HDTV multiplexed analogue components (HD-MAC)

HD- MAC( HDTV Multiplexed Analogue Components) was a further development of D2-MAC towards HDTV. HD-MAC had twice the number of lines of the PAL television standard, or D2-MAC, i.e. 1,250 lines, of which 1,152 were visible.

For compatibility reasons, however, the horizontal frequency of 15.625 kHz was retained from the PAL standard and from D2-MAC. With this line frequency, images with a high frame rate can be displayed flicker-free at 50 full frames per second, but with a relatively low resolution of only 288 lines; at 25 full frames per second, 576 visible lines are displayed, and at a low frame rate of 12.5 Hz, only the high resolution of 1,152 visible lines is achieved.

Since the picture was digitized, it was possible to avoid annoying flickering during slow scene changes. The additional information was to be processed with a D2-MAC signal via another transmission channel.

With HD-MAC, the recording is done with the full resolution of 2,048 x 1,152 pixels, and the four signals for brightness, chrominance, audio and additional data are transmitted one after the other in time. The video signals are transmitted in analog and the audio signal in digital. The resulting bandwidth is over 30 MHz.