Data stream multiplexing apparatus and method, and record medium therefor

Claim 2

A data stream multiplexing apparatus as claimed in claim 1, wherein the stream modifying means additionally locates the second sub-picture data unit on the sub-picture data stream as it splits the display time period of the first sub-picture data unit to a plurality of almost equal display time periods.

Claim 3

A data stream multiplexing apparatus as claimed in claim 1, wherein the stream modifying means additionally locates the second sub-picture data unit on the sub-picture data stream as the sum of the data amount of the modified sub-picture data stream and the data amount of picture data stream which are other data streams per unit time is averaged.

Claim 4

A data stream multiplexing apparatus as claimed in any one of claims 1 through 3, wherein the data stream modifying means produces the modified sub-picture data stream when the display time period of the first sub-picture data unit exceeds a specific value.

Claim 5

A data stream multiplexing apparatus, comprising: separating means responsive to input sub-picture data streams located along its time axis with first sub-picture data unit having pixel data forming the sub-picture image with a preset display time period and control data for controlling the display of the sub-picture image in accordance with a display time, for separating the pixel data and the control data; control data splitting means for splitting the control data units separated by the separating means; stream modifying means for producing modified sub-picture data stream from a sub-picture data stream where a first sub-picture data unit containing pixel data forming a sub-picture image with a preset display time period is located along a time axis by additionally locating at least one of second sub-picture data unit having almost same contents as the first sub-picture data unit within the display time period of the first sub-picture data unit on the sub-picture data stream; and multiplexing means responsive to input modified sub-picture data stream produced by the stream modifying means and other data streams reproduced in synchronous with the modified sub-picture data stream, for multiplexing these streams after packetizing them by a prescribed length.

Claim 6

A data stream multiplexing apparatus as claimed in claim 5, wherein the control data splitting means splits the control data by almost equal data amounts.

Claim 7

A data stream multiplexing apparatus as claimed in claim 5, wherein the control data splitting means splits the control data units by almost equal display control time periods.

Claim 8

A data stream multiplexing method, comprising the steps of: producing a modified sub-picture data stream from a sub-picture data stream located along its time axis with a first sub-picture data unit containing pixel data forming a sub-picture image with a preset display time period by additionally locating at least one of second sub-picture data units having almost same contents as the first sub-picture data unit within the display time period of the first sub-picture data unit on the sub-picture data stream; and multiplexing the modified sub-picture data streams and other data streams reproduced in synchronous with the modified sub-picture data stream after packetizing them by a prescribed length.

Claim 9

A data stream multiplexing method as claimed in claim 8, wherein the second sub-picture data unit is additionally located on the sub-picture data stream to split the display time period of the first sub-picture data unit by almost equal display time periods.

Claim 10

A data stream multiplexing method as claimed in claim 8, wherein the second sub-picture data unit is additionally located on the sub-picture data stream to average the sum of the data amounts per unit time of the modified sub-picture data streams and the other picture data streams.

Claim 11

A data stream multiplexing method as claimed in any one of preceeding claims 8 through 10, wherein the modified sub-picture data stream is produced when the display time period of the first sub-picture data unit exceeds a specific value.

Claim 12

A data stream multiplexing method, comprising the steps of: separating the pixel data and the control data, in response to input sub-picture data streams located along its time axis with first sub-picture data unit having pixel data forming the sub-picture image with a preset display time period and control data for controlling the display of the sub-picture image in accordance with a display time; spliting the separated control data in units; coupling the control data units with the pixel data to form some second sub-picture data units; producing a modified sub-picture data streams from a sub-picture data stream where a first sub-picture data unit containing pixel data forming a sub-picture image with a preset display time period is located along a time axis by additionally locating at least one of second sub-picture data unit having almost same contents as the first sub-picture data unit within the display time period of the first sub-picture data unit on the sub-picture data stream; and multiplexing the modified sub-picture data streams with other data streams reproduced in synchronous with the modified sub-picture data stream after packetizing them by a prescribed length.

Claim 13

A data stream multiplexing method as claimed in claim 12, wherein the control data units are split by almost equal data amounts.

Claim 14

A data stream multiplexing method as claimed in claim 12, wherein the control data units are split by almost equal display control time periods.

Claim 15

A record medium for recording a sub-picture data stream located along its time axis with sub-picture data units containing pixel data forming a sub-picture image with a preset display time period and other data streams reproducible in synchronous with the sub-picture data stream by m ultiplexing them after packetizing them by a prescribed length, characterized by that at least a part of a plurality of consecutive sub-picture data units located on the multiplexed streams by packetizing includes a preceeding first sub-picture data unit and a second sub-picture data unit with packets located in the display time period of the first sub-picture data unit, the first and second sub-picture data units have the same pixel data, and the display time periods are substantially contiguous.

Claim 16

A record medium for recording sub-picture data streams located along its time axis with first sub-picture data unit having pixel data forming the sub-picture image with a preset display time period and control data for controlling the display of the sub-picture image in accordance with a display time and other data streams reproducible in synchronous with the sub-picture data stream by maultiplexing them after packetizing them by a prescribed length, wherein at least a part of a plurality of consecutive sub-picture data units located on the multiplexed streams by packetizing includes a preceeding first sub-picture data unit and a second sub-picture data unit with packets located in the display time period of the first sub-picture data unit, the first and second sub-picture data units have the same pixel data, and the valid time periods of the display time periods are substantially contiguous.

Claim 17

A record medium as claimed in claim 16, wherein the size of the display control data of the first sub-picture data unit and that of the second sub-picture data unit are almost same.

Claim 18

A record medium as claimed in claim 16, wherein the valid time period of the display control data of the first sub-picture data unit and that of the second sub-picture data unit are almost same.