"hardware accelerated decode" - even with direct to disc recording?

Post Reply
NGNeer314
Posts: 23
Joined: Tue Nov 26, 2019 9:40 pm

"hardware accelerated decode" - even with direct to disc recording?

Post by NGNeer314 » Sun Sep 27, 2020 2:52 am

I changed hardware acceleration from none to Nvidia NVDEC (this PC has a fancy gaming video card).

CPU usuage went from about 70% to %35. awesome! But I'm a little confused:

I have all my cameras set to record "direct to disk". I ASSumed that meant BI was just dumping the raw streams from the camera straight to the disk. So why would HW acceleration make such a big difference?
NGNeer314
Posts: 23
Joined: Tue Nov 26, 2019 9:40 pm

Re: "hardware accelerated decode" - even with direct to disc recording?

Post by NGNeer314 » Sun Sep 27, 2020 2:57 am

hmm, thinking about it, I guess BI still needs to decode the video streams to run the motion detection algorithms.... That makes sense. I'm glad I finally sat down to read and follow the "Optimizing Blue Iris's CPU Usage" wiki article!
HeneryH
Posts: 393
Joined: Thu Jul 18, 2019 2:50 pm

Re: "hardware accelerated decode" - even with direct to disc recording?

Post by HeneryH » Sun Sep 27, 2020 6:22 pm

You've got it. (and it needs to decode the stream to display it :) )

And, in the old days if you wanted on-screen overlays to be recorded you needed to have BI re-encode the stream again to save it to disk.

I think recent BI5 has improvements where overlays are stored in a database of some kind and can be regenerated on demand for replay. That isn't possible in BI4 without re-encoding the stream to disk.
Post Reply