Slow, continuous record plays back choppy/multiple images

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Ferguson
Posts: 33
Joined: Sat Feb 22, 2020 1:32 am

Slow, continuous record plays back choppy/multiple images

Post by Ferguson »

I have an ongoing issue and could use a pointer.

I record continuously at 4fps (limited in the camera settings) from 4k cameras both Hikvision and Lorex. The Blue Iris settings are Generic/ONVIFD, RTSP H.264/H.265/MJPG/MPEG4 and generally how it defaults. The issue is the same for Lorex and Hikvision.

Recording is set for Blue Iris DVR, Direct to Disk. The camera is set to full resolution, variable bitrate and highest quality with max bit rate of 4m, H.264, with iFrame set to 12.

The problem is that the playback (at 1x) is choppy, freezes periodically, and duplicates images in a weird ghosting way. Here is an example:

Image

This does NOT appear in live view with separate players, e.g. if I stream (in parallel) to my smart TV, nor when played on the web interface to Blue Iris live. At least I have never seen it there.

It DOES appear in the Blue Iris web display when playing recorded video clips and is the same as it appears in the console.

During console playback when it occurs, the displayed time stamp also does not move smoothly, but freezes up; since this is regenerated not stored in the video, it is likely a clue but not sure exactly what it means.

The CPU in use is fairly beefy (i7-6700, 64gb), it averages 14% busy while playing back. It is running windows 10 Pro updated fully, disk queues average in the 0.02 range and single percentages busy. There are 6 4k cameras at 4fps, so the system is basically loafing. The system runs headless and is dedicated to Blue Iris and some home automation processes that are lost in the background, Blue Iris is the only heavy processing program running on it.

For a given clip the problem is repeatable, in other words it is somehow baked into the recording not just an artifact or replay. If I export the clip it DOES appear in the export as well.

Anyone have ideas as to the root cause? Do I have something set up incorrectly? Is 3 sec (iFrame 12 at 4fps) too long for the iFrame?
Ferguson
Posts: 33
Joined: Sat Feb 22, 2020 1:32 am

Re: Slow, continuous record plays back choppy/multiple images

Post by Ferguson »

PS. Running Release 5.4.8.0 x64.
HeneryH
Posts: 678
Joined: Thu Jul 18, 2019 2:50 pm

Re: Slow, continuous record plays back choppy/multiple images

Post by HeneryH »

I've seen this a while back and think it was gremlins. I randomly played around with the iframe interval and frame rates in the camera settings and I think that might have fixed it.

Or... maybe my gremlins just moved to your machine.

I hate the iframe settings because as an engineer I am always doing unit analysis on my equations. Are the units of iframe "video-frames/iframe"?

That would mean that you are getting only one iframe every 3 seconds (as you noted). That might be the problem.
Ferguson
Posts: 33
Joined: Sat Feb 22, 2020 1:32 am

Re: Slow, continuous record plays back choppy/multiple images

Post by Ferguson »

As I understand it (and I almost certainly do not fully) the H.26x compressions depend on a periodic complete frame, then just send deltas. The periodic ghost looks a bit like a similar interval. I'll try using 1 vs 12 and see what happens, but I think one change is going to be vastly more data in both the stream and the on-disk storage.

One interesting thing I found on another forum was some indication this only happens in the blue iris storage format. I may try changing that also, though if the others do not permit viewing while writing in some way (as the GUI indicates) that could be a problem.

So off first to try iFrame to see its impact.

Thanks.
Ferguson
Posts: 33
Joined: Sat Feb 22, 2020 1:32 am

Re: Slow, continuous record plays back choppy/multiple images

Post by Ferguson »

So I am completely baffled.

i THINK that setting iframe to 1 helped. It seemed to, but I experimented tonight and could not reproduce it on cameras without that setting.

I THOUGHT that setting that to one would impact compression substantially, and make for larger files. The file size did not change. So I suspected the max bitrate (with VBR) was limiting it, so set it to 4 times the size (16384) and still no change in file size. Looked at transmission rate in the switch and also about the same.

Further testing needed. But if that's the solution I am kind of screwed, as I have 4 Lorex and 2 Hikvision, and cannot find an iFrame option on the Lorex.
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