JP2985177B2 - Digital information processing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a digital information processing apparatus for transmitting digital information.

[Prior Art] A device that includes a video signal recording / reproducing system and transmits / receives a video signal conventionally includes a video processing circuit system and an audio processing circuit system. Third
Shown in the figure. In the audio processing circuit system shown in FIG. 3, an analog audio signal is digitized by an A / D converter 10 and an error correction code adding circuit 12 adds an error correction code for correcting an error during recording and reproduction. Next, the data is modulated by the modulation circuit 14 and recorded on a recording medium 18 such as a video tape by a magnetic head 16 (a rotating magnetic head in the case of a VTR).
Magnetic head 20 (may also serve as magnetic head 16)
Reproduces the magnetic signal of the recording medium 18, and the demodulation circuit 22 demodulates the signal. The error correction circuit 24 uses the error correction code added by the error correction code addition circuit 12 to correct errors due to recording and reproduction.

When transmitting this reproduced signal, an error correction code adding circuit
26 adds an error correction code for correcting a transmission error to the output of the error correction circuit 24, and the modulation circuit 28 modulates for transmission and sends out to the transmission line 30. The demodulation circuit 32 is connected to the transmission path 30
Receive the data transmitted by the demodulator and demodulate it,
Corrects the transmission error by the error correction code added by the error correction code addition circuit 26. The D / A converter 36 converts the digital signal output from the error correction circuit 34 into an analog signal.

In the case of a video signal, there is band compression processing before recording processing on the recording medium, and there is band expansion processing corresponding to the band compression processing after reproduction from the recording medium or after reception processing from the transmission path. 2 is basically the same as that of FIG. 2 except that interpolation processing for missing data and the like is performed.

[Problems to be Solved by the Invention] As shown in the conventional example, in a transmission device having a recording / reproducing system, an error correction code adding circuit 12 and an error correcting circuit 24 for correcting an error accompanying recording / reproducing are provided. An error correction code adding circuit 26 and an error correction circuit 34 for correcting a transmission error are provided. Such a two-stage error correction process causes an increase in the circuit scale of the transmission device and an increase in cost.

Therefore, an object of the present invention is to provide a digital information processing apparatus that solves such a problem.

[Means for Solving the Problems] A digital information processing apparatus according to the present invention comprises a compressed digital image information to which a first error correction check code for error correction is added, and a second error information for error correction. A compressed digital image to which the first error correction check code is added from a recording medium on which a second digital information having a smaller amount of information than the compressed digital image information to which a correction check code is added is recorded. Reproducing means for reproducing information and the second digital information to which the second error correction check code is added, and an error of the compressed digital image information reproduced by the reproducing means, And a third error correction check code for correcting errors in the compressed digital image information corrected by the error correction means. Additional means for additionally adding, and transmission means for externally transmitting the compressed digital image information to which the third error correction check code is added and the second digital information to which the second error correction check code is added. It is characterized by having.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention for recording / reproducing and transmitting an information signal. In FIG. 1, reference numeral 40 denotes an A / D converter, and reference numeral 42 denotes a code having a higher error correction capability than an error correction code used for correcting a transmission error, for example, DEC code in two vertical directions and SEC / DED in one horizontal correction. (1 correction
/ 2 detection) error correction code addition circuit that adds a code, 44 is a modulation circuit for recording on a recording medium, 46 is a magnetic head for recording, 48 is a recording medium such as a video tape or magnetic disk, and 50 is a reproduction Magnetic head, 52 is a demodulation circuit corresponding to the modulation circuit 44, 54 is a modulation circuit for transmission, 56 is a transmission line, 58 is a demodulation circuit corresponding to the modulation circuit 54, and 60 is added by the error correction code addition circuit 42. An error correction circuit 62 performs error correction using the error correction code, and 62 is a D / A converter.

The operation of FIG. 1 will be described. The A / D converter 40 digitizes the analog audio signal, and the error correction code adding circuit 42
An error correction code having an error correction capability capable of covering a transmission error in the transmission path 56 is added. The data is recorded on the recording medium 48 by the modulation circuit 44 and the magnetic head 46, and the reproduction output of the magnetic head 50 is demodulated by the demodulation circuit 52. The output of the demodulation circuit 52 corresponds to the output of the error correction code adding circuit 42 as long as there is no error associated with recording and reproduction.

The modulation circuit 54 modulates the output to the demodulation circuit 52 and sends it out to the transmission path 56, and the demodulation circuit 58 receives and demodulates the transmission data. The error correction circuit 60 corrects the data using the error correction code added by the error correction code addition circuit 42, and the D / A converter 62 converts the data into an analog signal.

