A couple of error questions...

[JMartin]

I have been using Blue Iris 4 for a while now, and am learning as I go.
There are very few BI Training resources that I have found, and the help files are sometimes... well... not very helpful.

In my Blue Iris 4 log I see two things that keep happening:



The first is a "Clip Write Error" and I get this every once in a while... but not consistently.
I write Clips and Snapshots and Logs to a separate 3TB WD Purple drive that is almost empty... so it's not a space problem.

The second is that on occasion my Frame Rate gets adjusted, when I have them set (within the camera and in BI) to a specific (15FPS) rate.
Why do they keep adjusting. I have them set to 15 in order to relieve some Network and CPU load (which stays about 30%).

Can anyone shed some light on this?

 

[JMartin]

Oh.. and while I have your attention... can someone explain the difference between CBR and VBR (which I assume to be Constant Bit Rate and Variable Bit Rate)?
Just curious:



Thanx in advance for your guidance.

Jim

 

[fenderman]

@JMartin, blue iris will adjust the frame rate based on what the camera is sending. If you wish to lower the rate then you should do it in the camera. There could be many causes for clip write errors, like high cpu usage or setting the bitrate too high...

 

[JMartin]

@JMartin, blue iris will adjust the frame rate based on what the camera is sending. If you wish to lower the rate then you should do it in the camera. There could be many causes for clip write errors, like high cpu usage or setting the bitrate too high...

This is what puzzles me... I have all my cameras locked at 15 FPS on the main stream and 10 FPS on the sub-stream. Yet BI will still boost the frame rate up to 30?
(You can see this on the screen capture in my second post in this thread).

I have chosen lower bitrates also, but honestly I'm not sure what effect is has. (See also my second question about CBR vs. VBR).

 

[fenderman]

Blue iris cannot force the cameras to send more frames..what does blue iris report as incoming fps?

 

[JMartin]

So...
My camera is set to output 15 FPS...

I set that camera in BI to 15 FPS...

Several minutes later I see a log that says "FPS adjusted to 30.0"

Now camera again shows 30 FPS in BI, even though the Camera is internally set to 15 FPS and BI was also previously set to 15 FPS.

Does this have anything to do with the "Auto" checkbox? And it is ALWAYS grayed out, and cannot be un-selected.

Thoughts?

 

[fenderman]

@JMartin, you are looking at the wrong place. What is the frame rate shown in the general tab (or status page), that is the actual frame rate blue iris is receiving.
Auto cannot be changed - ..this was implemented a while back to solve ghosting issues. You can limited fps to 15 in other ways (in the record tab) but that will not reduce cpu consumption (may increase it) if the camera is still sending 30fps...
Point is if the camera is sending 30fps then having blue iris manually drop frames is a bad idea...if the camera is sending 15fps then you can disregard the fps changes in the messages.

 

[JMartin]

I assume you are referring to here:

This changes also. When all is working correctly, it reports something in the range of 14.xx to 15.xx FPS.
But then it changes for no explainable reason.
If I go back into the camera, it is still set to 15 FPS like it always has been.

This happens on more than one camera, but lately the specific camera I am showing you.

Thanx again for your assistance.

Jim

 

[JMartin]

Oddly... that very same camera that was showing 30 FPS in the General tab... if I let it sit on that tab long enough, it gradually slows to 15 FPS:


If I understand you correctly, this "dynamic" setting will ultimately adjust to whatever the camera puts out?
So trying to lock it to 15 FPS in BI is irrelevant if the camera is putting out more frames per second?

Ugh.

[Also, if the "Auto" can no longer be un-selected, I think it should just be removed... it's very confusing.]

 

[JMartin]

For the record... even though the individual camera (on the General Tab) shows that it's receiving 30 FPS, the "Camera" tab in the log shows the following:

 

[fenderman]

For the record... even though the individual camera (on the General Tab) shows that it's receiving 30 FPS, the "Camera" tab in the log shows the following:
View attachment 10007

They should both display the same number..doesnt matter really, if you are not having any issue with the stream...you can email support if it bothers you..
Yes, adjusting will do nothing, there is no point. Its set in the camera...as stated some cameras cannot properly send a specific frame rate so you can use the alt/timelapse to set it to 15, but there is no point because blue iris needs to spend cpu cycles tossing the extra frames.

 

[JMartin]

Understood, and thank you.
I'm trusting the "Camera's" tab for now then.
At the camera level (within the camera's interface) do you know what the difference between VBR and CBR is, and what it might effect?

 

[fenderman]

Understood, and thank you.
I'm trusting the "Camera's" tab for now then.
At the camera level (within the camera's interface) do you know what the difference between VBR and CBR is, and what it might effect?

CBR will keep the bitrate constant regardless of movement in the image...vbr will lower the bitrate when there is less movement/image changes..You basically can get more storage capacity with vbr..

 

[Warsaws]

What are the reasons someone may choose to use CBR?

 

[fenderman]

What are the reasons someone may choose to use CBR?

On some cheap cameras, vbr may cause pixelation problems at the beginning of a scene..generally on decent cameras this is not an issue and you can use VBR and the quality will be the same. You will gain storage capacity.