> ODD: > > bbbbxxxx > xxxxxxxx > ... > xxxxxxxx > xxxxxxxx > > EVEN: > > xxxxxxxx > xxxxxxxx > ... > xxxxxxxx > xxxxbbbb > I indeed saw half a line at the bottom too > Strictly speaking, you get a "1/2 pixel" flickering, not 1 pixel. I don't understand the 1/2 pixel notation, what I see is about 70 pizels that are quite black (with some noise) > > As you say, cams generate PAL signals this way, it has nothing to do > with the decoder. BT8x8 chips can detect the field parity, but several > time (= consecutive fields) is required in advance so that it stabilises > (see chip specs). This is not possible when switching cameras, since > there is never time enought to stabilise (provided you switch fast). > Well, it is possible if you use phase syncronised cams., which I believe > is not your case. yup :( we added a LM1881 > (a sync detector) chip in our board design and wired its ODD/#EVEN > output directly to one of the GPIO pins. This HW info IS reliable. what is LM1881 and how does IT know what is even and what is odd? > What we do is take any parity and if frames are odd, mark them at > interrupt time and interpolate (linear algorithm, just the mean of both > upper and lower pixels) them so that they "ressemble" even ones. > great tip, but it heavily depends on distinguishing even/odd frames, so the previos question... Michael Zayats