At the input stage to the error correction circuit 60, it is estimated that the error rate is higher than in the conventional configuration.
By adopting the 42 error correction codes having high redundancy and high error correction capability, the correction can be performed sufficiently.

Next, an embodiment in which the present invention is applied to a video / audio simultaneous transmission system will be described with reference to FIG. In the figure, the same components as those in FIGS. 1 and 3 are denoted by the same reference numerals, and the detailed description is omitted.

In the figure, V _in is an input video signal, and A _in is an input audio signal.
As described above, the video signal digitized by the A / D converter 10 is subjected to band compression processing such as sub-sampling for reducing the number of pixels and encoding for reducing the number of bits of each pixel in the band compression circuit 11. After that, it is supplied to the error correction code adding circuit 12.

An error correction code for recording and reproduction is added to the video signal by the error correction code addition circuit 12, and an error correction code for recording and reproduction and transmission is added to the audio signal by the error correction code addition circuit 42. The time-division multiplexing circuit 43 time-division-multiplexes the video signal and the audio signal that have passed through the error correction code addition circuits 12 and 42,
The data is recorded on a recording medium 48 via 44.

The signal reproduced from the recording medium 48 is demodulated by a demodulation circuit 52, and then separated into a video signal and an audio signal by a data separation circuit 53. Addition of a correction code is performed in circuits 24 and 26. After being time-division-multiplexed again by the time-division multiplexing circuit 55, it is transmitted to the transmission line 56 via the modulation circuit 54.

The signal transmitted via the transmission path 56 is demodulated by a demodulation circuit 58 and then separated again into a video signal and an audio signal by a data separation circuit 59. The video signal is subjected to error correction during transmission by an error correction circuit 34. The audio signal is corrected by the error correction circuit 60 during recording / reproduction and transmission.

The video signal that has been subjected to error correction by the error correction circuit 60 is returned to the original number of bits by the band expansion circuit 35, and the number of bits reduced by encoding is reduced by subsampling pixels and dropouts. Interpolation for missing pixels is performed. V _out and A _out indicate an output video signal and an output audio signal, respectively.

In the configuration as described above, the circuit configuration of the audio signal processing system can be greatly simplified. Here, the redundancy of the audio signal increases, and the amount of transmission data increases accordingly. However, since the bandwidth of the audio signal is sufficiently narrower than that of the video signal, the increase does not cause much problem. Therefore, it is possible to simplify the circuit configuration without deteriorating the image quality and the sound at all.

Although the number of error correction circuits and error correction code adding circuits can be reduced for a video signal as in the case of an audio signal, the number of redundant data to be transmitted is considerably increased. Therefore, when it is desired to simplify the circuit configuration of the video signal processing system, it is possible to respond by increasing the band compression ratio of the band compression circuit 11.

In the above embodiment, the recording / reproducing system is provided on the information transmitting side. Of course, when the recording / reproducing system is provided on the receiving side, and when the recording / reproducing system is provided on both the transmitting side and the receiving side. Needless to say, this can also be applied.

[Effects of the Invention] As can be easily understood from the above description, according to the present invention, it is possible to simplify the circuit and reduce cost and image degradation.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram of an embodiment in which the present invention is applied to a video / audio transmission system, and FIG. 3 is a block diagram of a conventional example. 40: A / D converter, 42: error correction code addition circuit, 44: modulation circuit, 46: recording magnetic head, 48: recording medium, 50: reproduction magnetic head, 52: demodulation circuit, 54: modulation circuit, 56: Transmission line, 58:
Demodulation circuit, 60: error correction circuit, 62: D / A converter

Claims (1)

(57) [Claims] 1. A compressed digital image information to which a first error correction check code for error correction is added and a compressed digital image information to which a second error correction check code for error correction is added. The compressed digital image information to which the first error correction check code is added and the second error correction check code are added from a recording medium on which the second digital information having a smaller amount of information is recorded. The second
Reproducing means for reproducing the digital information of the present invention, error correcting means for correcting an error of the compressed digital image information reproduced by the reproducing means using the first error correction check code, and correction processing by the error correcting means. Adding means for newly adding a third error correction check code for error correction to the compressed digital image information obtained, and the compressed digital image information added with the third error correction check code and the second error. Transmitting means for externally transmitting the second digital information to which the correction check code has been added, and a digital information processing apparatus.