Sound signal control device and method

1. A sound signal control device comprising:

a change determining unit to determine a change of a reproduction speed of input data containing a moving picture signal and a sound signal;

a changeover detecting unit to detect, as a changeover timing, a predetermined period in which a degree of coincidence of a moving picture is equal to or larger than a predetermined value when the change determining unit determines the change to a different reproduction speed during the reproduction;

a reproducing unit to reproduce a sound and the moving picture based on the input data and, when the change determining unit determines the change of the reproduction speed, changing over the reproduction speed at the changeover timing; and

a sound control unit to mute a sound output based on the sound signal at the changeover timing,

wherein the reproducing unit changes over the reproduction speed when the sound control unit mutes the sound output, and

the sound control unit cancels the mute within the predetermined period when the reproducing unit changes over the reproduction speed.

2. The sound signal control device according to claim 1 , wherein the detecting unit detects, if the degree of coincidence is equal to or larger than the predetermined value by making a comparison between the frames ranging from an Nth frame to an (N+x)th frame posterior to a predetermined frame counted from the Nth frame in the moving picture signal, a range from an (N+1)th frame to the (N+x)th frame as the changeover timing.

3. The sound signal control device according to claim 1 , wherein when the change determining unit determines a change to a 1× speed from the reproduction speed less than the 1× speed or a change to the 1× speed from the reproduction speed exceeding the 1× speed, the sound control unit mutes the sound output.

4. The sound signal control device according to claim 1 , further comprising:

a missing data detecting unit to detect missing data of the input data; and

a substitute data generating unit to generate substitute data, when the missing data detecting unit detects the missing data of the input data, by averaging units of the input which exclude data containing the missing data being detected,

wherein the substitute data is output for a reproduction time duration obtained by adding the reproduction time duration of the input data used for the averaging to the reproduction time duration of the data with the missing data being detected,

when the detecting unit detects the missing data of the input data, the change determining unit determines a change to the reproduction speed less than the 1× speed, according to a proportion of the number of data used for averaging and the number of substitute data, and

when the detecting unit comes to detect none of the missing data of the input data, the change determining unit determines a change to the 1× reproduction speed.

5. A sound signal control method by which a reproducing device of a sound and a moving picture executes:

determining a change of a reproduction speed of input data containing a moving picture signal and a sound signal;

detecting, as a changeover timing, a period in which a degree of coincidence of the moving picture is equal to or larger than a predetermined value when determining the change to a different reproduction speed during the reproduction;

reproducing the sound and the moving picture based on the input data and, when determining the change of the reproduction speed, changing over the reproduction speed at the changeover timing;

muting a sound output based on the sound signal at the changeover timing,

changing over the reproduction speed when the sound output is muted, and

canceling the mute within the predetermined period when the reproduction speed is changed over.

6. The sound signal control method according to claim 5 , wherein if the degree of coincidence is equal to or larger than the predetermined value by making a comparison between the frames ranging from an Nth frame to an (N+x)th frame posterior to a predetermined frame counted from the Nth frame in the moving picture signal, a range from an (N+1)th frame to the (N+x)th frame is detected as the changeover timing.

7. The sound signal control method according to claim 5 , wherein if the reproduction speed is changed to a 1× speed from the reproduction speed less than the 1× speed or to the 1× speed from the reproduction speed exceeding the 1× speed, the sound output is muted.

8. The sound signal control method according to claim 5 , further comprising:

detecting missing data of the input data; and

generating substitute data, when the missing data of the input data is detected, by averaging the input data which exclude data containing the missing data being detected,

wherein the substitute data is output for a reproduction time duration obtained by adding the reproduction time duration of the input data used for the averaging to the reproduction time

duration of the data with the missing data being detected,

when the missing data of the input data is detected, determining a change to the reproduction speed less than the 1× speed, according to a proportion of the number of data used for averaging and the number of substitute data, and

when coming to detect none of the missing data of the input data, a change to the 1× reproduction speed is determined.

9. A non-transitory recording medium recorded with a sound signal control program for making a reproducing device of a sound and a moving picture execute:

determining a change of a reproduction speed of input data containing a moving picture signal and a sound signal;

detecting, as a changeover timing, a period in which a degree of coincidence of the moving picture is equal to or larger than a predetermined value when determining the change to a different reproduction speed during the reproduction;

reproducing the sound and the moving picture based on the input data and, when determining the change of the reproduction speed, changing over the reproduction speed at the changeover timing;

muting a sound output based on the sound signal at the changeover timing,

changing over the reproduction speed when the sound output is muted, and

canceling the mute within the predetermined period when the reproduction speed is changed over.

10. The non-transitory recording medium recorded with the sound signal control program according to claim 9 , wherein if the degree of coincidence is equal to or larger than the predetermined value by making a comparison between the frames ranging from an Nth frame to an (N+x)th frame posterior to a predetermined frame counted from the Nth frame in the moving picture signal, a range from an (N+1)th frame to the (N+x)th frame is detected as the changeover timing.

11. The non-transitory recording medium recorded with the sound signal control program according to claim 9 , wherein if the reproduction speed is changed to a 1× speed from the reproduction speed less than the 1× speed or to the 1× speed from the reproduction speed exceeding the 1× speed, the sound output is muted.

12. The non-transitory recording medium recorded with the sound signal control program according to claim 9 , further comprising:

detecting missing data of the input data; and

generating substitute data, when the missing data of the input data is detected, by averaging the input data which exclude data containing the missing data being detected,

wherein the substitute data is output for a reproduction time duration obtained by adding the reproduction time duration of the input data used for the averaging to the reproduction time duration of the data with the missing data being detected,

when the missing

of the input data is detected, determining a change to the reproduction speed less than the 1× speed, according to a proportion of the number of data used for averaging and the number of substitute data, and

when coming to detect none of the missing data of the input data, a change to the 1× reproduction speed is determined.