LPC residual signal encoding/decoding apparatus of modified discrete cosine transform (MDCT)-based unified voice/audio encoding device

• US 10,621,998 B2
• Filed: 08/04/2017
• Issued: 04/14/2020
• Est. Priority Date: 10/13/2008
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Beack, Seung Kwon, Lee, Tae Jin, Kim, Min Je, Kang, Kyeongok, Jang, Dae Young, Hong, Jin Woo, Seo, Jeongil, Ahn, Chieteuk, Park, Hochong, Park, Young-cheol
• Primary Examiner(s): Albertalli, Brian L
• Application Number:
  US15/669,262
• Publication Number:
  US 20170337929A1
• Time in Patent Office: 984 Days
• CPC Class Codes: G10L 19/087 using mixed excitation models, e.g. MELP, MBE, split band LPC or HVXC
• CPC Class Codes: G10L 19/125 Pitch excitation, e.g. pitch synchronous innovation CELP [PSI-CELP]
• CPC Class Codes: G10L 19/22 Mode decision, i.e. based on audio signal content versus external parameters
• CPC Class Codes: G10L 19/26 Pre-filtering or post-filtering

Abstract

Disclosed is an LPC residual signal encoding/decoding apparatus of an MDCT based unified voice and audio encoding device. The LPC residual signal encoding apparatus analyzes a property of an input signal, selects an encoding method of an LPC filtered signal, and encode the LPC residual signal based on one of a real filterbank, a complex filterbank, and an algebraic code excited linear prediction (ACELP).

Claims

1. A processing method performed by a device, comprising:

identifying a previous frame which has a speech characteristic to be coded by a first coding scheme;

identifying a current frame which has an audio characteristic to be coded by a second coding scheme; and

identifying additional information for cancelling a time-domain aliasing introduced by a Modified Discrete Cosine Transform (MDCT), when a switching occurs from the previous frame to the current frame, wherein the additional information is used for restoring the current frame;

adding (i) a first signal derived from a portion of the previous frame, (ii) a second signal derived from the additional information, and (iii) a third signal derived from the current frame, at a boundary between the previous frame and the current frame, wherein the additional information is different from the previous frame.

2. The processing method of claim 1, wherein the previous frame is coded with CELP (code-excited linear prediction), and the current frame is coded with MDCT (Modified Discrete Cosine Transform).

3. The processing method of claim 1, wherein the intentional information has length corresponds to a portion of entire length of the current frame.

4. A device, comprising at least one processor, wherein the processor is configured to:

identify a previous frame which has a speech characteristic to be coded by a first scheme;

identify a current frame which has an audio characteristic to be coded by a second scheme;

identify additional information for cancelling a time-domain aliasing introduced by a Modified Discrete Cosine Transform (MDCT), when a switching occurs from the previous frame to the current frame, wherein the additional information is used for restoring the current frame;

add (i) a first signal derived from a portion of the previous frame, (ii) a second signal derived from the additional information, and (iii) a third signal derived from the current frame, at a boundary between the previous frame and the current frame,

wherein the additional information is different from the previous frame.

5. The device of claim 4, wherein the previous frame is coded with CELP (code-excited linear prediction), and the current frame is coded with MDCT (Modified Discrete Cosine Transform).

6. The device of claim 4, wherein the intentional information has length corresponds to a portion of entire length of the current frame.

7. A processing method performed by a device, comprising:

identifying a previous frame which has a speech characteristic to be coded by CELP (Code Excited Linear Prediction);

identifying a current frame which has an audio characteristic to be coded by a MDCT (Modified Discrete Cosine Transform);

identifying additional information for compensating a time-domain aliasing introduced by the second coding scheme;

determining a first data corresponding to the additional information;

determining a second data using a specific portion of the previous frame;

determining a third data corresponding to the current frame; and

adding the first data, the second data and the third data, at a boundary between the previous frame and the current frame,

wherein the additional information is different from the previous frame.