APPARATUS AND METHOD FOR LOW COMPLEXITY COMBINATORIAL CODING OF SIGNALS

• US 20090100121A1
• Filed: 03/13/2008
• Published: 04/16/2009
• Est. Priority Date: 10/11/2007
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ashley, James P., Mittal, Udar
• Granted Patent: US 8,576,096 B2
• Time in Patent Office: Days
• US Class Current: 708/495
• CPC Class Codes: G06F 7/49942 Significance control
• CPC Class Codes: G10L 19/035 Scalar quantisation
• CPC Class Codes: G10L 19/20 using sound class specific coding, hybrid encoders or object based coding
• CPC Class Codes: H03M 7/30 Compression speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
• CPC Class Codes: H03M 7/3082 Vector coding for television signals, see H04N19/94

Abstract

During operation of an encoder, a signal vector (x) is received. A first multi-precision operand (Ψ′_k) will be generated based on the signal vector to be encoded. A mantissa operand and an exponent operand are generated. Both the mantissa operand and the exponent operand are representative of a second multi-precision operand that is based on the signal vector to be encoded. A portion of Ψ′_k is selected to be modified based on the exponent operand. A part of Ψ′_k is modified based on the mantissa operand to produce a modified multi-precision operand (Ψ′_k+1). Finally, a multi-precision codeword is generated for use in a corresponding decoder.

Claims

1. A method for operating an encoder that produces a codeword (C) from an input vector (x), the method comprising the steps of:

receiving the input vector to be encoded, wherein the input vector comprises speech, audio, image, or video signals;

generating a first multi-precision operand (Ψ

′

_k) based on the input vector;

generating a mantissa operand (M) and an exponent operand (h), wherein the mantissa operand and the exponent operand are representative of a second multi-precision operand (F′

(p_k,k)) that is based on the signal vector to be encoded;

selecting a portion of the first multi-precision operand to be modified based on the exponent operand;

modifying the portion of the first multi-precision operand based on the mantissa operand to produce a modified multi-precision operand (Ψ

′

_k+1); and

generating the codeword (c) based on the modified multi-precision operand;

wherein the codeword is for use in a corresponding decoder to decode the speech, audio, image, or video signals.

2. The method of claim 1 wherein Ψ

′

_k is based on a set of mantissa and exponent operands that are representative of F′

(p_i, i);

1≦

i<

k where p_i are the positions of the non-zero elements of the input vector x.

3. The method of claim 1 wherein M≈

└

2_kf ^f·

2_min(k<sup>i,lR)┘

.</sup>

4. The method of claim 1 wherein h is a function h is a function k_i.

5. The method of claim 1 wherein the portion of the first multi-precision operand Ψ

′

_k to be modified is represented by a location indicator defined by integers w_l and w_u.

6. The method of claim 5 wherein

7. The method of claim 1 wherein Ψ

′

_k+1=Ψ

′

_k+F′

(p_k,k).

8. The method of claim 1 wherein C_π

=Ψ

′

_v+1.

9. An encoder (100) comprising:

combinatorial coding circuitry (106) performing the steps of;

receiving a vector x to be encoded, wherein the vector x comprises speech, audio, image, or video signals;

generating a first multi-precision operand (Ψ

′

_k) based on x;

generating a mantissa operand (M) and an exponent operand (h), wherein the mantissa operand and the exponent operand are representative of a second multi-precision operand (F′

(p_k,k)) that is based on the signal vector to be encoded;

selecting a portion of Ψ

′

_k to be modified based on the exponent operand;

modifying the portion of Ψ

′

_k based on the mantissa operand and location indicator to produce a modified multi-precision operand (Ψ

′

_k+1); and

generating a codeword (C) based on Ψ

′

_k+1;

wherein the codeword is for use in a corresponding decoder to decode the speech, audio, image, or video signals.

10. The encoder of claim 9 wherein

11. The encoder of claim 9 wherein M ≈

└

2_k^f·

2_min(k^,ilR)┘

.

12. The encoder of claim 9 wherein h=min(O, k_i−

l_R).

13. The encoder of claim 9 wherein the portion of Ψ

′

_k to be modified is represented by a location indicator defined by integers w_i and w_u that identifies the words in the multi-precision codeword which are to be modified.

14. The encoder of claim 13 wherein

15. The encoder of claim 9 wherein Ψ

′

_k+1=Ψ

′

_k +F′

(p_k,k).

16. The encoder of claim 9 wherein Cπ

Ψ

′

_v+1.

17. A method for operating a decoder that generates a vector (x) from a codeword (C), the method comprising the steps of:

receiving the codeword (Cπ

);

generating a first multi-precision operand (Ψ

′

_k+1) based on Cπ

;

generating a mantissa operand (M) and an exponent operand (h), wherein the mantissa operand and the exponent operand are representative of a second multi-precision operand (F′

(p_k,k));

selecting a portion of Ψ

′

_k+1 to be modified based on the exponent operand;

modifying the portion of Ψ

′

_k+1 based on the mantissa operand and location indicator to produce a modified multi-precision operand (Ψ

′

_k);

decoding a position p<sub>k−

1</sub> of the (k-1)th non-zero elements of vector x;

generating the vector (x) based on the position p<sub>k−

1</sub> ; and

creating an output signal comprising speech, audio, image, or video based on the generated vector (x).

18. The method of claim 17 wherein

19. The method of claim 17 wherein M ≈

└

2^kf·

2^{min(ki, lR})┘

.

20. A decoder (300) comprising:

combinatorial coding circuitry (306) performing the steps of;

receiving the codeword (Cπ

);

generating a first multi-precision operand (Ψ

′

₊₁) based on Cπ

;

generating a mantissa operand (M) and an exponent operand (h), wherein the mantissa operand and the exponent operand are representative of a second multi-precision operand (F′

(p_k,k)) that is based on the signal vector to be encoded, selecting a portion of Ψ

′

_k+1 to be modified based on the exponent operand;

modifying the portion of Ψ

′

_k+1 based on the mantissa operand and location indicator to produce a modified multi-precision operand (Ψ

′

_k);

decoding a position p<sub>k−

1</sub> of the (p-<sub>k−

1</sub>)th non-zero elements of vector x; and

generating the vector (x) based on the position pk−

1.