JP2687400B2 - Playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] According to the present invention, an information signal compressed at an arbitrary compression rate is added with a section designating signal indicating the start and end of the information signal. The present invention relates to a reproducing device for reproducing the information signal from a recording medium recorded together with data indicating the rate.

[Conventional technology]

As a device for reproducing from a medium on which time-axis-compressed information is recorded, for example, a disc-shaped recording medium capable of recording an audio signal together with a video signal, a reproducing device for reproducing from a so-called video floppy is known as an example. .
When a video floppy is loaded, the conventional video floppy playback device with audio playback function starts playback from the audio head address contained in the code according to the control code of the audio track, and then follows the continuous audio subsequent address. The track is moved and the audio is played back sequentially.

[Problems to be solved by the invention]

But as long as you follow these audio playback procedures,
In order to know the time amount of the audio signal recorded on one video floppy (that is, the audio reproduction time), it is very inconvenient to play one audio track.

For example, a method of estimating the audio reproduction time from the number of audio tracks can be considered, but if the audio recording is completed in the middle of the track, that amount becomes an error. In the case of a large number of voice sequences, the error will be accumulated and thus the detected voice reproduction time will be very inaccurate.

Such a problem is not limited to a device using a disc-shaped recording medium such as the still video described above, but is a problem similarly occurring in a device using any medium.

Therefore, the present invention can automatically calculate the amount of information indicated by the information signal that is compressed at an arbitrary compression rate and recorded on the recording medium, without requiring a complicated operation, and the information indicated by the information signal can be calculated. It is an object of the present invention to provide a reproducing apparatus capable of quickly and accurately knowing the amount of the.

[Means for solving the problem]

The reproducing apparatus according to the present invention is a recording in which an information signal compressed at an arbitrary compression rate is added with a section designating signal indicating the start and end of the information signal and is recorded together with data indicating the compression rate. A device for reproducing the information signal from a medium, wherein the section indicating signal and the data indicating the compression rate are detected from the signal reproduced from the recording medium, and the detection timing of the section indicating signal and the detected data. According to the compression ratio indicated by the calculation means for calculating the amount of the information signal in the section indicated by the section indication signal, and the information signal reproduced from the recording medium according to the calculation result in the calculation means. Signal generating means for outputting a signal indicating the amount of information indicated by.

[Action]

By the means described above, the amount of information indicated by the information signal compressed at an arbitrary compression rate and recorded on the recording medium can be grasped quickly and accurately without requiring a complicated operation.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

In FIG. 1, 10 is a system controller, 12 is a magnetic disk 12, 14 as a recording medium, a reproducing head, 16
Is a spindle motor for rotating the magnetic disk 12, 18
Is a sensor for detecting the PG yoke of the magnetic disk, 19 is a preamplifier, 20 is an FM demodulation circuit, 22 is a de-emphasis circuit,
Reference numeral 26 denotes a video reproduction circuit that outputs a standard television signal. 28 is an audio signal de-emphasis circuit, 30 is an A / D converter, 32 is an audio memory, 34 is a D / A converter, and 36 is an / A converter 3
It is a decoder that decodes the analog output of 4 and performs noise reduction processing. 38 is a flag detection circuit for detecting a start flag and a stop flag, 40 is a control code detection circuit for detecting a control code, 42
Is the address for outputting the write address signal of the audio memory.
A counter, 44 is an address counter that outputs a read address signal of the audio memory, 46 is a timing signal generation circuit that outputs various timing signals in accordance with the rotation phase signal from the sensor 18, and 48 is a variable for arithmetic operation. Memory, 50 and 52 are oscillators, 54 is a sync separation circuit that separates the sync signal from the output of the video reproduction circuit 26, 56 is a display device for visual display, and 58 is a switch for inputting various instructions. . Reference numeral 60 denotes a head drive circuit that moves the head 14 in the radial direction of the magnetic disk 12.

The operation will be described with reference to FIGS. 2, 3, and 4. After the initialization (S1) is completed, the system controller 10 waits for the magnetic disk 12 to be loaded (S2). After the loading, the spindle motor 16 is rotated to drive the magnetic head drive circuit 60.
The magnetic head 14 is moved to a designated track position on the magnetic disk 12 (S3). The output of the head 14 is the preamplifier 19
Is applied to the FM demodulation circuit 20 via and is FM demodulated. The video signal in the output of the FM demodulation circuit 20 is a de-emphasis circuit
It is supplied to the video reproduction circuit 26 via 22. Video playback circuit
26 performs a known video reproduction process and outputs a video signal.
On the other hand, signals other than the video signal in the output of the FM demodulation circuit 20 are applied to the A / D converter 30, the flag detection circuit 38, and the control code detection circuit 40 via the de-emphasis circuit 28.

