JP2009156971A - Encoding device, decoding device, encoding method, decoding method, encoding program, decoding program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a coding amount by attaining a high encoding efficiency for a signal sequence. <P>SOLUTION: The encoding device of the invention includes at least a signal extraction section and a separation signal sequence generation section. A signal extraction section collects (P+n×T)-th signals from input signal sequence Z at an initial phase P and an interval T. The separation signal sequence generation section obtains a maximum digit A in the (P+n×T)-th signals in the signal sequence Z, and generates a sequence (a separation signal sequence X) of a signal composed of the digits of the maximum digit A or less of the (P+n×T)-th signals in the signal sequence Z. The decoding device of the invention receives at least the initial phase P, the interval T, the maximum digit A and the separation signal sequence X and includes at least a restoration section. The restoration section restores each signal of the separation signal sequence X to the (P+n×T)-th signals in the signal sequence Z to be decoded by using the maximum digit A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a signal sequence encoding method, decoding method, apparatus using these methods, a program, and a recording medium.

  As a method for compressing information such as sound and image, lossless encoding without distortion is known. In addition, when a waveform is recorded as a linear PCM signal as it is, various compression encodings have been devised (Non-Patent Document 1).

On the other hand, for long-distance transmission of telephones and voice transmission for VoIP, logarithmic approximate companding PCM (Non-patent Document 2) in which the amplitude is approximated to a logarithm is used instead of the linear PCM with the amplitude as it is. ing. In addition, G. is a typical logarithmic approximate companding PCM (Non-patent Document 2). There is also a technique for mapping the code of 711 to a linear numerical value (unsigned 8-bit value) (Non-Patent Document 3). Furthermore, there is a technique for reducing the code amount by utilizing the fact that many of the upper digits are “0” when the volume is low (Patent Document 1). In Patent Document 1, the maximum absolute value is obtained for each frame, digits larger than the maximum value are omitted, and only valid digits are encoded.
Mat Hans, “Lossless Compression of Digital Audio”, IEEE SIGNAL PROCESSING MAGAZINE, July 2001, pp.21-32. ITU-T Recommendation G.711, “Pulse Code Modulation (PCM) of Voice Frequencies”. Florin Ghido, and Ioan Tabus, “ACCOUNTING FOR COMPANDING NONLINEARITIES IN LOSSLESS AUDIO COMPRESSION”, in ICASSP 2007 Proceedings, pp.I-261-I-264 IEEE, 2007. JP 2003-332914 A

  When a VoIP system becomes widespread instead of a general telephone, the transmission capacity required for voice transmission for VoIP increases. For example, ITU-T G. In the case of 711, a transmission capacity of 64 kbit / s × 2 is required for one line, but the required transmission capacity increases as the number of lines increases. Accordingly, there is a need for a technique (a technique that can reduce the amount of code) that compresses and encodes a stretched signal sequence such as logarithmic approximate companding PCM. The companding means that the magnitude relationship (magnitude) of the original signal is indicated by a number series. The number series indicating the magnitude relation (magnitude) of the original signal is a number given at equal intervals while maintaining the magnitude relation or inverting the magnitude relation. In addition, the number series indicating the magnitude relationship (magnitude) of the original signal includes a case where two different numbers are assigned to the magnitude (eg, “0”) of one original signal. FIG. 1 is a diagram illustrating an example of the amplitude of the second signal sequence. The horizontal axis is a value in the case of linear PCM, and the vertical axis is a corresponding value in the case of logarithmic approximate companding PCM. FIG. 2 is a diagram showing a specific form of the 8-bit μ-rule. It consists of 1 bit (polarity) indicating positive / negative, 3 bits (exponent part) indicating exponent (slope), and 4 bits (linear part) indicating increment in a linear code. In the case of this type of logarithmic approximate companding PCM, numerical values from −127 to 127 can be expressed. This corresponds to linear PCM from -8158 to 8158 (FIG. 1). The “signal” used in the present specification means, for example, a “bit string” as shown in FIG. 2, and the “signal string” is a series of a plurality of such signals (for example, , A series of 160 signals). In each bit constituting the signal (bit string), the number of bits expressing the absolute value of the amplitude of the signal is expressed by “digit”. In the example of FIG. 2, bit number 8 is the first digit, and bit number 2 is the largest digit (seventh digit). Since bit number 1 is a bit representing polarity, it is not considered when considering digits.

  Therefore, G. It is conceivable to perform lossless compression on the expanded signal sequence such as 711. However, it cannot be said that the compression efficiency is sufficiently high even if the compressed signal train is simply reversibly compressed. Further, the method of Patent Document 1 can reduce the code amount only when the sound volume is low to some extent, and is not generally applicable.

  The present invention has been made in view of such a situation, and an object of the present invention is to realize high coding efficiency and reduce the amount of codes for a signal sequence. It is another object of the present invention to effectively reduce the amount of codes, particularly for a signal train that has been companded.

  The encoding device of the present invention includes at least a signal extraction unit and a separated signal sequence generation unit. The signal extraction unit has an initial phase P (where P is an integer greater than or equal to 0) and an interval T (where T is an integer greater than or equal to 2), and the (P + n × T) th signal (where , N is an integer greater than or equal to 0 and P + n × T is smaller than the number of signals in the signal sequence Z). The separated signal sequence generation unit obtains the maximum digit A in the (P + n × T) th signal of the signal sequence Z. Then, a signal sequence (separated signal sequence X) composed of digits equal to or less than the maximum digit A of the (P + n × T) -th signal in the signal sequence Z is generated. The decoding apparatus of the present invention receives at least the initial phase P (where P is an integer greater than or equal to 0), the interval T (where T is an integer greater than or equal to 2), the maximum digit A, and the separated signal sequence X, At least a restoration unit is provided. The restoration unit (P + n × T) -th signal of the signal sequence Z to be decoded using the maximum digit A for each signal of the separated signal sequence X (where n is 0 or more and P + n × T is a signal sequence) To an integer smaller than the number of Z signals). In the above-described encoding device and decoding device, only the configuration necessary for generating at least one separated signal sequence X is limited, and the other configurations are not limited.

Examples of the encoding device and decoding device that are limited to include generation of one or more separated signal sequences and handling of signals that are not targeted (remaining signals) include the following. Similarly, the encoding device may include a signal extraction unit and a separated signal sequence generation unit. For each combination of M phases (where M is an integer of 1 or more) initial phase P _m (where m is an integer from 1 to M) and interval T _m , the signal extraction unit ( P _m + n × T _m ) th signal (where n is 0 or more and P _m + n × T _m is an integer smaller than the number of signals in the signal sequence Z). Further, a residual signal sequence Y is generated by deleting all (P _m + n × T _m ) th signals from the signal sequence Z. Separation signal string generating unit, for each combination of initial phase _{P m} and intervals _{T m,} obtains the most significant _{A m} in the _{(P m + n × T m} ) th signal of the signal sequence Z. Then, to produce a _{(P m + n × T m} ) th most significant _{A m} consisting of the following digit signal sequence of the signal (separated signal sequence _{X m)} of the signal sequence Z. The decoding apparatus receives the residual signal sequence Y, M sets of initial phases P _m , interval T _m , maximum digit _Am, and separated signal sequence X _m , and decodes the signal sequence Z. The decoding device includes a restoration unit and an insertion unit. Recovery unit, a separation signal sequence _{X m,} the most significant with _{A m} of the signal sequence _{Z (P m + n × T} m) th signal (where, n is an 0 or _{more, P} m + n × T _m is an integer smaller than the number of signals in the signal sequence Z). The inserting unit inserts the restored signal into the residual signal sequence Y so as to be the (P _m + n × T _m ) th signal of the signal sequence Z, and obtains the signal sequence Z.

Note that the combination of the initial phase P _m and the interval T _m may be determined in advance. Moreover, you may select the combination estimated that encoding efficiency is good from several types defined beforehand. Alternatively, a combination of the initial phase P _m and the interval T _m may be obtained by analyzing the input signal sequence Z.

Further, all the signals including the maximum digit in the signal sequence Z may be extracted by the combination of the initial phase P _m and the interval T _m , and a signal having a digit smaller than the maximum digit in the signal sequence Z may be left. In this case, the residual signal sequence Y may be a signal sequence composed of digits of the maximum digit A or less.

  According to the encoding device and the decoding device of the present invention, signals having a small maximum digit are collected, and a signal sequence including only valid digits (digits less than the maximum digit) is created. That is, since a digit (bit) larger than an effective digit can be deleted, the code amount can be reduced.

  First, the principle of the present invention will be described with reference to FIGS. FIG. 3 is a diagram showing an image of the principle of the present invention, and FIG. 4 is an image of a code generated by the present invention. The circles in FIG. 3 mean each signal, the black circle signal is a signal of the same format as the signal sequence Z, and the white circle is a signal consisting only of digits less than the maximum digit of the signal belonging to the signal sequence. is there.

FIG. 3A shows an example in which signals are collected from the signal sequence Z at an initial phase 1 and an interval 4. The separated signal sequence X is a signal sequence in which signals composed of only digits less than the maximum digit in the collected signals are arranged. The residual signal sequence Y is a remaining signal sequence obtained by removing the separated signal sequence X from the signal sequence Z. FIG. 3B shows a case where {2, 3} and {1, 6} are collected from the signal sequence Z as combinations of {initial phase, interval}, respectively. The separated signal string X ₁ is a signal string in which signals composed of only digits less than the maximum number of the signals collected at the initial phase 2 and the interval 3 are arranged. Separation signal sequence X ₂ are initial phases 1, a signal sequence arranged the maximum number of digits signal consisting only of digits in the collected signal at intervals 6. Residual signal sequence Y is the remainder of the signal sequence removed separation signal sequence X ₁ and the separation signal sequence X ₂ from the signal sequence Z.

  In order to restore the separated signal string to the original signal string, the presence / absence of separation, the number of separated signal strings, the initial phase for each separated signal string, the interval, the maximum digit, and the separated signal string A sign is required. If there is no separation when the number of separated signal sequences is 0, the signal indicating the presence or absence of separation can be omitted. These pieces of information may be variable length encoded as shown in FIG.

  According to the principle of the present invention, signals having a small maximum digit are periodically collected, and a signal sequence (separated signal sequence) consisting only of valid digits (digits below the maximum digit) is created. That is, since a digit (bit) larger than an effective digit can be deleted, the code amount can be reduced. Specifically, if the amount of codes larger than the amount of codes of auxiliary information (initial phase, interval, and maximum digit) necessary for restoring the separated signal sequence can be reduced, the overall code amount can be reduced.

  For example, when a signal sequence Z consisting of 160 samples (one frame) is separated at an interval of 4, the number of signals in the separated signal sequence X is 40. When the maximum digit of the signal in this separated signal sequence is one digit smaller than the maximum digit of all signals, 40 bits are saved. On the other hand, if 8 bits are required for the initial phase, interval, and maximum digit information, the subtraction of 32 bits can be reduced. In this way, it is possible to determine whether the effect of reducing the code amount can be obtained by analyzing the signals constituting the separated signal sequence.

