JPH0312846A - Recording method for id signal - Google Patents

Abstract

PURPOSE:To record an ID signal with less delay by sharing not only a first level but also a second level smaller than the first level as previously decided levels. CONSTITUTION:A detected recording level L is judged to be in a first state where it is smaller than the previously decided first level L1 or in a second state where the level L is smaller than the second level L2. When either of the first state or the second state continues for prescribed time, start ID are recorded by setting that the recording level L comes more than the first level L1 as a trigger after the first state continues and that the recording level L comes more than the second level L2 as the trigger after the second state continues. Thus, recording without delay is attained by securely adjusting start ID to the starting point of music for recording start ID when recording is executed from recording sources different in noise levels.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ID (identification) signal recording method, and in particular, to an ID (identification) signal recording method, in particular an ID (identification) signal that is added to the beginning of a program such as a DAT (digital audio tape recorder) song. The present invention relates to an ID signal recording method suitable for recording an ID.

(Prior Art) Generally, in a DAT, the beginning of a song is detected and a start ``D'' is recorded. This star ID is recorded for about 9 seconds from the beginning of the song, and the song selection operation is controlled by this start ID during playback and program search. Therefore, the recording position of the start ID is very important.

FIG. 2 is a block diagram of the recording circuit of the AT. As shown in FIG. 2, the audio signal taken in from the input terminal 2 as an analog signal is
The signal is converted into a digital signal by an (analog/digital) converter 4. Next, a signal processing circuit 10 interleaves and adds parity, and the signal is recorded from a recording amplifier 12 through a magnetic head 14 onto a magnetic tape (not shown).

The microcomputer 8 sets the level of the input audio signal to 1'11 through the level detection circuit 6, detects the beginning of the song from this level, and sends a subcode including the static ID to the signal processing circuit 10 for recording. .

FIG. 5 is a flowchart of a conventional ID signal recording method, and FIG. 6 is a timing chart of the conventional ID signal recording method.

As shown in Figure 5, when starting recording, first step S
1 resets the timer. This is to measure the period of silence in the recording source.

Then, in the next step S2, the recording level L is taken in. This recording level L is a certain level, for example -40dB
(when the maximum peak value is OdB) is set as the judgment level, and as shown in Figure 6, if the state is less than -40 dB or continues for 3 seconds or more, this is determined as the inter-song state in step S3 from the timer state. judge. Next, as shown in Figure 6,
When the recording level L reaches 140 dB or more, step S4 determines that this is the beginning of the song, and further step S5
Start recording the start ID. On the other hand, if it is determined in step S6 that the level is -40 dB or more before the timer elapses for 3 seconds or more, it is determined that there is no interval between songs.
The timer is reset in step S7.

(Problems to be Solved by the Invention) Since the conventional ID signal recording method is performed as described above, there are problems as described below.

That is, possible recording sources for DAT include CDs (compact discs), FM broadcasts, microphones, and the like. For example, in the case of a CD, the noise level is -80 dB.
And very small. On the other hand, a typical analog audio cassette has a noise level of about -50 dB, which is very high compared to a CD.

In other words, in the case of a CD, a signal below the noise level of the audio cassette is also a valid audio signal.

Therefore, when determining between songs based on a fixed noise level N, there are problems such as incorrect determination of the intervals depending on the source or a delay in detection. For example, if the noise level N of the input source is larger than the judgment level, it will not be possible to judge between songs, and if the noise level N of the input source is extremely smaller than the judgment level, the level of the input source will gradually decrease. When a program becomes large, a detection delay occurs as shown in FIG. In general, there is a tendency to set a higher determination level in order to prevent the inability to detect between songs. Therefore,
The tendency for detection delays becomes increasingly noticeable. Therefore, when recording the start ID signal, it no longer matches the start point of the program, causing problems such as the starting position of the song after selection.

The present invention has been made in view of the above, and its purpose is to:
An object of the present invention is to provide an ID signal recording method that adaptively and reliably detects the interval between songs for input sources having different noise levels, and enables recording of an ID signal with little delay in response to the start of a program.

(Means for Solving the Problems) The ID signal recording method of the present invention detects a recording level L,
It is determined whether this recording level L is in a first state where it is smaller than a predetermined first level L1 or a second state where it is smaller than a second level L2 which is smaller than the first level L. After the first state or the second state continues for a predetermined time, if the first state continues for a predetermined time, the second state is triggered by the recording level L becoming equal to or higher than the first level level L. If the state continues for a predetermined period of time, the recording level L becomes equal to or higher than the second level 2 as a trigger, and each star 1-I
It is configured to record D.

(Function) Is the detected recording level L in the first state lower than a predetermined first level L1, or in the second state lower than the second level L2, which is lower than the first level L? Determine. When either the first state or the second state continues for a predetermined period of time, after the first state continues, the recording level L becomes equal to or higher than the first level L1 as a trigger; After the state continues, each start ID is recorded using the recording level L becoming equal to or higher than the second level level 2 as a trigger.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a flowchart 1 to 1 for explaining an ID signal recording method according to an embodiment of the present invention. FIGS. 3 and 4 are timing charts in the Il; good recording method of the embodiment.

At the start of recording, first, in step s]1, the first timer and the second timer are reset. In the next step S12, the recording level is taken in. Next, in step 813, the second timer detects whether 3 seconds have elapsed. If 3 seconds have not elapsed, the first timer detects whether 3 seconds have elapsed in the next step S14. If it is determined that the two have not fought for three seconds, then in step S16 it is determined whether the recording level L is 60 dB or more. Here, if the recording level L is 160 dB or more, the second timer is reset in step S17, and the process moves to the next step 318. In step 818, it is determined whether the recording level L is greater than or equal to 140 dB. Here, if it is determined that the recording level L is 140 dB or more, the first timer is reset in step 31.9 and the process returns to step S12. In other words, the start ID is not recorded.

