pre and post capture for objects[Config Support]:

[Fswalle]

Describe the problem you are having

Hi, i read weeks for my problem, but I can´t fix it.
tested with frigate standalone docker, now running with ha supervised
I have to record active objects with pre & post capture, but it won´t work.
Why isn´t a really practicle example for questions like this ? only "read the docs", be shure i read them, not only once !
tried it with docker standalone since 0.16.1 weeks ago ...
and another question : what about "events", looks like that this worked in older versions ?

Using frigate+ with 2 corals
PLEASE help me, my nerves are burned out.
sorry for my bad english, i´m an old german

#EDIT# why is there only credit card option for sponsoring ? i don´t use this, paypal would be nice, because this program is amazing#
regards
Franz

Version

0.16.2-4d58206

Frigate config file

#should be enough

record:
  enabled: true
  retain:
    days: 1
    mode: all
  alerts:
    pre_capture: 10
    post_capture: 15
    retain:
      days: 7
      mode: motion ! also tried active_objects, should be better for me !
  detections:
    pre_capture: 10
    post_capture: 15
    retain:
      days: 7
      mode: motion ! also tried active_objects, should be better for me !

Relevant Frigate log output

n/a

Relevant go2rtc log output

n/a

Frigate stats

n/a

Operating system

Home Assistant OS

Install method

Proxmox via Docker

docker-compose file or Docker CLI command

n/a

Object Detector

Coral

Screenshots of the Frigate UI's System metrics pages

n/a

Any other information that may be helpful

system is running without any problems, was a hard journey ;)
the problem starts at beginning using frigate
using reolink cams (3x 811a and 2x duo2 poe ) and instar (9420 & 9820)

[inkeep-ai-assistant[bot]]

Based on the documentation, I can help clarify how pre_capture and post_capture work in Frigate.

How Pre/Post Capture Works

For pre_capture and post_capture to function, Frigate needs continuous recording segments available in cache to pull from(1). Your current configuration has record.retain.mode: all, which means all continuous recordings are kept, so that part is correct(1).

Your Configuration Issue

Your configuration structure looks mostly correct, but there's an important detail about how recordings work(1):

Recordings are written to cache first, then moved to disk only if they match your retention policy(1). This means:

1. Continuous recording segments are created in /tmp/cache/(1)
2. When an alert or detection occurs, Frigate pulls the pre_capture seconds from these cached segments(1)
3. After the event ends, it includes post_capture seconds(1)
4. The combined recording is then retained according to your alerts or detections retention settings(1)

Recommended Configuration

Based on the documentation, here's a clearer configuration for your use case(1):

record:
  enabled: true
  retain:
    days: 1
    mode: all
  alerts:
    pre_capture: 10
    post_capture: 15
    retain:
      days: 7
      mode: motion
  detections:
    pre_capture: 10
    post_capture: 15
    retain:
      days: 7
      mode: motion

(1)

Important Notes

• Pre-capture requires continuous recording: Without continuous recording enabled (record.enabled: true), pre-capture cannot work because there are no cached segments to pull from(1)(2)
• Mode matters: Using mode: motion will keep segments where motion was detected, while mode: active_objects keeps only segments with tracked objects that aren't stationary(1)
• Per-object customization: Currently, pre_capture and post_capture can be customized separately for alerts and detections, but not per individual object type(3)

What Changed from "Events"

The terminology shifted from "events" to the current structure of "alerts" and "detections" in recent versions(1). The functionality is similar, but the configuration structure is now more explicit about retention categories.

Troubleshooting Steps

1. Verify continuous recording is working by checking /media/frigate/recordings/(1)
2. Check that cache segments exist in /tmp/cache/ during operation(1)
3. Ensure your cameras are properly streaming and being recorded(1)
4. Check Frigate logs for any recording-related errors

Your configuration should work with these settings. If pre-capture still isn't functioning, there may be an issue with cache storage or camera stream stability.