  Further, as a method for estimating whether or not the effect of code amount reduction can be obtained, there is the following method. In the signal in the frame, the number of “1” (“0” in the case of a code with an inverted bit) is checked in the maximum digit position. It is estimated that an effect can be obtained by generating the column X, and if it is larger than the threshold value, it is estimated that the effect cannot be obtained.

  Specific embodiments are shown below. In the following description, components having the same function and process steps for performing the same process are assigned the same number to avoid duplication of description, and description thereof is omitted.

[First Embodiment]
FIG. 5 shows an example of a functional configuration of the encoding apparatus according to the first embodiment, and FIG. 6 shows an example of a processing flow of the encoding apparatus according to the first embodiment. Encoding apparatus 100 includes a signal extraction unit 110 separates the signal sequence generation unit ₁₂₀ 1, ..., and a 120 _M. The signal extraction unit 110 has predetermined M sets (where M is an integer of 1 or more) of initial phases P _m (where P is an integer of 0 or more, m is an integer from 1 to M) and an interval T _m. For each combination (where T is an integer of 2 or more), the (P _m + n × T _m ) th signal from the input signal sequence Z (where n is 0 or more and P _m + n × T _m Are integers smaller than the number of signals in the signal sequence Z) and output. Further, a residual signal sequence Y is generated by deleting all (P _m + n × T _m ) th signals from the signal sequence Z (S110). Separating the signal sequence generation unit 120 _m determines the maximum digit _{A m} in the _{(P m + n × T m} ) th signal of the signal sequence Z. Then, to produce a _{(P m + n × T m} ) th most significant _{A m} consisting of the following digit signal sequence of the signal (separated signal sequence _{X m)} of the signal sequence Z (S120 _m). Encoding apparatus 100, the number M of the separated signal sequence _{X m,} the residual signal sequence Y and the separated signal sequence _{X m} for each of the initial phase _{P m} and the interval _{T m} and maximum length _{A m} and the separated signal sequence _{X m} Should be output. As specific combinations of the initial phase P _m and the interval T _m , for example, {P _m , T _m } = {0, 4}, {1, 4}, {2, 4}, {3,4} It may be four sets to fix the interval _{T m (M} = 4) as. Alternatively, {P _m , T _m } = {0, 2}, {1, 2}, {0, 3}, {1, 3}, {2, 3}, {0, 4}, {1, 4 }, {2,4}, {3,4}, {0,5}, {1,5}, {2,5}, {3,5}, the initial phase _{P m} as {4,5} And 14 sets (M = 14) in which the interval _{Tm is} also changed.

FIG. 7 shows an example of a functional configuration of the decoding apparatus according to the first embodiment, and FIG. 8 shows an example of a processing flow of the decoding apparatus according to the first embodiment. Decoding apparatus 700 receives residual signal sequence Y, M sets of initial phases P _m , interval T _m , maximum digit _Am, and separated signal sequence X _m as input, and decodes signal sequence Z. The decryption apparatus 700 includes a restoration unit 720 ₁ ,..., 720 _M and an insertion unit 710. Restorer 720 _m is a separation signal sequence _{X m,} the most significant with _{A m} of the signal sequence _{Z (P m + n × T} m) th signal (where, n is an 0 or _{more, P} m + n × _{T m} is restored to an integer) which is smaller than the number of signal signal sequence Z (S720 _m). The insertion unit 710 inserts the restored signal into the residual signal sequence Y so as to be the (P _m + n × T _m ) th signal of the signal sequence Z, and obtains the signal sequence Z (S710).

According to the encoding device and the decoding device of the present embodiment, signals having a small maximum digit are periodically collected, and a signal sequence (separated signal sequence) including only valid digits (digits less than the maximum digit) is created. That is, since a digit (bit) larger than an effective digit can be deleted, the code amount can be reduced. Specifically, if the amount of codes larger than the amount of auxiliary information (initial phase P _m , interval T _m, and maximum digit A _m ) necessary for restoring the separated signal sequence can be reduced, the overall code amount is reduced. Can be reduced.

[Modification]
The configuration necessary for obtaining the effect of the present invention as in the first embodiment is a configuration necessary for generating the first separated signal sequence. Even if there is no configuration for generating the second and subsequent separated signal sequences, the effect can be obtained. Further, the handling of the residual signal need not be limited to the above-described method. Therefore, the limitations on the minimum components necessary for obtaining the effects of the present invention are as follows.

  The encoding device includes a signal extraction unit and a separated signal sequence generation unit. The signal extraction unit has an initial phase P (where P is an integer greater than or equal to 0) and an interval T (where T is an integer greater than or equal to 2), and the (P + n × T) th signal (where , N is an integer greater than or equal to 0 and P + n × T is smaller than the number of signals in the signal sequence Z). The separated signal sequence generation unit obtains the maximum digit A in the (P + n × T) th signal of the signal sequence Z. Then, a signal sequence (separated signal sequence X) composed of digits equal to or less than the maximum digit A of the (P + n × T) -th signal in the signal sequence Z is generated. The decoding apparatus of the present invention receives at least the initial phase P (where P is an integer greater than or equal to 0), the interval T (where T is an integer greater than or equal to 2), the maximum digit A, and the separated signal sequence X, A restoration unit is provided. The restoration unit (P + n × T) -th signal of the signal sequence Z to be decoded using the maximum digit A for each signal of the separated signal sequence X (where n is 0 or more and P + n × T is a signal sequence) To an integer smaller than the number of Z signals).

