JP2000092446A - Recording and reproducing device for television program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide at a low price a recording and reproducing device for television programs which uses a hard disk. SOLUTION: A recording system is provided with a data compressing circuit 3V, which compress the data of a video signal, and a reproduction system is provided with a data expanding circuit 6V of the data of a playback signal. The data compressing circuit 3V outputs its output signal, so that a main signal SMN representing rough information and a reinforcing signal SSB providing information close to the original information by reinforcing the main signal SMN are divided and outputted. The data expanding circuit 6V expands the data of the main signal SMN and reinforcing signal SSB into a video, signal having the information close to the original information and output, when supplied with the both as the playback signal and expands the data of the main signal SMN into a video signal having rough information and outputs, when supplied with only the main signal SMN as the playback signal. The residual quantity of the hard disk 5 become less than a specified quantity, the reinforcing signal SSB recorded on the hard disk 5 is erased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording and reproducing television programs.

[0002]

2. Description of the Related Art A video tape is generally used for recording a video signal. In recent years, a method of digitizing a video signal and compressing and recording the data on a hard disk has been put to practical use.

[0003]

By the way, as a general use of a so-called VCR, there is a method of taking out a television program and reproducing it at a later time.

However, a hard disk cannot be easily taken out of a recording / reproducing apparatus like a tape cassette and has a finite recording capacity, so that a recording time becomes a problem in a recording apparatus using a hard disk. For example, even if the capacity of the hard disk is 10 GB, the video signal and the audio signal are transmitted at a rate of 4M / sec.
When recording at a rate of 8 Mbits, the recording time is several hours.

Therefore, in a recording / reproducing apparatus using a hard disk, as in the case of a VCR, even if a TV program is taken out and then reproduced at a time, only a few one-hour programs can be recorded. is there.

On the other hand, if a program is a news or a drama even if the program is taken out, many days have passed since the recording, or when the next episode was watched, The need to play the program is reduced. Alternatively, when the next episode is watched in a drama, the previous episode often requires only an outline. The same can be said of the old news. In the case of the outline, there is not much problem even if the image quality is low enough to grasp the broadcast contents.

Therefore, when a program is recorded on a hard disk, high-quality recording is performed when recording is performed for the first time, and when the remaining capacity of the hard disk is reduced, the first recording is replaced with a low-quality recording. It is conceivable to reduce the used amount of the hard disk and increase the remaining amount.

However, in this case, once the recorded signal is reproduced, the data is compressed, and the data-compressed signal is recorded again. Therefore, a device which can execute reproduction and recording at the same time, or This requires two units, a recording device and a recording device, which increases the burden on the user.

The present invention is intended to solve the above problems.

[0010]

Therefore, according to the present invention, there is provided a data compression circuit for compressing a video signal of a television program, and a recording for recording an output signal of the data compression circuit on a recording medium capable of random access. Means, a reproduction means for reproducing a signal recorded on the recording medium from the recording medium, and a data decompression circuit for decompressing and outputting a reproduction signal reproduced by the reproduction means, wherein the data compression circuit comprises: As the output signal, a main signal that reproduces rough information and a reinforcement signal that reinforces the main signal and provides information close to the original information are divided and output, and the data decompression circuit includes: When the main signal and the reinforcement signal are supplied as the reproduction signal, the data is expanded and output to a video signal having information close to the original information, Serial when only the main signal is supplied as a reproduction signal is adapted to output the data decompression into a video signal having the rough information, when the remaining amount of the recording medium is smaller than the predetermined amount,
According to another aspect of the present invention, there is provided a recording / reproducing apparatus for a television program configured to delete the reinforcing signal recorded on the recording medium. Therefore, even if the video signal on the recording medium is not reproduced and re-recorded, the remaining amount of the recording medium increases, and recording is performed this time.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a circuit 1 is a receiving circuit having from a tuner circuit to a video detecting circuit and an audio detecting circuit.
A color video signal and an audio signal of the system are output. The circuits 2V and 2S include an A / D converter circuit for A / D converting the color video signal and the audio signal, and a circuit 3
V and 3S are data compression circuits for compressing digital video signals and digital audio signals.

In this case, the compression circuit 3V compresses the video signal by a compression process such as an MPEG process or a wavelet transform using a technique such as DCT (discrete cosine transform). The data-compressed video signal is output after being divided into a main signal SMN that reproduces rough information and a reinforcement signal SSB that reinforces the main signal SMN and provides information close to the original information. . This main signal S
The combination of the MN and the reinforcement signal SSB is generally called scalability. For example, in the case of compression using DCT, the quantization table of DCT coding mainly focuses on low frequency components. Information is the main signal SMN
And the remaining high frequency component is the reinforcement signal SSB.

