a predetermined value. A control step for controlling according to the bit length of the decoded conversion output signal;
An encoding method including:
An entropy decoding step for entropy decoding the encoded signal to generate a plurality of quantized coefficients;
An inverse quantization step of inversely quantizing the plurality of quantized coefficients to generate a decoded transformed output signal;
A second inverse transform is performed on a first partial signal constituting a part of the decoded transform output signal using a transform coefficient of a second inverse transform, and the second inverse transform is performed. A second inverse transform step for generating a partial signal of 1;
The first inverse transform is collectively performed on the first partial signal that has been subjected to the second inverse transform and the second partial signal that has not been subjected to the second inverse transform. A first inverse transform step for performing a first inverse transform using the transform coefficients of:
In accordance with the presence or absence of the operations of the vertical inverse transform and the horizontal inverse transform of the second inverse transform so that the maximum bit length of the internal variable required for the matrix multiplication of the first inverse transform does not exceed a predetermined value, A pre-shift down step of down-shifting the first partial signal which is an input signal of the second inverse transform by a predetermined value;
A decoding method including: