JP2003308096A - Method and device for converting data, method and device for reproducing data, method and device for restoring data, data format, recording medium and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent silent reproduction of data which can be only partially listened to on trial. <P>SOLUTION: When the value of normalization coefficient information of quantization units (13) to (16) higher than a listening band on trial is changed to zero, spectrum coefficient information of a band side higher than a position shown by Ad in Figure corresponding to the quantization units (13) to (16) is not referred to in reproducing listening data on trail, and therefore control information for distinguishing a frame for inhibiting trial listening from a frame for allowing trail listening is inserted into this range. A reproducing device for reproducing the listening data on trial refers to the control information and performs normal reproduction processing when the trial listening is allowed, and starts processing for the next a listening frame on trial without performing reproduction processing when the trial listening is not allowed. It is therefore possible to prevent silent reproduction even when there is a reproduction inhibition area to be silently reproduced before and after a listening area on trial. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data conversion method and a data conversion device, a data reproduction method and a data reproduction device, a data restoration method and a data restoration device, a data format, a recording medium, and a program, and in particular, a content audition A data conversion method and a data conversion device, a data reproduction method and a data reproduction device, a data restoration method and a data restoration device, a data format, a recording medium suitable for use when distributing data to users.
And about the program.

[0002]

2. Description of the Related Art For example, due to the spread of communication network technology such as the Internet, the improvement of information compression technology, and the higher integration or higher density of information recording media, audio, still images, and moving images have been developed. , Or
A sales form has been implemented in which digital contents composed of various multimedia data such as movies including audio and moving images are distributed to viewers through a communication network for a fee.

For example, CD (Compact Disk) and MD (Mi
ni-Disk) (trademark) or the like, that is, a store that sells a recording medium in which digital contents are recorded in advance, for example, a so-called MM in which a large number of digital contents such as music data are accumulated.
By installing an information terminal such as K (Multi Media KIOSK), not only can you sell packaged media,
It is possible to sell digital content.

The user inserts a recording medium such as an MD, which he / she has brought into the MMK, refers to a menu screen or the like, selects the title of the digital content to be purchased, and pays for the required content. The payment method is
It may be cash input, electronic money exchange, or electronic payment using a credit card or a prepaid card. The MMK records the selected digital content data on the recording medium inserted by the user by a predetermined process.

As described above, the seller of the digital contents uses the MMK to sell the digital contents to the user, and also, for example, via the Internet.
It is also possible to deliver digital content to users.

As described above, by not only selling the packaged media in which the contents are recorded in advance but also selling the digital contents themselves, the contents are distributed more effectively.

In order to distribute digital contents while protecting copyright, for example, Japanese Patent Laid-Open No. 2001-10
By using a technology such as 3047 or Japanese Patent Laid-Open No. 2001-325460, the content other than the auditionable part of the digital content is encrypted and distributed, and only the user who purchases the decryption key for the encryption is allowed to audition all the content. You can As an encryption method, for example, an initial value of a random number sequence that is a key signal for a bit string of PCM (Pulse Code Modulation) digital audio data is given, and a generated 0/1 random number sequence and PCM data to be distributed. A method is known in which the exclusive OR is used as an encrypted bit string. The digital content encrypted in this way is, for example, the above-mentioned MMK.
It is distributed to users by being recorded on a recording medium using, for example, or distributed via a network. The user who obtains the encrypted digital content data can listen to only the unencrypted auditionable part without playing the key, and plays back the encrypted part without decrypting it. Even so, I can only listen to noise.

Further, techniques for compressing audio data or the like for broadcasting, distributing via a network, and recording the compressed data on various forms of recording media such as magneto-optical discs have been improved. ing.

There are various methods for high-efficiency coding of voice data. For example, band division coding (for dividing an audio signal on the time axis into a plurality of frequency bands for coding without blocking the audio signal) SBC (Sub Band Coding) or spectrum conversion of signals on the time axis into signals on the frequency axis,
There is a blocking frequency band division method (so-called transform coding) in which a plurality of frequency bands are divided and each band is coded. Also, after performing band division by band division encoding,
A method is also considered in which a signal is spectrum-converted into a signal on the frequency axis in each band and coding is performed for each spectrum-converted band.

The filter used here is, for example,
There is a QMF (Quadrature Mirror Filter). Regarding QMF, "Digital coding of RE Crochiere"
speech in subbands "(Bell Syst. Tech. J. Vol.55, N
o.8 1974). Also Joseph H.
"Polyphase Quadrature Fitters-Anew by Rothweiler
References such as "subband coding technique" (ICASSP 83, BOSTON) describe filter division techniques of equal bandwidth.

Further, as the above-mentioned spectrum conversion,
For example, an input audio signal is divided into blocks in a predetermined unit time (frame), and a discrete Fourier transform (DFT: Discrete Fourier Transform), a discrete cosine transform (DCT: Discrete Cosine Transform),
Modified DCT transformation (MDCT; modified Discret)
e Cosine Transform) and so on. For example,
For more information about MDCT, JP Princen, AB Bra
dley (Univ. of Surrey Royal Melbourne Inst. of Tec
h.) et al., "Subband / Transform Cording Using Fil
ter Bank Designs Based on Time Domain Aliasing Can
cellation "(ICASSP 1987).

When the above-mentioned DFT or DCT is used as a method for spectrally converting the waveform signal, M
If the transformation is performed on a time block of samples, M
Independent real data are obtained. In order to reduce the connection distortion between the time blocks, it is normally N / 2 blocks each on both sides, that is, N on both sides.
Since the samples overlap, DFT and D
In CT, on average, independent M real number data are quantized and coded for (M + N) samples.

On the other hand, when the above-mentioned MDCT is used as a method of spectrum conversion, when conversion is performed with a time block consisting of M samples, both adjacent blocks are M / 2, respectively. In other words, from 2M samples that were overlapped M on both sides,
Since M independent real number data are obtained, in MDCT, on average, M real number data are quantized and coded for M samples.

In the decoding device, a waveform signal can be reconstructed by adding waveform elements obtained by inversely transforming each block from a code obtained by using MDCT while interfering with each other. it can.

Generally, by lengthening the time block for conversion, the frequency resolution of the spectrum is improved, and the energy is concentrated on a specific spectral component. Therefore, by using the MDCT in which the number of spectral signals obtained does not increase with respect to the number of underlying time samples, conversion is performed with a long block length by overlapping the adjacent blocks by half. By performing the conversion, compared to the case of using DFT or DCT for the conversion,
Encoding can be performed efficiently. Further, by providing a sufficiently long overlap between adjacent blocks, it is possible to reduce the inter-block distortion of the waveform signal.

As described above, the band in which the quantization noise is generated can be controlled by quantizing the signal divided into each band by filtering or spectrum conversion, and the characteristics such as masking effect can be used. Thus, it is possible to perceptually perform more efficient encoding. Also,
By performing normalization for each band, for example, with the maximum absolute value of the signal component in the band before performing the quantization, more efficient encoding can be performed.

When quantizing each frequency component divided into frequency bands, for example, the frequency division width may be determined in consideration of human auditory characteristics. That is, the audio signal may be divided into a plurality of bands (for example, 25 bands) so that the higher the band, which is generally called a critical band, becomes, the wider the bandwidth becomes.

Further, when the band is divided so that the critical band becomes wide, when the data for each band is encoded, a predetermined bit allocation may be performed for each band, or the band may be allocated. Bits may be adaptively allocated (bit allocation is performed) every time.

For example, when coefficient data obtained by MDCT is encoded by bit allocation, MD for each band obtained by MDCT for each block
The number of bits is adaptively assigned to each of the CT coefficient data and coding is performed. As the bit allocation method, for example, the following two methods are known.

R. Zelinski, P. Noll et al., "Adaptiv
e Transform Coding of Speech Signals "(IEEE Transa
ctions of Acoustics, Speech, and Signal Processin
g, Vol. ASSP-25, No. 4, August 1977)
It is described that the bit allocation is performed based on the signal size of each band. According to this method, the quantization noise spectrum is flattened and the noise energy is minimized. However, when considered auditorily, the masking effect is not used, so it is optimal in reducing the noise actually heard by the human ear. is not.

In addition, MA Kransner (Massachusetts In
Institute of Technology), "The critical band
coder digital encoding of the perceptual requirem
The paper "ents of the auditory system" (ICASSP 1980) describes a technique of using auditory masking to obtain a necessary signal-to-noise ratio for each band and perform fixed bit allocation. However, with this technique,
Even when the characteristic is measured with a sine wave input, the characteristic value is not so good because the bit allocation is fixed.

In order to solve these problems, all bits that can be used for bit allocation are allocated by a fixed bit allocation pattern that is predetermined for each small block, and bit allocation that depends on the signal size of each block. It is divided into two parts, and the division ratio depends on the signal related to the input signal. The smoother the spectrum of the signal, the larger the division ratio to the fixed bit allocation pattern. An efficient coding device has been proposed.

By using this method, when energy is concentrated on a specific spectrum like a sine wave input, a large number of bits can be allocated to a block including the spectrum, so that the overall signal The noise resistance characteristic can be significantly improved. In general, human hearing for a signal having a steep spectrum component is extremely sensitive. Therefore, improving the signal-to-noise characteristic by using such a method is not limited to the characteristic value in measurement but also human. Is effective in improving the quality of the sound actually heard.

As the bit allocation method, many methods other than the above have been proposed. Furthermore, since the model related to hearing is refined and the performance of the coding device is improved, it is possible to perform not only the characteristic values in measurement but also the human hearing with higher efficiency. There is. In these methods, a real number bit allocation reference value that achieves the signal-to-noise characteristics obtained by calculation as faithfully as possible is obtained, and an integer value approximating it is obtained and set as the number of assigned bits. It is generally done.

[0025] Further, Japanese Patent Application No.
-152865, or WO94 / 28633,
A method of separating a tonal component, which is particularly important for hearing, that is, a component in which energy is concentrated around a specific frequency, from the generated spectral signal and encoding the separated spectral component separately from other spectral components. Is described.
According to this method, it is possible to effectively encode an audio signal or the like at a high compression rate with almost no perceptible deterioration in hearing.

When an actual code string is generated, first, the quantization precision information and the normalization coefficient information are encoded with a predetermined number of bits for each band in which normalization and quantization are performed.
The normalized and quantized spectral signal is then encoded. In addition, ISO / IEC11172-3; (1993 (E), a
933) describes a high-efficiency coding method in which the number of bits representing the quantization accuracy information is set to differ depending on the band, and the number of bits representing the quantization accuracy information increases as the band becomes higher. Is standardized so that

There is also known a method of determining the quantization accuracy information from the normalization coefficient information in the decoding device, instead of directly encoding the quantization accuracy information. Then, since the relationship between the normalization coefficient information and the quantization accuracy information is determined, in the future, it becomes impossible to introduce a control using the quantization accuracy based on a more advanced auditory model. Also,
If the compression rate to be realized has a range, it becomes necessary to determine the relationship between the normalization coefficient information and the quantization accuracy information for each compression rate.

As a method for more efficiently encoding the quantized spectrum signal, for example, DA Huffman's "A Method for Construction of Minimum Redundan" is used.
There is also known a method for efficiently performing coding using a variable length code described in the paper "cy Codes" (Proc. IRE, 40, p.1098, 1952).

A signal encoded by the method described above can be encrypted and distributed in the same manner as in the case of the PCM signal. When this scrambling method is used, the key signal is Those that are not available cannot reproduce the original signal. There is also a method of converting the PCM signal into a random signal and then encoding for compression instead of encrypting the encoded bit string. However, when this scrambling method is used, the key signal is If you don't have it, you can only play noise.

By distributing the trial listening data of the content data, the sale of the content data can be promoted. The sample listening data includes, for example, data reproduced with lower sound quality than the original data, data capable of reproducing a part of the original data (for example, only the rusty portion), and the like. The user can play back the audition data and, if he or she likes it, purchase a key to decrypt the encryption so that the original sound can be played back or a new recording medium on which the original sound data is recorded is newly added. Try to buy to.

However, in the above-described scrambling method, the entire data cannot be reproduced or all of them are reproduced as noise. Therefore, for example, a recording medium in which voice is recorded with relatively low sound quality is distributed as trial data. It was not possible to use it for the purpose. Even if the data scrambled by these methods is distributed to the user, the user cannot grasp the general outline of the data.

Further, according to the conventional method, when a high-efficiency coded signal is encrypted, a code string having a meaning is given to a reproducing apparatus which is generally widely used,
It was very difficult not to lower the compression efficiency. That is, as described above, when the code string generated by performing the high efficiency encoding is scrambled, even if the code string is reproduced without being descrambled, not only noise is generated but also scramble is generated. If the generated code string does not conform to the standard of the original high efficiency code, there is a possibility that the reproduction process cannot be executed at all.

On the contrary, when high-efficiency coding is performed after scrambling the PCM signal, for example, if the amount of information is cut off by utilizing the property of hearing, irreversible coding results. Therefore, even if such a high efficiency code is decoded, the scrambled signal of the PCM signal cannot be correctly reproduced. That is, such a signal makes it extremely difficult to perform descrambling correctly.

Therefore, a method has been selected in which the scrambling can be properly released even if the compression efficiency is reduced.

With respect to such a problem, the present inventors have
In Japanese Unexamined Patent Application Publication No. 10-135944, for example, of music data converted into a spectrum signal and encoded,
By distributing the data, in which only the code corresponding to the high band is encrypted, as the audition data, even the user who does not have the key can decrypt and reproduce the unencrypted narrow band signal. A possible audio coding scheme has been disclosed. In this method, the code on the high frequency side is encrypted, the bit allocation information on the high frequency side is replaced with dummy data, and the true bit allocation information on the high frequency side is reproduced by the decoder that performs the reproduction process. Information is recorded at a position where information is not read (ignored) during processing.

By adopting this method, the user receives the trial listening data and reproduces the trial listening data,
As a result of the trial listening, it becomes possible to purchase a key for decrypting the favorite trial listening data into the original data for a fee, correctly reproduce desired music and the like in all bands, and enjoy with high sound quality.

[0037]

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-1359
According to the technique disclosed in Japanese Patent Laid-Open No. 44, a user who does not have a key can decode only a narrow band signal of data distributed without charge. However, since its security depends only on encryption, if the code is decrypted, the user can play high-quality music without paying a fee. Data distributor (content provider)
Cannot legitimately collect fees.

Further, the content provider does not limit the quality of the preview data as a whole over the content, but limits the quality of a part of the content or only a few points to enable the audition, and the other parts. However, there are cases where you want to prevent audition even for data with limited quality.

For example, when distributing the preview data free of charge, if the user wants to allow the user to audition only the rusty part of the music for a few tens of seconds with the quality limited to be reproducible. It is necessary to make the audition non-listenable to a part other than the auditionable part, and it is desired to create the audition data that can reproduce the auditionable part without unnaturalness.

As described above, by using the technique of making the non-listening-disabled portion unlistenable, even if the data is reproduced, the corresponding portion (the portion other than the rust) is silenced. You can However, when decoding and playing back the sampled data in which only the rusted part is silenced and only the rusted part is played back with low quality, the decoding process is performed from the beginning of the data until the part that can be auditioned. Will be reproduced without sound, and until the decoding of the data of the portion that can be listened to is performed, no sound will be reproduced and output, which is unnatural.

The present invention has been made in view of such a situation, and in the case of distributing the preview data in which only one part of the content data can be reproduced with low sound quality and the other part cannot be reproduced, the reproduction is performed. It enables to generate the trial listening data in which only the feasible part is naturally reproduced and the header length of the trial listening data is not changed, and further, it is possible to restore such trial listening data to the original data. Is.

[0042]

According to the data conversion method of the present invention, the first data contained in the first data string is converted into the second data.
The first replacement step for replacing the
A second replacing step of replacing the third data included in the area different from the data of the above with the fourth data,
Using the data generated by the processing of the first replacement step and the processing of the second replacement step,
And the third data replaced with the fourth data by the process of the second replacement step as the reproduction data when the second data string is reproduced. The fourth data is the data recorded in the unused data recording area.
It is characterized in that the control information is referred to when reproducing the data string.

The data recording area in which the third data is recorded is data that is not used as reproduction data when the second data string is reproduced by replacing the first data with the second data. It can be a recording area.

The first data string and the second data string are
Each of the third data may be composed of a plurality of frames, and the third data may be recorded in each of the plurality of frames. The third data is replaced by the third replacement process. The acquired fourth data may be control information indicating whether or not the corresponding frame can be reproduced.

A second generation step of generating a third data string necessary for restoring the second data string generated by the processing of the first generation step into the first data string is further included. And the third data string generated by the processing of the second generation step has the first data replaced by the second data by the processing of the first replacement step and the second data string By the process of the replacing step, the fourth data and the replaced third data can be included.

The third data string generated by the process of the second generation step is the second data string included in the second data string.
It is possible to further include position information indicating the position of the data.

In the process of the first replacing step, the first
Replaces the second data having a lower reproduction quality when the second data string is reproduced than the first data included in the first data string than when the second data string is reproduced. Can be allowed to.

It is possible to further include a coding step for coding the input data, and in the processing of the first replacing step, the coded data coded by the processing of the coding step is added to the first step. It is possible to replace the first data with the second data as the data string of.

The first data may include a variable length code.

The first data may include normalization coefficient information of the encoding process by the encoding step.

The first data may include the quantization accuracy information of the coding process by the process of the coding step.

The first data may include information indicating the number of quantization units in the encoding process by the encoding step.

A frequency component conversion step of converting the input data into frequency components, and a frequency component converted by the processing of the frequency component conversion step are converted into a first signal composed of a tone component and a signal other than the first signal. It is possible to further include a separation step of separating into the second signal, and in the processing of the encoding step, different encoding processing is executed for the first signal and the second signal. be able to.

A frequency component conversion step of converting the input data into frequency components and an encoding step of encoding the data converted into frequency components by the processing of the frequency component conversion step may be further included. In the processing of the first replacement step, the coded data coded by the processing of the coding step can be used as the first data string and the first data can be replaced with the second data. The third data to be replaced with the fourth data by the process of the second replacing step may include the spectral coefficient information of the frequency component converted by the process of the frequency component converting step.

The first data can be data showing a predetermined numerical value, and the second data can be data obtained by minimizing the numerical value of the first data.

The second data can be obtained by replacing at least a part of the first data with random data.

The second data is the first data if it is decrypted.
The data length can be shorter than the data length when the data of 1 is decoded.

The fourth data may include at least a part of the first data replaced by the process of the first replacing step.

For the fourth data, when reproducing the second data string, at least part of the first data included in the fourth data is used to restore the second data. It is possible to further include information indicating whether or not is possible.

The data converting apparatus of the present invention includes the first replacing means for replacing the first data included in the first data string with the second data, and the first replacing means, which is included in a region different from the first data. Generating a second data string using the second replacement means for replacing the third data with the fourth data, the first replacement means, and the data generated by the second replacement means Means and a second
The third data to be replaced with the fourth data by the replacement means is data recorded in a data recording area that is not used as reproduction data when the second data string is reproduced, and the fourth data is , And is the control information referred to when the second data string is reproduced.

The program recorded on the first recording medium of the present invention comprises a first replacing step for replacing the first data included in the first data string with the second data, and a first replacing step. The third included in the area different from the data
Second replacing step for replacing the data of the above with the fourth data, the processing of the first replacing step, and the second
Generating step of generating a second data string using the data generated by the process of the replacing step of, and the third data replaced by the fourth data by the process of the second replacing step is The second data string is data recorded in a data recording area that is not used as reproduction data when reproduced, and the fourth data is control information referred to when reproducing the second data string. It is characterized by

A first program of the present invention includes a first replacing step for replacing the first data included in the first data string with the second data, and an area different from the first data. Using the second replacement step of replacing the stored third data with the fourth data, the processing of the first replacement step, and the data generated by the processing of the second replacement step, the second data A third data which includes a generation step of generating a column, and is replaced with the fourth data by the process of the second replacement step is a data recording area which is not used as reproduction data when the second data row is reproduced. The fourth data is control information referred to when reproducing the second data string.

The data reproducing method of the present invention includes a reproduction control step of controlling the reproduction of the second data string based on the control information contained in the second data string, and includes the first data string and the second data string. The data string is composed of a plurality of frames
The plurality of frames of the data string of <1> includes control information referred to when the reproduction of the second data string is controlled by the processing of the reproduction control step.

The control information can be information for designating whether or not the corresponding frame can be reproduced when the reproduction of the second data string is controlled by the processing of the reproduction control step. .

The second data string can be generated by replacing the first data included in the first data string with the second data, and the second data string can be generated by the processing of the reproduction control step. The reproduction quality when the reproduction of the data string is controlled may be inferior to when the reproduction of the first data string is performed.

The control information is used when the reproduction of the second data string is controlled by the process of the reproduction control step because the first data included in the first data string is replaced with the second data. It may be recorded in a data area that is no longer used as reproduction data.

The control information may include at least a part of the first data replaced by the second data.

As the control information, when the reproduction of the second data string is controlled by the processing of the reproduction control step, at least a part of the first data included in the control information is used for the second information. It may further include information indicating whether the data can be restored.

It is possible to further include a decoding step for decoding the second data string. In the processing of the reproduction control step, the second data decoded by the processing of the decoding step is included.
It is possible to control the reproduction of the data string of
The first data string may be an encoded data string.

The first data may include a variable length code.

The first data may include normalization coefficient information.

Quantization accuracy information can be included in the first data.

The first data may include the number of quantization units.

It is possible to further include an inverse transformation step of inversely transforming the frequency component and a decoding step of decoding the second data string inversely transformed by the processing of the inverse transformation step. In the processing, the reproduction of the second data string decoded by the processing of the decoding step can be controlled, and the first data string is a data string that has been converted into frequency components and encoded. And the first data may include spectral coefficient information.

The first data can be data indicating a predetermined numerical value, and the second data can be data in which the numerical value of the first data is minimized.

The second data can be obtained by replacing at least a part of the first data with random data.

The second data, when decoded by the processing of the decoding step, may have a shorter data length than the data length when the first data is decoded.

The data reproducing apparatus of the present invention comprises a reproducing means for reproducing the second data string based on the control information contained in the second data string, and the first data string and the second data string are , The plurality of frames of the second data string include control information referred to when the second data string is reproduced by the reproducing means.

The program recorded on the second recording medium of the present invention includes a reproduction control step for controlling the reproduction of the second data string based on the control information contained in the second data string. The first data string and the second data string are composed of a plurality of frames, and when the reproduction of the second data string is controlled in the plurality of frames of the second data string by the process of the reproduction control step. It is characterized in that control information to be referred to is included in each.

The second program of the present invention includes a reproduction control step for controlling reproduction of the second data string based on the control information contained in the second data string, and the first data string and the second data string. Of the second data string is composed of a plurality of frames, and the plurality of frames of the second data string are respectively provided with control information referred to when the reproduction of the second data string is controlled by the process of the reproduction control step. It is characterized by being included.

The data restoration method of the present invention comprises an acquisition control step for controlling the acquisition of the third data string including the information necessary for restoring the first data string to the second data string,
A restoring step of restoring the second data sequence based on the third data sequence whose acquisition is controlled by the process of the acquisition control step, wherein the third data sequence is for restoring the second data sequence. In the process of the restoring step, the first data included in the third data string whose acquisition is controlled by the process of the acquisition control step is included in the first data string. The second data string is restored by replacing it with the existing second data, and a part of the second data is control information that is referred to when reproducing the first data string. .

The first data string may be composed of a plurality of frames, the control information is included in each of the plurality of frames, and corresponds to the case where the first data string is reproduced. It may be information that specifies whether or not the frame can be reproduced.

The control information may include at least a part of the first data for replacing the second data, and in the process of the restoration step, the first data included in the control information may be included. It is possible to restore the second data string by further replacing the first data with the second data included in the first data string.

For the control information, when the second data string is restored by the processing of the restoration step, at least a part of the first data included in the control information is used for the second control data.
It is possible to further include information indicating whether or not the data of the above can be restored.

The first data sequence may be an encoded data sequence, and the first data may include a variable length code.

The third data string whose acquisition is controlled by the process of the acquisition control step may further include position information indicating the position of the first data that replaces the second data.

The second restored by the processing of the restoration step
It is possible to further include a recording control step of controlling recording of the data string of No. 1 to a predetermined recording medium.

The second restored by the process of the restore step
It is possible to further include a decoding step of decoding the data string of.

Second decoded by the processing of the decoding step
It is possible to further include a reproduction control step for controlling the reproduction of the data string of.

The first data sequence may be an encoded data sequence, and the first data may include normalization coefficient information.

The first data string can be an encoded data string, and the first data can include quantization accuracy information.

The first data sequence can be an encoded data sequence, and the first data can include the number of quantization units.

The first data sequence may be a data sequence converted into frequency components and coded,
Spectral coefficient information can be included in the first data.

The first data can be data showing a predetermined numerical value, and the second data can be data in which the numerical value of the first data is minimized.

The second data can be obtained by replacing at least a part of the first data with random data.

When the second data is decoded by the processing of the decoding step, the second data can have a shorter data length than the data length when the first data is decoded.

The data restoration device of the present invention obtains the third data sequence including the information necessary to restore the first data sequence into the second data sequence, and the acquisition device obtains the third data sequence. A restoring unit that restores the second data string based on the third data string, the third data string including the first data for restoring the second data string, and the restoring unit , The second data string is restored by replacing the first data included in the third data string acquired by the acquisition means with the second data included in the first data string. , Part of the second data is control information referred to when reproducing the first data string.

The program recorded on the third recording medium of the present invention controls the acquisition of the third data string including the information necessary for restoring the first data string to the second data string. An acquisition control step and a restoration step of restoring the second data string based on the third data string whose acquisition is controlled by the processing of the acquisition control step, wherein the third data string is the second data. In the process of the restoration step, the first data included in the third data sequence whose acquisition is controlled by the process of the acquisition control step is included in the first data for restoring the column. Second included in the row
The second data string is restored by replacing the first data string by replacing the first data string with the first data string, and a part of the second data string is control information that is referred to when the first data string is reproduced.

A third program of the present invention comprises an acquisition control step for controlling acquisition of a third data string including information necessary for restoring the first data string into the second data string, and an acquisition control step. And a restoring step of restoring the second data string based on the third data string whose acquisition is controlled by the process of step, wherein the third data string is a third data string for restoring the second data string. In the process of the restoration control step, the first data included in the third data string whose acquisition is controlled by the process of the acquisition control step
Of the second data string by replacing it with the second data included in the second data string, and a part of the second data is the control information referred to when the first data string is reproduced. Is characterized in that.

The data format of the present invention includes a plurality of frames which are set so that the reproduction quality is deteriorated as compared with the corresponding portion of the content data.
The control information used at the time of reproduction is recorded in the area not used as the reproduction data at the time of reproduction because the reproduction quality is set to be deteriorated compared to the content data. Is characterized by.

In the data conversion method, the data conversion device, and the first program of the present invention, the first data included in the first data string is replaced with the second data, and the first data Replaces the third data included in the different area with the fourth data, generates the second data string using the data generated by the replacement of the data, and replaces the third data with the fourth data. Three
Is the data recorded in the data recording area that is not used as reproduction data when the second data string is reproduced, and the fourth data is referred to when the second data string is reproduced. Control information.

In the data reproducing method, the data reproducing apparatus, and the second program of the present invention, the second data string is reproduced based on the control information contained in the second data string, and the first data string is reproduced. The second data string is composed of a plurality of frames, and the plurality of frames of the second data string include control information that is referred to when the second data string is reproduced.

In the data restoring method, the data restoring device, and the third program of the present invention, the third data string including the information necessary for restoring the first data string to the second data string is The second data string is recovered based on the acquired third data string, the third data string includes the first data for recovering the second data string, and the third data string By replacing the first data included in the first data string with the second data included in the first data string, the second data string is restored, and a part of the second data is replaced by the first data string. The control information is referred to when reproducing the data string.

In the data format of the present invention,
It contains multiple frames that are set to have a lower playback quality than the corresponding portion of the content data, and the frames are set to have a lower playback quality than the content data. The control information used at the time of reproduction is recorded in the area not used as the reproduction data.

[0105]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

Here, a digital signal such as an audio PCM signal is input and band division coding (SBC),
Adaptive Transform cordin (ATC)
g) and the case of performing high-efficiency coding by performing adaptive bit allocation. Adaptive transform coding is based on discrete cosine transform (DCT),
It is an encoding method that adapts the bit allocation, converts the input signal into a spectrum signal for each time block, and normalizes the spectrum signals collectively for each predetermined band, that is,
Each signal component is divided by a normalization coefficient that approximates the maximum signal component, and then the signal is quantized and encoded with a quantization precision timely determined by the property of the signal.

FIG. 1 is a block diagram showing an example of the configuration of an encoding apparatus 1 that receives an acoustic waveform signal and creates trial listening data.

The conversion unit 11 receives the input of the acoustic waveform signal, converts it into a signal frequency component, and outputs it to the signal component encoding unit 12. The signal component coding unit 12 codes the input signal frequency component and outputs the coded signal frequency component to the code string generation unit 13. The code string generation unit 13 generates a code string from the signal frequency components coded by the signal component coding unit 12, and outputs the code string to the audition data generation unit 14. The audition data generation unit 14 performs predetermined processing such as rewriting of the normalization coefficient information and insertion of control information on the code string input from the code string generation unit 13 to reproduce audio data with high sound quality. The (original data) is converted into trial listening data, and additional data (restoration data) corresponding to the trial listening data, which is sold to a user who desires to reproduce the original data, is generated and output.

FIG. 2 is a block diagram showing a more detailed structure of the conversion unit 11.

The acoustic waveform signal input to the conversion unit 11 is
It is divided into two bands by the band division filter 21,
The respective signals are output to the forward spectrum conversion units 22-1 and 22-2. The forward spectrum conversion units 22-1 and 22-2 convert the input signal into a spectrum signal component using, for example, MDCT, and output the spectrum signal component to the signal component encoding unit 12. The signals input to the forward spectrum conversion units 22-1 and 22-2 are the band division filter 2
The bandwidth of the signal input to 1 is 1/2, and the input of the signal is also thinned to 1/2.

In the conversion unit 11 of FIG. 2, the signal divided into two bands by the band division filter 21 is M
Although it has been described that the DCT is used to convert the spectrum signal component, any method may be used to convert the input signal into the spectrum signal component. MD without dividing
You may make it convert into a spectrum signal component using CT. Alternatively, the forward spectrum conversion units 22-1 and 22-2 may convert the input signal into a spectrum signal using DCT or DFT.

Although it is possible to divide an input signal into band components by using a so-called band division filter, MDCT, DCT capable of computing a large number of frequency components with a relatively small amount of computation. , Or D
It is preferable to perform spectrum conversion using FC.

In FIG. 2, the input acoustic waveform signal is explained as being divided into two bands by the band division filter 21, but the number of band divisions does not have to be two. Needless to say. Information indicating the number of band divisions in the band division filter 21 is output to the code string generation unit 13 via the signal component encoding unit 12.

FIG. 3 shows the MD obtained by the conversion unit 11.
It is the figure which converted into the power level the absolute value of the spectrum signal by CT, and was shown. The acoustic waveform signal input to the conversion unit 11 is converted into, for example, 64 spectrum signals for each predetermined time block. These spectral signals are processed by the signal component coding unit 12 by a process described later, for example, as shown by 16 frames surrounded by solid lines in the figure, 16 of [1] to [16] , And quantization and normalization are performed for each band. A set of spectrum signals divided into these 16 bands, that is, a set of spectrum signals to be quantized and normalized is a quantization unit.

By changing the quantization precision for each quantization unit based on the distribution of the frequency components, efficient encoding is possible which can minimize the deterioration of the quality of the sound heard by humans. Becomes

FIG. 4 is a block diagram showing a more detailed structure of the signal component coding unit 12. Here, the frequency component coding unit 12 separates a tone portion that is particularly important in terms of hearing from the input spectrum signal, that is, a signal component in which energy is concentrated around a specific frequency, and separates the other spectrum. A case where encoding is performed separately from the components will be described.

The spectrum signal input from the converting unit 11 is separated into a tone component and a non-tone component by the tone component separating unit 31, the tone component is output to the tone component encoding unit 32, and the non-tone component is , Is output to the non-tone component encoding unit 33.

The tone component and non-tone component will be described with reference to FIG. For example, when the spectrum signal input to the tone component separating unit 31 is a signal as shown in FIG. 5, a portion having a particularly high power level is separated from the non-tone component as the tone components 41 to 43. The position data P1 to P3 indicating the positions of the separated tone components 41 to 43 and the width of the frequency extracted as the tone component are respectively detected and output to the tone component encoding unit 32 together with the tone component. It

As the method of separating the tone component, for example, the method described in Japanese Patent Application No. 5-152865 or WO94 / 28633, which the present inventor previously applied, may be used. The tone component and the non-tone component separated by this method are quantized with different numbers of bits by the processing of the tone component encoding unit 32 and the non-tone component encoding unit 33, which will be described later.

The tone component coding unit 32 and the non-tone component coding unit 33 code the input signals, respectively. The tone component coding unit 32 determines the number of quantization bits for the tone component. Large, that is, quantization is performed with high quantization accuracy, and the non-tone component encoding unit 33
The non-tone component is quantized with a small number of quantization bits, that is, with low quantization accuracy.

Regarding each tone component, it is necessary to newly add position information of the tone component and information such as the width of the frequency extracted as the tone component, but the spectrum signal of the non-tone component is quantized with a small number of bits. Can be converted. In particular, when the acoustic waveform signal input to the encoding device 1 is a signal in which energy is concentrated on a specific spectrum, by adopting such a method, almost no auditory deterioration is felt. In addition, it is possible to effectively encode with a high compression rate.

FIG. 6 is a block diagram showing a more detailed structure of the tone component encoder 32 of FIG.

The normalization section 51 receives the spectrum signal of the tone component for each quantization unit, normalizes it, and outputs it to the quantization section 52. Quantization accuracy determination unit 53
Calculates the quantization precision with reference to the input quantization unit, and outputs the calculation result to the quantization unit 52. Since the input quantization unit is a tone component, the quantization precision determination unit 53 calculates the quantization precision so that the quantization precision becomes high. The quantization unit 52 quantizes the normalization result input from the normalization unit 51 with the quantization accuracy determined by the quantization accuracy determination unit 53 to generate a code, and in addition to the generated code, , And outputs coding information such as normalization coefficient information and quantization accuracy information.

The tone component coding section 32 also stores the position information of the tone component input together with the tone component, etc.
It is encoded and output together with the tone component.

FIG. 7 is a block diagram of the non-tone component coding unit 33 of FIG.
3 is a block diagram showing a more detailed configuration of FIG.

The normalizing section 54 receives the input of the spectrum signal of the non-tone component for each quantization unit, normalizes it, and outputs it to the quantizing section 55. Quantization accuracy determination unit 56
Calculates the quantization precision with reference to the input quantization unit, and outputs the calculation result to the quantization unit 55. Since the input quantization unit is a non-tone component, the quantization precision determination unit 56 calculates the quantization precision so that the quantization precision becomes low. The quantization unit 55 quantizes the normalization result input from the normalization unit 54 with the quantization precision determined by the quantization precision determination unit 56 to generate a code, and in addition to the generated code, , And outputs coding information such as normalization coefficient information and quantization accuracy information.

It is possible to further improve the coding efficiency with respect to the above-mentioned coding method. For example, variable length coding is performed, and among the quantized spectrum signals, a relatively short code length is assigned to a high frequency one, and a relatively long code length is assigned to a low frequency one. By allocating, the coding efficiency can be further improved.

Then, the code string generator 13 of FIG. 1 records from the code of the signal frequency component output by the signal component encoder 12 to, for example, a recording medium or another data frequency via a data transmission path. A code string that can be sent to an information processing device,
That is, a code string composed of a plurality of frames is generated and output to the trial listening data generation unit 14. The code string generated by the code string generation unit 13 is audio data that can be reproduced with high sound quality by an ordinary decoder. FIG. 8 shows a frame format of audio data generated by the code string generation unit 13 and capable of being reproduced with high sound quality.

At the beginning of each frame, a fixed length header containing a sync signal is arranged. The header also records the number of band divisions of the band division filter 21 of the conversion unit 11 described with reference to FIG.

In each frame, following the header, tone component information regarding the separated tone component is recorded.
In the tone component information, the number of tone components, the tone width, and the quantization precision information of the quantization performed on the tone components by the tone component coding unit 32 described with reference to FIG. 6 are recorded. Then, as the data of the tone components 41 to 43, respective normalization coefficients, tone positions, and spectrum coefficients are recorded. Here, for example, the normalization coefficient of the tone component 41 is 30, the normalization coefficient of the tone component 42 is 27, and the normalization coefficient of the tone component 43 is 24.

Then, after the tone component information, non-tone component information is described. The non-tone component information includes the number of quantization units (16 in this case), and the quantization accuracy information of the quantization performed on the non-tone component by the tone component encoding unit 33 described with reference to FIG. Normalization coefficient information and spectrum coefficient information of each of the quantization units are recorded. In the normalized coefficient information, a value of 46 in the lowest quantization unit [1] to a value of 8 in the highest quantization unit [16] is recorded for each quantization unit. Here, as the normalization coefficient information,
It is assumed that a value proportional to the dB value of the power level of the spectrum signal is used. Further, when the length of the content frame is a fixed length, an empty area may be provided after the spectrum coefficient information.

FIG. 9 is a block diagram showing a more detailed configuration of the trial listening data generator 14 of FIG.

