JPS6230435A - Multiplexing method - Google Patents

Abstract

PURPOSE:To reproduce non-acoustic information as a sound excluding a peak sound with a reproducing device by scrambling the non-acoustic information divided into M bits and then replacing the lower order M bit by the non-acoustic sound to transmit or record the replaced information. CONSTITUTION:Exclusive OR between a data string Ai=[a(i,o)] and outputs Pi=[P(i,o)] of an M-sequence generator 2 is found out to obtain Bi=[a(i,o)(+)(i, o)]. Acoustic information is converted into digital data consisting of 4 bits and the lowest order bit is replaced by the output of an exclusive OR arithmetic unit 3 and these data including the output of the element 3 are transmitted to a transmission system. In a decoding method, the output of an exclusive OR arithmetic unit 14 for finding out exclusive OR between the transmitted data and the output P(i,o) of an M-sequence generator 13 is decoded to a(i,o). Even if all bit information from the transmission system is applied to a D/A converter 11, the acoustic information outputted through a low pass filter 12 is reproduced as a sound having no peak because the frequency spectrum of the lowest order bit is flat.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a multiplexing method for simultaneously transmitting or recording acoustic information and non-harmonic information on a transmission system or recording medium for the purpose of transmitting or recording high quality acoustic information. It is related to.

2. Description of the Related Art In recent years, with the development of digital technology, recording media, etc., it has become possible to digitally record and reproduce high quality acoustic information. Specific examples of such media include compact discs (hereinafter referred to as CDs) and digital audio tapes, but in these media, it is possible to reproduce large amounts of still images, which conventionally require a large amount of information, at the same time as audio information. was difficult.

Therefore, as a method for simultaneously reproducing a large amount of non-acoustic information such as a still image with acoustic information, a method was devised in which the lower M bits (M≦N) of the acoustic information with the number of quantized bits N are treated as the non-acoustic information recording area. has been done.

(Japanese Patent Application No. 59-203426 "Data Recording Method") The above-mentioned conventional array will be briefly explained below using a CD.

FIG. 4 shows the data structure when l=16 and M=3, and FIG. 6 shows the reproduction system.

Data on a CD recorded in the structure shown in Figure 4 is
The upper 13 bits are output by the player 1 via a digital-to-analog converter (hereinafter referred to as D/mu) and reproduced as audio information, and the lower 3 bits are stored in the frame memory 2.
is output and played back as a still image. The current specifications for still images are screen size 612 dots x 480 lines R, G.
, B are converted into a luminance signal (hereinafter referred to as Y) and two types of color difference signals (hereinafter referred to as R-Y and B-Y, respectively), and then the sub-Nyquist sampling method is used to convert Y for each line. Let us consider data in which R-Y and B-Y are compressed to 266 dots and 64 dots each. (Reference material patent patent application 1986-5
No. 1625 "Image Memory Device") If the data amount of 384 bytes per line is recorded in the lower 3 bits shown in FIG. 4, it becomes 1024 samples. This 1 line data is 1/
If recorded at 76 seconds, one screen will be played back in 6.4 seconds. That is, it is possible to simultaneously reproduce continuous audio information and image information on more than 500 images on one CD.

Now, the sixth data format for the above method is
As shown in the figure (IL), Y, Y, Y, Y, R-Y,
When 64 sets of 48-bit data each consisting of one set of B-Y are consecutively arranged for one line, when viewed in units of 3 bits (1 sample), there are 16 samples as shown in FIG. 6(b).

CD data has a data structure in which the R2 channel is repeated alternately, so if you look at each channel, 1
There are 8 samples in each group.

Problems to be Solved by the Invention CDs recorded using the above method can be used as audio-only CDs.
We will discuss what kind of influence the lower three bits of image information have when played back on a player.

