Method, device and system for signal encoding and decoding

A signal decoding method, comprising:

• receiving a bit stream, wherein the bit stream comprises a core layer signal code and an enhancement layer signal code;
• determining a number of bits used by an enhancement layer;
• selecting, according to the core layer signal code and the determined number of bits, an enhancement sample point used in an enhancement layer signal decoding;
• decoding the enhancement layer signal code of the enhancement sample point to obtain an enhancement layer signal;
• and
• obtaining a modified core layer signal according to the enhancement layer signal and the bit stream.

A signal encoding device, comprising:

• a core layer encoding module, configured to encode a core layer signal to obtain a core layer signal code;
• at least one enhancement sample point selection module, configured to select, according to the core layer signal code and a determined number of bits that can be used by an enhancement layer, an enhancement sample point used in an enhancement layer signal encoding;
• at least one enhancement layer encoding module, configured to obtain an enhancement layer signal code of the enhancement sample point;
• and
• an outputting module, configured to output a bit stream, wherein the bit stream comprises the core layer signal code and the enhancement layer signal code.

A signal decoding device, comprising:

• a receiving module, configured to receive a bit stream, wherein the bit stream comprises a core layer signal code and an enhancement layer signal code;
• at least one enhancement sample point selecting module, configured to select, according to the received bit stream and a determined number of bits that can be used by an enhancement layer, an enhancement sample point used in an enhancement layer signal decoding;
• at least one enhancement layer decoding module, configured to decode the enhancement layer signal code of the enhancement sample point to obtain an enhancement layer signal;
• and
• a modifying module, configured to obtain a modified core layer signal according to the enhancement layer signal and the bit stream.