JPS62119772A - Disk reproducing device - Google Patents

Abstract

PURPOSE:To reproduce the sound of a prescribed channel by selecting a channel setting counter only, by inserting synchronizing signals into the serial data of plural channels at prescribed periods. CONSTITUTION:By producing pulses only when a coincidence circuit 4 composed of an EX-OR circuit, etc., detects the coincidence between the values of a counter 3 and channel counter 2, data of a prescribed channel only in the data CD of plural channels are latched by a register 6, to which data 11 are added. At this time, floating point data are also given to a floating point data latching circuit 5 similarly. A shift pulse producing circuit 7 is equipped with a counter which increases its count value until the count value coincides with floating point data which determines a shift value and stops when the count value coincides with the data and, when the clocks until the coincidence is obtained are used as shift clocks, shift clocks can be obtained easily.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The invention is related to an original disk playback device such as a compact disc (CD), and a long-time playback of the original disk at 13 o'clock.
The present invention relates to a disc playback device with T function.

[Summary of the invention]

The uninvention is that one disc can be played for a long time,
The servo system and mechanism of the disk playback device can be used as is in a normal disk playback device.It can be compressed in 4 ways and prepared with multiple channels and arranged in the time axis direction. The present invention provides a disc remastering device which can reproduce one channel during playback and start the next channel when the channel ends, allowing long-time playback.

[Conventional technology]

Due to device compatibility, the playback time for compact discs and other discs is generally about one hour. Too many discs to play all? I needed it.

[Two problems that the invention is intended to solve] If an autochanger is installed with a large number of disks as described above, it is possible to play for a long time, but it is difficult to play from a position where a large number of disks are missing. A large and complicated device that must be transported to a position where the entire disc can be played? Necessary and Ding 2
There were drawbacks.

[Means to solve all problems]

Non-invention is something that has not been done in view of the drawbacks mentioned above.
Sample data corresponding to multi-channel audio signals are arranged serially in the time axis direction on the original disk, and the serial data of multiple channels is also processed, a synchronization signal is input at a predetermined period, and between the synchronization signals S78, the channels are The first setting of the counting means corresponding to the period is completed, and the channel data corresponding to a given channel is output in a format that is achieved with all the features and the stone disc playback device.

〔Example〕

Hereinafter, one embodiment of the invention will be described with reference to the drawings.

The digital signal sequence in a normal CD is the left and right channels (
The 16-bit data (L% R) is expressed as 4 bytes consisting of 8 bits, and is arranged in the time axis direction. A schematic diagram of this data arrangement is shown in FIG.

That is, usually 44. I KEZ glue, for the sample data for R channel, 44J x 4 = 176.4
A frame synchronization signal S'11 is generated at a constant cycle before and after the B/S data string. Now, if Z is input at the cycle of the frame synchronization signal S i 75 m, the synchronization cycle is 2352 bytes.

The second screen is a schematic diagram showing the data arrangement of a disk used in an uninvented disk playback device. example? Description: This method transmits only the upper significant digits of the sample data, and then separately transmits the shifted ratio value t70 - dengue point data. During playback, the whole reproduced data is transmitted by the amount indicated as the floating point. It is something that is shifted to expand the dynamic range.

On a normal CD, the audio data is processed in 16 bits, and the stones are expressed in 8 bits, and the Froedeng point is 8 bits.
Shift data for bits, that is, 4 bits of data, is O~
The shift amount of 8 bits is shown, and the same dynamic range as 16 bits is obtained. The above-mentioned 70-dengue point data may be made up of several to several tens of samples as the same data, and due to the transmission sound at the maximum level among them, the loss of transmitted bits will be higher than that of the flow-dengue point data. ? By transmitting one transmission per 15 samples of this floating point data, the transmission byte loss of floating point data is reduced.

Moreover, if the 70-dengue point data is lost due to dropout or the like, the audio data of the channel corresponding to 15 samples will be lost, which will cause a serious problem. Therefore, in the present invention, as shown in FIG. The grass has a large width and can handle dropouts. In other words, if the byte error rate is, for example, 10-8, the probability of two errors occurring at the same time is io
The answer is No, meaning that the effects of dropouts etc. can be ignored. Also, the sampling frequency is synchronous signal, 70-
Depending on the dengue point data or the number of channels, it is necessary to reduce the number of D2 as much as possible. For example, if 5 channels are 8 bits, the sampling frequency is fii31.5KE.
IZ and Ding, conventional sampling frequency 44. IK
If the relationship is 7:5 with respect to EIZ, the data D between the synchronization signals S78 is 420 samples, i), 420x
5 = 2160 bytes of data and 420/15 x
4 = 28 x 4 = 112 bytes of floating point data. these? Even if you add it, it will be enough to fit on the disc track. This results in a dynamic range equivalent to 16 bits using 5 channels of floating point data. You can enter the data you have.
oHere, the band is 14KH2, which is sufficient when used for BGM.

