JPH0541035A - Recording and reproducing system of animation picture data - Google Patents

Abstract

PURPOSE:To reproduce compressed animation picture data, which are recorded in a helical scan digital tape recorder, with an approximately same image quality of an ordinary reproduction. CONSTITUTION:Compressed animation picture data are rearranged so that the core frame data are recorded in the specific location on the tape by an ordinary reproduction codec 1, error correction parities are added and interleave takes place by error correction codecs 2 and 3 and the data are dispersedly recorded on the tape as the main data of DATA/DAT. During a nine times speed reproduction, main data, which correspond to one core frame arrangement, are reproduced from the tape, error corrections and data interleave take place by the C1 and C2 error correction codec 3, one core frame data are extracted by a high speed reproduction decoder 4 and the data are outputted via a selector 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving picture data recording / reproducing system for high speed reproduction in a moving picture recording / reproducing apparatus using a helical scan digital tape recorder.

[0002]

2. Description of the Related Art Digital audio tape (DAT)
Originally, it was originally developed for audio, but in recent years, its application as an external storage device of a computer is spreading, and it has been standardized as a DATA / DAT format.

In a moving image data recording / reproducing apparatus using a helical scan digital tape recorder such as DATA / DAT, during high-speed reproduction, the bit rate of the reproduction signal becomes the same as that of normal reproduction in accordance with the tape speed. As described above, the rotation speed of the cylinder is controlled to perform tracking by ATF (Automatic Track Finding). Here, considering that n-fold speed reproduction is performed, when n is an odd number, it is possible to reproduce data of tracks of both positive and negative azimuth angles at n track intervals, and n
Is even, it is possible to reproduce the data of the track of either positive or negative azimuth angle at 2n track intervals.

[0004]

Generally, when the compressed moving image data is decoded, if the data is missing, the image quality is greatly affected and the decoding process becomes complicated.
Therefore, when recording moving image data in DATA / DAT, it is necessary to consider the high speed reproduction so that the high speed reproduction is possible.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a new recording / reproducing system for realizing high-speed reproduction with substantially the same image quality as during normal reproduction. .

[0006]

In order to achieve the above object, in the moving image data recording method according to the present invention, high speed is achieved when recording compressed moving image data in a helical scan digital tape recorder. It is characterized in that core frame data obtained by compressing only data in one moving image frame is dispersed and recorded on a tape in accordance with a frame interval to be reproduced at the time of reproduction.

Further, in the moving image data reproducing method according to the present invention, when the compressed moving image data is recorded in the helical scan digital tape recorder, one moving image frame It is characterized in that core frame data obtained by compressing only the above data is dispersed and data recorded on a tape is read at intervals of several frames, and the core frame data is reconstructed and reproduced.

[0008]

In the moving image data recording / reproducing method according to the present invention, the data of the core frame is rearranged so that the data is arranged at a specific position on the tape, and the data is recorded.
Since it is possible to reproduce the core frame during high-speed reproduction, high-speed reproduction can be realized with almost the same image quality as during normal reproduction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the embodiments of the present invention in detail with reference to the drawings, the principle of the present invention will be described first in order to help understanding of the present invention.

FIG. 2A is a diagram showing an outline of a DATA / DAT group format 1 as an example of a helical scan digital tape recorder. In the figure, a frame is composed of a positive azimuth track and a negative azimuth track following it.

FIG. 2B is a diagram showing an outline of compressed moving image data. In the figure, the core frame is data of a moving picture frame in which only information in one moving picture frame is compressed, and the inter frame is data of a moving picture frame compressed using information of two or more moving picture frames.

In order to support high-speed reproduction of n times, the core frame data is allocated to a continuous area of positive azimuth tracks every n frames by allocating the number of blocks according to the data amount of the core frame and distributing as follows. To record. However, F represents the frame number in the group. Core frame 0 → F ₀ , F _n , F _2n , ... Core frame 1 → F ₁ , F _{n + 1} , F _{2n + 1} , ... Core frame 2 → F ₂ , F _{n + 2} , F _{2n + 2} , ... :: Core frame n-1 → F _(n-1) , _{Fn + (n-1)} , _{F2n + (n-1)} , ... When the data recorded as above is reproduced at n times speed,
One core frame data of the core frames 0 to (n-1) can be reproduced. In addition, when n / 2, n / 3, ... Are integers, when reproduced at n / 2, n / 3, ... Double speed, 2, 3, ... Of core frames 0 to (n-1)
Each core frame data can be reproduced. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a structure for carrying out this recording / reproducing system. In the figure, 1 is a normal reproduction for mutually converting a compressed moving image data and a data arrangement format on a tape. Codec: Corder / Decorde
r). Reference numeral 2 is a codec for C ₃ error correction, and 3 is a codec for C ₁ and C ₂ error correction. Reference numeral 4 is a decoder for high speed reproduction, and 5 is a selector for switching data during normal reproduction / high speed reproduction. Next, the operation in such a configuration will be described.

