JPH06181560A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a recording and reproducing device capable of easily retriev ing information. CONSTITUTION:A main memory 18 consisting of a solid-state storage element is used as a recording medium, compressed sound data, compressed video data and retrieving ID data outputted from an ID generating circuit 12 are synthesized by a data synthesizing circuit 13 to constitute a data block and each data block is stored in the memory 18. At the time of retrieval, sound data or video data are read out based upon the ID data and extended and the restored sound data or video data are monitored. Thereby data can quickly be retrieved without executing fast forward or rewinding operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for recording and reproducing video information and audio information.

[0002]

2. Description of the Related Art Conventionally, when recording and reproducing a moving image signal, a so-called VTR (video tape recorder) using a magnetic tape having a tape width of 1/2 inch or 8 mm is generally used as a recording medium. is there.

The VTR is for recording / reproducing video information of one field on one track on a magnetic tape wound on a rotary drum by a rotary head provided on the rotary drum. In the case of performing image retrieval, that is, so-called cueing, with such a VTR, recorded video information is used by using functions such as fast-forwarding, rewinding control, special reproduction, etc. using an index signal for cueing a video scene I try to do the search work while actually playing.

[0004]

When a conventional VTR is used for retrieval, since the video signal is recorded on a tape-shaped recording medium, it takes time to transfer the tape to retrieve the desired video. In some cases, the search work required a great deal of time and effort.

Further, during the search operation, since the rotary head always traces the tape while hitting it, the reliability of the recorded information may be affected due to abrasion or damage of the tape.

Further, when the VTR is a recording system using an analog signal, the retrieved information is copied to another medium.
Then, there is a problem that image quality is deteriorated by so-called dubbing.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a recording / reproducing apparatus which uses a solid-state memory element as a recording medium and which can be searched easily and efficiently. I am trying.

[0008]

In the present invention, a solid-state storage element is used as a recording medium, video information, audio information, and search information of these two pieces of information are associated with a minimum storage unit, and the storage unit is associated with the minimum storage unit. Each time the information is stored in the solid-state storage element and information is searched for, the search speed is made variable according to the state of the audio information or the video information based on the stored search information.

[0009]

The retrieval by the audio monitor or the video monitor can be performed in a short time without performing the fast-forwarding or rewinding of the recording medium as in the conventional case.

[0010]

1 shows an embodiment of a recording / reproducing apparatus according to the present invention.

In FIG. 1, reference numerals 1 and 2 denote L and R channel audio signal (audio signal) input terminals, 3 denotes a video signal (video signal) input terminal, and 4 and 5 denote L and R channel audio signals as digital signals. AD converter to convert, 6
Is an AD converter for converting a video signal into a digital signal, 7 and 8 are audio signal processing circuits for performing predetermined processing on the digital audio signal, 9 is a video signal processing circuit for performing predetermined processing on the digital video signal, and 10 is processed. An audio data compression circuit for compressing L and R channel audio data, and a video data compression circuit 11 for compressing the processed video data.

Reference numeral 12 denotes I for creating search information (ID data) for search based on time code, memory information, etc. described later.
D generation circuit, 13 is a data synthesizing circuit for creating a data block for each ID data from compressed audio data, compressed video data and ID data, and 18 is a main memory as a recording medium for recording the data block. Yes, it is composed of a solid-state memory element.

Reference numeral 17 is a memory controller for controlling reading / writing of the main memory 18, 16 is a system controller for controlling the memory controller 17 and the entire apparatus, and 14 is a time code such as year / month / day / hour / minute / second. Is a calendar clock generating circuit, 15 is a memory information generating circuit for generating memory information indicating the amount of data and the like, 19 is an operation key operated by a user, and 20 is a display device for performing necessary display such as an operation mode.

Reference numeral 21 is a data distribution circuit for distributing the data blocks read from the main memory 18, reference numeral 22 is a search information reproduction circuit for reproducing an ID from the distributed data,
Reference numeral 23 is a display information generating circuit for generating display information from ID data, 24 is a video data expanding circuit for expanding the distributed compressed video data, and 25 is an audio data expanding circuit for expanding the distributed compressed audio data. , 26
Is a data selection circuit for synchronously selecting each expanded data.

Reference numeral 27 is an adder for adding the display information and the selected video information, 28 is a DA converter for converting the added output into an analog signal, 30 is a video monitor for monitoring the video signal, and 29 is selected. A DA converter for converting voice data into an analog signal, and 31 is a voice monitor for monitoring the voice signal.

