subcarrier signal under all circumstances application_number US 65835184 A description referring first to fig1 which illustrates an embodiment of the present invention an input television signal 1 is converted to pcm data 3 by an a d converter 2 and is then sent to a color flag mixer 4 where a signal representative of a color frame is added the pcm data from the color flag mixer 4 is written into a frame memory 5 under the control of a write in address wa the input television signal 1 is also supplied to a write clock generator 6 which includes a phase comparator 7 an oscillator 8 generating a clock of a frequency four times that of the color subcarrier and a frequency divider 9 dividing the frequency of the clock by four to produce a subcarrier frequency signal sc 10 the phase comparator 7 compares the phase of a burst signal which is extracted from the input television signal 1 and represented by a burst flag signal indicating the position of the burst signal with the phase of the subcarrier frequency signal 10 and sends the comparison result to the oscillator 8 which consists of a voltage controlled oscillator vco a write address generator 11 then generates the write in addresses for writing the pcm data into the frame memory 5 this write address generator 11 includes a horizontal h pulse separator 12 which extracts a horizontal sync pulse h pulse from the input television signal 1 a vertical v pulse separator 13 which extracts a vertical sync pulse v pulse therefrom a burst flag generator 14 which generates the burst flag signal in response to the h pulse an sch detector 15 which receives the h pulse and the subcarrier frequency signal 10 and.