Scientific-atlanta, Inc.

Paul D Nicholas

Christopher H Birch

Steven S Lawrence

Christian V Van Staden

Walter R Brooks

Tsai Lo

Randy K Munich

Baldwin Chieh

Kenn Heinrich

A method and apparatus for manipulating and de-manipulating Vertical Blanking Interval (VBI) data having any one of a plurality of formats, comprising an encoder, a transmission medium and a decoder. The encoder receives the VBI data having an original data format and manipulates the format of the VBI data into a general VBI format. This signal is transferred to the decoder where the decoder de-manipulate the general VBI format of the VBI data into the original VBI format.

Method and apparatus for generic insertion of data in vertical blanking

A multiplex frame format for transmitting digital data in a data transmission system comprises a PACKETS portion comprising a highly error-protected region and a region having only Reed Solomon encoding as an error protection measure, the PACKETS portion including low speed data. The frame format also comprises portions for transmitting medium (AUDIO) and high speed (VIDEO) data streams following the PACKETS portion. Prior to transmission, the composed frame comprising the PACKETS, AUDIO and VIDEO portions is interleaved and the BLOCK SYNC and FRAME SYNC are added. A multiplex structure control packet word of the PACKETS portion immediately follows FRAME SYNC. Thus, the FRAME SYNC word defines where interleaving begins. A demultiplexer in concert with a microcontroller of a decoder decodes the multiplex structure control word and related PACKETS and outputs digital data streams to related output peripheral processors. The BLOCK SYNC word preferably comprises one eight bit byte and contains network signaling or other data at predetermined bit positions within the word. Moreover, the frame format is flexible and may vary in horizontal and vertical dimensions as digital service streams are varied due to service requirements or priorities. The multiplexers for forming the frame according to the present invention may be arranged in redundant (hot standby) or in multi-service arrangements synchronized by a synchronizing waveform, digitally generated to comprise a continuous 3.375 MHz portion and a single cycle frame marking signal of greater magnitude but significantly lower frequency.

System and method for transmitting a plurality of digital services

Synchronizing waveform generator

A receiver is provided for receiving a digital data stream over a communication path. The digital data is arranged as a sequence of frames, each frame including a plurality of lines of data. The beginning of each frame is indicated by a frame synchronization word; the beginning of each line is indicated by a horizontal synchronization byte. The data is interleaved by an encoder prior to transmission. The decoder contains circuitry for locating the horizontal and frame synchronization data and contains circuitry for deinterleaving the digital data. Both the synchronization locating circuitry and the deinterleaving circuitry require access to a memory, but not at the same time. Therefore, a single memory is used with the synchronization recovery circuitry and deinterleaving circuitry alternately addressing the memory.

Memory efficient method and apparatus for sync detection

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Scarborough, Canada

Paul D Nicholas