[Second Embodiment]
FIG. 9 shows a functional configuration example of the encoding apparatus of the second embodiment, and FIG. 10 shows an example of a processing flow of the encoding apparatus of the second embodiment. The encoding apparatus 200 includes a signal extraction unit 210, a separated signal sequence generation unit 120 ₁ ,..., 120 _M , and a selection unit 240.

The selection unit 240 records in advance V separation methods (combination of M _v sets of initial phases and intervals {P _v1 , T _v1 }, ..., {P _vM , T _vM }) (where v is An integer of 1 or more and V or less, V is an integer of 2 or more). The selection unit 240 selects a separation method one by one (S241). For example, V = 2, and the first separation method is {P _1m , T _1m } = {0, 4}, {1, 4}, {2, 4}, {3,4]} The separation method is {P _2m , T _2m } = {{0, 5}, {1, 5}, {2, 5}, {3, 5}, {4, 5}. Then, the signal sequence Z is analyzed to estimate the effect of code amount reduction (S242). When the selection unit 240 estimates the effects for all the separation methods, the separation method that is estimated to be most effective is the combination of M sets of initial phases and intervals {P ₁ , T ₁ },. _M , T _M } is output (S245). Note that the estimation of the effect of code amount reduction in step S242 can be realized by collecting the signals that actually constitute the separated signal sequence and obtaining the maximum digit. For example, when a signal sequence Z consisting of 160 samples (one frame) is separated at an interval of 4, the number of signals in the separated signal sequence X is 40. When the maximum digit of the signal in this separated signal sequence is one digit smaller than the maximum digit of all signals, 40 bits are saved. On the other hand, if 8 bits are required for the initial phase, interval, and maximum digit information, the subtraction of 32 bits can be reduced. Thus, by analyzing the signals constituting the separated signal sequence, the effect of reducing the code amount can be estimated.

The signal extraction unit 210 collects and outputs the (P _m + n × T _m ) th signal from the input signal sequence Z for each combination of the M sets of initial phases P _m and intervals T _m output by the selection unit 240. To do. Further, a residual signal sequence Y is generated by deleting all (P _m + n × T _m ) th signals from the signal sequence Z (S210). The processing of the separation signal sequence generation unit 120 _m is the same as that in the first embodiment. Further, the decoding device of the second embodiment is the same as the decoding device (FIGS. 7 and 8) of the first embodiment.

  Since the encoding device and the decoding device according to the second embodiment have such a configuration, a more efficient separation method than that of the first embodiment can be selected, and the amount of codes can be reduced.

[Modification]
Encoding apparatus of the second embodiment, to produce a separated signal sequence X _m separation method selected by the selection unit 240. However, it does not generate a separate signal sequence X _m, can in some cases the code amount is small. Encoding apparatus of the present modification also performs determination of whether to generate a separated signal sequence X _m. FIG. 9 shows a functional configuration example of the encoding apparatus according to the second embodiment, and FIG. 11 shows a processing flow example of the encoding apparatus according to the second embodiment. The encoding apparatus 300 includes a signal extraction unit 310, a separated signal sequence generation unit 120 ₁ ,..., 120 _M , and a selection unit 240. The processing of the selection unit 240 is the same as that of the encoding device 200. The signal extraction unit 310 has the effect of reducing the code amount with the combination {P ₁ , T ₁ },..., {P _M , T _M } of M sets of initial phases and intervals estimated by the selection unit 240 to be most effective. It is determined whether it can be obtained (S311). The determination of whether or not there is an effect may be performed by the same method as the estimation of the effect of code amount reduction in step S242, or the estimation result in step S242 may be used. When the effect is obtained, the signal extraction unit 310 calculates (P _m + n × T _m) from the input signal sequence Z for each combination of the M sets of initial phases P _m and intervals T _m output from the selection unit 240. ) Collect and output the 2nd signal. Further, a residual signal sequence Y is generated by deleting all (P _m + n × T _m ) th signals from the signal sequence Z (S210). When the effect cannot be obtained, the signal extraction unit 310 does not perform the process of collecting the (P _m + n × T _m ) th signal from the signal sequence Z, and outputs the signal sequence Z as it is (S315). In this case, the encoding apparatus 300 may output by substituting 0 for M, or may be output with a code indicating “no division” added to the bit indicating whether there is division in FIG.

The processing of the separation signal sequence generation unit 120 _m is the same as that in the first embodiment. Further, the decoding device of the second embodiment is the same as the decoding device (FIGS. 7 and 8) of the first embodiment.

  Since the encoding device and the decoding device according to the modification of the second embodiment have such a configuration, when the code amount can be reduced by separation, the same effect as the second embodiment can be obtained, and the effect cannot be obtained by the division. Do not divide. Therefore, the amount of codes can be reduced more efficiently than in the second embodiment.

[Third Embodiment]
FIG. 12 shows an example of a functional configuration of the encoding apparatus according to the third embodiment, and FIG. 13 shows an example of a processing flow of the encoding apparatus according to the third embodiment. The encoding apparatus 400 includes a signal extraction unit 410, a separated signal sequence generation unit 120 ₁ ,..., 120 _M , and an analysis unit 440. FIG. 14 shows a processing flow example of the analysis unit 440. The analysis unit 440 records the combination of the initial phase and the interval {P _h , T _h } in advance (where h is an integer from 1 to H, and H is an integer from 1). The analysis unit 440 first obtains the maximum digit in the signal sequence Z and the position U _j of the signal of the maximum digit (where j is an integer between 1 and J, and J is the number of signals having the maximum digit) ( S441). Next, select the one interval _{The T g} is in the combination of initial phase and interval are pre-recorded {P, T} (S442) . j = 1 is set (S443). The position U _j is divided by T _g to obtain the excess and set as the initial phase P _g (S445). When there is a combination of the initial phase and interval {P _h , T _h } recorded in advance that matches the combination {P _g , T _g } of the initial phase and interval obtained in step S445. The combination is deleted from the combination {P _h , T _h } of the initial phase and interval recorded in advance (S446). It is confirmed whether j = J (S447). If step S447 is No, j + 1 is substituted for j (S448), and the process returns to step S445. If step S447 is Yes, it is checked whether the select all intervals _{The T g} is in the combination of initial phase and interval are pre-recorded {P, T} (S449) . Step S449 is No, the process returns to step S442, selects an interval _{The T g} not selected (S442). If step S449 is Yes, the number M of remaining initial phase and interval combinations and the combination {P _m , T _m } are output (S450). When there is no combination of the remaining initial phase and interval (M = 0), there is no effect due to separation.

The signal extraction unit 410 confirms whether there is an effect due to the separation (S411). Specifically, it is confirmed whether there is a combination of the remaining initial phase and interval. If there is an effect, the (P _m + n × T _m ) -th signal is collected from the input signal sequence Z for each combination of the M sets of initial phases P _m and intervals T _m output from the analysis unit 440. Further, a residual signal sequence Y is generated by deleting all (P _m + n × T _m ) th signals from the signal sequence Z (S110). If there is no effect, the subsequent processing is the same as that of the second embodiment. The decoding device is the same as that in the first embodiment.

According to the encoding apparatus of the third embodiment, it is possible to find a combination of the initial phase P _m and the interval T _{m from which} the effect of reducing the code amount can be obtained. Therefore, the code amount can be reduced more efficiently.

[Fourth Embodiment]
FIG. 12 shows an example of a functional configuration of the encoding apparatus of the fourth embodiment, and FIG. 13 shows an example of a processing flow of the encoding apparatus of the fourth embodiment. The encoding apparatus 500 includes a signal extraction unit 510, a separated signal sequence generation unit 120 ₁ ,..., 120 _M , and an analysis unit 540. The analysis unit 540 analyzes the signal sequence Z (S440). For example, in the signal in the frame, the number of “1” (“0” in the case of a code with inverted bits) is checked at the position of the maximum digit. The signal extraction unit 410 determines that an effect is obtained if the ratio of “1” in the position of the maximum digit is equal to or less than a threshold (for example, 10%), and determines that the effect cannot be obtained if the ratio is greater than the threshold. (S511). Subsequent processing when it is determined that there is an effect is the same as in the first embodiment. Further, the subsequent processing when it is determined that there is no effect is the same as that of the second embodiment modification. The decoding device is the same as that in the first embodiment. The encoding device of the fourth embodiment can easily determine the effect of separation in this way.

[Fifth Embodiment]
The fifth embodiment is an example in which the encoding device and the decoding device of the first to fourth embodiments are used for encoding and decoding of a prediction residual sequence of lossless linear prediction encoding. FIG. 15 shows a functional configuration example of the encoding apparatus according to the fifth embodiment, and FIG. 16 shows an example of a processing flow of the encoding apparatus according to the fifth embodiment. The encoding device 600 includes a linear prediction unit 610, a quantization unit 620, a predicted value calculation unit 630, a subtraction unit 640, a coefficient encoding unit 650, and the encoding device 100 (or 200, 300, 400, 500).

When the signal sequence S = {s (1), s (2),..., S (L)} divided into frames is input to the encoding apparatus 600, the linear prediction unit 610 divides into frames. The linear prediction coefficient K = {k (1), k (2),..., K (P)} is obtained from the signal sequence S (S610). Note that P is the predicted order. The quantization unit 620 quantizes the linear prediction coefficient K to obtain a quantized linear prediction coefficient K ′ = {k ′ (1), k ′ (2),..., K ′ (P)} (S620). The predicted value calculation unit 630 uses the second signal sequence X and the quantized linear prediction coefficient K ′ to generate the second predicted value sequence Y = {y (1), y (2),. (L)} is obtained (S630).

However, j is an integer of 1 or more and L or less. The subtraction unit 640 obtains a signal sequence (predicted residual sequence) X = {x (1), x (2),..., X (L)} between the signal sequence S and the predicted value sequence Y (S640). . The coefficient encoding unit 650 encodes the quantized linear prediction coefficient K ′ and outputs a prediction coefficient code C _k (S650). Encoding apparatus 100 (or, 200, 300, 400, 500) encodes the signal sequence X, and the number M of the separated signal sequence _{X m,} the residual signal sequence Y and the initial phase of each of the separation signal sequence _{X m} P _m , interval T _m , maximum digit A _m, and each separated signal sequence X _m are output (S100).

FIG. 17 shows a functional configuration example of the decoding apparatus of the fifth embodiment, and FIG. 18 shows an example of a processing flow of the decoding apparatus of the fifth embodiment. The decoding apparatus 800 includes a decoding apparatus 700, a coefficient decoding unit 820, a predicted value calculation unit 830, and an addition unit 840. The decoding apparatus 700 includes the number M of the separated signal sequences X _m , the residual signal sequence Y, the initial phase P _m for each of the separated signal sequences X _m , the interval T _m , the maximum digit _Am, and each separated signal sequence X _m. , And a signal sequence X = {x (1), x (2),..., X (L)} corresponding to the prediction residual sequence is obtained (S700). The coefficient decoding unit 820 decodes the prediction coefficient code C _k to obtain a quantized linear prediction coefficient K ′ (S820). The predicted value calculation unit 830 obtains the predicted value sequence Y using the decoded signal sequence X and the quantized linear prediction coefficient K ′ as in the following equation (S830).

