Transient Signal Time-Envelope Encoding for Pre-Echo Recovery
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Solution Overview
Problem
Existing bandwidth extension technologies fail to effectively recover transient signals due to the lack of modification of their time envelopes, leading to pre-echo issues during decoding.
Innovation Solution
A method and device that modify the time envelope of transient signals by adjusting amplitude values to enhance the difference between sub-frames, ensuring the encoded signal accurately represents transient characteristics without increasing bit usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the time envelope of transient signals is not modified during encoding, then the encoding process is simple, but the recovered transient signal quality is poor due to pre-echo issues
Solution Approach 1:
The patent applies preliminary action by modifying the time envelope of transient signals during the encoding process before transmission. Specifically, it identifies transient signal segments and adjusts their time envelope characteristics (such as amplitude and decay rate) to prevent pre-echo artifacts from occurring during decoding. This preliminary modification ensures that when the signal is reconstructed at the decoder, the transient characteristics are preserved without requiring complex post-processing.
2Manufacturing precision
If more bits are used to encode transient signal characteristics, then the recovery quality improves, but the bit rate consumption increases
Solution Approach 1:
The patent applies parameter changes by modifying the time envelope parameters of transient signals (such as amplitude, decay rate, and envelope shape) during encoding. By adjusting these parameters to reflect the actual transient characteristics more accurately, the system can achieve better recovery quality without needing to allocate additional bits for extra signal data. The modified time envelope parameters are efficiently encoded using existing bandwidth extension techniques.
3Manufacturing precision
If standard bandwidth extension technology is used without transient signal detection, then the encoding is efficient, but the acoustic quality of transient signals deteriorates
Solution Approach 1:
The patent applies local quality by detecting transient signal segments within the overall audio signal and applying specialized time envelope modification only to these transient portions. The system uses transient detection algorithms to identify segments with rapid amplitude changes or specific spectral characteristics, then applies targeted time envelope adjustments only to these identified segments. This localized approach improves acoustic quality where needed while maintaining efficiency for non-transient portions of the signal.
Data Source
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AI summary
A transient signal encoding method and device, decoding method and device, and processing system are provided. The transient signal encoding method includes: obtaining a reference sub-frame where a maximal time envelope having a maximal amplitude value is located from time envelopes of all sub-frames of an input transient signal (11); adjusting the time envelope of the transient signal to highlight the characteristics of the transient signal; and writing the adjusted time envelope into bitstream (15).