JPH0414680A - Rearrangement circuit - Google Patents

Abstract

PURPOSE:To avoid read from getting far ahead of write and to attain recording and reproduction with high quality by writing an input data to at least two memory means alternately and reading a storage data from a memory means with no write mode set thereto. CONSTITUTION:A signal recorded on a magnetic tape 50 is subject to electromagnetic conversion by a magnetic head 52, demodulated by a demodulation circuit 54, separated into a synchronization code and an ID code by a Sync ID separation circuit 56, subject to error correction by an error correction circuit 58 and the result is fed to a memory device 60. The memory 60 has a memory capacity at least twice that of an interleave sequence and an output of the circuit 58 is written in frame memories 60-1, 60-2 alternately for each frame. A deinterleave circuit 62 reads a storage memory with no write implemented thereto in the memories 60-1, 60-2 synchronously with a reproduction system frame signal 63.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a circuit that performs data rearrangement such as interleaving and dinterleaving.

[Prior Art] Is there a known recording/reproducing device that records digital signals on a magnetic tape using a helical scan method? For this purpose, a recording method in which interleaved recording is performed under predetermined rules is also known (for example, Patent Application Publication No. 306504 of 1988).

FIG. 3A shows a plan view of a rotating drum of such a digital recording/reproducing apparatus, and FIG. 3B shows a developed view of the rotating drum. 10 is a rotating tram, 12A12B, 14A, 14
B is a magnetic head for recording or reproducing, and 16 is a magnetic tape. The head 12A 714A has a positive azimuth, and the heads 12B and 14B have a negative azimuth. 14A and 14B are arranged 180 degrees apart in the circumferential direction of the rotary tram 10. For recording or reproduction, the pair of heads 12A, 12B and the pair of heads 14A, 14B are used alternately.

FIG. 4 shows an interleave recording pattern when digitally recording a video signal. Each track may originally be inclined with respect to the magnetic tape, but in FIG. 4 each track is shown standing up for ease of illustration and understanding. n−m within the individual blocks of each truck is
n indicates the field number, and m indicates the scanning line number within that field.

Here, the video signal of the real screen image (1056 effective scanning lines) as shown in Fig. 5 is handled, and 12
One frame of video data is recorded on a book track, and the frame sequence is interleaved. Therefore, within the time of field #0 (i.e. tracks #1-6)
) also includes the image data of field #1, and similarly, the image data within field #1 (i.e., tracks #7 to #12)
also includes the image data of field #0.

Such data rearrangement for interleaving and deinterleaving has been performed by controlling addresses in the frame memory.

FIG. 6 is a simplified state diagram of memory read/write addressing during recording, that is, for interleaving;
The figure is a simplified state diagram of memory read/write addressing for deinterleaving. However, FIG. 6 shows only the A channel (heads 12A, 14A).

In interleaving, as shown in FIG. 6, when writing to memory, the write address is changed by a fixed amount in units of scanning lines, and when reading from memory, the address is changed linearly as shown by the straight line 18. let This results in
As shown in FIG. 4, the data of each scanning line is distributed in each track.

Furthermore, in deinterleaving, as shown in FIG. 7, when writing to memory, the write address is changed by a fixed amount in units of reproduced data blocks. This results in
Each scan line is stored in memory in accordance with the order of addresses. Therefore, when reading from the memory, it is sufficient to change the address linearly as shown by a straight line 19.

[Problems to be Solved by the Invention] However, in interleaving and deinterleaving using such adren% control, an overtaking phenomenon occurs in which a data portion (or a data portion of the previous image) that has not yet been written is read out. This may cause defects in recorded images or deterioration in the quality of reproduced images.

Therefore, an object of the present invention is to provide a rearrangement circuit that solves these problems.

[Means for Solving the Problems] A sorting circuit according to the present invention is a circuit that sorts input data in an order according to a predetermined rule, and includes at least two memory means capable of accommodating a unit amount of data to be sorted,
The present invention is characterized in that input data is written alternately into the at least two memory means, and stored data is read from the memory means to which no writing is being performed.