Reference numeral 32 is an output terminal for video data, 33 is an output terminal for audio data, 34 is a silent section detector for detecting a silent period from the audio data and informing the system controller 16, 35 is a motion detector for detecting the motion from the video data. System
This is a motion detector that informs the controller 16.

Here, the main memory 18 using a solid-state storage element as a recording medium will be described.

In recent years, the progress of semiconductor technology has been remarkable, and looking at the trend of the degree of semiconductor integration, the memory capacity is increasing at a rate of four times in a cycle of about three years. On the other hand, various compression methods for compressing information have been proposed. In addition, the price of semiconductors tends to drop dramatically due to the effects of mass production. Considering these points, the semiconductor memory, which has been able to write only still images, can store moving images, and can be put to practical use as a recording medium of a recording / reproducing apparatus.

According to the present invention, the main memory 18 is constructed by using a large capacity solid-state memory element made by the latest semiconductor technology.
In addition, a moving image is stored using a high-efficiency compression method, and when performing a variable speed search or editing, video information, audio information, and search information are used as a data block of a minimum storage unit,
By writing in the solid-state memory device, operability during editing,
In addition to speeding up the search, the limited memory area is efficiently occupied by address management of the memory.

Next, the operation of the configuration shown in FIG. 1 will be described for recording and reproducing.

First, the recording operation of this embodiment will be described. Left (L) and right (R) from the audio signal input terminals 1 and 2, respectively
A channel stereo audio signal is input and converted into a digital audio signal by the AD converters 4 and 5. The digital audio signal is subjected to various noise removal and dynamic range limitation processing by the audio signal processing circuits 7 and 8, respectively, and then the audio data compression circuit 10 performs data compression processing.

This data compression processing is performed by, for example, MPEG.
Adaptive transform coding (ATAC, ASPEC) proposed by (Moving Picture Expert Group), band division coding (MUSICAM, SB / ADPCM), or the like may be used, or L / R correlation is used. Channel-mixed vector coding or the like may be used.

On the other hand, the video signal input from the video signal input terminal 3 is converted into a digital video signal by the AD converter 6 capable of processing at a higher speed than the AD converters 4 and 5. A video data compression circuit 11 compresses the data amount of this digital video signal to about several tens to several hundreds. This compression processing includes inter-frame correlation using image correlation between frames, motion vector compensation for reducing the image quality deterioration in the above method, and bi-directional prediction frames that perform this before and after (past and future) on the time axis. It can be realized by appropriately combining inter-compression and the like. As an example, an algorithm proposed by MPEG, commonly called MPEG-
With I, it is possible to ensure a standard image quality of a so-called 1/2 inch VTR.

Next, the ID from the ID generation circuit 12 described later.
The data synthesizer 13 synthesizes the data with the compressed audio data and video data, and the main memory 18
Store to.

The main memory 18 is controlled by the memory controller 17 such as memory address and writing / reading. The main memory 18 is a large-capacity solid-state memory circuit composed of flash memory, DRAM, SRAM and the like.

Further, the memory controller 17 is controlled by the system controller 16, and the system controller 16 externally controls the operation of the apparatus as a whole. That is, the system controller 1
An operation key 19 is used to input an instruction such as recording / playback / search, and the memory controller 17 is controlled in response to the instruction. At the same time, information such as an operation status of the apparatus and a time code indicating the recording / playback time is displayed. Is displayed on the display device 20, and the memory information generation circuit 15 is also notified of the time code and the like.

There are two main types of this time code. The first is the elapsed time from the beginning of the main memory 18 or the video program and the accumulated time of camera photographing, and the second is the date information of recording or camera photographing. A calendar clock generation circuit 14 for generating the latter time code is provided.

The memory information generation circuit 15 receives data such as the information storage status from the memory controller 17, and supplies it to the ID generation circuit 12 as memory information indicating the amount of recorded information.

As the contents of this memory information, for example,
Time code based on information from the system controller 16, data indicating mode selection of image quality and sound quality, and data amount of video and audio based on information from the memory controller 17 (data length in the case of variable length coding) And the start address value of data storage on the memory.

The ID generating circuit 12 creates ID data from these data and the data from the system controller 16 and transfers it to the data synthesizing circuit 13. The data synthesizing circuit 13 forms a data block from the ID data and the compressed audio data and video data. Then, the data blocks for each ID are sequentially stored in the main memory 18. Further, the head address of the main memory 18 is sequentially written into the ID file set in the main memory 18.