The trial-listening-data generation processing control unit 61 determines the trial-listening-area determining unit 62 based on setting data such as a trial-listening area of the trial-listening data and a trial-listening band of the trial-listening area, which is input from an external operation input unit (not shown). , And the band limitation processing unit 63
To control. The trial listening area is a portion of the trial listening data that can be reproduced with low quality without using additional data. For example, a rusty portion or the like is set as the trial listening area. A plurality of trial listening areas may be set in the trial listening data. The trial listening band in the trial listening region is a frequency band in which low quality reproduction is performed. For example, in FIG.
By designating only a part of the quantization units of the spectrum data described with reference to, it is possible to reproduce only a frequency band within a certain range and to reduce the quality of reproduced sound.

The audition area determination unit 62 controls the audition data generation processing controller 6 for each frame described with reference to FIG.
According to the control of No. 1, it is determined whether the input frame is within the audition area, and the determination result is the band limitation processing unit 6
3 and the control information insertion unit 64. According to the control of the trial-listening data generation processing control unit 61, the trial-listening region determination unit 62 sets the input frame sequence into a protected region, that is, a region where trial listening is not permitted and a trial listening region, for example. Distinguish.

The band limitation processing section 63 has a trial listening area judging section 6
Based on the signal input from 2, the input frame is
Data with a limited audition band is generated based on whether or not the frame is included in the audition area. Information about the trial listening band in the trial listening area is input from the trial listening data generation processing control unit 61.

For example, as the audition band of the auditionable part,
When the quantization unit [1] to the quantization unit [12] are designated, the band limitation processing unit 63, when the input frame is the frame of the trial listening area, as shown in FIG. Higher side quantization unit [1
3] to the value of the normalization coefficient information of the quantization unit [16] are, for example, minimized to be the normalization coefficient 0. Therefore, the quantization unit [13] to the quantization unit [1
6], a valid value is described in the spectrum coefficient information of the portion, but since the normalized coefficient information is 0 at the time of reproduction, the spectrum of the corresponding portion is not strictly 0. However, from the viewpoint of audibility, the value is substantially equal to 0. Therefore, the spectral coefficient information on the higher frequency side than the position indicated by Ad in the figure is synonymous with not being referred to.

Similarly to the non-tone component, the value of the normalization coefficient of the portion of the tone component that is out of the audition band is also minimized, for example, to 0 so that the spectrum signal of the corresponding tone component is reproduced. Is also minimized (substantially changed to a value equivalent to 0).

FIG. 12 shows a spectrum signal when the trial listening data shown in FIG. 11 is reproduced. Since the normalization coefficient information of the quantization unit [13] to the quantization unit [16] is changed to 0, the corresponding spectrum signal is minimized. Similarly, for the two tone components included in the quantization unit [13] to the quantization unit [16], the corresponding spectrum signal is also minimized. That is, when the sample data is decoded and played back,
In the auditionable portion, only the narrow band spectrum signal is reproduced.

By doing so, when the trial listening area of the trial listening data is played back, only narrow band data is played back, so that data of lower quality is played back as compared with the original data described with reference to FIG. It

Further, the band limitation processing section 63 sets the values of all the normalization coefficient information of the quantization units [1] to [16] of the frame corresponding to the non-listening portion to 0. By this, the data of the frame (protected area) that cannot be auditioned is
There is no sound even when played back.

The band limitation processing unit 63 uses the replacement data such that the decoded data length when the trial listening data is decoded is not longer than the decoded data length when the original data is decoded, Generate a preview frame.

The control information insertion unit 64 prevents unnatural reproduction such as suddenly flowing out of the trial listening portion after the silent state continues when the trial listening data is reproduced, Control information indicating whether reproduction is possible is inserted into all frames so that only the trial listening area is continuously reproduced. According to the information input from the trial listening area determination unit 62, the control information insertion unit 64 sets the control information to the area of the spectral coefficient information that is not referred to, that is, the area that is ignored when the trial listening data is played because the playback quality is limited. Is inserted and output to the audition data generation unit 66. Then, the control information inserting unit 64 adds the true spectrum coefficient information corresponding to the portion in which the control information is inserted, and, if necessary, the information indicating the position where the control information is inserted, to the additional frame generating unit 65. Output to.

FIG. 13 shows the frame format when the control information is inserted.

As described with reference to FIG. 11, when the value of the normalization coefficient information of the quantization unit [13] to the quantization unit [16] higher than the listening band is changed to 0, Quantization unit [13] to quantization unit [1
6], which is synonymous with not being referred to, is the spectrum coefficient information on the higher band side than the position indicated by Ad in the figure, and thus any control information can be described within this range.

Further, the control information insertion unit 64 writes random dummy data or the like at a position where control information is not described within the range of the spectrum coefficient information on the higher frequency side than the position indicated by Ad in the figure. May be. In this case, the control information insertion unit 64 adds the true spectrum coefficient information corresponding to the portion in which the dummy data is described, and, if necessary, the information indicating the position where the dummy data is inserted, to the additional frame generation unit 65. Output to.

Here, the control information is described as being inserted at the position corresponding to the spectral coefficient information that is not referred to when the trial listening data is reproduced. However, if the portion is not referred to when the trial listening data is reproduced, the control information is inserted. The position may be other than the position corresponding to the spectral coefficient information.

FIG. 14 shows an example of the format of control information.

As the control information, the playback device that receives the trial listening data and plays back the trial data determines whether the corresponding frame is a frame for which trial listening is permitted or a frame for which trial listening is not permitted. As information for doing so, a trial listening permission flag, a trial listening start flag, and a trial listening end flag are described.

The audition permission flag is set by a person who has the copyright of the content, and is for distinguishing the frame for prohibiting the audition from the frame for permitting the audition. In the playback device that plays back the trial listening data, the trial listening permission flag is referred to, and if the trial listening is permitted, normal playback processing is performed, and if the trial listening is not permitted, the next trial listening frame is performed without performing the playback processing. Start processing for.
As a result, the reproduction process is skipped for the frames for which previewing is prohibited, so that silent playback can be prevented even when there are frames that cannot be previewed before and after the previewing area.

The audition start flag and audition end flag are
This is information that is set in a trial listening frame within a predetermined time after the start position of the trial listening region and within a predetermined time before the end position of a group of trial listening regions.
If it is set to seconds, the audition start flag is set in the audition frame that is reproduced within 3 seconds from the start of the audition area so that it can be discriminated, and the audition frame that is reproduced within 3 seconds before the end of the audition area is included in the audition frame. The audition end flag is set so that it can be discriminated.

Thus, for example, when the trial listening data is played back by the playback apparatus, it is possible to perform playback processing such as fade-in and fade-out before and after the trial listening area. That is, when there are a plurality of audition areas, in the original original data, a plurality of audition areas that should be reproduced at different positions are continuously reproduced at the same volume, whereas in the original original data, a plurality of audition areas are reproduced. Since reproduction processing such as fade-in and fade-out can be performed before and after the trial listening area at each start and end, the trial listening data can be more comfortable for the user and can increase the purchase will. it can.

In particular, when the spectrum coefficient information is variable-length coded and the variable-length code is sequentially described in the area for describing the spectrum coefficient information from the low band side to the high band side, the spectrum not referred to Since the control information is described in the coefficient information area, a part of the variable length code in the middle frequency band is lost, so that the high frequency side data including the part cannot be decoded at all. That is, it becomes difficult to restore the spectral coefficient information related to the original data included in the trial listening data without using additional data, so that the safety of the trial listening data is enhanced.

As described above, when a part of the data such as the normalization coefficient is replaced with 0 or the control information, it is relatively short in key length to infer the true data for the replaced data. It is much more difficult than deciphering the encryption key. In addition, if the trial listening data is tampered with, it may rather deteriorate the sound quality. Therefore, it becomes very difficult for a user who is not permitted to audition the original data to guess the original data based on the audition data, and the rights of the author and distributor of the content data can be protected more firmly. It will be possible.

In addition, in the unlikely event that in some audition data,
Even if the true data for the replaced data is guessed, the damage will not spread to other contents, unlike the case where the encryption algorithm is decrypted, so encryption is performed using a specific algorithm. It is more secure than distributing the content data that has been subjected to as trial listening data.

In the above, the true normalization coefficient information and the true spectrum coefficient information replaced by the band limitation processing section 63 and the control information inserting section 64 are supplied to the additional frame generating section 65 described later and described in the additional frame. To be done. The band limitation processing unit 63, in addition to the normalization coefficient information,
For example, the values such as the quantization accuracy information and the number of quantization units may be changed to 0 or random dummy data, so that the additional frame generation unit 65 described later is changed by the band limitation processing unit 63. For example, the input of the information indicating the values such as the quantization accuracy information and the number of quantization units is received, and the information is described in the additional frame.

However, when changing the normalization coefficient information and when changing the quantization accuracy information, it is difficult to illegally infer the original data from the trial listening data without using additional data, that is, the trial listening. The safety strength of the data will be different. For example, when a bit allocation algorithm that calculates the quantization accuracy information based on the normalization coefficient information is used when the original data is generated, even if the value of only the quantization accuracy information is changed, the normalization coefficient There is a risk of using the information as a clue to infer the true quantization accuracy information.

On the other hand, even if only the normalization coefficient information is changed, it is difficult to infer the normalization coefficient information from the quantization accuracy information, so it can be said that the safety level of the audition data is high. By changing the values of both the normalization coefficient information and the quantization accuracy information, the risk of illegally guessing the original data is further reduced. Further, the value of the normalization coefficient information or the quantization accuracy information may be selectively changed according to the content frame of the trial listening data.

The additional frame generation unit 65, when the band is limited by the band limitation processing unit 63 and the user who auditioned the sampled data listens to the music with high sound quality based on the information on the changed normalization coefficient and the like, Generate additional frames that make up the additional data for restoring the original data you purchase.

FIG. 15 shows the format of the generated additional frame. As described with reference to FIG. 13, when the quantization unit [1] to the quantization unit [12] are selected as the audition band, in each frame of the audition data, the quantization unit [13] to the quantization unit The normalization factor for each of the tone and non-tone components corresponding to the four quantization units of unit [16] is 0.
Has been replaced by. Moreover, a part of the spectral coefficient information that is not referred to is replaced with the control information. The additional frame generation unit 65 receives supply of information indicating the original values of the changed normalization coefficient information and spectrum coefficient information (true normalization coefficient information and true spectrum coefficient information) from the band limitation processing unit 63. , The additional frame of FIG. 15 is generated.

In the additional frame, additional information corresponding to the tone component and additional information corresponding to the non-tone component are described. FIG. 15 shows a case where the quantization unit [1] to the quantization unit [12] are selected as the audition band. As the additional information corresponding to the tone component, the number of minimized tone components (here, two components are minimized), the position of the normalization coefficient information of each tone component on the listening frame, and the true normal The conversion factor information is described. As additional information corresponding to the non-tone component, the number of minimized non-tone component normalization coefficients (here, four components are minimized) and information indicating the position of the head of the normalization coefficient ( For example, the number 13 of the leading quantization unit in which the normalization coefficient is changed to 0 may be used), the rewritten true normalization coefficient, and the true spectral coefficient information of the rewritten portion in the control information. Has been done.

Here, the position information of the true spectrum coefficient information of the portion rewritten with the control information is not described in the additional frame to be generated, but the portion of the sample frame where the spectrum coefficient information is rewritten with the control information is not described. , If the beginning of the part that becomes the unreferenced spectral coefficient information, the position of the true spectral coefficient information of the part rewritten by the control information is based on the information of the region of the quantization unit in which the normalization coefficient is replaced by 0. It is possible to ask. If the position to be rewritten in the control information is different from the beginning of the part that becomes unreferenced spectral coefficient information, it is necessary to describe the position information of the true spectral coefficient information in the part rewritten in the control information in the additional frame. is there.

When the band limitation processing unit 63 changes the values such as the quantization accuracy information and the number of quantization units in addition to the normalization coefficient information and the spectrum coefficient information,
The additional frame generation unit 65 receives input of information indicating values such as the quantization accuracy information and the number of quantization units changed by the band limitation processing unit 63, and writes the information of the true values in the additional frame. .

Further, part or all of the normalization coefficient information described in the additional frame may be described in the control information. FIG. 16 shows an example of the format of control information in that case.

In the control information, the reproduction control information referred to when reproducing the trial listening data and the normalization coefficient information replaced in order to limit the band are described in whole or in part. In FIG. 16, all of the normalization coefficient information described in the additional frame is described regarding the non-tone component, but the information described here is, for example, part of the non-tone component. The normalization coefficient information may be all the replaced normalization coefficient information including the tone component, or when information other than the normalization coefficient information is replaced when the preview data is generated, Alternatively, those pieces of information may be described.

Further, the reproduction control information includes a reproduction enable flag in addition to the reproduction permission flag, the trial listening start flag, and the trial listening end flag described with reference to FIG.

The reproducible flag indicates whether or not reproducibility using the normalization coefficient information described in the control information is possible. Upon receiving the input of the trial listening data, the reproducing device refers to the reproducible flag of the control information in the trial listening frame, and when the normalization coefficient information is available, the normalization coefficient information in the control information is set to the original one in the trial listening frame. It is possible to restore the position and perform the reproduction process. In addition, when the reproducing apparatus that receives the input of the sample listening data indicates that the normalization coefficient information is not available in the reproducible flag, it reproduces without using the normalization coefficient information in the control information. Perform processing.

In the reproducible flag, it is possible to specify the version and type of the reproducing device. For example, in the reproducing device satisfying the specified version, the normalization coefficient information included in the control information is set. By using this, a part of the sample listening data can be restored and the reproduction process can be performed. On the other hand, in the reproduction device of the version other than the specified version, the normalization coefficient information included in the control information is included in the reproduction process. It cannot be used.

Also, by describing a part of the information to be added to the additional data in the control information, the data capacity of the additional data can be reduced, so that the user can record the additional data with, for example, MMK. The processing time can be shortened when recording on a medium, and the communication time can be shortened when additional data is obtained by downloading.

When the control information of FIG. 16 is inserted into the trial listening frame, the band limitation processing unit 63 does not use the additional frame generation unit 65 to replace all or part of the normalization coefficient information replaced to limit the band. , To the control information insertion unit 64. The control information insertion unit 64 includes a band limitation processing unit 63.
The control information of FIG. 16 is generated using the true normalization coefficient information input from, and is inserted into the sample frame.

Also, when a part of the information described in the additional frame, for example, the true normalization coefficient information of the non-tone part is described in the control information as described with reference to FIG. 16, The corresponding part is not described in the additional frame.

The trial-listening-data generating section 66 generates a header of the trial-listening data, adds the generated header to the encoded frame sequence of the input trial-listening data, and generates and outputs the trial-listening data. The header of the preview data includes, for example, a content ID for identifying the content, a reproduction time of the content, a title of the content, or information such as encoding method information.

The additional data generating section 67 generates a header of the additional data, adds the header of the generated additional data to the encoded frame sequence of the input additional data, and generates and outputs the additional data. In the header of the additional data, a content ID for identifying the content and associating it with the preview data, a reproduction time of the content, and information regarding an encoding method as necessary are described.

In this way, since the control information is described so that the trial listening area of the trial listening data is continuously reproduced, it is possible to prevent the protected area from being silently reproduced. It is possible to prevent the user who listens to the data from feeling uncomfortable.

Also, by describing various information relating to the reproduction of the sample listening data in the control information, it is possible to perform processing such as fade-in and fade-out at the beginning and end of the sample listening area, and Even when a plurality of trial listening areas that should be played in different portions are played back in succession, the user who auditioned the trial listening data can understand the continuous portion and the non-continuous portion of the original trial listening area. Alternatively, the reproduction quality of the preview data can be changed depending on the version of the reproduction apparatus.

Further, by including the true data replaced at the time of generating the trial listening frame in the control information, the data capacity of the additional data can be reduced, and the trial listening data can be changed depending on the type and version of the reproducing apparatus. It is possible to change the reproduction quality of.

The original data can be restored by the process described later by using the trial listening data generated by the trial listening data generating section 14 and the additional data.

Next, with reference to the flowcharts of FIGS. 17 and 18, the trial listening data generation process will be described.

In step S1, the trial-listening-data generation processing control section 61 acquires the set value of the trial listening band of the trial listening area of the trial listening data, which is input from an operation input section (not shown) or the like. Here, as the audition band, FIG. 11 and FIG.
The description will be made assuming that the quantization unit [1] to the quantization unit [12] are set as described above. The trial listening data generation processing control unit 61 supplies the set value of the trial listening band to the band limitation processing unit 63.

In step S2, the trial-listening-data generation processing control section 61 acquires information designating the trial-listening area of the trial-listening data, which is input from an operation input section (not shown) or the like. Here, as the audition area, the audition area 1 including the fourth and fifth frames described with reference to FIG.
The description will be made assuming that the audition area 2 including the tenth frame is designated. Trial data generation processing control unit 61
Supplies information specifying the trial listening area to the trial listening area determination unit 62.

In step S3, the audition area judging section 6
2 and the band limitation processing unit 63 receives an input of any frame included in the frame sequence corresponding to the original data, that is, the frame capable of high-quality sound reproduction described with reference to FIG.

In step S4, the audition area judging section 6
2 determines whether or not the input frame is a trial listening frame (frame included in the trial listening area) based on the information supplied from the trial listening data generation processing control unit 61.

If it is determined in step S4 that the input frame is a trial listening frame, step S4
In 5, the audition area determination unit 62 supplies the determination result to the band limitation processing unit 63 and the control information insertion unit 64, so that the band limitation processing unit 63 includes the normalization coefficient information of the tone component of the input frame. The portion other than the band designated by the set value of the trial listening band supplied from the trial listening data generation processing control unit 61 is changed to, for example, 0.

In step S6, the band limitation processing unit 6
3 shows, for example, the value of the non-tone component normalization coefficient information other than the band designated by the set value of the audition band supplied from the audition data generation processing control unit 61 is changed to 0. 11, the preview frame is generated and output to the control information insertion unit 64, and the true normalization coefficient information replaced in step S5 and step S6 and various information indicating its position,
The whole is output to the additional frame generation unit 65, or a part thereof is output to the control information insertion unit 64, and the other is output to the additional frame generation unit 65.

In step S7, the control information insertion unit 6
In No. 4, the control information indicating that the sample is available for listening is described in a part of the unreferenced spectral coefficient information corresponding to the normalized coefficient information of the non-tone component rewritten in the processing of step S6, and described with reference to FIG. Generate a preview frame. Here, even if the control information described is only the reproduction control information as described with reference to FIG. 14, a part of the information described in the additional data as described with reference to FIG. It doesn't matter whether it contains a. The control information insertion unit 64 outputs the generated audition frame to the audition data generation unit 66, and at the same time as step S
The true spectrum coefficient information replaced with the control information in 7 is output to the additional frame generation unit 65.

Here, when the spectrum coefficient information is variable-length coded, the control is such that the bit length when the control information is decoded is shorter than the bit length when the true spectrum coefficient information is decoded. By using the information,
In the decoding process described below, it is possible to prevent the frame length of the code string from being exceeded.

Further, the control information insertion unit 64 may replace dummy data in addition to the control information in a part of the spectral coefficient information that is not referred to. The dummy data to be replaced with the spectral coefficient information may have a value of 0, or may have a value of 1 and a value of 0 appropriately mixed.

[0187] In step S8, the additional frame generation section 65 has the band limitation processing section 63 and the control information insertion section 6
On the basis of the signal input from 4, the user, who has listened to the trial listening data, generates data for additional frames that constitute additional data to be purchased when listening to music with high sound quality.

If it is determined in step S4 that the input frame is not the trial listening frame, that is, it is a protection frame (frame included in the protection area), the trial listening area determination unit 62 determines in step S9 the determination result. The bandwidth limitation processing unit 63 and the control information insertion unit 64
Supply to. The band limitation processing unit 63 changes all of the tone component normalization coefficient information to the minimum value (value 0).

In step S10, the band limitation processing section 63 changes all the normalization coefficient information of the non-tone components to the minimum value (value 0) and outputs the normalization coefficient information to the control information inserting section 64. The true normalization coefficient information replaced in S10 and various information indicating the position thereof are all output to the additional frame generation unit 65, or a part of the information is output to the control information insertion unit 64,
Others are output to the additional frame generation unit 65.

In step S11, the control information insertion section 64 indicates, as a part of the unreferenced spectral coefficient information corresponding to the normalization coefficient information of the non-tone component rewritten in the processing of step S10, control information indicating that the preview is not possible. Enter. The control information insertion unit 64 outputs the generated audition frame to the audition data generation unit 66, and
The true spectrum coefficient information replaced with the control information in step S11 is output to the additional frame generation unit 65.

In the same manner, when the spectrum coefficient information is variable-length coded, the bit length when the control information is decoded is shorter than the bit length when the true spectrum coefficient information is decoded. The replacement is performed using such control information. Furthermore, in addition to the control information, the dummy data may be used for the replacement.

In step S12, the additional frame generation unit 65 determines whether the user who has auditioned the audition data listens to the music with high sound quality based on the signals input from the band limitation processing unit 63 and the control information insertion unit 64. Generate data for the additional frames that make up the additional data to purchase.

After the processing of step S8 or the processing of step S12 is completed, in step S13, the preview data generation unit 64 determines that the processed frame is
It is determined whether it is the last frame. Step S13
In, when it is determined that the processed frame is not the final frame, the process returns to step S3, and the subsequent processes are repeated.

If it is determined in step S13 that the processed frame is the final frame, in step S14, the preview data generation unit 66 generates a header of the preview data and adds it to the preview frame sequence. Generate audition data and output it.

In step S15, the additional data generation unit 67 uses the input information to generate a header of the additional data, adds the header to the additional frame sequence to generate and output the additional data, and the processing ends. It

By the processing described with reference to the flowcharts of FIGS. 17 and 18, the trial listening data in which only the trial listening area is reproduced with low quality and the additional data for restoring the original data from the trial listening data are generated.

Further, in order to motivate the user to purchase, the data in the trial listening area may have the same high sound quality as the original data without band limitation.
In that case, without band limiting the data in the audition area,
It suffices to copy the frame of the trial listening area of the original data as it is to the trial listening frame without generating an additional frame for that portion.

The signal component coding unit 1 of the coding apparatus 1
In the case of encoding the input signal, 2 has described that the tone component and the non-tone component are separated and separately encoded, but instead of the signal component encoding unit 12, the non-tone component of FIG. By using the tone component encoder 33, the input signal may be encoded without separating the tone component and the non-tone component.

FIG. 19 shows the format of a high-quality original data frame generated by the code string generation unit 13 when the input signal is not separated into the tone component and the non-tone component. As in the case described with reference to FIG. 8, a fixed-length header including a sync signal is arranged at the beginning of the original data frame. The header also records the number of band divisions of the band division filter 21 of the conversion unit 11 described with reference to FIG. Following the header, the number of quantization units (16 in this case), quantization accuracy information of the quantization performed by the non-tone component encoding unit 33, normalization coefficient information of each of the 16 quantization units, and spectrum coefficient information. Is recorded. The normalization coefficient information is recorded for each quantization unit from a value of 46 in the lowest quantization unit [1] to a value of 8 in the highest quantization unit [16]. Further, when the length of the content frame is a fixed length, an empty area may be provided after the spectrum coefficient information.

FIG. 20 shows the format of the audio data of the trial listening portion generated by the trial listening data generator 14 which receives the input of the original data frame described with reference to FIG. For example, the quantization unit [1] to the quantization unit [1
2] is designated, as in the case described with reference to FIG. 11, the quantization unit [13] on the higher side of the audition band.
To the value of the normalized coefficient information of the quantization unit [16] is 0
It is said that Therefore, a valid value is described in the spectral coefficient information of the portion corresponding to the quantization unit [13] to the quantization unit [16], but since the normalized coefficient information is 0 at the time of reproduction, The part of the spectrum is minimized. Then, the control information described with reference to FIG. 14 or 16 is described in a part of the spectrum coefficient that is not referred to.

Then, FIG. 21 shows an additional frame generated by the additional frame generation section 65 of the trial listening data generation section 14 which receives the input of the original data frame described with reference to FIG. Here, as the control information, FIG.
The additional frame in the case where only the reproduction control information described with reference to No. 4 is described will be described. The additional frame includes the number of normalized coefficients of the minimized quantized frame (here, the four components are minimized), the position of the beginning of the normalized coefficient, the rewritten true normalization coefficient, and the control. The true spectral coefficient information of the portion rewritten with information is described.

As described with reference to FIGS. 19 to 21, even in the case where the tone component is not separated, the same processing is performed, so that only the trial listening area has low quality and only the trial listening area is reproduced. Additional data is generated to restore the original data from the data.

The audition data thus generated is
Distributed to users via the Internet,
The MMK provided in a store or the like records and distributes on various recording media owned by the user. The user who likes the trial listening data and pays a predetermined fee to the content data distributor can obtain the additional data by reproducing the trial listening data. The user can restore the original data by using the preview data and the additional data, decode and reproduce the original data, or record it on the recording medium.

Next, the processing for decoding and outputting or reproducing the trial listening data, or decoding and outputting or reproducing the original data from the trial listening data and the additional frame will be described.

FIG. 22 is a block diagram showing the structure of the data reproducing device 81.

The code string disassembling unit 91 receives the input of the encoded audition data, decomposes the code string, extracts the code of each signal component, and outputs it to the code string restoring unit 93.

The control section 92 receives a user's operation from an operation input section (not shown), receives information indicating whether or not the input data is reproduced with high sound quality, receives additional data, and receives a code. The process of the column restoration unit 93 is controlled. Further, the control unit 92 supplies the true coding coefficient information, the true spectrum coefficient information, or the like to the code restoring unit 93 as necessary.

