Scalable error detection and cross-session timing synchronization for packet-switched transmission

An apparatus, comprising:

• an electronic device configured to:
• encode a core layer of coded media data and at least one corresponding enhancement layer of the coded media data into the bitstream;
• compute a single checksum for the core layer;
• and
• add an additional field to each of the at least one enhancement layer such that any subsequent error check involving the respective at least one enhancement layer together with its respective additional field will match the single checksum if no data of the respective at least one enhancement layer or of its respective additional field is missing or in error, the single checksum thus being applicable for use in performing subsequent error checks of the core layer, and of each at least one enhancement layer, either alone or in combination with each lower corresponding enhancement layer and the core layer.

A method of processing encoded data from a bitstream, comprising:

• processing a core layer and at least one corresponding enhancement layer together with its respective additional field from the bitstream;
• processing a single checksum from the bitstream;
• and
• performing a check of one of the at least one corresponding enhancement layer, either alone or in combination with each lower corresponding enhancement layer and the core layer, using the single checksum, wherein the single checksum is usable regardless of the number of corresponding enhancement layers which are used in the check, and wherein an additional field has been previously added to each enhancement layer such that any subsequent check involving the respective enhancement layer together with its respective additional field will match the single checksum if no data of the respective enhancement layer or of its respective additional field is missing or in error.

An apparatus, comprising:

• an electronic device configured to:
• process a core layer and at least one corresponding enhancement layer together with its respective additional field from the bitstream;
• process a single checksum from the bitstream;
• and
• perform a check of one of the at least one corresponding enhancement layer, either alone or in combination with each lower corresponding enhancement layer and the core layer, using the single checksum, wherein the single checksum is usable regardless of the number of corresponding enhancement layers which are used in the check, and wherein an additional field has been previously added to each enhancement layer such that the check involving the respective enhancement layer together with its respective additional field will match the single checksum if no data of the respective enhancement layer or of its respective additional field is missing or in error.