Slow preview speed of events

Discussions related to the 1.36.x series of ZoneMinder
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ctrlsync
Posts: 4
Joined: Fri Dec 08, 2023 2:01 pm

Slow preview speed of events

Post by ctrlsync »

I have searched all over and can not seem to find an answer.

When I go to view a recorded event it plays fine. When I use the scroll bar at the bottom to jump to a specific section of that same event it slows the playback speed down to a second every 3 seconds making it very hard to watch a specific section of a clip. If I renew the page it will start playing correct speed from the beginning of the clip again.

System is Arch Linux ruining ZM 1.36.33

I never noticed this before I am not sure if its a new issue or I just overlooked it? Any help is appreciated. Logs does not show any errors.

Thanks.
dougmccrary
Posts: 1322
Joined: Sat Aug 31, 2019 7:35 am
Location: San Diego

Re: Slow preview speed of events

Post by dougmccrary »

Maybe you are inadvertently hitting the speed control just left of the volume control?
I'm seeing the speed change on my setups.
ctrlsync
Posts: 4
Joined: Fri Dec 08, 2023 2:01 pm

Re: Slow preview speed of events

Post by ctrlsync »

I do not have a volume control?

When I open an event to view it plays normal and the seconds in the corner move at real time. When I seek through the video using the gray bar that shows the different motion sections in the video the seconds slow down to a crawl and the video is very slow. One click in the seek bar does this. The speed button on my interface is a pull down menu not a button, unless I am missing something?
dougmccrary
Posts: 1322
Joined: Sat Aug 31, 2019 7:35 am
Location: San Diego

Re: Slow preview speed of events

Post by dougmccrary »

Here's a screenshot -
Screenshot from 2023-12-10 01-41-22.png
Screenshot from 2023-12-10 01-41-22.png (407.72 KiB) Viewed 23066 times
If you hover on the 1x you get a pop-up speed control. At least I do.
ctrlsync
Posts: 4
Joined: Fri Dec 08, 2023 2:01 pm

Re: Slow preview speed of events

Post by ctrlsync »

Nothing happens when I hover over the 1x on mine. My screen looks the same as yours maybe its the browser?

Either way when you click the seek bar to lets say the middle of the clip does your play speed slow down or run regular?
dougmccrary
Posts: 1322
Joined: Sat Aug 31, 2019 7:35 am
Location: San Diego

Re: Slow preview speed of events

Post by dougmccrary »

Nothing like that. Everything works as one might expect.
Sometimes old cookies cause problems. Try clearing the browser cache for zm.
Belfeldt
Posts: 4
Joined: Sun Nov 24, 2019 4:51 pm

Re: Slow preview speed of events

Post by Belfeldt »

It's not usually my style to revive old threads. But since I have exactly the same problem as the topic starter, I'm simply pushing the thread with the question of whether anyone has found a solution or at least an approach to a solution in the meantime.

zoneminder: v1.36.33
OS: debian 12 bookworm

Software and OS freshly installed three days ago. Load average is between 12 - 20 with 32 cores. RAM 47GB of 64GB occupied.
As already described, the problem occurs when you click on the timeline below the video. The stream first slows down considerably and then speeds up again after about 5 minutes (real time). If you click on a previous time period after the stream has accelerated back to normal, it even speeds up excessively.
There are 12 different cameras connected to the system. The problem occurs on all cameras and all browsers tested (Firefox, Edge on Windows 11, Firefox, Chromium on Linux Mint 21.3).
I am grateful for any ideas.
Belfeldt
Posts: 4
Joined: Sun Nov 24, 2019 4:51 pm

Re: Slow preview speed of events

Post by Belfeldt »

To make a long story short: The problem disappears if you leave the encoding to the cameras and set the "Video Writer" parameter to "Camera Passthrough". Previously, in my configuration, this parameter was set to "Encode" for all cameras and the associated sub-items were set to "Auto", partly for the sake of simplicity and partly out of laziness.
Presumably this and similar problems can be solved by familiarizing yourself with FFMPEG, its options and codecs in general. But this takes a lot of time.
I suspect that knowledge of I-frames aka key frames in particular will be the key to solving the problem.
dougmccrary
Posts: 1322
Joined: Sat Aug 31, 2019 7:35 am
Location: San Diego

Re: Slow preview speed of events

Post by dougmccrary »

I suspect that knowledge of I-frames aka key frames in particular will be the key to solving the problem.
Ha - wait til you see 1.38!
ctrlsync
Posts: 4
Joined: Fri Dec 08, 2023 2:01 pm

Re: Slow preview speed of events

Post by ctrlsync »

Belfeldt wrote: Wed Jun 12, 2024 3:20 pm To make a long story short: The problem disappears if you leave the encoding to the cameras and set the "Video Writer" parameter to "Camera Passthrough". Previously, in my configuration, this parameter was set to "Encode" for all cameras and the associated sub-items were set to "Auto", partly for the sake of simplicity and partly out of laziness.
Presumably this and similar problems can be solved by familiarizing yourself with FFMPEG, its options and codecs in general. But this takes a lot of time.
I suspect that knowledge of I-frames aka key frames in particular will be the key to solving the problem.
I just noticed this got an answer, and I still do not have mine fixed.

Where is that setting for me to try?
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