KR100509901B1 - How to Provide Subtitles in Teletext - Google Patents

Abstract

If many subtitle pages on the same channel are sent to provide several languages,

-Keep page numbers flexible to the language,

-Provide viewers with an easy way to request subtitle pages by selecting only the language name,

After changing the channel, the intelligent decoder needs to find the previously selected subtitle page simply by storing only the language number.

All pages containing subtitle information in different kinds of languages will be listed in one table called the Initial Subtitle Table (IST). The IST contains language names, language numbers, and page numbers that will be required up to 15 languages and can be displayed as regular teletext pages. Language numbers 1 to 15 may be stored as channel parameters that indirectly store the appropriate page numbers for each channel to enable very economical use of the EEPROM. After the channel changes the page, transferring subtitle information in the desired language will be automatically requested via the stored language number to refer to the IST page. Any new subtitle language can be selected using an IST page and a simple viewer interface, ie a vertical cursor.

An improved error detection method is performed for transmitting language numbers and page numbers; Two variants of the digits associated with the original and complementary signals are transmitted.

Using this system, it is easy to select subtitles for each available language and the decoder spends less.

Description

How to provide subtitles in teletext

The present invention relates to a method for providing subtitles in a teletext system for a television receiver. More specifically, the present invention relates to a method for providing subtitles in a teletext system for a television receiver in accordance with World Standard Teletext (WST). This teletext system applies directly to 625/50 television systems and is used in European Phase Alternating Line (PAL) television systems.

If many subtitle pages are sent to provide several languages on the same channel, there is a need for:

Maintain flexibility in assigning page numbers to languages.

-Provide viewers with an easy way to request subtitle pages by selecting only language names.

-After the channel is changed, the intelligent decoder will only save the language number so that the previously selected subtitle page can be found.

It is an object of the present invention to disclose a method for providing subtitles in a teletext system. This object is achieved by the method disclosed in claim 1.

All pages containing subtitle information in other languages are listed in one or more tables called the Initial Subtitle Table (IST).

The IST contains a language name, language number, and page number that can be requested up to 15 languages, and is displayed as a regular teletext page. Language numbers 1 to 15 are stored as channel parameters that indirectly store a suitable subtitle-page number for each channel to enable economical use of the EEPROM.

After changing the channel, the user acquires a desired page by requesting a page carrying subtitle information of a desired language by referring to the IST page through the stored language number.

Any new subtitle language is selected using the IST page and a simple user interface, ie by entering the displayed language number.

An improved error detection method has been implemented for transmitting language and page numbers, which is to send two versions of the relevant digits: the original number and the complement signal. To meet both East-West European languages, two different IST pages must be sent, each containing a list of individual languages.

Hereinafter will be described an embodiment of the present invention.

IST page

IST pages for Western Europe are specified to be sent as page numbers # 1F9,0000 or # 1F9,3F7F as test codes and for Eastern Europe at page numbers # 1F8,0000 or # 1F8,3F7F. Any additional ISTs representing other language categories have page numbers 1F7, 1F6, ... and so on. All pages contain up to 17 additional headers.

Relationship between decoder devices and ISTs

A receiver with a Western European decoder only searches for IST1 (IF9). Receivers with Eastern European decoders only search for IST2 (1F8). Receivers with Western- and Eastern European decoders search for both IST1 (1F9) and IST2 (1F8).

Organization of IST Pages

Table 1. Components of an IST page

Recommendation:

a) Each row must contain two BOX-ON characters as part of an identification code sequence (ID) that provides the same conditions for IST display and subtitles to simplify decoder hardware.

b) Rows 1 and 2 are used only for messages informing the viewer how to interpret the IST (row-N).

Row 1 should indicate that the IST will actually be used for the current channel setup.

Row 2 should indicate that the IST will actually be used for default channel setup.

c) Headers of all IST pages should always be suppressed. Here, "inhibited" means that it is not displayed on the display. Control bit C7 is set to one.

Organization of Row I

Table 2. Components of row-I

Recommendation:

In order to accelerate the decoder software, it is desirable to place a separate field of each row-I in the same column as the test code.

Organization of Row-N

Table 3. Components of Row-N

Recommendation:

Rows 1 and 2 are used for the message (row-N) that tells the viewer how to interpret the IST.

Row 1 should indicate that the IST will actually be used for the current channel setup.

Row 2 should indicate that the IST will actually be used for default channel setup.

Do not use control code box off (OA) between characters (06) and (38) in line-N.

Table 4. Components of FS (Field-Separator) and ID-I, ID-N (Identifier)

Table 5. Decoder Overriding Field-Separator

Table 6. Code Conversion Table

Example 1:

Row-I sent:

00 1D 0B 0B 18 4F 48 07 20 30 37 07 20 45 4E 47 4C 49 53 48 20 20 07 20 20 20 20 59 45 53 20 18 32 31 30 4D 4E 4F 0A 0A

Interpretation at the decoder:

00 1D 0B 0B 18 Row-I identifier. Background = Black

4F 48 "07" Repair "OH"

07 Field Separator. Fore Color = White

20 30 37 Language code = "07" (＄ 20 is ignored)

07 Field Separator. Fore Color = White

20 45 4E 47 4C 49 53 48 20 20 String = "ENGLISH"

07 Field Separator. Fore Color = White

20 20 20 20 59 45 53 20 String = "YES"

18 Field Separator = Concealed

32 31 30 4D 4E 4F Page number = "210" and inverted page

Number = "MNO"

Exit code for line 0A0A = box on, box off.

Claims (10)

A method for providing subtitles in a desired language at a television receiver, in which a subtitle page according to a teletext standard is received, and the page numbers of subtitle pages containing subtitles in other languages are listed in one or more subtitle tables, wherein Receiving a caption table including a language indication of respective caption pages as a teletext signal in accordance with a teletext standard; And Selecting a subtitle page in a desired language using the subtitle table and the display of the language. The method of claim 1, wherein the subtitle table includes language names, language numbers, and page numbers expressed in up to 15 languages on request, and is displayed as a regular teletext page. 3. The method of claim 1 or 2, wherein the language number is stored as a channel parameter indirectly storing an appropriate subtitle page number for each channel, thereby enabling a very economical use of the EEPROM at the receiving device. The method of claim 1 or 2, wherein after the channel is changed, a subtitle providing method is automatically requested with reference to the subtitle table page through a language number in which a subtitle page carrying subtitle information in a desired language is stored. 3. The method of claim 1 or 2, wherein a new subtitle language is selected by inputting a language number using the subtitle table page and the viewer interface. A method of transmitting a subtitle page in another language, wherein the subtitle page is transmitted as a teletext signal in accordance with the teletext standard, One or more subtitle pages are transmitted as a teletext signal in accordance with a teletext standard, wherein the page numbers of the subtitle pages with subtitles in different languages are created in the subtitle table, the subtitle table including an indication of the language of each subtitle page. How to send a subtitle page. 7. A method according to claim 6, wherein two versions of the original digit and the complement digit are transmitted in order to transmit the language number and the page number. 8. A method according to claim 6 or 7, wherein two different subtitle table pages, each containing a list of individual languages, are transmitted to satisfy both Eastern and Western European languages. A subtitle table page for Western Europe is sent with a page number # 1F9,0000 or # 1F9,3F7F, and a subtitle table page for Eastern Europe is sent with a page number # 1F8,0000 or # 1F8,3F7F. How to send the page. 10. A method according to claim 9, wherein additional subtitle table pages representing different language categories have page numbers 1F7, 1F6 ... and so on.