Matsushita Electric Industrial Co., Ltd.

Seigo Asada

Masataka Higuchi

Shigeatsu Asari

Takeshi Morimoto

Kunio Sekimoto

A local server records compressed digital video data according to a first image compression format at normal and four times speeds, while a main server records compressed digital video data according to a second image compression format at normal speed. An image format converter converts compressed digital video data according to the first image compression format output at normal speed from the local server to compressed digital video data according to the second image compression format to be sent to the main server. The image format converter also converts compressed digital video data according to the second image compression format output at normal speed from the main server to compressed digital video data according to the first image compression format to be sent to the local server.

Compressed video data processing with conversion of image compression format

A local server records compressed digital video data according to a first image compression format at normal and four times speeds, while a main server records compressed digital video data according to a second image compression format at normal speed. An image format converter is provided between the local and main servers. The image format converter converts compressed digital video data according to the first image compression format output at normal speed from the local server to compressed digital video data according to the second image compression format to be sent to the main server. The image format converter also converts compressed digital video data according to the second image compression format output at normal speed from the main server to compressed digital video data according to the first image compression format to be sent to the local server. Then, compressed digital video data can be input and output at a high speed when digital video data compressed are recorded after the image conversion format is changed and compressed digital video data are output for reproduction after the image conversion format is changed.

A recording and reproducing apparatus for recording a video signal carrying a horizontal sync signal multiplexed with at least one another video signal into a serial mixed signal by compression along the time axis, or for recording such a signal without any compression along the time axis, wherein a pilot signal of a single frequency is superimposed in the horizontal blanking period of at least one video signal, and a clock is generated by use of the pilot signal of the mixed signal at the time of reproduction, thus eliminating time-axis variations appearing through recording and reproduction.

Video signal recording and reproducing apparatus

In a chrominance signal reproduction system for a colored image signal recording-reproducing apparatus in which two chrominance differential signals I and Q are frequency modulated and superimposed on each other to be recorded, and in the reproduction of the two modulated waves the carrier frequency f.sub.1 of the first modulated wave recorded in a low frequency band is converted to a higher carrier frequency f.sub.3 and demodulated, the higher carrier frequency f.sub.3 is selected so as to be separated from the sum frequency f.sub.1 +f.sub.2 component of the carrier frequency f.sub.2 component of the modulated wave recorded in the higher frequency band and the carrier frequency f.sub.1 component of the modulated wave recorded in the lower frequency by more than the frequency band of the demodulated signal. By setting the frequency f.sub.3 in this way, any beat interference can be eliminated from the reproduced signal of the signal recorded in the lower frequency band.

Growing community of inventors

Neyagawa, Japan

Seigo Asada