I'm having difficulty getting the SD encoder test pattern to work with the ADV8005. Using an oscilliscope to probe the output shows the correct general pattern for NTSC, but the frame duration is incorrect and it appears to change as I change the speed of pixel clock routed to the encoder. Additionally, the phase seems to be unstable and monitors are not able to decode the frame. I've attached an image from the oscilloscope showing a single frame and the phase offset.
Two questions: How do I correctly route a stable clock to the encoder and why does the test pattern change with the input?