JP3441795B2 - Playback 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 reproducing device, and more particularly to a device for reproducing a digital image signal.

[0002]

2. Description of the Related Art Conventionally, there has been known a VTR which records an image signal and an audio signal as analog signals on a magnetic tape.

In recent years, there has been considered a digital VTR which digitizes image and audio signals, compresses the amount of information and records them on a magnetic tape.

When dubbing a recorded digital signal in such a digital VTR, the data reproduced by the master VTR is output to the slave VTR in a compressed form, It is considered to record as it is.

[0005]

However, in dubbing in such a digital VTR,
Because it is a structure that outputs the compressed data from the dubbing-like output terminal, the user cannot monitor the image and sound during dubbing, and cannot confirm the dubbing start position and end position, It was very inconvenient.

In view of the above problems, it is an object of the present invention to provide a reproducing apparatus capable of monitoring images and sounds even when performing dubbing.

[0007]

SUMMARY OF THE INVENTION In order to solve the conventional problems and achieve the above object, the present invention provides a reproducing means for reproducing an image signal whose information amount is compressed and subcode information from a recording medium. An expanding means for expanding the information amount of the image signal reproduced by the reproducing means; an interface for outputting the image signal reproduced by the reproducing means to the recording device in the compressed information amount; and the expanding means. Monitor means for displaying an image corresponding to the image signal expanded by and the sub-code information reproduced by the reproducing means, and the reproducing means for displaying the image signal and the sub-code information at a speed higher than the normal reproduction speed. An image signal reproduced from the interface at a speed faster than the normal reproduction speed so that the recording device records the compressed image signal. Outputs were configured to include an operation portion for setting a high-speed dubbing mode for displaying the sub-code information without displaying the image corresponding to the image signal by the monitoring means.

[0008]

Since the present invention is configured as described above, the information can be monitored even while the information signal is being dubbed.

[0009]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a digital signal recording / reproducing apparatus as a first embodiment of the present invention.
The figure shows the configuration when dubbing is performed using two digital signal recording / reproducing devices.

First, the operation of the master device 1 during normal recording will be described.

In FIG. 1, the left and right stereo audio signals obtained from the stereo microphone 2 are converted into digital signals by the A / D converters 4 and 5, respectively, and various audio signals are removed by the audio signal processing circuits 7 and 8, respectively. Processing such as limiting the dynamic range is performed. Then, the audio data compression circuit 10 performs audio signal compression processing on these digital audio signals and outputs them to the data synthesis circuit 13 and the ID generation circuit 12.

Here, as the compression processing for the audio signal,
Adaptive conversion coding proposed by the MPEG (Motion Picture coding Expert Group) standard, band division coding, and vector coding with two-channel mixing using the correlation of left and right audio signals are conceivable. It is also possible to use a compression method.

The image signal taken by the video camera 3 is converted into a digital signal by the A / D converter 6, and the image signal processing circuit 9 performs a predetermined process necessary for recording. Then, the image data compression circuit 11 compresses the digital image signal to reduce the information amount to several tens to several tens.
After compressing to 1/0, the data is output to the data synthesizing circuit 13 and the ID generating circuit.

Here, as a compression method for the image signal,
A method of compression using DCT, quantization, variable length coding, etc. within one screen, and motion compensation predictive coding using correlation between temporally different screens are conceivable, but other compression methods are available. It is also possible to use.

The digital image signal and the audio signal thus compressed are combined by the data combining circuit 13 and output to the switch 36. During normal recording, the system controller (hereinafter referred to as syscon) 16 connects the switch 36 to the camera side. The image and audio signals output from the switch 36 are stored in the main memory 18. The main memory 18 is controlled by the memory controller 17 such as setting a memory address and writing / reading each data.

The syscon 16 outputs a control signal indicating memory writing and reading to the memory controller in response to an instruction from the operation unit 19 such as recording, reproduction and retrieval, and also indicates the operation status of the device and recording / reproduction time. Information including the time code is displayed on the display unit 20. The time code is also output to the address information generation circuit 15.

There are two main types of this time code. 1
One is the elapsed time from the beginning of the recording medium or the video program and the cumulative time taken by the camera. The other is
It is data indicating the date and the hour, minute, second when recording or photographing the camera. Due to the latter time code generation, the calendar
The clock generation circuit 14 is provided.

The address information generation circuit 15 receives data such as the storage status of data in the main memory 18 from the memory controller 17, and transfers the data to the ID signal generation circuit 12 as information indicating the data amount of each information.

An example of the contents of this data is shown in FIG.