At this stage, the audio reproduction time measurement routine (S4 and third
(Fig.), The system controller 10 sets the voice sector number to # 0 (S31), and the address counter 42
The data pointer value of is set to 0 (S32). The audio recording track is composed of four sectors # 0, # 1, # 2, and # 3, and the sectors are recorded in order from the PG yoke that serves as a reference for one rotation. The position of the PG yoke can be detected by the sensor 18, and the timing signal generation circuit
46 applies the PG signal to the system controller 10 according to the detection signal from the sensor 18. The system controller 10 receives the start flag signal and the end flag signal from the flag detection circuit 38 on the basis of the PG signal, and outputs a control signal for an operation described later to the address counter 42. The start flag signal output from the flag detection circuit 38 is also applied to the control code detection circuit 40.

Now, the system controller 10 designates the sector to be reproduced to the timing signal generating circuit 46 according to the PG signal from the timing signal generating circuit 46 (S3
3). When the flag detection circuit 38 detects the start flag, it outputs a start flag signal to the system controller 10. When the start flag signal is not output from the flag detection circuit 38 for the designated sector, the system controller 10 ends the audio reproduction time measurement routine (Fig. 3) (S34) and outputs the start flag signal. Control code detection circuit
40 searches for a control code according to the start flag signal output from the flag detection circuit 38 (S35). If the control code cannot be detected, the measurement routine is similarly ended.

On the other hand, the timing signal generating circuit 46 is the flag detecting circuit 38.
Address counter depending on the start flag signal of
A start signal for instructing the start of counting is applied to 42. A / D
The converter 30 digitizes the input audio signal according to the clock pulses from the oscillator 50. The output of the A / D converter 30 is
It is written in the voice memory 32 under the address control of the address counter 42 (S36). Address counter 5
At 0, the same clock as for the A / D converter 30
Applied from 50. The writing to the voice memory 32 is continued until the flag detection circuit 38 detects the end flag and the timing signal generation circuit 46 instructs the address counter 42 to stop counting (S37).

When the writing to the audio memory 32 is completed, the system controller 10 determines the recording type of the sector that is being reproduced, based on the polarities of the start flag and the end flag. Type 1 shows the case where recording continues in the next sector of the same track, type 2 shows the case where recording continues in sector # 0 of the following track, type 3 shows the end of the audio sequence, and type 4 shows the unused state. Indicates that there is. Therefore, the routine is divided into the following routines according to the type of the end flag (S38). In the case of type 4, it is judged whether or not this sector is sector # 0 which is the head of the track (S41). If it is sector # 0, the measurement is terminated and sector # 0
If not, the voice compression rate is known from the control code, the number of data per second at the time of voice reproduction is obtained, and stored in the memory 48 together with the data pointer value of the address counter 42, and the measurement routine of FIG. Ends (S42).
When it is determined to be the type 3, similarly, the number of data per second and the data pointer value are stored in the memory 48 (S42). If it is determined to be type 1 or type 2, it is determined whether or not this sector is sector # 3 (S39), and if it is sector # 3, go to S42 and end the measurement, except for sector # 3. If so, move up the sector number
Return to S33 and continue measurement (S40).

When the measurement of the audio reproduction time for one audio track is completed, the system controller 10 determines whether or not to measure the next track (S5). If the measurement is continued, the track is moved (S3). If the measurement is not continued, it is checked whether the display switch included in the switch group 58 is on or off (S6). If the display switch is off, the display operation is not performed and the operation ends, but if the display switch is on,
Set the display mode (S7). As the display mode,
For example, total time display that displays the total playback time of the audio signal recorded on one video floppy, sequence time display that displays the total time of the specified audio sequence, and total playback of each sequence for all audio sequences. All sequence time display that displays time sequentially or simultaneously, track time display that displays the audio playback time of a specified track, and total audio playback time when the audio corresponding to a video track spans several tracks It is possible to display video and time.

