Where two or more video signals are combined or being switched between, the horizontal and vertical timing of the picture sources should be coincident with each other. If they are not, the picture will appear to jump when switching between the sources whilst the display device re-adjusts the horizontal and/or vertical scan to correctly reframe the image.
Where two or more video signals are combined or being switched between the horizontal and vertical timing of the picture sources should be coincident with each other If they are not the picture will appear to jump when switching between the sources whilst the display device re-adjusts the horizontal and/or vertical scan to correctly reframe the image