Method and apparatus for karaoke scoring

• US 20050115383A1
• Filed: 11/24/2004
• Published: 06/02/2005
• Est. Priority Date: 11/28/2003
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Chang, Pei-Chen
• Granted Patent: US 7,304,229 B2
• Time in Patent Office: Days
• US Class Current: 84/616
• CPC Class Codes: G10H 1/361 Recording/reproducing of accompaniment for use with an external source, e.g. karaoke systems
• CPC Class Codes: G10H 2210/031 Musical analysis, i.e. isolation, extraction or identification of musical elements or musical parameters from a raw acoustic signal or from an encoded audio signal
• CPC Class Codes: G10H 2220/135 Musical aspects of games or videogames; Musical instrument-shaped game input interfaces

Abstract

A karaoke scoring apparatus includes a memory element, a feature extraction element, a similarity measurement element, and a scoring element. The karaoke system includes a reference audio input to be compared with a target audio input for giving a score. The reference audio input and the target audio input are sampled respectively and are transformed sequentially to plural frames of reference sampling signals and plural frames of target sampling signals. The memory element is used for storing the frame of reference sampling signal and the frame of target sampling signal. The feature extraction element is used for performing autocorrelation calculation on the frame of reference sampling signal and the frame of target sampling signal. The similarity measurement element is used for generating a similarity result. The scoring element is used for calculating the similarity results corresponding to the plural frames of sampling signals to output final score.

Claims

1. A karaoke scoring apparatus for scoring the performance of a singer with a karaoke system, the karaoke system comprising a predetermined reference audio input and being capable of accepting a target audio input compared with the reference audio input for giving a score by the karaoke scoring apparatus, the karaoke scoring apparatus respectively sampling the reference audio input and the target audio input, and sequentially transforming the reference audio input and the target audio input to a plural frames of reference sampling signals and a plural frames of target sampling signals, the karaoke scoring apparatus comprising:

a memory element for temporarily storing at least one frame of reference sampling signal and at least one frame of target sampling signal;

a feature extraction element for performing an autocorrelation calculation on the frame of reference sampling signal temporarily stored in the memory element and the plural frames of reference sampling signals that are differently delayed to generate a set of reference characteristic values, the feature extraction element for performing the autocorrelation calculation on the frame of target sampling signal temporarily stored in the memory element and the plural frames of target sampling signals that are differently delayed to generate a set of target characteristic values;

a similarity measurement element, according to the set of target characteristic values and the set of reference characteristic values, for performing a similarity comparing procedure to generate a similarity result corresponding to the frame of reference sampling signal and the frame of target sampling signal; and

a scoring element for calculating the similarity results corresponding to the plural frames of sampling signals to output a final score.

2. The karaoke scoring apparatus of claim 1, wherein the predetermined reference audio input comprises a reference instrumental input and/or a reference vocal input, and the target audio input is a target vocal input sang by the singer via a microphone.

3. The karaoke scoring apparatus of claim 1, wherein the memory element comprises a first register and a second register, the karaoke scoring apparatus sequentially transforms the reference audio input to a plural frames of corresponding reference sampling signals for temporarily storing in the first register, and the karaoke scoring apparatus sequentially transforms the target audio input to a plural frames of corresponding target sampling signals for temporarily storing in the second register.

4. The karaoke scoring apparatus of claim 3, wherein the predetermined sampling frequency is 44.1 KHz substantially, and each frame of reference sampling signal and each frame of target sampling signal have N samples respectively, N=1024.

5. The karaoke scoring apparatus of claim 4, wherein each frame of sampling signal can be represented as X(k), k=0˜

N−

1, and is able to be delayed as X(k+τ

) via different delay time τ

, and the autocorrelation calculation performs a predetermined calculation on X(k) and X(k+τ

) to obtain an autocorrelation function r_xx(τ

), the predetermined calculation is

$r_{\mathrm{xx}}<br><br>\left(\mathrm{\tau <br><br>}\right)=\frac{1}{N}<br><br>\underset{k=0}{\overset{N-1}{\sum <br><br>}}<br><br>\text{\hspace{1em}<br><br>}<br><br>x<br><br>\left(k\right)·<br><br>x<br><br>\left(k+\mathrm{\tau <br><br>}\right).$

6. The karaoke scoring apparatus of claim 5, wherein when the autocorrelation function r_xx(τ

) corresponding to the frame of reference sampling signals is generated, the karaoke scoring apparatus, according to a selection criterion for the reference characteristic value, selects a set of τ

values, τ

₀˜

τ

_Nr<sup>−

1</sup>, to be the set of reference characteristic values, the selection criterion for the reference characteristic value is as the following;

r_xx(τ

)≧

r_xx(τ

−

1), r_xx(τ

)≧

r_xx(τ

+1)
r_xx(τ

)≧

α

(MAX(r_xx(τ

))−

MIN(r_xx(τ

)))+MIN(r_xx(τ

))
τ

_lowerbound<

τ

≦

τ

_upperbound,

wherein α

is a predetermined constant, MAX(r_xx(τ

)) is the maximum value of the autocorrelation function r_xx(τ

) under the condition that τ

is not equal to 0, MIN(r_xx(τ

)) is the minimum of the autocorrelation function r_xx(τ

) under the condition that τ

is not equal to 0, τ

_lowerbound is a predetermined lower bound of τ

, and τ

_upperbound is a predetermined upper bound of τ

.