It is known that images generally have a high correlation in the vicinity, and for this reason, the reproduced signal has approximately 6.5 degrees (=44
．． 1 KHVa sample) and its harmonics contain peak spectra, which can produce unfavorable results in terms of audibility. Furthermore, since the correlation between images is high between lines, this conventional array also included peak spectra in 75H2 and its harmonics. As a result, when the lower three bits are reproduced as acoustic information, there is a problem in that noise having a peak spectrum causes an undesirable audible phenomenon.

Means for Solving the Problems In order to solve the above problems, the multiplexing method of the present invention uses M
(M is a positive integer) First data string Ai consisting of non-acoustic information divided into bits == (z(i, M-1), a(i, M-2),
・=-, a(i, 1)+a(i, O)) However, a(i, j) is 0 or 1, i is the data sequence number,
j performs scrambling processing on the bit position to generate the second data string Bi=(+)(i, M-1), b(i, M-2),...
..., b(i, 1).

b(i, 0)) However, b(i, j) is 0 or 1, i is the data sequence number, ko is the bit position, and quantization is performed using the number of quantization bits N (N is an integer of N and M). The third data string C1 is composed of acoustic information of L (L is a positive integer) channels, which are obtained by
----, c(i.

1), c(i, 0)) However, O(i, j) is 0 or 1, i is the data string number, and j is obtained by replacing the lower M bits of the bit position with the above second data string. Fourth data string Di(1(i, N-1), d(i, N-2),...
..., d(i.

1) , d(i, O) ) However, d(i, j) is 0 or 1. i is a data sequence number, and j is a bit position to be transmitted or recorded.

Effect of the Invention With the above configuration, the present invention uses the scrambling process applied to the first data string to disperse peak spectra within the acoustic information band that occur during formatting due to the correlation of non-acoustic information. Even if the non-acoustic information multiplexed into the audio information is reproduced as acoustic information, the spectrum of the non-acoustic information is flat within the band of the acoustic information and becomes mere white noise, so that no auditory problems are caused.

EXAMPLE Hereinafter, a multiplexing method of one embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 shows one implementation of the present invention, in which the number of bits for converting audio information N=4. Number of channels L=1. Number of bits of non-acoustic information M
FIG. 2 is a block diagram of a circuit that implements a multiplexing method when =1. Reference numeral 1 designates an M-D converter that converts analog acoustic information into digital data, 2 an M-sequence generator that generates data in the analog sequence according to a sampling clock, and 3 an exclusive OR operator.

The operation of the multiplexing method of this embodiment constructed as described above will be explained below with reference to FIGS. 1 and 3.

If non-acoustic information has a correlation with the original signal like image information, the data string after formatting as described in the conventional column will have a frequency spectrum as shown in Figure 3 (IL). It has a peak. This data string person 1 = (
a(i,0)) is the output Pi=(P(
i, 0)) is taken, and Bi=(a(i, o
)(j)P(i,0)) is obtained. As a result, the frequency spectrum of the data string Bi has a characteristic without a peak, as shown in FIG. 3(b). For the M sequence used here, a characteristic polynomial having a period sufficiently longer than the correlation period after formatting may be selected.

For example, G(3C) = x ”-+x 12+x”+x'
+1 available.

The acoustic information is converted into 4-bit digital data by the AD converter 1, and the least significant bit is converted to 4-bit digital data by the exclusive OR operator 3.
is replaced with the output of , and sent to the transmission system.

A method for decoding data multiplexed as described above will be described next.

FIG. 2 is a block diagram of a circuit that realizes decoding of the encoded data obtained by processing in FIG. 1.

11 is D for converting digital information into analog audio information
A converter, 12 is a low-pass filter that removes folded components of DA-converted data, 13 is an M-sequence generator that generates M-series data according to the sampling clock, and 14 is an exclusive OR operator. . The operation of the decoding method configured as above will be explained. The least significant bit of the 4-bit data obtained from the transmission system is Bi = (b(i, 0
)), as described in the explanation of the encoding method in Figure 1, b(i, o) = a(1, 0) ■ P(i, O), and M
When the exclusive OR is performed with the output P(i, o) of the sequence generator 13, the output of the exclusive OR operator 14 is decoded as a(i, O). On the other hand, even if all bit information from the transmission system is added to the zero-person converter 11, the frequency spectrum of the least significant bit is flat, so the acoustic information output through the low-pass filter 12 is reproduced as sound without peak sound. be done.

