System for detecting a transmission error

A system for detecting a transmission error in picture data transmitted over a transmission line and non-coincidence of stored data in first and second frame memories, comprising:

• first inter-frame encoding equipment in an A station, operatively connected to the transmission line, for inter-frame encoding of the picture data prior to transmission;
• first inter-frame decoding equipment in a B station, operatively connected via the transmission line to said first inter-frame encoding equipment, for decoding the picture data;
• second inter-frame encoding equipment in the B station, operatively connected to the transmission line, for inter-frame encoding of the picture data prior to transmission;
• and
• second inter-frame decoding equipment in the A station, operatively connected via the transmission line to said second inter-frame encoding equipment, for decoding the picture data,
• said first and second inter-frame encoding equipment each comprising:
• a first frame memory having an input and an output;
• first operation error check work;
• and
• a multiplexer unit, operatively connected to said first operation means and the transmission line, for combining the first error check word and the picture data;
• and
• said first and second inter-frame decoding circuits each comprising:
• a second frame memory having an input and an output;
• separation means, operatively connected to the transmission line, for separating the first error check word and the picture data;
• second operation error check word;
• and
• comparator means, operatively connected to said separating means, said second operation means and said multiplexer unit, for comparing and checking the first and second error check words calculated by said first and second operation means to detect the transmission error and to detect non-coincidence of stored data in the first and second frame memories, and for generating a resending request signal when non-coincidence of the first and second error check words is detected in the B station, the resending request signal being combined with the first error check word and the picture data in said multiplexer unit of the B station and sent to said separating circuit in the A station, the resending request signal being transferred to said first frame memory in the A station, resulting in the picture data being processed in a reset mode for transmission of the picture data in combination with a reset display signal, said second frame memory in the B station being placed in a reset processing mode by the reset display signal.

An error check system for an inter-frame encoding/decoding system which encodes data by detecting a difference between frames of the data, said error check system comprising:

• an error code generator, comprising:
• first creating means, operatively connected to receive one of the frames, for creating first remainder data from the one of the frames;
• and
• combining means, operatively connected to said first creating means and to receive the difference between frames, for combining the first remainder data with the difference between frames;
• and
• an error checker, operatively connected to said error code generator, comprising:
• separating means, operatively connected to said combining means, for separating the first remainder data and the difference between frames;
• second creating means, operatively connected to said separating means, for creating second remainder data from the one of the frames;
• and
• comparing means, operatively connected to said separating means and said creating means, for comparing the first and second remainder data.

An inter-frame encoding/decoding apparatus for encoding television data to be transmitted over a transmission line and for decoding a received signal received over the transmission line from a similar inter-frame encoding/decoding apparatus, comprising:

• a first frame memory for storing a first picture frame of the television data;
• encoding means, operatively connected to said first frame memory and to receive the television data, for generating an encoded signal from a difference between the television data and the first frame;
• first operation means, operatively connected to said first frame memory and the transmission line, for separating the first picture frame into first bit groups each having a first corresponding number of bits with a predetermined logic level and for calculating first remainders by dividing the first corresponding number in each of the first bit groups by a predetermined value;
• decoding means, operatively connected to the transmission line, for decoding the received signal into a second picture frame;
• a second frame memory, operatively connected to said decoding means, for storing the second picture frame;
• second operation means, operatively connected to said second frame memory, for separating the second picture frame into second bit groups each having a second corresponding number of bits with the predetermined logic level and for calculating second remainders by dividing the second corresponding number in each of the second bit groups by the predetermined value;
• and
• comparing means, operatively connected to said receiving means and said second operation means, for comparing the first and second remainders to detect a transmission error.

A data checking method for inter-frame encoded data created using first frame data stored in a first frame memory, said memory comprising the steps of:

• (a) operating on the first frame data to produce first error check data;
• (b) transmitting the inter-frame encoded data and the error check data;
• (c) decoding the inter-frame encoded data to produce second frame data stored in a second frame memory;
• (d) operating on the second frame data to produce second error check data;
• and
• (e) comparing the first and second error check data to verify error-free reception of the inter-frame encoded data and coincidence of the first and second frame data.

A system for detecting and correcting a transmission error in picture data transmitting over a transmission line and non-coincidence of stored data in frame memories, comprising:

• inter-frame encoding equipment in an A station, operatively connected to the transmission line, for creating encoded data by encoding the picture data, said inter-frame encoding equipment comprising:
• a first frame memory having an input and an output;
• first operation means, operatively connected to one of the input and the output of said first frame memory, for calculating a first error check word;
• and
• a multiplexer unit, operatively connected to said first operation means and the transmission line, for combining the first error check word and the encoded data;
• and
• inter-frame decoding equipment in a B station, operatively connected via the transmission line to said multiplexer unit in said inter-frame encoding equipment, for decoding the encoded data, comprising:
• separation means, operatively connected to the transmission line, for separating the first error check word and the encoded data;
• a second frame memory having an input and an output;
• second operation means, operatively connected to said second frame memory, for calculating a second error check word;
• and
• comparator means, operatively connected to said separation means, said second operation means and the transmission line, for comparing and checking the first and second error check words calculated by said first and second operation means to detect the transmission error and non-coincidence of stored data in said first and second frame memories, for generating a resending request signal when non-coincidence of the first and second error check words is detected in the B station, and for transmitting the resending request signal to said first frame memory in the A station, said inter-frame encoding equipment in the A station responding to the resending request signal by processing the picture data in a reset mode and producing a reset display signal for combination with the picture data in said multiplexer for transmission over the transmission line, said second frame memory in the B station responding to the reset display signal by entering a reset processing mode.