Create sync signal for video data

[cjsha]

We have a CVBS -> USB converter for the camera. However, it does not provide a sync signal. I probed the pins of the IC on the CVBS -> USB adapter and translated the pin descriptions from this datasheet (translation below), yet I could not find a sync signal (nor an enable input). It seems like this will require additional hardware.

[cjsha]

I came across this "sync separator". This will be my first attempt at a solution.

[cjsha]

I don't think we'll need it, but just in case, I want to document this article (https://martin.hinner.info/vga/pal.html) which describes the PAL standard and goes a little bit of the NTSC standard as well.

[cjsha]

This is what the sync signal looks like in the oscilloscope:
Yellow channel 1: sync signal
Green channel 2: video input

This is what it looks like when I trigger on the first rising edge and give the board power:

There is a pulse when the LM1881 is receiving power. We'll need a way to filter this out. Probably in software.