FIG. 2 shows an example of data storage in the memory 18 and a data format of a data block.

The upper part of FIG. 2 shows a state in which the horizontal axis is the time axis and the ID data is generated at every predetermined period T ₀ .

In the center of FIG. 2, a conceptual diagram of the address space of the main memory 18 is shown. After the ID data, video and audio information data having different data amounts are sequentially stored for each processing period by variable length coding. Therefore, the ID data are generated at regular intervals T ₀ (for example, 1 second), but they are not at regular intervals on the memory as illustrated.

Therefore, in order to enable quick access to the data block at the time of retrieval, an ID file in which the addresses indicating the storage locations of the data blocks are collected is generated as shown in the upper part of FIG. This ID file stores only the head address of the data block in a predetermined area according to the storage capacity of the main memory 18.

The ID data in the data block has a fixed length, and has a total of eight types of basic information in the example of FIG. That is, it has data for selecting a mode of image quality and sound quality by the trade-off between the time code and recording time according to SMPTE, the start address of the variable-length AV data, the data amount, and the deleted flag.

The deleted flag is a logical erased state that can be restored before the physical delete process when the recorded data is erased, and this flag prohibits normal reproduction.

The audio data is composed of initialization information (reset data) for each of the L and R channels and variable-length compressed audio data that has been compressed. The video data is composed of, for example, an initialization screen (video reset data) by intra-frame coding and the like, and compressed video data variable-length coded by various compression methods.

For each ID data, one set of the video data and the audio data having the above-mentioned configuration constitutes a data block. This data block is characterized in that it is generated at intervals T ₀ defined on the time axis.

FIG. 3 shows an example of the video signal. In this example, a TV signal having a horizontally long aspect ratio (9:16) with an aspect ratio close to that of a video screen is used as an input signal on the basis of an NTSC (525 vertical) TV signal. Assuming that the effective rate of this screen is 94% vertically and horizontally, 495 x 880
Pixel information is generated for 30 screens per second, and the input terminal 3 of FIG.
Is supplied to.

This composite video signal is converted into digital data by the AD converter 6, and then the video signal processing circuit 9 optionally uses a component (for example, Y: R).
-Y: BY = 4: 2: 2). Here, the luminance (Y) per pixel is 8 bits, and the color difference is 1 /
When 8 bit quantization is performed at a sampling rate of 2, it becomes about 700 Gbit per hour.

Incidentally, 48 kHz / 1 of a stereo audio signal
Approximately 5.5 Gbi per hour with 6-bit digitization
When the compression processing described above is applied to this, the total AV becomes about 4 Gbit.

The reproducing operation of this embodiment will be described below. When the reproducing operation is instructed by the reproducing key included in the operation keys 19, the system controller 16 causes the display device 2 to operate.
A message indicating that the playback operation is in progress is displayed at 0, and the memory controller 1
The memory address and read / write are controlled by 7 to read the information stored by the above-described recording operation from the main memory 18.

A predetermined amount of information is read out per unit time based on the ID data. In the example above, 3 per second
There are 0 screen image information, 1 second stereo (or 2 channel) audio information, and ID data for searching these.

The above three types of data are supplied to the data distribution circuit 21 in a mixed state (serial data information).
According to this data form, it is possible to add the main memory 18 or adopt a replaceable memory form such as an IC card.

The data distribution circuit 21 distributes data as follows.

The ID data is added to the search information reproducing circuit 22 to detect the information as shown in FIG. 2 for each ID, and the display information for the monitor is displayed from this information.
3 is combined with the video information generated in step 3 and restored by the adder 27, converted into a versatile analog signal by the DA converter 28, and displayed on the video monitor 30.

The video data is subjected to a data decompression process which is the reverse of the compression process at the time of recording in the video data decompression circuit 24,
Reconstructs a video signal equivalent to the input signal during recording. Then, the data selection circuit 26 outputs the data to be supplied to the adder 27 for synthesizing the display signal for the reproduction monitor and the video data output terminal 32.

The audio data is the audio data expansion circuit 2
In 5, the same data compression processing as that of the video data and a data decompression processing opposite to that at the time of recording are performed to reproduce an audio signal equivalent to the input signal at the time of recording. DA converter 2 for generating an audio signal for audio monitoring from the data selection circuit 26
9 and the data to be supplied to the audio data output terminal 33.

For each of the video and audio data, the above-mentioned ID data is used to correct the deviation due to the delay time required for the reproduction signal processing and reproduce. In addition, in synchronization with the information from the display information generation circuit 23, the respective reproduction signals of video and audio are output from the data selection circuit 26.

