I've been using the live preview feature to get my camera view into OBS and it's been working great except the live preview is definitely not updating at the refresh rate that the Statistics box states, it seems like it's about half of that. Is there some way to get the live preview window in the app itself to run at a higher refresh rate?
The way live view works is the client polls the camera periodically for frame data, set the the "target FPS" control, limited to whatever throughput the client can sustain.
This is not synchronized with the actual refresh rate on the camera, and on CHDK ports without vid_get_viewport_live_fb implemented, only every third frame on the camera will actually be seen. What camera are you using?
In low light, some cameras may also reduce the physical refresh rate.
edit: Another thought that I had was that you might be able to achieve better quality and framerate at the expense of latency by streaming recorded video onto the host computer as a video file, in a format like mkv that can be read like a buffer.
Yeah, streaming video file data would potentially be good, but would require a bunch of reverse engineering that hasn't been done.
I've tried simply starting to record video and then starting a Pic&Video download but this doesn't seem to work, potentially because the camera is storing the video being recorded seperately then creating the DCIM file once it finishes.
This definitely won't work. While your computer may present the camera as something like a file system, it actually communicates using PTP, which is much more limited.