Media error code generation as for a video inverse transport processor

In a system for receiving and decompressing packeted data including packets having signal payloads and further data useful for determining the integrity of the received packeted data, said system including memory in which respective payloads are sequentially stored, and wherein media error codes are to be inserted ahead of packet payloads when a data loss is detected, a method for inserting said media error codes comprising:

• storing a media error code in said memory in a sequence of memory address locations M+1 to M+N, prior to the occurrence of a packet payload where M and N are integers, and N is the number of address locations required to store the media error code;
• on the occurrence of a payload, storing said packet payload in said memory in further successive memory locations M+N+1 to M+N+K if a data loss has been detected;
• and
• if a data loss has not been detected, on the occurrence of a payload, overwriting said media error code by storing said packet payload in said memory in successive memory locations M+1 to M+K, where K is the number of memory address locations required to store a respective payload.

In a system for receiving and decompressing packeted video signal, including packets having compressed video signal payloads and further data useful for determining loss of packets, an inverse transport processor including a packet loss detector and a memory in which respective compressed video signal payloads are sequentially stored, and wherein media error codes are to be inserted ahead of compressed video signal payloads when a packet loss is detected, a method for inserting said media error codes comprising:

• storing a media error code in said memory in a sequence of memory address locations M+1 to M+N, prior to the occurrence of a packet payload where M and N are integers, and N is the number of address locations required to store the media error code;
• on the occurrence of a compressed video signal payload, storing said compressed video signal payload in said memory in further successive memory locations M+N+1 to M+N+K if a packet loss has been detected;
• and
• if a packet loss has not been detected, on the occurrence of a compressed video signal payload, overwriting said media error code by storing said compressed video signal payload in said memory in successive memory locations M+1 to M+K, where K is the number of memory address locations required to store a respective compressed video signal payload.

Apparatus for receiving signal occurring in packets, which packets respectively include a signal payload and further data which is indicative of the integrity of received signal, said apparatus comprising:

• an input port for receiving packeted signal;
• a memory;
• a source of a media error code;
• multiplexing means for coupling said source of media error code for storage of a media error code in said memory prior to occurrence of each packet payload, and on occurrence of respective packet payloads, coupling said input port to said memory for storage of respective packet payloads in said memory for overwriting th media error code stored in said memory when there is no loss of packet.