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Old Mar 12, 2010, 04:53 PM
jimbob00 is offline
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it is impossible for me to measure the complete lag without having a synchronized clock on both sides, unless you have a better idea (?)

i know the theoretical "lag" introduced by my sound output is around 3ms (not calculated by me). the lag induced by the DX7 is also unknown.

The lag "feeling" is not reproducible or even quantifiable, there's just no lag feeling when the output is not in blocking mode, it feels instant. I think it's what matter when you fly, you push the stick and you don't feel any delay. (just like when you use smartproplus with a simu, you dont feel the delay)

The ppm signal is generated frame per frame (can't guess whats the next frame will be!) asynchronously and there's quite a bit of IPC in the python script, however this is happening quite fast.
this part is "timable", and i did just for you, it takes 0.006s max (and much less "low") on my pentium M 1.1ghz, including the print+timing calls, i think its discardable.
i timed from reading the joystick input (fdopen of /dev/input/js0) to write complete on the sound card.

I'm having more troubles on windows to achieve the same latency however, but eventually it'll be as quick.
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