Caption display method for using digital video system

• US 5,999,225 A
• Filed: 08/01/1996
• Issued: 12/07/1999
• Est. Priority Date: 08/02/1995
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Iwamura, Ryuichi, Yagasaki, Yoichi, Fujinami, Yasushi
• Primary Examiner(s): LEE, RICHARD J
• Application Number:
  US08/683,684
• Time in Patent Office: 1,223 Days
• Field of Search: 348/384, 348/390, 348/423, 348/461, 348/563-565, 348/467, 348/468, 348/569, 386/33, 386/45, 386/95, 386/111-112, 386/125-126
• US Class Current: 348/564
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/431 Generation of visual interfaces for content selection or interaction; Content or additional data rendering
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/4884 for displaying subtitles
• CPC Class Codes: H04N 21/6547 comprising parameters, e.g. for client setup
• CPC Class Codes: H04N 21/8153 comprising still images, e.g. texture, background image

Abstract

A method and apparatus for encoding signals so as to form a multiplexed signal and for decoding the same. The apparatus may include an encoding unit and a decoding unit. The encoding unit may include a device for encoding a dynamic image signal so as to form a video bit stream, a device for encoding superimposed data so as to form bit map data, a device for encoding the bit map data and coordinates of a plurality of regions so as to form a bit stream of each respective region, a device for encoding the bit stream of each of the regions and coordinates of a page layer so as to form a bit stream of a page layer. The page layer specifies information indicative of start and end positions of a plurality of regions such that each of the regions are within a display area, and a device for multiplexing the bit stream of the page layer and the video bit stream. The decoding unit may include a device for separating the multiplexed bit stream into the video bit stream and the superimposed data bit stream, a device for decoding the video bit stream so as to form the dynamic image signal, a device receiving the superimposed data bit stream for obtaining coordinates of a page layer, coordinates of a plurality of regions and bit map data therefrom and for decoding the bit map data, a device for selecting one of the decoded bit map data and the dynamic image signal, and a control device.

Claims

1. An encoding apparatus for generating a multiplexed bit stream, comprising:

means for encoding a dynamic image signal so as to form a video bit stream;

means for encoding superimposed data so as to form bit map data;

means for encoding said bit map data and region coordinates of a plurality of regions of a first page so as to form a bit stream of each respective region;

means for encoding the bit stream of each of said regions and page coordinates of a page layer, said page coordinates being associated with said region coordinates, so as to form a bit stream of a page layer wherein said page coordinates establish a display area where said first page is displayable to enable a decoding apparatus which is responsive to an external page movement command, to determine a superimposed data display position by determining a movement offset on the basis of the page movement command, and clipping the movement offset based on the determined movement offset and the page coordinates, such that each of said regions is always displayed on a display even if the determined movement offset is operative to move a smaller, second page to a periphery of the display, and would otherwise move a portion of the first page off the display; and

multiplexing means for multiplexing the bit stream of said page layer and said video bit stream into a multiplexed bit stream.

2. An encoding apparatus according to claim 1, wherein said page layer defines a rectangular area including all said regions belonging to said page layer.

3. The encoding apparatus of claim 1 wherein said first and second pages are each captions of said dynamic image signal.

4. A decoding apparatus for decoding a multiplexed bit stream, comprising:

separating means for separating said multiplexed bit stream into a video bit stream and a superimposed data bit stream, in which said superimposed data bit stream includes information representative of a page layer which contains page coordinates associated with a first page that establish a display area where the first page is displayable, said page layer also containing region coordinates indicative of start and end positions of a plurality of regions of said first page within boundaries of said display area;

means for decoding said video bit stream so as to form a dynamic image signal;

means for receiving said superimposed data bit stream for obtaining therefrom said page coordinates, said region coordinates and bit map data and for decoding said bit map data;

means for selecting one of the decoded bit map data and the dynamic image signal; and

means for determining a superimposed data display position for said first page on the basis of an externally supplied page movement command, by determining a movement offset on the basis of the page movement command, and clipping the movement offset based on the determined movement offset and at least one of the page coordinates and the region coordinates, such that each of said regions is displayed on a display even if the determined movement offset causes a smaller, second page to move to a periphery of the display, and the determined movement offset would otherwise move a portion of the first page off the display.