7. The karaoke scoring apparatus of claim 6, wherein the selection criterion for the reference characteristic value selects 3 largest values of the autocorrelation function r_xx(τ

) under the condition that τ

is not equal to 0, i.e. N_r=3, and the range of τ

is between 49 and 441.

8. The karaoke scoring apparatus of claim 5, wherein when the autocorrelation function r_xx(τ

) corresponding to the frame of target sampling signals is generated, the karaoke scoring apparatus, according to a selection criterion for the target characteristic value, selects a set of τ

values, τ

₀τ

_Nm<sup>−

1</sup>, to be the set of target characteristic values.

9. The karaoke scoring apparatus of claim 8, wherein the selection criterion for the target characteristic value selects the maximum of the autocorrelation function r_xx(τ

) under the condition that τ

is not equal to 0, i.e. N_m=1.

10. The karaoke scoring apparatus of claim 5, wherein the similarity comparing procedure performs a subtraction process between the set of target characteristic values and the set of reference characteristic values respectively, and if any absolute value of the subtraction results is smaller than a predetermined threshold, the result of similarity is a “

Hit”

, otherwise the result of similarity is a “

Miss”

.

11. The karaoke scoring apparatus of claim 10, wherein the reference audio input and the target audio input both comprise a plural audio of different pitches, each pitch has a corresponding central frequency and corresponds to at least one τ

, and each τ

of the set of reference characteristic values has a corresponding threshold (TH_τ

) which is obtained by the following equation;

${\mathrm{TH}}_{\mathrm{\tau <br><br>}}=<br><br>\frac{\mathrm{FS}}{<br><br>{\mathrm{FC}}_{\mathrm{upper}}+\mathrm{FC}<br><br><br><br>\frac{1}{2}}-\frac{\mathrm{FS}}{<br><br>{\mathrm{FC}}_{\mathrm{upper}}+\mathrm{FC}<br><br><br><br>\frac{1}{2}}<br><br><br><br>\frac{1}{2}=<br><br>\frac{\mathrm{FS}}{<br><br>{\mathrm{FC}}_{\mathrm{upper}}+\mathrm{FC}<br><br>}-\frac{\mathrm{FS}}{<br><br>{\mathrm{FC}}_{\mathrm{upper}}+\mathrm{FC}<br><br>}<br><br>,$

wherein FS represents a predetermined sampling frequency, FC represents the central frequency of the corresponding pitch of τ

, and FC_upper and FC_lower respectively represent the central frequency of two adjacent pitches of the corresponding pitch of τ

.

12. The karaoke scoring apparatus of claim 10, wherein the scoring element comprises a hitcount module and a misscount module, the hitcount module cumulatively calculates the Hits according to the result of similarity and outputs a hitcount value which is represented as HitCount, the misscount module cumulatively calculates the Misses according to the result of similarity and outputs a misscount value which is represented as MissCount, and the final score is between a predetermined maximum score (Score_Max) and a predetermined minimum score (Score_Min), which is calculated by the following equation:

$\mathrm{FinalScore}=\left({\mathrm{Score}}_{\mathrm{MAX}}-{\mathrm{Score}}_{\mathrm{Min}}\right)<br><br>\frac{\mathrm{HitCount}}{\mathrm{MissCount}+\mathrm{HitCount}}+{\mathrm{Score}}_{\mathrm{Min}}.$

13. The karaoke scoring apparatus of claim 12, wherein while the result of similarity is Hit, the hitcount module adds a hit-increase value to the present HitCount, which is represented as HitIncrease for generating a renewal HitCount, and replaces the MissCount by a default value, and while the results of similarity all are Hits continually, the HitIncrease increases.

14. The karaoke scoring apparatus of claim 12, wherein while the result of similarity is Miss, the misscount module adds a miss-increase value to the present MissCount, which is represented as MissIncrease for generating a renewal MissCount, and replaces the HitCount by a default value, and while the results of similarity all are Misses continually, the MissIncrease increases.

15. The karaoke scoring apparatus of claim 5, wherein the reference audio input and the target audio input both comprise a plural audio of different pitches, each pitch has a corresponding central frequency and a predetermined frequency range, and the similarity comparing procedure looks for that whether the corresponding frequencies of each the set of reference characteristic values and the set of target characteristic values are in the predetermined frequency range of the same pitch for generating the result of similarity.