Data reproduction device, method thereof and storage medium

• US 20010047267A1
• Filed: 02/21/2001
• Published: 11/29/2001
• Est. Priority Date: 05/26/2000
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kato, Hideo, Abiko, Yukihiro, Koezuka, Tetsuo
• Granted Patent: US 7,418,393 B2
• Time in Patent Office: Days
• US Class Current: 704/500
• CPC Class Codes: G10L 21/04 Time compression or expansion

Abstract

A frame, which is the data unit, is extracted without decoding MPEG audio data. Then, a scale factor included in the frame is extracted and an evaluation function is calculated based on the scale factor. If the value of the evaluation function is larger than a prescribed threshold value, the speed of the frame is converted. If the value of the evaluation function is smaller than the prescribed threshold value, the frame is judged to be a frame in a silent section and neglected. The speed conversion is made by thinning out frames or repeating the same frame as many times as required according to prescribed rules.

Claims

1. A data reproduction device for reproducing compressed multimedia data, including audio data, comprising:

an extraction unit extracting a frame, which is unit data of the audio data;

a conversion unit thinning out the frame of the audio data or repeatedly outputting the frame; and

a reproduction unit decoding the frame of the audio data received from the conversion unit and reproducing voice.

2. A data reproduction device for reproducing compressed multimedia data, including audio data and also converting reproduction speed without decoding compressed audio data, comprising:

an extraction unit extracting a frame, which is unit data of the audio data;

a setting unit setting the reproduction speed of the audio data;

a speed conversion unit thinning out the frame of the audio data or repeatedly outputting the frame; and

a reproduction unit decoding the frame of the audio data received from the speed conversion unit and reproducing voice.

3. The data reproduction device according to

claim 2

, wherein the audio data are MPEG audio data.

4. The data reproduction device according to

claim 3

, further comprising:

a scale factor extraction unit extracting a scale factor included in the frame;

a calculation unit calculating the scale factor; and

a control unit comparing a calculation result of the calculation unit with a prescribed threshold value and controlling not to transmit a corresponding frame to said reproduction unit if the calculation result is smaller than the threshold value.

5. The data reproduction device according to

claim 4

, wherein said calculation unit calculates total of a plurality of scale factors included in the frame.

6. The data reproduction device according to

claim 4

, further comprising:

a scale factor conversion unit generating a scale factor conversion coefficient for compensating for a discontinuous fluctuation of an acoustic pressure caused in a joint between frames, calculating the scale factor and scale factor conversion coefficient and inputting them as data to be decoded to said reproduction unit if a plurality of scale factors included in the frame are reproduced by said reproduction unit.

7. The data reproduction device according to

claim 2

, which receives multimedia data, including both video data and audio data, further comprising:

a separation unit breaking down the multimedia data into both video data and audio data;

a decoding unit decoding the video data; and

a video reproduction unit reproducing the video data.

8. The data reproduction device according to

claim 7

, wherein each piece of the video data and audio data is structured as MPEG data.

9. A method for reproducing multimedia data, including audio data and converting a reproduction speed without decoding compressed audio data, comprising:

(a) extracting a frame, which is unit data of the audio data;

(b) setting the reproduction speed of the audio data;

(c) thinning out the frame of the audio data or repeatedly outputting the frame based on the reproduction speed set in step (b); and

(d) decoding the frame of the audio data received after step (c) and reproducing voice.

10. The data reproduction method according to

claim 9

, wherein the audio data are MPEG audio data.

11. The data reproduction according to

claim 10

, further comprising:

(e) extracting a scale factor included in the frame;

(f) calculating the scale factor; and

(g) comparing a calculation result in step (f) with a prescribed threshold value and controlling not to execute step (d) for a corresponding frame if the calculation result is smaller than the threshold value.

12. The data reproduction method according to

claim 11

, wherein in step (f), total of a plurality of scale factors included in the frame is calculated

13. The data reproduction method according to

claim 11

, further comprising

(h) generating a scale factor conversion coefficient for compensating for a discontinuous fluctuation of an acoustic pressure caused at a joint between frames and executing step (d) based on a value obtained by multiplying the scale factor by the scale factor conversion coefficient if a plurality of scale factors included in the frame are reproduced in step (d).

14. The data reproduction method for processing multimedia data, including both video data and audio data, according to

claim 9

, further comprising:

(i) separating video data from audio data;

(j) decoding the video data; and

(k) reproducing the video data.

15. The data reproduction method according to

claim 14

, wherein each of the video data and audio data is structured as MPEG data.

16. A computer-readable storage medium, on which is recorded a program for enabling a computer to reproduce multimedia data, including audio data by converting reproduction speed of compressed audio data without decoding the data, said process comprising:

(a) extracting a frame, which is data unit of the audio data;

(b) setting reproduction speed of the audio data;

(c) thinning out the frame of the audio data or repeatedly outputting the frame based on the reproduction speed set in step (b); and

(d) decoding the frame of the audio data received after step (c).

17. The storage medium according to

claim 16

, wherein the audio data are MPEG audio data.

18. The storage medium according to

claim 17

, further comprising:

(e) extracting a scale factor included in the frame;

(f) calculating the scale factor; and

(g) comparing a calculation result in step (f) with a prescribed threshold value and controlling not to execute step (d) for a corresponding frame if the calculation result is smaller than the threshold value.

19. The storage medium according to

claim 18

, wherein in step (f), a plurality of scale factors included in the frame is totaled.

20. The storage medium according to

claim 18

, further comprising

(h) generating a scale factor conversion coefficient for compensating for a discontinuous fluctuation of an acoustic pressure caused at a joint between frames and executing step (d) based on a value obtained by multiplying the scale factor by the scale factor conversion coefficient if a plurality of scale factors included in the frame are reproduced in step (d).

21. The storage medium for processing multimedia data, including both video and audio data, according to

claim 16

, further comprising:

(i) separating video data from audio data;

(j) decoding the video data; and

(k) reproducing the video data.

22. The storage medium according to

claim 21

, wherein each of the video data and audio data is structured as MPEG data.