Hikvision/Dahua Third Stream with Blue Iris Substream option

fenderman

fenderman

Staff member
Mar 9, 2014
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Many users have taken advantage of the new BI substream option which allows BI to utilize the subtream for decoding, matrix view and now recording continuously until a triggered event, then going to full stream. This saves a ton of cpu. The downside is that in matrix view on a large screen the images can be blurry and that the continuous recording of the 640x480 substream does not produce an acceptable image for some. There is a middle ground.

Newer Dahua cameras by default allow a second substream up to 2mp. The default hik substream is limited to 640x480. Hikvision does allow a 1mp third stream as well however enabling is buried in the menu and requires some feature sacrifice (see image below) though options like the + codec are not compatible with BI anyways. See image below.

The dahua's ability to provide a 1080p second stream vs the 1mp max on the hik and also not having to sacrifice a feature set gives it an edge.
 

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Interesting. I didn't know Dahua had an advantage in this. I think it might become popular to max out the main stream, recorded on trigger, and have Blue Iris continuously record a 1080p sub stream at relatively low bit rate. This could be a viable alternative to just continuously recording the main stream at a medium or high bit rate all the time.

Anyway, people are bound to ask how to access the third stream in Blue Iris if it isn't available in the dropdown lists. It is simple, you typically just increase the stream number.

e.g. for Dahua
  • Main Stream: /cam/realmonitor?channel=1&subtype=0
  • First Sub Stream: /cam/realmonitor?channel=1&subtype=1
  • Second Sub Stream: /cam/realmonitor?channel=1&subtype=2

 
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@bp2008, if you enable the dahua second substream or third substream on hik then run find/inspect BI will show the new stream option.
 
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fenderman said:
@bp2008, if you enable the dahua second substream or third substream on hik then run find/inspect BI will show the new stream option.
Click to expand...

Not for me. My dropdown lists don't populate with anything besides none or (default) and I have to enter paths manually. No idea why.
 
Thanks fenderman, looks like the third stream (which was an available option once I did find inspect) visually looks like it will strike the right balance. Now to just go and change all the cameras and burn a few more hours on this :-) and see what my CPU looks like then.

So if I'm recording full-time will it be recording at the mainstream or the sub stream resolution? (which is now the third 720P stream)
 
JT Blue Iris said:
Interestingly though the third stream is limited to 6 FPS
Click to expand...
That is very strange, it should not be. Are you using a smart codec? what is your exposure set to? It will record whatever stream you tell it to record. You can also record substream continuous and third stream on motion detection.
 
You'll have to forgive me, I'm not sure where I check to see if I have a smart codec?
And when you say exposure, what do you mean by that?
Are these settings within the camera or BI?I
 
JT Blue Iris said:
You'll have to forgive me, I'm not sure where I check to see if I have a smart codec?
And when you say exposure, what do you mean by that?
Are these settings within the camera or BI?I
Click to expand...
both settings in the camera. smart codec would listed under video encoding (on the main profile) as h264+ or h265+ plus indicating smart - this is not compatible with BI anyway.
 
Smart codec is off.
Looks like on 4 megapixel camera I could only go 6 FPS on third stream, whereas on 8 megapixel camera I had the full range of options.
I have latest firmware updated on all cameras
 
JT Blue Iris said:
Smart codec is off.
Looks like on 4 megapixel camera I could only go 6 FPS on third stream, whereas on 8 megapixel camera I had the full range of options.
I have latest firmware updated on all cameras
Click to expand...
Its not related to the cameras megapixels. I have a bunch of hik 4mp cameras that allow up to 30fps on the third stream.
 
Using the third stream for viewing seems to hit the sweet spot :-)
where do I tell BI to record the mainstream?
Under the camera record tab all I see is a check box for use default, is this it?

and If so do I need to select default under stream profiles/main?
 
JT Blue Iris said:
Using the third stream for viewing seems to hit the sweet spot :)
where do I tell BI to record the mainstream?
Under the camera record tab all I see is a check box for use default, is this it?

and If so do I need to select default under stream profiles/main?
Click to expand...
Simply select continuous for the record option.
This will actually record both main and sub to be used during playback of multiple cams. You can force bi to record main only by unchecking the record dual stream if available but I would leave it checked.
 
Back on this,
one thing I notice is that within BI looking at the camera connection status that the frame and bit rate of the main and the sub streams seems to be the same even though I have set them differently within the camera. In other words if I increase or decrease the mainstream's frame rate both the main and sub streams go up and down within BI no matter what I have those set to within the camera..
 
I think I answered my own question, if I change the camera description from generic ONVIF to HIKVision, then this stream settings within the camera are reflected within BI
 
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