In this embodiment, the number of bits of information to be transmitted is 4 bits and the number of bits of non-acoustic information is 1 bit, but it is generally possible to set the total number of bits to N bits and the number of bits of non-acoustic information to be V bits. it is obvious.

Furthermore, in this embodiment, the number of transmission channels is one, but it is clear that the same implementation can generally be achieved even if the acoustic information is L channels.

Effects of the Invention As described above, the present invention scrambles non-acoustic information divided into V-bit units, and then replaces the lower V bits of the N-bit quantized acoustic information with the non-acoustic information. Since the information is transmitted or recorded as N-bit acoustic information, an excellent effect with high compatibility can be obtained in that it can be reproduced by a normal reproduction device as a sound that does not include peak sounds.

Furthermore, since the multiplexed non-acoustic information is assigned to different bits from the audio information, it is possible to obtain the effect that separation is extremely easy.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a circuit that realizes the encoding of the multiplexing method in the embodiment of the present invention, FIG. 2 is a block diagram of a circuit that realizes the decoding of the multiplexing method performed in FIG. 1, and FIG.
1 is a frequency spectrum diagram for explaining the operation of FIG. 1, FIG. 4 is a data structure diagram, FIG. 6 is a block diagram of a conventional reproduction system, and FIG. 6 is a data format. 1... Mu D converter, 2, 13... V sequence generator, 3.14... Exclusive OR operator,
11...DM converter, 12...°゛・Low pass filter. Name of agent: Patent attorney Toshio Nakao and 1 other person
lrl! i 21st! A

Claims (5)

[Claims] (1) First data string Ai consisting of non-acoustic information divided into M (M is a positive integer) bits = (a(i, M-1), a(i, M-2),...・
..., a(i, 1), a(i, 0)) where a(i, j) is 0 or 1, i is the data sequence number, and j is the bit position that is scrambled and 2 data string Bi=(b(i, M-1), b(i, M-2),...
..., b(i, 1), b(i, 0)) However, b(i, j) is 0 or 1, i is the data sequence number, j is the bit position, and the number of quantization bits N( A third data string Ci=(C(i, N-1), C(i, N-2),...
... , C(i, 1), C(i, 0)) However, C(i, j) is 0 or 1, i is the data sequence number, and j is the lower M bits of the bit position in the above second Fourth data string Di=(d(i, N-1), d(i, N-2),...
..., d(i, 1), d(i, 0)) However, d(i, j) is 0 or 1, i is a data sequence number, and j is a bit position that is transmitted or recorded. multiplexing method. (2) The first data string Ai and the fifth data string Pi in which all bits of M-bit data are generated by M sequences = (P(i, M-1), P(i, M-2) ),...
..., P(i, 1), P(i, 0)), the second data string Bi is obtained from the relationship Bi=Ai■Pi. multiplexing method. (3) The M bits of the second data string Bi are replaced with the lower M bits of the third data string Ci, and the fourth data string Di=(c(i, N-1),...・,c(i,M
), b(i, M-1), ......, b(i, 1),
2. The multiplexing method according to claim 1, characterized in that the multiplexing method obtains b(i, 0)). (4) The first data string Ak (k=L×m-l, m is a positive integer, l is an integer satisfying 0≦l<L) and the fifth data string Pm
2. The multiplexing method according to claim 1, wherein the second data string Bk is obtained from the relationship Bk=Ak■Pm. (5) M bits of the second data string Bk are converted to data C of the l-th (l is an integer of 0≦1<L) channel of the third data string.
The lower M bits of m, l are replaced with the fourth data string Dm, l=(c(m, l, N-1), . . ., c
(m,l,M)b(k,M-1),...,b(
The multiplexing method according to claim 1, characterized in that the multiplexing method obtains k, 1), b(k, 0)).