After setting the display mode as described above (S7), the display operation is performed (S8). Details of this display operation are shown in FIG. After initialization (S50), the system controller 10 specifies the read address of the memory 48 according to the display mode setting (S51), and sets the necessary data pointer value for each track and data per second. Read the number. The system controller 10 substitutes the data pointer value into the variable C and substitutes the number of data per second into the variable D (S52). However, since C contains pedestal, control code, and overlap in addition to the actual data, these are substituted into variable E, and the calculation of B = B + (CE) is performed as the integration. (S53). If the data of the next track is also added according to the display mode, the process returns to step S51. If not, the audio reproduction time is obtained by the calculation of A = B / D (S55), and the result A is stored in the memory 48. Yes (S56).
The above processing is repeated until the data required for display is obtained (S57). The calculation result A of step S55 is sequentially stored in the memory 48, and the calculation result A is sequentially transferred to the display device 56 (S58) and displayed (S59). The display device 56 is, for example, a display device using an LCD or LED. This display is performed and a series of operations is completed.

Since the data pointer value for each track and the number of data per second are stored in the memory 48, re-display or display in a different display mode is possible even after the operation is completed. When the display device 56 has a memory for storing display data, the display data can be redisplayed regardless of the storage of the memory 48.

FIGS. 5 and 6 are flowcharts of a modified embodiment in which the operations of FIGS. 3 and 4 are changed, FIG. 5 shows a voice reproduction measurement routine, and FIG. 6 shows a display routine.
The same parts as those in the corresponding flows of FIGS. 3 and 4 are designated by the same reference numerals. According to the video floppy standard, there is a pedestal, a control code and an overlap code section between the start flag and the audio data, and a predetermined length is provided between the audio data and the end flag. Sano's pedestal is prescribed.
In the flowchart of FIG. 3, the number of data including them in the voice data is stored in the memory 48, but in this modified embodiment, these code portions are excluded in advance as the number of data to be stored in the memory 48.

In the measurement routine of FIG. 5, similarly to FIG. 3, the process proceeds to steps S31 to S35, and after step S35, the voice memory 32
Prior to writing to the address counter, the data pointer value of the address counter is subtracted by the number corresponding to the above code portion between the start flag and the voice data (S60). Upon receiving the start flag signal from the flag detection circuit 38, the timing signal generation circuit 46 receives the address counter 42.
The count start signal is supplied to. The output of the A / D converter 30 is written to the address of the audio memory 32 according to the data pointer value of the address counter 42 (S3
6). Since the data pointer value is subtracted in step S60, the audio data is written from address 0. Writing to the voice memory 32 is continued until the end flag is detected, as in the case of FIG. 3 (S37). When the writing is completed, the system controller 10 subtracts the data pointer value held by the address counter 42 by the number of data corresponding to the pedestal existing between the voice data and the end flag (S61). After that, the process proceeds in the same manner as in the case of FIG. Therefore, the memory 48 stores purely the number of audio data.

As described above, when the number of audio data is stored in the memory 48 as it is, the subtraction in step S53 of FIG. 4 is not necessary. Therefore, if the subtraction of E is not performed and the C is simply integrated. Well, specifically, step S53 in FIG. 4 may be changed to step S62 in FIG.

Although the still video reproducing apparatus has been described as an example in the above embodiment, the present invention may be a tape recording medium, a disk recording medium, or a solid-state memory such as a semiconductor memory. Further, the information to be recorded is not limited to voice, but may be other information.

〔The invention's effect〕

As described above, according to the present invention, it is possible to automatically calculate the amount of information indicated by an information signal which is compressed at an arbitrary compression rate and recorded on a recording medium without requiring a complicated operation. Therefore, it is possible to provide a reproducing apparatus capable of promptly and accurately knowing the amount of information indicated by the information signal in various notification modes.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a basic flowchart of FIG. 1, FIG. 3 is a detailed flowchart of a reproduction time measuring routine of FIG. 2, and FIG.
5 is a detailed flowchart of the display routine shown in FIG. 5, FIG. 5 is a modified example of the reproduction time measurement routine, and FIG. 6 is a flowchart of the display routine corresponding to FIG. 10 ... System controller, 12 ... Video floppy, 14 ... Playback head, 16 ... Spindle motor,
18 …… PG sensor, 19 …… Preamplifier

Claims (2)

(57) [Claims] 1. An information signal compressed at an arbitrary compression rate is added with a section designating signal indicating the start and end of the information signal, and is recorded together with data indicating the compression rate from a recording medium. A device for reproducing an information signal, which detects the section indicating signal and data indicating the compression rate from a signal reproduced from the recording medium, and detects the detection timing of the section indicating signal and the compression indicated by the detected data. The information indicating the information signal reproduced from the recording medium according to the calculation result of the calculation means by the calculation means for calculating the amount of the information signal in the section indicated by the section indication signal. And a signal generating means for outputting a signal indicating the amount of the reproduction amount. 2. A reproducing apparatus according to claim 1, wherein the information signal is an audio signal.