Multiplex communications – Communication techniques for information carried in plural... – Assembly or disassembly of messages having address headers
Reexamination Certificate
1997-05-23
2001-05-15
Nguyen, Chau (Department: 2663)
Multiplex communications
Communication techniques for information carried in plural...
Assembly or disassembly of messages having address headers
C370S476000, C370S516000, C370S538000
Reexamination Certificate
active
06233253
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to digital signal processing and in particular to the conversion of data from different input sources and different input formats to form a digital bitstream for output in a selected output format.
BACKGROUND
Homes and workplaces receive different types of data in different data formats for a variety of applications. For example, a home may receive data from satellite or terrestrial sources comprising High Definition Television (HDTV) broadcasts, Multi-point Microwave Distribution System (MMDS) broadcasts, and Digital Video Broadcasts (DVB). A home may also receive data via telephone (e.g. the Internet) and coaxial lines (e.g. cable TV) and from domestic sources such as PCs, Digital Video Disk (DVD), CDROM, VHS and Digital VHS (DVHS™) type players and many other types of sources. Consequently, there is an increasing need for a Conversion system capable of accepting data in different data formats, from a plurality of different sources and that is capable of merging the data and converting it to a selected output data format for transmission on a selected transmission channel. Such a Conversion system is needed to support data processing activities including editing, storage and transmission for multi-media applications.
In such a Conversion system, the input data from multiple sources is in the form of packetized digital data. Input data from other sources e.g. analog video broadcasts, is converted into packetized digital data for processing in the Conversion system. However, there are a number of problems in merging and converting multimedia packetized digital data from different input format sources into a selected output data format. For example, an important factor in determining the way data from one or more different input sources may be merged and re-packetized is the range of data rates that is permitted by a receiving device or by the coding requirements of the desired output signal format.
The desired output data format typically imposes both a minimum and a maximum data rate limit in order to prevent underflow or overflow of an input data buffer in a receiving device. The data rate of the output format is also constrained by the bandwidth characteristics of the transmission channel. Consequently, it is necessary to re-code and re-packetize the input data in a manner that meets these data rate constraints. Other constraints on the format conversion of multimedia input data arise from differences in coding characteristics between the input data format and desired output data format. These coding characteristics include timing, error correction, conditional access and coding type characteristics. The problems involved in merging and converting digital data from different input format sources into a selected output data format are addressed by a system according to the present invention.
SUMMARY
In accordance with the principles of the present invention, a Conversion system merges and converts data in a plurality of different data formats from a plurality of different sources, to a selected output data format for transmission on a selected transmission channel. The Conversion system re-codes and re-packetizes the input data to include timing, error correction, conditional access and coding type parameters compatible with the selected output format. The Conversion system also outputs data at a data rate compatible with selected data format, receiving device and transmission channel characteristics.
A method for digital data format conversion involves depacketizing an input packetized datastream. A timing recovery parameter is formed in response to a desired output format. The depacketized data is re-packetized in response to the desired output format and the timing recovery parameter is incorporated in the re-packetized data. The re-packetized data is multiplexed in response to the selected format and provided to an output channel.
REFERENCES:
patent: 4808008 (1989-02-01), Guerillot
patent: 4819226 (1989-04-01), Beckner et al.
patent: 5381181 (1995-01-01), Deiss
patent: 5467137 (1995-11-01), Zdepski
patent: 5481543 (1996-01-01), Veltman
patent: 5541919 (1996-07-01), Yong et al.
patent: 5581706 (1996-12-01), Jessup, Jr. et al.
patent: 5598415 (1997-01-01), Nuber et al.
patent: 5652749 (1997-07-01), Davenport et al.
patent: 5691986 (1997-11-01), Pearlstein
patent: 5757416 (1998-05-01), Birch et al.
patent: 5802068 (1998-09-01), Kudo
patent: 5819034 (1998-10-01), Joseph et al.
patent: 5862153 (1999-01-01), Kikuchi et al.
patent: 6081526 (2000-06-01), Saeijs et al.
patent: 755 157A2 (1997-01-01), None
patent: 762 684 A2 (1997-03-01), None
patent: 837 609A2 (1998-04-01), None
patent: 95/26595 (1995-10-01), None
patent: 96/08911 (1996-03-01), None
patent: 98/16067 (1998-04-01), None
S.Defrance,Switching MPEG 2, Jan. 16, 1995, pp. 7/1-7/3, The Institution of Electrical Engineers England.
O. Bungum,Transmultiplexing, Transcontrol and Transscrambling Of MPEG-2/DVB Signal, pp. 288-293, International Broadcasting Conf. Sep. 12-16, 1996.
Digital Bitstream Generator For Testing MPEG Video Decoders, by T. Settle et al, I.E.E.E. Transactions on Consumer Electronics, vol. 42, No. 3, Aug. 1996.
Bridgewater Kevin Elliott
Horlander Thomas Edward
Lu Ligang
Settle Timothy Forrest
Kurdyla Ronald H.
Laks Joseph J.
Nguyen Chau
Thomson Licensing S.A.
Trinh D.
LandOfFree
System for digital data format conversion and bit stream... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System for digital data format conversion and bit stream..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System for digital data format conversion and bit stream... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2553060