My real question is whether "filewrite" support, capture process time is faster? I'm writing a script based in multicam.lua to control 2 cameras (shoot and download), and I think that remoteshoot is the fastest option, is true?
That depends exactly what you want to do. In terms of shooting speed, there is generally not a huge difference between remote capture and capture to SD card, it will vary some depending on the camera, SD card speed and USB speed.
Remote capture will be faster than saving to the card and then downloading, but whether this matters depends on your application: Are you looking for minimum time between exposures, or minimum time to shoot and get the picture on your PC?
If you don't need to work with raw, then filewrite will let you remote capture with jpeg, which will be much faster than raw. Saving jpeg to sd card and downloading is probably also faster than any option using raw.
As far as using multicam goes, keep in mind that actual PTP calls in chdkptp are completely single threaded. Once you call a function that does data transfer (like con:download or con:capture_get_chunk) everything waits until that transfer is finished. So if you are shooting cameras simultaneously and want to use remote capture, you will need to integrate the logic from the cli remoteshoot command into your multicam code. You might also want to make a multi-cam aware version of chdku.lua con_methods:capture_get_data. If you just want to control both cameras, but don't mind shooting and downloading sequentially, then it should be much simpler.