Under the control of the control unit 92, the code string restoring unit 93, when the input audition data is auditioned, that is, is reproduced as it is, the input coded frame is directly input to the signal component decoding unit 94. When the sample data that is output and input is reproduced by being restored to the original data, based on various information such as true coding coefficient information or true spectrum coefficient information supplied from the control unit 92, The process of restoring the coded frame of the trial listening data to the coded frame of the original data is executed, and the restored coded frame of the original data is output to the signal component decoding unit 94.

When the trial listening data is reproduced, the code string restoring unit 93 may restore some or all of the trial listening data by referring to the control information thereof. That is, the trial listening data includes true encoding coefficient information and the like, and the condition indicated by the reproducible flag that allows the trial listening data to be restored (for example, designation of the version of the data reproducing device 81) ) Is satisfied, the code string restoration unit 93 uses a part of the trial listening data, using the true coding coefficient information included in the trial listening data.
Alternatively, it is possible to restore the whole.

The signal component decoding unit 94 decodes the coded frame of the input audition data or original data. FIG. 23 shows that when an input encoded frame is divided into tone components and non-tone components and encoded,
It is a block diagram which shows the more detailed structure of the signal component decoding part 94 which decodes the coded frame.

The frame separating section 101 is, for example, as shown in FIG.
Receives an input of an encoded frame as described using
It is divided into tone component and non-tone component, and the tone component is
The tone component decoding unit 102 outputs the non-tone component to the non-tone component decoding unit 103.

FIG. 24 is a block diagram showing a more detailed structure of the tone component decoding unit 102. Inverse quantizer 111
Dequantizes the input coded data and outputs it to the denormalization unit 112. The denormalization unit 112 denormalizes the input data. That is, the inverse quantization unit 111 and the inverse normalization unit 112 perform decoding processing and output the spectrum signal of the tone portion.

FIG. 25 is a block diagram showing a more detailed structure of the non-tone component decoding unit 103. Inverse quantizer 12
1 dequantizes the input coded data and outputs it to the denormalization unit 122. The denormalization unit 122 denormalizes the input data. That is, the inverse quantization unit 121 and the inverse normalization unit 122 perform decoding processing and output the spectrum signal of the non-tone portion.

The spectrum signal synthesizing unit 104 receives the spectrum signals output from the tone component decoding unit 102 and the non-tone component decoding unit 103, synthesizes these signals, and if they are original data, FIG. If it is the trial listening data, the spectrum signal described with reference to FIG. 12 is generated and output to the inverse conversion unit 95.

If the encoded data is not encoded by being divided into tone components and non-tone components, the frame separation unit 101 is omitted and the tone component decoding unit 102,
Alternatively, the decoding process may be performed using only one of the non-tone component decoding units 103.

FIG. 26 is a block diagram showing a more detailed structure of the inverse conversion section 95.

The signal separation unit 131 separates the signal based on the number of band divisions described in the header of the input frame. Here, it is assumed that the number of band divisions is 2 and the signal separation unit 131 separates the input spectrum signal into the inverse spectrum conversion units 132-1 and 132-2.

Inverse spectrum converting sections 132-1 and 132-1
2-2 performs inverse spectrum conversion on the input spectrum signal, and outputs the obtained signal of each band to the band synthesis filter 133. The band synthesizing filter 133 synthesizes the input signals of the respective bands and outputs the synthesized signal.

The signal output from the band synthesizing filter 133 (eg, audio PCM signal) is converted into analog data by a D / A converter (not shown) and reproduced and output as voice from a speaker (not shown). Further, the signal output from the band synthesis filter 133 may be output to another device via a network or the like.

Next, the data reproducing process executed by the data reproducing device 81 shown in FIG. 22 will be described with reference to the flowchart shown in FIG.

The code string disassembling unit 91 receives the input of the encoded frame of the trial data in step S31, decomposes the input code string in step S32, and outputs it to the code string restoring unit 93.

In step S33, the code string restoration unit 9
3 determines, based on the signal input from the control unit 92, whether high-quality sound reproduction, that is, processing for restoring and reproducing original data is executed.

If it is determined in step S33 that high-quality sound reproduction is to be executed, in step S34
A code string restoration process described below is executed using the flowchart of FIG.

If it is determined in step S33 that the high-quality sound reproduction is not executed, the input frame is
Since it is reproduced as trial listening data, in step S35, the code string restoring unit 93 refers to the control information included in the input frame and determines whether or not this frame is a trial listening frame.

If it is determined in step S35 that this frame is not a trial-listenable frame, in step S36, the code string restoration unit 93 skips the processing for the input frame. That is, the code string restoration unit 93 discards the input frame without outputting it to the signal component decoding unit 94, and the process proceeds to step S39.

After the processing of step S34 is finished, or when it is determined in step S35 that this frame is a frame that can be auditioned, step S37.
In, the signal component decoding unit 94 divides the input code string into tone components and non-tone components, and
Decoding is performed by performing inverse quantization and inverse normalization, and the spectrum signals generated by the decoding are combined and output to the inverse transform unit 95.

In step S38, the inverse transformation unit 95
Performs band separation of the input spectrum signal as necessary, inverse spectrum transforms the respective spectrum signals, and then performs band synthesis to inversely convert the time-series signals.

Step S36 or step S3
After the processing of 8 is completed, the control unit 9
2 determines whether or not the inverse frame converted by the inverse converter 95 in step S38 is the final frame of the trial listening data.

If it is determined in step S39 that the frame is not the final frame, the process returns to step S31, and the subsequent processes are repeated. If it is determined in step S39 that the frame is the final frame, the process ends.

The time series signals inversely converted and generated by the inverse converter 95 may be converted into analog data by a D / A converter (not shown) and reproduced and output from a speaker (not shown). You may make it output to another device etc. via a network not shown.

Further, when the trial listening data is reproduced, the trial listening start flag and the trial listening end flag of the control information can be referred to as necessary to perform processing such as fade-in and fade-out.

[0232] Here, the description has been given of the case where the trial listening data in which the tone component and the non-tone component are divided and encoded, or the original data restored from the trial listening data is decoded. Even when the component and the non-tone component are not divided, the restoration process and the reproduction process can be similarly performed.

Next, the code string restoration process executed in step S34 of FIG. 27 will be described with reference to the flowchart of FIG.

In step S51, the code string restoration unit 9
The control unit 3 acquires additional data information such as trial listening area information, true coding coefficient information, and true spectrum coefficient information from the control unit 92 in order to restore the code string.

The code string restoring unit 93 receives an input of the frame decomposed by the code string decomposing unit 91 in step S52, and determines in step S53 whether the input frame is a trial listening frame.

If it is determined in step S53 that the input frame is a trial listening frame, in step S54 the code string restoring unit 93 determines whether the tone components included in the additional frame described with reference to FIG. The true value of the normalization coefficient information is used to restore the normalization coefficient information of the tone component of the portion replaced with 0 in the preview frame of the preview data.

In step S55, the code string restoration unit 9
3 uses the true value of the normalization coefficient information of the non-tone component included in the additional frame described with reference to FIG. 15 to normalize the non-tone component of the portion replaced with 0 in the audition frame of the audition data. Restore coefficient information.

In step S56, the code string restoration unit 9
3 uses the true value of the spectrum coefficient information of the non-tone component included in the additional frame described with reference to FIG.
The spectral coefficient information of the non-tone component of the portion replaced with the control information in the trial listening frame of the trial listening data is restored, and the process returns to step S37 in FIG.

When it is determined in step S53 that the input frame is not the trial listening frame, that is, the protection frame, the code string restoring unit 93 is included in the additional frame corresponding to the protection frame in step S57. Using the true value of the normalization coefficient information of the tone component, the normalization coefficient information of the entire tone component replaced with 0 in the trial listening frame of the trial listening data is restored.

In step S58, the code string restoration unit 9
3 uses the true value of the normalization coefficient information of the quantized frame of the non-tone component contained in the additional frame corresponding to the protection frame, and uses the true value of the normalization coefficient information of the non-tone component of the non-tone component of the trial listening frame of the trial listening data. Restore the normalization coefficient information.

In step S59, the code string restoration unit 9
3 uses the true value of the spectrum coefficient information of the non-tone component included in the additional frame corresponding to the protection frame,
The spectral coefficient information of the non-tone component of the portion replaced with the control information in the trial listening frame of the trial listening data is restored, and the process returns to step S37 in FIG.

By the processing described with reference to the flowchart of FIG. 28, the original data is restored using the trial listening data and the additional data.

Note that in FIG. 28, the original data is restored using the additional data described with reference to FIG. 15, that is, the true normalization coefficient information is all described in the additional data. However, if some or all of the true spectrum coefficient information is described in the control information, steps S54 and S55,
Alternatively, in step S57 and step S58, the code string restoring unit 93 restores the normalization coefficient information of the replaced portion using the true normalization coefficient information described in the control information in the preview frame. .

By the processing described with reference to FIG. 22 to FIG. 28, the decoded audition data or the original data restored and decoded can be reproduced, for example, over a network even if reproduced using a speaker (not shown). You may make it output to another apparatus via this.

Further, in FIG. 27, when the audition data in which the normalization coefficient of the quantization unit 13 to the quantization unit 16 is changed to 0 is reproduced, it corresponds to the quantization unit 1 to the quantization unit 12. It has been described that only band data is reproduced. On the other hand, the control information of the audition frame includes, for example, the true normalization coefficient of the quantization unit 13 and the quantization unit 14,
The reproducible flag permits the reproduction process using the true normalization coefficient information described in the control information, and the additional data includes the true normalization coefficient of the quantization unit 15 and the quantization unit 16. May be described. When the sample data is reproduced, the code string restoration unit 93
Is to restore the true normalization coefficient information of the quantization unit 13 and the quantization unit 14 based on the control information, and only the data in the band corresponding to the quantization units 1 to 12 is reproduced. Alternatively, it may be possible to perform a slightly better quality reproduction process.

When the trial listening data is normally reproduced, the code string restoring unit 93 does not refer to the normalization coefficient information included in the control data of the trial listening frame. Therefore, the quantization unit 1 to the quantization unit is reproduced. Only the data in the band corresponding to the unit 12 is available. For example, when the data reproducing device is a predetermined version, or when a predetermined password is input from an operation input unit (not shown) or the like, the control unit 92 controls the code string restoration unit 93, Quantization unit 13 included in control data of audition frame
Then, the true normalization coefficient of the quantization unit 14 is extracted, and the normalization coefficient of the corresponding portion is restored. As a result, it is possible to perform a reproduction process of slightly better quality than in the case where only the data in the band corresponding to the quantization units 1 to 12 is reproduced.

It should be noted that whether or not to refer to the true normalization coefficient of the quantizing unit 13 and the quantizing unit 14 included in the control data of the audition frame is determined by matching the version of the data reproducing device 81 or by checking the password. May be determined by a method other than the input of, for example, it may be determined in advance by the setting of the data reproducing device 81. In addition, when high-quality sound reproduction is performed, the code string restoration unit 93 can restore the normalization coefficients of all the quantization units based on the additional data supplied from the control unit 92. Needless to say that will be played.

Next, the trial listening data is recorded on the recording medium,
Alternatively, a process for restoring the original data from the trial listening data and the additional frame and recording the original data on the recording medium will be described.

FIG. 29 is a block diagram showing the structure of the data recording device 141.

The parts corresponding to those of the data reproducing device 81 of FIG. 22 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

That is, the code string disassembling unit 91 receives the input of the encoded audition data, decomposes the code string and extracts the code of each signal component, and the control unit 92 receives the operation input unit (not shown). In response to the user's operation, the input data is recorded with high sound quality, that is, the information indicating whether or not the process of restoring and recording the original data is executed, and the input of the additional data is received. , Control the processing of the code string restoration unit 93.

Under the control of the control unit 92, the code string restoration unit 93, when the input audition data is recorded,
When the input encoded frame is output to the recording unit 151 as it is, and the original data is restored and recorded, the input audition data is supplied from the control unit 92. A process of restoring the encoded frame of the original data is executed based on various information such as the encoded coefficient information and the true spectral coefficient information, and the restored encoded frame of the original data is output to the recording unit 151.

The recording section 151 is, for example, a magnetic disk,
Data is recorded on a recording medium such as an optical disc, a magneto-optical disc, a semiconductor memory, or a magnetic tape by a predetermined method. Further, the recording unit 151 may be one that records information therein, such as a memory provided in a substrate or a hard disk. For example, when the recording unit 151 can record data on the optical disc, the recording unit 151 converts the data into a format suitable for recording on the optical disc, a laser light source such as a laser diode, and various lenses. , And a deflection beam splitter, an optical unit, a spindle motor that drives the optical disc to rotate, a drive unit that drives the optical unit to a predetermined track position on the optical disc, and a control unit that controls them.

