Yet another link, this one is written for Arduino in pure C (not Processing nor assembly)
http://hklab.net/wiki/TV_Video_Signal_Generator_with_Arduino
I'm a fortunate man because I have an oscilloscope and I have seen that
- delayMicroseconds doesn't work for delays lower than ~5us
- digitalWrite() is terribly sloooooow so don't use it
- When the loop() function finishes, there is a 10us extra delay (?)
Conclusion: don't use Processing to accomplish a hard real-time task like this. Use C or assembly.
Sorry for my poor english.
Regards,
Javi