加算部８４０は、予測値列Ｙと信号列Ｘとを加算して信号列Ｓを求める（Ｓ８４０）。

The adding unit 840 adds the predicted value sequence Y and the signal sequence X to obtain the signal sequence S (S840).

  The encoding device 600 and the decoding device 800 use the encoding device 100 (or 200, 300, 400, 500) and the decoding device 700 to encode and decode a prediction residual sequence of lossless linear prediction encoding. It is an example using. Since the signal sequence to be encoded is a prediction residual sequence, the probability of occurrence near 0 is high. Therefore, since there is a high possibility that the maximum digit is small, there is a high possibility that the code amount can be reduced by applying the present invention.

[Sixth Embodiment]
FIG. 19 shows a functional configuration example of the encoding apparatus according to the sixth embodiment, and FIG. 20 shows a processing flow example of the encoding apparatus according to the sixth embodiment. In the present embodiment, all signals including the maximum digit in the signal sequence Z are extracted by the combination of the initial phase P _m and the interval T _m , and a signal having a digit smaller than the maximum digit in the signal sequence Z is left. The encoding apparatus 1100 includes a signal extraction unit 1110 and a residual signal sequence generation unit 1120. The signal extraction unit 1110 includes M groups (where M is an integer of 1 or more) initial phases P _m (where P is an integer of 0 or more, m is an integer from 1 to M) and an interval T _m (where T is For each combination of two or more integers, the (P _m + n × T _m ) th signal from the input signal sequence Z (where n is 0 or more and P _m + n × T _m is equal to the signal sequence Z) (An integer smaller than the number of signals) is collected (S1110). The residual signal sequence generation unit 1120 deletes all (P _m + n × T _m ) th signals from the signal sequence Z, and the maximum digit A in the remaining signal (however, the digit is the absolute value of the amplitude of the signal) And a signal sequence (residual signal sequence Y) composed of digits less than the maximum digit A of the remaining signal is generated (S1120).

FIG. 21 shows a functional configuration example of the decoding apparatus according to the sixth embodiment, and FIG. 22 shows a processing flow example of the decoding apparatus according to the sixth embodiment. Decoding apparatus 1700 receives residual signal sequence Y, maximum digit A, M sets of initial phases P _m , interval T _m and separated signal sequence X _m and decodes signal sequence Z. Decoding apparatus 1700 includes restoration unit 1720 and insertion unit 1710. The restoration unit 1720 restores the residual signal sequence Y to a signal other than the (P _m + n × T _m ) th signal in the signal sequence Z using the maximum digit A (S1720). Insertion portion 1710, the reconstructed signal, inserts a separate signal sequence _{X m} so that _{(P m + n × T m} ) th signal of the signal sequence Z (S1710).

  As described above, the encoding device and the decoding device of the present embodiment can collect signals with small digits on the residual signal sequence side, and can reduce the amount of codes as in the other embodiments. That is, signals with a small maximum digit may be collected periodically as in the first to fifth embodiments, or signals with a large maximum digit are collected periodically as in the sixth embodiment, and the maximum digit is You may leave a small signal. Eventually, in both cases, signals with a small maximum digit are collected, and digits (bits) larger than the effective digits can be deleted, so that the amount of codes can be reduced.

  Even in the case of a method for leaving a signal having a small maximum digit, the modifications shown in the second to fifth embodiments are possible.

  FIG. 23 shows a functional configuration example of a computer. In the encoding method and decoding method of the present invention, the recording unit 2020 of the computer 2000 reads a program for operating the computer 2000 as each component of the present invention, and the control unit 2010, the input unit 2030, the output unit 2040, etc. By operating, it can be executed by a computer. In addition, as a method of causing the computer to read, the program is recorded on a computer-readable recording medium, and the program recorded on the server or the like is read into the computer through a telecommunication line or the like. There is a method to make it.

The figure which shows the example of the amplitude of the signal train which was drawn. The figure which shows the specific format of 8-bit micro rule. The figure which shows the image of the principle of this invention. The figure which shows the image of the code | symbol produced | generated by this invention. The figure which shows the function structural example of the encoding apparatus of 1st Embodiment. The figure which shows the example of a processing flow of the encoding apparatus of 1st Embodiment. The figure which shows the function structural example of the decoding apparatus of 1st Embodiment. The figure which shows the example of a processing flow of the decoding apparatus of 1st Embodiment. The figure which shows the function structural example of the encoding apparatus of 2nd Embodiment and 2nd Embodiment modification. The figure which shows the example of a processing flow of the encoding apparatus of 2nd Embodiment. The figure which shows the example of a processing flow of the encoding apparatus of 2nd Embodiment modification. The figure which shows the function structural example of the encoding apparatus of 3rd Embodiment and 4th Embodiment. The figure which shows the example of a processing flow of the encoding apparatus of 3rd Embodiment and 4th Embodiment. The figure which shows the example of a processing flow of the analysis part 440. FIG. The figure which shows the function structural example of the encoding apparatus of 5th Embodiment. The figure which shows the example of a processing flow of the encoding apparatus of 5th Embodiment. The figure which shows the function structural example of the decoding apparatus of 5th Embodiment. The figure which shows the example of a processing flow of the decoding apparatus of 5th Embodiment. The figure which shows the function structural example of the encoding apparatus of 6th Embodiment. The figure which shows the example of a processing flow of the encoding apparatus of 6th Embodiment. The figure which shows the function structural example of the decoding apparatus of 6th Embodiment. The figure which shows the example of a processing flow of the decoding apparatus of 6th Embodiment. The figure which shows the function structural example of a computer.