Further, the silent part detector 34 for discriminating the magnitude of the amount of voice information outputs the judgment result of the silence or the voice to the system controller 16. The motion detector 35 detects the motion by detecting the difference amount between the original frame of the image information and the image of the frame immediately before the original frame, and outputs the determination result to the system controller 16.

Next, the operation for searching for audio and video will be described with reference to the flowchart of FIG.

When the search mode switch included in the operation key 19 is operated, the flow starts. Step S
At 1, it is determined whether the voice search mode is set. If it is a voice search, the process proceeds to step S2, and it is determined whether the voice search switch included in the operation key 19 is turned on. If it is not turned on, the process returns to step S1. If the voice search switch is turned on, the process proceeds to step S3 to read voice data from the main memory 18.

In step S4, a counter (hereinafter referred to as CNT) included in the system controller 16 is reset. In step S5, it is determined whether the voice data read in step S3 is silent. If there is no sound, the process proceeds to step S6, and the data is read from the main memory 18 under the control of the memory controller 17 at a reading speed N + α times the normal speed.

In step S7, the CNT is operated to measure the time during the search for the silent portion, and in step S8, it is determined whether or not the voice search switch is turned off.
While the voice data is silent, the loop process of steps S5, S6 and S7 is performed.

When the voice is turned from silence in step S5, the above loop is exited, and the process proceeds to step S9. In step S9, it is determined whether or not the value of CNT is equal to or larger than a predetermined value M.
If the value of CNT is greater than or equal to the predetermined value M, step S10
Proceed to and perform N-α double speed search. That is, the speed is reduced by α times the speed of the N times speed search, and the intelligible voice is reproduced.

In step S11, a timer that defines the time during which the N-α double speed search is performed, and this loop is circulated until the timer times out (step S13) or a silent portion is detected (step S12). To be done. The time of the timer is a value determined by the value of CNT.

If the period of the silent portion is shorter than the reference value M in step S9, or if the timer counts over in step S13, the process proceeds to step S14 when the timer of the voiced portion ends, and N-speed search is performed. . In step S15, it is determined whether the voice search switch has been turned off. If not turned off, step S1
Returning to step 2, the loop process of steps S12 to S15 is performed.

Next, when it is determined in step S1 that the voice search mode is not set, the process proceeds to step S16, and it is determined whether or not the video search switch is turned on. ON
If not, the process returns to step S1, and if it is turned on, the process proceeds to step S17 to read the video data from the main memory 18.

In step S18, the process proceeds to any of the three steps S19, S20 and S21 according to the output signal of the motion detector 35. The motion detector 35 compares adjacent frame images of the video signal, and if the difference is large, determines that the moving image is a moving image, and conversely, if the change is small, determines that the image is a still image. As a result of this determination, if the movement is small, the process proceeds to step S19, and the speed becomes α faster than the N times speed. If the amount of change is medium, the process proceeds to step S20, and the speed is N times the speed. If the amount of change is very large, the search is slower by α than the N speed in step S21. Until the video search switch is turned off,
The loop process of steps S18 to S21 is performed.

It is to be noted that the motion detector 35 is made to judge by the integrated amount of a certain period, and a person who has a threshold level like a window comparator looks at the monitor when judging the switching between large, medium and small. The result is a stable search image.

Next, in the case of voice search, a timer skip voice search for performing voice reproduction at regular time intervals will be described.
The timer skip voice search will be described with reference to FIG. In FIG. 5A, the horizontal axis represents time and the vertical axis represents the level of the audio signal. FIG. 5B shows a period during which the voice is extracted when the voice of the voice signal is searched.

In this embodiment, the search period is performed at a constant interval (= M), and the period for extracting the voice in this M is N. The voice search speed is the normal M / N speed.

Since voice information exists from 0 in the first period of 0 to I, the timing of voice search starts from 0, and N is extracted and provided. Next search period I ~
In II, there is no voice information at the start of I, so
The voice is shifted to a certain point A, and the voice is extracted from the point A for a period of N and output as voice information.

Similarly, in the periods II to III, the voice is extracted and output up to the period N starting from the point B where the voice information exists. The presence / absence of sound is detected by the silence detector 34, and the result of the presence / absence of the sound is detected by the system controller 16
Then, the internal programs generate search periods M and N.

Next, a method of generating the search periods M and N will be described with reference to the flowchart of FIG.

