Energy-based nonuniform time-scale modification of audio signals

• US 7,426,470 B2
• Filed: 10/03/2002
• Issued: 09/16/2008
• Est. Priority Date: 10/03/2002
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Lashkari, Khosrow, Chu, Wai C.
• Primary Examiner(s): Lerner; Martin
• Application Number:
  US10/264,042
• Publication Number:
  US 20040068412A1
• Time in Patent Office: 2,175 Days
• Field of Search: 704/503, 704/500, 704/267, 375/240.23, 370/470, 370/521
• US Class Current: 704/503
• CPC Class Codes: G10L 21/04 Time compression or expansion

Abstract

A method for energy based, non-uniform time-scale compression of audio signals includes receiving a frame of data corresponding to an input audio signal and segmenting the data into a plurality of segments. The method further includes estimating a value related to energy of the frame of data, determining a peak energy estimate for the frame, determining an energy threshold based on the peak energy estimate of the frame and comparing the value related to energy of the frame of the data with the energy threshold to control time-scale compression of the audio data.

Claims

1. A method for processing audio data, the method comprising:

receiving data corresponding to an input audio signal;

segmenting the data into a plurality of segments;

adjusting, using a processor, a time scale ratio between the input audio signal and an output compressed audio signal according to energy of a particular segment, wherein adjusting the time scale ratio comprises varying input segmentation length for the data;

maintaining a reservoir value to track effect of the varied input segmentation length on average segment length;

determining an input segmentation length for the data based in part on the reservoir value; and

providing the output compressed audio signal.

2. The method of claim 1 further comprising:

estimating the energy of the segments of the data.

3. The method of claim 1 wherein adjusting the time scale ratio comprises:

compressing less for relatively high-energy segments and more for relatively low-energy segments.

4. The method of claim 1 wherein segmenting the data includes segmenting based on the input segmentation length.

5. A method, comprising:

receiving data corresponding to an input audio signal;

segmenting the data into a plurality of segments;

adjusting, using a processor, a time scale ratio between the input audio signal and an output compressed audio signal according to energy of a particular segment, wherein adjusting the time scale ratio comprises;

varying input segmentation length for the data;

determining a reservoir value based on accumulated surplus or shortage with respect to a reference input segment length; and

adjusting input segmentation length for the data based at least in part on the reservoir value; and

providing the output compressed audio signal.

6. The method of claim 5 further comprising estimating the energy of the segments of the data.

7. The method of claim 5 wherein adjusting the time scale ratio comprises compressing less for relatively high-energy segments and more for relatively low-energy segments.

8. The method of claim 5 wherein segmenting the data includes segmenting based on the input segmentation length.