**

📚 Sources:

1. Recording
2. [Config Support]: pre_capture not working for clip-only recording
3. Allow pre_capture and post_capture settings to be modified per object type

---

Have another question? Just tag @inkeep.

[NickM-27]

I think your understanding may be missing on how things work. Pre capture affects what is recorded, but it won't affect what is shown by the UI by default. Are you sure it is actually not recording, or just that it is not changing where the recordings open to?

[NickM-27]

you have it set to record 1 day with mode: all which means it will record everything for a day. If it is not recording what you expect then it sounds like your issue is not related to the what you are suggesting.

[Fswalle]

Well, I need mode all to be able to produce the corresponding segments for the pre and post, right? Or have I completely misunderstood something?

best regards
Franz

[NickM-27]

You already have that in your config

record:
  enabled: true
  retain:
    days: 1
    mode: all

so it is already recording everything for a day. So, again, if it is not recording everything then that has nothing to do with your record config and suggests there is some problem with your camera stream or something else

[Fswalle]

I'm only having streaming problems with one camera, but that's a self-inflicted issue with my transmission quality. The other six cameras are running without problems via a managed PoE switch.

It records, but the video lengths are incorrect during playback, both in terms of the subject and especially the time. With my configuration, there should always be a video that's 25+ seconds long. Segments before and after this video would be acceptable, but I can't understand the current behavior. Otherwise, the intended result doesn't make sense to me, because then I wouldn't need the pre- and post-recording commands at all, right?
I know that many people have this problems, maybe they are afraid to ask ( Just kidding )

Regards,
Franz

[NickM-27]

t records, but the video lengths are incorrect during playback

what do you mean by video lengths? again, it should be recording everything. Meaning there should be no gaps. When you are in the history view and using the timeline you can move the scrubber back or forward, and if recordings play then it was recorded.

It really does seem to me that multiple things are being conflated, and you are talking about what plays by default when you click on something in the UI. If that is the case, then as I already said, pre / post capture does not affect when the UI starts playing.

[Fswalle]

then that what I like to have doesn't work at all?
WebUI in frigate or home assistant or anything else won't play videos in this form?
for what is the pre and post recording good for?
it imho only makes sense to give the playback that I want to see, nothing else.
surfing the waves of the timeline is what I have to take?
ok, my fault.
is there another way to reach the goal ?

thx and regards
Franz

[NickM-27]

Where do you expect it to be shown? It is a recording config option, so how would it make sense to show it anywhere except where you review recordings.

[Fswalle]

No, I mean the playback behavior.

For example, cameras with this function: I set the pre- and post-recording time in the app, and that's exactly how it plays back, including the active object time. So, 10 seconds pre-recording time results in, for example, 33 seconds active object time, 15 seconds post-recording time results in a 58-second review clip.

According to you, this function isn't possible, and when I compare the timeline markers with the recordings themselves (reviews), I don't see that, for example, in my case, the markers are set 10 seconds before and 15 seconds after motion or active object detection (both are relevant to me), and the recording certainly isn't played back that way.

That's why I mentioned the Reolink software/app as an example. Unfortunately, we're obviously talking at cross purposes here, which is a shame...

thx and best regards
Franz

[NickM-27]

According to you, this function isn't possible,

That is not what I said. I explained multiple, simple ways to view what you're trying to view.

If you need to see more than that before you can do one of many things to easily do this:

• use the timeline to scrub back
• use the video overlay to go back 10 seconds
• use the left keyboard arrow to back 10 seconds

And again, post capture works by default because the UI plays continuously:

post_capture will always work by essence of the fact that the history view keeps playing

[Fswalle]

hey Nick,
I think you won't understand what I thought that it's possible, will you ?
Click => Full playback including the set times of pre and post.
So I understood, that this won't work at this time, and that's why I said, would be a big feature for future, imho.

So sry again for my bad english, thx for explaining and with best regards

Franz

[NickM-27]

The only thing missing from what you're describing is that it always starts 5 seconds before the activity started, not pre_capture. Everything else already functions exactly as you describe.