GB1457452A - Television signals - Google Patents
Television signalsInfo
- Publication number
- GB1457452A GB1457452A GB5449373A GB5449373A GB1457452A GB 1457452 A GB1457452 A GB 1457452A GB 5449373 A GB5449373 A GB 5449373A GB 5449373 A GB5449373 A GB 5449373A GB 1457452 A GB1457452 A GB 1457452A
- Authority
- GB
- United Kingdom
- Prior art keywords
- bits
- bit
- parity
- line
- word
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
- H04N7/084—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the horizontal blanking interval only
- H04N7/085—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division with signal insertion during the horizontal blanking interval only the inserted signal being digital
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
- H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
- H04N21/235—Processing of additional data, e.g. scrambling of additional data or processing content descriptors
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
- H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
- H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
- H04N21/238—Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
- H04N21/2383—Channel coding or modulation of digital bit-stream, e.g. QPSK modulation
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Television Systems (AREA)
Abstract
1457452 Television BRITISH BROADCASTING CORP 25 Nov 1974 [23 Nov 1973] 54493/73 Heading H4F A television signal in digital form is modified to include an error protection (i.e. parity) bit for each digital word (e.g. for each eight-bit word representing a picture sample), and selected bits (e.g. the parity bits or the least significant bit of each word) are inserted into at least some of the blanking intervals in the signal (e.g. into the horizontal blanking intervals). In this way the parity bits are added to the television signal without increasing the gross bit rate. Preferably the line sync. pulse and colour burst in the blanking intervals are removed before the selected bits are inserted, although the selected bits may be inserted at the times marked P in Fig. 2, i.e. during the stationary levels of the line blanking period. The bits of the television signal are delayed in line store 12 by approximately one line period relative to the error protection (parity) bits associated with that line before being applied to a transmission or processing channel 22, the 704 parity bits for the 704 eight-bit words being formed into 88 eight-bit words in store 13. Each parity bit is formed in generator 11 by the resultant of adding modulo-2 all or at least the more significant of the bits of the associated eight-bit word. The line store 12 may be situated at the receiver between switch 15 and error protection check circuit 18. If transmission is as in Fig. 2 then a D-A converter 20 may be connected to feed a colour decoder and monitor 21.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5449373A GB1457452A (en) | 1973-11-23 | 1973-11-23 | Television signals |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5449373A GB1457452A (en) | 1973-11-23 | 1973-11-23 | Television signals |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1457452A true GB1457452A (en) | 1976-12-01 |
Family
ID=10471185
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB5449373A Expired GB1457452A (en) | 1973-11-23 | 1973-11-23 | Television signals |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1457452A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3443041A1 (en) * | 1984-11-26 | 1986-05-28 | Siemens AG, 1000 Berlin und 8000 München | Method for improving the transmission quality of PCM coded image signals |
-
1973
- 1973-11-23 GB GB5449373A patent/GB1457452A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3443041A1 (en) * | 1984-11-26 | 1986-05-28 | Siemens AG, 1000 Berlin und 8000 München | Method for improving the transmission quality of PCM coded image signals |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCPE | Delete 'patent ceased' from journal |
Free format text: 5132, PAGE 1711 |