Patent ID: 6630962
Filing Date: 2003-10-07
Classification: G09G,H04N

Abstract:
Process for the frequency conversion utilizing a dynamic calculation of the interpolation phases, of an input video signal at a frequency F1 defined by a synchronization signal S1 into an output video signal at a variable frequency F2 defined by a synchronization signal S2, comprising a writing of the input signal to a memory on the basis of a write pointer PW and a reading, from the memory, to obtain the output signal, wherein it stores the position of the write pointer PW on receipt of the synchronization signal S1 so as to provide a value Pw-IN, and on receipt of the synchronization signal S2 so as to provide a value PW-OUT, in that it dynamically calculates an interpolation phase &agr; (12, 13, 14, 15) such that: Î±=PW_OUT-PW_INÎ”&it;â€ƒ&it;PW_FIELD&it;â€ƒ&it;if&it;â€ƒ&it;PW_OUT&GreaterEqual;PW_INorÎ±=PW_OUT+NCAP&CenterDot;Î”&it;â€ƒ&it;PW_FIELD-PW_INÎ”&it;â€ƒ&it;PW_FIELD&it;â€ƒ&it;if&it;â€ƒ&it;PW_OUT<PW_IN&Dgr;PWâ€”FIELD being the memory quantity required for the storage of a field or frame of the input signal and NCAP the capacity of the memory expressed in terms of number of fields or frames,and in that it performs a phase interpolation corresponding to this value.