The HDMI link does not support an explicit audio master clock; it carries information describing the relationship of the audio sample rate to the pixel clock. The ratio of the current pixel clock frequency to the desired MCLK frequency is defined by a numerator, N, and a denominator, CTS. Whenever the pixel clock frequency changes(for example, the video mode changes) or the audio clock changes(for example, the audio sampling rate changes), the N and CTS values change accordingly.
