Methods for decoding or coding prediction mode, decoding or coding apparatus, and storage medium

A method for coding a prediction mode comprising:

• in response to determining that a merge mode is enabled for a current block and a current candidate prediction mode is allowed for the current block:
• acquiring enablement states of one or more to-be-traversed prediction modes, wherein the one or more to-be-traversed prediction modes comprise at least one candidate prediction mode used for predicting the current block, the at least one candidate prediction mode being different than the current candidate prediction mode;
• at a first time, in response to determining that a candidate prediction mode being allowed is present in the one or more to-be-traversed prediction modes, coding indication information of the current candidate prediction mode into a code stream, wherein the indication information is configured to indicate whether to enable the current candidate prediction mode for the current block;
• and
• at a second time, in response to determining that none of the one or more to-be-traversed prediction modes is allowed, not coding the indication information of the current candidate prediction mode into the code stream,
• wherein the method is executed by a processor.

A decoding apparatus comprising a processor configured to:

• in response to determining that a merge mode is enabled for a current block and a current candidate prediction mode is allowed for the current block:
• acquire enablement states of one or more to-be-traversed prediction modes, wherein the one or more to-be-traversed prediction modes comprise at least one candidate prediction mode used for predicting the current block, the at least one candidate prediction mode being different than the current candidate prediction mode;
• in response to determining that a candidate prediction mode being allowed is present in the one or more to-be-traversed prediction modes, decode indication information of the current candidate prediction mode from a code stream, wherein the indication information is configured to indicate whether to enable the current candidate prediction mode for the current block;
• and
• in response to determining that none of the one or more to-be-traversed prediction modes is allowed, determine that the current candidate prediction mode is used for the current block without decoding the indication information of the current candidate prediction mode from the code stream.

A coding apparatus comprising a processor configured to:

• in response to determining that a merge mode is enabled for a current block and a current candidate prediction mode is allowed for the current block:
• acquire enablement states of one or more to-be-traversed prediction modes, wherein the one or more to-be-traversed prediction modes comprise at least one candidate prediction mode used for predicting the current block the at least one candidate prediction mode being different than the current candidate prediction mode;
• in response to determining that a candidate prediction mode being allowed is present in the one of more to-be-traversed prediction modes, code indication information of the current candidate prediction mode into a code stream, wherein the indication information is configured to indicate whether to enable the current candidate prediction mode for the current block;
• and
• in response to determining that none of the one or more to-be-traversed prediction modes is allowed, not code the indication information of the current candidate prediction mode into the code stream.