The address information generation circuit 15 includes a system controller 1
The time code, the image quality, the mode information of the sound, etc. are generated based on the information from 6, and the data amount of the image and the sound data based on the information from the memory controller 17 and the head of each data block in the main memory An address value is generated and transferred to the ID signal generation circuit 12. The ID signal generation circuit 12 collects these data as one data block for each ID and outputs the data block to the data synthesis circuit 13.

Next, the structure of data stored in the main memory 18 will be described.

FIG. 2 is a diagram showing an example of data storage in the main memory 18 composed of a solid-state memory such as a semiconductor memory. FIG. 2A is a diagram showing how the above-mentioned ID data is generated, and shows how ID data is generated for each period T0.

2B and 2C are conceptual diagrams of the address space of the solid-state memory. As shown in FIG. 2C, each I
After the D signal, image and audio data having different data amounts are sequentially stored by the variable length coding every predetermined processing time. Therefore, although the ID data is generated at regular intervals, it is not equidistant in the memory as shown in the figure.
Therefore, in order to enable high-speed access at the time of search, an ID file is generated in which addresses indicating storage locations of data blocks are grouped together as shown in FIG. 2B. This ID file stores only the head address of the data block in an area set in advance according to the storage capacity of the main memory 18.

This ID data has a fixed length, and in the example shown in FIG. 2D, a total of eight types of information are included.

Although the contents of each information shown in FIG. 2D are as described above, the deleted flag can be reproduced again before the physical deletion when the stored data is deleted. It is for erasing state,
Controls the presence or absence of this flag at the time of reproduction and controls whether or not to reproduce. As a result, no data is output at the time of reproduction, although it is not actually erased from the memory.

Further, in FIG. 2 (d), the audio data is composed of initial or information (reset data) of each of the left and right channels and variable-length audio data subjected to compression processing.

The image data is composed of, for example, an initialization screen (image reset data) by intra-screen encoding and the like, and compressed data which is variable length coded by various compression methods.

For each ID data, one set of the image data and the audio data having the above-mentioned configuration constitutes a data block.

Through such data processing, the main memory 1
Although the AV data is stored in 8, it is also possible to add a main memory or adopt a replaceable memory form such as an IC card.

Next, the reproducing operation of the master side device 1 during dubbing will be described.

At the time of dubbing, the user connects the AV digital terminal 35 on the master side and the AV digital terminal 135 of the slave side device 100 with the connection cable 42, and the device 1
The operation unit 119 of 00 is operated to enter the recording standby state. Here, in the configuration shown in FIG. 1, the slave side device 100 is configured to start and stop recording in synchronization with the reproduction start and stop of the master side device 1, but a detailed description thereof is omitted here. To do.

With the above-described structure, when the reproducing operation is first instructed by the operation unit 19 of the apparatus 1, the syscon 16 displays on the display unit 20 that the reproducing operation is in progress, and the memory control circuit 17 records each recording operation. Instruct to play the data. In response to this instruction, the memory control circuit 17 controls the main memory 18 to read the stored image, voice and ID data. Then, these data are combined in a serial interface (hereinafter referred to as I
/ F) 34 and the data distribution circuit 21.

Of these data, the data output to the data distribution circuit 21 is distributed and processed as follows.

The image data is decompressed by the image data decompression circuit 24 in the opposite direction to the compression process at the time of recording to increase the amount of information to the original amount of information, which is equivalent to the input signal at the time of recording. It is output to the data selection circuit 26 as an image signal.
The data selection circuit 26 selectively outputs the reproduced image signal and the audio signal to the adder 27, the D / A converter 29, the image digital output terminal 32 and the audio digital output terminal 33 as described later.

Regarding the ID data, the search information reproducing circuit 22 detects the information as shown in FIG. 2D for each ID data, and the display information reproducing circuit 23 displays the display information to be monitored by the finder 30. And is output to the adder 27. The data selection circuit 27 outputs the image signal to the adder when both the reproduced image and the display information are monitored, and the adder 27 combines the display information signal and the reproduced image signal to perform D / A conversion. Output to the container 28. Further, when monitoring only the display information, the image signal is not output to the D / A converter 28. Therefore, only the display information signal is output from the adder 27. The image and the display information corresponding to the image signal and the display information signal output from the D / A converter 28 are displayed by the finder 30. Such control of the data selection circuit 26 is performed by a control signal (not shown) from the syscon 16.

The voice data decompression circuit 25 subjects the voice data to a decompression process that is the reverse of the compression process at the time of recording, and the data selection circuit 2 outputs a voice signal equivalent to the input voice signal at the time of recording.
6 is output. The data selection circuit 26 selectively outputs the reproduced audio signal to the D / A converter 29 and the audio digital output terminal 33. Then, the audio signal converted into the analog audio signal by the D / A converter 29 is a speaker 31.
Monitored by.

Here, the deviation due to the delay time or the like required for the reproduction processing of the image and audio data is corrected by the above-mentioned ID data.

On the other hand, the respective compressed data output to the I / F 34 is converted into a format suitable for serial output as shown in FIG. 3, and the slave side device is connected via the AV digital terminal 35 and the connection cable 42. AV digital terminal 1
To 35.

System controller 116 of slave device 100
At this time, the switch 136 is connected to the dubbing side and the memory control circuit 117 is controlled so that the dubbing input data output from the I / F 134 is stored in the main memory 118 as it is.

The operation of the other parts of the device 100 is the same as that of the device 1, but image and audio recording signals are input from the analog input terminals 139, 137 and 138, respectively.

FIG. 3 is a diagram showing a state of data output via the I / F 34 and the AV digital terminal 35 during dubbing. Here, of the ID data shown in FIG. 2D, data not related to the output during dubbing is converted into data for serial output and output.

As described above, according to this embodiment,
Even when dubbing the image and audio signals that are still compressed, the image and audio being dubbed can be monitored, and it becomes easy to confirm the start and end positions of dubbing.

Next, a second embodiment of the present invention will be described.

Although the digital recording / reproducing apparatus using the solid-state memory has been described in the above embodiment, it goes without saying that
It is also possible to use another medium as the recording medium. In this embodiment, a case where the present invention is applied to a digital VTR for recording / reproducing a digital signal on / from a magnetic tape will be described.

FIG. 4 is a block diagram showing the configuration of a digital VTR as the second embodiment of the present invention.

In FIG. 4, the process until the image and audio data is compressed, synthesized by the data synthesizing circuit 213 and outputted is the same as in the above-mentioned embodiment.

In the present embodiment, the ID generation circuit 212 is controlled by the system controller 216 which receives an instruction from the operation unit 219 to generate the above-mentioned time code and also a subcode which is information such as a title of an image to be recorded. The data is generated and output to the data synthesis circuit 213. The data synthesizing circuit 213 synthesizes the compressed image and audio data with the ID data and the sub-code data, and the switch 23
Output to 6. The switch 236 is controlled by the syscon 216 and is connected to the camera side during normal reproduction.
The switch 246 is also controlled by the syscon 216 and is connected to the R side during recording and to the P side during reproduction. Then, the data output from the data synthesizing circuit 226 is output to the head 47 via the switch 236 and the switch 246, and this head 47 causes the cassette 248.
It is recorded on the tape inside. In this embodiment, the head 47 is a rotary head provided on a drum (not shown).

The digital VTR is a conventional analog VTR.
Similarly, a drive unit 245 for moving the tape is provided, and the drive control circuit 244 controls the operating state of the drive unit 245 while communicating with the system controller 216. Also, in order to record the data accurately on the tape,
The servo system 243 controls the traveling system of the drive unit 245.

Next, the reproducing operation for dubbing will be described. AV digital terminal of other digital VTR and A
The connection with the V digital terminal 235 is the same as in the above-described embodiment.

When there is a reproduction instruction from the operation unit 219,
The system controller 216 displays the fact that the reproducing operation is in progress on the display unit 20, outputs a control signal to the drive control circuit 244, and causes the drive unit 245 to run the tape in the cassette 248.
At this time, the servo circuit 243 controls the drive unit 2 so that the head 47 can correctly reproduce the data recorded on the tape.
The traveling system of 44 is controlled. At this time, the switch 246 is connected to the P side, and the data reproduced by the head 47 is output to the I / F 234 and the data distribution circuit 221.

The subsequent processing is similar to that of the above-mentioned embodiment.

FIG. 5 shows the format of dubbing data output from the AV digital terminal 235 in this embodiment. In the format of this embodiment, 3 bytes of ID data are added to 77 bytes of image and audio data recorded on the tape and 80 bytes are output as one block. Further, the subcode data is output with the ID data added separately.

As described above, also in this embodiment, it is possible to monitor the image and the sound during the dubbing.

In the above-described embodiment, the reproduction speed during dubbing is the same as that during normal reproduction, so that the reproduced data can be processed as it is for monitoring.

Here, considering high-speed dubbing in which the output speed of the dubbing data from the I / F is increased by increasing the reproduction speed as compared with the normal reproduction, in this case,
There is no problem with data output as dubbing data, but when performing decompression processing to increase the amount of information corresponding to the original signal for the data reproduced at high speed,
It is conceivable that the speed of the expansion processing of the reproduction signal for monitoring cannot keep up with the output speed of the dubbing data.

As a third embodiment of the present invention, a digital VTR capable of monitoring data during dubbing even when high speed dubbing is performed will be described below.

FIG. 6 is a block diagram showing the structure of a digital VTR as a third embodiment of the present invention. The same components as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 6, when an instruction for high-speed dubbing (double speed in this embodiment) is given by the operation unit 219, the syscon 216 outputs a control signal to the drive control circuit 244 to normalize the tape. The data is reproduced at a speed twice as high as the normal speed by traveling at twice the speed and doubling the rotation speed of a drum (not shown).

The data reproduced at double speed is I / F23.
4 and the data reduction circuit 249. I / F23
4 converts the reproduction data into a format for dubbing and outputs it at a double speed as in the above embodiment.

Further, at this time, the syscon 216 controls the data reduction circuit 249 to reduce the data amount of the reproduction data to the extent that it can catch up with the dubbing speed, and the data distribution circuit 2
21 is output. As a method of reducing this data amount, 1
A method of thinning out pixels on the screen, a method of outputting only the DC component in the image data, a so-called frame dropping method of outputting every other screen, and the like can be considered. In the present embodiment, the dubbing speed (playback speed) is doubled, so the data amount reduction circuit 2
At 49, the data amount of the reproduced data is reduced to 1/2.

With respect to the monitor during dubbing, unlike viewing a reproduced image in normal reproduction, it is sufficient to confirm what kind of image has been dubbed. Therefore, the data amount is reduced in this way, so to speak, the image quality is inferior. Even images can be used.

The following processing for the reproduction data is the same as in the above-mentioned embodiment.

According to the present embodiment, by reducing the data amount in this way, it is possible to monitor the dubbing data without delaying the processing for the reproduced data even if the dubbing speed is doubled. .

In this embodiment, the case where dubbing is performed at double speed has been described. However, when performing high-speed dubbing at a speed other than this, the data amount reduction circuit 249 reduces the dubbing speed (reproduction speed). By changing the amount of data to be reproduced, that is, by controlling the rate of increase in the amount of information in the decompression process during reproduction, the image quality becomes rough but can be monitored.

Further, when high-speed dubbing is performed, the amount of data to be subjected to decompression processing may be extremely small and the monitor image may be deteriorated to an unnoticeable level. In this case, the data distribution circuit 221 is used. However, only the subcode data described above may be output.

In this case, the title and time code based on the subcode data are displayed on the finder 230, but these data are sufficient if only the dubbing start position and the end position are confirmed.

[0068]

As described above, according to the present invention, even when the reproduced image signal is output to the recording device in a state where the information amount is expanded and dubbed, the image signal being dubbed It becomes possible to monitor.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a recording / reproducing apparatus as an embodiment of the present invention.

FIG. 2 is a diagram showing a state of data in the apparatus of FIG.

3 is a diagram showing a format of dubbing data in the apparatus of FIG.

FIG. 4 is a digital VTR as a second embodiment of the present invention.
3 is a block diagram showing the configuration of FIG.

5 is a diagram showing a format of dubbing data in the apparatus of FIG.

FIG. 6 is a digital VTR as a third embodiment of the present invention.
3 is a block diagram showing the configuration of FIG.

[Explanation of symbols]

16 system controller 18 main memory 30 finder 31 speakers 34 serial interface 248 cassettes

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Claims (2)

(57) [Claims] 1. A reproducing means for reproducing an image signal whose information amount is compressed and sub-code information from a recording medium, an expanding means for expanding the information amount of the image signal reproduced by the reproducing means, and the reproducing means. An interface for outputting the image signal reproduced by the recording apparatus to the recording apparatus in a state where the amount of information is compressed, and an image corresponding to the image signal expanded by the expanding unit and the subcode information reproduced by the reproducing unit are displayed. Monitor means for reproducing the image signal and the sub-code information at a speed higher than a normal reproduction speed by the reproduction means, and the normal reproduction speed from the interface so that the recording device records the compressed image signal. The reproduced image signal is output at a higher speed, and the monitor unit displays an image corresponding to the image signal. Reproducing apparatus and an operation portion for setting a high-speed dubbing mode for displaying the sub-code information. 2. A reproducing means for reproducing an image signal whose information amount is compressed from a recording medium, an expanding means for expanding the information amount of the image signal reproduced by the reproducing means, and an image reproduced by the reproducing means. An interface for outputting a signal to a recording device in a state where the amount of information is compressed, a monitor unit for displaying an image corresponding to the image signal expanded by the expanding unit and time code information of the image signal, and the reproducing unit. Reproduces the image signal at a speed higher than the normal reproduction speed, and outputs the image signal reproduced at a speed higher than the normal reproduction speed from the interface so that the recording device records the compressed image signal. At the same time, a high-speed dubbing mode for displaying the time code information without displaying the image corresponding to the image signal by the monitor means is set. Reproducing apparatus including an operation unit for constant for.