Hitachi, Ltd.

Ken Sodeyama

Eiji Moro

Hiroyuki Hori

Katsuyuki Watanabe

Akifumi Tabata

The present invention relates to a video signal processing apparatus for outputting an inputted video signal after subjecting the video signal to time axis correction, particularly to a video signal processing apparatus preferable in the case of subjecting the video signal to image compression. In the case in which a nonstandard signal is inputted to an image compression circuit of an MPEG2 encoder or the like, a drawback of freezing image or generating block noise or the like is resolved. A time axis correcting circuit stores an input signal to a memory and reads the input signal at a timing delayed from V synchronization of the input signal by a predetermined time period. For that purpose, a read synchronizing signal generator is reset at respective input field. A reset position is set to a position preceding the read V synchronization position by 3H through 10H. It is detected whether the input signal is a non-interlace signal or a field length thereof is deviated from a standard value and in these cases, odd/even order or synchronization timing of a synchronizing signal is corrected. Further, when the input signal is a nonstandard signal, the input signal is outputted without passing through the image compression circuit by a changeover switch.

Video signal processing apparatus

For horizontal sync information HD suitable for use in image processing module, e.g., module for TBC features, image compression recording/playback features, and LCD displaying features, it would be desirable that the time base fluctuations of the video input signal is faithfully reflected and that an interpolated HD generating feature is provided. A module for generating pulses generates the trailing edges of Csync as the trailing edge HD, and switches to an interpolated HD when a dropped pulse is detected after a few microseconds delay in the leading edge relative to the standard pulse. Thus, the trailing edge HD is selected within a time base fluctuation on the order of a few microseconds and the time base fluctuation is faithfully reflected and interpolation features can also be provided.

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Hitachinaka, Japan

Ken Sodeyama