The flow starts when the voice search mode switch is operated. In step S31, the GATE flag is reset. In step S32, the counter P is reset.

Next, in step S33, the presence or absence of a voice signal is determined by the silence detector 34, and if there is no sound, the process proceeds to step S34. Here, as described above, M indicates a constant search interval, and N indicates a period during which voice is extracted. It is checked whether (M−N) is larger than the counter P, and if it is larger, step S3.
At 5, the counter P is operated to count the silent period.
The flow up to this point is a flow for preventing the voice extraction period N from exceeding the voice search period M in FIG.

This loop is repeated until the value of the counter P becomes larger than (MN) or the voice signal becomes voiced. If either of these two conditions is satisfied, the process proceeds to step S36 and the flag GATE is set. In step S37, the counter L is reset, and in step S38 it is checked whether the GATE flag is set. If GATE is 1, the process proceeds to step S39.

In step S39, the counter L is operated. In step S40, the value of the counter L is compared with the constant N, and if the value of the counter L is larger than the constant N, the process proceeds to step S41. The flow up to this point is the flow for generating a pulse in the voice extraction period N of FIG.

When the counter L becomes the same as the voice search period N, the flow advances to step S41 to reset the GATE flag. That is, the period during which GATE is High is the voice search period N.

In step S42, the counter P is operated when it is not operating. In step S43, the value of the counter P is compared with the constant M, and if the value of P is large, step S
Returning to step 31, if the value of P is small, return to step S38. As a result, one cycle of the search period M shown in FIG. 5 is created.

If the flag GATE is "0" in step S38, the route jumping to step S42 ends the voice extraction period N and makes time until the voice search period M. Of course, when the voice search switch is turned off, each processing of the flow of FIG. 6 is stopped.

[0073]

As described above, according to the present invention, the solid-state storage element is used to record the audio information, the video information, and the search information in data block units, and at the time of the search, the audio information or the video information. Since the search speed is changed according to the information, it is possible to record and reproduce video and audio without using any mechanical member, and thus it is possible to obtain a device having excellent information searchability. Is obtained.

In the voice search mode, the voiced portion is searched at N times speed, the silent portion is searched at a speed faster than N times speed, and the voiced portion after the silent portion is continued for a certain time is faster than N times speed. By making it slow, it is possible to quickly skip a portion having a small amount of information, such as a silent portion, and perform an effective search only in a portion where a voice exists, so that effective information can be retrieved quickly.

In the case of video search, a still image with little motion is searched at a speed faster than N times speed, and a video with a lot of motion is searched at a speed slower than N times speed. This has the effect of quickly skipping over the points and concentrating only effective images such as images with fast movements.

Further, in the voice search, if the time skip for reproducing the information is performed at regular intervals, a portion such as a silent portion is shifted and only a portion having information is extracted, so that a more efficient retrieval can be performed. It can be carried out. Further, it is possible to obtain the effect that the signal quality does not deteriorate even if a copy is taken.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram showing a data storage state in a main memory.

FIG. 3 is a configuration diagram of a television screen for explaining a video signal.

FIG. 4 is a flowchart showing a search operation of audio information and video information.

FIG. 5 is a timing chart showing a timer skip voice search operation.

6 is a flowchart showing a search operation of the voice information of FIG.

[Explanation of symbols]

 10 audio data compression circuit 11 video data compression circuit 13 data synthesis circuit 16 system controller 17 memory controller 18 main memory 24 video data expansion circuit 25 audio data expansion circuit 30 video monitor 31 audio monitor

Claims (4)

[Claims] 1. A recording unit that associates video information, audio information, and search information for searching these two pieces of information with each other to form a storage unit and sequentially records the storage unit on a recording medium. When the information is searched, the audio information or the video information is read from the recording medium based on the search information to reproduce the audio signal or the video signal, and the search speed is variable according to the state of the audio information or the video information. A recording / reproducing apparatus having a searching means. 2. A silent portion detecting means for detecting a silent portion of audio information read from the recording medium is provided, and a search speed is variable according to a length of the silent portion detected by the silent portion detecting means. The recording / reproducing apparatus according to claim 1, wherein 3. A motion detecting means for detecting the motion of the video information read from the recording medium is provided, and the search speed is variable according to the magnitude of the motion detected by the motion detecting means. The recording / reproducing apparatus according to claim 1. 4. When there is no voice information at the location where the search information is extracted when searching for the information, the search information is extracted by shifting from that location to the location where the voice information exists within a predetermined period. The recording / reproducing apparatus according to claim 1.