The recording medium mounted in the recording unit 151 is the same as the recording medium on which the sample listening data input to the code string decomposition unit 91 or the control unit 92 or the additional data was recorded. It may be.

Next, the data recording process executed by the data recording device 141 will be described with reference to the flowchart in FIG.

The code string disassembling unit 91 receives an input of the encoded frame of the trial data in step S81, decomposes the input code string in step S82, and outputs it to the code string restoring unit 93.

In step S83, the code string restoration unit 9
28, based on the signal input from the control unit 92, it is determined whether or not high-quality sound recording is to be executed.
The code string restoration process described with reference to the flowchart of FIG.

If it is not determined in step S83 that high sound quality recording is to be executed, or step S83
After the end of the processing of 84, in step S85, the recording unit 151 records the code string corresponding to the input original data or trial listening data on the mounted recording medium or the like.

At step S86, the control section 92
In step S85, it is determined whether or not what is recorded by the recording unit 151 is the last frame of the code string corresponding to the original data or the trial listening data.

If it is determined in step S86 that the frame is not the final frame, the process returns to step S81 and the subsequent processes are repeated. If it is determined in step S86 that the frame is the final frame, the process ends.

By applying the present invention, the value of the normalization coefficient information is changed, and further, the value of the normalization coefficient information is changed. ) Can be replaced with control information to generate preview data. It is extremely difficult to infer the original data from such audition data, and unauthorized modification of the audition data may cause deterioration of the sound quality. It is possible to protect the right of.

When the trial listening data is reproduced, even if a plurality of trial listening areas with low sound quality that can be listened to are set not only in one place but also in a plurality of trial listening frames constituting the trial listening data, it does not relate to the reproducing process. By inserting into a portion (for example, a region corresponding to unreferenced spectral coefficient information) and referring to control information indicating whether or not the corresponding audition frame can be auditioned, only the audition frame corresponding to the audition region is referenced. Is selectively played. Therefore, when the sample listening data is reproduced, the sample listening area is reproduced immediately after the reproduction is started, and unnatural silence is not reproduced.

Further, by describing information such as a trial listening start flag and a trial listening end flag in the control information, for example, when there are a plurality of trial listening areas, when the trial listening data is reproduced, fade-out is performed at each start position and end position. Since processing such as in and fade-out can be performed, the audition area, which should not originally be continuous, is not continuously reproduced at the same volume, and it is possible to provide the audition data that is easy for the user to hear.

Further, in the control information, a true value corresponding to the replaced data (for example, true normalization coefficient information, true spectrum coefficient information, true quantization accuracy information, or
Partial or total number of quantization units (such as the number of quantization units) and information such as a reproducible flag, for example, depending on the type and version of the reproducing apparatus, or whether a predetermined keyword is input. It is possible to control the quality of the trial listening data depending on whether or not it is.

Then, a true value (for example, true normalization coefficient information, true spectrum coefficient information, true quantization accuracy information, or true quantization coefficient information, or, corresponding to the data changed or replaced at the time of generating the trial listening data, or Since the additional data configured by the additional frame in which the number of quantization units and the like) is described, it is possible to restore the original data from the audition data using the additional data.

Furthermore, when a part or all of the information described in the additional frame is included in the control information, the data capacity of the additional data can be reduced. The communication time can be shortened, for example, when trying to obtain by downloading.

By applying the present invention, it is possible to reproduce and output the sample listening data and the restored original data, or output to another device via a network recorded on a recording medium or a network. is there.

In the above, the processing of generating the trial listening data of the content data by the audio signal and the corresponding additional data, and restoring the original data from the trial listening data and the additional data to reproduce or record the data has been described. The present invention can also be applied to content data composed of an image signal or an image signal and an audio signal.

For example, when the content data of the image signal is converted by using the two-dimensional DCT and quantized by using various quantization tables, a dummy quantization table in which high frequency components are omitted is used. Designation is performed, and if necessary, control information is recorded in the region of the spectrum coefficient information of the high frequency portion corresponding to the dummy to obtain trial listening data. In the additional data, the high frequency component of the missing quantization table and the replaced spectral coefficient information are described.

Then, when restoring the original data,
By using the additional data, the true quantization table in which the high frequency component is not lost is restored and the true spectrum coefficient information is restored, so that the original data can be restored and decoded.

The series of processes described above can be executed by hardware, but can also be executed by software. In this case, for example, the encoding device 1, the data reproducing device 81, or the data recording device 1
Reference numeral 41 is composed of a personal computer 161 as shown in FIG.

In FIG. 31, the CPU 171 has the ROM 172.
Stored in the program, or from the storage unit 178
Various processes are executed according to the program loaded in the RAM 173. The RAM 173 also appropriately stores data necessary for the CPU 171 to execute various processes.

CPU 171, ROM 172, and RAM 173
Are interconnected via a bus 174. An input / output interface 175 is also connected to the bus 174.

The input / output interface 175 includes an input unit 176 including a keyboard and a mouse, an output unit 177 including a display and a speaker, a storage unit 178 including a hard disk, a communication including a modem and a terminal adapter. The part 179 is connected. The communication unit 179 performs communication processing via a network including the Internet.

A drive 180 is also connected to the input / output interface 175 if necessary, and the magnetic disk 1
91, an optical disk 192, a magneto-optical disk 193, a semiconductor memory 194, or the like is appropriately mounted, and a computer program read from them is installed in the storage unit 178 as necessary.

When a series of processes are executed by software, a program that constitutes the software is installed in a computer in which dedicated hardware is installed, or various programs are installed to perform various functions. Is installed from a network or a recording medium into a general-purpose personal computer or the like capable of executing.

As shown in FIG. 31, this recording medium includes a magnetic disk 191 (including a floppy disk) in which a program is stored, which is distributed in order to supply the program to the user, separately from the apparatus main body, Optical disc 192 (CD-ROM (CompactDisk-Read Only Memor
y), DVD (including Digital Versatile Disk), magneto-optical disk 193 (including MD (Mini-Disk) (trademark)), semiconductor memory 194, etc. It is configured by a ROM 172 in which a program is stored, which is supplied to a user in a state of being pre-installed in the HDD, a hard disk included in the storage unit 178, and the like.

In the present specification, the steps for writing the program stored in the recording medium are not limited to the processing performed in time series in the order of inclusion, but are not necessarily performed in time series, but may be performed in parallel. Alternatively, it also includes processes that are individually executed.

Although the embodiments of the present invention have been described above, the present invention is not limited to such configurations. That is,
It is understood that the invention described in the claims and inventions equivalent thereto are included in the scope of the patent right to be granted to the present invention.

For example, in the above-mentioned embodiment, the first data string having the coding format shown in FIG. 8 has been exemplified, but the present invention is not limited to such a configuration. In the present invention, various other encoding formats can be applied to the first data string as long as the encoding format is capable of generating the second data string. Here, the second data string is data that is generated by replacing the first data of the first data string with the second data and that can be reproduced by substantially the same method as the first data string. It is a column. In the present invention, as the encoding format of the first data string,
For example, on a code string, at least a portion related to content data (for example, spectrum coefficient, pixel value, etc.) and coding parameters necessary for decoding the code (for example, quantization accuracy information, normalization coefficient information, etc.) It is preferable to apply a format in which is multiplexed. In this case,
For example, it is possible to multiplex the meta information describing the attribute of the content, the copyright management information, the encryption information, or the like on the code string.

[0281]

As described above, according to the first aspect of the present invention,
Data strings can be converted. Further, according to the first aspect of the present invention, for example, an original data string such as original data can be reproduced, for example, only a part of the original data string, and a part that cannot be reproduced is skipped without being processed during reproduction processing. It is possible to generate a data string such as additional data necessary for converting the data string to the trial listening data including the control information and restoring the original data string from the converted data string.

According to the second aspect of the present invention, it is possible to receive a data string and reproduce it. Further, according to the second aspect of the present invention, a reproducible portion and a non-reproducible portion are judged based on the control information, and only the reproducible portion is continuously reproduced. It is possible not to perform the reproduction of or the reproduction of only noise.

According to the third aspect of the present invention, the data string can be restored. Further, according to the third aspect of the present invention, a data string for restoring the data string, for example, additional data or the like, is separately acquired, so that the original data or the like becomes a base from the data string such as the trial listening data. Data strings can be restored.

According to the fourth aspect of the present invention, highly safe trial listening data can be distributed to users.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an encoding device to which the present invention has been applied.

FIG. 2 is a block diagram showing a configuration of a conversion unit in FIG.

FIG. 3 is a diagram illustrating a spectrum signal and a quantization unit.

FIG. 4 is a block diagram showing a configuration of a signal component encoding unit in FIG.

FIG. 5 is a diagram for explaining a tone component and a non-tone component.

FIG. 6 is a block diagram showing a configuration of a tone component encoding unit in FIG.

7 is a block diagram showing a configuration of a non-tone component encoding unit in FIG.

FIG. 8 is a diagram illustrating a format of a frame of original data.

9 is a block diagram showing a configuration of a trial listening data generation unit in FIG. 1. FIG.

FIG. 10 is a diagram illustrating a trial listening area and a protection area of an input frame sequence.

FIG. 11 is a diagram illustrating a format of a trial listening frame.

12 is a diagram illustrating a spectrum signal corresponding to the trial listening frame in FIG. 11. FIG.

FIG. 13 is a diagram illustrating a trial listening frame in which a part of the spectrum coefficient is rewritten using control information.

FIG. 14 is a diagram illustrating control information.

FIG. 15 is a diagram illustrating an additional frame.

FIG. 16 is a diagram illustrating control information.

FIG. 17 is a flowchart illustrating a trial listening data generation process.

FIG. 18 is a flowchart illustrating a trial listening data generation process.

FIG. 19 is a diagram illustrating a frame of original data when tone components are not separated.

FIG. 20 is a diagram illustrating a trial listening frame when tone components are not separated.

FIG. 21 is a diagram illustrating an additional frame when tone components are not separated.

FIG. 22 is a block diagram showing a configuration of a data reproducing device to which the present invention has been applied.

23 is a block diagram showing a configuration of a signal component decoding unit in FIG. 22.

FIG. 24 is a block diagram showing a configuration of a tone component decoding unit in FIG. 23.

FIG. 25 is a block diagram showing a configuration of a non-tone component decoding unit in FIG. 23.

FIG. 26 is a block diagram showing a configuration of an inverse conversion unit in FIG.

FIG. 27 is a flowchart illustrating a data reproduction process.

FIG. 28 is a flowchart illustrating a code string restoration process.

FIG. 29 is a block diagram showing a configuration of a data recording device to which the present invention has been applied.

FIG. 30 is a flowchart illustrating a data recording process.

FIG. 31 is a block diagram showing the configuration of a personal computer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 coding device, 11 conversion part, 12 signal component coding part, 13 code string generation part, 14 trial listening data generation part, 61 trial listening data generation processing control part, 62 trial listening area determination part, 63 band limitation processing part, 64 control Information insertion unit, 65 additional frame generation unit, 66 trial listening data generation unit, 67 additional data generation unit, 92 control unit, 93 code string restoration unit

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G10L 7/04 GF term (reference) 5D044 AB05 BC02 CC04 DE44 DE50 FG18 GK12 5D045 DA20

Claims (59)

