JP3254926B2 - Information signal reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reproducing a signal recorded on a magnetic recording medium on which a sound signal is recorded by a rotary magnetic head, or for reproducing a signal recorded on a recording medium such as a magnetic disk or a magneto-optical disk. The present invention relates to an information signal reproducing device for reproducing.

[0002]

2. Description of the Related Art Today, V widely used by general consumers
HS (Video Home System) VTR (Video Tape R)
ecorder) and 8 mm VTR. In these systems, an audio signal and a video signal are recorded on a video tape as a magnetic recording medium by a rotating magnetic head. When performing the reverse reproduction mode by these methods, it is considered that the reproduction is performed by running the recording medium in the reverse direction. Although the video signal in this case is a reproduced image in the reverse reproduction mode, the image content can be recognized to some extent, and thus is output as it is.

However, if the audio signal is output as it is, it is difficult to recognize the content.
It is not output. In the still playback state, the image signal is a still image. However, the audio signal is not output because the rotating magnetic head repeatedly runs on the same track.

[0004]

As described above, in the reverse playback mode of the prior art, no audio signal is output. Then, the use range of the reverse reproduction mode is limited to only the video signal. Further, when an attempt is made to edit while monitoring the reproduced sound or the reproduced image, no audio signal is output in the reverse reproduction mode. For this reason, it was necessary to perform normal reproduction. In addition, when learning using language learning videos, normal playback, or,
When a still state is set in the reverse playback mode, the image becomes a still image. However, no sound is output. For this reason, the same scene cannot be repeatedly learned.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an information signal reproducing device capable of outputting the contents of an audio signal in a reverse reproduction mode so as to be understood. Another object of the present invention is to reproduce a video signal corresponding to an audio signal in the same manner as normal reproduction without causing a lip-sync problem when reproducing in a reverse reproduction mode. An object of the present invention is to provide an information signal reproducing device that can perform editing while editing. It is still another object of the present invention to provide an information signal reproducing apparatus which can output a sound whose contents can be understood even in a still state in either the normal reproduction mode or the reverse reproduction mode.

[0006]

According to the present invention, there is provided an information signal reproducing apparatus for reproducing an information signal from a recording medium on which the information signal is recorded, wherein the information signal includes at least an audio signal and has a reference level on a recording medium. Determination means for determining whether or not the above audio signal is recorded; first storage means for storing a signal equal to or higher than the reference level at predetermined time intervals; and storage means for storing the stored information signal. An information signal reproducing apparatus comprising: an address control unit that can read data in a reverse order.

[0007]

When the reverse reproduction mode is performed, only the sound signal of the sound section is stored at predetermined time intervals. When outputting, reading is performed in the reverse order to the order stored for each time interval. As for the video signal corresponding to the audio signal, the video signal of only the sound section is stored in the same manner as the audio signal. Then, reading is performed in the reverse order of the stored signal so as not to cause the problem of the lip sync with the audio signal. As a result, it is possible to output a sound in which the contents can be understood in the reverse reproduction mode.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a magnetic recording medium such as a magnetic tape. Video signals and audio signals are recorded on the magnetic recording medium. In the reverse reproduction mode, the magnetic recording medium 1
Is driven in the opposite direction. The video signal and the audio signal reproduced from the magnetic recording medium 1 are supplied to a reproduction amplifier circuit 3 via a reproduction head 2 and amplified. The amplified reproduction signal is supplied to the reproduction signal processing circuit 4, where the audio signal and the video signal are processed separately.

The audio signal subjected to the reproduction signal processing is supplied to a sound / non-speech detecting circuit 9 for discriminating between a sound section and a no-sound section. The result of the determination is supplied to the system controller 10. The audio signal subjected to the reproduction signal processing is also supplied to the audio signal memory circuit 6. The memory time input from the time setting input terminal 13 is supplied to the system controller 10 and set. And
Within the set time, the audio signal of the sound section is written to the audio signal memory circuit 6. This write address is sent from the write address generation circuit 7. The write address generation circuit 7 is controlled by the system controller 10.

The video signal processed by the reproduction signal processing circuit 4 is supplied to a video signal memory circuit 5. Then, only the sound section is written according to the write address from the write address generation circuit 7. The audio signal and the video signal written in the audio signal memory circuit 6 and the video signal memory circuit 5
Are read from the audio signal memory circuit 6 and the video signal memory circuit 5, respectively, according to the read address from. The read address generation circuit 8 is controlled by the system controller 10.

The audio signal and the video signal read from the audio signal memory circuit 6 and the video signal memory circuit 5 are:
Audio signal DA conversion circuit 12 and video signal DA conversion circuit 1
1 and D / A converted. The DA-converted signals are output from the audio signal output terminal 15 and the video signal output terminal 14. In the reverse reproduction mode, the read address from the read address generation circuit 8 is generated in the reverse order to the write address over each predetermined time period t0. For this reason, an audio signal similar to the normal reproduction is reproduced every time t0.

FIG. 2 is a conceptual diagram showing a memory time of an audio signal according to an embodiment of the present invention. In FIG. 2, the horizontal axis indicates time, and the vertical axis indicates a reproduced audio signal level. a0
Is a threshold value of a level at which an audio signal is recognized as a silent section. This threshold value a0 is set as a reference level. The audio signal only in the section exceeding the threshold value a0 is written into the audio signal memory circuit 6.

