JP3843619B2 - Digital information transmission method, encoding device, recording medium, and decoding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital information transmission method, an encoding device, a recording medium, and a decoding device in which analog information such as music information and video information is A / D converted by PCM, and particularly to digital information such as music information and video information. The present invention relates to a method of adding various information related to the information.
[0002]
[Prior art]
As media for transmitting PCM digital information (user data) such as music information and video information, recording media such as DVD, CD, MD, satellite broadcasting and terrestrial broadcasting, and communication media such as telephone lines and the Internet are known. ing.
[0003]
[Problems to be solved by the invention]
By the way, when transmitting user data (actual data) such as music information and video information, there is a need to add and transmit various information related to the user data information. Examples of the various additional information include (1) copyright information related to user data, (2) enhanced processing information related to music information, reverberation additional information, high frequency component additional information, and consonant cut information for improving clarity. And (3) embedded information such as a watermark for a recording medium and a transmission path, and an encryption key.
[0004]
As a method of transmitting such additional information together with user data, a method of dividing the transmission format into a user data field and a control field and setting it in individual fields, and a method of adding it to user data as they are are considered. However, in the former method, the format of a recording medium such as a DVD, CD, MD, etc. is standardized, so that the versatility is lost when a special format is used. Further, in the latter method, the user data itself changes and the restoration value (D / A conversion value) deteriorates differently from the original value, and the audibility of music information and the visual information of video information differ. There is.
[0005]
In view of the above problems, the present invention can ensure compatibility with the format of a transmission medium when adding various information related to the information to digital information such as music information and video information. It is an object of the present invention to provide a digital information transmission method, an encoding device, a recording medium, and a decoding device capable of preventing data from deteriorating and different from human hearing and vision.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention detects whether or not a silent section of PCM digital information continues for a predetermined number of samples, and follows the silent section when the silent section continues for a predetermined number of samples. When PCM digital information is delayed by a predetermined number of samples and converted into an analog signal at the time of decoding between a point in time when the silent period continues by a predetermined number of samples and the start point of the PCM digital information following the silent period PCM additional information that is a detection limit for the viewer is inserted.
That is, according to the present invention, detecting whether or not the silent section of the PCM digital information continues for a predetermined number of samples ;
When the silent period continues for the predetermined number of samples, the PCM digital information following the silent period is delayed by the predetermined number of samples, and the silent period continues for the predetermined number of samples; Inserting PCM additional information that becomes a detection limit for a viewer when converted into an analog signal at the time of decoding between the start point of the PCM digital information following the silent period ;
And transmitting over the medium the PC M digital information and the PCM additional information,
A digital information transmission method is provided.
[0007]
According to the present invention, means for detecting whether or not a silent section of PCM digital information continues for a predetermined number of samples ;
When the silent period continues for the predetermined number of samples, the PCM digital information following the silent period is delayed by the predetermined number of samples, and the silent period continues for the predetermined number of samples; Means for inserting PCM additional information that becomes a detection limit for a viewer when converted into an analog signal at the time of decoding between the start point of the PCM digital information following the silent section ,
An apparatus for encoding digital information is provided.
[0008]
According to the present invention, a recording medium of digital information the PC M digital information and the PCM additional information encoded by the encoding apparatus according to claim 2, wherein is recorded is provided.
[0009]
According to the present invention, the decoding device of a digital information decoding the PC M digital information and the PCM additional information according to any one of claims 1 to 7 is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 is an explanatory diagram showing an embodiment of a digital information transmission method according to the present invention, FIG. 2 is an explanatory diagram showing additional information of FIG. 1, FIG. 3 is a block diagram showing an encoding device, and FIG. 4 is a decoding device. FIG.
[0011]
The vertical axis in FIG. 1 indicates PCM digital values such as music information and video information in analog quantities, and the horizontal axis indicates time. For example, in the case of a CD, the digital value of the PCM is a sampling frequency fs = 44.1 kHz and the number of quantization bits of one sample = 16 bits. In the present invention, based on this digital value, it is detected whether or not the silent section continues for a predetermined number of samples from the end of the section (1) that is not the silent section. A total of 52 samples of additional information (3) consisting of 10 actual information is inserted. Therefore, the actual data {circle around (2)} not behind the silent section is delayed by 52 samples.
[0012]
In the example illustrated in FIG. 2, one piece of numeric information “0” to “9” in decimal is represented by four samples. Therefore, when the number of quantization bits of one sample is 16 bits as in a CD, one piece of numerical information can be represented by 4 × 16 bits. For one sample, only decimal “0” or “1” is used. That is, “0” indicates that 16 bits are all zeros, “1” indicates that LSB is “ 1 ”, and upper 15 bits indicate all zeros. Therefore, even when such additional information “circled number 3” is added and converted to an analog value on the decoder side, the sense of incongruity of the level difference is not perceived. That is, such additional information is information that becomes a detection limit well known in the world of sound. The delay of the subsequent actual data “circled number 2” when the additional information “circled number 3” for 52 samples is added is 52 / 44100≈1.2 msec in the case of CD (fs = 44.1 kHz).