Explanation of symbols

100, 200, 300, 400, 500, 600, 1100 Encoder 110, 210, 310, 410, 510, 1110 Signal extraction unit 120, 1120 Separated signal sequence generation unit 240 Selection unit 440, 540 Analysis unit 610 Linear prediction unit 620 Quantization unit 630 Predicted value calculation unit 640 Subtraction unit 650 Coefficient encoding unit 700, 800, 1700 Decoding device 710, 1710 Insertion unit 720, 1720 Restoration unit 820 Coefficient decoding unit 830 Prediction value calculation unit 840 Addition unit

Claims (20)

The initial phase P _m (where P is an integer greater than or equal to 0, m is an integer from 1 to M) and the interval T _m (where T is an integer greater than or equal to 2) of M pairs (where M is an integer greater than or equal to 1) For each combination, the (P _m + n × T _m ) th signal from the input signal sequence Z (where n is 0 or more and P _m + n × T _m is smaller than the number of signals in the signal sequence Z). And a signal extraction unit that generates a residual signal sequence Y in which all (P _m + n × T _m ) th signals are deleted from the signal sequence Z.
For each combination of the initial phase P _m and the interval T _m , the maximum digit A _{m in} the (P _m + n × T _m ) th signal of the signal sequence Z (where the digit represents the absolute value of the amplitude of the signal) the bits) determined, the signal sequence _{Z (P m + n × T} m) th most significant a _m consisting of the following digit signal sequence of the signal (separated signal sequence X _m) separated signal sequence generation unit which generates a An encoding device comprising: The encoding device according to claim 1, comprising:
A combination of the initial phase P _vm and the interval T _vm of the M _v group (where v is an integer of 1 or more and V or less and V is an integer of 2 or more) is recorded in advance in V types.
Using the input signal sequence Z, a combination of M _v sets of initial phases P _vm and intervals T _vm estimated to have the best coding efficiency among the V types is obtained, and these are determined as the initial values of the M sets. An encoding device that also includes a selection unit that is a combination of the phase P _m and the interval T _m . The encoding device according to claim 1 or 2, comprising:
The signal extraction unit outputs the signal sequence Z when the encoding efficiency is better when the input signal sequence Z is not separated. The encoding device according to claim 1, comprising:
Obtaining the maximum digit in the signal sequence Z and the position U _{j of the} signal having the maximum digit (where j is an integer from 1 to J and J is the number of signals having the maximum digit);
For each predetermined t, the position U _j is sequentially divided to obtain a remainder p, and among a plurality of predetermined initial phase / interval combinations {P, T}, those that match the combination {p, t} Delete it,
When the combination {P, T} of the initial phase and the interval remains, the remaining combination {P, T} of the initial phase and the interval is set as a combination of the M sets of initial phases P _m and the interval T _m. The department also has
When the combination {P, T} of the initial phase and the interval does not remain, the signal extraction unit outputs a signal sequence Z. An initial phase P (where P is an integer greater than or equal to 0) and an interval T (where T is an integer greater than or equal to 2) and the (P + n × T) th signal from the input signal sequence Z (where n is greater than or equal to 0) A signal extraction unit that collects (P + n × T is an integer smaller than the number of signals in the signal sequence Z);
The maximum digit A in the (P + n × T) th signal of the signal sequence Z (where the digit is a bit representing the absolute value of the amplitude of the signal) is obtained, and the (P + n × T) th digit of the signal sequence Z is obtained. And a separated signal sequence generation unit that generates a signal sequence (separated signal sequence X) composed of digits less than or equal to the maximum digit A of the signal. Residual signal sequence Y, M phases (where M is an integer greater than or equal to 1), initial phase P _m (where P is an integer greater than or equal to 0, m is an integer between 1 and M), and interval T _m (where T is 2 is a decoding device for decoding a signal sequence Z by inputting a maximum digit A _m (where a digit is a bit representing the absolute value of the amplitude of a signal) and a separated signal sequence X _m. ,
The separated signal sequence _{X m,} the most significant _{A m} by using the signal sequence _{Z (P m + n × T} m) th signal (where, n is an 0 or _{more, P m} + n × _T m is the signal sequence A restoring unit that restores to an integer smaller than the number of Z signals,
An insertion unit that inserts the restored signal into the residual signal sequence Y so as to be the (P _m + n × T _m ) th signal of the signal sequence Z;
A decoding device comprising: A decoding device that receives an initial phase P (where P is an integer greater than or equal to 0), an interval T (where T is an integer greater than or equal to 2), a maximum digit A, and a separated signal sequence X;
Each signal of the separated signal sequence X is the (P + n × T) th signal (however, n) of the signal sequence Z to be decoded using the maximum digit A (where the digit is a bit representing the absolute value of the amplitude of the signal). Is a decoding unit provided with a restoration unit for restoring P + n × T to an integer smaller than the number of signals in the signal sequence Z). The initial phase P _m (where P is an integer greater than or equal to 0, m is an integer from 1 to M) and the interval T _m (where T is an integer greater than or equal to 2) of M pairs (where M is an integer greater than or equal to 1) For each combination, the (P _m + n × T _m ) th signal from the input signal sequence Z (where n is 0 or more and P _m + n × T _m is smaller than the number of signals in the signal sequence Z). And a signal extraction step of generating a residual signal sequence Y in which all (P _m + n × T _m ) th signals are deleted from the signal sequence Z,
For each combination of the initial phase P _m and the interval T _m , the maximum digit A _{m in} the (P _m + n × T _m ) th signal of the signal sequence Z (where the digit represents the absolute value of the amplitude of the signal) separation signal sequence generating step of bit) is obtained, to produce a _{(P m + n × T m} ) th most significant a _m consist of digits signal sequence of the signal (separated signal sequence X _m) of the signal sequence Z for An encoding method comprising: The encoding method according to claim 8, comprising:
A combination of the initial phase P _vm and the interval T _vm of the M _v group (where v is an integer of 1 or more and V or less and V is an integer of 2 or more) is recorded in advance in V types.
Using the input signal sequence Z, a combination of M _v sets of initial phases P _vm and intervals T _vm estimated to have the best coding efficiency among the V types is obtained, and these are determined as the initial values of the M sets. coding method also has selection step of a combination of the phase P _m and intervals T _m. The encoding method according to claim 8 or 9, comprising:
In the encoding method, the signal extraction step outputs the signal sequence Z when the encoding efficiency is better when the input signal sequence Z is not separated. The encoding method according to claim 8, comprising:
Obtaining the maximum digit in the signal sequence Z and the position U _{j of the} signal having the maximum digit (where j is an integer from 1 to J and J is the number of signals having the maximum digit);
For each predetermined t, the position U _j is sequentially divided to obtain a remainder p, and among a plurality of predetermined initial phase / interval combinations {P, T}, those that match the combination {p, t} Delete it,
When the combination {P, T} of the initial phase and the interval remains, the remaining combination {P, T} of the initial phase and the interval is set as a combination of the M sets of initial phases P _m and the interval T _m. With steps,
An encoding method, wherein if the combination of the initial phase and the interval {P, T} does not remain, the signal extraction step outputs a signal sequence Z. An initial phase P (where P is an integer greater than or equal to 0) and an interval T (where T is an integer greater than or equal to 2) and the (P + n × T) th signal from the input signal sequence Z (where n is greater than or equal to 0) And a signal extraction step of collecting an integer) in which P + n × T is smaller than the number of signals in the signal sequence Z;
The maximum digit A in the (P + n × T) th signal of the signal sequence Z (where the digit is a bit representing the absolute value of the amplitude of the signal) is obtained, and the (P + n × T) th digit of the signal sequence Z is obtained. And a separated signal sequence generation step of generating a signal sequence (separated signal sequence X) composed of digits less than or equal to the maximum digit A of the signal. The initial phase P _m (where P is an integer greater than or equal to 0, m is an integer from 1 to M) and the interval T _m (where T is an integer greater than or equal to 2) of M pairs (where M is an integer greater than or equal to 1) For each combination, the (P _m + n × T _m ) th signal from the input signal sequence Z (where n is 0 or more and P _m + n × T _m is smaller than the number of signals in the signal sequence Z). Signal extraction step to collect an integer),
All the (P _m + n × T _m ) th signals are deleted from the signal sequence Z, and the maximum digit A (where the digit is a bit representing the absolute value of the amplitude of the signal) is obtained. And a residual signal sequence generation step of generating a signal sequence (residual signal sequence Y) composed of digits less than or equal to the maximum digit A of the remaining signal. Residual signal sequence Y, M phases (where M is an integer greater than or equal to 1), initial phase P _m (where P is an integer greater than or equal to 0, m is an integer between 1 and M), and interval T _m (where T is 2 is a decoding method for decoding a signal sequence Z by inputting a maximum digit A _m (where a digit is a bit representing the absolute value of the amplitude of a signal) and a separated signal sequence X _m. ,
The separated signal sequence _{X m,} the most significant _{A m} by using the signal sequence _{Z (P m + n × T} m) th signal (where, n is an 0 or _{more, P m} + n × _T m is the signal sequence A restoration step to restore to an integer smaller than the number of signals of Z;
An insertion step of inserting the restored signal into the residual signal sequence Y so as to be the (P _m + n × T _m ) th signal of the signal sequence Z;
A decoding method comprising: Initial phase P (where P is an integer greater than or equal to 0), interval T (where T is an integer greater than or equal to 2), maximum digit A (where digit is a bit representing the absolute value of the amplitude of the signal) and separated signal A decoding method with a column X as input,
Each signal of the separated signal sequence X is the (P + n × T) th signal of the signal sequence Z to be decoded using the maximum digit A (where n is 0 or more and P + n × T is the signal sequence Z signal) A decoding step having a restoration step of restoring to an integer smaller than a number). Residual signal sequence Y and maximum digit A (where the digit is a bit representing the absolute value of the amplitude of the signal) and M phases (where M is an integer equal to or greater than 1) initial phase P _m (where P is 0) A decoding method for decoding a signal sequence Z by inputting the above integer, m is an integer from 1 to M), an interval T _m (where T is an integer of 2 or more) and a separated signal sequence X _m ,
The remaining signal sequence Y is the (P _m + n × T _m ) th signal of the signal sequence Z using the maximum digit A (where n is 0 or more and P _m + n × T _m is equal to the signal sequence Z). A restoration step for restoring to a signal other than an integer smaller than the number of signals,
An insertion step of inserting a separated signal sequence X _m into the restored signal so as to be the (P _m + n × T _m ) th signal of the signal sequence Z;
A decoding method comprising:   An encoding program for causing a computer to execute each step of the encoding method according to claim 8.   A decoding program for causing a computer to execute each step of the decoding method according to claim 14.   A computer-readable recording medium on which the encoding program according to claim 17 is recorded. A computer-readable recording medium on which the decryption program according to claim 18 is recorded.

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