[Claims] 1. A data conversion method of a data conversion device for converting a first data string into a second data string, wherein the first data included in the first data string is converted into a second data string.
Of the first replacement step, a second replacement step of replacing the third data included in the area different from the first data with the fourth data, and a first replacement step of Processing, and a first generation step of generating the second data string using the data generated by the processing of the second replacement step, and the fourth generation by the processing of the second replacement step. The third data to be replaced with the data of is the data recorded in the data recording area which is not used as the reproduction data when the second data string is reproduced, and the fourth data is the fourth data. 2. A data conversion method, characterized in that the control information is referred to when reproducing the second data string. 2. The data recording area in which the third data is recorded is reproduced when the second data string is reproduced by replacing the first data with the second data. The data conversion method according to claim 1, wherein the data recording area is not used as data. 3. The first data sequence and the second data sequence are each composed of a plurality of frames, the third data is recorded in each of the plurality of frames, and the second replacing step. The data conversion method according to claim 1, wherein the fourth data replaced with the third data by the process is control information indicating whether or not the corresponding frame can be reproduced. 4. A second data sequence for generating the third data sequence required to restore the second data sequence generated by the process of the first generation step into the first data sequence.
The third data string generated by the process of the second generating step, the first data replaced by the second data by the process of the first replacing step. The data conversion method according to claim 1, further comprising: and the third data replaced by the fourth data by the process of the second replacement step. 5. The position information indicating the position of the second data included in the second data string is further included in the third data string generated by the process of the second generating step. The data conversion method according to claim 4, wherein: 6. In the processing of the first replacing step, the reproduction quality is inferior when the second data string is reproduced than when the first data string is reproduced. The data conversion method according to claim 1, wherein the second data is replaced with the first data included in the first data string. 7. An encoding step of encoding input data is further included, wherein in the processing of the first replacing step, the encoded data encoded by the processing of the encoding step is converted into the first data. The data conversion method according to claim 1, wherein the first data is replaced with the second data as a column. 8. The data conversion method according to claim 7, wherein the first data includes a variable length code. 9. The data conversion method according to claim 7, wherein the first data includes normalization coefficient information of an encoding process by the process of the encoding step. 10. The data conversion method according to claim 7, wherein the first data includes quantization precision information of encoding processing by the processing of the encoding step. 11. The data conversion method according to claim 7, wherein the first data includes information indicating the number of quantization units of encoding processing by the processing of the encoding step. 12. A frequency component conversion step of converting input data into frequency components, the frequency component converted by the processing of the frequency component conversion step being a first signal composed of a tone component and a first signal
Further including a separation step of separating the signal into a second signal other than the above signal, and in the processing of the encoding step, different encoding processing is executed for the first signal and the second signal. The data conversion method according to claim 7. 13. The method further includes a frequency component conversion step of converting the input data into frequency components, and an encoding step of encoding the data converted into frequency components by the processing of the frequency component conversion step, In the process of the first replacing step, the first data is replaced with the second data by using the encoded data encoded in the process of the encoding step as the first data string, The said 3rd data replaced by the said 4th data by the process of a replacement step contain the spectral coefficient information of the frequency component converted by the process of the said frequency component conversion step, The claim 1 characterized by the above-mentioned. Data conversion method. 14. The first data is data indicating a predetermined numerical value, and the second data is a value obtained by minimizing the numerical value of the first data. Data conversion method described in. 15. The data conversion method according to claim 1, wherein the second data is obtained by replacing at least a part of the first data with random data. 16. The data according to claim 7, wherein the second data has a data length shorter than a data length when the first data is decoded when the second data is decoded. How to convert. 17. The fourth data includes at least a part of the first data replaced by the processing of the first replacement step, according to claim 1. Described data conversion method. 18. The fourth data, wherein at least a part of the first data included in the fourth data is used when the second data string is reproduced. The data conversion method according to claim 17, further comprising information indicating whether or not the second data can be restored. 19. A data conversion device for converting a first data string into a second data string, wherein the first data included in the first data string is converted into a second data string.
First replacing means for replacing the third data contained in an area different from the first data with fourth data, and the first replacing means, And a generation unit that generates the second data string using the data generated by the second replacement unit, and the third data replaced by the fourth data by the second replacement unit. The data is data recorded in a data recording area that is not used as reproduction data when the second data string is reproduced, and the fourth data is used when reproducing the second data string. A data conversion device characterized in that the control information is referred to. 20. A program for a data conversion device for converting a first data sequence into a second data sequence, wherein the first data contained in the first data sequence is converted into a second data sequence.
Of the first replacement step, a second replacement step of replacing the third data included in the area different from the first data with the fourth data, and a first replacement step of Processing and a generation step of generating the second data string using the data generated by the processing of the second replacement step, and the fourth data by the processing of the second replacement step. The replaced third data is data recorded in a data recording area that is not used as reproduction data when the second data string is reproduced, and the fourth data is the second data. A recording medium having a computer-readable program recorded thereon, which is control information that is referred to when a string is reproduced. 21. A computer-executable program for controlling a data conversion device for converting a first data sequence into a second data sequence, the first data being included in the first data sequence. The second
Of the first replacement step, a second replacement step of replacing the third data included in the area different from the first data with the fourth data, and a first replacement step of Processing and a generation step of generating the second data string using the data generated by the processing of the second replacement step, and the fourth data by the processing of the second replacement step. The replaced third data is data recorded in a data recording area that is not used as reproduction data when the second data string is reproduced, and the fourth data is the second data. A program characterized in that it is control information that is referred to when reproducing a sequence. 22. A second data string generated based on the first data string.
In the data reproducing method of the data reproducing apparatus for reproducing the second data string, a reproduction control step of controlling the reproduction of the second data string based on the control information included in the second data string, And the second data string are composed of a plurality of frames, and the plurality of frames of the second data string are controlled to be reproduced by the process of the reproduction control step. A data reproducing method, characterized in that the control information referred to in each case is included. 23. The control information is information designating whether or not a corresponding frame can be reproduced when the reproduction of the second data string is controlled by the processing of the reproduction control step. 23. The data reproducing method according to claim 22, wherein: 24. The second data string is generated by replacing the first data included in the first data string with second data, and the second data is processed by the process of the reproduction control step. 23. The data reproducing method according to claim 22, wherein the reproduction quality when reproduction of the string is controlled is inferior to that when the first data string is reproduced. 25. In the control information, the first data included in the first data string is replaced with the second data, so that the reproduction of the second data string is performed by the process of the reproduction control step. 25. The data reproducing method according to claim 24, wherein the data is recorded in a data area that is no longer used as reproduction data when is controlled. 26. The data reproducing method according to claim 24, wherein the control information includes at least a part of the first data replaced by the second data. . 27. At least a part of the first data included in the control information is included in the control information when the reproduction of the second data string is controlled by the process of the reproduction control step. 27. The data reproducing method according to claim 26, further comprising information indicating whether or not the second data can be restored by using. 28. A decoding step of decoding the second data string is further included, and in the process of the reproduction control step, reproduction of the second data string decoded by the process of the decoding step is controlled, 23. The data reproducing method according to claim 22, wherein the first data string is an encoded data string. 29. The data reproducing method according to claim 28, wherein the first data includes a variable length code. 30. The data reproducing method according to claim 28, wherein the first data includes normalization coefficient information. 31. The data reproducing method according to claim 28, wherein the first data includes quantization accuracy information. 32. The data reproducing method according to claim 28, wherein the first data includes the number of quantization units. 33. An inverse transform step for inverse transforming a frequency component, and the second transform step performed by the process of the inverse transform step.
Further comprising a decoding step of decoding the data string of, in the processing of the reproduction control step, the reproduction of the second data string decoded by the processing of the decoding step is controlled, and the first data string is 23. The data reproducing method according to claim 22, wherein the first data is a data string converted into a frequency component and encoded, and the first data includes spectral coefficient information. 34. The first data is data indicating a predetermined numerical value, and the second data is a value obtained by minimizing the numerical value of the first data. The data reproduction method described in. 35. The data reproducing method according to claim 22, wherein the second data is obtained by replacing at least a part of the first data with random data. 36. The second data, when decoded by the processing of the decoding step, has a shorter data length than the data length when the first data is decoded. Item 28. The data reproducing method according to Item 28. 37. A second generated based on the first data string
In the data reproducing apparatus for reproducing the second data string, there is provided reproduction means for reproducing the second data string based on the control information included in the second data string, the first data string and the second data string. Data sequence is composed of a plurality of frames, and each of the plurality of frames of the second data sequence includes the control information referred to when the second data sequence is reproduced by the reproducing device. A data reproducing device characterized by being included. 38. A second generated based on the first data string.
A program for a data reproducing device that reproduces the second data string, including a reproduction control step of controlling reproduction of the second data string based on control information included in the second data string, The first data string and the second data string are composed of a plurality of frames, and the plurality of frames of the second data string are reproduced by the process of the reproduction control step. A recording medium having a computer-readable program recorded thereon, the control information being referred to when controlled. 39. A second generated based on the first data string.
Is a program that can be executed by a computer that controls a data reproducing device that reproduces the second data string, and that controls reproduction of the second data string based on control information included in the second data string. The first data string and the second data string are composed of a plurality of frames, and the plurality of frames of the second data string include the second data by the process of the reproduction control step. The program is characterized in that the control information referred to when the reproduction of the data string is controlled. 40. A data restoration method of a data restoration device for restoring a first data string to a second data string, comprising the information necessary for restoring the first data string to the second data string. An acquisition control step of controlling acquisition of a third data string including the restoring step of restoring the second data string based on the third data string whose acquisition is controlled by the processing of the acquisition control step. The third data sequence includes first data for restoring the second data sequence, and in the process of the restoring step, the acquisition of which is controlled by the process of the acquisition control step is performed. The second data included in the first data string by replacing the first data included in the third data string with the second data included in the first data string.
The data restoration method, wherein a part of the second data is control information referred to when the first data row is reproduced. 41. The first data sequence is composed of a plurality of frames, the control information is included in each of the plurality of frames, and a corresponding frame is included when the first data sequence is reproduced. 41. The data restoration method according to claim 40, wherein the data is information designating whether or not is reproducible. 42. The control information includes at least a part of the first data for replacing the second data, and in the process of the restoring step, the control information includes the first data. The data restoration method according to claim 40, wherein the second data sequence is restored by further replacing the first data with the second data included in the first data sequence. 43. In the control information, when the second data string is restored by the process of the restoring step,
The information further including information indicating whether or not the second data can be restored using at least a part of the first data included in the control information. Item 42. The data restoration method according to Item 42. 44. The data restoration method according to claim 40, wherein the first data string is an encoded data string, and the first data includes a variable length code. 45. The third data string, the acquisition of which is controlled by the process of the acquisition control step, further includes position information indicating the position of the first data that replaces the second data. The data restoration method according to claim 40, wherein: 46. The data according to claim 40, further comprising a recording control step of controlling recording of the second data string restored by the processing of the restoring step on a predetermined recording medium. How to restore. 47. The data restoration method according to claim 40, further comprising a decoding step of decoding the second data string restored by the processing of the restoration step. 48. The data restoration method according to claim 47, further comprising a reproduction control step of controlling reproduction of the second data string decoded by the processing of the decoding step. 49. The data restoration method according to claim 47, wherein the first data sequence is an encoded data sequence, and the first data includes normalization coefficient information. 50. The data restoration method according to claim 47, wherein the first data string is an encoded data string, and the first data includes quantization accuracy information. 51. The data restoration method according to claim 47, wherein the first data sequence is an encoded data sequence, and the first data includes a number of quantization units. 52. The first data string is a data string converted into a frequency component and coded, and the first data contains spectral coefficient information. Data recovery method. 53. The first data is data indicating a predetermined numerical value, and the second data is a value obtained by minimizing the numerical value of the first data. Data recovery method described in. 54. The data restoration method according to claim 40, wherein the second data is obtained by replacing at least a part of the first data with random data. 55. The second data, when decoded by the processing of the decoding step, has a shorter data length than a data length when the first data is decoded. Item 47. The data restoration method according to Item 47. 56. A data decompression device for decompressing a first data sequence into a second data sequence, the third decompression device including information necessary for decompressing the first data sequence into the second data sequence. An acquisition unit that acquires a data string; and a restoration unit that restores the second data string based on the third data string acquired by the acquisition unit. A first data for restoring the second data string, wherein the restoring unit replaces the first data included in the third data string acquired by the acquiring unit with the first data. Restoring the second data string by replacing it with the second data contained in the data string,
The data restoration device, wherein a part of the second data is control information referred to when the first data string is reproduced. 57. A program for a data restoring device for restoring a first data string to a second data string, the information necessary for restoring the first data string to the second data string. An acquisition control step for controlling the acquisition of a third data string including the: and a restoration step for restoring the second data string based on the third data string whose acquisition is controlled by the processing of the acquisition control step. And the third data sequence includes first data for restoring the second data sequence, and in the process of the restoration step, the acquisition is controlled by the process of the acquisition control step. The second data string is restored by replacing the first data included in the third data string with the second data included in the first data string, and the second data string is restored. Part of the data is the first A recording medium on which a computer-readable program is recorded, which is control information to be referred to when reproducing the data string. 58. A computer-executable program for controlling a data restoration device for restoring a first data string to a second data string, wherein the first data string is restored to the second data string. An acquisition control step of controlling acquisition of a third data string including information necessary for performing the second data, based on the third data string whose acquisition is controlled by the process of the acquisition control step. A restoring step of restoring a row, the third data row includes first data for restoring the second data row, and in the processing of the restoring step, by the processing of the acquisition control step. By replacing the first data included in the third data string whose acquisition is controlled with the second data included in the first data string, the second data
And a part of the second data is control information that is referred to when reproducing the first data string. 59. A data format of trial listening data distributed for trial listening with respect to original content data, wherein a plurality of data formats are set so that reproduction quality is deteriorated as compared with a corresponding portion of the content data. A frame, the frame includes an area that is not used as reproduction data at the time of reproduction because the reproduction quality is set to be lower than that of the content data, and an area that is not used as reproduction data at the time of reproduction is
A data format in which control information used during reproduction is recorded.