5. The decoding apparatus of claim 4 wherein said first and second pages are each captions of said dynamic image signal.

6. An encoding method comprising the steps of encoding a dynamic image signal so as to form a video bit stream;

encoding a superimposed data bit stream so as to form bit map data, encoding said bit map data and region coordinates of a plurality of regions of a first page so as to form a bit stream of each respective region, encoding the bit stream of each of said regions and page coordinates of a page layer, said page coordinates being associated with said region coordinates, so as to form a bit stream of said page layer wherein said page coordinates establish a display area where said first page is displayable to enable a decoding apparatus which is responsive to an external page movement command, to determine a superimposed data display position by determining a movement offset on the basis of the page movement command, and clipping the movement offset based on the determined movement offset and the page coordinates, such that each of said regions is always displayed on a display even if the determined movement offset is operative to move a smaller, second page to a periphery of the display, and would otherwise move a portion of the first page off the display, and multiplexing the bit stream of said page layer and said video bit stream into a multiplexed bit stream.

7. An encoding method according to claim 6, wherein said page layer defines a rectangular area including all said regions belonging to said page layer.

8. The encoding method of claim 6 wherein said first and second pages are each captions of said dynamic image signal.

9. A record medium for recording a multiplexed bit stream formed from a video bit stream and a bit stream of a page layer, in which the video bit stream is obtained by encoding a dynamic image signal and in which the bit stream of the page layer is obtained by encoding a bit stream of each of a plurality of regions of a first page and page coordinates of the page layer, the bit stream of each respective region being obtained by encoding region coordinates of the plurality of regions and bit map data which is obtained by encoding superimposed data, said page coordinates being associated with said region coordinates, wherein said page coordinates establish a display area where said first page is displayable to enable a decoding apparatus which is responsive to an external page movement command, to determine a superimposed data display position by determining a movement offset on the basis of the page movement command, and clipping the movement offset based on the determined movement offset and the page coordinates, such that each of said regions is always displayed on a display even if the determined movement offset is operative to move a smaller, second page to a periphery of the display, and would otherwise move a portion of the first page off the display.

10. The record medium of claim 9 wherein said first and second pages are each captions of said dynamic image signal.

11. A transmitting method for transmitting a multiplexed bit stream formed from a video bit stream and a bit stream of a page layer, in which the video bit stream is obtained by encoding a dynamic image signal and in which the bit stream of the page layer is obtained by encoding a bit stream of each of a plurality of regions of a first page and page coordinates of the page layer, the bit stream of each respective region being obtained by encoding region coordinates of the plurality of regions and bit map data which is obtained by encoding superimposed data, said page coordinates being associated with said region coordinates, wherein said page coordinates establish a display area where said first page is displayable to enable a decoding apparatus which is responsive to an external page movement command, to determine a superimposed data display position by determining a movement offset on the basis of the page movement command, and clipping the movement offset based on the determined movement offset and the page coordinates, such that each of said regions is always displayed on a display even if the determined movement offset is operative to move a smaller, second page to a periphery of the display, and would otherwise move a portion of the first page off the display.

12. The transmitting method of claim 11 wherein said first and second pages are each captions of said dynamic image signal.

13. A decoding method for decoding a multiplexed bit stream, comprising:

separating said multiplexed bit stream into a video bit stream and a superimposed data bit stream, in which said superimposed data bit stream includes information representative of a page layer which contains page coordinates associated with a first page that establish a display area where the first page is displayable, said page layer also containing region coordinates indicative of start and end positions of a plurality of regions of said first page within boundaries of said display area;

decoding said video bit stream so as to form a dynamic image signal;

receiving said superimposed data bit stream to obtain therefrom said page coordinates, said region coordinates and bit map data, and decoding said bit map data;

determining a superimposed data display position for said first page on the basis of an externally supplied page movement command, by determining a movement offset on the basis of the page movement command, and clipping the movement offset based on the determined movement offset and at least one of the page coordinates and the region coordinates, such that each of said regions is displayed on a display even if the determined movement offset causes a smaller, second page to move to a periphery of the display, and the determined movement offset would otherwise move a portion of the first page off the display.

14. The method of claim 13 wherein said first and second pages are each captions of said dynamic image signal.