Next, FIG. 1 shows a block l' of an uninvented disc playback device.
Show Jk. First, the reproduced data 11 is manually synchronized with the data clock 12 in byte units and then reproduced. This data 11 is subjected to a synchronization pattern detection by the synchronization detector 1, which sets the initial value t of the channel counter 2, and the channel counter 2 operates in synchronization with the data channel. Counter 2 becomes a quinary count. Further, the floating point data is further stored in this 5-ary counter, and 1 is added to the 44 channel counter 2'.
6 counts and synchronizes with the 70-dengue point data position. 40 Next, a channel set switch 13 is provided so that one pulse is emitted every time it is pressed, and this is used to set the channel via the OR gate circuit 15. counter 3
give to

The channel counter 3 is also a quinary counter and counts every pulse.Also, after the disc has been played once, it is played again from the beginning to the beginning, and when it is finished, it returns endlessly, and the return signal at this time is If the channel counter 3 is supplied to the channel counter 3 through 15 14 all-OR gates and is incremented, the channel counter changes every time. By generating pulses only where the value of the counter 3 coincides with the previous channel counter 2 and the seven exclusive ORs by the yoyo-nai matching circuit 4, only the predetermined channel data of the data CD of the plurality of channels shown in FIG. 2 is generated. is latched into register 6 with the addition of data 11.

At this time, the 70-dengue point data is similarly applied to the 70-dengue point data latch circuit 5. If there is an error in the data, in addition to the error 7 lag 16i matching circuit 4 from the normal CD error detection circuit (not shown), the latch data is written twice and transferred to the Froedengbointo data FP. If the first floating point data FP process is correct, it is left as it is and is not latched again.In addition to the shift pulse generation circuit 7, the output of the shift pulse generation circuit 7 is The shift pulse generating circuit 7 increments the counter until the shift value is determined by 470 - the dengue point data and the match value is given to the register 6 to shift this data by a predetermined number of times. If you have a clock counter and use a Kroffke shift clock to match the clock, you can easily obtain the shift clock.So, if you shift 8 bits of data 'fr, 8 bits will have the same range as 16 bits. The data of only one predetermined channel can be selected from the multi-channel serial data.This data is stored in a first-in-first-out memory (FIFO) 8 as a data string with a constant period of 31.5 α and is sent to the digital-to-analog converter D. /A 9 can be used as audio data, and if you record only 4 channels as serial data with 2o, it will be full force, and in the above explanation, if there are 5 channels, there will be 1 empty channel left. The data of the other four channels may be divided into 12 bits each into the channel portion, and each channel may be used as 10 bit floating point data in various ways.

〔Effect of the invention〕

Since the invention is configured and operated as described above, the audio of a predetermined channel is reproduced only at the sound speed of the channel set counter. Also, if you play 5 channels in succession, 5
It has a feature that allows audio data to be played back over time.

[Brief explanation of drawings]

Figure 1 is a system diagram of an uninvented disc playback device, Figure 2 is a schematic diagram of a pattern for recording uninvented serial data and 70-dengue point data, and Figure 3 is a diagram of a conventional CD player. This is a schematic diagram to explain the data format. 1e...Synchronous detector 2.3...Channel callan,
5+ 4... Matching circuit 5... Latch circuit 611.
・Register 7...Shift pulse generation circuit

Claims (3)

[Claims] (1) Arranging sample data corresponding to multi-channel audio signals serially on an optical disk in the time axis direction, and further inputting a synchronization signal at a predetermined period to the serial data of multiple channels, and reproducing the synchronization signal. 1. A disc playback device characterized in that a counting means corresponding to a channel cycle is initialized in a step 100, and channel data corresponding to a predetermined channel is retrieved. (2) Only the predetermined effective bits from the higher order corresponding to the level of the sample data are used as sample data, and the floating point data at this time is allocated to the predetermined sample data, and only the floating point data is on the time axis. 2. The disc playback device according to claim 1, wherein multiple writing is performed at different positions. (3) When the multi-channel serial data has n channels, when writing serial data of channels less than the n channels, write a part of the serial data of other plural channels into the n empty channels. A disc playback device according to claim 1, characterized in that: