Processing digital data having variable packet lengths

Abstract

When macro blocks (MB0 to MB9) each of which has a variable length are input for one picture, null syncs (NULL1 to NULL5) each of which has a unit length are generated corresponding to the format of video data to be handled. Each null sync contains length information and a data portion. The length information represents 0. The data portion is filled with data [00]s. Corresponding to the length information, an overflow portion of a macro block is detected. The overflow portion is successively packed to macro blocks each of which is smaller than the unit length. Thus, each macro block is packed in the unit length. Since the length information of each null sync represents 0, the overflow portions are packed after the length information of each null sync. With null syncs, one format of video data can be matched with another format. In addition, with null syncs, overflow portions are packed. Thus, the record medium can be effectively used.

Description

TECHNICAL FIELD [0001] The present invention relates to a data processing apparatus, a data processing method, a recording apparatus, and a recording method that are suitable for use in a broadcasting station and that allow video signals of a plurality of different formats to be integrally handled. RELATED ART [0002] In recent years, as digital broadcasts have been started, various picture formats have been proposed. In addition to a conventional 29.97 Hz (frame frequency), 480 line×320 pixel (number of effective lines×number of effective horizontal pixels) interlace-scanned format and a conventional 25 Hz (frame frequency), 576 line×384 pixel interlace-scanned format, more than ten different formats as combinations of data rates of video signal (25 Mbps), scanning modes (interlaced or progressive), and frame frequencies (23.976 Hz, 25 Hz, 29.97 Hz, 50 Hz, and 59.94 Hz) have been proposed. [0003] As various picture formats have been proposed, a so-called multi-rate type video tape r...

AI Technical Summary

Benefits of technology

[0011] Therefore, an object of the present invention is to provide a data processing apparatus, a data processing method, a recording apparatus, and a recording method that allow a record medium to be effectively used with dummy sync blocks and a digital video signal to be recorded in high quality.

Problems solved by technology

Thus, it is very difficult to select an optimum length of each sync block corresponding to each of a plurality of formats.

In addition, conventionally, a signal processing circuit that handles a plurality of formats cannot be accomplished with a single structure.

Consequently, the circuit scale of the multi-rate video tape recorder becomes large and thereby the cost thereof rises.

Consequently, since the data rate cannot be flexibly varied corresponding to the multi-rates, the multi-rate video tape recorder cannot be accomplished.

When a digital video signal is recorded in high quality, even if the digital video signal is compression-encoded with variable length code, the amount of data recorded on a record medium becomes large.

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