Avesco Plc

Innovision Corporation

John C Clayton

David C Kneller

Trevor N Scofield

Trevor J Barnes

A sample rate converter comprises a first finite impulse response digital filter which effects a sampling rate doubling operation, which has a relatively large number of taps and whose output is connected to a second FIR digital filter having a relatively low number of variable coefficient taps. The frequency response of the first FIR digital filter is arranged to compensate for the frequency response of the second FIR digital filter.

Sample rate converter

A system for converting an input television signal that contains field sequences corresponding to frames in cine film is provided. The input signal is converted into an intermediate television signal wherein there is a direct correlation between the field groups thereof and the original film frames. The intermediate signal is modified to produce and output television signal whose field rate is that of a desired television signal. For example, the input signal can be an NTSC signal produced in part from a 3:2 pull down technique, the intermediate signal may be characterized by 625 lines and 48 fields per second or characterized by 525 lines and 625 fields per second, and the output signal can be a signal characterized by 625 lines and 50 fields per second. In each case, a 3:2 sequence of input signal fields (correlated with cine frames) results in pairs of fields in the output signal correlated with the cine frames. A television signal standards converter and a frame detector for use in the system are provided.

Video signal production from cinefilm originated material

Apparatus for and a method of decoding a video color signal provides a digital wide band luminance signal. An analog signal V1 representing the low band luminance component of a coded video color input signal Icv, is obtained at a first analog filter 1. An analog signal Yhc representing high band luminance and chrominance components is obtained at second means (5) which subtracts the first analog signal Y1 from a delayed input signal Icv. Signal Yhc is synchronously demodulated to provide (B-Y) and (R-Y) chrominance component signals U.sub.1, V.sub.1, which are digitized. Via digital delay means, single line delayed signals Yd1, U.sub.0, V.sub.0 and double line delayed signals U.sub.-1, V.sub.-1 are obtained. High band luminance signals Yu, Yv are then obtained as a function of at least two of the respective chrominance component signals U.sub.1, U.sub.0 and U.sub.-1 ; and V.sub.-1, V.sub.0 and V.sub.-1. These signals Yu, Yv are remodulated and combined to provide a digital high band luminance component signal Yh. Finally, by digitally summing the digital signals Yd1 and Yh a digital wide band luminance output signal Yd is obtained. Two different functions for obtaining the high band luminance components are exemplified. Wideband chrominance signals are also provided.

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Buckinghamshire, United Kingdom

John C Clayton