Therefore, this delay does not cause a sense of incongruity on hearing.
[0013]
The additional information {circle over (3)} may be represented not by numbers but by English letters such as A to Z. In this case, it can be represented by five samples. Also, both numbers and English letters may be used. Further, the present invention is not limited to the 2's complement code, and when compression is performed, additional information such that the D / A conversion value is 0, 0-1 LSB, 0 + LSB may be used. Further, if the additional information (3) is inserted under the condition that the stereo two-channel signals L and R change in the same way, it is possible to further prevent a sense of incongruity on hearing. For the 12-sample preamble code, the LSB of the sum of 4 samples × 10 real information may be used as a parity code in order to prevent erroneous recognition of the real data (1) and (2).
[0014]
Next, the encoding apparatus will be described with reference to FIG. The analog audio signal is sampled by the A / D converter 101 at a certain sampling frequency fs, and then converted into PCM data by 1 sample = a certain number of quantization bits. The silence detection unit 102 detects whether or not the silence interval continues for a predetermined number of samples based on the PCM data. If the silence period continues, the delay unit 103 converts the PCM data into the predetermined number of inserted samples of the additional information (3). And the additional information generating unit 104 controls to generate the additional information (3) having a predetermined number of samples, and further, the switch SW is set to a predetermined number of inserted samples from the delay unit 103 side. Switch to the additional information generation unit 104.
[0015]
By this processing, when the silent section does not continue for a predetermined number of samples, the PCM data is output as it is through the switch SW without being delayed by the delay unit 103, while the silent section continues for the predetermined number of samples. The PCM data is delayed by a predetermined number of inserted samples by the delay unit 103, and the additional information (3) is output through the switch SW and inserted into the PCM data during the delay period. Data output via the switch SW is transmitted via a recording medium 105 such as a DVD, CD, or MD, or a communication medium such as a telephone line or the Internet. Note that the silent section may be determined as a silent section not only when each bit of the PCM data is all zero but also when only the LSB is “1”.
[0016]
Next, the decoding apparatus will be described with reference to FIG. First, the PCM data transmitted via the recording medium 105 or the communication medium is applied to the digital signal processing unit 106 and the additional information detection unit 107, and the additional information detection unit 107 includes additional information (3) in the PCM data. For example, based on the pre-ampule in the additional information (3) shown in FIG. If the additional information {circle over (3)} is included, the digital signal processing unit 106 processes the PCM data based on the additional information {circle around (3)} and outputs it via the D / A converter 108.
[0017]
Next, FIGS. 5 to 9 show a second embodiment in which copyright identification information is inserted as additional information (3) into a music source and transmitted via a DVD. Note that this copyright identification information is, for example, a signal that prohibits or permits a user to copy a music source transmitted via a DVD as a digital stream.
[0018]
First, in the encoding apparatus shown in FIG. 5, the analog audio signal input via the input terminal IN is high-sampled by the A / D converter 1 at a sufficiently high sampling frequency, for example, 192 kHz, and is, for example, a 24-bit high-resolution PCM signal. Is converted to This digital signal is applied to the signal processing circuit 2 and the memory 3, and the copyright identification signal from the copyright identification signal generation circuit 40 is inserted, and then packed into user data (packets) every 2034 bytes.
[0019]
As shown in FIG. 6, the DVD encoding circuit 4 adds a 14-byte pack header to the 2034-byte packet. The pack header includes a 4-byte pack start field, a 6-byte SCR field, a 3-byte Mux rate field, and a 1-byte stuffing field. This packing data is output to the output terminal OUT1, or is modulated by the modulation circuit 5 by a modulation method corresponding to the medium and output to the output terminal OUT2. A master recording medium can be created based on the output signal of the output terminal OUT2, and the master recording medium can be copied to a commercially available recording medium (for example, a DVD-ROM).
[0020]
Next, the decoder of the second embodiment will be described with reference to FIG. The input signal is first demodulated by the demodulation circuit 11 in accordance with the modulation method of the modulation circuit 5 on the encoder side, and then unpacked by the DVD decoding circuit 12 to restore user data (packets). This user data is output in the form of a bit stream to the digital output terminal 22 via the switch 21 and applied to the signal processing circuit 13 (and the memory 14).
