Signal processing apparatus, signal processing method, and program therefor
AssigneeSony Corporation
InventorYoshiyuki Kobayashi
Life of this patent
Estimating the term…
Abstract
A signal processing apparatus subjects an audio signal to musical pitch analysis using different analysis techniques for the higher and lower frequencies. When an audio signal is input, a first extractor extracts a high-frequency signal, and a second extractor extracts a low-frequency signal from the audio signal. A high-frequency processor extracts pitch components from the high-frequency signal by applying the short-time Fourier transform. A low-frequency processor extracts pitch components from the low-frequency signal by dividing the low-frequency signal into a plurality of octave components. A synthesizing unit then combines the pitch components thus extracted from the high-frequency signal and the low-frequency signal and outputs the analysis result.
Claims20
A signal processing apparatus that analyzes an audio signal, comprising:
- first extracting means for extracting a high-frequency signal containing the higher frequencies from an input audio signal;
- second extracting means for extracting a low-frequency signal containing the lower frequencies from an input audio signal;
- high-frequency processing means for analyzing the plurality of pitch components contained in the high-frequency signal that was extracted from the audio signal, wherein the high-frequency signal is divided into a plurality of partially overlapping frames, the analysis being conducted using the short-time Fourier transform to apply a window function to each of the high-frequency signal frames and to apply a fast Fourier transform to each of the high-frequency signal frames for the analysis of the plurality of pitch components;
- low-frequency processing means for analyzing the plurality of pitch components contained in the low-frequency signal that was extracted from the audio signal, the analysis being conducted by first dividing the low-frequency signal into a plurality of octave components and then respectively extracting a plurality of pitch components from each octave component;
- and
- synthesizing means for combining the plurality of pitch components contained in the analyzed high-frequency signal with the plurality of pitch components contained in the analyzed low-frequency signal.
A signal processing method for use in a signal processing apparatus that analyzes an audio signal, and comprising the steps of:
- extracting a high-frequency signal containing the higher frequencies from an input audio signal;
- dividing the high-frequency signal into a plurality of partially overlapping frames;
- applying a window function to each of the plurality of the high-frequency signal frames;
- applying a fast Fourier transform to each of the high-frequency signal frames for the analysis of the audio signal;
- extracting a low-frequency signal containing the lower frequencies from an input audio signal;
- analyzing the plurality of pitch components contained in the high-frequency signal that was extracted from the audio signal, the analysis being conducted using the short-time Fourier transform;
- analyzing the plurality of pitch components contained in the low-frequency signal that was extracted from the audio signal, the analysis being conducted by first dividing the low-frequency signal into a plurality of octave components, and then respectively extracting a plurality of pitch components from each octave component;
- and
- combining the plurality of pitch components contained in the analyzed high-frequency signal with the plurality of pitch components contained in the analyzed low-frequency signal.
A non-transitory computer-readable medium containing program instructions for controlling a signal processing apparatus that analyzes an audio signal, the program instructions causing a computer of the signal processing apparatus to execute processing comprising:
- extracting a high-frequency signal containing the higher frequencies from an input audio signal;
- dividing the high-frequency signal into a plurality of partially overlapping frames;
- applying a window function to each of the plurality of the high-frequency signal frames;
- applying a fast Fourier transform to each of the high-frequency signal frames for the analysis of the audio signal;
- extracting a low-frequency signal containing the lower frequencies from an input audio signal;
- analyzing the plurality of pitch components contained in the high-frequency signal that was extracted from the audio signal, the analysis being conducted using the short-time Fourier transform;
- analyzing the plurality of pitch components contained in the low-frequency signal that was extracted from the audio signal, the analysis being conducted by first dividing the low-frequency signal into a plurality of octave components, and then respectively extracting a plurality of pitch components from each octave component;
- and
- combining the plurality of pitch components contained in the analyzed high-frequency signal with the plurality of pitch components contained in the analyzed low-frequency signal.
A signal processing apparatus that analyzes an audio signal, comprising:
- a first extractor configured to extract a high-frequency signal containing the higher frequencies from an input audio signal;
- a second extractor configured to extract a low-frequency signal containing the lower frequencies from an input audio signal;
- a high-frequency processor configured to analyze the plurality of pitch components contained in the high-frequency signal that was extracted from the audio signal, wherein the high-frequency signal is divided into a plurality of partially overlapping frames, the analysis being conducted using the short-time Fourier transform, to apply a window function to each of the high-frequency signal frames and to apply a fast Fourier transform to each of the high-frequency signal frames for the analysis of the plurality of pitch components;
- a low-frequency processor configured to analyze the plurality of pitch components contained in the low-frequency signal that was extracted from the audio signal, the analysis being conducted by first dividing the low-frequency signal into a plurality of octave components and then respectively extracting a plurality of pitch components from each octave component;
- and
- a synthesizing unit configured to combine the plurality of pitch components contained in the analyzed high-frequency signal with the plurality of pitch components contained in the analyzed low-frequency signal.
Dependencies are inferred from the claim text.