Television signal bandwidth reduction using variable rate transmission

• US 4,541,008 A
• Filed: 12/27/1982
• Issued: 09/10/1985
• Est. Priority Date: 12/27/1982
• Status: Expired due to Term

• Current Assignee: Jones Futura Foundation Limited
• Original Assignee: Jones Futura Foundation Limited
• Inventors: Nichols, James D., Fishman, Max
• Primary Examiner(s): Martin, John C.
• Assistant Examiner(s): Coles, Edward L.
• Application Number:
  US06/453,538
• Time in Patent Office: 988 Days
• Field of Search: 358/133, 358/105, 358/31, 358/142, 358/143, 358/137, 358/136, 358/138, 358/261, 358/13
• US Class Current: 375/240.01
• CPC Class Codes: H04N 11/042 Codec means
• CPC Class Codes: H04N 7/04 Systems for the transmission of one television signal, i.e. both picture and sound, by a single carrier H04N7/084, H04N7/087 take precedence

Abstract

A television signal transmission system incorporating circuits for processing and encoding a repetition reduced signal. The system contains a component separator for generating sampled digital values of the color and intensity components of a television signal, storage buffer for storing the separated components of the video signal, a data processor for comparing successive samples of the component video data and for generating variable-length blocks of data to represent either slowly varying signals or rapidly varying signals, circuitry for encoding and multiplexing audio and synchronization data into the signal stream, circuitry for encoding signal and control data for transmission to a receiver, circuit for processing the received signal to establish synchronization, circuit for demultiplexing the received signal to extract the audio information, and means for demultiplexing the component video information and reconstructing the composite video signal from the repetition-reduced representation.

Claims

1. A television signal transmission system incorporating means for processing encoding a repetition reduce signal, said system comprising:

a. a component separator for generating sampled digital values of the color and intensity components of a television signal,

b. buffer storage means for storing the separated components of the video signal,

c. data processing means for comparing successive samples of the component video data and for generating variable-length blocks of data to represent either slowly varying signals or rapidly varying signals,

d. means for encoding and multiplexing audio and synchronization data into the signal stream,

e. means for encoding signal and control data for transmission to a receiver,

f. means for processing the received signal to establish synchronization,

g. means for demultiplexing the received signal to extract the audio information, and

h. means for demultiplexing the component video information and reconstructing the composite video signal from the repetition-reduced representation,

wherein the signal data is divided into blocks containing a fixed number of input samples and whose output block sizes depend on signal content, and wherein a slowly varying input signal is represented by a reduced number of output samples, and a rapidly varying input signal is represented on a one-to-one basis at corresponding sampling points except where control information is introduced, and further

wherein a block of n samples representing a slowly varying input signal succeeded by a block representing another slowly varying input signal is represented by the first and middle samples of the former block;

or in the case of a block of n samples representing a segment of input data which is succeeded by a block representing rapidly varying data, the former block is represented by the first n-2 input samples while the last two input samples are replaced by rate-tags;

the rate-tags are control signals which have a magnitude of 0 units when the output segment contains no more than two clock intervals or a full-magnitude when the output segment length is greater than two clock intervals.

2. A system according to claim 1 and wherein rate-tag control data in the encoded signal is replaced by interpolated data in the reconstructed signal.

3. A system according to claim 1 and wherein the order of transmission of the representation of the component signals can be permuted on the basis of stored commands and whose order can be further modified by encrypted transmitted commands.

4. A system according to claim 1 wherein the size of the input-data block size can be selected in hardware or firmware and designated at the means for encoding by an encrypted command-status signal.