[Operation] By the above means, there is no need to read an area that has not yet been written or an area where previous input data remains, so that no deterioration of signal quality occurs.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1A shows a block diagram of an embodiment in which the present invention is applied to interleave processing in a digital recording apparatus. 3
0 is an input terminal for an analog video signal, and the A/D converter 32 converts it into a digital signal and sends it to the memory device 34.
supply to. Memory device 34 has at least twice the memory capacity of the interleaved sequence (e.g., frame
two frame memories 34-1 in the case of sequences;
34-2).

According to the frame signal 37, the interleaving circuit 36
Image data stored in memory device 34 is interleaved. In this embodiment, in order to avoid overtaking memory reads and memory writes, when writing to one frame memory (e.g. 34-1) of memory device 34, writing to another frame memory (e.g. 34-1)
-2) The frame memory to be read from and written to is switched for each frame.

Address control elements for writing and reading are the same as in the conventional example. FIG. 2 shows a simplified state diagram of write/read addressing of memory device 34.

The image data read out from the memory device 34 is added with an error correction code by the error correction code addition circuit 38, and the 5y
5sync of the synchronization block by the nc-ID addition circuit 40
The data is coated with a coat and an ID coat, modulated by a modulation circuit 42, and recorded on a magnetic tape 46 by a magnetic head 44. Image data is recorded on the magnetic tape 46 in a pattern as shown in FIG.

FIG. 1B is a configuration block diagram of an embodiment in which the present invention is applied to a playback device. The signals recorded on the magnetic tape 50 in an interleaved manner as shown in FIG. The error is corrected by the error correction circuit 58 and the signal is supplied to the memory device 60 . Memory device 60, like memory device 34, has at least twice the memory capacity of the interleaved sequence (e.g. two frame memories 60- for a frame sequence).
1.6O-2), and the output of the error correction circuit 58 is alternately sent to the frame memory 60-1.60-2 for each frame.
will be written to. The deinterleave circuit 62 synchronizes with the reproduction frame signal 63 and outputs the frame memory 60-
1,602, the stored data is read from the frame memory to which only writing has been performed. Addressing for writing and reading frame memories 60-1 and 60-2 is the same as in the conventional example, and deinterlimbing is performed by this writing and reading. Since reading is performed from the frame memory for which writing has been completed, reading does not overtake writing.

The image data read from the memory device 60 is converted into an analog signal by a D/A converter 64 and outputted from an output terminal 66 as an analog video signal.

Although the case of normal playback has been described, it is of course applicable to high-speed playback that is faster than the normal playback speed, and can also be applied to devices using recording media other than magnetic tape. Furthermore,
It goes without saying that interleaving other than the interleaving sequence described here can also be applied.

[Effects of the Invention] As can be easily understood from the above explanation, according to the present invention, reading does not overtake writing in memory access for interleaving or deinterlimbing, and high quality signals can be obtained. Can record and play.

[Brief explanation of drawings]

FIG. 1A is a block diagram of the configuration of a recording device that is an embodiment of the present invention, FIG. 1B is a block diagram of the configuration of a playback device that is another embodiment of the invention, and FIG. 2 is a simplified addressing state of FIG. 1A. Figure 3A is a plan view of the head arrangement of the rotating drum, Figure 3B is a developed view of the head arrangement of the rotating drum, Figure 4 is a recording pattern diagram, Figure 5 is a screen image diagram, and Figure 6 is an interleave memory/memory diagram. Addressing simplified state diagram,
FIG. 7 is a simplified state diagram of memory addressing for deinterleaving.

Claims (1)

[Claims] A circuit for rearranging input data in an order according to a predetermined rule, comprising at least two memory means capable of accommodating a rearranged unit amount of data, and writing input data alternately into the at least two memory means. A sorting circuit characterized in that it reads stored data from a memory means that is not used.