Television – Nonpictorial data packet in television format – Data format
Patent
1994-09-15
1997-08-19
Peng, John K.
Television
Nonpictorial data packet in television format
Data format
348476, 348478, H04N 7087
Patent
active
056593686
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to the processing of auxiliary video information that may be present in a video signal during vertical blanking and overscan intervals. A video signal typically includes vertical display intervals, or fields, having a plurality of horizontal line intervals, e.g. 262.5 lines per field in NTSC video systems. The beginning of each vertical and horizontal interval is identified by respective vertical and horizontal sync pulses that are included in a composite video signal. A portion of each vertical interval is a vertical blanking interval that is not normally intended for display. In addition, several line intervals adjacent to the vertical blanking period may be within an overscan region of a video display and will not be visible.
The lack of image information intended for display during blanking and overscan intervals makes it possible to insert an auxiliary information component, e.g. teletext or closed caption (CC) data, into these intervals. Closed caption data represents speech or other sounds in the audio portion of the video program. The closed caption data is displayed in a portion of the video display simultaneously with the corresponding video program display to serve as an aid for hearing impaired viewers. Standards such as Federal Communications Commissions (FCC) Regulations define the format for each type of auxiliary information including the location of the information within a vertical interval. For example, the present closed captioning standard (see e.g. 47 CFR .sctn..sctn. 15.119 and 73.682) specifies a closed caption signal must occur during line 21 of field 1 in the format shown in FIG. 1.
Referring to FIG. 1, the closed caption signal includes a run-in clock (RIC) signal that occurs during the first half of line 21. The RIC signal is used as described below to facilitate the extraction of the closed caption data that occurs during a data interval in the last half of line 21. A signal transition at the beginning of a "start bit" interval shown in FIG. 1 indicates the beginning of the data interval. The start bit interval is followed by a signal during the remainder of the data interval that represents 16 bits of binary information. Each of the start bit and binary bit intervals is approximately 2 .mu.s in duration. The 16 binary bits represent two 8-bit character codes in the case of closed caption data. Each character code includes a 7-bit ASCII code and a parity bit.
The FCC standard further specifies that the closed caption signal may include two "channels" of closed caption data designated C1 and C2, and two "channels" of text data designated T1 and T2. Whether data in the closed caption signal is associated with C1, C2, T1, or T2 is determined by control codes that are included in the data. These control codes are listed at 47 CFR .sctn.15.119. Two channels of closed caption data make it possible to provide closed captioning in two languages. For example, captioning in English is on C1 and captioning in Spanish is on C2. Because speech is not continuous in a video program, the second language information can be inserted into the closed caption signal during intervals when speech is not occurring. The T1 and T2 text channels provide similar dual-language capability for the display of text that may be unrelated to the audio portion of the video program.
United States law requires that all television receivers 13 inches and larger in size that are sold in the U.S. after 1 Jul. 1993 must be capable of decoding a closed caption signal (see 47 CFR .sctn.15.119). This requirement adds to the cost and complexity of most televisions. Many television users, particularly individuals who are not hearing impaired, may not wish to utilize the closed caption capability. Thus, television manufacturers must invest in the development of a feature that is of value to only a limited number of individuals who purchase televisions. In addition, many individuals will be compelled to pay for a feature that is of little or no value to them.
The embodiment of the present inventi
REFERENCES:
patent: 4203130 (1980-05-01), Doumit et al.
patent: 4706121 (1987-11-01), Young
patent: 4862268 (1989-08-01), Campbell et al.
patent: 5210611 (1993-05-01), Yee et al.
patent: 5260788 (1993-11-01), Takano et al.
patent: 5343239 (1994-08-01), Lappington et al.
Federal Communications Commission (FCC), 47 CFR CH.I PAR. 73.682 10 Jan. 1992, pp. 192-198 "TV Transmission Standards".
European Broadcasting Union. Tech. 3262-E, Aug. 1990, Geneva pp. 1-44 "Specification of the Domestic Video Programme Delivery Control System (PDC)".
Rpt. E-7709-C Television Captioning for the Deaf: Signal and Display Specifications--J. Lentz et al, Revised May 1980.
Draft/North American Broadcast Teletext Specification (NABTS) .COPYRGT. Sep. 20, 1963--EIA/CVCC.
Television Data System for Program Identification by D.K. Broberg Apr. 12, 1992, NAB 1992 Broadcast Engineering Conf. Proceedings.
Decoder IC For An Automatic Video Program Identification System (VPS) By Xaver Meindl, et al.--IEEE Transaction on Consumer Electronics, vol. CE-32 Aug. 1986.
Videotext Programs Video Home Sets (VPV).sup.1 -vol. 30 (1986).
Rundfunktechnische Mitteilungen, 1985 by Heller, "VPS-A New System for Presentation Controlled Program Recording".
Emanuel Peter M.
Flynn Nathan J.
Peng John K.
Shedd Robert D.
Thomson Consumer Electronics Inc.
LandOfFree
Auxiliary video information system including extended data servi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Auxiliary video information system including extended data servi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Auxiliary video information system including extended data servi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1108373