Encoder, Decoder, Encoding Method and Decoding Method for Frequency Domain Long-Term Prediction of Tonal Signals for Audio Coding

Simple SummaryContent extracted from patent full text and abstract with AI.

This invention introduces an advanced method for audio signal encoding and decoding focused on tonal (harmonic) audio signals, such as music or voiced speech. The system predicts and encodes audio signals in the frequency (transform) domain, using data from previous frames to estimate harmonic parameters efficiently. By modeling harmonic structures with linear equations and solving them with least mean squares, the invention improves audio compression, quality, and resilience to data loss, particularly for signals with strong tonal characteristics.

Use CasesContent extracted from patent full text and abstract with AI.

• Audio compression in music streaming services (e.g., Spotify, Apple Music) to reduce file size while maintaining high fidelity.
• Speech transmission for voice over IP (VoIP) and telecommunication systems where low latency and clarity are important.
• Broadcasting digital radio and television with efficient bandwidth usage and robust audio quality.
• Audio coding for portable devices (smartphones, MP3 players) with limited storage and processing resources.
• Professional audio recording, editing, and mastering, where maintaining high audio quality under compression is necessary.
• Error concealment during audio streaming where network losses can cause missing or corrupted audio frames.

BenefitsContent extracted from patent full text and abstract with AI.

• Improved compression efficiency, leading to lower bitrate requirements without compromising audio quality.
• Better audio quality for tonal signals, especially in low-delay and low-frequency-resolution scenarios.
• Enhanced resilience to signal loss or corruption, enabling frame-loss concealment and more robust streaming.
• Operates directly in the frequency domain, reducing computational complexity compared to time-domain methods.
• Flexible operation modes, allowing the encoder/decoder to select the optimal prediction method (frequency domain, time domain, adaptive) for each audio frame.
• Enables high-fidelity audio experiences for streaming, broadcasting, and communication, even under challenging bandwidth or error-prone conditions.

Technical Classifications (CPCs)

Inventors & Applicants

Patent Abstract

An encoder (100) for encoding a current frame of an audio signal depending on one or more previous frames of the audio signal according to an embodiment is provided. The one or more previous frames precede the current frame, wherein each of the current frame and the one or more previous frames comprises one or more harmonic components of the audio signal, wherein each of the current frame and the one or more previous frames comprises a plurality of spectral coefficients in a frequency domain or in a transform domain. To generate an encoding of the current frame, the encoder (100) is to determine an estimation of two harmonic parameters for each of the one or more harmonic components of a most previous frame of the one or more previous frames. Moreover, the encoder (100) is to determine the estimation of the two harmonic parameters for each of the one or more harmonic components of the most previous frame using a first group of three or more of the plurality of spectral coefficients of each of the one or more previous frames of the audio signal.