Further, the circuit 4 is a hard disk controller, and reference numeral 5 denotes a hard disk (hard disk drive). In this case, the controller 4 has a circuit that controls writing and reading of data to and from the hard disk 5.
Is a recording medium for a color video signal and an audio signal. Then, a management area is prepared on the hard disk 5 as in the case of using a general computer,
In the management area, data such as a recording state of a signal, that is, information indicating a cluster used for recording, a recording start time, and a reproduction flag indicating whether or not reproduction has been performed at least once after recording is stored.

The circuits 6V and 6S are data decompression circuits for decompressing data compressed signals to original signals. The decompression circuit 6V is adapted to receive the main signal SMN and the supplementary signal SSB. A high-quality video signal having information close to the original information is output, and when only the main signal SMN is supplied, a low-quality video signal having general information is output. The circuits 7V and 7S are D / A converter circuits.

The circuit 11 is a system control microcomputer for controlling the operation of the entire apparatus. The microcomputer 11 has a memory 1 for storing data such as the start time and end time of programmed recording.
2, a timer 13 for outputting current time data, various operation keys 14, and a display element, for example, an LED 15 are connected.

In such a configuration, when the recording operation is performed by the operation keys 14, the operation of the hard disk controller 4 is controlled by the microcomputer 11,
The program received by the receiving circuit 1 is recorded on the hard disk 5 as follows.

That is, normally, the color video signal and the audio signal from the receiving circuit 1 are
A / D converted into digital signals by V and 2S, and then supplied to data compression circuits 3V and 3S. From the compression circuit 3V, a main signal SMN obtained by compressing a digital video signal and a reinforcement signal SSB are taken out. From the compression circuit 3S, a signal SAU obtained by data compression of the digital audio signal is taken out.

The signals SMN, SSB and SAU are:
The data is supplied to the hard disk controller 4 and recorded (written) on the hard disk 5. However, in this case, the signal SMN and the signal SSB are independently recorded in separate clusters. The signal SAU may be combined with the signal SMN and recorded in the same cluster, or may be recorded in an independent cluster. The information indicating the cluster used for this recording and the data of the recording start time are
Recorded in the memory 12. Thus, the program received by the receiving circuit 1 is recorded on the hard disk 5. In addition,
This recording is performed by the signals SMN, SSB, and SAU, so that high-quality recording is achieved.

When a stop operation is performed by the operation key 14, the recording of the signals SMN, SSB and SAU on the hard disk 5 is terminated by the hard disk controller 4. At this time, the information indicating the cluster used for recording and the data of the recording start time are read from the memory 12 and supplied to the hard disk controller 4 to be recorded in the management area of the hard disk 5. Also,
At this time, the recording end time is also recorded, and data indicating the broadcast channel of the recorded program is also recorded. Further, the corresponding reproduction flag is reset.

In the case of scheduled recording, the microcomputer 11 checks the preset recording time set in the memory 13 against the current time indicated by the timer 14, and the current time indicated by the timer 14 determines the current recording time. At the time, the recording starts as described above, and at the end time, the recording ends.

When a reproduction operation is performed using the operation keys 14, data indicating a recording time is read from the management area of the hard disk 5 and supplied to the microcomputer 11, and a list of the recording times is displayed on the LED 15. .

When the desired recording time of the program is selected by operating the key 14, the information of the corresponding cluster is read out of the information indicating the cluster used for recording in the management area of the hard disk 5, and Thereafter, the signals SMN, SSB and SAU are sequentially read from the hard disk 5 by the controller 4 according to this information. The read signals SMN, SSB, and SAU are supplied to the data expansion circuits 6V and 6S through the controller 4, where they are expanded to the original digital video signals and digital audio signals. / A is supplied to the converter circuits 7V and 7S and converted into an analog signal by D /
After the A conversion, it is taken out to the output terminals 8V and 8S.

Thus, the program recorded on the hard disk 5 is reproduced. At this time, the reproduction flag of the reproduced program is set.

On the other hand, when recording is repeated, the remaining amount of the hard disk 5 becomes small, and finally, new recording cannot be performed.