When compressed moving image data as shown in FIG. 3A is input from point A at the time of recording, the core frame data is recorded at a specific position on the tape by the normal reproduction codec 1. The data is rearranged as described above, and error correction parity is added and interleaved by the C ₃ error correction codec 2 and the C ₁ and C ₂ error correction codec 3, respectively.
It is output from point C as main data of / DAT. Here, the specific position is the head portion of the frame shown in FIG. 3B, and the number of blocks is determined in advance according to the data amount of the core frame. However, since the shaded portion 6 in FIG. 3B includes C ₃ parity, core frame data is not assigned.

On the other hand, during normal reproduction, the reproduced main data is input from the point D, error-corrected and deinterleaved by the C ₁ and C ₂ error correction codec 3 and the C ₃ error correction codec 2, The compressed moving image data is rearranged by the normal reproduction codec 1 in the same order as shown in FIG. 3A at the time of recording, and is output to the point B through the selector 5.

During 9 × speed reproduction, main data of a frame corresponding to the arrangement of one core frame among core frames 0 to 8 in FIG. 3B is reproduced and input from point D. This input data is error-corrected and deinterleaved by the C ₁ and C ₂ error-correcting codec 3. The deinterleaved data is input to the high-speed reproduction decoder 4, the data of one core frame is extracted, and is output to the point B via the selector 5.

Further, at the time of 3 × speed reproduction, FIG.
Out of core frames 0 to 8 of core frames 0, 3,
6, core frame 1, 4, 7, or core frame 2,
The main data of the frame corresponding to the arrangement of the three core frames 5 or 8 is reproduced and input from the point D. This input data is error-corrected and deinterleaved by the C ₁ and C ₂ error-correcting codec 3. The deinterleaved data is input to the high-speed reproduction decoder 4, the data of three core frames is extracted, and is output to the point B via the selector 5.

As described above, in this embodiment, DATA /
81 moving image frames of moving image data compressed for every two groups of DAT group format 1 are recorded.
By recording each of the nine core frames dispersed in every ninth frame and recording, it is possible to support high-speed reproduction at 9 × speed or 3 × speed, and one or three core frames can be reproduced for every two groups.

The above embodiment is an example in which the format of the compressed moving image data has a fixed core frame for every 9 moving image frames and all core frames are used for high-speed reproduction. It is not necessary to record the frame data at a specific position for high-speed playback, and only some of the core frames or some core frames may be overlapped and recorded at the specific position for high-speed playback. The speed is not limited to 3 times or 9 times, and may be any speed including reverse rotation. Also, group format 0
The system of the present invention can also be applied to (Group Format 0) and those having a high transfer rate such as DATA / DAT double speed support. The above description has been given by taking the example of DATA / DAT, but the method of the present invention is also effective for general digital tape recorders of the helical scan method.

[0020]

As described above in detail, according to the present invention, the core frame data is arranged at a specific position on the tape when the compressed moving image data is recorded on the helical scan digital tape recorder. By rearranging the data, it becomes possible to reproduce the core frame during high-speed reproduction, and high-speed reproduction with substantially the same image quality as during normal reproduction can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration for implementing a moving image data recording / reproducing system of an embodiment.

FIG. 2A is a schematic diagram of DATA / DAT group format 1, and FIG. 2B is a schematic diagram of compressed moving image data.

FIG. 3A is a diagram showing input compressed moving image data, and FIG. 3B is a table for explaining a specific position where core frame data should be recorded.

[Description of Codes] 1 ... Normal reproduction codec, 2 ... C ₃ error correction codec, 3 ... C ₁ and C ₂ error correction codec, 4
... High-speed playback decoder, 5 ... Selector.

Claims (2)

[Claims] 1. When recording compressed moving image data on a helical scan digital tape recorder, core frame data obtained by compressing only data within one moving image frame is dispersed in accordance with a frame interval reproduced at high speed reproduction. A method of recording motion image data, which is characterized in that it is recorded on a tape. 2. When recording compressed moving image data on a helical scan digital tape recorder, core frame data obtained by compressing only data within one moving image frame is dispersed according to a frame interval reproduced at high speed reproduction. Then, the high-speed reproduction system of moving image data is characterized in that the data recorded on the tape is read at intervals of several frames, and the core frame data is reconstructed and reproduced.