Now, the recording level L is less than -40 dB,
A case in which the condition larger than -60 dB continues will be explained in conjunction with the timing chart of FIG. 4.

If the recording level captured in step S12 is only 40 dB or less, step 318 is reached and the first timer is not reset in step S19, and step S12
Therefore, if this state continues, the first stage will return as shown in Figure 4.
The timer expires 3 seconds. This is detected in step S14, and the recording level L is -40dB in step S15.
A judgment is made as to whether or not the recording level is greater than or equal to 140d.
If it is below B, it is determined that it is still between songs. If the recording level L exceeds -40 dB, it is determined that the song has started, and the process goes to step S21, where the start ID is set to 9.
Record for seconds. In other words, if more than 3 seconds have passed since the recording level dropped to -40dB or less, the recording level will drop to -4[
The start of the song is determined under the condition that the value is 1 dB or more, and the start ID is recorded. At the same time, the first timer is reset because the sequence goes from step 318 to step S19. Next, a case where the recording level L remains lower than 160 dB will be explained. The recording level imported in step S12 is only 16.
If the recording level is below 0 dB, the process goes to step S16 and moves to step S12 without moving to step S17 (without resetting the second timer). However, since the recording level is of course below -40 dB, step 31 Step S1 is performed without resetting the first timer in .9.
Return to 2. Therefore, if this state continues, the second timer will elapse for 3 seconds, but this is detected in step 313, and in step S20 it is determined whether the recording level L is 160 dB or more. And the recording level is only -60.
If it is less than dB, it is determined that it is still between songs. and,
Here, if the recording level L exceeds 160 dB, it is determined that the song has started, the process goes to step S21, and the start ID is
Record for 9 seconds. That is, if more than 3 seconds have passed since the recording level became 160 dB or less, the start of the song is determined and the start ID is recorded on the condition that the recording level becomes 160 dB or more. At the same time, the second timer is reset because the sequence goes from step S16 to step S17. This operation is almost the same as the operation shown in the timing chart of FIG. 4 described above, except that the first and second timers measure time in almost the same way.

Next, a case where the recording level L is lower than 140 dB and then becomes lower than 160 dB will be described in conjunction with the timing chart of FIG. 3. The recording level L imported in step S12 is 14.
If it is 0 dB or less, the process goes to step 318, and without resetting the first timer in step S19,
Return to step S12. As a result, if the first timer has elapsed for 3 seconds, the process moves from step S14 to step S15, and it is determined whether the recording level L is equal to or higher than 40 dB. If the recording level L is not 140 dB or more in step S15, the sequence returns to step S12 through steps S16 and S17 to step 318.

On the other hand, if the first timer has not exceeded 3 seconds, the sequence returns to step S12 via step S16, step S17, and step 818. During this time, the first
The timer continues to measure time. Next, if the recording level further decreases to below -60 dB, this is determined in step S16. Therefore, the second
The process moves to step S12 without resetting the first timer, but since the recording level is of course below -40 dB, the process returns to step S12 without resetting the first timer in step S19. Therefore, if this state continues, the second timer will eventually reach 3 seconds, but
This is detected in step S13 and step S20
It is determined whether the recording level L is 160 dB or more. If the recording level L exceeds 160 dB, it is determined that the song has started, and the process goes to step S21 where the star 1-
Record the ID for 9 seconds. At the same time, the sequence goes from step S16 to step S17, so the second timer is reset, and when the recording level L increases further and exceeds -40 dB, the sequence goes to step 8.
Since the flow changes from step S18 to step S19, the first timer is also reset.

Looking at the above operation in light of the timing charts in Figures 3 and 4, when the recording level L decreases, the system that detects -40 dB or less will first detect this, and if the level becomes even lower. Next, a system that detects -60 dB or less is used to detect this. The first and second timers operate according to the sound level of each recording, and when the sound level is below the judgment level for more than 3 seconds, this is determined to be the beginning of the song. Since the star 1-ID is recorded, a delay in recording the start ID can be prevented.

(Effects of the Invention) As described above, according to the present invention, when recording a start ID based on whether the recording level remains lower than a predetermined level for a predetermined period of time, the predetermined level is set as the predetermined level. In addition to the first level, we also used a smaller second level, so DAT
Even when recording from recording sources with different noise levels, for example, it is possible to reliably detect program breaks, that is, between songs, from the signal level of the source, and when recording the start ID, ensure that this is aligned with the start point of the song. It becomes possible to perform recording without delay.

[Brief explanation of drawings]

FIG. 1 is a flowchart of an ID signal recording method according to an embodiment of the present invention, FIG. 2 is a block diagram of a general AT recording circuit, and FIGS. 3 and 4 are based on the embodiment of FIG. 1. FIG. 5 is a flowchart of a conventional ID signal recording method, and FIG. 6 is a timing chart when the conventional method is implemented. 2...Input terminal, 4...A/D converter, 6...
・Level detection circuit, 8... microcomputer,]
0... Signal processing circuit, 12... Recording amplifier, 14.
...Magnetic head.

Claims (1)

[Claims] A first state in which a recording level L is detected and the recording level L is lower than a predetermined first level L_1, or a second state in which the recording level L is lower than a second level L_2 which is lower than the first level L_1. the first state or the second state.
If the state continues for a predetermined time, and if the first state continues for a predetermined time, the recording level L becomes equal to or higher than the first level L_1 as a trigger, and the second state continues for a predetermined time. After the duration of , the recording level L becomes the second level L_2
Using the above as a trigger, start I
An ID signal recording method characterized by recording D.