Then, in this case, prior to recording,
By referring to the management area of the hard disk 5, 1
It is checked whether or not a program of the same broadcast channel is being recorded in the same time zone as this recording (program) one day before or one week before, that is, the previous program corresponding to the current program is recorded. It is checked whether the recording has been performed, and if the recording has been performed, the reinforcement signal SSB of the recording is deleted from the hard disk 5. When the recording is not performed, the recording in which the reproduction flag is set, that is, the reinforcing signal SSB of the program that has been reproduced once is deleted from the hard disk 5. These erasures are executed by rewriting the information in the management area of the hard disk 5, and are therefore executed instantaneously.

Therefore, since the remaining capacity of the hard disk 5 becomes large, the current recording is executed as described above.
This recording is performed with high image quality by recording the signals SMN, SSB and SAU.

When such recording is performed, the video signal of the previous program is reproduced only by the SMN. However, since the signal SMN is a signal of information for reproducing rough information, the signal of the previous program is reproduced. Will be reproduced in low image quality, but its contents can be known. When the previous program and the current program are played,
All the signals SMN and SAU of the previous program are deleted,
The reproduction flag of the current program is set as described above.

Thus, according to the above-described apparatus, at the time of recording a program, a video signal is converted to a main signal S for reproducing rough information.
MN and a reinforcement signal SSB which reinforces the signal SMN and provides information close to the original information are recorded separately. When the remaining capacity of the hard disk 5 is insufficient, the reinforcement signal SSB is deleted and the required capacity is reduced. To ensure that. Therefore,
As in the case of reproducing the once recorded video signal and compressing the data, and recording the compressed video signal again, there is no need for a recording device and a reproducing device, thereby reducing the burden on the user. Can be smaller.

Further, since the erasing of the reinforcement signal SSB can be executed only by rewriting the management area of the hard disk 5,
This can be done instantaneously, so that the previous program can be kept until it becomes necessary to increase the remaining capacity of the hard disk 5 when performing a new recording.

Furthermore, since the recording capacity of the previous program can be automatically compressed or deleted, the user does not need to perform those operations, and the user can feel secure that recording can be performed at any time.

In the above description, the program is recorded and reproduced on the hard disk 5. However, when a recording medium for recording and reproducing (writing / reading) by random access, for example, a CD-RW or DVD-RAM is used. The present invention can also be applied to the present invention. Also, the audio signal SAU can be divided into a main signal and a reinforcement signal and similarly recorded, reproduced, and erased.

[0032]

According to the present invention, the problem that when several programs are recorded on a medium having a finite and small recording capacity such as a hard disk, the remaining amount becomes short immediately and new recording cannot be performed is drastically eliminated. Can be settled. In addition, this makes it possible to improve the merchantability of a recording / reproducing apparatus that can always perform recording.

[Brief description of the drawings]

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

[Explanation of symbols]

1 = receiver circuit, 2V and 2S = A / D converter circuit, 3V and 3S = data compression circuit, 4 = hard disk controller, 5 = hard disk (hard disk drive), 6V and 6S = data decompression circuit, 7V
And 7S = D / A converter circuit, 8V and 8S =
Output terminal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/081

Claims (3)

[Claims] 1. A data compression circuit for compressing a video signal of a television program, a recording means for recording an output signal of the data compression circuit on a recording medium capable of random access, and a recording medium recorded on the recording medium from the recording medium. And a data decompression circuit for decompressing and outputting the reproduction signal reproduced by the reproduction means. The data compression circuit reproduces rough information as the output signal. The main signal and the reinforcement signal that reinforces the main signal and provides information close to the original information are divided and output, and the data decompression circuit includes the main signal and the reinforcement signal as the reproduction signal. When supplied, the video signal having information close to the original information is decompressed and output, and only the main signal is supplied as the reproduction signal. Sometimes, the video signal having the rough information is expanded and outputted, and when the remaining amount of the recording medium becomes smaller than a predetermined amount, the reinforcement signal recorded on the recording medium is erased. A recording / reproducing apparatus for a television program. 2. The recording / reproducing apparatus for a television program according to claim 1, wherein when recording a current broadcast of said television program, said remaining amount of said recording medium is smaller than a predetermined value. A recording / reproducing apparatus for a television program, wherein the augmentation signal when a previous broadcast of the television program is recorded is deleted from the recording medium. 3. The recording / reproducing apparatus for a television program according to claim 2, wherein the erasing of the reinforcement signal is executed by rewriting a management area on the recording medium. Playback device.