For example, the standard 720p video format is 74.25MHz pclk, 45KHz Hclk, 60Hz vclk and so on.
Now I give a video whose VBI and Hsync are the same as the standard, so the ad9889b can recognize it as 720p.
The difference is that the pclk is little lower than 74.25MHz, so vclk become 57Hz or even lower 50Hz.
I found the hdmi tvout sometimes would output a black screen.
Wound the ad9889b always output what it receive?
For the black screen, is that because the tv receive a non-standard video or the tv receive a black image which ad9889b output?