JP2003186499A - Encoding device and decoding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an encoding device and a decoding device for realizing wideband encoding and decoding for a digital sound signal. <P>SOLUTION: This encoding device 100 is provided with: a converting part 120 for segmenting an input sound signal in each fixed time to convert the input sound signal into a frequency spectrum and generating a window for a short block; a sharing judging part 137 for comparing windows with each other, judging that spectrum data in a high-pass part of one window are shared by the other window if spectrums of each of the windows are similar within a range satisfying a prescribed judgment standard, and replacing the spectrum data in the high-pass part of the other window with '0'; a first quantizing part 131 for quantizing the spectrum data of each of the windows after replacement processing; a first encoding part 132 for encoding quantization results of the first quantizing part 131; and a stream outputting part 140 for outputting the encoded data by the first encoding part 132. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high quality audio encoding and decoding technique for digital audio data.

[0002]

2. Description of the Related Art Currently, various audio compression methods for compressing and encoding audio data have been developed. MPEG-2 Ad
advanced Audio Coding (hereinafter AA
(Abbreviated as C) is one of the methods. For details of AAC, refer to "ISO / IEC 13818-7 (MPEG-2).
Advanced Audio Coding, AA
C) ”.

First, the conventional encoding and decoding procedure is shown in FIG.
This will be described using 7. FIG. 17 shows a conventional MPEG-2.
Encoding device 300 and decoding device 40 based on the AAC method
It is a block diagram which shows the structure of 0. Encoding device 300
Is an apparatus for compressing and encoding an input acoustic signal based on the MPEG-2 AAC encoding method, and is an acoustic signal input unit 310, a conversion unit 320, a quantization unit 331, an encoding unit 332, and a stream output unit. 340.

The acoustic signal input section 310 includes, for example, 44.
Digital audio data sampled at a sampling frequency of 1 kHz is cut out every 1024 continuous samples. The coding unit of 1024 samples is called "frame".

The conversion unit 320 uses the MD of the sample data on the time axis cut out by the acoustic signal input unit 310.
CT (Modified Discrete Cosi)
(neTransform) to convert the spectrum data on the frequency axis. In addition, 1 converted at this time
The spectral data of 024 samples is classified into a plurality of groups. Each of the groups is set so that each of the plurality of groups includes one or more samples of spectral data. Also, each of these groups simulates a critical band in human hearing. Each of the groups is called a “scale factor band”.

The quantizer 331 quantizes the spectrum data obtained from the converter 320 with a predetermined number of bits. M
PEG-2 AAC quantizes the spectral data within the scale factor band using one normalization factor for each scale factor band. This normalization coefficient is called "scale factor". In addition, the result of quantizing each spectrum data with each scale factor is referred to as a “quantized value”. The encoding unit 332 Huffman-encodes the data quantized by the quantization unit 331, that is, each scale factor and the spectrum data quantized using the scale factor into a stream format. At this time, the encoding unit 332 obtains the difference between the scale factors of the scale factor bands adjacent to each other in the front and rear in one frame, and performs the Huffman encoding on the difference and the scale factor of the leading scale factor band.

The stream output unit 340 includes a coding unit 33.
The encoded signal obtained from 2 is converted into an MPEG-2 AAC bitstream and output. Encoding device 300
The bit stream output from is transmitted to the decoding device 400 via a transmission medium, or recorded on a recording medium such as an optical disk such as a CD or a DVD, a semiconductor, a hard disk, or the like.

The decoding device 400 is a device for decoding the bitstream coded by the coding device 300, and comprises a stream input section 410, a decoding section 421,
The inverse quantization unit 422, the inverse conversion unit 430, and the acoustic signal output unit 440 are included.

The stream input section 410 is used by the encoding device 3.
The bit stream coded by "00" is input through the transmission medium or the recording medium after being reproduced, and the coded signal is extracted from the input bit stream. The decoding unit 421 decodes the extracted coded signal from the stream format into quantized data.

The dequantization section 422 dequantizes the quantized data decoded by the decoding section 421. MPEG-2
AAC decodes Huffman-encoded data. The inverse transform unit 430 transforms the spectrum data on the frequency axis obtained by the inverse quantization unit 422 into sample data on the time axis. In MPEG-2 AAC, IMDC
T (Inverse Modified Discre
te CosineTransform). The acoustic signal output unit 440 sequentially combines the sample data on the time axis obtained by the inverse conversion unit 430, and outputs it as digital acoustic data.

In MPEG-2 AAC, the conversion length of MDCT can be changed according to the input acoustic signal. A block having a conversion length of 2048 samples is called a LONG block, a block having a conversion length of 256 samples is called a SHORT block, and these are collectively called a block size.
In the SHORT block, assuming that the sampling frequency of the input digital audio data is 44.1 kHz, 12 consecutive digital audio data are generated in the encoding device.
For every 8 samples, a total of 256 samples of acoustic data are cut out by overlapping 64 samples before and after that. The cut out digital acoustic data is subjected to MDCT conversion, and spectral data of 128 samples, which is half of the conversion result, is subjected to quantization and encoding. In the SHORT block, eight continuous windows each composed of the spectral data of 128 samples are put together into one frame of 1024 samples, and subsequent processing such as quantization and coding is performed using this frame as one processing unit. .

As described above, the SHORT block of 128 samples per window has the same 22.05 kHz as the LONG block of 1024 samples per block.
Since the reproduction band of z is represented by a small number of samples, it is disadvantageous in terms of sound quality as compared with the LONG block, but has an advantage that it has high followability to an acoustic signal of a quick cycle. That is, in the case of the LONG block, since the cutout cycle is long, when the cutout acoustic signal includes an attack (a spike wave with a large amplitude), 1024
There is a problem that the frequency component of the attack affects the entire spectrum of the sample. On the other hand, S
In the HORT block, even if an attack is included, its influence is suppressed within one window, so that there is an advantage that the original sound can be reproduced more faithfully without being affected by the spectra of other windows.

[0013] As one measure of how much the sound quality of the audio data encoded by the encoding device 300 and transmitted to the decoding device 400 is maintained,
There is a reproduction band after encoding. For example, when the sampling frequency of the input signal is 44.1 kHz, the reproduction band is 22.0.
It becomes 5 kHz. This 22.05 kHz, or 22.
High-quality sound signal transmission can be achieved by encoding a broadband acoustic signal close to 05 kHz without deterioration and transmitting all the encoded data. However, the width of the reproduction band affects the number of spectrum data, and the number of spectrum data affects the transmission data amount. For example, the sampling frequency of the input signal is 44.1.
2 kHz spectrum data of 1024 samples at kHz
Corresponding to 2.05kHz data, 22.05kHz
In order to secure the reproduction band of, it is necessary to transmit all the spectrum data of 1024 samples. For this purpose, it is necessary to efficiently encode the acoustic signal and keep the data amount within the transfer rate range of the transmission path.

However, considering a transmission line of a low transfer rate such as a mobile phone, it is not realistic to actually transmit all the spectrum data of 1024 samples because the data amount is too large. In other words, if you try to transfer all spectrum data in this playback band with a data amount that matches the transfer rate, the amount of information that can be assigned to each frequency band will be small, and as a result, the effect of quantization noise will increase, Audio quality is deteriorated due to encoding.

Therefore, not only in the MPEG-2 AAC but also in many audio signal coding systems, auditory weighting is applied to the spectrum data and low priority data is not transmitted, so that efficient audio signal transmission is achieved. Has been realized. According to this, in the reproduction band, in order to improve the coding accuracy of the low-frequency part having a high auditory priority, a sufficient amount of data is allocated to the coding information of the low-frequency part and The part has a high probability of being excluded from transmission.

[0016]

[Problems to be Solved by the Invention] However, MPE
Despite such ingenuity in the G-2 AAC system, further improvement in quality and improvement in compression efficiency are demanded for audio signal encoding. That is, there is an increasing demand for transmitting high-frequency acoustic signals even at low transfer rates.

An object of the present invention is to provide an encoding device and a decoding device which can realize high-quality encoding of an audio signal and its decoding without significantly increasing the amount of information after encoding. .

[0018]

In view of the above-mentioned problems, an encoding device of the present invention is an encoding device for encoding an input acoustic signal, and the input acoustic signal is cut out at regular intervals to obtain a frequency. A conversion unit that generates a plurality of sets each composed of a set of spectrum data by converting into a spectrum and the sets obtained by the conversion unit are compared with each other, and the spectra of the sets are predetermined. In the case of similarity in a range satisfying the criterion of (1), sharing determination means for determining that the high band spectral data of one set is shared by the other set, and the other set determined to share the high band spectral data Therefore, the replacement means for replacing the high band spectrum data of the set with a predetermined value, and the replacement processing by the replacement means, the spectrum data of each set is quantized. A first quantization means for said first
It is characterized by comprising first encoding means for encoding the quantization result by the quantization means, and output means for outputting the data encoded by the first encoding means.

In response to this, the decoding apparatus of the present invention is
First decoding means for decoding the data encoded by the first encoding means in the input encoded data, and the result of decoding by the first decoding means are dequantized to obtain the spectrum data of each set. The first dequantization means for outputting and the dequantization result of the first dequantization means are monitored, and the value of the high frequency band spectrum data output by the first dequantization means becomes a predetermined value. If it is determined that the pair is the other pair, the high band part of the one pair is determined from the dequantization result of the first dequantization means based on the determination of the determination means. A second dequantization means for copying the spectrum data represented, outputting the copied spectrum data in association with the other set, and high-band part spectrum data output by the first dequantization means, Second
After replacing the values of the high frequency band spectrum data of the set associated by the dequantization means with the values of the high frequency band spectrum data output by the second dequantization means,
An acoustic signal output unit that performs inverse conversion and outputs as an acoustic signal on a time axis is provided.

Further, in the encoding apparatus of the present invention, the sharing determination means further adds to the high-frequency part of one of the pairs when the spectra of the pairs are similar to each other within a range satisfying a predetermined determination criterion. It is determined that the spectrum data of the low frequency band is shared by the other pair, and the replacing unit further lowers the other frequency band of the other pair determined to share the spectrum data in addition to the high frequency band of the pair input. It is characterized in that the spectrum data of the region is replaced with a predetermined value.

In response to this, the decoding device of the present invention is
First decoding means for decoding the data encoded by the first encoding means in the input encoded data, and the result of decoding by the first decoding means are dequantized to obtain the spectrum data of each set. When the first dequantization means for outputting and the dequantization result of the first dequantization means are monitored, and the values of all spectrum data output by the first dequantization means are predetermined values. , The determination unit that determines that the set is the other set, and, based on the determination by the determination unit, copies all spectrum data of the one set from the dequantization result of the first dequantization unit. , A second dequantization means for outputting the copied spectrum data in association with the other set, and spectrum data output by the first dequantization means, the second dequantization means being associated with each other. Has been After replacing all the spectrum data values of the above with the spectrum data values output by the second dequantization means, inverse conversion is performed, and the sound signal output means outputs as a sound signal on the time axis. Characterize.

Further, the coding apparatus of the present invention is a coding apparatus for coding an input acoustic signal, and converting means for cutting out the input acoustic signal at regular time intervals and converting it into a frequency spectrum, and the conversion means. First quantizing means for quantizing the spectrum data obtained by the means;
Of the spectral data input to the quantizing means, the first
In the quantizing means, second quantizing means for requantizing the spectrum data adjacent to the peak of the spectrum whose quantization result is continuously a predetermined value using a predetermined normalization coefficient; and the first quantum. First encoding means for encoding the quantization result of the encoding means, second encoding means for encoding the quantization result of the second quantization means, and data encoded by the first encoding means And output means for outputting the data encoded by the second encoding means.

In response to this, the decoding device of the present invention is
A decoding device for inputting encoded data encoded by the encoding device and decoding the input encoded data, wherein data encoded from the input encoded data by the second encoding means And a first decoding means for decoding the data encoded by the first encoding means in the input encoded data, and a decoding result of the first decoding means. First dequantization means for dequantizing and outputting the spectrum data of each band, second decoding means for decoding the data coded by the second coding means, and second decoding means. Dequantize the decoding result of using a predetermined normalization coefficient,
Second dequantizing means for reconstructing continuous spectrum data whose quantization result by the first quantizing means is a predetermined value because the spectrum data is adjacent to the peak spectral data in each band, and the first dequantizing means 1 for each band of the spectral data output by the means
The values of a plurality of spectrum data which are adjacent to the front and rear of the spectrum data and which continuously have a predetermined value are replaced with the values of the spectrum data restored by the second dequantization means, and then inversely transformed. And an audio signal output means for outputting as an audio signal on the time axis.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) Hereinafter, encoding apparatus 100 and decoding apparatus 200 according to the present embodiment will be described in detail. FIG. 1 shows an encoding device 1 of the present invention.
00 and a decoding device 200. FIG.

<Encoder 100> Encoder 100
Is an audio coded bitstream that reduces the data amount of an audio signal that has been conventionally transmitted and transmits the same, and if the transmitted data amount is the same, the decoding device 200 can restore an audio signal of higher sound quality than before. Is output. Specifically, in the case of the SHORT block, eight blocks (= windows) of 128 sample units are collectively transmitted, but if the spectral data in the high frequency band is similar or similar in two or more windows, the high frequency band will be transmitted. The amount of data is reduced by sharing the quantized data of each part. The encoding device 100 includes an acoustic signal input unit 110, a conversion unit 120, and a first
Quantization unit 131, first encoding unit 132, second encoding unit 134, sharing determination unit 137, and stream output unit 1
It consists of 40.

The acoustic signal input section 110 has a frequency of 44.1.
MP sampled at a sampling frequency of kHz
Digital acoustic data, which is an input signal similar to that of EG-2 AAC, is divided into 256 samples by overlapping 64 samples before and after the same in a cycle of about 2.9 msec (every 128 samples).

The conversion section 120 converts the sample data on the time axis cut out by the acoustic signal input section 110 into spectrum data on the frequency axis, as in the conventional case. M
In PEG-2 AAC, MDCT is used to convert the time axis data of 256 samples into the spectral data of 256 blocks of the SHORT block. But MDC
In T, since the spectrum data is bilaterally symmetric, only one of the 128 samples is to be encoded. Below,
A unit of 128 samples in the SHORT block is called a "window", and one frame consists of 8 windows and 1024 samples.

The conversion unit 120 further classifies the converted spectrum data of one window into a plurality of scale factor bands each containing one sample or more (practically a multiple of 4) of spectrum data. MPEG-
In 2 AAC, the number of scale factor bands included in one frame is determined according to the block size and the sampling frequency, and the number of samples (spectral data) included in each scale factor band is also determined according to the frequency. ing. The scale factor band is finely divided into a small number of samples in the low frequency part, and is divided into a large number so as to include a large number of samples in the high frequency part. In the SHORT block, when the sampling frequency is 44.1 kHz, the number of scale factor bands included in one window is 14. 128 of each such window
When the sampling frequency of the input sound source is 44.1 kHz, the spectral data of each sample is 22.0.
It represents a reproduction band of 5 kHz.

FIG. 2 is a diagram showing a conversion process of an acoustic signal processed in the coding apparatus 100 shown in FIG.
FIG. 2A is a waveform diagram showing sample data on the time axis cut out into each SHORT block by the acoustic signal input unit 110 shown in FIG. 1. 2 (b) is shown in FIG.
4 is a waveform diagram showing spectrum data of one frame of SHORT blocks after being subjected to MDCT conversion by the conversion unit 120 shown in FIG. In the spectrum data shown in FIG. 2B, the vertical axis represents the spectrum value and the horizontal axis represents the frequency. 2 (a) and 2 (b),
Although the sample data and the spectrum data are shown as analog waveforms, both are actually digital signals. The same applies to the following waveform diagrams. Note that FIG.
In (b), a waveform consisting of only positive values is shown for the sake of simplicity. However, in reality, the spectrum data obtained by MDCT conversion may have negative values.

A digital audio signal as shown in FIG. 2A is input to the audio signal input section 110. The acoustic signal input unit 110 cuts out 256 samples by overlapping the 64 samples before and after that at the timing of cutting out every 128 samples from this input signal, and outputs it to the conversion unit 120. The conversion unit 120 MDCTs the data of 256 samples in total, but the spectrum obtained by MDCT has a symmetrical waveform, and thus generates the spectrum data corresponding to half the 128 samples. Figure 2
(B) shows the SHORT block composed of eight windows generated in this way, one frame of spectral data, and each window has 128 points of spectral data generated by the conversion unit 120 about every 2.9 msec. Consists of. That is, each window has 128
The amount (magnitude) of the frequency component contained in the acoustic signal represented by the voltage value of the sample is represented by the spectrum data of 128 points corresponding to the number of samples.

The sharing determination unit 137 determines whether or not the quantized data of the high frequency band is shared with other windows for the eight windows of the spectrum data output from the conversion unit 120, and the high frequency band quantization is performed. When the digitized data is shared with another window, the value of the high frequency band spectrum data of the window is replaced with "0". For example, as a specific determination method, an energy difference between spectra is obtained with respect to a window immediately before which high frequency band data is not shared, and when the energy difference is less than a threshold value, it is determined to be shared. The sharing determination unit 137 generates a flag indicating whether or not to share, corresponding to each window, and includes the generated flag, and indicates which window shares the high frequency region quantized data of the immediately previous window. Output information.

The first quantizing unit 131 has a sharing determining unit 13
Input the spectrum data to be output from 7 and for each scale factor band of the input spectrum data,
Determine the scale factor for each. Furthermore, the spectrum in the scale factor band is quantized using the determined scale factor, and the quantized value and the scale factor which are the quantized result are quantized by the first encoding unit 13
Output to 2. Specifically, the first quantizer 131
Calculate the scale factor of each scale factor band so that the number of bits after encoding of each frame falls within the range of the transfer rate of the transmission path, normalize each spectrum in the scale factor band using the scale factor, Quantize.

The first encoder 132 encodes the quantized value of the spectrum data of 1024 samples quantized by the first quantizer 131, the scale factor used for the quantization, and the like as the first code. It is Huffman-encoded as a converted signal and converted into a predetermined stream format.
Regarding the scale factor, the respective differences are sequentially obtained, and the leading scale factor and the difference are Huffman-encoded.

The second encoding unit 134 receives sharing information indicating whether or not each window shares the high frequency band quantized value of the immediately preceding window from the sharing determination unit 137, and the sharing information is transmitted to a predetermined stream. Huffman-encoded into a format for and output as a second encoded signal.

The stream output section 140 adds header information and other necessary sub-information to the first encoded signal output from the first encoding section 132 to add MPEG-2.
The second coded signal converted into the AAC coded bit stream and output from the second coding unit 134 is ignored by the conventional decoding device in the bit stream or its operation is defined. Store in an area that has not been set.

Specifically, the stream output section 140 is
The encoded signal output from the second encoding unit 134 is M
Fill Element and Data Stream in PEG-2 AAC encoded bit stream
Stored in Element.

The bit stream output from the coding device 100 is transmitted to the decoding device 200 via a transmission medium such as a mobile telephone communication network, a communication network such as the Internet, a broadcast wave of cable television and digital television. It is recorded on a recording medium such as an optical disk such as a CD or a DVD, a semiconductor, a hard disk, or the like.

Furthermore, in actual MPEG-2 AAC encoding processing, Gain Control and TNS (T
Emporial Noise Shaping), psychoacoustic model, M / S Stereo, Intensit
There are cases where tools such as y Stereo and Prediction are used, block size switching, and bit reservoirs are used.

<Decoding Device 200> Decoding Device 200
Is a decoding device that restores wideband acoustic data added with a high frequency part from an input coded bitstream based on the shared information, and is a stream input part 21.
0, the first decoding unit 221, the first dequantization unit 222,
The second decoding unit 223, the second dequantization unit 224, the dequantized data combination unit 225, the detransformation unit 230, and the acoustic signal output unit 240 are included.

The stream input unit 210 passes through a portable telephone communication network, a communication line network such as the Internet, a transmission path such as a cable television and a transmission medium such as broadcast radio waves, or reproduces from a recording medium to reproduce data from the encoding device 100. The first encoded signal stored in the area to be decoded by the conventional decoding apparatus 400 and the operation performed on the information that the conventional decoding apparatus 400 ignores or inputs the bit stream generated in And the second coded signal (shared information) stored in the area in which is not specified, and the first decoding section 221 and the second decoding section 2 respectively.
23 and 23.

The first decoding unit 221 inputs the first coded signal output from the stream input unit 210, and decodes the Huffman-coded data from the stream format into quantized data. Second decoding unit 223
Inputs the second encoded signal output from the stream input unit 210, decodes the input second encoded signal, and outputs shared information. In the second dequantization unit 224, the second dequantization unit 224
Referring to the shared information output from the decryption unit 223 of
The spectrum data output from the first inverse quantization unit 222 is copied and output for the portion shared by the other windows.

The dequantized data synthesizing section 225 synthesizes the spectrum data output from the first dequantization section 222 and the spectrum data output from the second dequantization section 224. Specifically, for the spectrum data input from the first dequantization unit 222, if there is spectrum data input by designating a frequency from the second dequantization unit 224, the first dequantization unit The spectrum data value of the frequency output from the quantization unit 222 is replaced with the spectrum data value output from the second dequantization unit 224. Also, the second
If there is high frequency band spectrum data input from the dequantization unit 224 of the window, the high frequency band spectrum data output from the first dequantization unit 222 of the window is converted into the second high frequency band spectrum data. The spectral value input from the inverse quantization unit 224 is replaced.

The inverse transform unit 230 uses the MPEG-2 AAC.
Accordingly, the spectrum data on the frequency axis output from the inverse quantized data synthesis unit 225 is converted into sample data of 1024 samples on the time axis using IMDCT. The acoustic signal output unit 240 sequentially combines the sample data on the time axis obtained by the inverse conversion unit 230, and outputs it as digital acoustic data.

In this way, by sharing some of the high band quantized data of the eight windows, the shared high band information can be minimized while minimizing the deterioration of the reproducibility of the spectral data. There is an effect that the amount of data transmission can be reduced by that amount.

FIG. 3 is a diagram showing an example of sharing of high frequency band data by the sharing determination unit 137 shown in FIG. Figure 3
2B shows the spectrum data of the SHORT block for one frame obtained by MDCT conversion, as in FIG. 2B. In FIG. 3, for each window, the left side separated by a broken line is, for example, 0 kHz to 11.025 kHz.
The low-frequency part that represents the playback band up to Hz, and the right side is 11.0
The high frequency band is the reproduction band from 25 kHz to 22.05 kHz.

Further, the spectra of two adjacent windows are likely to have waveforms similar to each other as shown in FIG. 3 because the cycle for cutting out the windows is short. In such a case, the sharing determination unit 137 determines to share the high frequency region quantized data between windows having waveforms similar to each other. For example, when the spectra of the first window and the second window have high similarity and the spectra of the third window to the eighth window have high similarities to each other, the sharing determination unit 137 causes the sharing determination unit 137 to determine the first window and the second window. And the high band quantized data are shared, and the third window and the fourth and subsequent windows share the high band quantized data. In this case, the spectrum data in the range indicated by the arrow in FIG. 3 is transmitted (that is, quantization and coding).
The spectrum data in the high frequency band of the second window and the fourth to eighth windows other than that are not subject to transmission (that is, quantization and encoding), and are not “0” by the sharing determination unit 137. Will be replaced with

FIG. 4 shows the stream output unit 1 shown in FIG.
It is a figure which shows the data structure of the bit stream which stores the 2nd encoding signal (shared information) by 40. Figure 4
(A) is a figure which shows the data structure inside each area | region when the 2nd coded signal is stored in a bit stream.
FIG. 4B is a diagram showing an example of a partial data structure of an audio coded bit stream conforming to MPEG-2 AAC. FIG. 4C is a diagram showing another example of a partial data structure of an audio coded bitstream conforming to MPEG-2 AAC. The shaded portion in FIG. 4B is, for example, an area (FillElemen) filled with “0” to match the data length of the bitstream.
t). In addition, the hatched portion in FIG. 4C indicates, for example, Data Stream Element.
The area (DSE) is an area in which only the physical structure such as the bit length is defined by the MPEG-2 AAC standard for future expansion. The above-mentioned shared information is encoded by the second encoding unit 134, and then has identification information as shown in FIG.
It is stored in the area such as.

When the second coded signal is stored in the Fill Element, the conventional decoding apparatus 400 does not recognize the coded signal to be decoded and ignores it. DS
When the second coded signal is stored in E, even if the second coded signal is read by the conventional decoding apparatus 400, the decoding apparatus 400 for the second coded signal read in the DSE Is not specified, the decoding apparatus 400 does not perform any processing corresponding to this.
Therefore, by storing the second coded signal in such an area, even if the coded bit stream by the coding apparatus 100 of the present invention is input to the conventional decoding apparatus 400, Since the coded signal is not decoded as an acoustic coded signal, it is possible to prevent the occurrence of noise or the like due to the inability to correctly decode the second coded signal. Thereby, even in the conventional decoding device 400, according to only the first coded signal,
There is an effect that the audio signal can be reproduced as usual without any trouble.

When the second coded signal is stored in such a Fill Element, Fill Element is used.
The header information of FIG. 4A is provided in the nt from the beginning. This header information includes the Fill Element
FillElement identifier and F indicating that
Bit number data indicating the bit length of the entire ill Element is included. Even when the second encoded signal is stored in the DSE, the header information shown in FIG. 4A is provided as in the case of the Fill Element,
The following data includes a DSE identifier indicating that it is a DSE and bit number data indicating the bit length of the entire DSE. The stream output unit 140 stores the second encoded signal including the identification information and the shared information, following the header information.

The identification information is information indicating whether or not the coded information stored below is coded by the coding apparatus 100 of the present invention. For example, if the identification information is "0
001 ”, the following encoding information is obtained by the encoding device 10
This indicates that the shared information is coded by 0. Further, for example, if the identification information is “1000”,
It is indicated that the following coded information is not coded by the coding apparatus 100. In the above example, if the identification information is “0001”, the decryption device 200 of the present invention decrypts the following shared information by the second decryption unit 223 and converts it into the shared information obtained as a result of the decryption. The high frequency band spectrum data of each window is restored based on this, but if the identification information is “1000”, the following encoded data is ignored. Like this Fill Element and DSE,
Even if the encoded data is stored inside, when the second encoded signal is stored in the areas which are not recognized as the acoustic encoded signals by the conventional decoding device 400, these areas are based on other methods. Encoding information may also be stored. In such a case, by including identification information in the second coded signal, other coded information and the second code of the present invention can be obtained.
This has the effect that it can be clearly distinguished from the coded signal of 1 and the confusion thereof can be easily prevented.

Further, by using this identification information, in addition to the above-mentioned examples, the above-mentioned shared information is combined with other information (for example, auxiliary information) based on the following embodiments of the present invention. When it is stored in the second encoded signal, the effect can be clearly indicated to the decoding device 200. Note that this identification information does not necessarily have to be added to the beginning of the second encoded signal, and may be inserted at the end or part of the encoded shared information.

FIG. 5 shows the stream output unit 1 shown in FIG.
It is a figure which shows the other data structure of the bit stream in which the 2nd encoding signal (shared information) is stored by 40.
In this case, the audio coded bit stream is MP
It does not have to comply with EG-2 AAC. Figure 5
(A) shows stream 1 in which only the first coded signal is continuously stored for each frame. Figure 5
(B) shows stream 2 in which only the second encoded signal in which shared information is encoded is continuously stored for each frame corresponding to stream 1. Figure 5 (b)
In the stream 2 shown in FIG. 4, shared information to which header information and identification information are added as shown in FIG. In this way, the stream output unit 140 may store the first encoded signal and the second encoded signal in completely different streams 1 and 2, respectively. For example, the stream 1 and the stream 2 may be bit streams transmitted on different channels.

As described above, by transmitting the first coded signal and the second coded signal by completely different bit streams, the low-frequency part representing the basic information of the input acoustic signal is transmitted or accumulated in advance. In addition, there is an effect that the information regarding the high frequency region can be added later, if necessary.

When the encoded bit stream incorporating the second encoded signal is output only to the decoding device 200 of the present invention, it is predetermined between the encoding device 100 and the decoding device 200. The second encoded signal may be incorporated at a predetermined position in the header information other than the above, the second encoded signal may be incorporated at a predetermined position in the first encoded signal, or both may be incorporated. Further, in order to store the second coded signal in the bit stream, it is not necessary to secure a continuous area in the header and the first coded signal. FIG. 5 (c)
FIG. 6 is a diagram showing a data structure of a bitstream when the second coded signal is inserted in the header information of the bitstream and the first coded signal in a scattered manner. That is, as shown in FIG. 5C, the second coded signal may be discontinuously incorporated in the header information and the first coded signal. Also in this case, the shared information to which the header information and the identification information are added is sequentially stored as shown in FIG.

Coding apparatus 100 configured as described above
The operation of the decoding apparatus 200 will be described below with reference to the flowcharts of FIGS. 6, 7, and 10 and the waveform chart of FIG. 6 is a block diagram of the first quantizer 13 shown in FIG.
It is a flow chart which shows operation in scale factor decision processing of No. 1. The first quantizer 131 first
As an initial value of the scale factor, a scale factor common to each scale factor band is determined (S9
1) Using the scale factor, all spectrum data output from the sharing determination unit 137 as acoustic data for one frame is quantized, and a difference before and after the obtained scale factor is calculated, and the difference and the beginning Huffman coding is performed on the scale factor and each quantized value (S92). Since the quantization and the encoding here are performed only for counting the number of bits, it is assumed that only the data is added and the information such as the header is not added in order to simplify the processing. Next, the first quantization unit 131 determines whether or not the number of bits of the Huffman-encoded data has exceeded a predetermined number of bits (S93). If the number of bits has exceeded, the initial value of the scale factor is lowered ( S10
1) Quantization and Huffman coding are performed again for the same spectrum data using the value of the scale factor (S92), and the number of bits of coded data for one frame after Huffman coding is set to a predetermined value. It is determined whether or not the number of bits is exceeded (S93), and this process is repeated until the number of bits is less than or equal to the predetermined number.

If the number of bits of encoded data does not exceed the predetermined number of bits, the first quantizer 131 repeats the following processing for each scale factor band to determine the scale factor of each scale factor band. (S94). First, each quantized value in the scale factor band is inversely quantized (S95), and the absolute value difference between each inverse quantized value and the corresponding original spectrum data is obtained and summed (S96). Further, it is judged whether or not the calculated sum of the differences is a value within the allowable range (S97), and if it is within the allowable range, the above process is repeated for the next scale factor band (S94 to S94).
98). On the other hand, if it exceeds the allowable range, the value of the scale factor is increased to quantize the spectrum data of the scale factor band (S10).
0), the quantized values are inversely quantized (S95), and the absolute value differences between the inverse quantized values and the corresponding spectrum data are summed (S96). Further, it is judged whether the total of the differences is within the allowable range (S97), and if it exceeds the allowable range,
The scale factor is sequentially increased until it is within the allowable range (S100), and the above processing (S95 to S97 and S1) is performed.
00) is repeated.

The first quantizer 131, for all scale factor bands, sums the difference between the absolute values of the dequantized quantized values in the scale factor bands and the original spectrum data within the allowable range. When such a scale factor is determined (S98), the spectrum data for one frame is quantized again using the determined scale factor, and the difference between each scale factor, the leading scale factor, and each quantized value are calculated. Huffman coding is performed, and it is determined whether the number of bits of the encoded data exceeds a predetermined number of bits (S99). If the number of bits of the encoded data exceeds the predetermined number of bits, the scale factor initial value is reduced until it becomes equal to or smaller than the predetermined number of bits (S101), and then the scale factor in each scale factor band is determined. Processing (S94 to S9
Repeat 8). If the number of bits of the encoded data does not exceed the predetermined number of bits (S99), the value of each scale factor at that time is determined as the scale factor of each scale factor band.

It should be noted that whether or not the sum of the differences between the absolute values of the dequantized quantized values in the scale factor band and the original spectrum data is within the allowable range is determined by data such as a psychoacoustic model. It is done based on.

Further, here, the initial value of the scale factor is set to a relatively large numerical value, and when the number of bits of the coded data after Huffman coding exceeds a predetermined number of bits, the scale factor of the scale factor is sequentially changed. The scale factor is determined by the method of lowering the initial value, but it is not always necessary to do so. For example, the initial value of the scale factor is set to a low value in advance, the initial value is gradually increased, and immediately before the total number of bits of encoded data exceeds a predetermined number of bits, The scale factor of each scale factor band may be determined by using the initial value of the scale factor set in the above.

Further, here, the scale factor of each scale factor band is determined so that the number of bits of the entire encoded data for one frame does not exceed a predetermined number of bits, but this need not always be the case. For example,
In each scale factor band, the scale factor may be determined so that each quantized value in the scale factor band does not exceed a predetermined number of bits.

FIG. 7 is a flow chart showing an example of the operation in the one-frame sharing determination processing of the sharing determination unit 137 shown in FIG. Here, it is assumed that the sharing determination unit 137 represents the determination result of each window in the frame with sharing information including, for example, eight flags corresponding to eight windows. Each of the flags indicates that the value "0" transmits the quantized data in the high frequency band, and the value "1" indicates that the quantized data in the high frequency band is shared with other windows.

The sharing determination unit 137 outputs all the spectrum data of the first window input from the conversion unit 120 to the first quantization unit 131, and after setting the flag which is the first bit of the sharing information to “0”. (S1) Then, the following determination process is repeated for each of the remaining second to eighth windows (S2 to S9).

That is, the energy difference of the spectrum between the window of interest and the window immediately before the window having the flag "0" is calculated (S3),
It is determined whether the energy difference is less than a predetermined threshold value (S4).

If the result of the determination is that the energy difference is less than the threshold value, it is determined that the current window and the immediately preceding window have similar spectra, and the spectrum is similar between the window of interest and the immediately preceding window. It is determined to share the high frequency spectrum data. In this case, the sharing determination unit 137 replaces the high frequency band spectrum of the window of interest with "0" (S5), and sets the bit corresponding to the window of interest in the shared information to "1" (S6). On the other hand, as a result of the determination, if the energy difference is equal to or more than the threshold value, it is determined that the high frequency band spectrum data is not shared between the target window and the immediately preceding window. In this case, the sharing determination unit 137 outputs all the spectrum data of the window of interest as it is to the first quantization unit 131 (S7), and sets the bit corresponding to the window of interest in the shared information to "0" (S8). .

For example, first, with the second window as the window of interest, the difference between the same frequencies is obtained for each of the spectral data of 128 samples of the second window and each of the spectral data of 128 samples of the first window. By summing the calculated differences, the energy difference between the spectra of the second window and the first window is calculated (S3), and it is determined whether or not the calculated energy difference is less than a predetermined threshold (S3). S
4).

Here, if the energy difference between the first window and the second window is less than the threshold value, the sharing determination unit 137 determines that the spectra of the second window and the first window are similar to each other. In the two windows, it is determined that the high frequency band data of the first window is shared. In response to this determination, the sharing determination unit 137 replaces all the high frequency band spectrum data of the second window with "0" (S5), and sets the flag of the second bit of the shared information to "1" (S6).

Since the determination process for the second window is finished (S9), the sharing determination unit 137 calculates the energy difference of the spectrum with the first window for the next third window (S2) (S3). ). Specifically, with respect to each of the spectral data of 128 samples of the third window and each of the spectral data of 128 samples of the first window, the difference between the same frequencies is obtained, and the obtained differences are summed, An energy difference between spectra of the second window and the first window is obtained. Furthermore, it is determined whether the calculated energy difference is less than a predetermined threshold value (S4).

As a result of the determination, if the energy difference is equal to or more than the threshold value, it is determined that the spectra of the third window and the first window are not similar to each other, and the high frequency band spectrum data of the first window is not shared in the third window. To determine. In response to this, the sharing determination unit 137
Without replacing the high frequency band spectrum data of the third window with "0", all the spectrum data is output as it is to the first quantization unit 131 (S7), and the flag of the third bit of the shared information is "0". To

Since the sharing determination unit 137 has finished the determination processing for the third window (S9), the high frequency spectrum data of the immediately preceding window for the next fourth window (S2) is " The energy difference from the output window is calculated without being set to "0". In this case, the immediately preceding window is the third window immediately before the consecutive windows that share the high frequency region quantized data with other windows. That is. Hereinafter, the sharing determination unit 1
37 repeats the sharing determination process up to the eighth window in the same manner as described above, and when the process for the eighth window ends, the process for one frame ends. As a result, the spectrum data of the one frame is output to the first quantization unit 131, and 8-bit shared information “01011111” for the frame is generated. In this case, the second window shares the high band quantized data with the immediately preceding first window, and the consecutive windows from the fourth to the eighth share the high band quantized data with the immediately preceding third window. Is shown. As another method of expressing the same shared information, when it is decided that the first window always transmits high-frequency quantized data, the first 1
The bits are omitted and the shared information is set to "10111111" and 7
It may be expressed in bits. The shared information does not have to be limited to such an expression. The sharing determination unit 137
The generated shared information is output to the second encoding unit 134,
After that, similar processing is performed for the next frame.

Here, the energy difference of the spectrum between the window that the sharing determination unit 137 is paying attention to and the immediately preceding window that is output without replacing the high-frequency part spectrum value with “0” is the whole area of each window. Although it was calculated for 128 samples, it is not always necessary to do this, and the energy difference between windows is calculated only for 64 samples in the high frequency band, and the high frequency band data is shared for the windows where the energy difference is less than the threshold value. Then, it may be determined.

Although the case where the high frequency band spectrum data is not replaced in the first window and all the spectrum data is always output as it is has been described here, it is not always necessary to do so. For example, the sharing determination unit 137
Is a window in which the energy difference of the spectrum is the smallest for any window in one frame. May be transmitted (quantized and encoded). In such a case, the high band spectrum data of the first window is not always transmitted.

In the present embodiment, it is determined whether or not a certain window shares the high frequency band with another window by determining the energy of the spectrum between the immediately preceding window that does not share the high frequency band data. The difference was calculated, and if the energy difference was less than the threshold value, it was determined to be shared, but
The criterion for determining whether or not the high frequency part quantized data is shared between the windows may not be the energy difference. For example, if the position (frequency) on the frequency axis of the spectrum data where the absolute value of the spectrum value is maximum in each window is found and the deviation of the position between the windows is less than the predetermined threshold value, The area quantized data may be shared. In addition, if the number and / or the position of the peaks of the spectrum are similar to the immediately preceding window that does not share the high frequency band data, it may be determined to be shared. Alternatively, these may be compared for each scale factor band, and scores may be evaluated according to the degree of similarity to make a comprehensive determination for one window. Also simply
With the previous window that does not share high band data,
If the positions of the spectrum data having the maximum absolute values are similar in the window, it may be determined to be shared. Further, the spectrum of each window may be multiplied by a predetermined function and compared, and whether or not to share may be determined based on the comparison result. In addition, when only the high frequency band data is shared, the high frequency band spectrum data may be shared between predetermined windows without comparing the similarity of spectra. For example, second, fourth,
It may be determined that the even-numbered window shares the high frequency band data with the odd-numbered window as in the sixth and eighth windows, and vice versa. In addition, a window in which the high frequency band data is not replaced with “0” may be defined in advance in any other combination. For example, the high frequency band data of one specific window may be shared by the other seven windows.

Furthermore, when there are a plurality of spectrum peaks in the high band part of each window, or in the entire window, the high band part between the windows where the frequency of each peak approximates within the range of the threshold value. The quantized data may be shared. Further, the high frequency part quantized data may be shared between windows in which the total frequency difference between windows of each peak falls within the threshold range.

Encoding device 100 generated as described above
Decoding device 2 to which the encoded bit stream from
In 00, when the first decoding unit 221 decodes the first coded signal according to the conventional procedure, spectrum data of 1024 samples is obtained. At this time, in the example of FIG. 7, all the spectrum values of the high frequency band spectrum data are “0” for the second and fourth to eighth windows. On the other hand, the second dequantization unit 224 has a memory for holding at least one window of high frequency band spectrum data output from the first dequantization unit 222, and the flag is For the window of "0", the spectrum data of the high frequency band, which is the output of the first dequantization unit 222, is held in the memory, and the held spectrum data is set to "1" thereafter. For each window that has been turned on, it is repeatedly copied and output until a window whose flag is "0" appears. The memory may be the one that is standardly provided for holding the spectrum data for one frame in the conventional decoding device 400 compliant with MPEG-2 AAC. There is no need to prepare. Further, if a memory is newly provided in the present invention, it is conceivable to add a storage area for storing pointers indicating the beginning of the window and the beginning of the high-frequency part that are the copy source of the spectrum data. Even in this case, if the processing procedure is set so as to search the memory based on the frequency of the target spectrum data, it is not necessary to add such a storage area. If it is desired to reduce the processing time during the search for the spectrum data, a memory may be provided as necessary. This memory is the same in the following spectral data copy processing. Hereinafter, the specific operation of the second dequantization unit 224 in this will be described using the flowchart of FIG.

FIG. 8 is a block diagram of the second inverse quantizer 2 shown in FIG.
It is a flowchart which shows the operation | movement in the copy process of 24 high frequency part spectrum data. Here, the second dequantization unit 224 is assumed to include at least a memory for storing the high frequency band spectrum data of 64 samples here, and for all windows in one frame (S71), If the flag is "0" (S72), the high frequency band spectrum data output from the first dequantization unit 222 is held in the memory (S73). If the flag is not "0" (S72), the memory The process of outputting the high frequency band spectrum data to the dequantized data synthesis unit 225 (S74) is repeated (S75).

That is, the second dequantization unit 224 checks one bit corresponding to the window of interest in the shared information decoded by the second decoding unit 223, and determines whether the flag of that bit is "0". It is checked whether or not (S72). As a result of the check, if the flag is “0”, the first dequantization unit 22
The high frequency band spectrum data of the window of interest dequantized by 2 is a spectrum that is not replaced with “0”. The second dequantization unit 224 holds this high frequency band spectrum data in the memory (S73) and updates the data if the data already exists in the memory. As a result of the examination (S72), if the flag is "1", all the high frequency band spectrum data output from the first dequantization unit 222 for the window of interest have a value of "0". . The second dequantization unit 224 reads the spectrum data in the memory for the window of interest and outputs the read spectrum data to the dequantized data synthesis unit 225 (S74). As a result, the high frequency band spectrum data of the window of interest is replaced with the spectrum value read from the memory by the second dequantization unit 224 in the dequantized data synthesis unit 225.

For example, first, focusing on the first window, it is assumed that the flag of the first bit of the shared information is "0". In this case, the second dequantization unit 224 writes the high frequency band spectrum data of the first window obtained by the first dequantization unit 222 in the memory and updates the data in the memory (S73). The second inverse quantizer 224 has a first
Since the spectrum data for the window is not output to the dequantized data synthesis unit 225, the first dequantized unit 22
The spectrum data output by 2 is output as it is to the inverse transform unit 230 via the inverse quantized data synthesis unit 225 as the spectrum data of the first window.

Next, focusing on the second window, it is assumed that the flag of the second bit of the shared information is "1". In this case, the second dequantization unit 224 selects the first dequantization unit from the memory.
The high frequency band spectrum data of the window is read and the read spectrum data is output to the inverse quantized data synthesizing section 225 as the high frequency band spectrum data of the second window (S74). From the first inverse quantizer 222, the second
The spectrum data of the window is output to the dequantized data synthesis unit 225, and the values of the high-frequency spectrum data of the second window are all “0”. This high-frequency part spectrum data is stored in the dequantized data synthesis unit 225.
In, the second dequantization unit 224 replaces the spectrum value of the first window read from the memory.

In this way, in the decoding device 200,
Based on the shared information from the encoding device 100, the high frequency band spectrum data of the window whose flag is “0” is copied to the window whose flag is “1”.

In the above description, the window sharing the high frequency band data is simply the high frequency band spectrum data that has not been replaced with "0" in the immediately preceding window, but is copied as necessary. The amplitude of the spectrum data may be adjusted. The adjustment of the amplitude is achieved by multiplying each spectrum by a predetermined coefficient and its value, for example, as “0.5”. This coefficient may be a fixed value, may be changed for each band, or may be changed according to the spectrum data output from the first inverse quantization unit 222.

Further, here, the decoding device 2 is used for adjusting the amplitude.
Although a predetermined coefficient is used in 00,
This coefficient may be calculated in the encoding apparatus 100 and added to the second encoded signal which is shared information. Alternatively, a scale factor value as a coefficient may be added to the second encoded signal, or a quantized value as a coefficient may be added to the second encoded signal. Further, the amplitude adjusting method is not limited to the above method and may be another method.

In the above embodiment, the high frequency spectrum data of the window having the flag of "0" is quantized and encoded by the conventional method and transmitted as the high frequency data to be shared. It doesn't have to be limited. For example, the flag is “0” as the high-frequency part data to be shared.
The high frequency band spectrum data of the window is not transmitted as in the conventional case, that is, the high frequency band spectrum data of all windows is replaced with "0".
Instead, auxiliary information is generated by simply expressing the acoustic signal in the high-frequency part of the window whose flag is "0" by the representative value of the acoustic signal, and the shared information and this auxiliary information are generated as second information. It may be encoded as an encoded signal. The auxiliary information is, for example, (1) such that the quantized value of the absolute maximum spectrum data (spectrum data having the maximum absolute value) within each scale factor band in the high frequency band is "1",
Scale factor Scale factor for each band,
(2) A scale factor common to all scale factor bands in the high frequency band is determined, and the scale factor is used to quantize the absolute maximum spectrum data for each scale factor band. (3) Each scale The position of the absolute maximum spectrum data in the factor band or the position of the absolute maximum spectrum data in the entire high band, (4) the sign indicating the sign of the spectrum at a predetermined position in the high band, and (5) the spectrum of the high band. This is represented by a copy method or the like when a similar low-frequency spectrum is copied to represent a high-frequency spectrum. Also, two or more of these may be combined. At this time, the decoding device 200 side restores the high frequency band spectrum data based on this auxiliary information.

The case where the scale factor (1) is used as auxiliary information will be described below. FIG. 9 is a spectrum waveform diagram showing a specific example of the auxiliary information (scale factor) generated for one window of the SHORT block by the sharing determination unit 137 shown in FIG.
In addition, in FIG. 9, the divisions shown on the frequency axis in the low frequency range and the divisions in the high frequency range indicated by broken lines in the frequency direction are
Although the division of the scale factor band is shown, it is simply shown for the sake of explanation, and its position is different from the actual position.

Of the spectrum data output from the conversion unit 120, the reproduction band 11.0 shown by the solid line waveform in FIG.
The low frequency band of 25 kHz or less is output to the first quantization unit 131 and quantized as usual. On the other hand, the high-frequency part up to the reproduction band 22.05 kHz exceeding the reproduction band 11.0525 kHz shown by the broken line waveform in FIG.
It is represented by the auxiliary information (scale factor) calculated by The calculation procedure of the auxiliary information (scale factor) of the sharing determination unit 137 will be described below with reference to the flowchart of FIG. 10 using the specific example of FIG.

FIG. 10 shows the sharing determination unit 137 shown in FIG.
5 is a flowchart showing an operation in auxiliary information (scale factor) calculation processing of FIG. The sharing determination unit 137
Playback band 12.0 Playback band 22.0 over 25 kHz
For all scale factor bands in the high frequency band up to 5 kHz, the optimum scale factor for setting the quantized value of the absolute maximum spectrum data in each scale factor band to "1" is calculated according to the following procedure (S11).

The sharing determination unit 137 determines the reproduction band 11.02.
The absolute maximum spectrum data (peak) in the first scale factor band in the high frequency band exceeding 5 kHz is specified (S12). In the specific example of FIG. 9, it is assumed that the position of the peak specified in the first scale factor band is and the peak value at that time is “256”.

The sharing determination unit 137 applies the peak value “256” and the scale factor value of the initial value to the formula for calculating the quantized value in the same manner as the procedure shown in the flowchart of FIG. 7, and obtains from the formula. The value of the scale factor sf at which the quantized value to be obtained is "1" is calculated (S1
3). For example, in this case, the value of the scale factor sf that makes the quantized value of the peak value “256” “1”, for example, sf = 24 is calculated.

When the scale factor value sf = 24 that sets the peak quantization value to "1" is obtained for the first scale factor band (S14), the sharing determination unit 137 determines that the next scale factor band is
The peak of the spectrum data is specified (S12), and for example, the position of the specified peak is and its value is "31.
2 ”, the value of the scale factor sf at which the quantized value of the peak value“ 312 ”becomes“ 1 ”, for example, sf
= 32 is calculated (S13).

Similarly, the sharing determination unit 137 determines, for the third scale factor band in the high frequency region,
The value of the scale factor sf that makes the quantized value of the peak value “288” “1”, for example, sf = 26, is calculated,
For the fourth scale factor band, the value of the scale factor sf that makes the quantized value of the peak value “203” “1”, for example, sf = 18 is calculated.

In this way, for all scale factor bands in the high frequency region, when the scale factors that make the quantized value of the peak value "1" are calculated (S1
4), the sharing determination unit 137 outputs the scale factor of each scale factor band obtained by the calculation to the second encoding unit 134 as auxiliary information of the high frequency band, and ends the process.

As described above, the auxiliary information (scale factor) is generated by the sharing determination unit 137. According to this auxiliary information (scale factor), the high frequency part is provided with one scale factor for each scale factor band. There is an effect that it can be expressed only. Furthermore, if each scale factor value is represented by a value from 0 to 255, each scale factor band (here, four) in the high frequency region can be represented by 8 bits. Further, if the difference of each scale factor is Huffman-encoded, the data amount may be further reduced. Therefore, this auxiliary information indicates only one scale factor for each scale factor band in the high frequency band, but the high frequency spectrum data is higher than that in the case of quantizing the high frequency band according to the conventional method. It can be seen that the amount of data is greatly reduced by not encoding the quantized value of the number.

Further, this scale factor shows a value almost proportional to the peak value (absolute value) in each scale factor band, and either generates spectral data having a constant value for the number of samples in the high frequency region, or It can be said that the spectrum data obtained by copying the spectrum data of the low frequency part and multiplying it by the scale factor roughly restores the spectrum data obtained based on the input acoustic signal. Alternatively, as another method, for each scale factor band, a quantized value “1” is obtained using the absolute maximum value of the spectrum data generated or copied in the band and the scale factor value corresponding to that band. The spectrum data can be more accurately restored by multiplying each spectrum data in the band by using the ratio of the inversely quantized value as a coefficient. (2) When the quantized value of the absolute maximum spectrum data for each scale factor band is used as the auxiliary information, the high frequency band spectrum data can be restored in the same manner as above. Further, the auxiliary information is a code indicating (3) the position of the absolute maximum spectrum data in each scale factor band or the position of the absolute maximum spectrum data in the entire high frequency region, or (4) the positive or negative of the spectrum at a predetermined position in the high frequency region. In this case, in the decoding device 200, a spectrum of a predetermined waveform is generated or a spectrum of the low frequency band is copied,
The spectrum is adjusted so that the waveform of the spectrum matches the condition represented by the auxiliary information of (3) or (4).
(5) When the copy method in the case of copying the spectrum of the low frequency band similar to the spectrum of the high frequency band to represent the spectrum of the high frequency band is used as the auxiliary information, the sharing determination unit 137,
Similar to the case of determining the similarity of spectra between windows, the scale factor band in the low frequency band that has a spectrum similar to the spectrum in each scale factor band in the high frequency region is specified, and the specified scale factor band is specified. The number is used as auxiliary information. In addition, there are two directions of copying the spectrum of the low-frequency part (the case of copying from the low-frequency part to the high-frequency part and the case of copying from the high-frequency part to the low-frequency part) and the low-frequency range. Also, the relationship between the sign of the spectrum of the part and the spectrum of the high-frequency part (whether the positive and negative signs of the spectrum are inverted and copied or not and copied) is also used as auxiliary information. Decoding device 200
In the above, in each of the scale factor bands in the high frequency band, the low frequency band spectrum indicated by the auxiliary information is copied to the high frequency band to restore the high frequency band spectrum. further,
Since the difference in the waveform in the high frequency band is not as clearly audibly discriminated as in the low frequency band, it can be said that the auxiliary information thus obtained is sufficient as information representing the waveform in the high frequency band. .

Here, the quantized value of the spectrum data in each scale factor band in the high frequency band is "1".
Although the scale factor is calculated so that it does not have to be “1”, it may be set to another value. Further, here, only the scale factor is encoded as the auxiliary information, but the present invention is not limited to this, and the quantization value, the characteristic spectrum position information, the sine information representing the positive and negative signs of the spectrum, the noise generation method, etc. May be encoded together. Also, two or more of these may be combined and coded. In this case, in the auxiliary information, if the coefficient indicating the ratio of the amplitude and the position of the absolute maximum spectrum data are encoded in combination with the scale factor,
Especially effective.

In the above embodiment, the sharing determination unit 1
The case where the 37 generates shared information has been described, but the encoding device 100 of the present invention does not necessarily have to generate shared information. In this case, the second encoding unit 13
4 is unnecessary. On the other hand, on the decoding device 200 side,
It is necessary to determine the windows that share the high band spectral data. In this case, the second dequantization unit 224
Has a memory for holding the high band spectral data of at least one window, for example the first
When the inverse quantization unit 222 of FIG. 3 restores the spectrum data of each window by inverse quantization, the high frequency spectrum data of 64 samples including the spectrum data of values other than “0” is held in the memory, and A window in which all spectrum values in the high frequency band are "0" is detected, and high frequency band spectrum data in the memory is output in association with the detected window. For example, the second dequantization unit 224 specifies the detected window number,
The high frequency band spectrum data in the memory is output to the dequantized data synthesis unit 225. As a result, the high frequency band spectral data of the specified window is replaced with the spectral value copied from the memory in the inverse quantized data synthesizing unit 225.

In this case, coding apparatus 100 does not necessarily have to transmit the high band spectrum data of the first window. In this case, on the encoding device 100 side, a window for transmitting high frequency band data is provided in at least the first half of one frame. The second dequantization unit 224 constantly monitors the dequantization result of the first dequantization unit 222,
In the dequantization result of the first dequantization unit 222,
When all the spectrum values in the high frequency band of the window are “0”, the second dequantization unit 224 determines that the window including the subsequent windows includes spectrum data having a value other than “0” in the high frequency band. Search for. As a result of the search,
When a window including spectrum data having a value other than “0” in the high frequency band is obtained, the second dequantization unit 224 outputs the high frequency band spectrum data of the window to the dequantized data synthesis unit 225. . At the same time, the high-frequency part spectrum data is copied to the memory, and is output to the inverse quantized data synthesizing unit 225 so as to be associated with the window detected thereafter and replaced with the value.

As described above, according to the present embodiment, in the conventional case, when a low transfer rate transmission line is used, the high frequency band spectrum data, which is often cut, is distributed for each frame and 8 windows of the SHORT block. At least 1
Since the window portion is transmitted, there is an effect that the decoding apparatus can reproduce an acoustic signal with rich sound quality in a high frequency range as compared with the related art. Further, in the encoding device 100 of the present embodiment, the high frequency band spectrum data is shared between the windows having similar spectra, so that the sound quality of the original sound is improved even in the window in which the high frequency band spectrum data was not transmitted. There is an effect that a similar acoustic signal can be reproduced.

In the present embodiment, the sampling frequency is described as 44.1 kHz, but the sampling frequency is not necessarily limited to this value and may be another value. Also, here, the high frequency part has a frequency of 11.025 kHz.
Although the frequency range is equal to or higher than z, the low-frequency part and the high-frequency part are not necessarily separated at the frequency of 11.025 kHz, and may be divided into a lower range or a higher range.

In the above embodiment, the identification result is attached to the encoding result (encoded shared information etc.) by the second encoding unit 134, and this is used as the second encoded signal in the bit stream. Although the case of storing it in the inside has been described, there is no possibility that encoded information based on another system will be stored in Fill Element, DSE, or the like, or bits that can be decoded only by the decoding device 200 of the present invention. When storing the second coded signal in the stream, it is not necessary to add the identification information. in this case,
The decoding device 200 has a predetermined storage position (for example, F
ill Element), the second encoded signal is unconditionally extracted and the shared information is decoded.

Since this embodiment is effective only when the block size is the SHORT block, when the block size is the LONG block, the internal functions are the same as those of the conventional encoding device 300 and decoding device 400. You may switch to. That is, in this case, in the encoding device 100, the acoustic signal input unit 11
The cutout cycle of 0 is set to 1024 samples, the function is switched to cut out 512 samples before and after the cutout, the unit of MDCT conversion of the conversion unit 120 is switched to 2048 samples, and 1024 samples on one side of the conversion result are Switch to classify into the predetermined 49 scale factor bands. The sharing determination unit 137
The input spectrum data from the conversion unit 120 is output to the first quantization unit 131 as it is, and the second encoding unit 13 outputs the spectrum data.
4 stops functioning. In the decoding device 200, the stream input unit 210 converts the second encoded audio stream into the second audio stream.
Of the second decoding unit 223 and the second decoding unit 223 without extracting the encoded signal of
The inverse quantization unit 224 stops its function, and the inverse quantized data synthesis unit 225 outputs the inputted spectrum data from the first inverse quantization unit 222 to the inverse conversion unit 230 as it is. Thus, the encoding device 100 and the decoding device 20
By making 0 switchable, it is possible to transmit and decode sound data by a LONG block that emphasizes sound quality for slow tempo music and the like, and for up tempo music that frequently attacks, There is an effect that acoustic data by the SHORT block having good followability can be transmitted and decoded.

(Embodiment 2) In the following, with reference to FIG. 11 and FIG. 12, only the points of difference between Embodiment 1 and encoding apparatus 101 and decoding apparatus 201 of the present embodiment will be explained. FIG. 11 is a block diagram showing the configurations of the encoding device 101 and the decoding device 201. <Encoding Device 101> The encoding device 101 is a SHORT.
If the spectral data is similar or similar in two or more windows when encoding with a block, the data of the encoded audio stream to be transmitted by sharing all the quantized data in the windows between the windows. Reduce the amount. The encoding device 101 includes an acoustic signal input unit 110, a conversion unit 120, a first quantization unit 131, and a first quantization unit 131.
The encoding unit 132, the second encoding unit 134, the sharing determination unit 138, and the stream output unit 140.

The sharing determination unit 138 of Embodiment 1 is that the sharing determination unit 138 not only shares the high frequency band spectrum data in the window but also the spectrum data of the entire band in the window including the low frequency band spectrum data. Sharing determination unit 13
Different from 7. That is, when compared with the acoustic signal in the high frequency region, the data amount of the acoustic signal in the low frequency region, which requires auditory strict fidelity to the original sound, is reduced. The sharing determination unit 138 determines a window that shares the quantized data with other windows among the eight windows of the spectrum data output by the conversion unit 120, generates the shared information described above, and also the spectrum value in the window. Are all replaced with "0".

For example, the sharing determination unit 138 shares the spectrum data between the first window and the second window,
In addition, when it is determined that the spectrum data is shared in the windows after the third window, all the spectrum values of the second window and the fourth to eighth windows are “0”.
And the shared information “01011111” is generated. As a result, the sharing determination unit 138 in the first quantization unit 131.
When quantizing the spectrum data output from
Since the spectral values of the second window and the fourth to eighth windows are all “0”, it is possible to quantize with a smaller amount of data than in the conventional case.

<Decoding Device 201> Decoding Device 201
Is a device that decodes the acoustic bitstream encoded by the encoding device 101, and is a stream input unit 210, a first decoding unit 221, and a first dequantization unit 2.
22, second decoding section 223, second dequantization section 22
6, an inverse quantized data combination unit 227, an inverse conversion unit 230, and an acoustic signal output unit 240. Second dequantizer 22
In accordance with the shared information decoded by the second decoding unit 223, 6 displays the spectrum data which is the result of the inverse quantization of the first inverse quantization unit 222 for the window whose flag is represented by “0”. The inverse quantized data synthesizing unit 2 is copied to the memory, and the copied spectrum data is associated with the following window whose flag is represented by "1".
To 27. The inverse quantized data synthesizing unit 227 uses the first
Of the spectrum data output from the inverse quantization unit 222 of
And the spectrum data output from the inverse quantization unit 226 of (1) are combined in window units.

FIG. 12 shows the sharing determination unit 13 shown in FIG.
FIG. 8 is a diagram showing an example of sharing of spectrum data according to No. 8. Similar to FIG. 2B, FIG. 12 shows the spectrum data of the SHORT block for one frame obtained by the MDCT transform. Each such window
The sampling frequency of the input sound data is, for example, 44.1.
In the case of kHz, it represents a reproduction band from 0 kHz to 22.05 kHz.

As described above, since the SHORT block has a short cutout cycle of input acoustic data, the spectra of two adjacent windows are likely to have waveforms similar to each other. In FIG. 12, for example, when it is determined that the spectra of the first window and the second window are similar, and the spectra of the third to eighth windows are similar, the sharing determination unit 138
It is determined that windows having similar waveforms, that is, the first window and the second window share the quantized data of the first window and the third to eighth windows share the quantized data of the third window. To do. In this case, the spectrum data in the range indicated by the arrow in FIG. 12 is the target of transmission (that is, quantization and coding), and the spectrum data of the other second windows and the fourth to eighth windows is the sharing determination unit. 138 replaces all with a value of "0". In this way, the spectral data of the window in which all the values are replaced with the value of “0” is approximately restored by the decoding device 201 by the spectral data copied from the window immediately before the flag of “0”.

As described above, the sharing determination unit 138 can significantly reduce the data amount of the coded bit stream by sharing the spectrum data of the low frequency band between the windows having similar spectra. However, in general, the low-pass spectrum represents an acoustic signal in the low-frequency region that is auditorily sensitive. Therefore, when importance is attached to the sound quality of the reproduced acoustic signal, the sharing determination unit 138 determines that A more rigorous determination is made regarding the similarity of the spectra of. Specifically, the determination criterion is the sharing determination unit 13
The same method as in 7 is used, but in these, for example,
By making the threshold value smaller or using a plurality of judgments in combination, a stricter judgment is made by the sharing judgment unit 137. Further, in this case, for the same reason, the determination of the similarity cannot be omitted, so that only the spectral data of the predetermined window is not transmitted.

The sharing determination unit 138 is the same as that of the first embodiment.
Similar to the sharing determination unit 137, the sharing information does not necessarily have to be generated. In this case, the second encoding unit 134 is unnecessary. For example, when the sharing determination unit 138 performs grouping, for each group, the spectrum data of one or more windows is quantized and encoded as before and transmitted, and all the spectrum data of other windows in the same group are transmitted. After replacing with “0”, it is quantized and encoded and transmitted. In this case, the sharing determination unit 138 generates information about grouping and outputs it to the first quantization unit 131 as in the conventional case. The window for transmitting without replacing the spectrum data in the window with “0” is not necessarily the first window in the group. Also, it is not necessary to share the spectral data of one window within the group.

Incidentally, regarding the grouping, S is conventionally used.
This method will be briefly described because it is a method that is performed by using an existing tool in the HORT block. By this grouping, windows whose spectra are similar to each other are grouped, and the scale factor of each window is shared within each group. It The determination of the similarity of spectra between windows when grouping is performed is the same as the determination criterion when sharing spectrum data. In the SHORT block having a sampling frequency of 44.1 kHz, 14 scale factor bands are conventionally defined in each window, so that 14 scale factors exist in each window. Therefore, as the number of windows grouped into one group increases, the amount of scale factor data to be transmitted can be reduced.

Further, in the determination of the spectral similarity in the grouping described above, the sharing determination unit 138 determines that there is a group having a high similarity between windows,
The average value of the spectrum values of the same frequency of each window in the group is calculated, and the average value of the spectrum values of each frequency is calculated as 12
It is also possible to newly generate a window of 8 samples to be the first window of the group, set all the spectrum values of other windows in the group to “0”, and output the first quantization section 131.

When the coding apparatus 101 does not generate the shared information, the coding apparatus 101 performs grouping between the coding apparatus 101 and the decoding apparatus 201 in advance, and only the first window in the same group has a spectrum. It is agreed that the data will be quantized and encoded as before and transmitted, and "0" will be transmitted as spectrum data for the other windows in the same group. As a result, the second dequantization unit 226 copies the spectrum data of the first window of each group based on the decoded information about the grouping, and copies the copied spectrum data to the second and subsequent ones in the same window. It is output to the inverse quantized data synthesizing unit 227 in association with the window and is synthesized by the inverse quantized data synthesizing unit 227.

If the encoding apparatus 101 does not generate the shared information and does not necessarily transmit the spectrum data of the first window, the second dequantization unit 226
Based on the decoded grouping information, the dequantization result of the first dequantization unit 222 is monitored, and when the first dequantization unit 222 restores the spectrum of a certain window, the dequantization is performed. When the spectrum data whose value becomes “0” as a result of the quantization is detected, the second inverse quantization unit 22
6 refers to the spectrum data of the same frequency in another window in the same group, and if the value is not “0”, copies the value and outputs it to the dequantized data combining unit 227, and dequantizes it. The data combining unit 227 causes the data to be combined.

Alternatively, when the first dequantization unit 222 restores the spectrum of a window and all the spectrum values are “0”, the second dequantization unit 226 determines that the same group The spectrum data in the window including the spectrum data of values other than "0" is copied with reference to the spectrum of other windows in the table, and the inverse quantization is performed by associating with the window in which all the spectrum values are "0". It may be output to the data synthesizing unit 227.

Further, the sharing determination section 138 may output the spectrum data of a plurality of windows in the same group to the first quantization section 131 without replacing it with "0". In this case, in the decoding device 201, when the first dequantization unit 222 restores the spectrum of the window, the second dequantization unit 226 has a value of “0” as a result of dequantization. When the spectrum data that becomes is referred to, the spectrum data of the same frequency in another window in the same group is referred to, and (a) the first non-zero spectrum data found is copied. Alternatively, (b) the spectrum data having the largest spectrum value may be copied, or (c) the spectrum data having the smallest spectrum value may be copied.

Further, in this case, in the decoding device 201, when the first dequantization unit 222 restores the spectrum of a certain window, if the spectrum values are all “0”, the second dequantization unit The quantizer 226 refers to the spectra of other windows in the same group,
Among windows including spectrum data having values other than “0”, (a) the spectrum data of the window having the maximum peak value of the spectrum may be copied, or (b) the spectrum of the window having the maximum energy. You may copy the data.

As described above, according to the present embodiment, 8
By sharing some of the spectral data in one of the two windows with other windows with similar spectra, the amount of data in the coded acoustic bitstream to be transmitted can be reduced while minimizing the loss of reproducibility of the spectral data. The effect is that it can be reduced.

It is needless to say that also in the present embodiment, the amplitude of the spectrum data copied by the second dequantization unit 226 may be adjusted in the decoding apparatus 201 as necessary. To adjust the amplitude, each spectrum data is multiplied by a predetermined coefficient, for example, 0.5. This coefficient may be a fixed value, may be changed for each band, or may be changed according to the spectrum data output from the first inverse quantization unit 222. Although a predetermined coefficient is used in this description, it may be added to the second coded signal as auxiliary information. Alternatively, a scale factor value as a coefficient may be added to the second encoded signal, or a quantized value as a coefficient may be added to the second encoded signal.

Further, in the present embodiment, even for a window whose flag is "0", the spectrum data in the high frequency band is replaced with "0", and instead the data in the high frequency band is used in the first embodiment. The auxiliary information described may be generated. In this case, the shared information and the auxiliary information are coded in the second coded signal. That is, the encoding device 1
In 02, for the window whose flag is "0", only the low band spectrum data is quantized and coded as usual, and "0" is quantized and coded as the high band spectrum data. For the window whose flag is "0", the auxiliary information representing the high frequency band spectrum described in the first embodiment is generated, and the shared information and the auxiliary information are combined and encoded. In response to this, the decoding device 2
In 01, in the window in which the flag of the shared information is “0”, the low frequency band spectrum data is restored by dequantizing the first coded signal in the same manner as in the conventional case, and the high frequency band spectrum data is added to the auxiliary data. Restore based on information.
For the window with the shared information flag of "1", the spectral data of the entire region thus restored in the window with the flag of "0" is copied and restored.

(Embodiment 3) In the following, FIGS.
6, the encoding device 102 and the decoding device 202 in the present embodiment will be described only about the differences from the first embodiment. FIG. 13 shows an encoding device 1 of the present invention.
2 is a block diagram showing the configurations of 02 and a decoding device 202. FIG. <Encoding Device 102> The encoding device 102 restores the spectrum data whose quantization value is “0” because it is adjacent to the absolute maximum spectrum as a result of the quantization in the LONG block, and uses the restored spectrum data in a small amount of data. The quantity is transmitted to the decoding device 202. The encoding device 102
Acoustic signal input unit 111, conversion unit 121, first quantization unit 151, first coding unit 152, second quantization unit 15
3, the second encoding unit 154, and the stream output unit 160
Composed of.

The acoustic signal input section 111 has a frequency of 44.1.
MP sampled at a sampling frequency of kHz
Digital acoustic data, which is an input signal similar to that of EG-2 AAC, is cut out in a cycle of about 23.2 msec (every 1024 samples) by overlapping 512 samples before and after that.

The transform unit 121 uses MDCT to overlap the 1024 input signal points with the data of 512 samples before and after, and convert the time axis data of 2048 samples to 2
Convert to spectral data of 048 samples. Furthermore, since the conversion unit 121 produces bilaterally symmetrical spectrum data in MDCT, one or more samples of the spectrum data of one of the 1024 samples (practically 4
Multiple scale factor bands containing spectral data of multiples of. Here, since digital audio data having a sampling frequency of 44.1 kHz is input, the number of scale factor bands included in one frame of the LONG block is 49.

The first quantizing unit 151 inputs the spectrum data output from the converting unit 121, determines the scale factor for each scale factor band of the input spectral data, and determines the scale factor with the determined scale factor. The spectrum in the scale factor band is quantized, and the quantized value that is the quantized result is output to the first encoding unit 152.

The first coding unit 152 has a quantization value in each scale factor band corresponding to the 1024 samples of the spectrum data quantized by the first quantization unit 151 and a scale factor used for the quantization. Is subjected to Huffman coding as a first coded signal and converted into a predetermined stream format.

The second quantizing unit 153 monitors the quantization result of the first quantizing unit 151 and is adjacent to the absolute maximum spectrum data (spectrum data having the maximum absolute value) in each scale factor band. Therefore, the spectrum data of each of the 5 samples before and after the quantized value becomes “0” by the quantization of the first quantizing unit 151, that is, a total of 10 samples is specified. The second quantization unit 153 quantizes the spectrum value input from the conversion unit 121 with respect to the specified spectrum data, using a predetermined scale factor between the encoding device 102 and the decoding device 202, Only the quantized value is expressed with a smaller data amount and output to the second encoding unit 154.

The second encoder 154 Huffman-encodes only the quantized value output by the second quantizer 153 into a predetermined stream format and outputs it as a second encoded signal. The scale factor used in the second quantizer 153 is not encoded.

The stream output section 160 adds header information and other sub-information as necessary to the first coded signal output from the first coding section 152 to make MPEG-2.
Convert to an AAC encoded bitstream, and
The second encoded signal output from the encoding unit 154 of
The bit stream is stored in an area which is ignored by the conventional decoding device or whose operation is not specified.

<Decoding Device 202> Decoding Device 202
Is adjacent to the peak, the spectral data whose quantized value becomes “0” by the quantization is the second decoded data.
A decoding device that restores the encoded signal according to the above-described encoded signal, the stream input unit 260, a first decoding unit 251, a first dequantization unit 252, a second decoding unit 253, and a second dequantization unit. It is composed of a unit 254, an inverse quantized data synthesizing unit 255, an inverse transforming unit 231, and an acoustic signal output unit 241.

The stream input section 260 includes the encoding device 1
The encoded bit stream generated in 02 is input, the first encoded signal and the second encoded signal are extracted from the input encoded bit stream, and the first encoded signal and the second encoded signal are extracted, respectively.
To the second decoding unit 251 and the second decoding unit 253.

The first decoding section 251 receives the first coded signal output from the stream input section 260 and decodes the Huffman coded data from the stream format into quantized data. First dequantization unit 252
Dequantizes the quantized data decoded by the first decoding unit 251, and reproduces the band of 22.05 kHz, 102
Output the spectral data of 4 samples.

The second decoding section 253 inputs the second coded signal output from the stream input section 260, decodes the input second coded signal, and outputs the absolute maximum in each scale factor band. The quantized value of each of the 5 samples before and after which it adjoins a spectrum is output.

The second dequantization section 254 dequantizes the quantized value output from the second decoding section 253 using a predetermined scale factor, and samples each adjacent 10 samples before and after the absolute maximum spectrum. Generate the spectral data of. The second dequantization unit 254 is the first dequantization unit 25.
Based on the spectrum data output from 2, the frequency of the spectrum data of 10 samples whose quantized value became “0” because they were adjacent before and after the absolute maximum spectrum was specified, and the spectrum of the generated 10 samples The data is output to the dequantized data synthesizing unit 255 in association with the specified frequency.

The inverse quantized data synthesizer 255 includes the spectrum data output from the first inverse quantizer 252 and the second
The spectrum data output from the inverse quantization unit 254 of 1 is combined and output to the inverse conversion unit 231. Specifically, the inverse quantized data synthesizer 255 is the value of the spectrum data output from the second inverse quantizer 254 in association with the frequency, which is the output of the first inverse quantizer 252. Replace frequency spectral data. The inverse transforming unit 231 uses the inverse quantized data synthesizing unit 255 to synthesize 10 signals on the frequency axis.
The spectral data of 24 samples is converted into an acoustic signal on the time axis using IMDCT. Acoustic signal output unit 24
1 sequentially combines the sample data on the time axis obtained by the inverse conversion unit 231, and outputs it as digital audio output data.

As described above, the encoding device 102 of the present invention.
Also, according to the decoding device 202, the quantized value is “1” by encoding the spectrum data before and after the absolute maximum spectrum data in each scale factor band using a scale factor different from that of the first quantization unit 151. Since the spectrum data that has been set to "0" is restored, the accuracy in the vicinity of the peak in the entire reproduction band is improved, and it is possible to perform encoding with higher sound quality.

Here, the second inverse quantizer 254 is used.
Quantized using the spectrum data that is the output from the conversion unit 121, but the output from the conversion unit 121 does not necessarily have to be used. For example, the first quantization unit 15
The quantized value of 1 may be inversely quantized and used. The configuration of the encoding device 102 in this case is shown in FIG. 14 below.

FIG. 14 is a block diagram showing another configuration of the encoding device 102 and the decoding device 202. The encoding device 102 includes an acoustic signal input unit 111, a conversion unit 121, a first quantization unit 151, a first encoding unit 152, a second quantization unit 156, a second encoding unit 154, and an inverse quantum. Conversion unit 15
5 and the stream output unit 160.

The second quantizing unit 156 is the inverse quantizing unit 15
5, the quantization result of the first quantization unit 151 is monitored, and among the spectrum data quantized by the first quantization unit 151, the quantization value is set because it is adjacent before and after the absolute maximum spectrum data. The spectrum data of 10 samples having "0" is specified, and the specified spectrum data is input from the inverse quantization unit 155 and quantized using a predetermined scale factor.

The inverse quantizer 155 has the first quantizer 15
The quantized value that is the quantized result of 1 is inversely quantized, and the quantized value and the spectrum value corresponding to the quantized value are output to the second quantizing unit 156. Operations of the encoding apparatus 102 and the decoding apparatus 202 configured as above will be described below with reference to FIGS. 15 and 16.

First quantizer 151 of encoding apparatus 102
In the same manner as before, when the quantization is performed by adjusting the scale factor so as to match the encoded data amount with the transfer rate of the transmission line, the spectrum data before and after the absolute maximum spectrum data is continuously "0". Often happens. When such a quantized value is restored in the decoding device 202 as it is, only the absolute maximum spectrum data is correctly restored, and the spectrum data adjacent to both sides thereof become “0”,
There is a problem that the amount becomes a quantization error and the sound quality of the acoustic signal output from the decoding device 202 deteriorates.

Therefore, if the spectrum data before and after the absolute maximum spectrum data is quantized so as not to be "0" by adjusting the value of the scale factor, this time the neighboring spectrum data including the absolute maximum spectrum data will be quantized. The quantized values of will be large numbers. The data amount of the encoded bitstream obtained by encoding these depends on the maximum value of the quantized value, and the larger the maximum value of the quantized value, the more the data amount of the encoded bitstream tends to increase. Therefore, in transmitting the encoded bit stream through the transmission path,
This method is not realistic.

FIG. 15 is a table 500 showing the difference in the quantization result between the conventional coding apparatus 300 and the coding apparatus 102 of the present invention using concrete values. First, in the conventional encoding device 300, when spectrum data 501 such as {10, 40, 100, 30} is output from the conversion unit 320, as in the table 500, the quantization unit 331 generates encoded bits. When the scale factor is adjusted according to the amount of data for one frame of the stream and quantization is performed, the quantized value 502 becomes, for example, {0, 0, 1,
0}, and the absolute maximum spectrum data “10
The value of the spectrum data adjacent to "0" will be "0". In the conventional encoding device 300, the quantization value 5
No. 02 has to be adopted, and this quantized value 502 is encoded. As a result, in the decoding apparatus 400 that receives this, the value of the spectrum data 505 restored by the dequantization unit 422 becomes {0, 0, 100, 0}.

On the other hand, in the encoding device 102 of the present invention, when the same spectrum data 501 of {10, 40, 100, 30} is output from the conversion unit 121, the first quantization unit 151 performs quantization. The value 502 is
It becomes {0, 0, 1, 0}. Encoding device 102 of the present invention
Then, in such a case, the first quantization unit 151 outputs the quantized value 502 as it is. In the encoding device 102, in order to compensate for this, the second quantizing unit 153 further quantizes the same spectrum data using a predetermined scale factor. If the quantized value 503 by the second quantizer 153 is {1, 4, 10, 3}, the minimum quantized value is "1", so the scale factor should be reduced further. This value becomes "0" as you go. Therefore, the quantized value 503 is the quantized value in which the data amount of the coded data is reduced most in the range where the spectral data before and after does not become “0”, but the maximum quantized value is still “10”. .

On the other hand, in the second quantizing section 153, in order to further reduce the data amount of the quantized value, if the quantized result is the quantized value 503 {1, 4, 10, 3}, this The quantized value is, for example, quantized value 504 {1, 2, 0,
2} is expressed using exponential function display or the like.

Specifically, the first sample "1" is 2
"2" is expressed as the first power of, and "2" in the second sample is
"4" is represented as the square of 2. "0" in the third sample
Indicates that the spectral data at this position is the absolute maximum spectral data. The spectrum value of the absolute maximum spectrum data is correctly obtained from the scale factor (obtained by the first quantization unit 151) obtained from the first encoded signal and its quantized value "1". By omitting the encoding of the spectrum value of the absolute maximum spectrum data in each scale factor band in this way, the data amount of the second encoded signal can be further reduced. "2" of the fourth sample
Represents "4" as the square of 2. Such an expression is
The quantized value 503 {1, obtained by the second quantizer 153,
4, 10, 3} does not match exactly, but the quantized value is 50
The quantized value of each sample can be represented by at most 2 bits like 4 {1, 2, 0, 2}. In the decoding device 202, the quantized value 502 obtained from the first encoded signal
When the spectrum data is restored based on the quantized value 504 obtained from the second encoded signal and the quantized value 504, spectrum data 505 {20, 40, 100, 40} is obtained.

In this way, according to the encoding device 102,
By expressing the quantization result of the second quantization unit 153 as described above, when the data amount of the second coded signal is suppressed to the minimum while the data amount is reduced to "0" in the conventional method. The spectrum data before and after the peak that has become “” can be restored with a rough but approximate value, and an acoustic signal more faithful to the original sound can be restored.

Here, the quantization result of the second quantizing unit 153 is represented by a power of "2", but the base value does not have to be "2", and it need not be an integer. , Any numerical value may be used. Furthermore, the function representing the quantization result of the second quantization unit 153 does not need to be an exponent, and may be another function.

FIG. 16 is a diagram showing an example of correction of the quantization error around the peak by the encoding device 102. FIG.
13A is a waveform diagram showing a part of the spectrum output from the conversion unit 121 shown in FIGS. 13 and 14. FIG. In the figure, the range indicated by the alternate long and short dash line shows one scale factor band (sfb), and the broken line shows the frequency of the absolute maximum spectrum data of the scale factor band. Further, the range indicated by the chain double-dashed line shows the spectrum data of a total of 10 samples adjacent before and after the absolute maximum spectrum. FIG. 16B is a diagram obtained by the first quantizer 151 shown in FIGS. 13 and 14.
It is a figure which shows an example of the quantization result of the spectrum part of (a). FIG. 16C is the second diagram shown in FIGS. 13 and 14.
FIG. 17 is a diagram showing an example of a quantization result of the spectrum part of FIG. 16A by the quantization units 153 and 156 of FIG. FIG.
In (a), FIG. 16 (b), and FIG. 16 (c), the horizontal axis represents frequency. In addition, in FIG. 16A, the vertical axis represents the spectrum value. 16B and 16C, the vertical axis represents the quantized value.

The spectral data of one scale factor band is normalized and quantized using the same scale factor. For example, when the absolute maximum spectrum data has a relatively large value as shown in FIG.
If the scale factor is adjusted based on the bit amount of one frame as a whole, the value of the scale factor cannot help being reduced. As a result, as shown in FIG. 16B, as a result of quantization, only the absolute maximum spectrum data has a value other than "0", and the values of the other spectrum data often become "0". . The first quantization unit 151 outputs such a quantization result as it is to the first encoding unit 152. In the encoding device 102, on the other hand, the second quantizer 153
The quantization result as shown in FIG. 16 (c) is transmitted as the second coded signal. The second quantizer 153 outputs "0" as the quantized value of the absolute maximum spectrum data, and quantizes 10 samples before and after that.

Since the second quantizer 153 quantizes using a predetermined scale factor, if the value is not much different from the scale factor used by the first quantizer 151, It cannot always be said that the quantized value which has become “0” in the first quantizer 151 takes a value other than “0” in the second quantizer 153. However, by defining an appropriate scale factor for each scale factor band in advance in the second quantizing unit 153, the first quantizing unit 151 that has become “0” in more scale factor bands. The quantization result of can be restored as shown in FIG.

That is, the second quantizer 153
16B is obtained from the transform unit 121 shown in FIG. 13 or the inverse quantization unit 155 shown in FIG. 14 for the spectrum data for which the quantization result of the quantization unit 151 of FIG. Then, quantization is performed between the encoding device 102 and the decoding device 202 using a predetermined scale factor, and the quantization result is
It is expressed by a shorter bit amount and is output to the second encoding unit 154. As described above, the second quantizer 153 does not encode these scale factors and functions by using the scale factors and functions that are predetermined between the encoding device 102 and the decoding device 202. Never quantize absolute maximum spectral data. The quantized values of 10 samples adjacent before and after the absolute maximum spectrum data are further expressed as a function. With these, the data amount of the second coded signal can be minimized.

In the present embodiment, the first quantizing unit 15 is provided because it is adjacent to the absolute maximum spectrum data.
Although the case where the second quantization unit 153 redoes the quantization of the spectrum data in which the quantization result by 1 is continuously “0” has been described, the spectrum data to be quantized again is not necessarily continuous. If the quantized value is "0" in the vicinity of the absolute maximum spectrum data, the corresponding spectrum data may be decoded in the same manner as above even if they are not adjacent to each other. It is possible to correct the spectral values that have been obtained. Specifically, the second quantizer 153 is the first quantizer 1
From the quantization result of 51, spectrum data having a quantized value of “0” in the vicinity of the absolute maximum spectrum data is identified by 5 samples on both sides of the absolute maximum spectrum data, and the identified spectrum data has already been described. As described above, the quantization is performed using the predetermined scale factor, and the quantization result is represented by a shorter bit amount and output to the second encoding unit 154. In the decoding device 202, from the dequantization result of the first dequantization unit 252, the spectrum data having a quantized value of “0” in the vicinity of the absolute maximum spectrum data is provided on both sides of the absolute maximum spectrum data, respectively. Five samples are specified, and the spectrum values obtained by decoding and dequantizing the second encoded signal are output to the dequantized data combining unit 255 in association with the specified spectrum data. Further, in the above embodiment, the second quantizer 153 quantizes a total of 10 samples before and after the absolute maximum spectrum data, but the number of samples need not necessarily be 5 samples before and 5 samples after. Not,
It may be more or less than 5 samples. Further, the second quantizing unit 153 may determine the number of samples according to the data amount of the coded bitstream of each frame. In this case, the quantized value of each sample and the number of samples may be combined and coded in the second coded signal.

Further, in the present embodiment, the scale factor corresponding to the quantized value transmitted as the second coded signal is set to a predetermined value, but the optimum scale factor value is set for each scale factor band. May be calculated and added to the second encoded signal for transmission. For example, if the scale factor is selected so that the maximum quantized value is “7”, there is an effect that the amount of data required to transmit the quantized value can be smaller.

In this embodiment, only the quantized value by the second quantizing section 153 or only the quantized value and the scale factor are coded in the second coded signal, but the present invention is not limited to this. It doesn't have to be a thing. That is, in the encoding apparatus 102, when all the quantized values of 10 samples adjacent before and after the absolute maximum spectrum data of each scale factor band become “0”, the quantization is performed using a predetermined scale factor. Further, the auxiliary information representing the high frequency band spectrum described in the first embodiment may be generated, and the quantization result of the second quantization unit 153 and the auxiliary information may be combined and encoded. . In this case, the quantization value and the scale factor of the high frequency band are not transmitted, and the decoding device 202 restores the high frequency band spectrum data based on the auxiliary information. Although the auxiliary information in the SHORT block has been described in FIGS. 9 and 10 and the rewriting of the first embodiment, the auxiliary information can be similarly generated in the LONG block. However, since it is a LONG block here, if the high-frequency part and the low-frequency part are divided at a position where the number of samples is half, 64 blocks of the high-frequency part in the SHORT block and 512 samples of the high-frequency part in the LONG block are supplemented. Generate information. Further, the scale factor band also follows the scale factor band of the LONG block. By doing so, there is an effect that the data amount of the encoded bit stream can be further reduced by the quantization value and the scale factor in the high frequency band.

As this auxiliary information, one auxiliary information is generated for each scale factor band.
One piece of auxiliary information may be generated for each of two or more scale factor bands, or two or more pieces of auxiliary information may be generated for one scale factor band. The auxiliary information in this embodiment may be encoded for each channel, or one auxiliary information may be encoded for two or more channels.

In this case, when the high frequency band spectrum is restored based on the auxiliary information, the low frequency band spectrum data is copied as the high frequency band spectrum data, but the present invention is not limited to this. The side spectral data may be generated only from the second coded signal. In addition, the configurations of the encoding device and the decoding device in the present embodiment are such that the second quantizing unit and the second encoding unit are added to the conventional encoding device, and the second decoding is performed in the decoding device. Since it is merely the addition of the section and the second dequantization section, it can be realized without significantly changing the existing coding apparatus and decoding apparatus.

In this embodiment, M is used as a conventional technique.
Although the PEG-2 AAC has been described as an example, it is apparent that the present invention can be applied to other acoustic coding schemes and to new acoustic coding schemes that do not exist. Also in this embodiment, as in the first embodiment, the second coded signal may be added after the first coded signal as shown in FIG. 4B, and FIG. As described above, the second coded signal may be added immediately after the header information. However, in the case of the present embodiment, since it is a LONG block, the first coded signal for one frame corresponds to an acoustic signal of 1024 samples. By doing so, even in the conventional decoding device 400, this coded bit stream can be reproduced without any trouble. Also, the second coded signal may be incorporated into the first coded signal,
It may be embedded in the header information, or a continuous area may not be secured for the incorporation. Further, it is not limited to these. FIG. 4A is a data layout diagram when the second coded signal is discontinuously incorporated in the header information and the coded information as shown in FIG. Further, as shown in FIG. 5, the second coded signal may be stored in a completely different stream from the bit stream in which the first coded signal is stored. By doing so, there is an effect that the basic part of the input audio signal can be transmitted or accumulated in advance, and the high frequency information can be added later if necessary.

In the present embodiment, the number of quantizers and encoders is two, but the number of quantizers and decoders is not limited to this, and three or more quantizers and decoders may be provided.
In the present embodiment, the decoding unit and the dequantization unit are 2
However, the present invention is not limited to this, and three or more decoding units and inverse quantization units may be provided.

The above processing can be realized not only by hardware but also by software, or by a structure in which a part is realized by hardware and the rest is realized by software.

The coding devices 100 and 10 of the present invention are as follows.
1, 102 are provided on the broadcasting station side of a distribution system for distributing contents, and are decoding devices 200, 20 of the present invention.
The audio coded bitstream of the present invention may be output as an audio signal to the receiving device including the elements 1 and 202.

[0158]

As described above, according to the coding apparatus of the present invention, the conversion means is a coding apparatus for coding the input acoustic signal, and the input acoustic signal is cut out at regular intervals to obtain the frequency. By converting into a spectrum, a plurality of sets each consisting of a set of spectrum data are generated every one frame time. The sharing determination means compares the pairs obtained by the conversion means, and when the spectra of the pairs are similar to each other in a range satisfying a predetermined determination criterion,
It is determined that the high band spectral data of one set is shared by the other set. The replacing means replaces the high band spectral data of the other set with a predetermined value for the other set determined to share the high band spectral data. The first quantizing means quantizes the spectral data of each set after the replacement processing by the replacing means. The first encoding means encodes the quantization result obtained by the first quantization means. The output means outputs the data encoded by the first encoding means.

Therefore, when the conversion means generates a plurality of sets each consisting of a set of spectrum data for each frame time, there is a possibility that the spectra are originally similar to each other in the temporally adjacent sets. high. On the other hand, in the encoding device of the present invention, based on the determination by the sharing determination means, for the other set that is similar to each other, the high band spectrum data is not quantized and encoded, and the one set is not set. Substitute the high-frequency spectrum data of. Specifically, for the other set, the high frequency band spectrum data of that set is replaced with a predetermined value. If this predetermined value is set to, for example, "0", the quantization and coding processing of that portion can be simplified, and the amount of coded data in the high frequency region can be significantly reduced. is there.

In response to this, according to the decoding apparatus of the present invention, the judging means monitors the dequantization result of the first dequantizing means and outputs it by the first dequantizing means. When the value of the high frequency band spectrum data is a predetermined value, the set is determined to be the other set. The second dequantization means is based on the judgment of the judgment means,
From the dequantization result of the dequantization means, the spectrum data representing the high frequency part of the one set is copied, and the copied spectrum data is output in association with the other set. The acoustic signal output means outputs the value of the high frequency band spectrum data of the set which is the high frequency band spectrum data output by the first dequantization means and which is associated by the second dequantization means. After substituting with the value of the high frequency band spectrum data output by the second inverse quantizing means, inverse transformation is performed,
Output as an acoustic signal on the time axis. In this, the second dequantization means copies the spectrum data representing the high frequency part of the one set based on the determination of the determination means, and outputs the copied spectrum data in association with the other set. To do.

As a result, in the decoding device of the present invention, at least one set of high frequency band data is input for one frame, and based on the judgment of the judgment means,
Since the data can be restored by copying it to the other set, there is an effect that it is possible to reproduce a high-quality sound signal having a richer high frequency band as compared with the related art.

Further, according to the encoding device of the present invention, the sharing determination means adds to the high-frequency part of the one set when the spectra of the sets are similar to each other in a range satisfying a predetermined determination criterion. Furthermore, it is determined that the spectrum data of the low frequency part is shared by the other pair, and the replacing means adds the high frequency part of the pair for the other pair determined to share the spectrum data. Further, the spectrum data in the lower frequency band is replaced with a predetermined value.

Therefore, when the spectra of the pairs are similar to each other within a range satisfying a predetermined judgment criterion, the spectrum data of the low band part in addition to the high band part is replaced with a predetermined value. For example, when it is set to “0”, the quantization and coding process of that part can be simplified, and the amount of coded data of the acoustic signal can be significantly reduced to the low frequency part. The effect is that you can do it.

Correspondingly, in the decoding device of the present invention, the first decoding means decodes the data encoded by the first encoding means in the input encoded data. The first dequantization means dequantizes the decoding result of the first decoding means and outputs the spectrum data of each set. The determination means monitors the dequantization result of the first dequantization means, and if the value of all the spectrum data output by the first dequantization means is a predetermined value, the set is set to the other one. It is determined to be a set of. The second dequantization means copies all the spectrum data of the one set from the dequantization result of the first dequantization means based on the judgment of the judgment means, and the copied spectrum data of the other set. Output in association with the set. The acoustic signal output means outputs the spectrum data outputted by the first dequantization means, and the values of all the spectrum data of the set associated by the second dequantization means, by the second dequantization. After replacing with the value of the spectrum data output by the means, it is inversely transformed and output as an acoustic signal on the time axis.

Therefore, according to the decoding apparatus of the present invention, 1
Since at least one set of whole-area data is input to the frame and is restored by copying it to the other set based on the judgment of the judging means, the low-frequency part has a predetermined value as compared with the conventional one. Although some errors occur depending on the range of the judgment standard, it is possible to reproduce a high-quality sound signal rich in the higher frequency band based on the high frequency band data input for at least one set per frame. There is an effect.

Further, in the encoding apparatus of the present invention, the conversion means cuts out the input acoustic signal at regular time intervals and converts it into a frequency spectrum. The first quantizing means quantizes the spectrum data obtained by the converting means. The second quantizing means, in the spectral data input to the first quantizing means, in the first quantizing means,
When the quantization result of the spectrum data adjacent to the peak of the spectrum has a predetermined value continuously, it is re-quantized using a predetermined normalization coefficient. The first encoding means is the first
The quantization result of the quantization means is encoded. The second encoding means encodes the quantization result of the second quantization means. The data encoded by the first encoding means by the output means outputs the data encoded by the second encoding means.

Therefore, according to the encoding apparatus of the present invention, the second quantizing means continuously quantizes the spectrum data adjacent to the peak of the spectrum to the predetermined value in the first quantizing means. Since the thing is re-quantized using a predetermined normalization coefficient, the quantization result of the spectrum data adjacent to the peak can be re-quantized to a value which is not continuous at a predetermined value. That is, there is an effect that the quantization error of the spectrum data adjacent to the peak can be corrected by the quantization of the second quantization means.

Correspondingly, in the decoding device of the present invention, the encoded data separating means separates the data encoded by the second encoding means from the input encoded data. The first decoding means decodes the data encoded by the first encoding means in the input encoded data. The first dequantization means dequantizes the decoding result of the first decoding means and outputs the spectrum data of each band. The second decoding means decodes the data encoded by the second encoding means. The second dequantization means dequantizes the decoding result of the second decoding means using a predetermined normalization coefficient, and since it is adjacent to the spectrum data having a peak in each band, the first quantization means Then, the continuous spectrum data whose quantization result is a predetermined value is restored. The acoustic signal output means includes a plurality of spectra which are adjacent to each other before and after one spectrum data of the spectrum data output by the first dequantization means, and each of which continuously has a predetermined value. The data value is replaced with the value of the spectrum data restored by the second inverse quantization means, and then inversely transformed and output as an acoustic signal on the time axis.

Therefore, according to the decoding device of the present invention, since the second dequantization means is adjacent to the spectrum data having the peak in each band, the quantization result by the first quantization means has a predetermined value. Since the lost continuous spectrum data is restored, the quantization error of the spectrum data adjacent to the peak can be corrected by the quantization of the second quantization means. As a result, there is an effect that the acoustic signal around the peak of the spectrum can be reproduced more faithfully to the original sound in the entire reproduction band of the acoustic signal.

[Brief description of drawings]

FIG. 1 is a block diagram showing configurations of an encoding device and a decoding device according to the present invention.

FIG. 2 is a diagram showing a conversion process of an acoustic signal processed in the encoding device shown in FIG.

FIG. 3 is a diagram showing an example of sharing of high frequency band data by a sharing determination unit shown in FIG. 1.

FIG. 4 is a diagram showing a data structure of a bitstream in which a second encoded signal (shared information) is stored by the stream output unit shown in FIG.

5 is a diagram showing another data structure of a bitstream in which a second encoded signal (shared information) is stored by the stream output unit shown in FIG.

FIG. 6 is a flowchart showing an operation in a scale factor determination process of the first quantizer shown in FIG.

7 is a flowchart showing an example of an operation in a one-frame sharing determination process of the sharing determination unit shown in FIG.

8 is a flowchart showing an operation in a copy process of high frequency band spectrum data of the second dequantization unit shown in FIG. 1. FIG.

9 is a spectrum waveform diagram showing a specific example of auxiliary information (scale factor) generated for one window of a SHORT block by the sharing determination unit shown in FIG.

10 is a flowchart showing an operation in auxiliary information (scale factor) calculation processing of a sharing determination unit shown in FIG.

FIG. 11 is a block diagram showing configurations of an encoding device and a decoding device.

12 is a diagram showing an example of sharing of spectrum data by a sharing determination unit shown in FIG.

FIG. 13 is a block diagram showing the configurations of an encoding device and a decoding device according to the present invention.

FIG. 14 is a block diagram showing another configuration of the encoding device and the decoding device.

FIG. 15 is a table showing the difference in quantization result between the conventional encoding device and the encoding device of the present invention using concrete values.

FIG. 16 is a diagram showing an example of correction of a quantization error around a peak by the encoding device.

FIG. 17 is a block diagram showing a configuration of a conventional MPEG-2 AAC encoding device and decoding device.

[Explanation of symbols]

100 encoder 110 Acoustic signal input section 120 converter 131 First Quantizer 132 first encoding unit 134 Second Encoding Unit 137 Sharing determination unit 140 stream output section 200 Decoding device 210 Stream input section 221 First Decoding Unit 222 First dequantization unit 223 second decoding unit 224 Second dequantization unit 225 Dequantized Data Synthesis Unit 230 Inverse converter 240 Acoustic signal output section

[Procedure amendment]

[Submission date] January 10, 2003 (2003.1.1
0)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

[0018]

In view of the above-mentioned problems, an encoding apparatus of the present invention is an encoding apparatus for encoding an input acoustic signal, the input acoustic signal being cut out at regular intervals to obtain a frequency. A conversion means for generating a short block spectrum composed of a plurality of windows showing a time change of the frequency spectrum by converting into a spectrum, and the conversion means obtains the short block spectrum. comparing the window together, whether spectrum thereof windows each other to similar in the range satisfying the predetermined criteria
A shared determination means for determining whether said window between the scan
If the vectors are similar within the above range, another window
With regard to the shared window to share the high-frequency band spectrum of,
Replacement means for replacing the high frequency band spectrum data of the shared window with a predetermined value, first quantization means for quantizing the spectrum data of each window after the replacement processing by the replacement means, and the first quantization. It is characterized by further comprising: first encoding means for encoding the quantization result by the means, and output means for outputting the data encoded by the first encoding means.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

In response to this, the decoding apparatus of the present invention is
A decoding device for decoding input coded data representing an acoustic signal , comprising: a first area in the input coded data;
A first decoding means for decoding the first encoded data that is recorded, the decoding results by the first decoding means and inverse quantization, every one frame time, when the frequency spectrum
First dequantizing means for outputting a plurality of short block spectra showing inter-change, and a result of dequantizing by the first dequantizing means is monitored and output by the first dequantizing means. among the windows were, when the value of the space <br/> Kutorudeta frequency higher band has become a predetermined value, the WE
The high frequency spectrum data in the window
Generated by referring to the high band spectral data of the window
Determining means for determining that the reference window is a reference window to be used, and the first dequantizing means based on the determination by the determining means .
From the inverse quantization result , the reference window is referenced.
Copy the high frequency spectrum data of the referenced window , which is the window , and copy the spectrum data
A second inverse quantization means for outputting in association with the reference window, the predetermined output by the first inverse quantization means
A higher frequency band spectrum data value, the reference Win
The value of the high frequency band spectrum data of the dough is associated with the second dequantization means and output by the referenced wave.
After replacing with the value of the high frequency band spectrum data of the window , it is inversely transformed and is output as an acoustic signal on the time axis.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

Further, according to the encoding device of the present invention, the sharing determination means determines whether or not the spectra of the windows are similar to each other within a range satisfying a predetermined determination criterion,
The replacement means is arranged such that the spectrum between the windows is
When similar in the range, the high frequency range of other windows
For each sharing window that shares the story,
Spectral data of the further low-frequency portion of the window substituted to a predetermined value.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

Correspondingly, in the decoding device of the present invention, the determining means is such that the values of all spectrum data in each of the windows output by the first dequantizing means are predetermined values. , The window is determined to be the reference window , and the second dequantizer
The stage , based on the determination by the determining means , determines the predetermined referenced wave from the dequantization result of the first dequantizing means.
All spectral data including the low-frequency part of the window are copied, and the copied spectral data is used for the reference window.
Output in association with the dough , the acoustic signal output means,
The values of all the spectrum data in the reference window are associated with the second dequantization means and output by the output target.
After substituting with the values of the spectral data in the reference window ,
Inverse transform, you output as an acoustic signal on the time axis.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

Further, the encoding device of the present invention further comprises:
Among the spectrum data input to the first quantizing means, the spectrum data which is close to the peak of the spectrum as a result of the quantization by the first quantizing means and has a predetermined quantizing result has a predetermined value. comprising a second quantizing means for re-quantized using the normalization factor, and a second encoding means for encoding the quantized result of the second quantization means, the output
The means outputs the data encoded by the first encoding means and the data encoded by the second encoding means.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

In response to this, the decoding device of the present invention is
Further, from the second region in the input encoded data, the
Regarding the same spectrum data, the first encoded data is
Second code quantized using different predetermined normalization coefficient
A second coded data separating means for separating data, the
A second decoding means for decoding second coded data, wherein
The decoding result by the first decoding means is monitored and the decoding is performed.
Specify the part that has a predetermined value continuously in the conversion result and specify
The decoding result by said second decoding means corresponding to the portion, and inverse quantized using said predetermined normalization factor, double
Second dequantization means for generating a number of spectral data;
After replacing the value of the spectrum data of the specified portion of the spectrum data output by the first dequantization unit with the value of the spectrum data generated by the second dequantization unit, the inverse transform is performed. And an audio signal output means for outputting as an audio signal on the time axis.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0102

[Correction method] Change

[Correction content]

For example, the sharing determination unit 138 determines that the first window and the second window share the spectrum data of the first window , and the windows after the third window also share the spectrum data of the third window . In this case, all the spectrum values of the second window and the fourth to eighth windows are set to “0”, and the shared information “0” is set.
1011111 ”is generated. As a result, when the spectrum data output from the sharing determination unit 138 is quantized by the first quantization unit 131, all the spectrum values of the second window and the fourth to eighth windows are “0”.
Therefore, it is possible to quantize with a smaller amount of data compared to the conventional one.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0158

[Correction method] Change

[Correction content]

[0158]

Encoding apparatus of the present invention as described above, according to the present invention, there is provided a coding apparatus for coding an input audio signal, by converting the frequency spectrum cut out an input audio signal at predetermined time intervals Frequency at every 1 frame time
It consists of several windows that show the time variation of several spectra.
A conversion means for generating a short block spectrum ,
A sharing determination that compares the windows obtained by the conversion means and determines whether the spectra of the windows are similar to each other within a range satisfying a predetermined determination criterion.
Means and the spectrum between the windows is within the range
In the case of similar, per shared window <br/> share a high frequency band spectrum of the other windows, replacement means for replacing the higher band spectrum data of the shared window to a predetermined value
If, after replacement process by the replacement section, each window
A first quantizing means for quantizing the spectral data of c .
First for encoding the quantized result of the first quantizing means
The encoding means and the output means for outputting the data encoded by the first encoding means are provided .

[Procedure Amendment 10]

[Document name to be amended] Statement

[Name of item to be corrected] 0159

[Correction method] Change

[Correction content]

Therefore, the converting means is configured to display a plurality of windows indicating the time change of the frequency spectrum for each frame time.
When generating a short block spectra consisting of c inherently Wie temporally adjacent in cut
It is highly likely that spectra will be similar between windows . On the other hand, in the encoding device of the present invention, based on the judgment by the sharing judgment means, the sharing wisdom that is similar to each other is shared.
For windows , the high-frequency spectrum data is not quantized and encoded, and the high-frequency spectrum data of the other window is used instead. Specifically, per <br/> in the shared window, thus replacing the high frequency band spectrum data of the window to a predetermined value. If this predetermined value is set to, for example, "0", the quantization and coding processing of that portion can be simplified, and the amount of coded data in the high frequency region can be significantly reduced. is there.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Name of item to be corrected] 0160

[Correction method] Change

[Correction content]

The decoding apparatus of the present invention corresponding to this is
Decoding device for decoding input coded data representing a sound signal
In the first area of the input coded data.
First decoding for decoding recorded first encoded data
Means and inverse decoding the decoding result by the first decoding means.
The frequency spectrum time for each frame time.
Output multiple short block spectra showing changes
That a first inverse quantization means, the inverse quantization result by the first inverse quantization means to monitor, among the windows that have been output by said first inverse quantization means, spectrum of the frequency high-band portion <br / > If the value of the torque data is the specified value, the win
Dow the high frequency spectrum data in the window
Generated by referring to the high band spectral data of the window
A determination unit that the reference window that, based on the determination of the determination means, from <br/> inverse quantization result by the first inverse quantization means, is referred to the reference window c
Copy the higher frequency band spectrum data of the referenced window is Indou, the ginseng spectral data copied
Second dequantizing means for outputting in association with the illumination window
And the predetermined value output by the first dequantization means.
A higher frequency band spectrum data value, the reference Win
The value of the high frequency band spectrum data of the dough is associated with the second dequantization means and output by the referenced wave.
After replacing it with the value of the high frequency band spectrum data of the window , it is inversely transformed and output as an acoustic signal on the time axis.
And means of force.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0161

[Correction method] Change

[Correction content]

As a result, in the decoding apparatus of the present invention, at least one referenced window is included in one frame.
Enter the higher frequency band data window, based on it to determine the determination means, can be generated by copying to said reference windows, as compared with conventional rich high sound quality and more high-frequency portion There is an effect that various acoustic signals can be reproduced.

[Procedure Amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0162

[Correction method] Change

[Correction content]

According to the encoding device of the present invention, the sharing determination means determines whether or not the spectra of the windows are similar to each other within a range satisfying a predetermined determination criterion,
The replacement means is arranged such that the spectrum between the windows is
When similar in the range, the high frequency range of other windows
For each sharing window that shares the story,
Replace the spectral data in the lower band of the window with a predetermined value.

[Procedure Amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0163

[Correction method] Change

[Correction content]

Therefore, when the spectra of the windows are similar to each other within a range satisfying a predetermined criterion, the spectrum data of the low band in addition to the high band is replaced with a predetermined value. For example, "0"
It is possible to simplify the processing of quantization and coding of that portion, and it is possible to significantly reduce the amount of encoded data of the acoustic signal up to the low frequency portion.

[Procedure Amendment 15]

[Document name to be amended] Statement

[Name of item to be corrected] 0164

[Correction method] Change

[Correction content]

Correspondingly, in the decoding device of the present invention, the judging means determines that the values of all spectrum data in each of the windows output by the first dequantizing means are predetermined values. , The window is determined to be the reference window , and the second dequantizer
The stage , based on the determination by the determining means , determines the predetermined referenced wave from the dequantization result of the first dequantizing means.
All spectral data including the low-frequency part of the window are copied, and the copied spectral data is used for the reference window.
Output in association with the dough , the acoustic signal output means,
The values of all the spectrum data in the reference window are associated with the second dequantization means and output by the output target.
After substituting with the values of the spectral data in the reference window ,
Inverse conversion is performed and output as an acoustic signal on the time axis.

[Procedure Amendment 16]

[Document name to be amended] Statement

[Name of item to be corrected] 0165

[Correction method] Change

[Correction content]

Therefore, according to the decoding apparatus of the present invention, 1
By inputting the whole area data for at least one referenced window for each frame and copying it to the reference window based on the judgment of the judging means.
Since it is generated , the low-frequency part has some error depending on the range of the predetermined criterion compared to the conventional one, but the higher-frequency part is higher based on the high-frequency part data input for at least one window per frame. There is an effect that it is possible to reproduce a high-quality sound signal with a rich range.

[Procedure Amendment 17]

[Document name to be amended] Statement

[Name of item to be corrected] 0166

[Correction method] Change

[Correction content]

Furthermore, the encoding apparatus of the present invention further comprises:
Of the spectral data input before Symbol first quantization means, the result of the quantization by the first quantization means, quantization result a spectral data close to the peak of the spectrum
Comprising a second quantizing means for re-quantizing, and a second encoding means for encoding the quantized result of the second quantizing means but with a predetermined normalization coefficient that becomes definite place, the the output means outputs the data encoded by said first encoding means and data encoded by the second encoding means.

[Procedure 18]

[Document name to be amended] Statement

[Correction target item name] 0167

[Correction method] Change

[Correction content]

Therefore, according to the encoding device of the present invention, the second quantizing means has the first quantizing means in which the quantizing result of the spectrum data close to the peak of the spectrum has a predetermined value continuously. Since the thing is re-quantized using a predetermined normalization coefficient, the quantization result of the spectrum data adjacent to the peak can be re-quantized to a value which is not continuous at a predetermined value. That is, there is an effect that the quantization error of the spectrum data adjacent to the peak can be corrected by the quantization of the second quantization means.

[Procedure Amendment 19]

[Document name to be amended] Statement

[Name of item to be corrected] 0168

[Correction method] Change

[Correction content]

In response to this, the decoding apparatus of the present invention is
Furthermore, from the second area in the input coded data ,
Regarding the same spectrum data, the first encoded data is
Second code quantized using different predetermined normalization coefficient
A second coded data separating means for separating data, before Symbol
Second decoding means for decoding the second encoded data ;
The decoding result by the first decoding means is monitored and the decoding is performed.
Specify the part that has a predetermined value continuously in the conversion result and specify
The decoding result by said second decoding means corresponding to the portion, and inverse quantized using said predetermined normalization factor, double
Second dequantization means for generating a number of spectral data ;
Of the spectral data outputted by the pre-Symbol first inverse quantization means, the values of the spectral data of the identified portion, was replaced by the value of the spectral data generated by said second inverse quantization means, inverse And an audio signal output means for converting and outputting as an audio signal on the time axis.

[Procedure amendment 20]

[Document name to be amended] Statement

[Name of item to be corrected] 0169

[Correction method] Change

[Correction content]

Therefore, according to the decoding apparatus of the present invention, since the second dequantization means is close to the spectrum data having the peak in each band, the quantization result by the first quantization means has a predetermined value. Since the generated continuous spectrum data is generated , the quantization error of the spectrum data near the peak can be corrected by the quantization of the second quantization means. As a result, there is an effect that the acoustic signal around the peak of the spectrum can be reproduced more faithfully to the original sound in the entire reproduction band of the acoustic signal.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mineo Tsushima             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Naoya Tanaka             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5D045 DA20                 5J064 AA00 BA09 BA16 BB12 BC02                       BC14 BC16 BC17 BC18 BC29                       BD02 BD03

Claims (41)

[Claims] 1. An encoding device for encoding an input acoustic signal, wherein the input acoustic signal is cut out at constant time intervals and converted into a frequency spectrum, whereby a set of spectrum data is extracted every frame time. When a plurality of conversion means for generating a plurality of sets are compared with each other obtained by the conversion means, and the spectra of the pairs are similar to each other in a range satisfying a predetermined criterion, the high-frequency part of one pair Share determination means for determining that the other set of spectrum data is to be shared, and replacement means for replacing the high range spectrum data of the other set with a predetermined value for the other set determined to share the high range spectrum data. A first quantizing means for quantizing the spectral data of each set after the replacement processing by the replacing means; and a quantum by the first quantizing means. First to encode the results
An encoding apparatus comprising: an encoding unit; and an output unit that outputs the data encoded by the first encoding unit. 2. The encoding device further obtains an average value of spectrum data of the same frequency for the high band part of the one set and the other set, and sets each obtained average value as a spectrum value. Averaging means for substituting the one set of high frequency band spectral data with the spectral data for performing the replacement processing by the averaging means and the replacing means, and then the spectral data of each set. Is quantized. 3. The encoding apparatus further includes, for each of the sets, shared information generation means for generating shared information indicating a determination result by the sharing determination means, and second encoding for the generated shared information. The encoding means is provided, and the output means outputs the data encoded by the first encoding means and the data encoded by the second encoding means. The encoding device according to claim 2. 4. The sharing determination means determines an energy difference between spectra in each of the sets, and determines that the energy is shared when the calculated energy difference is less than a predetermined threshold value. The encoding device according to any one of 3 above. 5. The sharing determination means compares frequency positions of spectrum data having peaks in each of the sets, and determines sharing based on the comparison result. The encoding device according to item 1. 6. The sharing determination means converts the spectrum data in each set using a predetermined function, compares the obtained conversion results, and determines to share based on the comparison result. The encoding device according to any one of claims 1 to 3, which is characterized. 7. The encoding device further comprises auxiliary information generating means for generating auxiliary information representing a characteristic of spectral data in a high frequency part of the spectrum data in each of the one set. 2 encoding means, in addition to the shared information,
The generated auxiliary information is coded, the replacement unit replaces the shared high frequency band spectrum data of each of the one set with a predetermined value, and the output unit is coded by the first coding unit. The encoded device according to any one of claims 3 to 6, wherein the encoded data and the data encoded by the second encoding means are output. 8. The auxiliary information generating means has a normal value that a value obtained by quantizing the spectrum data that becomes a peak in each band of a high frequency band of the spectrum data divided into a plurality of frequency bands is a constant value. Calculate the conversion factor,
The encoding device according to claim 7, wherein the calculated normalization coefficient is generated as the auxiliary information. 9. The auxiliary information generating means uses, for the spectral data divided into a plurality of bands, spectral data having a peak in each band of a high frequency band by using a normalization coefficient common to each band. 8. The encoding device according to claim 7, wherein the quantization is performed and a result of the quantization is generated as the auxiliary information. 10. The auxiliary information generating means generates, as the auxiliary information, the frequency position of the spectrum data having a peak in each band of the high frequency band of the spectrum data divided into a plurality of bands. The encoding device according to claim 7. 11. The spectrum data is an MDCT coefficient, and the auxiliary information generating means, for the spectrum data divided into a plurality of bands, gives a sign indicating whether the spectrum data is positive or negative at a predetermined frequency position in a high frequency band. The data is generated as the auxiliary information.
Encoding device described. 12. The auxiliary information generating means specifies, for each of the high frequency bands of the spectrum data divided into a plurality of bands, a low frequency band spectrum that is closest to the spectrum in the corresponding band. The encoding device according to claim 7, wherein is generated as the auxiliary information. 13. The encoding apparatus according to claim 12, wherein the information for specifying the low-frequency band spectrum is a number for specifying the band of the specified low-frequency spectrum. 14. The auxiliary information generating means adds a predetermined coefficient representing an amplification ratio of the amplitude of the high frequency band spectrum to the auxiliary information.
The encoding device according to any one of 1 to 13. 15. The output means further converts the data coded by the first coding means into a coded audio stream defined in a predetermined format, and at the same time, in an area within the coded audio stream. The stream output unit for storing and outputting the data encoded by the second encoding unit is provided in an area of which the use is not restricted by the encoding protocol. The encoding device according to any one of claims. 16. The stream output unit further includes an identification information addition unit that adds identification information indicating that the data has been encoded by the second encoding unit to the data encoded by the second encoding unit. 16. The encoding device according to claim 15, wherein the stream output unit stores the data to which the identification information is added in the area where use is not restricted by an encoding rule. 17. The output means further converts the data encoded by the first encoding means into an encoded audio stream defined in a predetermined format, and encodes by the second encoding means. The encoding device according to any one of claims 3 to 14, further comprising: a second stream output unit that stores the generated data in a stream different from the encoded acoustic stream and outputs the stream. 18. The sharing determination means, when the spectra of the pairs are similar to each other in a range satisfying a predetermined determination criterion, in addition to the high-frequency portion of the one pair, the spectrum data of a low-frequency portion, It is determined to be shared in the other set, the replacement means, for the other set determined to share the spectrum data, in addition to the high band part of the set to be input, further spectral data of the low band part is a predetermined value. The encoding device according to claim 1 or any one of claims 3 to 17, characterized in that. 19. An encoding device for encoding an input acoustic signal, comprising: converting means for extracting the input acoustic signal at regular time intervals and converting it into a frequency spectrum; and spectrum data obtained by the converting means. A first quantizing means for quantizing, and, out of the spectrum data input to the first quantizing means, the result of quantization by the first quantizing means is spectrum data close to the peak of the spectrum Second quantizing means for requantizing a value of which is a predetermined value using a predetermined normalizing coefficient; first coding means for coding the quantization result of the first quantizing means; Second encoding means for encoding the quantization result of the quantizing means, data encoded by the first encoding means, and data encoded by the second encoding means are output. An encoding device comprising: 20. The second quantizing means transforms the requantized quantization result using a predetermined function so that a smaller data amount can be obtained when encoded. Encoding device described. 21. The first quantizing means quantizes the spectrum data for each frequency band, and the second quantizing means does not quantize the spectrum data having a peak in each band, and a predetermined value is used. 21. The encoding device according to claim 19, wherein the encoding device is represented. 22. The second quantization means further comprises a normalization coefficient adjustment unit for further adjusting the normalization coefficient so that the quantization result of the second quantization means has a predetermined number of bits, and the second quantization means 22. The encoding apparatus according to claim 21, wherein the quantization means re-quantizes using the adjusted normalization coefficient and outputs the normalization coefficient together with the quantization result. 23. A decoding device for inputting encoded data encoded by the encoding device according to claim 1 and decoding the input encoded data, wherein the first encoded data in the input encoded data is the first encoded data. First decoding means for decoding the data coded by the coding means, and first dequantization means for dequantizing the decoding result of the first decoding means and outputting the spectrum data of each set. Monitoring the dequantization result of the first dequantization means, and when the value of the high frequency band spectrum data output by the first dequantization means is a predetermined value, the set is set to the other one. Determination means for determining a pair, and based on the determination of the determination means, from the dequantization result of the first dequantization means, the spectral data representing the high-frequency part of the one set is copied and copied. Spectral data on the other side A second dequantization unit that outputs the high-band part spectrum data that is output by the first dequantization unit and that is associated with the second dequantization unit. After replacing the value of the high frequency band spectrum data with the value of the high frequency band spectrum data output by the second dequantization means, inverse conversion is performed and an acoustic signal output means for outputting as an acoustic signal on the time axis is provided. A decoding device comprising. 24. A decoding device for inputting the encoded data encoded by the encoding device according to claim 3 and decoding the input encoded data, wherein the encoded data is encoded from the input encoded data. Coded data separation means for separating the shared information, first decoding means for decoding the data coded by the first coding means in the input coded data, and decoding of the first decoding means A first dequantization means for dequantizing the quantization result and outputting the spectrum data of each set, and a second decoding means for decoding the shared information separated from the input coded data, and Based on the shared information, the spectrum data representing the high band part of the one set is copied from the dequantization result of the first dequantization unit, and the copied spectrum data is output in association with the other set. Do 2 dequantization means, and the highband spectrum data output by the first dequantization means, the values of a set of highband spectrum data associated by the second dequantization means, Decoding, comprising: an acoustic signal output unit that substitutes the value of the high frequency band spectrum data output by the second dequantization unit, performs inverse conversion, and outputs as an acoustic signal on the time axis. apparatus. 25. A decoding device for inputting the encoded data encoded by the encoding device according to claim 7 and decoding the input encoded data, wherein the encoded data is encoded from the input encoded data. An encoded data separating unit that separates the shared information and the auxiliary information; a first decoding unit that decodes the data encoded by the first encoding unit in the input encoded data; First dequantizing means for dequantizing the decoding result of the decoding means and outputting the spectrum data of each set; and second decoding means for decoding the shared information and the auxiliary information that have been encoded. And, based on the decoded shared information and the auxiliary information, restore the spectrum data representing the high band part of the one set, and output the restored spectrum data in association with the other set. 2 inverse quantization And the values of the high band spectral data of the set, which is the high band spectral data output by the first dequantizing means and is associated by the second dequantizing means, with the second inverse. A decoding device, comprising: an acoustic signal output means for performing inverse transformation after replacing with a value of the high frequency band spectrum data output by the quantizing means, and outputting as an acoustic signal on a time axis. 26. A decoding device, which receives the encoded data encoded by the encoding device according to claim 8 and decodes the input encoded data, wherein the second dequantizing means comprises: Using the normalized coefficient in the decoded auxiliary information, the quantization value that is a predetermined value that is common to each band of the high frequency band and that corresponds to the predetermined spectrum data in each band is dequantized. 26. The decoding apparatus according to claim 25, wherein the high frequency band spectrum data is generated so that the spectrum data as a result of the dequantization has a peak in each band. 27. A decoding device for inputting the encoded data encoded by the encoding device according to claim 9, and decoding the input encoded data, wherein the second dequantizing means is The quantized value in the decoded auxiliary information is inversely quantized using a normalization coefficient that is a predetermined value that is common in each band of the high frequency band, and the spectrum data of the inversely quantized result is each band. 26. The decoding device according to claim 25, wherein the high frequency band spectrum data is generated so that it has a peak at. 28. A decoding device for inputting the encoded data encoded by the encoding device according to claim 10 and decoding the input encoded data, wherein the second dequantization means is 26. The decoding device according to claim 25, wherein the high frequency band spectrum data is generated such that the frequency position in the decoded auxiliary information has a peak in each band of the high frequency band. 29. A decoding device for inputting the encoded data encoded by the encoding device according to claim 11, and decoding the input encoded data, wherein the second dequantization means is 26. The decoding device according to claim 25, wherein the spectrum data at a predetermined frequency position in the high frequency band generates high frequency band spectrum data having the code in the generated auxiliary information. 30. A decoding device for inputting the encoded data encoded by the encoding device according to claim 12, and decoding the input encoded data, wherein the second dequantization means is , In each band of the high frequency band, the low frequency band spectrum data specified by the decoded auxiliary information is copied from the low frequency band spectrum data output by the first dequantization means, 26. The decoding device according to claim 25, which outputs the spectrum data of the region. 31. A decoding device for inputting a coded audio stream defined in a predetermined format from the coding device according to claim 16, and decoding the input coded audio stream. The encoded data separation means extracts data from an area of which the use is not restricted by the encoding convention in the input encoded audio stream, and the first decoding means extracts the data from the input encoded acoustic stream by the first code. Decoding the data encoded by the encoding means, the second decoding means analyzing the extracted data, and identifying in the data that the data has been encoded by the second encoding means. The decoding apparatus according to claim 24, wherein when the information is included, the shared information is decoded from the extracted data excluding the identification information. 32. A decoding device for inputting the encoded data encoded by the encoding device according to claim 18 and decoding the input encoded data, wherein the first encoded data in the input encoded data is the first encoded data. First decoding means for decoding the data coded by the coding means, and first dequantization means for dequantizing the decoding result of the first decoding means and outputting the spectrum data of each set. Monitoring the dequantization result of the first dequantization means, and when the value of all spectrum data output by the first dequantization means is a predetermined value, the set is set to the other set. Based on the determination means for determining that there is, the total spectrum data of the one set from the inverse quantization result of the first inverse quantization means, the copied spectrum data of the other Compatible with groups The second dequantization means for outputting and the spectrum data output by the first dequantization means, the values of all the spectrum data of the set associated by the second dequantization means A decoding device, comprising: an acoustic signal output unit that substitutes the value of the spectrum data output by the second inverse quantization unit, and then inversely transforms and outputs as an acoustic signal on a time axis. 33. A decoding device for inputting coded data coded by the coding device according to claim 18, and decoding the input coded data, the coded data being coded from the input coded data. Coded data separation means for separating the shared information, first decoding means for decoding the data coded by the first coding means in the input coded data, and decoding of the first decoding means A first dequantization means for dequantizing the quantization result and outputting the spectrum data of each set, and a second decoding means for decoding the shared information separated from the input coded data, and A second inverse that copies all the spectrum data of the one set from the dequantization result of the first dequantization unit based on the shared information and outputs the copied spectrum data in association with the other set. amount Quantization means and the spectrum data output by the first dequantization means, and the values of all the spectrum data of the set associated by the second dequantization means are converted by the second dequantization means. A decoding device comprising: an acoustic signal output means for performing inverse conversion after replacing the output spectrum data value and outputting as an acoustic signal on a time axis. 34. A decoding device for inputting the encoded data encoded by the encoding device according to claim 19 and decoding the input encoded data, wherein the second encoded data is converted into the second encoded data from the input encoded data. Coded data separation means for separating the data coded by the coding means; first decoding means for decoding the data coded by the first coding means in the input coded data; The first dequantizing means for dequantizing the decoding result of the first decoding means and outputting the spectrum data of each band, and the second decoding for decoding the data encoded by the second encoding means Means, and the decoding result of the second decoding means is inversely quantized using a predetermined normalization coefficient, and is adjacent to the spectrum data having a peak in each band, so that the first quantization means Second dequantization means for restoring continuous spectrum data whose sub-result is a predetermined value, and one spectrum data before and after one spectrum data among the spectrum data output by the first dequantization means. After replacing the values of a plurality of spectrum data that are adjacent to each other and each of which continuously has a predetermined value with the value of the spectrum data restored by the second inverse quantization means,
A decoding device, comprising: an acoustic signal output unit that performs inverse conversion and outputs as an acoustic signal on a time axis. 35. A decoding device for inputting the encoded data encoded by the encoding device according to claim 20 and decoding the input encoded data, wherein the second encoded data is extracted from the input encoded data. Coded data separation means for separating the data coded by the coding means; first decoding means for decoding the data coded by the first coding means in the input coded data; The first dequantizing means for dequantizing the decoding result of the first decoding means and outputting the spectrum data of each band, and the second decoding for decoding the data encoded by the second encoding means Means and inversely transforming the decoding result of the second decoding means using a predetermined function, and then inverse quantizing using a predetermined normalization coefficient,
Second dequantization means for reconstructing continuous spectrum data whose quantization result by the first quantization means has a predetermined value, since the spectrum data is adjacent to the peak spectrum data in each band, and the first dequantization means Of the spectrum data output by the means, a plurality of spectrum data values that are adjacent before and after one spectrum data for each band, and that are all continuously predetermined values, are used as the second dequantization means. After substituting with the values of the spectral data restored by
A decoding device, comprising: an acoustic signal output unit that performs inverse conversion and outputs as an acoustic signal on a time axis. 36. A decoding device for inputting the encoded data encoded by the encoding device according to claim 22, and decoding the input encoded data, wherein the second encoded data is converted into the second encoded data from the input encoded data. Coded data separation means for separating the data coded by the coding means; first decoding means for decoding the data coded by the first coding means in the input coded data; The first dequantizing means for dequantizing the decoding result of the first decoding means and outputting the spectrum data of each band, and the second decoding for decoding the data encoded by the second encoding means Means for extracting the adjusted normalization coefficient and the quantization result by the second quantization means from the decoding result of the second decoding means, and using the extracted quantization result by using the predetermined function. Reverse conversion In addition, since it is dequantized by using the extracted normalization coefficient and is adjacent to the spectrum data that has a peak in each band, continuous spectrum data in which the quantization result by the first quantization means has a predetermined value A second dequantization unit that restores, and among the spectrum data output by the first dequantization unit, adjacent to one spectrum data before and after each spectrum data for each band, and all of them are continuously predetermined values. After replacing the values of the plurality of spectrum data with the values of the spectrum data restored by the second inverse quantization means,
A decoding device, comprising: an acoustic signal output unit that performs inverse conversion and outputs as an acoustic signal on a time axis. 37. A program used in an encoding device for encoding an input acoustic signal, the program causing a computer to function as each unit included in the encoding device according to claim 1. . 38. A program used in a decoding device for inputting encoded data encoded by an encoding device and decoding the input encoded data, comprising a computer. A program that causes each unit included in the decoding device according to item 1 to function. 39. A computer-readable recording medium recording the program according to claim 37. 40. A computer-readable recording medium in which the program according to claim 38 is recorded. 41. An acoustic data distribution system for distributing acoustic data compressed and encoded into a low bit rate bit stream through a recording medium or a transmission medium, wherein the acoustic data distribution system comprises: An audio data distribution system comprising the encoding device according to any one of 18 to 20 and 22 and the decoding device according to any one of claims 23 to 36.