Abstract

Method and apparatus for creating a dynamic image on a television receiver display screen reflecting mood and character of music. Methods of pattern generation and color modulation are described. The pattern as seen by a viewer is a derived X-Y coordinate plot. The invention contemplates a format translator which is defined as a memory that samples an audio waveform periodically, determines the screen position corresponding to each sample, and stores video pulses in memory locations corresponding to those screen positions. The memory is then read in a line-by-line format for television display. The memory is thus written into in an X-Y format and read out in a raster scan format. Symmetry and variable image change rate can be employed in order to produce a pattern with pleasing effects. Image color is varied by shifting the phase of the chrominance sub-carrier as a function of the music envelope. Image color and intensity formation are then combined in an output mixer to produce a standard composite video output signal.