I would like to minimize the processor time in arduino and googled some ppm encoder stuff. I found that the parallax propeller has multi core architecture with eight 32-bit risc cores. That device is commonly used as servo controller, but I would like to use it in opposite. Has anybody done something like that?
I was thinking about reading the channels and writing the pulse time to register, wich could be read with for example via I2C.
There are some old blog posts about this: http://diydrones.com/profiles/blogs/multichannel-rc-servo-signal
Examples about communication protocols for parallax propeller can be found on web.
Ps. Also the same controller could be used for driving the servos. If using 7 independent input channels/timers, the output can be done by the eight timer. So the input pulses can be with any freq or order and the output can run in another freq.