Picture encoding method, picture encoding apparatus and picture recording medium

Abstract

This invention employs a scheme to allow an input video signal to undergo encoding, e.g., predictive encoding, DCT processing quantization at fixed quantization step size and variable length encoding to generate first encoded data to determine (calculate) allocated code quantity every frame or every GOP on the basis of data quantity every predetermined time, e.g., every frame or every GOP of the first encoded data and total quantity of usable data to encode the input video signal every predetermined time on the basis of the allocated code quantity to generate second encoded data. Thus, variable rate encoding such that encoding rate changes every predetermined time is realized. As a result, even if pictures (frames) of complicated are successive, there is no possibility that quantization step size is caused to be large with respect to these pictures as in the conventional apparatus. Thus, uniform high picture quality can be obtained through the entirety. Further, since second encoded data obtained in a manner as described above has variable rate, in the case where such encoded data is recorded onto picture recording media, limited memory capacity can be effectively used, and recording time of picture recording media can be prolonged. In addition, picture data of high picture quality uniform over the entirety can be reproduced from the picture recording media.

Description

[0001]Notice: More than one reissue application has been filed for the reissue of U.S. Pat. No. 5,703,646. The reissue applications are Ser. No. 09 / 474,479 and the instant continuation application.[0002]This application is a continuation of application Ser. No. 08 / 351,262, filed as PCT / JP94 / 00610 Apr. 11, 1994 published as WO94 / 24822 Oct. 27, 1994, now abandoned.TECHNICAL FIELD[0003]This invention relates to a picture encoding method, a picture encoding apparatus and a picture recording medium, and more particularly to a picture encoding method, a picture encoding apparatus and a picture recording medium which are used in a system for implementing encoding for storage to a video signal of moving picture to record the coded signal onto a picture recording medium such as an optical disc, a magnetic disc, or a magnetic tape, etc. or a system for transmitting a video signal of moving picture through a transmission path.BACKGROUND ART[0004]Hitherto, in a system for transmitting a video s...

AI Technical Summary

Benefits of technology

This approach ensures consistent high picture quality across all frames by dynamically adjusting encoding rates, optimizing data usage, and prolonging recording times on limited media capacities.

Problems solved by technology

Accordingly, in the conventional apparatus, when complicated pictures are successive, quantization step size is caused to be larger, so picture quality is deteriorated, while when simple pictures are successive, quantization step size is caused to be smaller.

As a result, uniform picture quality cannot be obtained through the entirety.

In addition, in the case of recording bit stream onto a picture recording medium of a limited data capacity, in order to avoid extreme deterioration of picture quality with respect to pictures of complicated pattern, a fixed rate of high rate such that picture quality of such complicated picture is not injured must be applied to the entirety, resulting in decreased recording time.

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