The time for writing to the audio signal memory circuit 6 is set to t0, and the magnetic recording medium 1 is run in the reverse direction. The audio signal in the first section A is equal to or greater than the threshold value a0 over the entire time t0, and is determined to be a sound section. Then, all signals are written to the audio signal memory circuit 6. The audio signal in the next section B is at time t2
Is determined to be a silent section only during the time period, and is written to the audio signal memory circuit 6 only during the time period t1 and the time period t3. That is, in this section B, t0 = t1 + t3. The audio signal in the next section C is the time t in all sections.
It is discriminated that there is a sound section over 0. Then, all audio signals are written into the audio signal memory circuit 6. Only the video signal corresponding to the audio signal written to the audio signal memory circuit 6 is written to the video signal memory circuit 5.

FIG. 3 is a flowchart for explaining the operation of one embodiment of the present invention. It starts from step S1. In the next step, the system controller 1
The memory time of the time setting input terminal 13 is set to 0 (step S2). Then, it is determined whether or not the mode is the reverse reproduction mode (step S3). If the mode is not the reverse reproduction mode, the operation mode is shifted to the operation mode (step S4). In the case of the reverse reproduction mode, it is determined whether the audio signal is sound or no sound (step S5). If there is sound, an address is generated from the write address generation circuit 7 (step S6), and the audio signal is written to the audio signal memory circuit 6 (step S6).
7).

Then, the set time is determined (step S).
8) If it is the set time, the address is stopped to stop writing the audio signal (step S9). In the next step, an address is generated from the read address generation circuit 8 (step S10), and audio is output (step S1).
1). Thereafter, the process returns to step S3 to repeat the above operation. If it is determined in step S5 that there is no sound, the address is stopped and no operation is performed until the sound section starts.

FIG. 4 is a block diagram of a sound / silence detection circuit according to one embodiment of the present invention. FIG. 4A is an example used for an analog audio signal. The analog audio signal input from the input terminal 41 is output to the envelope detection circuit 4.
At 2, the envelope is detected and supplied to the comparator 44. Further, the reference level 43 is supplied to the comparator 44. The presence or absence of the audio signal is determined based on whether the audio signal is higher or lower than the reference level of the comparator 44. The output of the comparator 44 is output to an output terminal 45.
Supplied to

FIG. 4B is an example used for a digital audio signal. In FIG. 4B, a digital audio signal input from an input terminal 51 is supplied to a data comparator 53. The threshold value from the input terminal 52 is supplied to the data comparator 53. Then, the threshold value is compared with the reference level, and the presence or absence of the audio signal is determined based on whether the threshold value is higher or lower. Then, the output of the data comparator 53 is supplied to the output terminal 54.

In one embodiment of the present invention, when other information signals, for example, a video signal are recorded together with the audio signal on the recording medium, the delay time for recording and reading the audio signal is obtained. Only the video signal other than the audio signal is delayed. When the audio signal is read out from the storage unit in the reverse order, the video signal other than the delayed audio signal is also stored in the storage unit at a predetermined time interval, and read out in the reverse order. Also, the audio signal within a preset time is written to the audio signal memory circuit 6. Then, at the time of the still reproduction of the normal reproduction, the audio signal can be repeatedly read out via the audio signal memory circuit 6. During the still playback in the reverse playback mode, the editing operation and the repetitive learning using the language learning video can be performed.

The present invention is not limited to only one embodiment. In the embodiment, a signal reproduced from a magnetic recording medium such as a tape has been described. However, the present invention can be easily applied to a case where a signal is reproduced from a recording medium such as a magneto-optical disk or another solid-state memory.

[0020]

According to the present invention, in the case of performing the reverse reproduction mode, the contents of the audio output, which were conventionally unknown, can be recognized at any time interval desired by the user. In the case of outputting audio in the reverse reproduction mode, the video signal corresponding to the time interval can be reproduced in the same manner as usual without causing a lip-sync problem in accordance with the audio output. Further, in any of the normal reproduction mode and the reverse reproduction mode of the audio signal and the video signal, even in the still state, an audio output whose contents can be understood can be performed. Thereby, it is possible to perform the repetitive learning by the editing operation and the language learning video.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a memory time of an audio signal according to an embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of one embodiment of the present invention.

FIG. 4 is a block diagram of a sound / silence detection circuit according to one embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic recording medium 2 Reproduction head circuit 3 Reproduction amplifier circuit 4 Reproduction signal processing circuit 5 Video signal memory circuit 6 Audio signal memory circuit 7 Write address generation circuit 8 Read address generation circuit 9 Sound / silence detection circuit 10 System controller

Claims (3)

(57) [Claims] 1. An information signal reproducing apparatus for reproducing an information signal from a recording medium on which the information signal is recorded, wherein the information signal includes at least an audio signal, and the audio signal having a reference level or higher on the recording medium. Discriminating means for discriminating whether or not the information signal is recorded; first storing means for storing a signal equal to or higher than the reference level at predetermined time intervals; and an order of storing the stored information signal. An information signal reproducing device comprising: an address control unit that can read data in the opposite direction. 2. The second storage means, wherein the information signal includes an audio signal and other information signals, and the information signal other than the audio signal is delayed by a time delayed for storing and reading the audio signal. Wherein the address control means stores the audio signal in the first storage means at predetermined time intervals, and when the address signal is read out in the reverse order, the information signal other than the audio signal 2. An information signal reproducing apparatus according to claim 1, wherein said information is also stored in said second storage means at said predetermined time interval, and is controlled so as to be read out in an order reverse to that order. Wherein said address control means, when the scan chill reproduction, claim 1, characterized in that as repeatedly read out the audio signal stored in said first memory means
And an information signal reproducing apparatus according to claim 2.