Video signal processing apparatus and video signal processing method

1. A video signal processing apparatus, comprising:

a decoder decoding an input video signal to generate a first standard video signal and a first non-standard video signal; and

a converter converting the first standard video signal into a second standard video signal of which a color subcarrier inverts a phase for each frame by using a first color subcarrier frequency, and converting the first non-standard video signal into a second non-standard video signal of which a color subcarrier inverts a phase for each frame by using a second color subcarrier frequency.

2. The video signal processing apparatus according to claim 1 , wherein two consecutive frames of the second standard video signal and the second non-standard video signal have an odd number of color subcarriers.

3. The video signal processing apparatus according to claim 1 , wherein the second standard video signal and the second non-standard video signal are output to a separator for separating a multiplexed signal with an oscillator for generating a signal having a substantially same frequency as the first color subcarrier frequency, and the second color subcarrier frequency falls within tolerance limits of frequency of the signal generated by the oscillator for a difference from the first color subcarrier frequency.

4. The video signal processing apparatus according to claim 3 , wherein absolute difference values of the second color subcarrier frequency from an upper limit and a lower limit of the tolerance are the maximum.

5. The video signal processing apparatus according to claim 1 , further comprising a selector for selecting the first color subcarrier frequency or the second color subcarrier frequency as a frequency used for conversion by the converter in accordance with a field frequency of the first standard video signal or the first non-standard video signal.

6. The video signal processing apparatus according to claim 1 , further comprising a picture size converter converting a picture size of the first standard video signal or the first non-standard video signal into a picture size of the second standard video signal or the second non-standard video signal.

7. The video signal processing apparatus according to claim 1 , wherein the first standard video signal and the second standard video signal have a field frequency of 23.976 Hz, 29.97 Hz, or 59.94 Hz, and the first non-standard video signal and the second non-standard video signal have a field frequency of 24 Hz, 30 Hz, or 60.00 Hz.

8. The video signal processing apparatus according to claim 1 , wherein the first standard video signal and the first non-standard video signal are ATSC video signals, and the second standard video signal and the second non-standard video signal are NTSC video signals.

9. The video signal processing apparatus of claim 1 , wherein the color subcarrier of the second standard video signal inverts its phase between the frames of the second standard video signal, and

wherein the color subcarrier of the second non-standard video signal inverts its phase between the frames of the second non-standard video signal.

10. The video signal processing apparatus according to claim 1 , wherein a frequency of the color subcarrier of the second standard video signal and a frequency of the color subcarrier of the second non-standard video signal are selected according to the phase of the color subcarriers of the second standard and non-standard video signal being inverted between the frames.

11. The video signal processing apparatus according to claim 1 , wherein two consecutive frames of the second standard video signal include a predetermined number of color subcarriers according to a frequency of the color subcarrier of the second standard video signal and the first color subcarrier frequency of the first standard video signal, and

wherein two consecutive frames of the second non-standard video signal include a predetermined number of color subcarriers according to a frequency of the color subcarrier of the second non-standard video signal and the second color subcarrier frequency of the first non-standard video signal.

12. The video signal processing apparatus according to claim 1 , wherein the first standard video signal and the second standard video signal have a field frequency in a range of 23.976 Hz to 59.94 Hz, and the first non-standard video signal and the second non-standard video signal have a field frequency in a range of 24 Hz to 60.00 Hz.

13. The video signal processing apparatus according to claim 1 , wherein a frequency of the color subcarrier of the second standard video signal and the second color subcarrier of the second non-standard video signal are set prior to converting by the converter according to substantially inverting the phase for each frame of the color subcarriers of the second standard and non-standard video signals.

14. A video signal processing method, comprising:

decoding an input video signal to generate a first standard video signal and a first non-standard video signal;

converting the first standard video signal into a second standard video signal of which a color subcarrier inverts a phase for each frame by using a first color subcarrier frequency; and

converting the first non-standard video signal into a second non-standard video signal of which a color subcarrier inverts a phase for each frame by using a second color subcarrier frequency.

15. The video signal processing method according to claim 14 , wherein two consecutive frames of the second standard video signal and the second non-standard video signal have an odd number of color subcarriers.

16. The video signal processing method according to claim 14 , wherein the second standard video signal and the second non-standard video signal are output to a separator for separating a multiplexed signal with an oscillator for generating a signal of the first color subcarrier frequency, and

wherein the second color subcarrier frequency falls within a range of tolerance limits that the oscillator of the separator allows a difference from the first color subcarrier frequency.

17. A video signal processing apparatus, comprising:

an ATSC (Advanced Television Systems Committee) decoder decoding an input ATSC video signal;

an NTSC (National Television Standards Committee) encoder encoding the decoded ATSC video signal with a color subcarrier frequency into an NTSC video signal; and

a determining section determining the color subcarrier frequency in accordance with a field frequency of the ATSC video signal in such a manner that frames of the encoded NTSC video signal are interleaved.

18. The video signal processing apparatus according to claim 17 , wherein the determined color subcarrier frequency is a frequency that satisfies a relational expression of: 2× color subcarrier frequency/field frequency=odd number.

19. The video signal processing apparatus according to claim 17 , wherein the determined color subcarrier frequency falls within tolerance limits of a quartz oscillator used for Y/S separation of the encoded NTSC video signal.

20. The video signal processing apparatus according to claim 17 , further comprising a picture size converter converting a picture size of the video signal decoded by the ATSC decoder into a picture size of the NTSC video signal,

wherein the NTSC encoder encodes the video signal the picture size of which is converted with the picture size converter into the NTSC video signal.