Method for Predicting Bandwidth Extension Frequency Band Signal, and Decoding Device

A method for predicting a bandwidth extension frequency band signal of an audio signal, comprising:

• obtaining, by a decoder, a decoded signal of a low frequency part of a current frame of the audio signal based on a received bitstream, wherein the audio signal comprises a plurality of frames;
• determining, by the decoder, whether a highest frequency bin of the decoded signal is less than a preset start frequency bin for bandwidth extension;
• when the highest frequency bin of the decoded signal is not less than the preset start frequency bin for bandwidth extension, predicting, by the decoder, an excitation signal of a bandwidth extension signal of a high frequency part of the current frame based on an excitation signal within a predetermined frequency range of the decoded signal, the highest frequency bin of the decoded signal, and the preset start frequency bin for bandwidth extension;
• reconstructing, by the decoder, the bandwidth extension signal of a high frequency part of the current frame based on the predicted excitation signal;
• and
• obtaining, by the decoder, a frequency domain signal of the current frame based on the decoded signal of the low frequency part of the current frame and the reconstructed bandwidth extension signal of the high frequency part of the current frame.

A decoder comprising:

• a memory for storing computer executable instructions;
• and
• a processor operatively coupled to the memory, the processor being configured to execute the computer-executable instructions to:
• obtain a decoded signal of a low frequency part of a current frame of the audio signal based on a received bitstream, wherein the audio signal comprises a plurality of frames;
• determine whether a highest frequency bin of the decoded signal is less than a preset start frequency bin for bandwidth extension;
• when the highest frequency bin of the decoded signal is less than the preset start frequency bin for bandwidth extension, predict an excitation signal of a bandwidth extension signal of a high frequency part of the current frame based on an excitation signal within a predetermined frequency range of the decoded signal and the preset start frequency bin for bandwidth extension;
• reconstruct the bandwidth extension signal of a high frequency part of the current frame based on the predicted excitation signal;
• and
• obtain a frequency domain signal of the current frame based on the decoded signal of the low frequency part of the current frame and the reconstructed bandwidth extension signal of the high frequency part of the current frame.

A decoder comprising:

• a memory for storing computer executable instructions;
• and
• a processor operatively coupled to the memory, the processor being configured to execute the computer-executable instructions to:
• obtain a decoded signal of a low frequency part of a current frame of the audio signal based on a received bitstream, wherein the audio signal comprises a plurality of frames;
• determine whether a highest frequency bin of the decoded signal is less than a preset start frequency bin for bandwidth extension;
• when the highest frequency bin of the decoded signal is not less than the preset start frequency bin for bandwidth extension, predict an excitation signal of a bandwidth extension signal of a high frequency part of the current frame based on an excitation signal within a predetermined frequency range of the decoded signal, the highest frequency bin of the decoded signal, and the preset start frequency bin for bandwidth extension;
• reconstruct the bandwidth extension signal of a high frequency part of the current frame based on the predicted excitation signal;
• and
• obtain a frequency domain signal of the current frame based on the decoded signal of the low frequency part of the current frame and the reconstructed bandwidth extension signal of the high frequency part of the current frame.