18524622. SPECTRAL SHAPE ESTIMATION FROM MDCT COEFFICIENTS simplified abstract (Telefonaktiebolaget LM Ericsson (publ))
Contents
SPECTRAL SHAPE ESTIMATION FROM MDCT COEFFICIENTS
Organization Name
Telefonaktiebolaget LM Ericsson (publ)
Inventor(s)
Martin Sehlstedt of LULEÅ (SE)
SPECTRAL SHAPE ESTIMATION FROM MDCT COEFFICIENTS - A simplified explanation of the abstract
This abstract first appeared for US patent application 18524622 titled 'SPECTRAL SHAPE ESTIMATION FROM MDCT COEFFICIENTS
Simplified Explanation
The abstract describes a method, decoder, and program code for controlling a concealment method for a lost audio frame. The method involves decoding two audio frames to obtain modified discrete cosine transform (MDCT) coefficients, determining spectral shapes based on these coefficients, transforming frame energies and spectral shapes into representations of FFT-based spectral analyses, detecting transient conditions, and modifying the concealment method by adjusting the spectrum magnitude of a substitution frame spectrum.
- Explanation of the patent/innovation:
- Decoding audio frames to obtain MDCT coefficients - Determining spectral shapes based on MDCT coefficients - Transforming frame energies and spectral shapes into FFT-based spectral analyses - Detecting transient conditions - Modifying concealment method by adjusting spectrum magnitude of substitution frame spectrum
- Potential applications of this technology:
- Audio signal processing - Error concealment in audio transmission
- Problems solved by this technology:
- Concealing lost audio frames in transmission - Improving audio quality in the presence of errors
- Benefits of this technology:
- Enhanced audio signal recovery - Improved user experience in audio playback
- Potential commercial applications of this technology:
- Audio streaming services - Telecommunication companies for audio transmission
- Possible prior art:
- Error concealment techniques in audio processing - Audio signal recovery methods in transmission systems
- Unanswered questions:
1. How does the method handle different types of audio frame losses? 2. What is the computational complexity of the concealment method?
Original Abstract Submitted
A method, decoder, and program code for controlling a concealment method for a lost audio frame is provided. A first audio frame and a second audio frame of the received audio signal are decoded to obtain modified discrete cosine transform (MDCT) coefficients. Values of a first spectral shape based upon the MDCT coefficients decoded from the first audio frame decoded and values of a second spectral shape based upon MDCT coefficients decoded from the second audio frame decoded are determined, the spectral shapes each comprising a number of sub-bands. The values of the spectral shapes and frame energies of the first audio frame and second audio frame are transformed into representations of FFT based spectral analyses. A transient condition is detected based on the representations of the FFTs. Responsive to detecting the transient condition, the concealment method is modified by selectively adjusting a spectrum magnitude of a substitution frame spectrum.