[0021]
In the signal processing circuit 13, the bit stream of user data is separated into the original PCM data sampled at 192 kHz and the copyright identification signal. The PCM data is converted into an analog signal by the D / A converter 15b and output. Further, based on the copyright identification signal, it is determined whether or not the user is allowed to copy the digital stream as it is, and if so, the switch 21 is controlled to be turned off. Therefore, according to the second embodiment, copying of the audio stream that is high-sampled at 192 kHz, A / D converted and recorded on the recording medium is permitted based on the identification signal inserted in the audio stream. Or prohibited.
[0022]
Next, a third embodiment will be described with reference to FIG. The decoder side shown in FIG. 8 is configured such that the enhancement circuit 100 performs processing by the control signal 400 when the enhancement processing is instructed by the operation input unit 300, and whether or not the audio signal has been enhanced by the encoder side. Is inserted as additional information (3). On the decoder side shown in FIG. 8, the audio stream separated by the signal processing circuit 13 and this identifier are applied to the enhancement circuit 100 and the latch 200, respectively, and the identifier is prioritized over the operation input unit 300 and the identifier has enhanced processing. In this case, the processing of the enhanced circuit 100 is turned on, and when the identifier is not enhanced processing, the processing of the enhanced circuit 100 is turned off.
[0023]
Note that the additional information (3) can be applied to identification information such as reverberation additional information related to music information, high-frequency component additional information, consonant cut information for improving intelligibility, etc. in addition to the above embodiment. it can. Furthermore, the present invention can also be applied to embedded information such as watermarks and encryption keys related to recording media and transmission paths. PCM data can be applied to video signals in addition to audio signals. In this case, additional information (3) is a visually unrecognizable color area (for example, black) on the display screen on the decoder side. Area) and lines are inserted on the encoder side.
[0024]
【The invention's effect】
As described above, according to the present invention, when various information related to information is added to digital information such as music information and video information, whether or not the silent section of PCM digital information continues for a predetermined number of samples. When the silence interval continues for a predetermined number of samples, the PCM digital information that follows the silence interval is delayed by a predetermined number of samples, and the silent interval continues for a predetermined number of samples and the silence interval Since the PCM additional information that becomes a detection limit for the viewer when converted into an analog signal at the time of decoding is inserted between the start point of the PCM digital information that follows and the compatibility with the format of the transmission medium In addition, it is possible to prevent the human hearing and vision from being different due to deterioration of actual data.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a first embodiment of a digital information transmission method according to the present invention.
FIG. 2 is an explanatory diagram showing additional information in FIG. 1;
FIG. 3 is a block diagram showing an encoding apparatus.
FIG. 4 is a block diagram illustrating a decoding device.
FIG. 5 is a block diagram illustrating an encoding apparatus according to a second embodiment.
FIG. 6 is an explanatory diagram showing a DVD audio pack as a recording medium according to the second embodiment;
FIG. 7 is a block diagram illustrating a decoding device according to a second embodiment.
FIG. 8 is a block diagram illustrating a decoding device according to a third embodiment.
[Explanation of symbols]
102 Silence detection unit (detection means)
103 delay unit (combining insertion means together with additional information generating unit 104)
104 Additional information generator

Claims (8)

Detecting whether or not the silent section of the PCM digital information continues for a predetermined number of samples ;
When the silent period continues for the predetermined number of samples, the PCM digital information following the silent period is delayed by the predetermined number of samples, and the silent period continues for the predetermined number of samples; Inserting PCM additional information that becomes a detection limit for a viewer when converted into an analog signal at the time of decoding between the start point of the PCM digital information following the silent period ;
And transmitting over the medium the PC M digital information and the PCM additional information,
A method for transmitting digital information. Means for detecting whether a silent section of the PCM digital information continues for a predetermined number of samples ;
When the silent period continues for the predetermined number of samples, the PCM digital information following the silent period is delayed by the predetermined number of samples, and the silent period continues for the predetermined number of samples; Means for inserting PCM additional information that becomes a detection limit for a viewer when converted into an analog signal at the time of decoding between the start point of the PCM digital information following the silent section ,
An apparatus for encoding digital information. Recording medium of digital information the PC M digital information and the PCM additional information encoded by the encoding apparatus according to claim 2, wherein is recorded. Method of transmitting digital information as claimed in claim 1, wherein the original signal is an audio signal of the PCM digital information. Encoding apparatus of digital information according to claim 2, wherein the original signal is an audio signal of the PCM digital information. 2. The digital information transmission method according to claim 1, wherein the PCM additional information is a combination of a D / A conversion value of 0, 0-1 LSB, and 0 + 1 LSB. 3. The digital information encoding apparatus according to claim 2, wherein the PCM additional information is a combination of D / A conversion values of 0, 0-1 LSB, and 0 + 1 LSB. The PC M digital information and decoding apparatus for digital information for decoding the PCM additional information according to any one of claims 1 7.

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