It is possible if you find the path for the substream try rtsp://IPADDRESS:554//Streaming/Channels/2..then you set up two separate cameras one for recording one for live...make the recorded camera hidden then uncheck display recorded cameras...I doubt you will see any performance gain..because now there are two streams that need to be dealt with..but it may help
Edit I changed the string...also use generic rtsp
I dont think this is going to help you much...because now you have blue iris pulling two distinct streams...a 720 stream uses little processing power to begin with.Thread resurrection over here, I know, but I had this same question and found an answer.
BI (at least for the cam I have which is a terrible $18 OV9712 1MP cam) will default upon auto-detect to /mpeg4 as a path, which is the main stream. It records, as well as gives live view/matrix display, from this main stream. I know that because I have resolution overlays on the two different streams and can differentiate between the two with the camera-generated OSD.
There was no documentation on how to get to the substream (no surprise there, lol) so I guessed at the URL/URI and ended up with 'rtsp://IPADDRESS:554//Streaming/Channels/1', which is a URL used by some hikvision cameras. Sure enough I got lucky and that was the substream. Here's how it looks in BI:
View attachment 8438
It reduced my bitrate from ~820kbps (720P @ 20fps) to ~140kbps (480x360 @ 2fps).
Next I'm going to use the substream for motion detection, which will then trigger recording of the main stream at full resolution and framerate. At least that's the plan. HTH
blue iris will always be pulling the 720 stream..it has to to get pretrigger frames and also not to lose a few seconds while it connects.@fenderman - I haven't messed around with it that much, but the idea is to not be processing the 720 stream at all until the 360P (substream) triggers it. I should be able to verify this through my switch traffic but haven't yet. Agreed it's not that big of a deal for my i7 server, but my a) short term goal is to have more (like, a lot) of crappy, cheap cams, and b) long term goal is to get a setup lean enough to run on a single ARM processor with OpenCV motion detection/NVR. That's down the road a way. We'll see